Novel conditional immunoconjugates

Abstract

In general, this invention relates to immunoconjugates, particularly immunoconjugates comprising at least one IL-15 receptor alpha (CD215) or a functional fragment thereof and a multivalent antibody comprising at least two antibody binding domains wherein the first antibody binding domain specifically binds to a first target antigen selected from the group consisting of NKG2D, NKp30, NKp46, NKp44 and DNAM-1; and the second antibody binding domain specifically binds to a second, different target antigen, optionally a tumour associated antigen (TAA). Additionally, this invention relates to polynucleotide molecules encoding said immunoconjugates. It also relates to vectors containing such polynucleotides and host cells comprising such polynucleotides. This invention additionally relates to methods for producing and purifying said immunoconjugates. Further, this invention relates to pharmaceutical compositions comprising said immunoconjugates, and uses thereof. The invention additionally relates to the use of such immunoconjugates in medicine, for example in the treatment of cancer.

Description

[0001] NOVEL CONDITIONAL IMMUNOCONJUGATES

[0002] FIELD OF THE INVENTION

[0003] In general, this invention relates to immunoconjugates, particularly immunoconjugates comprising at least one IL-15 receptor alpha (CD215) or a functional fragment thereof and a multivalent antibody comprising at least two antibody binding domains wherein the first antibody binding domain specifically binds to a first target antigen selected from the group consisting of NKG2D, NKp30, NKp46, NKp44 and DNAM-1; and the second antibody binding domain specifically binds to a second, different target antigen, optionally a tumour associated antigen (TAA). Additionally, this invention relates to polynucleotide molecules encoding said immunoconjugates. It also relates to vectors containing such polynucleotides and host cells comprising such polynucleotides. This invention additionally relates to methods for producing and purifying said immunoconjugates. Further, this invention relates to pharmaceutical compositions comprising said immunoconjugates, and uses thereof. The invention additionally relates to the use of such immunoconjugates in medicine, for example in the treatment of cancer.

[0004] BACKGROUND

[0005] Previously, a class of novel immunoconjugates was described in PCT / EP2024 / 053368, which is incorporated for reference in its entirety herein. Further background regarding IL-15 cytokines, IL-15 polypeptides, stresssensing receptors expressed on NK cells and gamma delta T-cells, NCR receptors and antibodies which bind to them is also described in PCT / EP2024 / 053368 and incorporated by reference herein. This prior invention related to enhancing the agonistic properties of antibodies which specifically target one receptor from a group consisting of NKG2D, NKp30, NKp46, NKp44 and DNAM-1 by the use of immunoconjugates provided therein. Particularly this invention related to immunoconjugates having at least two antibody binding domains, at least two IL-15 cytokine domains, and at least two CD215 domains (such as sushi domains). The resulting multivalent "dog-bone" immunoconjugate contained two antibody binding domains and two IL-15 cytokine binding domains and as such was termed a 2+2 multivalent approach. This ensured dual agonism and it was demonstrated that the immunoconjugates of the invention in PCT / EP2024 / 053368 had significantly augmented ability to target and activate specific immune cell types.

[0006] It was also discovered that for optimal effects, 'sequence order independent' co-engagement to both NKG2D and CD122 targets was important for optimal functionality of these multivalent immunoconjugates. Whilst not bound by theory, it was considered that such co-engagement may confer dual agonism effects via both the CD122 and NKG2D signaling axes. Therefore, preferred formats in PCT / EP2024 / 053368 featured the anti-NKG2D antibody binding domains being separated from the IL-15 polypeptides by antibody hinged-Fc regions in order to minimize steric hindrance and enable more optimal and more effective co-engagement of both targets irrespective of which target is engaged first.

[0007] This application builds on the prior work described in PCT / EP2024 / 053368, seeking to explore "conditionally active" immunoconjugate molecules, wherein the technical effects conferred by the immunoconjugates are conditional to the immune and cellular environment and cell types in which the immunoconjugates are located or distributed to. Such conditionally active molecules are particularly suitable in certain scenarios. For example, they may be particularly suitable for use in novel highly targeted cancer treatment regimens by preferentially targeting (i) a sub-set of immune cells and / or (ii) immune cells proximal to cancer cells.

[0008] SUMMARY OF THE INVENTION

[0009] A variety of different approaches were undertaken to explore conditionally active variants. Throughout this application reference is made to 2+2, 2+1+1, 1+1+1 formats. The first numeral refers to the number of IL-15 receptor alpha (CD215) domains (each containing a sushi domain) or of IL-15 receptor alpha (CD215)+l L-15 domains (also referred to as sushi-IL-15 domains) are present, the second numeral refers to the number of NKG2D or NKp30 or NKp46 or NKp44 or DNAM-1 antibody binding domains present and the third numeral refers to the number of second binding domains to a second antigen. The difference between these formats are provided Table 1. To further guide, supporting example designs are also presented in Figure 1 wherein additional building block formats are also referenced as indicated and to further aid understanding.

[0010] TABLE 1:

[0011] Given the highly agonistic effects of the starting exemplar 2+2 format as described PCT / EP2024 / 053368, it was conceived there was enough agonism 'headroom' to dial down activity by replacing for example one of the anti-NKG2D binding domains which bound the first NKG2D antigen with a second binding domain which bound a second, different antigen such as a tumour associated antigen (TAA) (a 2+1+1 format). Whilst the resulting 2+1+1 molecule may have less capacity to cross-link NKG2D receptors (given no avidity effects with only one NKG2D binding domain present now), it was conceived that upon co-engagement of the second antigen (such as a TAA) expressed on a proximal second cell, the desired NKG2D cross-linking / agonism effects may be recreated - particularly if the most agonistic anti-NKG2D antibody binding domain was employed. Finally, and independent of agonism effects, another advantage of this 2+1+1 format is that the resulting IL-15 is delivered to a sub-set of NKG2D / CD122 positive cells that are most proximal to the cancer cells expressing the second TAA antigen.

[0012] It was additionally discovered that varying the length, nature and / or presence of the linkers described in PCT / EP2024 / 053368 led to optimization of the formatting of the complex immunoconjugates, as will be described herein. Further, it was discovered that formats in which the IL-15 cytokine is not covalently bound to the immunoconjugate but instead supplied 'in trans' from a separate expression cassette (and so resulting in I L_15 cytokine being non-covalently bound to the sushi domain) resulted in even more favourable homogeneity profiles and yields during production. This will be described further herein.

[0013] Therefore, in a first aspect the present invention provides an immunoconjugate comprising: a. a multivalent antibody or antigen-binding fragment thereof comprising: i. at least two antibody binding domains wherein:

[0014] 1. the first antibody binding domain specifically binds to a first target antigen selected from the group consisting of NKG2D, NKp30, NKp46, NKp44 and DNAM-1; and

[0015] 2. the second antibody binding domain specifically binds to a second, different target antigen; ii. a human immunoglobulin Fc domain comprising:

[0016] 1. a first chain comprising in an N- to C- terminal direction a CH2 domain and a CH3 domain; and

[0017] 2. a second chain comprising in an N- to C- terminal direction a CH2 domain and a CH3 domain; and b. at least one I L-15 receptor alpha (CD215) or a functional fragment thereof covalently linked to at least one C-terminus of the Fc domain.

[0018] The first antibody binding domain may specifically bind to NKG2D and may comprise a heavy chain variable region (VH) comprising a heavy chain complementary determining region (HCDR) 1 of SEQ ID NO: 6, a HCDR 2 of SEQ I D NO: 19, and a HCDR 3 of SEQ ID NO: 32; and a light chain variable region ( VL) comprising a light chain complementarity determining region (LCDR) of SEQ I D NO: 45, a LCDR 2 of SEQ ID NO: 58, and a LCDR 3 of SEQ ID NO: 71.

[0019] The second antibody binding domain may specifically bind to a tumour associated antigen (TAA). The TAA may be selected from the group consisting of HER2, EGFR, CD19 and CD20. Preferably, the second antibody binding domain specifically binds to a second target antigen which is HER2.

[0020] The CH3 domain of the first chain may comprises or consist of the sequence of SEQ ID NO: 270 and / or the CH3 domain of the second chain may comprises or consist of the sequence of SEQ ID NO: 271.

[0021] The IL-15 receptor alpha (CD215) fragment(s) may comprise the IL-15 receptor alpha (CD215) sushi domain, preferably wherein the IL-15 receptor alpha (CD215) sushi domain(s) is a human I L-15 receptor alpha (CD215) sushi domain(s).

[0022] The immunoconjugates may further comprise at least one human IL-15 cytokine or a functional fragment thereof covalently linked to the C-terminus of at least one IL-15 receptor alpha (CD215) or functional fragment thereof. In alternate embodiments, the immunoconjugate does not comprise a covalently linked IL-15 cytokine and comprises one or more human I L-15 cytokine(s) or fragment(s) thereof non-covalently bound to one or more IL-15 receptor alpha (CD215) or a functional fragment thereof.

[0023] In a second aspect of the invention there is provided a method of producing an immunoconjugate of the invention, comprising (a) culturing the host cell of the invention under conditions suitable for the expression of the immunoconjugate, and optionally (b) recovering and purifying the immunoconjugate. Immunoconjugates obtained or obtainable by such methods are also provided.

[0024] In a third aspect of the invention there is provided one or more isolated polynucleotides encoding an immunoconjugate of the invention or encoding one or more chains of an immunoconjugate of the invention. In a fourth aspect of the invention, there is provided a vector, particularly an expression vector, comprising a polynucleotide of the invention

[0025] In a fifth aspect of the invention there is provided a host cell comprising one or more polynucleotides or one or more vectors of the invention.

[0026] In a sixth aspect of the invention there is provided a composition comprising an immunoconjugate of the invention. The composition may be a pharmaceutical composition and may comprise one or more pharmaceutically acceptable carriers.

[0027] In a seventh aspect of the invention there is provided an immunoconjugate, composition or pharmaceutical composition according to the invention for use as a medicament, or for use in the treatment of a disease in a patient, which may be cancer. There is also provided the use of an immunoconjugate according to the invention in the manufacture of a medicament for the treatment of a disease in a patient, which may be cancer. Also provided is an immunoconjugate, composition or pharmaceutical composition according to the invention for use in stimulating the immune system of an individual. Also provided is the use of an immunoconjugate according to the invention in the manufacture of a medicament for stimulating the immune system of an individual.

[0028] In an eighth aspect of the invention there is provided a method of treating disease in an individual, comprising administering to said individual a therapeutically effective amount of an immunoconjugate, composition or pharmaceutical composition of the invention to a subject in need thereof. The disease may be cancer.

[0029] In a ninth aspect of the invention is provided is a method of stimulating the immune system of an individual, comprising administering to said individual an effective amount of an immunoconjugate, composition or pharmaceutical composition of the invention to a subject in need thereof.

[0030] BRIEF DESCRIPTION OF THE FIGURES

[0031] Figure 1: Schematic of Exemplar formats. (A) Example formats all containing 2 copies or 1 copy of an IL-15 polypeptide comprising a sushi-domain covalently joined by a linker to an IL-15 domain and prefixed as "2+" or "1+" accordingly. From left to right, the 2+2 variant (variant also described in PCT / EP2024 / 053368) contains 2 copies of an anti-NKG2D binding domain; the 2+1+1 variant contains one copy of the anti-NKG2D binding domain and one copy of a second binding domain such as an anti-TAA binding domain; the 1+1+1 variant contains one copy each of sushi-l L15, anti-NKG2D binding domain, and second binding domain such as an anti- TAA binding domain. Additionally presented are the modular building blocks: First the "2+ [ ] + [ ]" and the "1+ [ ] + [ ]" complexes as indicated contain one or two copies of the sushi-l L15 domain (with 2x Fabs to be added at the N-terminus). Second the "2+1+ [ ]" and "1+1 [ ]" complexes as indicated contain one or two copies of the sush i-l L15 domain, one copy of the anti-NKG2D domain, with one second binding domain such as an anti-TAA binding Vh / VI domain to be added where indicated. (B) Example formats all containing 2 copies or 1 copy of a C-terminus sushi-domain without an IL-15 cytokine covalently bound and prefixed as "2+" or "1+" accordingly. From left to right, the 2+2 variant contains 2 copies of an anti-NKG2D binding domain; the 2+1+1 variant contains one copy of the anti-NKG2D binding domain and one copy of a second binding domain such as an anti- TAA binding domain; the 2+0 contains no antibody binding domains; the 1+0 contains no antibody binding domains. The IL-15 cytokine is then co-expressed 'in-trans' and binds the sushi domain non-covalently. Additionally presented are the modular building blocks: First the "2+ [ ] + [ ]" and the "1+ [ ] + [ ]" complexes as indicated contain one or two copies of the C-terminus sushi domain (with 2x Fabs to be added at the N- terminus). Second, the "2+1+ [ ]" and "1+1 [ ]" complexes as indicated contain one or two copies of the C- terminus sushi domain, one copy of the anti-NKG2D domain, with one second binding domain such as an anti- TAA binding Vh / VI domain to be added where indicated. (C) Four and Six polypeptide 2+2 formats. Left-hand highlights a 2+2 format comprising 2 x sushi-IL15 domains and 2 x anti-NKG2D domains comprising 4 polypeptides. Right-hand highlights 2+2 format comprising 2 x sushi-IL15 domains and 2 x anti-NKG2D comprising 6 polypeptides wherein the IL-15 cytokine (polypeptide 5 and 6) is supplied in trans (ie. from a separate expression cassette) (D) Four and Six polypeptide 2+1+1 formats. Also indicated are charge complimentarily knob-hole CH3 pairs to favour correct polypeptides 1+3 heterodimerisation alongside light chain A / A' and B / B' CH1 / CL pairings to favour correct anti-NKG2D Vh / VI (polypeptide 1 and 2) and anti-TAA Vh / VI (polypeptide 3+4) pairings respectively. Left-hand highlights a 2+1+1 format comprising 2 x sushi-l L15 domains, 1 x anti-NKG2D and 1 x anti-TAA comprising 4 polypeptides. Right-hand highlights a 2+1+1 format comprising 2 x sushi-l L15 domains, 1 x anti-NKG2D and 1 x anti-TAA comprising 6 polypeptides wherein the IL- 15 cytokine (polypeptide 5 and 6) is supplied in trans (ie. from a separate expression cassette).

[0032] Figure 2: Anti-NKG2D antibody agonism rank-ordering with CD8 T-cells (A) Example flow gating strategy and flow profiles + / - an anti-NKG2D antibody in the NKG2D agonism screening assay on CD8 T-cells. Upper frame provides an example pre-gating strategy employed to identify live CD8 cells. Bottom plots provide example results for a single anti-NKG2D (21F2) antibody after 6 days in culture. Left hand lower plot is an example CTV staining; note the increased numbers of peaks when the anti-NKG2D antibody is included (lower signal peaks represent increasing CD8 cell divisions). Middle lower plot - example FITC channel staining for Granzyme B levels. Note the increased levels of Granzyme B when the anti-NKG2D antibody is included; Right-hand lower plot - CD122 (IL-15 beta receptor) expression levels, note the increased levels of surface CD122 when anti- NKG2D antibodies are added (B) Anti-NKG2D antibody agonism rank ordering by cell proliferation induction in CD8 T-cells after 6 days incubation of + / - anti-NKG2D antibody as indicated (C) Anti-NKG2D antibody agonism rank ordering by Granzyme B induction in CD8 T-cells after 6 days incubation of + / - anti-NKG2D antibody as indicated (D) Anti-NKG2D antibody agonism rank ordering by CD122 induction levels in CD8 T-cells after 6 days incubation of + / - anti-NKG2D antibody as indicated (E) Colabfold model of most active anti-NKG2D (21F2) binding domain identified by this screening method indicating side-on engagement of target NKG2D extracellular domain (ECD) as indicated - 21F2 CDR3-led "side on" engagement of NKG2D is circled.

[0033] Figure 3: Comparison of Longer Linker 1 versus Longer Linker 2 variants of CYTB05: (A) A summary of the molecules studied including CYTB72 (a variant of CYTB05 but with an extended Linker 1 (extra Gly / Ser underlined)) and CYTB73 (a variant of CYTB05 but with an extended Linker 1 and Linker 2 (extra Gly / ser underlined) (B) Comparison of peak profile after protein A elution by preparative SEC (C) Comparison of SEC polished peak 1 and peak 2 for CYTB72 and CYTB73 as non-reduced and reduced (suffixed "r") SDS-PAGE as indicated. (D) Summary of both LC-MS and SEC-MALS based approaches to measuring observed mass(es) of the purified peaks.

[0034] Figure 4: 2+2 formatting; impact of linker design on homogeneity, recovered yield, and function. (A) Schematic of a 2+2 molecule and positioning of Linker 1 and Linker 2. As indicated, Linker 1 separates Fc region CH3 domain from CD215 sushi domain. Linker 2 separates the sushi domain from the IL-15 cytokine. Table also provided to summarise the differing linker 2 sequences included in various example clones employed in the study (B) Example SEC traces of Protein A eluates. Left-hand plot is representative of a shorter Linker 2 profile. Middle-plot is representative of a longer Linker prolife. Right-hand plot representative of a molecule wherein the IL-15 cytokine is not fused to the sushi domain hence sushi-domain is C-terminus and no Linker 2 (C) SEC analysis of Protein A eluate after production in CHO; ratio of peak 1 versus peak 2 for molecules as indicated (D) Final yields after SEC polishing for molecules as indicated (E) Six-day PBMC proliferation assay. Dose-titration X / Y plot summary of immunoconjugate (molecule, concentration as indicated) versus % Ki67 positive: NK cell sub-gate (left-hand plot) with CD56 dim sub-set (middle plot) and CD56bright sub-set (right-hand plot) (F) STAT- 5 phosphorylation in CD8 and NK cells (CD56dim and CD56bright); dose-titration X / Y plot summary of immunoconjugate (molecule, concentrations as indicated) versus % phospho-STAT-5 positive (G) PBMC cytotoxicity assay. Dose-titration X / Y plot summary of immunoconjugate (molecule, concentration as indicated) versus K562 cancer cell lysis (H) Intact mass analysis of CYTB74 by LC-MS shows main species 161 Kd (theoretical size of molecule without IL-15) (left-hand plot) or SEC-MALS shows ~100% of species sized at approx. 192 Kd indicating all species are monomeric and all contain 2 x IL-15 (Right-hand plot) (I) Functional comparison of the CYTB05 immunoconjugate (IL-15 cytokine domain fused to the C-terminus) with CYTB74 (an IL-15 cytokine supplied in trans, not fused, sushi positioned at C-terminus) with NK (CD56 dim or bright as indicated) and CD8 cells. X / Y plots showing induced response versus molecule cone. Top row - phospho Stat 5 induction, Bottom row - Ki67 induction.

[0035] Figure 5: Functional comparison of molecules with or without Fc modifications to reduce FcR binding. Bar chart summaries of NK cell FcR (CD16) +ve (left) or CD8 cell (right) activation profiles as indicated. Top rows present the comparison of phosphostat5 induction profiles for molecules without (CYTB05) or with (CYTB09) additional Fc modification to reduce FcR binding. Bottom rows present the comparison of ki67 proliferation induction profiles for molecules without (CYTB05) or with (CYTB09) additional Fc modification.

[0036] Figure 6: 2+1+1 formatting trial Series 1 - wherein all formats include original CYTB05 sushi-l L5 cassette and associated Linker 1 / Linker 2 length. (A) Summary of 2+1+1 formatting via 'FORCE' methodology to drive heterodimerization via in-vitro redox reaction to avoid additional mutagenesis of Fc domain and light chains (KiH, Crossmab etc.). Schematic of desired molecule (CYTB54, left-hand) and summary of results after production (right-hand) are shown (B) Summary of 2+1+1 formatting with 'simpler' 2-chain formatting, use of single domain VHH binding domains and Fc KiH. Schematic of desired molecule (CYTB58, left-hand) and summary of results after production (right-hand) are shown (C) Summary of 2+1+1 formatting with alternative 2-chain formatting and use of C-terminal scFV binding domains, N-terminal sushi-l L15, and KiH. Schematic of desired molecule (CYTB59, left-hand) and summary of results after production (right-hand) are shown (D) Summary of 2+1+1 formatting with alternative 2-chain formatted 'anti-parallel' design with VHH binding domains and KiH Fc. Schematic of desired molecule (CYTB60, left-hand) and summary of results after production (right-hand) are shown

[0037] Figure 7: 2+1+1 formatting trial Series 2. (Longer Linker 2, left hand) comparisons with Trial Series 3 (C-terminus sushi, IL-15 supplied in trans, right-hand). Additionally, 2+2+2 and Comparator Studies also included. Each example presents a schematic of the molecule alongside its associated Protein-A eluate profile after CHO production inclusive of background (greyed) molecule size guides as indicated (A) Head-to-head comparison of 2+1+1 KiH formatting with Longer Linker 2 (CYTB76, Left-hand) versus equivalent molecule wherein IL-15 is removed from C-terminus and supplied 'in trans' to the now C-terminus positioned sushi-domain (CYTB77, right-hand). (B) Head-to-head comparison of 2+1+1 KiH format and inclusive of a 'crossmab' anti-NKG2D binding domain formatted with Longer Linker 2 (CYTB83, left-hand) versus equivalent molecule wherein IL-15 is removed from C-terminus and supplied 'in trans' to the now C-terminus positioned sushi-domain (CYTB84, right-hand). (C) Head-to-head comparison of 2+1+1 KiH format and inclusive of a 'charge steering' anti-NKG2D binding domain formatted with Longer Linker 2 (CYTB87, left-hand) versus equivalent molecule wherein IL-15 is removed from C-terminus and supplied 'in trans' to the now C-terminus positioned sushi-domain (CYTB88, right-hand). (D) Head-to-head comparison of 2+2+2 format as indicated with Longer Linker 2 (CYTB90, lefthand) versus equivalent molecule wherein IL-15 is removed from C-terminus and supplied 'in trans' to the now C-terminus positioned sushi-domain (CYTB91, right-hand). (E) Head-to-head comparison of 2+2+2 format as indicated with Longer Linker 2 (CYTB93, left-hand) versus equivalent molecule wherein IL-15 is removed from C-terminus and supplied 'in trans' to the now C-terminus positioned sushi-domain (CYTB94, right-hand). (F) Head-to-head comparison of 2+2+2 format as indicated with Longer Linker 2 (CYTB96, left-hand) versus equivalent molecule wherein IL-15 is removed from C-terminus and supplied 'in trans' to the now C-terminus positioned sushi-domain (CYTB97, right-hand). (G) Profile of a 2+2+2 in-house comparator molecule with format as indicated inclusive of a sushi-l L15 positioned at the N-terminus (CYTB113) (H) Profile of a 2+2+2 comparator molecule as indicated with sushi-l L15 domain positioned at the N-terminus (CYTB107) (I) Profile of a 1+2+2 in-house comparator molecule with KIH as indicated and with sushi-IL15 positioned within the Fc domain C-terminal of the hinge (CYTB108).

[0038] Figure 8: Formatting Profile Summary. Comparison of Longer Linker 2 vs C-terminus sushi formatting; main peak monomer content (left-hand graph) and recovered yields (right-hand graph) after 1-step Protein A purification - also see prior Figure 7 for further details.

[0039] Figure 9: Anti-NKG2D / IL15sushi 2+2 example molecule (CYTB05) competes with MICA / B for NKG2D binding. Figures shows binding of excess (60nM) soluble MICA and MICB to immobilised NKG2D in the presence and absence of 0.2nM anti-NKG2D / IL15 (CYTB05 containing anti-NKG2D clone 21F2) as measured by ELISA. Binding normalised to IgG control.

[0040] Figure 10: Example Immunoconjugates and methods to make them. (A) Longer Linker 2 variants - guidance on positioning and length of Linker 2 for improved product yield / profiles when placed between the sushi domains and IL-15 cytokines positioned at the C-terminus of immunoconjugates as provided herein. (B) Summary of C-terminus sushi variants; Sushi domain positioned at C-terminus of heavy chain, IL-15 cytokines supplied 'in trans' and encoded by a separate ORF from a separate expression cassette. (C) Example three ORF / expression cassette approach to generate sushi-C-terminus immunoconjugates; top DNA sequence encodes kappa constant light chain - DNA encoding a N-terminal leader sequence and light chain variable domain of interest can be inserted in-frame upstream (5') of this DNA to create an ORF encoding full length antibody light chain. This ORF can be placed into a first expression cassette. Middle DNA sequence encodes a human IgGl CH3 domain fused to a sushi domain at the C-terminus. DNA encoding an N-terminal leader sequence, heavy chain variable domain, and constant domain through to and inclusive of CH2 of interest, can be inserted in-frame upstream (5') of this sequence to create a ORF encoding an antibody heavy-chain with a C-terminus sushi domain. This ORF can be inserted into a second expression cassette. Lower DNA sequence encodes a full-length IL-15. The sequence is combined with DNA encoding an N-terminal leader sequence. This ORF can be inserted into a third expression cassette. (D) Example of three expression cassette approach to generate a immunoconjugate as described herein containing a C-terminus sushi-domain and an IL-15 cytokine supplied in trans. Step 1; co-transfect the three expression cassettes containing the three ORFs encoding the three polypeptides as indicated into a cell or cells. Step 2; ORFs are translated in the cell into polypeptide component parts; these are then secreted to form the desired complex. Step 3; this complex is then purified (optionally by Protein A chromatography) to generate the final symmetrical 2+2 immunoconjugate. (E) An alternate to (D) wherein two heavy chain expression cassettes both encoding sushi domains at their C-terminus are employed with CH3 variant paired knob or hole CH3 mutations. In this instance the resulting purified immunoconjugate antibody generated contains asymmetry due to the differing but complimentary CH3 domains employed to generate the heavy chain KiH heterodimer containing sushi domains at the C-terminus. (F) A variant of (E) wherein only one of the two paired KiH heavy chain ORFs encodes a sushi- domain at the C- terminus. The resulting asymmetrical molecule generated now only contains a single sushi-domain resulting in 1+2 format. (G) This is a variant wherein the ORF encoding a polypeptide containing the CH3 domain and sushi domain at its C-terminus does not encode a heavy chain variable domain. Given no variable heavy chain, no light chain ORF is required either. This results in a 2+0 format comprising Fc domains with sushi domains at the C-terminus but no antibody binding domains (H) Similar to (G) but resulting in a 1+1 format given the use of paired KiH heavy chains and only one (the Knob variant) containing a sushi domain at the C-terminus. (I) The mirror of (H) and also generating a 1+0 variant but where the hole variant contains a sushi domain at the C- terminus.

[0041] Figure 11: Conditional immunoconjugate TAA targeting. (A) The targeting concept; a schematic example of the tumour microenvironment "TME" zone (greyed) targeted by the conditional immunoconjugate - a zone where cells positive for all 3 targets (NKG2D, CD122, TAA such as HER2) are proximal resulting in optimal agonistic effects by the immunoconjugate (B) Example preferred anti-TAA formats (C) SEQ ID and guidance for making preferred anti-TAA formats. (C) SEQ ID and guidance for preferred anti-TAA formats (D+E) Further guidance outlining modular design of this format how to insert anti-TAA Vh / VI such as anti-HER2 Vh / VI into the preferred format to create the molecules as outlined.

[0042] Figure 12: Comparison of exemplar immunoconjugates versus alternative formatted variants (A) Summary of key variant formats in this comparison highlighting the differing positions of the anti-NKG2D and sushi-l L15 (si L15) components (B) Comparative harvest yields generated in transient CHO using standard protocols (C) Monomer content of materials after one-step protein A purification (D) Monomer purity analysis after second- step preparative SEC material polishing (E) Binding to targets as indicated by standard SPR antigen binding analysis (F) Comparative agonism profiles in a IL-15 bioassay (G) Comparative agonistic effects conferred on primary human PBMCs sub-gates as indicated (NK cells left; gamma delta T-cells centre; CD8 T-cells right) (H) Conferred cytotoxicity effects in cancer cell killing studies - including health of effector cells (left hand bar chart) and killing of target cancer cells (right hand bar chart). Schematic of the exemplar CYTB84 showing engagement of NKG2D, CD122, and TAA positive cells also shown (centre) (I) Example statement of need for engagers with superior efficacy (taken from Daiichi Sankyo Limited, Japan website 28th July 2025).

[0043] Figure 13: Comparison of immunoconjugates comprising either one or two sushi-IL15 moieties. From left to right (i) bar chart showing superior SEC-HPLC monomer purity profile after one-step protein A purification for an immunoconjugate comprising two sushi-l L15 moieties (Y axis - % monomer content) (ii) bar chart summary of final recovered yields showing superior yields (Y axis - total mgs recovered) after same-scale, expression, two-step purification and formulation for a molecule comprising two sushi-l L15 moieties (iii) SEC-HPLC traces showing superior intact monomer profile (>99%) for a molecule comprising two sushi-l L15 moieties.

[0044] Figure 14: An example library of immunoconjugates incorporating the discoveries as disclosed herein. Respectively shown are immunoconjugate variants of Trastuzumab (anti-HER2), Panitumumab (anti-EGFR), Depatuxizumab (anti-EGFR viii), Nivatrotamab (anti-GD2), Atezolizumab (anti-PDLl), Coltuximab (anti-CD19), Ofatumumab (anti-CD20), Codrituzuma (anti-GPC3) (A) Outline of VH and VL sequences to be combined with the example 'core' sequences as indicated (B) Resulting library of immunoconjugates thereby created.

[0045] DETAILED DESCRIPTION OF THE INVENTION Definitions

[0046] Terms are used herein as generally used in the art, unless otherwise defined in the following.

[0047] The singular terms "a," "an," and "the" include plural referents unless context clearly indicates otherwise.

[0048] The term "immunoconjugate" as used herein refers to an antibody format (meaning all or part of an antibody) which is joined to a second molecule. The second molecule may be a cytokine and / or cytokine receptor, a radioactive agent, a cytotoxin, an interferon, a target or reporter moiety, an enzyme, a toxin, a peptide or protein, a therapeutic agent or a chemotherapeutic agent. When the second molecule includes a cytokine the immunoconjugate can also be known interchangeably as an "immunocytokine". Other examples of immunoconjugates include antibody drug conjugates and antibody-toxin fusion proteins. The antibody format may be any of those described herein.

[0049] The term "fragment" as used herein in the context of a peptide or polypeptide, refers to a peptide or polypeptide that comprises less than the full length amino acid sequence. Such a fragment may arise, for example, from a truncation at the amino terminus, a truncation at the carboxy terminus, and / or an internal deletion of a residue(s) from the amino acid sequence. Fragments may, for example, result from alternative RNA splicing or from in vivo protease activity. The term "functional fragment" refers to a peptide or polypeptide that comprises less than the full length amino acid sequence but retains the functional activity of the full length amino acid sequence from which the fragment is derived (for example the binding profile, the KD, or the agonistic properties).

[0050] The term "antigen" as used herein refers to any substance that has antigenic or immunogenic activity in an animal, preferably a mammal, and most preferably in a human, that is capable of evoking an immune response. Antigens may also be referred to as "immunogens".

[0051] The term "epitope" as used herein refers to a localised region of the antigen or target which is specifically bound by the antibody or antigen-binding fragment thereof. Epitopes usually consist of chemically active surface groupings of molecules such as amino acids or sugar side chains and have specific three dimensional structural characteristics as well as specific charge characteristics. Epitopes found on protein targets may be defined as "linear epitopes" or "conformational epitopes". Linear epitopes are formed by a continuous sequence of amino acids in a protein antigen. Conformational epitopes are formed of amino acids that are discontinuous in the protein sequence, but which are brought together upon folding of the protein into its three-dimensional structure. Epitopes may also be referred to as "antigenic determinants". An antibody binds "essentially the same epitope" as another antibody when they both recognize identical or sterically overlapping epitopes. Commonly used methods to determine whether two antibodies bind to identical or overlapping epitopes are competition assays, which can be configured in a number of different formats (e.g. well plates using radioactive or enzyme labels, or flow cytometry on antigen-expressing cells) using either labelled antigen or labelled antibody. An antibody binds "the same epitope" as another antibody when they both recognize identical epitopes (i.e. all contact points between the antigen and the antibody are the same).

[0052] The term "covalently linked" as used here (also referred to as "covalently bound", "covalently joined" or "covalently attached" refers to multiple molecules being chemically joined together by a covalent bond which involves the forming of electron pairs between the molecules by sharing of electrons. For example, two peptides that are fused together via a peptide bond are covalently linked.

[0053] The term "non-covalently linked" as used here (also referred to as "non-covalently bound", "non-covalently joined" or "non-covalently attached" refers to multiple molecules being joined together without the sharing of electrons. Non-covalent bonds generally involve electromagnetic interactions between molecules including but not limited to ionic bonds, hydrophobic effects, hydrogen bonding, van der Waals forces, and electrostatic interactions. For example, a ligand and receptor are usually bound together by non-covalent linkage.

[0054] The term "directly fused" as used herein refers to multiple naturally non-contiguous polypeptides being physically or chemically joined together without an intermediate joining moiety, such as an additional linker that is disparately sourced or designed. This includes the molecules being covalently bound or linked together, without a disparate linker. This can refer to fusions created through the joining of two or more genes or gene fragments that originally coded for separate (ie naturally non-contiguous) proteins or peptides into a single open reading frame which is then expressed and translated as a single contiguous polypeptide without an intermediate disparate linker,

[0055] The term "about" as used herein includes up to and including 10% greater and up to and including 10% lower than the value specified, suitably up to and including 5% greater and up to and including 5% lower than the value specified, especially the value specified. The term "between", includes the values of the specified boundaries. The term "agonist" as used herein refers to a substance that binds to a target receptor and change the receptor activity to produce a response, e.g. activate the receptor. Agonists therefore have both affinity and intrinsic efficacy. An "agonistic antibody" or "agonistic immunoconjugate" will therefore bind to a receptor and cause the same action as the substance that normally binds to the receptor. An "inverse agonist" is one which binds to a receptor and causes the opposite action as the substance that normally binds to the receptor e.g. reduces receptor activity.

[0056] The term "antagonist" as used herein refers to a substance that binds to a target receptor but does not produce a response, e.g. blocks the receptor but does not activate it. Antagonists therefore have affinity but not intrinsic efficacy. An "antagonistic antibody" or "antagonistic immunoconjugate" will therefore bind to a receptor and by virtue of occupying a fraction of the receptor population, reduces the probability of occupancy by an agonist. Such antibodies or immunoconjugates are therefore referred to as "blocking antibodies" or "blocking immunoconjugates".

[0057] The term "immunostimulant" or "immunostimulators" are substances that promote the activation of immune system components or cells, therefore stimulating the immune system into producing or increasing an immune response. Immunostimulants may be specific, for example an antigen or vaccine, or may be non-specific and operate without antigen specificity, for example an adjuvant. An "immune response" is a measurable change in at least one cell, or one cell-type, or one endocrine pathway, or one exocrine pathway, of the immune system (including but not limited to a cell-mediated response, a humoral response, a cytokine response, a chemokine response), for example upon addition of a modulating immunocytokine.

[0058] The term "immune cell" as used herein, refers to a cell of the immune system including, but not limited to, CD34+ cells, B-Cells, CD45+ (lymphocyte common antigen) cells, Alpha-Beta T-cells, Cytotoxic T-cells, Helper T- cells, Plasma Cells, Neutrophils, Monocytes, Macrophages, Red Blood Cells, Platelets, Dendritic Cells, Phagocytes, Granulocytes, Innate lymphoid cells, Natural Killer (NK) cells and Gamma Delta T-cells. Typically, immune cells are classified with the aid of combinatorial cell surface molecule analysis (e.g., via flow cytometry) to identify or group or cluster to differentiate immune cells into sub-populations.

[0059] The term "subject" or "patient" refers to any animal, including, but not limited to, mammals such as humans.

[0060] The term "composition" as used herein, is intended to encompass a product containing the specified ingredients (e.g. an immunoconjugate of the invention) in, optionally, the specified amounts, as well as any product which results, directly or indirectly, from combination of the specified ingredients in, optionally, the specified amounts.

[0061] The term "cancer," as used herein, refers to the abnormal growth or division of cells. Cancers may be benign, pre-malignant or malignant. Generally, the growth and / or life span of a cancer cell exceeds, and is not coordinated with, that of the normal cells and tissues around it. Cancer occurs in a variety of cells and tissues, including the oral cavity (e.g., mouth, tongue, pharynx, etc.), digestive system (e.g., oesophagus, stomach, small intestine, colon, rectum, liver, bile duct, gall bladder, pancreas, etc.), respiratory system (e.g., larynx, lung, bronchus, etc.), bones, joints, skin (e.g., basal cell, squamous cell, meningioma, etc.), breast, genital system, (e.g., uterus, ovary, prostate, testis, etc.), urinary system (e.g., bladder, kidney, ureter, etc.), eye, nervous system (e.g., brain, etc.), endocrine system (e.g., thyroid, etc.), and hematopoietic system (e.g., lymphoma, myeloma, leukaemia, acute lymphocytic leukaemia, chronic lymphocytic leukaemia, acute myeloid leukaemia, chronic myeloid leukaemia, etc.).

[0062] The term "host" as used herein refers to an animal, preferably a mammal, and most preferably a human.

[0063] The term "host cell" or "recombinant host cell" as used herein refers to the particular subject cell transfected with a (recombinant) nucleic acid molecule and the progeny or potential progeny of such a cell. Progeny of such a cell may not be identical to the parent cell transfected with the nucleic acid molecule due to mutations or environmental influences that may occur in succeeding generations or integration of the nucleic acid molecule into the host cell genome. For example, a Chinese hamster ovary (CHO) cell, which is an epithelial cell line derived from the ovary of the Chinese hamster, may be used as a host cell.

[0064] The term "effective amount" refers to an amount of an immunocytokine or composition or pharmaceutical composition containing said immunocytokine that is effective, at dosages and for periods of time necessary, to achieve the desired effect, including a therapeutic or prophylactic result. For example the term could refer to the amount of an immunocytokine of the invention to achieve a specified result (e.g. an agonistic effect).

[0065] The term "therapeutically effective amount" refers to the minimum concentration of an immunocytokine or composition or pharmaceutical composition containing said immunocytokine required to effect a measurable improvement or prevention of a particular disease or disorder. A therapeutically effective amount herein may vary according to factors such as the disease state, age, sex, and weight of the patient, and the ability of the immunocytokine to elicit a desired response in the individual. A therapeutically effective amount is also one in which toxic or detrimental effects of the antibody are outweighed by the therapeutically beneficial effects.

[0066] The term "affinity" as used herein is a measure of the binding strength between an antigen and an antigenbinding site on the antibody (or antigen-binding fragment thereof). Affinity is represented by the equilibrium constant for the dissociation of an antigen with an antigen-binding polypeptide (KD). The lower the KD value, the stronger the binding strength between an antigen and the antigen-binding site. Alternatively, the affinity can also be expressed as the affinity constant (KA), which is 1 / KD. Any KD value less than 10-6 is considered to indicate binding. Affinity can be determined by known methods, depending on the specific antigen of interest. For example. KD may be determined by surface plasmon resonance. KD may also be determined by Scatchard analysis and / or competitive binding assays, such as radioimmunoassays (RIA), enzyme immunoassays (EIA) and sandwich competition assays, equilibrium dialysis, equilibrium binding, gel filtration, ELISA, or spectroscopy (e.g. using a fluorescence assay) and the different variants thereof known in the art. The binding affinity of the immunoconjugate or fragment thereof may be established by coating the immunoconjugate or fragment thereof directly or indirectly (e.g. by capture with an anti-human IgG Fc) onto a sensor surface (e.g. an amine high capacity chip or equivalent), wherein the target bound by the immunoconjugate or fragment thereof (e.g. NKG2D or IL-15RP) is flowed over the sensor surface to detect binding. Suitably, a MASS-2 instrument (which may also be referred to as Sierra SPR-32) is used at 25-C in PBS + 0.02 % Tween 20 running buffer at 30 pl / min.

[0067] The term "avidity" as used herein is the measure of the strength of binding between an antibody, or antigenbinding fragment thereof, and the antigen. Avidity is related to both the affinity between an antigen and its antigen-binding site on the antibody and the number of binding sites for that antigen present on the antibody.

[0068] The term "NKG2D" refers to the NKG2D homodimeric receptor (natural killer group 2, member D receptor) which is a membrane-bound receptor expressed on a variety of cells including NK cells and y6 T cells. It is a member of the NKG2 (CD94) class of receptors. Further details can be found in PCT / EP2024 / 053368.

[0069] The term "NKp30" refers to a member of the NCR (Natural Cytotoxicity Receptors) class of receptors. It is also known as natural cytotoxicity receptor 3 (NCR3) and CD337. The term "NKp44" refers to another member of the NCR family expressed on gamma delta T cells and NK cells, also also known as natural cytotoxicity receptor 2 (NCR2) and CD336. The term "NKp46" also refers to another member of the NCR class of receptors expressed on gamma delta T-cells and NK cells and is also known as natural cytotoxicity receptor 1 (NCR1) and CD335. The term "DNAM-1" refers to a 65 kDa transmembrane glycoprotein containing two immunoglobulin-like domains expressed on NK and Gamma Delta T-cells (also known as CD226).

[0070] Other terms are defined herein within the description of the various aspects of the invention.

[0071] Immunoconjugates

[0072] Provided herein are immunoconjugates comprising (a) a multivalent antibody or antigen-binding fragment thereof comprising (i) at least two antibody binding domains wherein the first antibody binding domain specifically binds to a first target antigen selected from the group consisting of NKG2D, NKp30, NKp46, NKp44 and DNAM-1; and the second antibody binding domain specifically binds to a second, different target antigen; and (ii) a human immunoglobulin Fc domain comprising a first chain comprising in an N- to C- terminal direction a CH2 domain and a CH3 domain; and a second chain comprising in an N- to C- terminal direction a CH2 domain and a CH3 domain; and (b) at least one IL-15 receptor alpha (CD215) or a functional fragment thereof covalently linked to at least one C-terminus of the Fc domain.

[0073] Arrangement and design of immunoconjugates of the invention

[0074] The two components of the immunoconjugates of the invention are the multivalent antibody or antigenbinding fragments thereof and the IL-15 component (which comprises at least one IL-15 receptor alpha (CD215) or a functional fragment thereof and may optionally further comprise an IL-15 cytokine).

[0075] The multivalent antibody or antigen-binding fragment thereof may comprise at least two (preferably exactly two) immunoglobulin heavy chains and at least two (preferably exactly two) immunoglobulin light chains.

[0076] The multivalent antibody or antigen-binding fragment thereof comprises at least two antibody binding domains. The first antibody binding domain specifically binds to a first target antigen selected from the group consisting of NKG2D, NKp30, NKp46, NKp44 and DNAM-1. Preferably, the first antibody binding domain specifically binds to a first target antigen which is NKG2D. The second antibody binding domain specifically binds to a second, different target antigen. Preferably the second target antigen is a TAA. The TAA may be selected from the group consisting of HER2, EGFR, CD19 and CD20. Preferably, the second antibody binding domain specifically binds to a second target antigen which is HER2. The second target antigen is not the same as the first target antigen. The first and second antibody binding domains may be on different chains. The first antibody binding domain may comprise one immunoglobulin heavy chain and one immunoglobulin light chain and the second antibody binding domain may comprise one, different, immunoglobulin heavy chain and one, different, immunoglobulin light chain.

[0077] As used herein, the terms "N-terminal" and "C-terminal" with respect to peptides, polypeptides or proteins have their normal meaning in the art. The N-terminus (also known as N-term, amino-terminus, amine terminus or NHz-terminus) refers to the start of a protein or polypeptide chain (the N refers to the free amide group at the start of the chain). The C-terminus (also known as C-term, caboxy-terminus, carboxyl-terminus or COOH- terminus) refers to the end of a protein or polypeptide chain (the C refers to the free carboxylic group at the end of the chain). If one component is referred to as being "N-terminal" to a second component, this means that, within the polypeptide chain, the first component is positioned closer to the N-terminus than the second component is. If one component is referred to as being "C-terminal" to a second component, this means that, within the polypeptide chain, the first component is positioned closer to the C-terminus than the second component is. If one component is referred to as being at the "N-terminus" of a polypeptide chain, this refers to the component being the first component in the chain, since there is only one N-terminus in each polypeptide chain. If one component is referred to as being at the "C-terminus" of a polypeptide chain, this refers to the component being the last component in the chain, since there is only one C-terminus in each polypeptide chain. Translation of a protein from messenger RNA occurs in an N- to C-terminal direction.

[0078] The multivalent antibody or antigen-binding fragment thereof comprises a human immunoglobulin Fc domain or fragment thereof. The Fc domain comprises two chains which may be the same or may be different. The first chain comprises, in an N- to C- terminal direction, a CH2 domain and a CH3 domain. The second chain comprises, in an N- to C- terminal direction a CH2 domain and a CH3 domain. The multivalent antibody or antigen-binding fragment thereof may further comprise a CHl-hinge domain. The first chain may comprise, in an N- to C- terminal direction, a CHI domain, a hinge domain, a CH2 domain and a CH3 domain. The second chain may comprise, in an N- to C- terminal direction a CHI domain, a hinge domain, a CH2 domain and a CH3 domain. The IL-15 receptor alpha (CD215) or a functional fragment thereof is covalently linked to the C- terminus of the Fc domain, optionally via a linker. When only one IL-15 receptor alpha (CD215) or a functional fragment thereof is present the IL-15 receptor alpha (CD215) or a functional fragment thereof is covalently linked to the C-terminus of the first chain of the Fc domain or the C-terminus of the second chain of the Fc domain, optionally via a linker. When two IL- 15 receptor alpha (CD215) or functional fragments thereof are present a first IL-15 receptor alpha (CD215) or a functional fragment thereof is covalently linked to the C- terminus of the first chain of the Fc domain optionally via a linker and a second IL-15 receptor alpha (CD215) or a functional fragment thereof is covalently linked to the C-terminus of the second chain of the Fc domain optionally via a linker.

[0079] The structure and sequence of the multivalent antibody or antigen-binding fragment thereof is dealt with in more detail below.

[0080] The linker that may join the IL-15 receptor alpha (CD215) or a functional fragment thereof to the multivalent antibody or antigen-binding fragment thereof (specifically the C-terminus of the Fc domain) may be known as "linker 1" and is described elsewhere herein.

[0081] The two antibody binding domains are N-terminal to the Fc domain and the IL-15 receptor alpha (CD215) or a functional fragment thereof is C-terminal to the Fc domain, such that the antibody binding domains and the IL- 15 receptor alpha (CD215) or a functional fragment thereof are separated from each other by the Fc domain.

[0082] In some embodiments, the immunoconjugate does not comprise a covalently linked IL-15 cytokine and the IL- 15 receptor alpha (CD215) or a functional fragment thereof is at the C-terminus of the polypeptide chain. In such embodiments, the immunoconjugate may comprise at least one human IL-15 cytokine non-covalently bound (non-covalently associated) to the IL-15 receptor alpha (CD215) or a functional fragment thereof. In such embodiments the IL-15 cytokine and the IL-15 receptor alpha (CD215) or a functional fragment thereof are joined by their receptor-ligand binding properties, in other words the IL-15 cytokine binds to its cognate receptor (the IL-15 receptor alpha (CD215) or a functional fragment thereof). In such embodiments the IL-15 cytokine and the IL-15 receptor alpha (CD215) or a functional fragment thereof do not form part of the same polypeptide chain and the IL-15 cytokine is expressed separately and presented "in trans" to the IL-15 receptor alpha (CD215) or a functional fragment thereof. The immunoconjugate may comprise one human IL-15 cytokine or fragment thereof non-covalently bound to a first IL-15 receptor alpha (CD215) or a functional fragment thereof. The immunoconjugate may comprise a first human IL-15 cytokine or fragment thereof non-covalently bound to a first IL-15 receptor alpha (CD215) or a functional fragment thereof and a second human IL-15 cytokine or fragment thereof non-covalently bound to a second IL-15 receptor alpha (CD215) or a functional fragment thereof.

[0083] In some other embodiments, immunoconjugate further comprises a covalently linked human IL-15 cytokine. The IL-15 receptor alpha (CD215) or a functional fragment thereof and may optionally also comprise an IL-15 cytokine. The human IL-15 cytokine may be covalently linked to the C-terminus of the at least one IL-15 receptor alpha (CD215) or functional fragment thereof. In such embodiments the IL-15 cytokine and the IL-15 receptor alpha (CD 15) or a functional fragment thereof form part of the same polypeptide chain. The immunoconjugate may comprise one human IL-15 cytokine or fragment thereof covalently linked to the C-terminus of a first IL-15 receptor alpha (CD215) or a functional fragment thereof. The immunoconjugate may comprise a first human IL-15 cytokine or fragment thereof covalently linked to the C-terminus of a first IL-15 receptor alpha (CD215) or a functional fragment thereof and a second human IL-15 cytokine or fragment thereof covalently linked to the C-terminus of a second IL-15 receptor alpha (CD215) or a functional fragment thereof. The IL-15 cytokine and the IL-15 receptor alpha (CD215) or functional fragment thereof may be directly fused to each other. The IL-15 cytokine and the IL-15 receptor alpha (CD215) or functional fragment thereof may be joined via a linker.

[0084] The linker that may covalently join the N-terminus of the IL-15 cytokine to the C-terminus of IL-15 receptor alpha (CD215) or a functional fragment thereof may be known as "linker 2" and is defined elsewhere herein.

[0085] The two types of component in the immunoconjugates (the IL-15 component and the antibody component) will now be described in more detail. The arrangement and design of immunoconjugates described herein applies to each of the components now described in more detail.

[0086] Antibodies and fragments thereof

[0087] The term "antibody" as used herein refers to immunoglobulin molecules and immunologically active portions of immunoglobulin molecules, i.e., molecules that contain an antigen binding site that specifically binds an antigen, whether natural or partly or wholly synthetically produced. This includes molecules that are fusions of different antibody components, for example a IgG constant domain or a fragment thereof joined to an antigen binding domain, for example a ScFv. The term "antibody", "immunoglobulin" or "Ig" may be used interchangeably herein. The term also covers any polypeptide or protein having a binding domain which is, or is homologous to, an antibody binding domain. Antibodies may be polyclonal or monoclonal. These can be derived from natural sources, or they may be partly or wholly synthetically produced. Antibodies are polypeptides that typically contain two identical heavy chains and two identical light chains, which are smaller than the heavy chains. The immunoglobulin heavy chains are sometimes referred to herein as "a first polypeptide chain". The immunoglobulin light chains are sometimes referred to herein as "a second polypeptide chain". In mammals there are two types of light chain, which are called lambda (A) and kappa (K). Each of the heavy chains and each of the light chains are composed of a variable region and a constant region. The heavy chain variable region is referred to as the VH region and the light chain variable region is referred to as the VL region. For kappa light chains, the VL region can also be referred to as the VK region. Each of the variable regions of the heavy and light chains comprise three complementarity determining regions (CDRs), CDR1, CDR2 and CDR3. These are named VLCDR1, VLCDR2, VLCDR3, VHCDR1, VHCDR2 and VHCDR3 respectively.

[0088] The framework and complementarity determining regions have been precisely defined (Kabat et al. Sequences of Proteins of Immunological Interest, Fifth Edition U.S. Department of Health and Human Services, (1991) NIH Publication Number 91-3242). There are also alternative numbering conventions for CDR sequences, for example those set out in Chothia et al. (1989) Nature 342: 877-883 or as summarized by IMGT.org. In a conventional antibody, each VH and VL is composed of three CDRs and four FRs, arranged from amino-terminus (N-terminus) to carboxy-terminus (C-terminus) in the following order: FR1, CDR1, FR2, CDR2, FR3, CDR3, FR4. The conventional antibody tetramer of two heavy immunoglobulin chains and two light immunoglobulin chains is formed with the heavy and the light immunoglobulin chains inter-connected by e.g. disulphide bonds, and the heavy chains similarly connected. The "constant region" or "constant domain" comprises a heavy chain constant region and a light chain constant region. The heavy chain constant region includes three domains, CHI, CH2 and CH3, with a hinge between the CHI and CH2 domains. The light chain constant region is comprised of one domain, CL. The variable domain of the heavy chains and the variable domain of the light chains are binding domains that interact with an antigen. The constant regions of the antibodies typically mediate the binding of the antibody to host tissues or factors, including various cells of the immune system (e.g. effector cells) and the first component (Clq) of the classical complement system. The antibodies comprised in the immunoconjugates of the invention may be of any suitable type, including IgA, IgD, IgE, IgG, IgM and IgY, although IgG may be preferred. IgGl backbones may be most preferred.

[0089] The term "antigen binding fragment" (which may also referred to as "antibody fragment", "immunoglobulin fragment", or "antigen-binding polypeptide") as used herein refers to a portion of an antibody (or constructs that contain said portion) that specifically binds to the target (e.g. a molecule in which one or more immunoglobulin chains is not full length, but which still specifically binds to the target). Examples of binding fragments encompassed within the term antibody fragment include Fab, F(ab')2, Fv, scFv, dAb, Fd; and diabodies. A scFv (single-chain fragment variable) format is a heavy variable region of an antibody (VH) and a light variable region of an antibody (VL) fused together, usually by a flexible peptide linker. The fragment antigen-binding region ("Fab" region) is an antibody binding domain composed of a monovalent fragment consisting of the VL, VH, CL and CHI domains.

[0090] The term "crossmab" or "CL-CH1 switching" as used herein refers to modifications to multispecific antibodies wherein a heavy chain and light chain have their respective CL and CHI domains or portions thereof switched in one binding arm such to encourage correct light-chain / heavy-chain pairing and / or reduce wrong light-chain / heavy-chain pairing (also termed mispairing). Examples of this approach are further described by Schaefer, W. et al., PNAS, 108 (2011) 11187-1191 DOI: 10.1073 / pnas.l019002108

[0091] The term "charge steering" "charge switching" or "polarity swapping" as employed in "light chain charge steering" and as used herein refers to modification to multispecific antibodies where a heavy chain / light chain pair in one binding arm incorporate charge-complimentary amino acid modifications such to encourage correct light chain / heavy chain pairing and / or reduce wrong light chain / heavy chain pairing (also termed mispairing). Examples such heavy chain / light pair modifications are further described in EP2543680A1

[0092] The term "antibody binding domain" (which may also referred to as "antigen binding region," "antigen binding fragment," and similar terms) refers to that portion of an antibody which comprises the amino acid residues that interact with an antigen and confer on the binding agent its specificity and affinity for the antigen (e.g. the complementarity determining regions (CDRs)).

[0093] The term "Fc domain" or "Fc region" refers to the "fragment crystallizable region" which is a C-terminal region of an immunoglobulin heavy chain, including native- sequence Fc regions and variant Fc regions. The "Fc domain" as used herein refers to a portion of an antibody (or constructs that contain said portion) comprising the CH2 and CH3 domains. An Fc region is dimeric and comprises paired heavy chain constant regions each comprising a CH2 and CH3 domain. The "Fc fragment" refers to the carboxy-terminal portions of both H chains held together by disulfides. The effector functions of antibodies are determined by sequences in the Fc region, the region which is also recognized by Fc receptors (FcR) found on certain types of cells.

[0094] The term "Fc enabled" refers to an antibody that comprises a functional Fc region (fragment crystallizable region), i.e. a Fc region that has not been disabled by mutation or otherwise. Fc enabled of "effector enabled" antibodies demonstrate unattenuated Fc function.

[0095] The term "Fc disabled" refers to an antibody of fragment thereof that comprises a non-functional or less- functional Fc region due to mutation or otherwise. Fc disabled or "effector disabled" antibodies are not able or less able to be recognized by Fc receptors (FcR) found on certain types of cells. In a "Fc disabled" antibody or antibody component the Fc domain may comprise a substitution with respect to a wild-type Fc sequence (for example human IgGl wildtype Fc domain), wherein the substitution reduces binding of the Fc domain to an Fc receptor. Different substitutions to achieve this effect are known in the art and may be applied. The substitution

[0096] 11 may be a substitution at a position selected from the group consisting of L234, L235, G236, G237 and P329 (EU index numbering). The substitution may be a substitution selected from the group consisting of L235A and G237A (EU index numbering). Further example FcR reduced-binding benchmarks are also provided herein.

[0097] The term "effector function" as used herein is meant to refer to one or more of interactions with Fc receptors, antibody dependent cell mediated cytotoxic activity (ADCC), complement-dependent cytotoxic activity (CDC) mediated responses, Fc-mediated phagocytosis or antibody dependent cellular phagocytosis (ADCP) and antibody recycling via the FcRn receptor.

[0098] The term "monoclonal antibody" as used herein refers to an antibody obtained from a population of substantially homogeneous antibodies, i.e. the individual antibodies comprising the population are identical except for possible naturally occurring mutations and / or post-translation modifications (e.g. isomerizations, amidations) that may be present in minor amounts. Monoclonal antibodies are highly specific, and are directed against a single antigenic determinant or epitope. In contrast, polyclonal antibody preparations typically include different antibodies directed against different antigenic determinants (or epitopes). The term "monoclonal antibody" as used herein encompasses both intact and full-length monoclonal antibodies as well as antibody fragments (such as Fab, Fab', F(a b'Jz, Fv), single chain (scFv) mutants, fusion proteins comprising an antibody portion, and any other modified immunoglobulin molecule comprising an antigen recognition site.

[0099] The term "valency" as used herein refers to the number of antigen binding sites on a single antibody molecule. The antibody components of the invention are "multivalent", since they possess at least two antigen binding sites on each immunoconjugate. For example, the valency of a full human IgG antibody is 2, because it has two antigen binding sites per IgG molecule and the valency of other antibodies may be higher.

[0100] The term "multivalent" as used herein is used to describe a molecule with more than one functional binding domain for any given target. For example, a multivalent immunocytokine may have more than one functional binding domain to a cytokine receptor and more than one functional binding domain to an antigen. An antibody component is multivalent if the total number of antigen binding sites is greater than 1, regardless of whether the antibody component comprises a first antigen binding site for a first antigen and a second antigen binding site for a second different antigen, or whether the antibody component comprises two antigen binding sites for the same antigen. The term "human antibody" as used herein refers to antibodies having variable and constant regions derived from human germline immunoglobulin sequences. Human subjects administered with said human antibodies do not generate cross-species antibody responses (for example termed HAMA responses - human-anti-mouse antibody) to the primary amino acids contained within said antibodies. Said human antibodies may include amino acid residues not encoded by human germline immunoglobulin sequences (e.g. mutations introduced by random or site-specific mutagenesis or by somatic mutation), for example in the CDRs. However, the term is not intended to include antibodies in which CDR sequences derived from the germline of another mammalian species, such as a mouse, have been grafted onto human framework sequences. Human antibodies that are prepared, expressed, created or isolated by recombinant means, such as antibodies expressed using a recombinant expression vector transfected into a host cell, antibodies isolated from a recombinant, combinatorial human antibody library, antibodies isolated from an animal (e.g. a mouse) that is transgenic for human immunoglobulin genes or antibodies prepared, expressed, created or isolated by any other means that involves splicing of human immunoglobulin gene sequences to other DNA sequences, may also be referred to as "recombinant human antibodies".

[0101] Substituting at least one amino acid residue in the framework region of a non-human immunoglobulin variable domain with the corresponding residue from a human variable domain is referred to as "humanisation". Humanisation of a variable domain may reduce immunogenicity in humans.

[0102] The term "specificity" as used herein is the ability of an antibody or antibody binding domain to recognise a particular antigen as a unique molecular entity and distinguish it from another. Specificity therefore refers to the number of different types of antigens or antigenic determinants to which a particular antibody or antigenbinding fragment thereof can bind. An antibody that "specifically binds" to an antigen or an epitope is a term well understood in the art. A molecule is said to exhibit "specific binding" if it reacts more frequently, more rapidly, with greater duration and / or with greater affinity with a particular target antigen or epitope, than it does with alternative targets. An antibody "specifically binds" to a target antigen or epitope if it binds with greater affinity, avidity, more readily, and / or with greater duration than it binds to other substances. In one embodiment, the extent of binding of an antibody to an unrelated target is less than about 10% of the binding of the antibody to the target as measured, e.g. by a radioimmunoassay (RIA).

[0103] The term "monospecific antibody" as used herein refers to an antibody that only specifically binds to one antigen. Monospecific antibodies may be multivalent (have multiple binding sites for that one antigen) but if the antibody only recognises one antigen, it is still classed as a monospecific antibody. By contrast, the term "multispecific antibody" as used herein refers to an antibody that is capable of binding a plurality of different epitopes simultaneously or sequentially. Generally, the epitopes will not be on the same antigen. Hence a multispecific antibody has the capability to specifically bind to epitopes present on different antigens via a plurality of different binding domains. A "bispecific antibody" is an antibody that is capable of binding two different epitopes simultaneously and / or sequentially. Generally, the epitopes will not be on the same antigen. Hence bispecific antibodies have the capability to specifically bind to two different epitopes present on two different antigens via two different binding domains.

[0104] The terms "EU index numbering" and like terms such as "Kabat" or "Kabat numbering" are recognized in the art and refer to systems of numbering amino acid residues which are more variable (i.e. hypervariable) than other amino acid residues in the heavy chain variable regions of an antibody, or an antigen binding portion thereof. Such numbering systems are well known in the art, for example Kabat et al., (1971) Ann. NY Acad. Sci., 190:382-391 and, Kabat et al. (1991) Sequences of Proteins of Immunological Interest, Fifth Edition, U.S. Department of Health and Human Services, NIH Publication No. 91-3242.

[0105] Identity and homology

[0106] "Identity" as known in the art is the relationship between two or more polypeptide sequences or two or more polynucleotide sequences, as determined by comparing the sequences. In the art, identity also means the degree of sequence relatedness between polypeptide or polynucleotide sequences, as the case may be, as determined by the match between strings of such sequences. While there exist a number of methods to measure identity between two polypeptides or two polynucleotide sequences, methods commonly employed to determine identity are codified in computer programs. Preferred computer programs to determine identity between two sequences include, but are not limited to, GCG program package (Devereux, et al., Nucleic Acids Research, 12, 387 (1984), BLASTP, BLASTN, and FASTA (Atschul et al., J. Molec. Biol. 215, 403 (1990)).

[0107] One can use a program such as the CLUSTAL program to compare amino acid sequences. This program compares amino acid sequences and finds the optimal alignment by inserting spaces in either sequence as appropriate. It is possible to calculate amino acid identity or similarity (identity plus conservation of amino acid type) for an optimal alignment. A program like BLASTx will align the longest stretch of similar sequences and assign a value to the fit. It is thus possible to obtain a comparison where several regions of similarity are found, each having a different score. Both types of identity analysis are contemplated in the present invention. The percent identity of two amino acid sequences or of two nucleic acid sequences is determined by aligning the sequences for optimal comparison purposes (e.g., gaps can be introduced in the first sequence for best alignment with the sequence) and comparing the amino acid residues or nucleotides at corresponding positions. The "best alignment" is an alignment of two sequences which results in the highest percent identity. The percent identity is determined by the number of identical amino acid residues or nucleotides in the sequences being compared (i.e., % identity = number of identical positions / total number of positions x 100). Generally, references to % identity herein refer to % identity along the entire length of the molecule, unless the context specifies or implies otherwise.

[0108] The determination of percent identity between two sequences can be accomplished using a mathematical algorithm known to those of skill in the art. An example of a mathematical algorithm for comparing two sequences is the algorithm of Karlin and Altschul (1990) Proc. Natl. Acad. Sci. USA 87:2264-2268, modified as in Karlin and Altschul (1993) Proc. Natl. Acad. Sci. USA 90:5873-5877. The NBLAST and XBLAST programs of Altschul, et al. (1990) J. Mol. Biol. 215:403-410 have incorporated such an algorithm. BLAST nucleotide searches can be performed with the NBLAST program, score = 100, wordlength = 12 to obtain nucleotide sequences homologous to nucleic acid molecules of the invention. BLAST protein searches can be performed with the XBLAST program, score = 50, wordlength = 3 to obtain amino acid sequences homologous to protein molecules of the invention. To obtain gapped alignments for comparison purposes, Gapped BLAST can be utilised as described in Altschul et al. (1997) Nucleic Acids Res. 25:3389-3402. Alternatively, PSI-Blast can be used to perform an iterated search which detects distant relationships between molecules (Id.). When utilising BLAST, Gapped BLAST, and PSI-Blast programs, the default parameters of the respective programs (e.g., XBLAST and NBLAST) can be used. See http: / / www.ncbi.nlm.nih.gov. Another example of a mathematical algorithm utilised for the comparison of sequences is the algorithm of Myers and Miller, CABIOS (1989). The ALIGN program (version 2.0) which is part of the CGC sequence alignment software package has incorporated such an algorithm. Other algorithms for sequence analysis known in the art include ADVANCE and ADAM as described in Torellis and Robotti (1994) Comput. Appl. Biosci., 10 :3-5; and FASTA described in Pearson and Lipman (1988) Proc. Natl. Acad. Sci. 85:2444-8. Within FASTA, ktup is a control option that sets the sensitivity and speed of the search.

[0109] Typically, the amino acid sequence of the VH and VL regions of the immunocytokines provided in the invention have at least 90% identity, for example using the default parameters of the BLAST computer program (Atschul et al., J. Mol. Biol. 215, 403-410 (1990)) provided by HGMP (Human Genome Mapping Project), at the amino acid level, to the amino acid sequences of the VH and VL regions described below. More typically, the VH and VL regions have at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or at least 99% identity, at the amino acid level, to the sequences shown below. Typically, each of the VH and VL regions of the immunocytokines used in the invention has this level of identity to the amino acid sequences of the VH and VL regions set out below. Alternatively, only one of the VH and VL regions of the immunocytokines used in the invention has this level of identity to the amino acid sequences of the VH and VL regions set out below.

[0110] Typically, the amino acid sequence of the CDR regions of the immunocytokines provided in the invention have at least 95% identity, for example using the default parameters of the BLAST computer program (Atschul et al., J. Mol. Biol. 215, 403-410 (1990)) provided by HGMP (Human Genome Mapping Project), at the amino acid level, to the amino acid sequences of the CDR regions described below. More typically, the CDR regions have at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or at least 99% identity, at the amino acid level, to the sequences shown below. Typically, each of the CDR regions of the immunocytokines used in the invention has this level of identity to the amino acid sequences of the CDR regions set out below. Alternatively, only one of the CDR regions of the immunocytokines used in the invention has this level of identity to the amino acid sequences of the CDR regions set out below.

[0111] Identity, as used herein, may be used interchangeably with "homology" and "similarity". References to particular % identities apply equally to % homology and % similarity. Homology and similarity may be determined using appropriate algorithms, such as FASTA, BLAST and Gapped BLAST. Software for performing these analyses are publicly available.

[0112] Variants and Conservative Substitutions

[0113] As used herein the term "variant" relates to proteins that have a similar amino acid sequence and / or that retain the same function. For instance, the term "variant" encompasses proteins or polypeptides which include one or more amino acid additions, deletions, substitutions or the like. An example of a variant of the present invention is a protein comprising a peptide as defined below, apart from the substitution of one or more amino acids with one or more other amino acids. Amino acid substitutions may be made to, for example, reduce or eliminate liabilities in the amino acid sequences. Alternatively, amino acid substitutions may be made to improve antigen affinity or to humanise or deimmunise the antibodies, if required. Affinity matured variants, humanised variants and deimmunised variants of the specified antibodies are provided herein, as well as variants comprising amino acid substitutions to reduce or eliminate any liabilities in the sequences of the antibodies. The skilled person is aware that various amino acids have similar properties. One or more such amino acids of a substance can often be substituted by one or more other such amino acids without eliminating a desired activity of that substance.

[0114] Thus, the amino acids glycine, alanine, valine, leucine and isoleucine can often be substituted for one another (amino acids having aliphatic side chains). Of these possible substitutions it is preferred that glycine and alanine are used to substitute for one another (since they have relatively short side chains) and that valine, leucine and isoleucine are used to substitute for one another (since they have larger aliphatic side chains which are hydrophobic). Other amino acids which can often be substituted for one another include: phenylalanine, tyrosine and tryptophan (amino acids having aromatic side chains); lysine, arginine and histidine (amino acids having basic side chains); aspartate and glutamate (amino acids having acidic side chains); asparagine and glutamine (amino acids having amide side chains); and cysteine and methionine (amino acids having sulphur containing side chains).

[0115] Substitutions of this nature are often referred to as "conservative" or "semi- conservative" amino acid substitutions.

[0116] Using the three letter and one letter codes the naturally occurring amino acids may be referred to as follows: glycine (G or Gly), alanine (A or Ala), valine (V or Vai), leucine (L or Leu), isoleucine (I or lie), proline (P or Pro), phenylalanine (F or Phe), tyrosine (Y orTyr), tryptophan (W orTrp), lysine (K or Lys), arginine (R or Arg), histidine (H or His), aspartic acid (D or Asp), glutamic acid (E or Glu), asparagine (N or Asn), glutamine (Q. or Gin), cysteine (C or Cys), methionine (M or Met), serine (S or Ser) and Threonine (T or Thr). Where a residue may be aspartic acid or asparagine, the symbols Asx or B may be used. Where a residue may be glutamic acid or glutamine, the symbols Glx or Z may be used. References to aspartic acid include aspartate, and glutamic acid include glutamate, unless the context specifies otherwise.

[0117] Amino acid deletions or insertions can also be made relative to the amino acid sequence for the fusion protein referred to below. Thus, for example, amino acids which do not have a substantial effect on the activity of the polypeptide, or at least which do not eliminate such activity, can be deleted. Such deletions can be advantageous since the overall length and the molecular weight of a polypeptide can be reduced whilst still retaining activity. This can enable the amount of polypeptide required for a particular purpose to be reduced - for example, dosage levels can be reduced. Thus, the amino acids glycine, alanine, valine, leucine and isoleucine can often be substituted for one another (amino acids having aliphatic side chains). Of these possible substitutions it is preferred that glycine and alanine are used to substitute for one another (since they have relatively short side chains) and that valine, leucine and isoleucine are used to substitute for one another (since they have larger aliphatic side chains which are hydrophobic). Other amino acids which can often be substituted for one another include: phenylalanine, tyrosine and tryptophan (amino acids having aromatic side chains); lysine, arginine and histidine (amino acids having basic side chains); aspartate and glutamate (amino acids having acidic side chains); asparagine and glutamine (amino acids having amide side chains); and cysteine and methionine (amino acids having sulphur containing side chains).

[0118] In some embodiments, the following amino acids can be exchange for each other for conservative amino acid substitutions:

[0119] Class Exchangeable amino acids

[0120] Aliphatic Glycine, Alanine, Valine, Leucine,

[0121] Isoleucine

[0122] Hydroxyl or Sulphur / Selenium-containing Serine, Cysteine, Threonine, Methionine

[0123] Aromatic Phenylalanine, Tyrosine, Tryptophan

[0124] Basic Histidine, Lysine, Arginine

[0125] Acidic and their Amide Aspartate, Glutamate, Asparagine,

[0126] Glutamine

[0127] Therefore, references to "conservative" amino acid substitutions refer to amino acid substitutions in which one or more of the amino acids in the sequence of the immunoconjugate or component parts (e.g. in the CDRs or in the VH or VL sequences) is substituted with another amino acid in the same class as indicated above. Conservative amino acid substitutions may be preferred in the CDR regions to minimise adverse effects on the function of the antibody. However, conservative amino acid substitutions may also occur in the framework regions.

[0128] Amino acid changes relative to the sequence given below can be made using any suitable technique e.g. by using site-directed mutagenesis or solid-state synthesis.

[0129] It should be appreciated that amino acid substitutions or insertions within the scope of the present invention can be made using naturally occurring or non-naturally occurring amino acids, although naturally occurring amino acids may be preferred. Whether or not natural or synthetic amino acids are used, it is preferred that only L- amino acids are present. Summary of antibody components

[0130] To outline the applicability of the approach a series of non-limiting example immunoconjugates are provided herein. These immunoconjugates comprise (a) a multivalent antibody or antigen-binding fragment thereof comprising (i) at least two antibody binding domains wherein: the first antibody binding domain specifically binds to a first target antigen selected from the group consisting of NKG2D, NKp30, NKp46, NKp44 and DNAM- 1; and the second antibody binding domain specifically binds to a second, different target antigen such as a TAA; and (ii) a human immunoglobulin Fc domain; and (b) at least one IL-15 receptor alpha (CD215) or a functional fragment thereof covalently linked to at least one C-terminus of the Fc domain.

[0131] The multivalent antibody or antigen-binding fragment thereof are multispecific, meaning each antibody binding domains bind to a different target. Preferably, the multivalent antibody or antigen-binding fragment thereof is a human antibody or antigen-binding fragment thereof.

[0132] A summary of the multivalent antibodies or antigen binding fragments thereof that may form the antibody component of these immunoconjugates is provided below in Table 2.

[0133] Table 2

[0134] As will be understood, any of the multivalent antibodies or antigen-binding fragments thereof may be suitably combined with the various IL-15 components (at least one IL-15 receptor alpha (CD215) or a functional fragment thereof and optionally an IL-15 cytokine covalently or non-covalently associated) presented herein and the components arranged into the different arrangements and formats of immunoconjugate described herein.

[0135] The immunoconjugates of the invention comprise a multivalent antibody or antigen-binding fragment thereof, comprising at least two antibody binding domains wherein: the first antibody binding domain specifically binds to a first target antigen selected from the group consisting of NKG2D, NKp30, NKp46, NKp44 and DNAM-1; and the second antibody binding domain specifically binds to a second, different target antigen such as a TAA. The TAA may be selected from the group consisting of HER2, EGFR, CD19 and CD20. Preferably, the second antibody binding domain specifically binds to a second target antigen which is HER2. Preferably the immunoconjugate comprises exactly two antibody binding domains. The first antibody binding domain may specifically bind to a first target antigen selected from the group consisting of NKG2D, NKp30 and NKp46; and the second antibody binding domain specifically binds to a second, different target antigen which is a TAA. Preferably the first antibody binding domain specifically binds to NKG2D and the second antibody binding domain specifically binds to a second, different target antigen which is a TAA. Even more preferably, the first antibody binding domain specifically binds to NKG2D and the second antibody binding domain specifically binds HER2.

[0136] The term "tumour associated antigen" (also known as a TAA or cancer associated antigen) as used herein refers to an antigen that is typically expressed on a tumour or cancer cell but not on a healthy, non-cancerous cell. This term also encompasses antigens that are expressed at elevated levels (overexpressed) on tumour or cancer cells and only expressed at lower or normal levels on healthy, non-cancerous cells or are otherwise primarily expressed at the embryonic phase of human development. TAAs can be useful for identifying the presence of tumour cells or targeting tumour cells. TAAs are well known in the art, and examples include HER2 (also known as ErbB2), EGFR, CD19 and CD20. Monoclonal antibodies that bind to tumour associated antigens are known in the art. For example, the anti-HER2 antibody Trastuzumab (HERCEPTIN®) is known in the art.

[0137] The immunoconjugate may comprise a first antibody binding domain that specifically binds to human and / or cynomologous NKG2D.

[0138] The immunoconjugate may comprise a first antibody binding domain that specifically binds to human and / or cynomologous NKp30.

[0139] The immunoconjugate may comprise a first antibody binding domain that specifically binds to human and / or cynomologous NKp46. The immunoconjugate may comprise a first antibody binding domain that specifically binds to human and / or cynomologous NKp44.

[0140] The immunoconjugate may comprise a first antibody binding domain that specifically binds to human and / or cynomologous DNAM-1.

[0141] The immunoconjugate may comprise a second antibody binding domain that specifically binds to a second, different target antigen which is not NKG2D, NKp30, NKp46, NKp44 or DNAM-1. The immunoconjugate may comprise a second antibody binding domain that specifically binds to a tumour associated antigen (TAA). The immunoconjugate may comprise a second antibody binding domain that specifically binds to a tumour associated antigen (TAA) and is not NKG2D, NKp30, NKp46, NKp44 or DNAM-1.

[0142] The immunoconjugate may comprise a first antibody binding domain that specifically binds to human NKG2D and a second antibody binding domain that specifically binds to a TAA.

[0143] The immunoconjugate may comprise a first antibody binding domain that specifically binds to human NKG2D and a second antibody binding domain that specifically binds to HER2.

[0144] The immunoconjugate may comprise a first antibody binding domain that specifically binds to human NKG2D and a second antibody binding domain that specifically binds to EGFR.

[0145] The immunoconjugate may comprise a first antibody binding domain that specifically binds to human NKG2D and a second antibody binding domain that specifically binds to CD19.

[0146] The immunoconjugate may comprise a first antibody binding domain that specifically binds to human NKG2D and a second antibody binding domain that specifically binds to CD20.

[0147] The immunoconjugate may comprise a first antibody binding domain that specifically binds to human NKp30 and a second antibody binding domain that specifically binds to a TAA, such as HER2, EGFR, CD19 or CD20.

[0148] The immunoconjugate may comprise a first antibody binding domain that specifically binds to human NKp46 and a second antibody binding domain that specifically binds to a TAA, such as HER2, EGFR, CD19 or CD20. The immunoconjugate may comprise a first antibody binding domain that specifically binds to human NKp44 and a second antibody binding domain that specifically binds to a TAA, such as HER2, EGFR, CD19 or CD20.

[0149] The immunoconjugate may comprise a first antibody binding domain that specifically binds to human DNAM-1 and a second antibody binding domain that specifically binds to a TAA, such as HER2, EGFR, CD19 or CD20.

[0150] The first antibody binding domain of the multivalent antibody component of the immunoconjugates of the invention can be derived from antibodies that bind to each of the targets selected from the group consisting of NKG2D, NKp30 and NKp46. For example any of the antibodies disclosed herein (see Table 2) as Hl / Ll - H13 / L13. The skilled person can equally select another suitable antibody that binds to one of the targets and utilise their skill in the art to combine the antibodies with second antibody binding domain and the other components of the immunoconjugates.

[0151] The first antibody binding domain may comprise: a) a heavy chain variable region (VH) comprising: i. a heavy chain complementary determining region (HCDR) 1 comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 1 to 13, optionally having up to 2 amino acid substitutions therefrom; ii. a HCDR2 comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 14 to 26, optionally having up to 2 amino acid substitutions therefrom; and ill. a HCDR3 comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 27 to 39, optionally having up to 2 amino acid substitutions therefrom; and b) a light chain variable region (VL) comprising: i. a light chain complementarity determining region (LCDR) 1 comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 40 to 52, optionally having up to 2 amino acid substitutions therefrom; ii. a LCDR2 comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 53 to 65, optionally having up to 2 amino acid substitutions therefrom; and ill. a LCDR3 comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 66 to 78, optionally having up to 2 amino acid substitutions therefrom.

[0152] The optional amino acid substitutions may be conservative substitutions. The first antibody binding domain may comprise: a) a heavy chain variable region (VH) comprising or consisting of a sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 95%, at least 97%, at least 98% or at least 99% identity to a sequence selected from the group consisting of SEQ ID NOs: 79 to 91 and 202; and b) a light chain variable region (VL) comprising or consisting of a sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 95%, at least 97%, at least 98% or at least 99% identity to a sequence selected from the group consisting of SEQ ID NOs: 92 to 104.

[0153] In some embodiments, the immunoconjugate comprises a multivalent antibody or antigen-binding fragment thereof that comprises: a) a VH comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 79 to 91 and 202; and b) a VL comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 92 to 104.

[0154] The first antibody binding domain may comprise: a) a heavy chain comprising or consisting of a sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 95%, at least 97%, at least 98% or at least 99% identity to a sequence selected from the group consisting of SEQ ID NOs: 109 to 134; and b) a light chain comprising or consisting of a sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 95%, at least 97%, at least 98% or at least 99% identity to a sequence selected from the group consisting of SEQ ID NOs: 135 to 147.

[0155] The first antibody binding domain may comprise: a) a heavy chain comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 109 to 134; and b) a light chain comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 135 to 147.

[0156] The first antibody binding domain may comprise: a) the six CDR sequences; b) the VH and or the VL sequences; and / or c) the heavy chain and / or the light chain sequences of an antibody that binds to N Kp44.

[0157] The first antibody binding domain may comprise: a) the six CDR sequences; b) the VH and or the VL sequences; and / or c) the heavy chain and / or the light chain sequences of an antibody that binds to DNAM-1.

[0158] Each of these first antibody binding domains may be paired with a suitable second antibody binding domain that binds to second different antigen, such as a TAA.

[0159] The multivalent antibody or antigen binding fragment thereof may comprise: a first antibody binding domain comprising: a) a heavy chain variable region (VH) comprising: i. a heavy chain complementary determining region (HCDR) 1 comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 1 to 13, optionally having up to 2 amino acid substitutions therefrom; ii. a HCDR2 comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 14 to 26, optionally having up to 2 amino acid substitutions therefrom; and ill. a HCDR3 comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 27 to 39, optionally having up to 2 amino acid substitutions therefrom; and b) a light chain variable region (VL) comprising: iv. a light chain complementarity determining region (LCDR) 1 comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 40 to 52, optionally having up to 2 amino acid substitutions therefrom; v. a LCDR2 comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 53 to 65, optionally having up to 2 amino acid substitutions therefrom; and vi. a LCDR3 comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 66 to 78, optionally having up to 2 amino acid substitutions therefrom; and a second antibody binding domain comprising: c) a heavy chain variable region (VH) comprising HCDR1, HCDR2, HCDR3 and a light chain variable region (VL) comprising LCDR1, LCRD2 and LCDR3 of an antibody that specially binds to a TAA. The multivalent antibody or antigen binding fragment thereof may comprise: a first antibody binding domain comprising: a) a heavy chain variable region (VH) comprising: i. a heavy chain complementary determining region (HCDR) 1 comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 1 to 13, optionally having up to 2 amino acid substitutions therefrom; ii. a HCDR2 comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 14 to 26, optionally having up to 2 amino acid substitutions therefrom; and ill. a HCDR3 comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 27 to 39, optionally having up to 2 amino acid substitutions therefrom; and b) a light chain variable region (VL) comprising: iv. a light chain complementarity determining region (LCDR) 1 comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 40 to 52, optionally having up to 2 amino acid substitutions therefrom; v. a LCDR2 comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 53 to 65, optionally having up to 2 amino acid substitutions therefrom; and vi. a LCDR3 comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 66 to 78, optionally having up to 2 amino acid substitutions therefrom; and a second antibody binding domain comprising: a) a heavy chain variable region (VH) comprising: i) a heavy chain complementary determining region (HCDR) 1 comprising or consisting of a sequence of SEQ ID NO: 330, optionally having up to 2 amino acid substitutions therefrom; ii) a HCDR2 comprising or consisting of a sequence of SEQ ID NOs: 331, optionally having up to 2 amino acid substitutions therefrom; and ill) a HCDR3 comprising or consisting of a sequence of SEQ ID NOs: 332, optionally having up to 2 amino acid substitutions therefrom; and b) a light chain variable region (VL) comprising: i. a light chain complementarity determining region (LCDR) 1 comprising or consisting of a sequence of SEQ ID NOs: 333, optionally having up to 2 amino acid substitutions therefrom; ii. a LCDR2 comprising or consisting of a sequence of SEQ ID NOs: 334, optionally having up to 2 amino acid substitutions therefrom; and iii. a LCDR3 comprising or consisting of a sequence of SEQ ID NOs: 335, optionally having up to 2 amino acid substitutions therefrom.

[0160] The optional amino acid substitutions may be conservative substitutions.

[0161] The multivalent antibody or antigen binding fragment thereof may comprise: a first antibody binding domain comprising: a) a heavy chain variable region (VH) comprising or consisting of a sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 95%, at least 97%, at least 98% or at least 99% identity to a sequence selected from the group consisting of SEQ ID NOs: 79 to 91 and 202; and b) a light chain variable region (VL) comprising or consisting of a sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 95%, at least 97%, at least 98% or at least 99% identity to a sequence selected from the group consisting of SEQ ID NOs: 92 to 104; and a second antibody binding domain comprising: c) a heavy chain variable region (VH) comprising HCDR1, HCDR2, HCDR3 and a light chain variable region (VL) comprising LCDR1, LCRD2 and LCDR3 of an antibody which specially binds to a TAA.

[0162] The multivalent antibody or antigen binding fragment thereof may comprise: a first antibody binding domain comprising: a) a VH comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 79 to 91 and 202; and b) a VL comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 92 to 104; and a second antibody binding domain comprising: c) a heavy chain variable region (VH) comprising HCDR1, HCDR2, HCDR3 and a light chain variable region (VL) comprising LCDR1, LCRD2 and LCDR3 of an antibody which specially binds to a TAA.

[0163] The multivalent antibody or antigen binding fragment thereof may comprise: a first antibody binding domain comprising: a) a heavy chain comprising or consisting of a sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 95%, at least 97%, at least 98% or at least 99% identity to a sequence selected from the group consisting of SEQ ID NOs: 109 to 134; and b) a light chain comprising or consisting of a sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 95%, at least 97%, at least 98% or at least 99% identity to a sequence selected from the group consisting of SEQ ID NOs: 135 to 147; and a second antibody binding domain comprising: c) a heavy chain variable region ( VH ) comprising HCDR1, HCDR2, HCDR3 and a light chain variable region (VL) comprising LCDR1, LCRD2 and LCDR3 of an antibody which specially binds to a TAA.

[0164] The multivalent antibody or antigen binding fragment thereof may comprise: a first antibody binding domain comprising: a) a heavy chain comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 109 to 134; and b) a light chain comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 135 to 147; and a second antibody binding domain comprising: c) a heavy chain variable region (VH) comprising HCDR1, HCDR2, HCDR3 and a light chain variable region (VL) comprising LCDR1, LCRD2 and LCDR3 of an antibody which specially binds to a TAA.

[0165] The multivalent antibody or antigen binding fragment thereof may comprise: a) a first antibody binding domain comprising a heavy chain variable region (VH) comprising HCDR1, HCDR2, HCDR3 and a light chain variable region (VL) comprising LCDR1, LCRD2 and LCDR3 of an antibody that specifically binds to NKp44; and b) a second antibody binding domain comprising a heavy chain variable region (VH) comprising HCDR1, HCDR2, HCDR3 and a light chain variable region (VL) comprising LCDR1, LCRD2 and LCDR3 of an antibody that specifically binds to a TAA.

[0166] The multivalent antibody or antigen binding fragment thereof may comprise: a) a first antibody binding domain comprising a heavy chain variable region (VH) comprising HCDR1, HCDR2, HCDR3 and a light chain variable region (VL) comprising LCDR1, LCRD2 and LCDR3 of an antibody that specifically binds to DNAM-1; and b) a second antibody binding domain comprising a heavy chain variable region (VH) comprising HCDR1, HCDR2, HCDR3 and a light chain variable region (VL) comprising LCDR1, LCRD2 and LCDR3 of an antibody that specifically binds to a TAA. Fc domains

[0167] The immunoconjugates of the invention comprise a human immunoglobulin Fc domain comprising a first chain comprising in an N- to C- terminal direction a CH2 domain and a CH3 domain; and a second chain comprising in an N- to C- terminal direction a CH2 domain and a CH3 domain. The multivalent antibody or fragment thereof may further comprise a CHI domain and hinge domain such that the multivalent antibody or fragment thereof comprises a CHI domain, a hinge domain, a CH2 domain and a CH3 domain e.g. SEQ ID NO: 105.

[0168] In some embodiments, the Fc domain of the multivalent antibody or fragment thereof is Fc disabled e.g. SEQ ID NO: 106. In some embodiments, the Fc domain of the multivalent antibody or fragment thereof comprises a substitution with respect to a wild-type Fc sequence, wherein the substitution reduces binding of the Fc domain to an Fc receptor. In some embodiments, the substitution is a substitution at a position selected from the group consisting of L234, L235, G236, G237 and P329 (EU index numbering), optionally wherein the substitution is selected from the group consisting of L235A, G237A, P329S and P329G (EU index numbering). These listed substitutions are not intended to be limiting as the skilled person is aware of multiple alternative substitutions which are known in the art and can be utilised to disable to reduce binding of the Fc domain to an Fc receptor. In a preferred embodiment, the substitutions are L234A and L235A (LALA), optionally with P329G or P329S. In another preferred embodiment, the substitutions are L235A and G237A (LAGA) (SEQ ID NO: 106), optionally with P329G (SEQ ID NO: 203) or P329S.

[0169] For antibodies or fragments thereof containing Fc domains, there are a number of established ways to reduce the binding of the Fc domain to Fc gamma Receptors such CD16, CD32 and CD64. Non-exhaustive examples include

[0170] • Choice of isotype - For example, wild-type and / or further modified lgG4 isotypes typically bind a number of FcR with reduced affinity versus IgGl isotypes. Hence one option to reduce FcR binding in our immunoconjugates could involve replacing or substituting hinged-IgGl domains with hinged-lgG4, or fragments thereof to generate lgGl / G4 chimeric hinged-Fc domains. This approach is well summarised in Dumet et al 2019 (MAbs. 2019 Nov-Dec; 11(8): 1341-1350)

[0171] • Glycosylation modification: Human IgGl Asn297 (EU numbering) positioned in the CH2 domain is heavily glycosylated. However, mutation of this position (eg N297A) results in aglycosylated antibodies with reduced FcR binding and reduced ADCC activity. Hence another approach to reduce FcR binding of our immunocojugates could involve mutating or deleting N297. • Mutation of critical residues in the hinge / CH2 domain of an IgG: There are a variety of established ways by which one can mutate an IgG to reduce FcR binding and ADCC activity. A non-exhaustive list of examples is provided in WO2021234402.

[0172] Table 3 Examples of therapeutic IgG antibodies which include combinations of mutations in the Fc region that may reduce binding to Fc-gamma-Rs and / or Clq. WHO I NN name for each molecule also included. Adapted from WO2021234402, Table 2.

[0173] Table 4 Examples of individual mutations in the Fc region of human IgG 1 considered to result in reduced binding to FcyR. Amino acid residues are listed according to the single letter code and numbered according to the EU system. These mutations are typically incorporated in combination into an IgG 1 Fc domain to ensure significant reduction in FcR binding. Variants reported in this table are included if they were reported as giving reduced binding to all Fc-gamma receptor or were reported as giving less than 50% binding to Fc gamma Rl, Fc gamma RIIA and Fc gamma Rl when compared to the wild-type IgGl Fc domain. Adapted from WO2021234402, Table 1.

[0174] Table 3 and 4 therefore provide a number of non-limiting ways by which human antibody Fc domains can be modified resulting in an antibody with 'reduced binding' to FcR or FcRs. For clarity, reduced binding here refers to a decrease in affinity to an FcR or multiple FcR as measured by SPR relative to a starting wild-type IgGl Fc domain. For further clarity, the term also includes reduction of affinity to zero (or below detection limit of the analytical method) i.e. complete abolishment of the interaction between the Fc domain and the FcR. The multivalent antibody or fragment thereof may further comprise a CHI domain and hinge domain such that the multivalent antibody or fragment thereof comprises a CHI domain, a hinge domain, a CH2 domain and a CH3 domain and the FC domain is Fc disabled e.g. SEQ ID NO: 106 or 203.

[0175] In some embodiments, the constant domain of the multivalent antibody or fragment thereof comprises: a) a heavy chain sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 95%, at least 97%, at least 98%, at least 99% identity or 100% identity to a human IgGl Fc domain or to a human IgGl Fc disabled domain; and b) a light chain sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 95%, at least 97%, at least 98%, at least 99% identity, or 100% identity to a light chain constant Kappa domain or to a light chain constant Lambda domain.

[0176] In some embodiments, the constant domain of the multivalent antibody or fragment thereof comprises: a) a heavy chain sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 95%, at least 97%, at least 98%, at least 99% identity or 100% identity to a human IgGl CHl-hinge-Fc domain or to a human IgGl CHl-hinge-Fc disabled domain; and b) a light chain sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 95%, at least 97%, at least 98%, at least 99% identity, or 100% identity to a light chain constant Kappa domain or to a light chain constant Lambda domain.

[0177] In some embodiments, the constant domain of the multivalent antibody or fragment thereof comprises: a) a heavy chain sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 95%, at least 97%, at least 98% or at least 99% identity to a sequence selected from the group consisting of SEQ ID NOs: 105, 106 and 203; and b) a light chain sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 95%, at least 97%, at least 98% or at least 99% identity to a sequence selected from the group consisting of SEQ ID NOs: 107 to 108.

[0178] Fc heterodimerisation domains

[0179] As described above, one of the areas explored in this application was to remove one of the anti-NKG2D binding domains described in the "2+2" formats of PCT / EP2024 / 053368 and replacing it with another binding domain targeting a second antigen resulting in a format termed "2+1+1" as described herein. The "2+1+1" immunoconjugates are therefore multispecific (bispecific) binders. Methods for generating bispecific binders are known in the art, for example Fc based bispecific binders that are formed though pairing of two distinct Fc heavy chains that are engineered to dimerize. These methods enable an Fc domain to be assembled from two different heavy chains, each fused to or comprising an antibody binding domain. The antibody binding domains can be directed to different targets to generate multi-specific binders.

[0180] The immunoconjugates may comprise an Fc domain which has been engineered to promote heterodimerization of the two heavy chains. The immunoconjugates may comprise an Fc domain wherein the CH3 domain of the first chain is engineered to heterodimerise with the CH3 domain of the second chain and / or the CH3 domain of the second chain is engineered to heterodimerise with the CH3 domain of the first chain.

[0181] The concept behind such heterodimerisation technologies is to facilitate the formation of heterodimers by the addition of complementary 'steric' variants in each chain. As used herein, the term "engineered to heterodimerise" refers to a polypeptide domain that has been altered such that it is more likely to associate with a different polypeptide domain than it is to associate with an identical polypeptide domain. In the context of a Fc domain, which comprises two heavy chains, "engineered to heterodimerise" refers to changing amino acids in each heavy chain such that different heavy chains are more likely to associate to form the heterodimeric structure than to form homodimers with the same Fc amino acid sequences. Methods to generate these asymmetric bispecific binders through heterodimerisation of two different Fc heavy chains, or fragments thereof, include but are not limited to: knobs-into-holes (KIH), CH3 charge pairing, Fab-arm exchange, SEED technology, BEAT technology, HA-TF, ZW1 approach, Biclonic approach, EW-RVT and Triomab See for example, Ridgeway et al, (1996) Protein Engineering 9:7, 617-621, Brinkman & Kontermann, (2017) mAbs, 9:2, 182-212; Klein et al (2012) mAbs 4:6, 653-663; Wang et al (2019) Antibodies, 8, 43; and Dietrich et al (2020) BBA - Proteins and Proteomics 1868 140250; each of which is incorporated herein by reference in its entirety. Examples of suitable steric variants are included in FIG. 29 of US 15 / 141,350. This is reproduced herein as Table 5, and describes non-exhaustive pairs of Fc modifications to allow for heterodimer formation and / or purification away from homodimers. The heterodimeric fusion constructs are based on the self-assembling nature of the two Fc domains, e.g., two "monomers" that assemble into a "dimer". There are a number of suitable pairs of sets of heterodimerization variants. These variants come in "pairs" of "sets". That is, one set of the pair is incorporated into the first monomer and the other set of the pair is incorporated into the second monomer. It should be noted that these sets of modifications do not necessarily contact with a one-to-one correspondence. For example, one Fc monomer may have 4 modifications in a set, whilst the partner Fc monomer may only have 2 modifications in a set. Regardless, pairs of sets form an interface between the two Fc monomers that encourages heterodimer formation and discourages homodimer formation, allowing the percentage of heterodimers that spontaneously form under biological conditions to be up to over 90%, rather than the expected 50% (25% homodimer A / A:50% heterodimer A / B:25% homodimer B / B).

[0182] One mechanism for engineering heterodimerization in Fc domains is generally referred to in the art as "knobs and holes" or "Knobs in holes" or "KiH". This refers to amino acid engineering that creates steric influences to favour heterodimeric formation and disfavour homodimeric formation, as described in U.S. Ser. No. 61 / 596,846, Ridgway et al. (ibid); Atwell et al., (1997) J. Mol. Biol. 270:26 and U.S. Pat. No. 8,216,805, all of which are hereby incorporated by reference in their entirety. The Figures identify a number of "monomer A- monomer B" pairs that rely on "knobs and holes". KIH generally refers to engineering the antibody constant domains, typically the CH3 domains, of two distinct heavy chains to create either a "knob" or a "hole" in each chain to promote heterodimerization and / or reduce homodimerization. For example, a knob can be formed by introducing a bulky amino acid (Tyr) at position 366 (EU numbering), while the hole can be formed by replacing a bulky amino acid (Tyr) at position 407 with a smaller one (Thr). The knob fits into the hole of the opposite chain, resulting in a stable and specific heterodimeric Fc region. To stabilize such heterodimerization, additional and complementary cysteine modification can also be included such that the resulting heterodimer included an additional cys-cys covalent bond. In addition, as described in Merchant et al., (1998) Nature Biotech. 16:677, these "knobs and hole" mutations can be combined with disulfide bonds to further 'skew' formation to heterodimerization - another commonly employed and complimentary approach. An additional mechanism that finds use in the generation of heterodimers is sometimes referred to as "electrostatic steering" as described in Gunasekaran et al., (2010) J. Biol. Chem. 285(25) :19637, hereby incorporated by reference in its entirety. This is sometimes referred to herein as "charge pairs". In this approach, electrostatics are used to skew the formation towards heterodimerization. As those in the art will appreciate, these may also have an effect on pl, and thus on purification, and thus could in some cases also be considered "pl variants". There is overlap between steric variant pairs and pl variant pairs. For further background, pl variants are of particular use if one is considering charge-change as a useful additional tool to increase the pl difference between a starting antibody species A and a starting antibody species B. In turn this also increases the charge or pl difference between the two unwanted A-A and B-B homodimers. In doing so, one can ensure the desired A-B heterodimer also has a unique and separate charge (typically sitting between the AA and BB impurities) when separated by charge. This approach can be particularly attractive when one is manufacturing proteins at a larger scale wherein typical chromatography polishing steps exploit charge to separate desired A-B heterodimer species away from less desired A-A and B-B homodimer species. For reference, an additional summary of pl variants and charge or steric complimenting variant set pairs is also provided in FIG. 37 of US 2012 / 0149876, all of which are incorporated expressly by reference herein.

[0183] Therefore, immunoconjugates may comprise a human immunoglobulin Fc domain wherein the CH3 domain of the first chain is engineered to heterodimerise with the CH3 domain of the second chain and / or the CH3 domain of the second chain is engineered to heterodimerise with the CH3 domain of the first chain. The CH3 domains may be engineered to heterodimerise by a method selected from the group consisting of knobs-into-holes (KIH), FORCE (format chain exchange), CH3 charge pairing, Fab-arm exchange, SEED technology, BEAT technology, HA-TF, ZW1 approach, Biclonic approach, EW-RVT and Triomab. Preferably, the CH3 domains may be engineered to heterodimerise by a knobs-into-holes (KIH) method. The CH3 domain of the first chain may comprise one or more amino acid substitution suitable for knobs-in-holes (KIH) dimerization with the CH3 domain of the second chain which may comprise one or more corresponding amino acid mutations. The first chain amino acid substitution may be referred to as the "knob" and the second chain amino acid substation may be referred to as the "hole". The CH3 domain of the first chain comprises one or more of the amino acid substitutions from the first column (Monomer A) of Table 5 and the CH3 domain of the second chain comprises one or more of the corresponding amino acid substitutions from the second column (Monomer B) of Table 5.

[0184] Table 5: Example pairs of sets of mutations (EU numbering) employed in heterodimerization (adapted from FIG. 29 of U.S. Ser. No. 15 / 141,350 inclusive of steric, pl, and skew variants).

[0185]

[0186] Preferably, multispecific immunoconjugates may comprise a human immunoglobulin Fc domain comprising a first chain comprising in an N- to C- terminal direction a CH2 domain and a CH3 domain; and a second chain comprising in an N- to C- terminal direction a CH2 domain and a CH3 domain; wherein the CH3 domain of the first chain comprises the mutation T366W (EU numbering) and the CH3 domain of the second chain comprises the mutations T366S, L368A, and Y407V (EU numbering). The CH3 domains may further comprise one or more residues mutated to cysteine residues capable of forming a disulphide bridge between the two CH3 domains (as described in Carter (2001) DOI: 10.1016 / s0022-1759(00)00339-2, incorporated herein by reference). The CH3 domain of the first chain may comprise the mutation S354C (EU numbering) and the CH3 domain of the second chain may comprise the mutation Y349C (EU numbering). These additional disulphide mutations may be combined with the preferred KiH mutations such that the CH3 domain of the first chain comprises the mutations S354C and T366W (EU numbering) and the CH3 domain of the second chain comprises the mutations Y349C, T366S, L368A, and Y407V (EU numbering).

[0187] Multispecific immunoconjugates of the invention may preferably comprise a human immunoglobulin Fc domain comprising a first chain comprising in an N- to C- terminal direction a CH2 domain and a CH3 domain; and a second chain comprising in an N- to C- terminal direction a CH2 domain and a CH3 domain; wherein the CH3 domain of the first chain comprises or consists of the sequence of SEQ ID NO: 270 and the CH3 domain of the second chain comprises or consists of the sequence of SEQ ID NO: 271. For reference, a wild type human CH3 domain has the sequence of SEQ. ID NO: 269. These Fc domains may be used with any of the antibody binding domains described herein and / or with any of the IL-15 components described herein.

[0188] The Fc domains engineered to heterodimerize may also be Fc disabled, as described in detail above. The CH3 KiH mutations described herein to promote heterodimerization may therefore be combined with any of the substitutions to reduce binding of the Fc domain to an Fc receptor as described herein, such as a substitution at a position selected from the group consisting of L234, L235, G236, G237 and P329 (EU index numbering), optionally wherein the substitution is selected from the group consisting of L235A, G237A, P329S and P329G (EU index numbering).

[0189] When employing CH3 modified knob-in-hole (KIH) technologies, chain pairing is important to ensure correct Fc heterodimerization for each half in the resulting asymmetric 2+1+1 or 1+1+1 formats as provided. Use of KiH ensures the Vh for Target 1 (eg the NKG2D target) is preferentially contained in a multispecific antibody alongside a Vh for Target 2 (eg. the TAA target of choice). It is also recommended that this is complemented with standard CL light chain pairing or biasing approaches such as polarity / charge switching or CL-CH1 switching such to ensure Vh for Target 1 pairs with VI for Target 1 and Vh for Target 2 pairs with VI for Target 2. It is therefore recognized that typically four expression cassettes are employed comprising different but paired constant domains sequences. In terms of constant domain paired sequences, these 4 expression cassettes are summarised below. Optionally these 4 cassettes are transfected and expressed from the same cell during production.

[0190] The Target 1 'half' of the multispecific immunoconjugate, resulting in the first and second polypeptide chains as shown in Figure 1C and ID:

[0191] • The first expressing cassette encodes the antibody heavy chain for Target 1 inclusive of the associated CHl-hinge-CH2-CH3 (or CL-hinge-CH2-CH3) constant sequence needed for pairing to its cognate light chain

[0192] • The second expression cassette encodes the antibody light chain for Target 1 inclusive of the associated CL (or CHI) constant sequence needed for pairing to its cognate heavy chain

[0193] The Target 2 'half' of the multispecifc immunoconjugate, resulting in the third and fourth polypeptide chains as shown in Figure 1C and ID: • The first expressing cassette encodes the antibody heavy chain for Target 2 inclusive of the associated CHl-hinge-CH2-CH3 (or CL-hinge-CH2-CH3) constant sequence needed for pairing to its cognate light chain

[0194] • The second expression cassette encodes the antibody light chain for Target 2 inclusive of the associated CL (or CHI) constant sequence needed for pairing to its cognate heavy chain

[0195] It is therefore recognized that regardless of the Vh or VI sequence or sushi domain and / or IL-15 moiety incorporated, there is a core sequence guiding correct heavy and light chain pairing and to which Vh or VI sequences are then attached at the N-terminus. These core sequences specifically comprise heavy and light chain matched pairs of heavy chain constant domain sequence (CHl-hinge-CH2-CH3) and light chain constant domain sequences (CL or CHI )

[0196] Non-exhaustive examples of matched core heavy chain and light constant domain sequence pairs are enclosed in the below tables (Table 6,7) wherein each matched core heavy chain / light chain constant sequence pair is arbitrarily prefixed A, B, or C (to highlight which heavy chain CHI / constant light chain sequence is employed) and suffixed with knob or hole (to highlight which heavy chain CH3 constant sequence is employed).

[0197] Table 6

[0198] Table 7

[0199] With reference to the above Tables 6 and 7 , it will be recognized that to generate the final multispecific immunoconjugates in the preferred formats, one preferred embodiment avoids use of identical heavy / light core constant domain sequence matched pairs for both Target 1 and Target 2 halves of the molecule. For example, to make a multispecific immunoconjugate as described herein, if Target 1 Vh / VI sequences are attached to a core sequence pair suffixed with 'knob', then Target 2 Vh / VI sequences are preferably not also attached to a pair suffixed with 'knob' but rather employs a pair suffixed with 'hole'.

[0200] To extend this further and in a similar manner, it will also be recognized that if Target 1 employs 'A' core sequence then more preferably Target 2 does not employ the same prefixed 'A' core sequence. For example, if Target 1 employs 'A' knob' then Target 2 does not employ 'A' hole but rather employs 'B hole' or 'C hole'

[0201] It will be recognized that given that there are a variety of matched sequence pairs which are non-identical for the respective Target 1 and Target 2 there are a number of alternate options to generate the final asymmetric, multispecific immunoconjugates. Some of the examples are outlined in the following Table 8 - again the same A, B, C prefix nomenclature is included but the knob / hole suffix is abbreviated to k or h respectively.

[0202] Table 8:

[0203] For the equivalent examples wherein the resulting immunoconjugates exhibit reduced FcR binding the following table 9 provides example core constant domain matched pairs of sequences.

[0204] Table 9

[0205] In some embodiments, the constant domain of the multivalent antibody or fragment thereof comprises: a) a heavy chain sequence selected from the group consisting of SEQ ID NOs: 105, 106, 203 and 314 to 325; and b) a light chain sequence selected from the group consisting of SEQ ID NOs: 107, 108, 299, 310 and 326.

[0206] In some embodiments, the constant domain of the multivalent antibody or fragment thereof comprises: a) a heavy chain sequence comprising or consisting of the sequence of SEQ ID NO: 105 and a light chain sequence comprising or consisting of the sequence of SEQ ID NO: 107; b) a heavy chain sequence comprising or consisting of the sequence of SEQ ID NO: 105 and a light chain sequence comprising or consisting of the sequence of SEQ ID NO: 108; c) a heavy chain sequence comprising or consisting of the sequence of SEQ ID NO: 106 and a light chain sequence comprising or consisting of the sequence of SEQ ID NO: 107; d) a heavy chain sequence comprising or consisting of the sequence of SEQ ID NO: 106 and a light chain sequence comprising or consisting of the sequence of SEQ ID NO: 108; e) a heavy chain sequence comprising or consisting of the sequence of SEQ ID NO: 203 and a light chain sequence comprising or consisting of the sequence of SEQ ID NO: 107; f) a heavy chain sequence comprising or consisting of the sequence of SEQ ID NO: 203 and a light chain sequence comprising or consisting of the sequence of SEQ ID NO: 108; g) a heavy chain sequence comprising or consisting of the sequence of SEQ ID NO: 314 and a light chain sequence comprising or consisting of the sequence of SEQ ID NO: 310; h) a heavy chain sequence comprising or consisting of the sequence of SEQ ID NO: 315 and a light chain sequence comprising or consisting of the sequence of SEQ ID NO: 310; i) a heavy chain sequence comprising or consisting of the sequence of SEQ ID NO: 316 and a light chain sequence comprising or consisting of the sequence of SEQ ID NO: 299; j) a heavy chain sequence comprising or consisting of the sequence of SEQ ID NO: 317 and a light chain sequence comprising or consisting of the sequence of SEQ ID NO: 299; k) a heavy chain sequence comprising or consisting of the sequence of SEQ ID NO: 318 and a light chain sequence comprising or consisting of the sequence of SEQ ID NO: 326; l) a heavy chain sequence comprising or consisting of the sequence of SEQ ID NO: 319 and a light chain sequence comprising or consisting of the sequence of SEQ ID NO: 326; m) a heavy chain sequence comprising or consisting of the sequence of SEQ ID NO: 320 and a light chain sequence comprising or consisting of the sequence of SEQ ID NO: 310; n) a heavy chain sequence comprising or consisting of the sequence of SEQ ID NO: 321 and a light chain sequence comprising or consisting of the sequence of SEQ ID NO: 310; o) a heavy chain sequence comprising or consisting of the sequence of SEQ ID NO: 322 and a light chain sequence comprising or consisting of the sequence of SEQ ID NO: 299; p) a heavy chain sequence comprising or consisting of the sequence of SEQ ID NO: 323 and a light chain sequence comprising or consisting of the sequence of SEQ ID NO: 299; q) a heavy chain sequence comprising or consisting of the sequence of SEQ ID NO: 324 and a light chain sequence comprising or consisting of the sequence of SEQ ID NO: 326; or r) a heavy chain sequence comprising or consisting of the sequence of SEQ ID NO: 325 and a light chain sequence comprising or consisting of the sequence of SEQ ID NO: 326. The heavy and light chain sequences as paired above may be combined with any of the antibody Vh / VI chains described herein as Hl / Ll to H13 / L13.

[0207] As set out above, the CH3 domains may be engineered to heterodimerise by methods other than knobs-into- holes (KIH), for example FORCE (format chain exchange), CH3 charge pairing, Fab-arm exchange, SEED technology, BEAT technology, HA-TF, ZW1 approach, Biclonic approach, EW-RVT and Triomab and further detail of immunoconjugate formats generated by such methods can be found in Example 5.

[0208] NKG2D antibody components

[0209] To further outline the applicability of the approach a series of non-limiting example immunoconjugates are provided herein. These immunoconjugates comprise (a) a multivalent antibody or antigen-binding fragment thereof comprising (i) at least two antibody binding domains wherein: the first antibody binding domain specifically binds to NKG2D; and the second antibody binding domain specifically binds to a second, different target antigen such as a TAA; and (ii) a human immunoglobulin Fc domain; and (b) at least one IL-15 receptor alpha (CD215) or a functional fragment thereof covalently linked to at least one C-terminus of the Fc domain.

[0210] A summary of the multivalent antibodies or antigen binding fragments thereof that form the antibody component of these NKG2D-IL-15Ra immunoconjugates is provided below.

[0211] Hl / Ll antibody component

[0212] In some embodiments, the first antibody binding domain of the multivalent antibody or antigen binding fragment thereof comprises sequences from the anti-NKG2D antibody described herein as Hl / Ll. These Hl / Ll components (whether described by CDR sequence, by VH / VL sequence, by heavy / light chain sequence or otherwise) can be paired with a second antibody binding domain that specifically binds to a TAA, preferably HER2.

[0213] The first antibody binding domain may comprise: a) a heavy chain variable region ( VH) comprising: i. a HCDR1 comprising or consisting of the sequence of SEQ ID NO: 1, optionally having up to 2 amino acid substitutions therefrom; ii. a HCDR2 comprising or consisting of the sequence of SEQ ID NO: 14, optionally having up to 2 amino acid substitutions therefrom; and ill. a HCDR3 comprising or consisting of the sequence of SEQ ID NO: 27, optionally having up to 2 amino acid substitutions therefrom; b) and a light chain variable region ( VL) comprising: i. a LCDR1 comprising or consisting of the sequence of SEQ ID NO: 40, optionally having up to 2 amino acid substitutions therefrom; ii. a LCDR2 comprising or consisting of the sequence of SEQ ID NO: 53, optionally having up to 2 amino acid substitutions therefrom; and ill. a LCDR3 comprising or consisting of the sequence of SEQ ID NO: 66, optionally having up to 2 amino acid substitutions therefrom.

[0214] The optional amino acid substitutions may be conservative substitutions.

[0215] The first antibody binding domain may comprise a VH comprising or consisting of the sequence of SEQ ID NO: 79 and a VL comprising or consisting of the sequence of SEQ ID NO: 92.

[0216] The first antibody binding domain may comprise a VH comprising or consisting of the sequence of SEQ ID NO: 202 and a VL comprising or consisting of the sequence of SEQ ID NO: 92. SEQ ID NO: 202 and SEQ ID NO: 79 comprise the same CDR regions, and only differ from each other in the framework region.

[0217] The first antibody binding domain may comprise a heavy chain comprising or consisting of the sequence of SEQ ID NO: 109 and a light chain comprising or consisting of the sequence SEQ ID NO: 135.

[0218] The first antibody binding domain may comprise a heavy chain comprising or consisting of the sequence of SEQ ID NO: 122 and a light chain comprising or consisting of the sequence SEQ ID NO: 135.

[0219] As will be understood, any of the first antibody binding domains comprising sequences from the anti-NKG2D antibody described herein as Hl / Ll may be suitably combined with any second antibody binding domain described herein. Any multivalent antibodies or antigen-binding fragments thereof comprising sequences from the anti-NKG2D antibody described herein as Hl / Ll may also be suitably combined with any of the IL-15 components (at least one IL-15 receptor alpha (CD215) or a functional fragment thereof and optionally an IL- 15 cytokine covalently or non-covalently associated) presented herein and the components arranged into any of the different arrangements and formats of immunoconjugate described herein. NKG2D - H2 / L2 antibody component

[0220] In some embodiments, the first antibody binding domain of the multivalent antibody or antigen binding fragment thereof comprises sequences from the anti-NKG2D antibody described herein as H2 / L2. These H2 / L2 components (whether described by CDR sequence, by VH / VL sequence, by heavy / light chain sequence or otherwise) can be paired with a second antibody binding domain that specifically binds to a TAA.

[0221] The first antibody binding domain may comprise: a) a heavy chain variable region (VH) comprising: i. a HCDR1 comprising or consisting of the sequence of SEQ ID NO: 2, optionally having up to 2 amino acid substitutions therefrom; ii. a HCDR2 comprising or consisting of the sequence of SEQ ID NO: 15, optionally having up to 2 amino acid substitutions therefrom; and ill. a HCDR3 comprising or consisting of the sequence of SEQ ID NO: 28, optionally having up to 2 amino acid substitutions therefrom; b) and a light chain variable region ( VL) comprising: i. a LCDR1 comprising or consisting of the sequence of SEQ ID NO: 41, optionally having up to 2 amino acid substitutions therefrom; ii. a LCDR2 comprising or consisting of the sequence of SEQ ID NO: 54, optionally having up to 2 amino acid substitutions therefrom; and ill. a LCDR3 comprising or consisting of the sequence of SEQ ID NO: 67, optionally having up to 2 amino acid substitutions therefrom;

[0222] The optional amino acid substitutions may be conservative substitutions.

[0223] The first antibody binding domain may comprise a VH comprising or consisting of the sequence of SEQ ID NO: 80 and a VL comprising or consisting of the sequence of SEQ ID NO: 93.

[0224] The first antibody binding domain may comprise a heavy chain comprising or consisting of the sequence of SEQ ID NO: 110 and a light chain comprising or consisting of the sequence SEQ ID NO: 136.

[0225] The first antibody binding domain may comprise a heavy chain comprising or consisting of the sequence of SEQ ID NO: 123 and a light chain comprising or consisting of the sequence SEQ ID NO: 136. As will be understood, any of the first antibody binding domains comprising sequences from the anti-NKG2D antibody described herein as H2 / L2 may be suitably combined with any second antibody binding domain described herein. Any multivalent antibodies or antigen-binding fragments thereof comprising sequences from the anti-NKG2D antibody described herein as H2 / L2 may also be suitably combined with any of the IL-15 components (at least one IL-15 receptor alpha (CD215) or a functional fragment thereof and optionally an IL- 15 cytokine covalently or non-covalently associated) presented herein and the components arranged into any of the different arrangements and formats of immunoconjugate described herein.

[0226] NKG2D - H3 / L3 antibody component

[0227] In some embodiments, the first antibody binding domain of the multivalent antibody or antigen binding fragment thereof comprises sequences from the anti-NKG2D antibody described herein as H3 / L3. These H3 / L3 components (whether described by CDR sequence, by VH / VL sequence, by heavy / light chain sequence or otherwise) can be paired with a second antibody binding domain that specifically binds to a TAA.

[0228] The first antibody binding domain may comprise: a. a heavy chain variable region (VH) comprising: i. a HCDR1 comprising or consisting of the sequence of SEQ ID NO: 3, optionally having up to 2 amino acid substitutions therefrom; ii. a HCDR2 comprising or consisting of the sequence of SEQ ID NO: 16, optionally having up to 2 amino acid substitutions therefrom; and ill. a HCDR3 comprising or consisting of the sequence of SEQ ID NO: 29, optionally having up to 2 amino acid substitutions therefrom; b. and a light chain variable region ( VL) comprising: i. a LCDR1 comprising or consisting of the sequence of SEQ ID NO: 42, optionally having up to 2 amino acid substitutions therefrom; ii. a LCDR2 comprising or consisting of the sequence of SEQ ID NO: 55, optionally having up to 2 amino acid substitutions therefrom; and ill. a LCDR3 comprising or consisting of the sequence of SEQ ID NO: 68, optionally having up to 2 amino acid substitutions therefrom.

[0229] The optional amino acid substitutions may be conservative substitutions. The first antibody binding domain may comprise a VH comprising or consisting of the sequence of SEQ ID NO: 81 and a VL comprising or consisting of the sequence of SEQ ID NO: 94.

[0230] The first antibody binding domain may comprise a heavy chain comprising or consisting of the sequence of SEQ ID NO: 111 and a light chain comprising or consisting of the sequence SEQ ID NO: 137.

[0231] The first antibody binding domain may comprise a heavy chain comprising or consisting of the sequence of SEQ ID NO: 124 and a light chain comprising or consisting of the sequence SEQ ID NO: 137.

[0232] As will be understood, any of the first antibody binding domains comprising sequences from the anti-NKG2D antibody described herein as H3 / L3 may be suitably combined with any second antibody binding domain described herein. Any multivalent antibodies or antigen-binding fragments thereof comprising sequences from the anti-NKG2D antibody described herein as H3 / L3 may also be suitably combined with any of the IL-15 components (at least one IL-15 receptor alpha (CD215) or a functional fragment thereof and optionally an IL- 15 cytokine covalently or non-covalently associated) presented herein and the components arranged into any of the different arrangements and formats of immunoconjugate described herein.

[0233] NKG2D - H4 / L4 antibody component

[0234] In some embodiments, the first antibody binding domain of the multivalent antibody or antigen binding fragment thereof comprises sequences from the anti-NKG2D antibody described herein as H4 / L4. These H4 / L4 components (whether described by CDR sequence, by VH / VL sequence, by heavy / light chain sequence or otherwise) can be paired with a second antibody binding domain that specifically binds to a TAA.

[0235] The first antibody binding domain may comprise: i. a heavy chain variable region (VH) comprising: a. a HCDR1 comprising or consisting of the sequence of SEQ ID NO: 4, optionally having up to 2 amino acid substitutions therefrom; b. a HCDR2 comprising or consisting of the sequence of SEQ ID NO: 17, optionally having up to 2 amino acid substitutions therefrom; and c. a HCDR3 comprising or consisting of the sequence of SEQ ID NO: 30, optionally having up to

[0236] 2 amino acid substitutions therefrom; ii. and a light chain variable region (VL) comprising: a. a LCDR1 comprising or consisting of the sequence of SEQ ID NO: 43, optionally having up to 2 amino acid substitutions therefrom; b. a LCDR2 comprising or consisting of the sequence of SEQ ID NO: 56, optionally having up to 2 amino acid substitutions therefrom; and c. a LCDR3 comprising or consisting of the sequence of SEQ ID NO: 69, optionally having up to 2 amino acid substitutions therefrom.

[0237] The optional amino acid substitutions may be conservative substitutions.

[0238] The first antibody binding domain may comprise a VH comprising or consisting of the sequence of SEQ ID NO: 82 and a VL comprising or consisting of the sequence of SEQ ID NO: 95.

[0239] The first antibody binding domain may comprise a heavy chain comprising or consisting of the sequence of SEQ ID NO: 112 and a light chain comprising or consisting of the sequence SEQ ID NO: 138.

[0240] The first antibody binding domain may comprise a heavy chain comprising or consisting of the sequence of SEQ ID NO: 125 and a light chain comprising or consisting of the sequence SEQ ID NO: 138.

[0241] As will be understood, any of the first antibody binding domains comprising sequences from the anti-NKG2D antibody described herein as H4 / L4 may be suitably combined with any second antibody binding domain described herein. Any multivalent antibodies or antigen-binding fragments thereof comprising sequences from the anti-NKG2D antibody described herein as H4 / L4 may also be suitably combined with any of the IL-15 components (at least one IL-15 receptor alpha (CD215) or a functional fragment thereof and optionally an IL- 15 cytokine covalently or non-covalently associated) presented herein and the components arranged into any of the different arrangements and formats of immunoconjugate described herein.

[0242] NKG2D - H5 / L5 antibody component

[0243] In some embodiments, the first antibody binding domain of the multivalent antibody or antigen binding fragment thereof comprises sequences from the anti-NKG2D antibody described herein as H5 / L5. These H5 / L5 components (whether described by CDR sequence, by VH / VL sequence, by heavy / light chain sequence or otherwise) can be paired with a second antibody binding domain that specifically binds to a TAA.

[0244] The first antibody binding domain may comprise: i. a heavy chain variable region (VH) comprising: a. a HCDR1 comprising or consisting of the sequence of SEQ ID NO: 5, optionally having up to 2 amino acid substitutions therefrom; b. a HCDR2 comprising or consisting of the sequence of SEQ ID NO: 18, optionally having up to 2 amino acid substitutions therefrom; and c. a HCDR3 comprising or consisting of the sequence of SEQ ID NO: 31, optionally having up to

[0245] 2 amino acid substitutions therefrom; ii. and a light chain variable region ( VL) comprising: a. a LCDR1 comprising or consisting of the sequence of SEQ ID NO: 44, optionally having up to 2 amino acid substitutions therefrom; b. a LCDR2 comprising or consisting of the sequence of SEQ ID NO: 57, optionally having up to 2 amino acid substitutions therefrom; and c. a LCDR3 comprising or consisting of the sequence of SEQ ID NO: 70, optionally having up to 2 amino acid substitutions therefrom.

[0246] The optional amino acid substitutions may be conservative substitutions.

[0247] The first antibody binding domain may comprise a VH comprising or consisting of the sequence of SEQ ID NO: 83 and a VL comprising or consisting of the sequence of SEQ ID NO: 96.

[0248] The first antibody binding domain may comprise a heavy chain comprising or consisting of the sequence of SEQ ID NO: 113 and a light chain comprising or consisting of the sequence SEQ ID NO: 139.

[0249] The first antibody binding domain may comprise a heavy chain comprising or consisting of the sequence of SEQ ID NO: 126 and a light chain comprising or consisting of the sequence SEQ ID NO: 139.

[0250] As will be understood, any of the first antibody binding domains comprising sequences from the anti-NKG2D antibody described herein as H5 / L5 may be suitably combined with any second antibody binding domain described herein. Any multivalent antibodies or antigen-binding fragments thereof comprising sequences from the anti-NKG2D antibody described herein as H5 / L5 may also be suitably combined with any of the IL-15 components (at least one IL-15 receptor alpha (CD215) or a functional fragment thereof and optionally an IL- 15 cytokine covalently or non-covalently associated) presented herein and the components arranged into any of the different arrangements and formats of immunoconjugate described herein. NKG2D - H6 / L6 antibody component

[0251] In some embodiments, the first antibody binding domain of the multivalent antibody or antigen binding fragment thereof comprises sequences from the anti-NKG2D antibody described herein as H6 / L6 (also referred to herein as 21F2). These H6 / L6 components (whether described by CDR sequence, by VH / VL sequence, by heavy / light chain sequence or otherwise) can be paired with a second antibody binding domain that specifically binds to a TAA.

[0252] The first antibody binding domain may comprise: i. a heavy chain variable region (VH) comprising: a. a HCDR1 comprising or consisting of the sequence of SEQ ID NO: 6, optionally having up to 2 amino acid substitutions therefrom; b. a HCDR2 comprising or consisting of the sequence of SEQ ID NO: 19, optionally having up to 2 amino acid substitutions therefrom; and c. a HCDR3 comprising or consisting of the sequence of SEQ ID NO: 32, optionally having up to

[0253] 2 amino acid substitutions therefrom; ii. and a light chain variable region ( VL) comprising: a. a LCDR1 comprising or consisting of the sequence of SEQ ID NO: 45, optionally having up to 2 amino acid substitutions therefrom; b. a LCDR2 comprising or consisting of the sequence of SEQ ID NO: 58, optionally having up to 2 amino acid substitutions therefrom; and c. a LCDR3 comprising or consisting of the sequence of SEQ ID NO: 71, optionally having up to 2 amino acid substitutions therefrom.

[0254] The optional amino acid substitutions may be conservative substitutions.

[0255] The first antibody binding domain may comprise a VH comprising or consisting of the sequence of SEQ ID NO: 84 and a VL comprising or consisting of the sequence of SEQ ID NO: 97.

[0256] The first antibody binding domain may comprise a heavy chain comprising or consisting of the sequence of SEQ ID NO: 114 and a light chain comprising or consisting of the sequence SEQ ID NO: 140. The first antibody binding domain may comprise a heavy chain comprising or consisting of the sequence of SEQ ID NO: 127 and a light chain comprising or consisting of the sequence SEQ ID NO: 140.

[0257] As will be understood, any of the first antibody binding domains comprising sequences from the anti-NKG2D antibody described herein as H6 / L6 may be suitably combined with any second antibody binding domain described herein. Any multivalent antibodies or antigen-binding fragments thereof comprising sequences from the anti-NKG2D antibody described herein as H6 / L6 may also be suitably combined with any of the IL-15 components (at least one IL-15 receptor alpha (CD215) or a functional fragment thereof and optionally an IL- 15 cytokine covalently or non-covalently associated) presented herein and the components arranged into any of the different arrangements and formats of immunoconjugate described herein.

[0258] NKG2D - H7 / L7 antibody component

[0259] In some embodiments, the first antibody binding domain of the multivalent antibody or antigen binding fragment thereof comprises sequences from the anti-NKG2D antibody described herein as H7 / L7. These H7 / L7 components (whether described by CDR sequence, by VH / VL sequence, by heavy / light chain sequence or otherwise) can be paired with a second antibody binding domain that specifically binds to a TAA.

[0260] The first antibody binding domain may comprise: i. a heavy chain variable region (VH) comprising: a. a HCDR1 comprising or consisting of the sequence of SEQ ID NO: 7, optionally having up to 2 amino acid substitutions therefrom; b. a HCDR2 comprising or consisting of the sequence of SEQ ID NO: 20, optionally having up to 2 amino acid substitutions therefrom; and c. a HCDR3 comprising or consisting of the sequence of SEQ ID NO: 33, optionally having up to 2 amino acid substitutions therefrom; ii. and a light chain variable region ( VL) comprising: a. a LCDR1 comprising or consisting of the sequence of SEQ ID NO: 46, optionally having up to 2 amino acid substitutions therefrom; b. a LCDR2 comprising or consisting of the sequence of SEQ ID NO: 59, optionally having up to 2 amino acid substitutions therefrom; and c. a LCDR3 comprising or consisting of the sequence of SEQ ID NO: 72, optionally having up to 2 amino acid substitutions therefrom. The optional amino acid substitutions may be conservative substitutions.

[0261] The first antibody binding domain may comprise a VH comprising or consisting of the sequence of SEQ ID NO: 85 and a VL comprising or consisting of the sequence of SEQ ID NO: 98.

[0262] The first antibody binding domain may comprise a heavy chain comprising or consisting of the sequence of SEQ ID NO: 115 and a light chain comprising or consisting of the sequence SEQ ID NO: 141.

[0263] The first antibody binding domain may comprise a heavy chain comprising or consisting of the sequence of SEQ ID NO: 128 and a light chain comprising or consisting of the sequence SEQ ID NO: 141.

[0264] As will be understood, any of the first antibody binding domains comprising sequences from the anti-NKG2D antibody described herein as H7 / L7 may be suitably combined with any second antibody binding domain described herein. Any multivalent antibodies or antigen-binding fragments thereof comprising sequences from the anti-NKG2D antibody described herein as H7 / L7 may also be suitably combined with any of the IL-15 components (at least one IL-15 receptor alpha (CD215) or a functional fragment thereof and optionally an IL- 15 cytokine covalently or non-covalently associated) presented herein and the components arranged into any of the different arrangements and formats of immunoconjugate described herein.

[0265] NKG2D - H8 / L8 antibody component

[0266] In some embodiments, the first antibody binding domain of the multivalent antibody or antigen binding fragment thereof comprises sequences from the anti-NKG2D antibody described herein as H8 / L8. These H8 / L8 components (whether described by CDR sequence, by VH / VL sequence, by heavy / light chain sequence or otherwise) can be paired with a second antibody binding domain that specifically binds to a TAA.

[0267] The first antibody binding domain may comprise: i. a heavy chain variable region (VH) comprising: a. a HCDR1 comprising or consisting of the sequence of SEQ ID NO: 8, optionally having up to 2 amino acid substitutions therefrom; b. a HCDR2 comprising or consisting of the sequence of SEQ ID NO: 21, optionally having up to 2 amino acid substitutions therefrom; and c. a HCDR3 comprising or consisting of the sequence of SEQ ID NO: 34, optionally having up to

[0268] 2 amino acid substitutions therefrom; ii. and a light chain variable region ( VL) comprising: a. a LCDR1 comprising or consisting of the sequence of SEQ ID NO: 47, optionally having up to 2 amino acid substitutions therefrom; b. a LCDR2 comprising or consisting of the sequence of SEQ ID NO: 60, optionally having up to 2 amino acid substitutions therefrom; and c. a LCDR3 comprising or consisting of the sequence of SEQ ID NO: 73, optionally having up to 2 amino acid substitutions therefrom.

[0269] The optional amino acid substitutions may be conservative substitutions.

[0270] The first antibody binding domain may comprise a VH comprising or consisting of the sequence of SEQ ID NO: 86 and a VL comprising or consisting of the sequence of SEQ ID NO: 99.

[0271] The first antibody binding domain may comprise a heavy chain comprising or consisting of the sequence of SEQ ID NO: 116 and a light chain comprising or consisting of the sequence SEQ ID NO: 142.

[0272] The first antibody binding domain may comprise a heavy chain comprising or consisting of the sequence of SEQ ID NO: 129 and a light chain comprising or consisting of the sequence SEQ ID NO: 142.

[0273] As will be understood, any of the first antibody binding domains comprising sequences from the anti-NKG2D antibody described herein as H8 / L8 may be suitably combined with any second antibody binding domain described herein. Any multivalent antibodies or antigen-binding fragments thereof comprising sequences from the anti-NKG2D antibody described herein as H8 / L8 may also be suitably combined with any of the IL-15 components (at least one IL-15 receptor alpha (CD215) or a functional fragment thereof and optionally an IL- 15 cytokine covalently or non-covalently associated) presented herein and the components arranged into any of the different arrangements and formats of immunoconjugate described herein.

[0274] NKG2D - H9 / L9 antibody component

[0275] In some embodiments, the first antibody binding domain of the multivalent antibody or antigen binding fragment thereof comprises sequences from the anti-NKG2D antibody described herein as H9 / L9. These H9 / L9 components (whether described by CDR sequence, by VH / VL sequence, by heavy / light chain sequence or otherwise) can be paired with a second antibody binding domain that specifically binds to a TAA. The first antibody binding domain may comprise: i. a heavy chain variable region (VH) comprising: a. a HCDR1 comprising or consisting of the sequence of SEQ ID NO: 9, optionally having up to 2 amino acid substitutions therefrom; b. a HCDR2 comprising or consisting of the sequence of SEQ ID NO: 22, optionally having up to

[0276] 2 amino acid substitutions therefrom; and c. a HCDR3 comprising or consisting of the sequence of SEQ ID NO: 35, optionally having up to

[0277] 2 amino acid substitutions therefrom; ii. and a light chain variable region ( VL) comprising: a. a LCDR1 comprising or consisting of the sequence of SEQ ID NO: 48, optionally having up to 2 amino acid substitutions therefrom; b. a LCDR2 comprising or consisting of the sequence of SEQ ID NO: 61, optionally having up to 2 amino acid substitutions therefrom; and c. a LCDR3 comprising or consisting of the sequence of SEQ ID NO: 74, optionally having up to 2 amino acid substitutions therefrom.

[0278] The optional amino acid substitutions may be conservative substitutions.

[0279] The first antibody binding domain may comprise a VH comprising or consisting of the sequence of SEQ ID NO: 87 and a VL comprising or consisting of the sequence of SEQ ID NO: 100.

[0280] The first antibody binding domain may comprise a heavy chain comprising or consisting of the sequence of SEQ ID NO: 117 and a light chain comprising or consisting of the sequence SEQ ID NO: 143.

[0281] The first antibody binding domain may comprise a heavy chain comprising or consisting of the sequence of SEQ ID NO: 130 and a light chain comprising or consisting of the sequence SEQ ID NO: 143.

[0282] As will be understood, any of the first antibody binding domains comprising sequences from the anti-NKG2D antibody described herein as H9 / L9 may be suitably combined with any second antibody binding domain described herein. Any multivalent antibodies or antigen-binding fragments thereof comprising sequences from the anti-NKG2D antibody described herein as H9 / L9 may also be suitably combined with any of the IL-15 components (at least one IL-15 receptor alpha (CD215) or a functional fragment thereof and optionally an IL- 15 cytokine covalently or non-covalently associated) presented herein and the components arranged into any of the different arrangements and formats of immunoconjugate described herein.

[0283] NKG2D - H10 / L10 antibody component

[0284] In some embodiments, the first antibody binding domain of the multivalent antibody or antigen binding fragment thereof comprises sequences from the anti-NKG2D antibody described herein as H10 / L10. These H10 / L10 components (whether described by CDR sequence, by VH / VLsequence, by heavy / light chain sequence or otherwise) can be paired with a second antibody binding domain that specifically binds to a TAA.

[0285] The first antibody binding domain may comprise: i. a heavy chain variable region (VH) comprising: a. a HCDR1 comprising or consisting of the sequence of SEQ ID NO: 10, optionally having up to

[0286] 2 amino acid substitutions therefrom; b. a HCDR2 comprising or consisting of the sequence of SEQ ID NO: 23, optionally having up to

[0287] 2 amino acid substitutions therefrom; and c. a HCDR3 comprising or consisting of the sequence of SEQ ID NO: 36, optionally having up to

[0288] 2 amino acid substitutions therefrom; ii. and a light chain variable region ( VL) comprising: a. a LCDR1 comprising or consisting of the sequence of SEQ ID NO: 49, optionally having up to 2 amino acid substitutions therefrom; b. a LCDR2 comprising or consisting of the sequence of SEQ ID NO: 62, optionally having up to 2 amino acid substitutions therefrom; and c. a LCDR3 comprising or consisting of the sequence of SEQ ID NO: 75, optionally having up to 2 amino acid substitutions therefrom.

[0289] The optional amino acid substitutions may be conservative substitutions.

[0290] The first antibody binding domain may comprise a VH comprising or consisting of the sequence of SEQ ID NO: 88 and a VL comprising or consisting of the sequence of SEQ ID NO: 101.

[0291] The first antibody binding domain may comprise a heavy chain comprising or consisting of the sequence of SEQ ID NO: 118 and a light chain comprising or consisting of the sequence SEQ ID NO: 144. The first antibody binding domain may comprise a heavy chain comprising or consisting of the sequence of SEQ ID NO: 131 and a light chain comprising or consisting of the sequence SEQ ID NO: 144.

[0292] As will be understood, any of the first antibody binding domains comprising sequences from the anti-NKG2D antibody described herein as H10 / L10 may be suitably combined with any second antibody binding domain described herein. Any multivalent antibodies or antigen-binding fragments thereof comprising sequences from the anti-NKG2D antibody described herein as H10 / L10 may also be suitably combined with any of the IL-15 components (at least one IL-15 receptor alpha (CD215) or a functional fragment thereof and optionally an IL- 15 cytokine covalently or non-covalently associated) presented herein and the components arranged into any of the different arrangements and formats of immunoconjugate described herein.

[0293] NKp30 antibody components

[0294] To further outline the applicability of the approach a series of non-limiting example immunoconjugates are provided herein. These immunoconjugates comprise (a) a multivalent antibody or antigen-binding fragment thereof comprising (i) at least two antibody binding domains wherein: the first antibody binding domain specifically binds to NKp30; and the second antibody binding domain specifically binds to a second, different target antigen such as a TAA; and (ii) a human immunoglobulin Fc domain; and (b) at least one IL-15 receptor alpha (CD215) or a functional fragment thereof covalently linked to at least one C-terminus of the Fc domain.

[0295] A summary of the multivalent antibodies or antigen binding fragments thereof that form the antibody component of these NKp30-IL-15Ra immunoconjugates is provided below.

[0296] Hll / Lll antibody component

[0297] In some embodiments, the first antibody binding domain of the multivalent antibody or antigen binding fragment thereof comprises sequences from the anti-NKp30 antibody described herein as Hll / Lll. These Hll / Lll components (whether described by CDR sequence, by VH / VL sequence, by heavy / light chain sequence or otherwise) can be paired with a second antibody binding domain that specifically binds to a TAA.

[0298] The first antibody binding domain may comprise: a) a heavy chain variable region (VH) comprising: i. a HCDR1 comprising or consisting of the sequence of SEQ ID NO: 11, optionally having up to 2 amino acid substitutions therefrom; ii. a HCDR2 comprising or consisting of the sequence of SEQ ID NO: 24, optionally having up to 2 amino acid substitutions therefrom; and ill. a HCDR3 comprising or consisting of the sequence of SEQ ID NO: 37, optionally having up to 2 amino acid substitutions therefrom; b) and a light chain variable region ( VL) comprising: i. a LCDR1 comprising or consisting of the sequence of SEQ ID NO: 50, optionally having up to 2 amino acid substitutions therefrom; ii. a LCDR2 comprising or consisting of the sequence of SEQ ID NO: 63, optionally having up to 2 amino acid substitutions therefrom; and ill. a LCDR3 comprising or consisting of the sequence of SEQ ID NO: 76, optionally having up to 2 amino acid substitutions therefrom.

[0299] The optional amino acid substitutions may be conservative substitutions.

[0300] The first antibody binding domain may comprise a VH comprising or consisting of the sequence of SEQ ID NO: 89 and a VL comprising or consisting of the sequence of SEQ ID NO: 102.

[0301] The first antibody binding domain may comprise a heavy chain comprising or consisting of the sequence of SEQ ID NO: 119 and a light chain comprising or consisting of the sequence SEQ ID NO: 145.

[0302] The first antibody binding domain may comprise a heavy chain comprising or consisting of the sequence of SEQ ID NO: 132 and a light chain comprising or consisting of the sequence SEQ ID NO: 145.

[0303] As will be understood, any of the first antibody binding domains comprising sequences from the anti-NKp30 antibody described herein as Hll / Lll may be suitably combined with any second antibody binding domain described herein. Any multivalent antibodies or antigen-binding fragments thereof comprising sequences from the anti-NKp30 antibody described herein as Hll / Lll may also be suitably combined with any of the IL-15 components (at least one IL-15 receptor alpha (CD215) or a functional fragment thereof and optionally an IL- 15 cytokine covalently or non-covalently associated) presented herein and the components arranged into any of the different arrangements and formats of immunoconjugate described herein.

[0304] NKp30 - H12 / L12 antibody component O In some embodiments, the first antibody binding domain of the multivalent antibody or antigen binding fragment thereof comprises sequences from the anti-NKp30 antibody described herein as H12 / L12. These H12 / L12 components (whether described by CDR sequence, by VH / VL sequence, by heavy / light chain sequence or otherwise) can be paired with a second antibody binding domain that specifically binds to a TAA.

[0305] The first antibody binding domain may comprise: a) a heavy chain variable region (VH) comprising: i. a HCDR1 comprising or consisting of the sequence of SEQ ID NO: 12, optionally having up to 2 amino acid substitutions therefrom; ii. a HCDR2 comprising or consisting of the sequence of SEQ ID NO: 25, optionally having up to 2 amino acid substitutions therefrom; and ill. a HCDR3 comprising or consisting of the sequence of SEQ ID NO: 38, optionally having up to 2 amino acid substitutions therefrom; b) and a light chain variable region (VL) comprising: i. a LCDR1 comprising or consisting of the sequence of SEQ ID NO: 51, optionally having up to 2 amino acid substitutions therefrom; ii. a LCDR2 comprising or consisting of the sequence of SEQ ID NO: 64, optionally having up to 2 amino acid substitutions therefrom; and ill. a LCDR3 comprising or consisting of the sequence of SEQ ID NO: 77, optionally having up to 2 amino acid substitutions therefrom.

[0306] The optional amino acid substitutions may be conservative substitutions.

[0307] The first antibody binding domain may comprise a VH comprising or consisting of the sequence of SEQ ID NO: 90 and a VL comprising or consisting of the sequence of SEQ ID NO: 103.

[0308] The first antibody binding domain may comprise a heavy chain comprising or consisting of the sequence of SEQ ID NO: 120 and a light chain comprising or consisting of the sequence SEQ ID NO: 146.

[0309] The first antibody binding domain may comprise a heavy chain comprising or consisting of the sequence of SEQ ID NO: 133 and a light chain comprising or consisting of the sequence SEQ ID NO: 146. As will be understood, any of the first antibody binding domains comprising sequences from the anti-NKp30 antibody described herein as H12 / L12 may be suitably combined with any second antibody binding domain described herein. Any multivalent antibodies or antigen-binding fragments thereof comprising sequences from the anti-NKp30 antibody described herein as H12 / L12 may also be suitably combined with any of the IL-15 components (at least one IL-15 receptor alpha (CD215) or a functional fragment thereof and optionally an IL- 15 cytokine covalently or non-covalently associated) presented herein and the components arranged into any of the different arrangements and formats of immunoconjugate described herein.

[0310] NKp46 antibody components

[0311] To further outline the applicability of the approach a series of non-limiting example immunoconjugates are provided herein. These immunoconjugates comprise (a) a multivalent antibody or antigen-binding fragment thereof comprising (i) at least two antibody binding domains wherein: the first antibody binding domain specifically binds to NKp46; and the second antibody binding domain specifically binds to a second, different target antigen such as a TAA; and (ii) a human immunoglobulin Fc domain; and (b) at least one IL-15 receptor alpha (CD215) or a functional fragment thereof covalently linked to at least one C-terminus of the Fc domain.

[0312] A summary of the multivalent antibodies or antigen binding fragments thereof that form the antibody component of these NKp46-IL-15Ra immunoconjugates is provided below.

[0313] H13 / L13 antibody component

[0314] In some embodiments, the first antibody binding domain of the multivalent antibody or antigen binding fragment thereof comprises sequences from the anti-NKp46 antibody described herein as H13 / L13. These H13 / L13 components (whether described by CDR sequence, by VH / VL sequence, by heavy / light chain sequence or otherwise) can be paired with a second antibody binding domain that specifically binds to a TAA.

[0315] The first antibody binding domain may comprise: a) a heavy chain variable region (VH) comprising: i. a HCDR1 comprising or consisting of the sequence of SEQ ID NO: 13, optionally having up to 2 amino acid substitutions therefrom; ii. a HCDR2 comprising or consisting of the sequence of SEQ ID NO: 26, optionally having up to 2 amino acid substitutions therefrom; and ill. a HCDR3 comprising or consisting of the sequence of SEQ ID NO: 39, optionally having up to 2 amino acid substitutions therefrom; b) and a light chain variable region ( VL) comprising: i. a LCDR1 comprising or consisting of the sequence of SEQ ID NO: 52, optionally having up to 2 amino acid substitutions therefrom; ii. a LCDR2 comprising or consisting of the sequence of SEQ ID NO: 65, optionally having up to 2 amino acid substitutions therefrom; and ill. a LCDR3 comprising or consisting of the sequence of SEQ ID NO: 78, optionally having up to 2 amino acid substitutions therefrom.

[0316] The optional amino acid substitutions may be conservative substitutions.

[0317] The first antibody binding domain may comprise a VH comprising or consisting of the sequence of SEQ ID NO: 91 and a VL comprising or consisting of the sequence of SEQ ID NO: 104.

[0318] The first antibody binding domain may comprise a heavy chain comprising or consisting of the sequence of SEQ ID NO: 121 and a light chain comprising or consisting of the sequence SEQ ID NO: 147.

[0319] The first antibody binding domain may comprise a heavy chain comprising or consisting of the sequence of SEQ ID NO: 134 and a light chain comprising or consisting of the sequence SEQ ID NO: 147.

[0320] As will be understood, any of the first antibody binding domains comprising sequences from the anti-NKp46 antibody described herein as H13 / L13 may be suitably combined with any second antibody binding domain described herein. Any multivalent antibodies or antigen-binding fragments thereof comprising sequences from the anti-NKp46 antibody described herein as H13 / L13 may also be suitably combined with any of the IL-15 components (at least one IL-15 receptor alpha (CD215) or a functional fragment thereof and optionally an IL- 15 cytokine covalently or non-covalently associated) presented herein and the components arranged into any of the different arrangements and formats of immunoconjugate described herein.

[0321] TAA antibody components

[0322] In some embodiments, the second antibody binding domain of the multivalent antibody or antigen binding fragment thereof comprises sequences from an anti-TAA antibody such as an anti-HER2 antibody, an anti-EGFR antibody, an anti-CD19 antibody or an anti-CD20 antibody. In some embodiments, the second antibody binding domain of the multivalent antibody or antigen binding fragment thereof comprises sequences from an anti-TAA antibody, such as an anti-EGFRvI 11 antibody, an anti- GD2 antibody, an anti-PD-Ll antibody, or an anti-GPC3 antibody.

[0323] The second antibody binding domain may specifically bind to HER2 and comprise: a) a heavy chain variable region (VH) comprising i) a HCDR1 comprising or consisting of the sequence of SEQ ID NO: 330, optionally having up to 2 amino acid substitutions therefrom; ii) a HCDR2 comprising or consisting of the sequence of SEQ ID NO: 331, optionally having up to 2 amino acid substitutions therefrom; and ill) a HCDR3 comprising or consisting of the sequence of SEQ ID NO: 332, optionally having up to 2 amino acid substitutions therefrom; b) and a light chain variable region ( VL) comprising: i) a LCDR1 comprising or consisting of the sequence of SEQ ID NO: 333, optionally having up to 2 amino acid substitutions therefrom; ii) a LCDR2 comprising or consisting of the sequence of SEQ ID NO: 334, optionally having up to 2 amino acid substitutions therefrom; and ill) a LCDR3 comprising or consisting of the sequence of SEQ ID NO: 335, optionally having up to 2 amino acid substitutions therefrom; optionally wherein the optional amino acid substitutions are conservative substitutions.

[0324] The second antibody binding domain may specifically bind to HER2 and comprises a VH comprising or consisting of at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 95%, at least 97%, at least 98% or at least 99% identity to a sequence of SEQ ID NO: 304 and a VH domain comprising or consisting of at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 95%, at least 97%, at least 98% or at least 99% identity to a sequence of SEQ ID NO: 305.

[0325] The second antibody binding domain may specifically bind to HER2 and comprises a VH comprising or consisting of the sequence of SEQ ID NO: 304 and a VL domain comprising or consisting of the sequence of SEQ ID NO: 305. The second antibody binding domain may specifically bind to EGFR and comprises a VH comprising or consisting of the sequence of SEQ ID NO: 340 and a VL domain comprising or consisting of the sequence of SEQ ID NO: 341.

[0326] The second antibody binding domain may specifically bind to EGFRvlll and comprises a VH comprising or consisting of the sequence of SEQ ID NO: 342 and a VL domain comprising or consisting of the sequence of SEQ ID NO: 343.

[0327] The second antibody binding domain may specifically bind to GD2 and comprises a VH comprising or consisting of the sequence of SEQ ID NO: 344 and a VL domain comprising or consisting of the sequence of SEQ ID NO: 345.

[0328] The second antibody binding domain may specifically bind to PD-L1 and comprises a VH comprising or consisting of the sequence of SEQ ID NO: 346 and a VL domain comprising or consisting of the sequence of SEQ ID NO: 347.

[0329] The second antibody binding domain may specifically bind to CD19 and comprises a VH comprising or consisting of the sequence of SEQ ID NO: 348 and a VL domain comprising or consisting of the sequence of SEQ ID NO: 349.

[0330] The second antibody binding domain may specifically bind to CD20 and comprises a VH comprising or consisting of the sequence of SEQ ID NO: 350 and a VL domain comprising or consisting of the sequence of SEQ ID NO: 351.

[0331] The second antibody binding domain may specifically bind to GPC3 and comprises a VH comprising or consisting of the sequence of SEQ ID NO: 352 and a VL domain comprising or consisting of the sequence of SEQ ID NO: 353.

[0332] These anti TAA components (whether described by CDR sequence, by VH / VL sequence, by heavy / light chain sequence or otherwise) can be paired with a first antibody binding domain described herein, such as an anti- NKG2D antibody binding domain.

[0333] Competitive binding Immunoconjugates of the invention may compete for binding to NKG2D, NKp30, NKp46, NKp44 and DNAM-1 with any of the anti- NKG2D, NKp30, NKp46, NKp44 and DNAM-1 antibody binding domains described herein. Immunoconjugates of the invention may compete for binding to human NKG2D with any of the anti-NKG2D antibody binding domains described herein. Immunoconjugates of the invention may compete for binding to MICA / MICB with any of the anti-NKG2D antibody binding domains described herein.

[0334] The immunoconjugates may comprise a first antibody binding domain which competes with the antibody 21F2 for binding to human NKG2D.

[0335] The immunoconjugates may comprise a first antibody binding domain competes with the antibody 21F2 for binding to MICA or MICB.

[0336] The immunoconjugates may comprise a first antibody binding domain competes with the antibody 21F2 for binding to human NKG2D and MICA / MICB. Such immunoconjugates may "epitope" bin with antibody 21F2 when competitive immunoassays are undertaken to determine the binding profile of immunoconjugates as provided herein to NKG2D and / or MICA / MICB. Provided herein are immunoconjugates which "bind to essentially the same epitope or determinant as" as antibody 21F2. This means that the immunoconjugates as provided herein "compete" with antibody 21F2 for NKG2D molecules and / or MICA / MICB molecules.

[0337] Competition may be determined by surface plasmon resonance (SPR), ELISA, homogenous time resolved fluorescence (HTRF), or by fluorescence activated cell sorting (FACS), such techniques being readily apparent to the skilled person. Such competition may be due, for example, to the antibodies or fragments binding to identical or overlapping epitopes of NKG2D.

[0338] Hence such anti-NKG2D antibodies for incorporation into immunoconjugates as provided herein can be identified based on their ability to cross-compete with 21F2 in standard hNKG2D and / or MICA / MICB binding assays as described herein. The ability of a test antibody to inhibit the binding of 21F2 to hNKG2D and / or MICA / B demonstrates that the test antibody can compete 21F2 for binding and thus can bind to the same epitope or essentially the same epitope on hNKG2D and or MICA / B as 21F2. In a preferred embodiment, the antibody that binds to the same epitope on hNKG2D and / or MICA / B as 21F2 and which is incorporated into an immunoconjugate as provided herein is a human monoclonal antibody.

[0339] IL-15 components The immunoconjugates of the invention comprise an "IL-15 component" (also referred to as IL-15 polypeptide) which comprises at least one IL-15 receptor alpha (CD215) or a functional fragment thereof covalently linked to at least one C-terminus of the Fc domain. Preferably, the IL-15 receptor alpha (CD215) or a functional fragment thereof refers to the IL-15 receptor alpha (CD215) sushi domain, as defined herein.

[0340] As described herein it has been found an IL-15 cytokine may be part of the immunocytokine or may be expressed "in trans" as a separate polypeptide and associated non-covalently with the immunocytokine. The IL-15 component may also comprise a human IL-15 cytokine covalently or non-covalently associated with the IL-15 receptor alpha (CD215) or a functional fragment thereof. The term "IL-15 component" therefore encompasses at least the following configurations: i) one IL-15 receptor alpha (CD215) or a functional fragment thereof (preferably a IL-15 receptor alpha (CD215) sushi domain) covalently linked to the C-terminus of a first or second chain of the Fc domain, with no IL-15 cytokine covalently or non-covalently associated with the IL-15 receptor alpha (CD215) or a functional fragment thereof; ii) a first IL-15 receptor alpha (CD215) or a functional fragment thereof (preferably a IL-15 receptor alpha (CD215) sushi domain) covalently linked to the C-terminus of a first chain of the Fc domain, and a second IL-15 receptor alpha (CD215) or a functional fragment thereof (preferably a IL-15 receptor alpha (CD215) sushi domain) covalently linked to the C-terminus of a second chain of the Fc domain, with no IL-15 cytokines covalently or non-covalently associated with the first or second IL-15 receptor alpha (CD215) or functional fragments thereof; ill) one IL-15 receptor alpha (CD215) or a functional fragment thereof (preferably a IL-15 receptor alpha (CD215) sushi domain) covalently linked to the C-terminus of a first or second chain of the Fc domain, and an IL-15 cytokine covalently linked to the IL-15 receptor alpha (CD215) or a functional fragment thereof; iv) a first IL-15 receptor alpha (CD215) or a functional fragment thereof (preferably a IL-15 receptor alpha (CD215) sushi domain) covalently linked to the C-terminus of a first chain of the Fc domain and a first IL-15 cytokine covalently linked to the first IL-15 receptor alpha (CD215) or a functional fragment thereof, and a second IL-15 receptor alpha (CD215) or a functional fragment thereof (preferably a IL-15 receptor alpha (CD215) sushi domain) covalently linked to the C-terminus of a second chain of the Fc domain and a second IL-15 cytokine covalently linked to the second IL-15 receptor alpha (CD215) or a functional fragment thereof; v) one IL-15 receptor alpha (CD215) or a functional fragment thereof (preferably a IL-15 receptor alpha (CD215) sushi domain) covalently linked to the C-terminus of a first or second chain of the Fc domain, and an IL-15 cytokine non-covalently associated with the IL-15 receptor alpha (CD215) or a functional fragment thereof; vi) a first IL-15 receptor alpha (CD215) or a functional fragment thereof (preferably a IL-15 receptor alpha (CD215) sushi domain) covalently linked to the C-terminus of a first chain of the Fc domain and a first IL-15 cytokine non-covalently associated with the first IL-15 receptor alpha (CD215) or a functional fragment thereof, and a second IL-15 receptor alpha (CD215) or a functional fragment thereof (preferably a IL-15 receptor alpha (CD215) sushi domain) covalently linked to the C- terminus of a second chain of the Fc domain and a second IL-15 cytokine non-covalently associated with the second IL-15 receptor alpha (CD215) or a functional fragment thereof.

[0341] As will be understood, any of the various IL-15 components presented herein may be suitably combined with any of the multivalent antibodies or antigen-binding fragments thereof and the components arranged into the different arrangements and formats of immunoconjugates described herein.

[0342] IL-15 receptor alpha (CD215)

[0343] The term "IL-15 receptor alpha" as used herein refers to contiguous sequence that is at least about 90%, at least about 91%, at least about 92%, at least about 93%, at least about 94%, at least about 95% or at least about 96% identical to the equivalent portion of human IL-15 receptor alpha sequence of SEQ ID NO: 148 to which the contiguous sequence relates to. Such IL-15 receptor alpha polypeptides as defined herein may or may not also contain additional non-IL-15 receptor alpha sequence located or fused either N-terminal or C-terminal to the region homologous to human IL-15 receptor alpha. Preferably the IL-15 receptor alpha (CD215) is human IL-15 receptor alpha (CD215). The IL-15 receptor alpha (CD215) may comprise or consist of a sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 95%, at least 97%, at least 98% or at least 99% identity to SEQ ID NO: 148. The IL-15 receptor alpha (CD215) portion of the IL-15 component may comprise or consist of SEQ ID NO: 148.

[0344] The IL-15 receptor alpha (CD215) fragment(s) may comprise up to 100 consecutive amino acids of the IL-15 receptor alpha (CD215) sequence and the up to 100 consecutive amino acids comprises the IL-15 receptor alpha (CD215) sushi domain. l.The IL-15 receptor alpha (CD215) fragment(s) may comprise less than 73 consecutive amino acids of the IL-15 receptor alpha (CD215) sequence and comprise the IL-15 receptor alpha (CD215) sushi domain. Preferably the IL-15 receptor alpha sequence comprises a minimum of the human IL-15 receptor alpha "sushi domain". The term "IL-15 receptor alpha (CD215) sushi domain" or "sushi domain" refers to contiguous sequence that is at least about 90%, at least about 91%, at least about 92%, at least about 93%, at least about 94%, at least about 95% or at least about 96% identical to the equivalent portion of IL-15 sushi domain as defined in SEQ ID NO: 149, SEQ ID NO: 150, SEQ ID NO: 263 or SEQ ID NO: 264. Generally, the sushi domain refers to a domain beginning at the first cysteine residue (Cl) after the signal peptide of IL-15Ra, and ending at the fourth cysteine residue (C4) after said signal peptide. SEQ ID NO: 263 refers to this "core sushi domain" defined as including the 4 core cysteines (CYS3 to CYS63 of SEQ ID NO: 148 inclusive). SEQ ID NO: 150 refers to an "extended" sushi domain including an additional hinge region. Preferably the IL-15 receptor alpha sequence within the IL-15 polypeptide includes the IL-15 receptor alpha "sushi domain", preferably the human IL-15 receptor alpha sushi domain. Such "sushi domains" as defined herein may or may not also contain additional IL-15 receptor alpha sequence located either N-terminal or C-terminal to said sushi domain.

[0345] The IL-15 receptor alpha (CD215) sushi domain may comprise or consist of a sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 95%, at least 97%, at least 98% or at least 99% identity to a sequence selected from the group consisting of SEQ ID NOs: 149, 150, 263 and 264, preferably SEQ ID NO: 263. The IL-15 receptor alpha (CD215) sushi domain may comprise or consist of a sequence selected from the group consisting of SEQ ID NOs: 149, 150, 263 and 264. Preferably the IL-15 receptor alpha (CD215) sushi domain comprises or consists of the sequence SEQ ID NO: 263.

[0346] The IL-15 receptor alpha (CD215) or a functional fragment thereof may be covalently linked to the C-terminus of the Fc domain via direct fusion. The at least one IL-15 receptor alpha (CD215) or a functional fragment thereof may be covalently linked to the Fc domain via a linker, referred to herein as "linker 1".

[0347] Linker 1

[0348] The linker may be a peptide linker. Preferably the linker is flexible. Flexible linkers allow the joined domains a degree of movement which can play a key role in the function of the fused domains. The linker may be a peptide linker, optionally from about 1 to about 60 amino acid residues in length. The linker may be a TVAAPS linker, for example as shown in SEQ ID NO:184. The linker may be a ASTKGPS linker, for example as shown in SEQ ID NO:185. GlySer linkers are known in the art and may be used. For example, linkers may include those comprising or consisting of glycine and serine, for example multiple n repeats of the formulae [GGGGS]nX, or [GGGS]nX, or [GGS]nX, wherein n is typically between 1-6 and X is G or is absent. The linker may comprise or consist of the sequence [ [G]mS]nX, wherein m is from 2 to 4, n is from 1 to 6 and X is G or is absent. The linker may comprise or consist of glycine and serine residues, and optionally the linker comprises more glycine than serine residues. The linker may comprise or consist of glycine and serine residues in a ratio of from about 5:1 to about 2:1. The linker may comprise or consist of glycine and serine residues in a ratio of about 5:1. The linker may comprise or consist of about 80% glycine and about 20% serine residues. The linker joining the C- terminus of the Fc domain to the N-terminus of the IL-15 receptor alpha (CD215) or a functional fragment thereof may be greater than 30 amino acids in length. The linker joining the C-terminus of the Fc domain to the N-terminus of the IL-15 receptor alpha (CD215) or a functional fragment thereof may be between 30 and 60 amino acids in length. The linker joining the C-terminus of the Fc domain to the N-terminus of the IL-15 receptor alpha (CD215) or a functional fragment thereof may comprise or consist of the sequence of any of SEQ ID NOs: 182 to 187, 201, 204 to 205 and 265 to 268. Preferably the linker joining the C-terminus of the Fc domain to the N-terminus of the IL-15 receptor alpha (CD215) or a functional fragment thereof comprises or consists of the sequence of SEQ ID NO: 182. Typically, the length and sequence of such linkers can be optimised empirically. Such linkers can also incorporate alternate or additional amino acids. It also well recognized in the art that other synthetic or naturally ordered amino acid sequence combination are able to operate as flexible linkers.

[0349] IL- 15

[0350] The term "interleukin-15" or "IL-15" or "IL-15 cytokine" as used herein, refers to any native IL-15 polypeptide from any vertebrate source, including mammals such as primates (e.g. humans) and rodents (e.g., mice and rats), unless otherwise indicated. The term encompasses unprocessed IL-15 as well as any form of IL-15 that results from processing in the cell. The term also encompasses naturally occurring variants of IL-15, e.g. splice variants or allelic variants. The amino acid sequence of an exemplary mature human IL-15 cytokine is shown in SEQ ID NO: 151. SEQ ID NO: 152 provides the sequence of an IL-15 signal peptide. SEQ ID NO: 153 provides the sequence of an IL-15 pro-peptide. Unprocessed human IL-15 additionally comprises an N- terminal amino acid signal peptide having the sequence typically absent in the mature IL-15 molecule.

[0351] The IL-15 cytokine may comprise or consist of a sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 95%, at least 97%, at least 98% or at least 99% identity to a sequence selected from the group consisting of SEQ ID NOs: 151 to 153 and 285. The IL-15 cytokine may comprise or consist of a sequence selected from the group consisting of SEQ ID NOs: 151 to 153 and 285. Preferably the IL-15 cytokine is human IL-15 (hlL-15) cytokine or a variant or fragment thereof. The term "human IL-15" as used herein refers to contiguous sequence that is at least about 90%, at least about 91%, at least about 92%, at least about 93%, at least about 94%, at least about 95% or at least about 96% identical to the equivalent portion of human IL-15 sequence of SEQ ID NO: 151 to which the contiguous sequence relates to. Particularly, the sequence identity is at least about 95%, more particularly at least about 96%. The human IL-15 component may comprise a full-length, mature IL-15 polypeptide. Such human IL-15 components as defined herein may or may not also contain additional non-IL-15 cytokine sequence located or fused either N- terminal or C-terminal.

[0352] In embodiments when an IL-15 cytokine is covalently joined to the IL-15 receptor alpha (CD215) or functional fragment thereof, the immunoconjugate may comprising at least one human IL-15 cytokine or a functional fragment thereof covalently linked to the C-terminus of at least one IL-15 receptor alpha (CD215) or functional fragment thereof. The immunoconjugate provided may comprise a first human IL- 15 cytokine or a functional fragment thereof covalently linked to the C-terminus of a first IL-15 receptor alpha (CD215) or functional fragment thereof and a second human IL- 15 cytokine or a functional fragment thereof covalently linked to the C-terminus of a second IL-15 receptor alpha (CD215) or functional fragment thereof. In some embodiments IL- 15 cytokine and the IL-15 receptor alpha (CD215) or functional fragment thereof are directly fused to each other. In some embodiments the IL-15 cytokine and the IL-15 receptor alpha (CD215) or functional fragment thereof are joined by a linker (linker 2).

[0353] Linker 2

[0354] The linker may be a peptide linker. Preferably the linker is flexible. Flexible linkers allow the joined domains a degree of movement which can play a key role in the function of the fused domains. The linker may be a peptide linker, optionally from about 1 to about 60 amino acid residues in length. The linker may be a TVAAPS linker, for example as shown in SEQ ID NO:184. The linker may be a ASTKGPS linker, for example as shown in SEQ ID NO:185. GlySer linkers are known in the art and may be used. For example, linkers may include those comprising or consisting of glycine and serine, for example multiple n repeats of the formulae [GGGGS]nX, or [GGGS]nX, or [GGS]nX, wherein n is typically between 1-6 and X is G or is absent. The linker may comprise or consist of the sequence [ [G]mS]nX, wherein m is from 2 to 4, n is from 1 to 6 and X is G or is absent. The linker may comprise or consist of glycine and serine residues, and optionally the linker comprises more glycine than serine residues. The linker may comprise or consist of glycine and serine residues in a ratio of from about 5:1 to about 2:1. The linker may comprise or consist of glycine and serine residues in a ratio of about 5:1. The linker may comprise or consist of about 80% glycine and about 20% serine residues. The linker joining the N- terminus of the IL-15 cytokine to the C-terminus of IL-15 receptor alpha (CD215) or a functional fragment thereof may preferably be at least 30 amino acids in length. The linker joining the N-terminus of the IL-15 cytokine to the C-terminus of IL-15 receptor alpha (CD215) or a functional fragment thereof may be from 30 to 60 amino acids in length. The linker joining the N-terminus of the IL-15 cytokine to the C-terminus of IL-15 receptor alpha (CD215) or a functional fragment thereof may comprise or consist of the sequence of any of SEQ ID NOs: 182 to 187, 201, 204 to 205 and 265 to 268. The linker joining the N-terminus of the IL-15 cytokine to the C-terminus of IL-15 receptor alpha (CD215) or a functional fragment thereof may comprise or consist of the sequence of any of SEQ ID NOs: 265 to 268. Preferably the linker joining the N-terminus of the IL-15 cytokine to the C-terminus of IL-15 receptor alpha (CD215) or a functional fragment thereof (preferably the IL-15 receptor alpha sushi domain) comprises or consists of the sequence of SEQ ID NO: 265. Typically, the length and sequence of such linkers can be optimised empirically. Such linkers can also incorporate alternate or additional amino acids. It also well recognized in the art that other synthetic or naturally ordered amino acid sequence combination are able to operate as flexible linkers.

[0355] The IL-15 component may be an IL-15 superagonist. The term "IL-15 superagonist" as referred to herein refers to a sub-set of IL-15 components with enhanced or increased biological activity compared to wildtype IL-15 alone. An "IL-15 superagonist" as used herein has a higher agonistic activity compared to wild-type IL-15. This is also sometimes also referred to as hyperagonism. Preferably the IL-15 superagonist is a human IL-15 cytokine fused to the sushi domain of the IL-15 receptor alpha.

[0356] The immunoconjugate may comprise: i) an IL-15 receptor alpha (CD215) sushi domain comprising or consisting of the sequence of SEQ ID NO: 263, covalently linked to the C-terminus of a first or second chain of the Fc domain via a linker comprising or consisting of the sequence of SEQ ID NO: 182, with no IL-15 cytokine covalently or non-covalently associated with the IL-15 receptor alpha sushi domain; ii) a first IL-15 receptor alpha (CD215) sushi domain comprising or consisting of the sequence of SEQ ID NO: 263 covalently linked to the C-terminus of a first chain of the Fc domain via a linker comprising or consisting of the sequence of SEQ ID NO: 182, and a IL-15 receptor alpha (CD215) sushi domain comprising or consisting of the sequence of SEQ ID NO: 263 covalently linked to the C-terminus of a second chain of the Fc domain optionally via a linker comprising or consisting of the sequence of SEQ ID NO: 182, with no IL-15 cytokines covalently or non-covalently associated with the first or second IL-15 receptor alpha (CD215) or functional fragments thereof; ill) an IL-15 receptor alpha (CD215) sushi domain comprising or consisting of the sequence of SEQ ID NO: 263, covalently linked via direct fusion (no linker 1) to the C-terminus of a first or second chain of the Fc domain, with no IL-15 cytokine covalently or non-covalently associated with the IL-15 receptor alpha sushi domain; iv) a first IL-15 receptor alpha (CD215) sushi domain comprising or consisting of the sequence of SEQ ID NO: 263 covalently linked via direct fusion (no linker 1) to the C-terminus of a first chain of the Fc domain, and a IL-15 receptor alpha (CD215) sushi domain comprising or consisting of the sequence of SEQ ID NO: 263 covalently linked via direct fusion (no linker 1) to the C-terminus of a second chain of the Fc domain, with no IL-15 cytokines covalently or non-covalently associated with the first or second IL-15 receptor alpha (CD215) or functional fragments thereof.

[0357] The immunoconjugate may comprise: v) an IL-15 receptor alpha (CD215) sushi domain comprising or consisting of the sequence of SEQ ID NO: 263 covalently linked to the C-terminus of a first or second chain of the Fc domain via a linker comprising or consisting of the sequence of SEQ ID NO: 182, and a human IL-15 cytokine comprising or consisting of the sequence of SEQ ID NO: 151 covalently linked to the IL-15 receptor alpha (CD215) sushi domain via a linker comprising or consisting of the sequence of SEQ ID NO: 265; vi) a first IL-15 receptor alpha (CD215) sushi domain comprising or consisting of the sequence of SEQ ID NO: 263 covalently linked to the C-terminus of a first chain of the Fc domain via a linker comprising or consisting of the sequence of SEQ ID NO: 182 and a first human IL-15 cytokine comprising or consisting of the sequence of SEQ ID NO: 151 covalently linked to the first IL-15 receptor alpha (CD215) sushi domain via a linker comprising or consisting of the sequence of SEQ ID NO: 265, and a second IL-15 receptor alpha (CD215) sushi domain comprising or consisting of the sequence of SEQ ID NO: 263 covalently linked to the C-terminus of a second chain of the Fc domain via a linker comprising or consisting of the sequence of SEQ ID NO: 182 and a second human IL-15 cytokine comprising or consisting of the sequence of SEQ ID NO: 151 covalently linked to the second IL-15 receptor alpha (CD215) sushi domain via a linker comprising or consisting of the sequence of SEQ ID NO: 265: vii) an IL-15 receptor alpha (CD215) sushi domain comprising or consisting of the sequence of SEQ ID NO: 263 covalently linked to the C-terminus of a first or second chain of the Fc domain via direct fusion (no linker 1), and a human IL-15 cytokine comprising or consisting of the sequence of SEQ ID NO: 151 covalently linked to the IL-15 receptor alpha (CD215) sushi domain via a linker comprising or consisting of the sequence of SEQ ID NO: 265; viii) a first IL-15 receptor alpha (CD215) sushi domain comprising or consisting of the sequence of SEQ ID NO: 263 covalently linked to the C-terminus of a first chain of the Fc domain via direct fusion (no linker 1) and a first human IL-15 cytokine comprising or consisting of the sequence of SEQ ID NO: 151 covalently linked to the first IL-15 receptor alpha (CD215) sushi domain via a linker comprising or consisting of the sequence of SEQ ID NO: 265, and a second IL-15 receptor alpha (CD215) sushi domain comprising or consisting of the sequence of SEQ ID NO: 263 covalently linked to the C-terminus of a second chain of the Fc domain via direct fusion (no linker 1) and a second human IL-15 cytokine comprising or consisting of the sequence of SEQ ID NO: 151 covalently linked to the second IL-15 receptor alpha (CD215) sushi domain via a linker comprising or consisting of the sequence of SEQ ID NO: 265.

[0358] The immunoconjugate may comprise: ix) an IL-15 receptor alpha (CD215) sushi domain comprising or consisting of the sequence of SEQ ID NO: 263, covalently linked to the C-terminus of a first or second chain of the Fc domain via a linker comprising or consisting of the sequence of SEQ ID NO: 182, and a human IL-15 cytokine comprising or consisting of the sequence of SEQ ID NO: 151 non-covalently associated with the IL- 15 receptor alpha (CD215) sushi domain; x) a first IL-15 receptor alpha (CD215) sushi domain comprising or consisting of the sequence of SEQ ID NO: 263 covalently linked to the C-terminus of a first chain of the Fc domain via a linker comprising or consisting of the sequence of SEQ ID NO: 182 and a first human IL-15 cytokine comprising or consisting of the sequence of SEQ ID NO: 151 non- covalently associated with the first IL-15 receptor alpha (CD215) sushi, and a second IL-15 receptor alpha (CD215) sushi domain comprising or consisting of the sequence of SEQ ID NO: 263 covalently linked to the C-terminus of a second chain of the Fc domain via a linker comprising or consisting of the sequence of SEQ ID NO: 182 and a second human IL-15 cytokine comprising or consisting of the sequence of SEQ ID NO: 151 non-covalently associated with the second IL-15 receptor alpha (CD215) sushi domain; xi) an IL-15 receptor alpha (CD215) sushi domain comprising or consisting of the sequence of SEQ ID NO: 263, covalently linked to the C-terminus of a first or second chain of the Fc domain via direct fusion (no linker 1), and a human IL-15 cytokine comprising or consisting of the sequence of SEQ ID NO: 151 non-covalently associated with the IL-15 receptor alpha (CD215) sushi domain; xii) a first IL-15 receptor alpha (CD215) sushi domain comprising or consisting of the sequence of SEQ ID NO: 263 covalently linked to the C-terminus of a first chain of the Fc domain via direct fusion (no linker 1) and a first human IL-15 cytokine comprising or consisting of the sequence of SEQ ID NO: 151 non- covalently associated with the first IL-15 receptor alpha (CD215) sushi, and a second IL-15 receptor alpha (CD215) sushi domain comprising or consisting of the sequence of SEQ ID NO: 263 covalently linked to the C-terminus of a second chain of the Fc domain via direct fusion (no linker 1) and a second human IL-15 cytokine comprising or consisting of the sequence of SEQ ID NO: 151 non-covalently associated with the second IL-15 receptor alpha (CD215) sushi domain. The IL-15 component may comprise or consist of a sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 95%, at least 97%, at least 98% or at least 99% identity to a sequence selected from the group consisting of SEQ ID NOs: 154, 155, 206, 207, 327, 328 and 329, preferably SEQ ID NO: 327. The IL-15 component may comprise or consist of a sequence selected from the group consisting of SEQ ID NOs: 154, 155, 206, 207, 327, 328 and 329. Preferably the IL-15 polypeptide may comprise or consist of the sequence of SEQ ID NO: 327, which comprises the sushi domain of SEQ ID NO: 149, the linker of SEQ ID NO: 265 and the IL-15 cytokine of SEQ ID NO: 151. The IL-15 component may comprise or consist of the sequence of SEQ ID NO: 154, which comprises the sushi domain of SEQ ID NO: 149, the linker of SEQ ID NO: 183 and the IL-15 cytokine of SEQ ID NO: 151. The IL-15 component may comprise or consist of SEQ ID NO: 206. This IL-15 component comprises a sushi domain (SEQ ID NO: 149), a linker (SEQ ID NO: 184) and an IL-15 cytokine (SEQ ID NO: 151). The IL-15 polypeptide may comprise or consist of SEQ ID NO: 207. This IL-15 component comprises a sushi domain (SEQ ID NO: 149), a linker (SEQ ID NO: 201 and / or 183) and an IL-15 cytokine (SEQ ID NO: 151). The IL-15 polypeptide may comprise or consist of SEQ ID NO: 328. This IL-15 component comprises a sushi domain (SEQ ID NO: 264), a linker (SEQ ID NO: 265) and an IL-15 cytokine (SEQ

[0359] ID NO: 151). The IL-15 polypeptide may comprise or consist of SEQ ID NO: 329. This IL-15 component comprises a sushi domain (SEQ ID NO: 150), a linker (SEQ ID NO: 265) and an IL-15 cytokine (SEQ ID NO: 151).

[0360] Specific immunoconjugates

[0361] A non-limiting summary of some of the immunoconjugates provided herein is provided below in a list of numbered statements. The present invention explicitly provides each of statements 1 to 179 in combination with any of the features of embodiments 1 to 101.

[0362] Specific immunoconjugates - 2+1+1 (4 chain)

[0363] The immunoconjugates of the invention may be formatted in a "2+1+1" format as defined herein and shown in Figure 1(A). These immunoconjugates comprise: a. a multivalent antibody or antigen-binding fragment thereof comprising: i. two antibody binding domains wherein:

[0364] 1. the first antibody binding domain specifically binds to a first target antigen selected from the group consisting of NKG2D, NKp30, NKp46, NKp44 and DNAM-1; and

[0365] 2. the second antibody binding domain specifically binds to a second, different target antigen, optionally a TAA such as HER2, EGFR, CD19 or CD20; ii. a human immunoglobulin Fc domain comprising:

[0366] 1. a first chain comprising in an N- to C- terminal direction a CH2 domain and a CH3 domain; and

[0367] 2. a second chain comprising in an N- to C- terminal direction a CH2 domain and a CH3 domain; and c. two IL-15 receptor alpha (CD215) or a functional fragments thereof covalently linked to the C- termini ofthe Fc domain (optionally via a linker 1) and two human IL-15 cytokines covalently linked to the C-termini of the IL-15 receptor alpha (CD215) or functional fragments thereof (optionally via a linker 2), wherein i. the first IL-15 cytokine is covalently linked to the C-terminus of the first IL-15 receptor alpha (CD215) orfunctional fragmentthereof and the first IL-15 receptor alpha (CD215) or a functional fragment thereof is covalently linked to the C-terminus of the first chain of the Fc domain; and ii. the second IL-15 cytokine is covalently linked to the C-terminus of the second IL-15 receptor alpha (CD215) or functional fragment thereof and the second IL-15 receptor alpha (CD215) or a functional fragment thereof is covalently linked to the C-terminus of the second chain of the Fc domain.

[0368] Each of the components of the 2+1+1 immunocytokine may be as described herein. Preferably the first antibody binding domain binds NKG2D and the second antigen binds a TAA. Preferably, the first antibody binding domain comprises sequences from the anti-NKG2D antibody described herein as H6 / L6 (21F2). Preferably, the CH3 domain of the first chain comprises or consists of the sequence of SEQ ID NO: 270 (knob) and the CH3 domain of the second chain comprises or consists of the sequence of SEQ ID NO: 271 (hole). Preferably no linker 1 is present. If linker 1 is present, preferably it comprises or consists of the sequence of SEQ ID NO: 182. Preferably the IL-15 receptor alpha (CD215) or a functional fragment thereof are human IL-15 receptor alpha (CD215) sushi domains comprising the sequence of SEQ ID NO: 263, for example SEQ ID NO: 149. Preferably linker 2 comprises or consists of the sequence of SEQ ID NO: 265. Preferably the human IL-15 cytokines comprise or consist of the sequence of SEQ ID NO: 151.

[0369] As shown in Figure 1(C), in the immunoconjugate formats described herein:

[0370] • the immunoglobulin heavy chain of the first antibody binding domain of the multivalent antibody is referred to as the first polypeptide chain

[0371] • the immunoglobulin light chain of the first antibody binding domain of the multivalent antibody is referred to as the second polypeptide chain. • the immunoglobulin heavy chain of the second antibody binding domain of the multivalent antibody is referred to as the third polypeptide chain

[0372] • the immunoglobulin light chain of the second antibody binding domain of the multivalent antibody is referred to as the fourth polypeptide chain

[0373] The first polypeptide (heavy chain) and second polypeptide (light chain) forms a first subunit. The third polypeptide (heavy chain) and fourth polypeptide (light chain) forms a second subunit. This then heterodimerizes to form the final immunoconjugate comprising two said subunits and thus a total of four polypeptide chains. Said heterodimerization may occur via one of the mechanisms for engineering heterodimerization described herein, preferably via a KiH method. The immunoconjugates can therefore be described as dimers, with one monomer subunit of the dimer comprising the first polypeptide chain and the second polypeptide chain and the second monomer subunit of the dimer comprising the third polypeptide chain and the fourth polypeptide chain. In these embodiments the immunoconjugate is considered heterodimeric. In some embodiments, the immunoconjugate may have been selectively purified in order to arrive at such a heterodimeric species and remove or reduce any unwanted fragments, higher order aggregates, and alternative homodimeric species that may be considered impurities. In some embodiments the heterodimeric immunoconjugate is the preferred species in a mixture that includes said impurities.

[0374] The anti-NKG2D antibody, anti-NKp30 antibody, anti-NKp46 antibody, anti-NKp44 antibody or anti-DNAM-1 antibody referred to in the immunoconjugate formats described below may be any of the antibodies Hl / Ll to H13 / L13, or could be another antibody against these targets known in the art.

[0375] The invention includes the following numbered statements:

[0376] Statement 1. The immunoconjugate may comprise: a) a first polypeptide chain comprising, in an N- to C- terminal direction: i. a heavy chain variable region (VH) of an anti-NKG2D antibody, an anti-NKp30 antibody, an anti-NKp46 antibody, an anti-NKp44 antibody or an anti-DNAM-1 antibody; ii. a human heavy chain constant region; ill. optionally a linker; iv. an IL-15 receptor alpha (CD215) or a functional fragment thereof; v. optionally a linker; and vi. an IL-15 cytokine; and b) a second polypeptide chain comprising, in an N- to C-terminal direction: i. a light chain variable region (VL) of an anti-NKG2D antibody, an anti-NKp30 antibody, an anti- NKp46 antibody, an anti-NKp44 antibody or an anti-DNAM-1 antibody; and ii. a human light constant region; and c) a third polypeptide chain comprising, in an N- to C-terminal direction i. a heavy chain variable region (VH) of an anti-TAA antibody; ii. a human heavy chain constant region; iii. optionally a linker; iv. an IL-15 receptor alpha (CD215) or a functional fragment thereof; v. optionally a linker; and vi. an IL-15 cytokine; and d) a fourth polypeptide chain comprising, in an N- to C-terminal direction: i. a light chain variable region (VL) of an anti-TAA antibody; and ii. a human light constant region.

[0377] Statement 2. The immunoconjugate may comprise: a) a first polypeptide chain comprising, in an N- to C- terminal direction: i) a heavy chain variable region (VH) of an anti-NKG2D antibody, an anti-NKp30 antibody, an anti-NKp46 antibody, an anti-NKp44 antibody or an anti-DNAM-1 antibody; ii) a human heavy chain constant region comprising a CH3 domain comprising one or more amino acid substitutions suitable for knobs-in-holes (KIH) dimerization with the CH3 domain of the third polypeptide chain; iii) optionally a linker; iv) an IL-15 receptor alpha (CD215) or a functional fragment thereof; v) optionally a linker; and vi) an IL-15 cytokine; and b) a second polypeptide chain comprising, in an N- to C-terminal direction: i) a light chain variable region (VL) of an anti-NKG2D antibody, an anti-NKp30 antibody, an anti- NKp46 antibody, an anti-NKp44 antibody or an anti-DNAM-1 antibody; and ii) a human light constant region; and c) a third polypeptide chain comprising, in an N- to C-terminal direction i) a heavy chain variable region (VH) of an anti-TAA antibody; ii) a human heavy chain constant region comprising a CH3 domain comprising one or more amino acid substitutions suitable for knobs-in-holes (KIH) dimerization with the CH3 domain of the first polypeptide chain; iii) optionally a linker; iv) an IL-15 receptor alpha (CD215) or a functional fragment thereof; v) optionally a linker; and vi) an IL-15 cytokine; and d) a fourth polypeptide chain comprising, in an N- to C-terminal direction: i) a light chain variable region (VL) of an anti-TAA antibody; and ii) a human light constant region.

[0378] Statement 3. The immunoconjugate may comprise: a) a first polypeptide chain comprising, in an N- to C- terminal direction: i) a heavy chain variable region (VH) of an anti-NKG2D antibody; ii) a human heavy chain constant region comprising a CH3 domain comprising one or more amino acid substitutions suitable for knobs-in-holes (KIH) dimerization with the CH3 domain of the third polypeptide chain; iii) optionally a linker; iv) an IL-15 receptor alpha (CD215) or a functional fragment thereof; v) optionally a linker; and vi) an IL-15 cytokine; and b) a second polypeptide chain comprising, in an N- to C-terminal direction: i) a light chain variable region (VL) of an anti-NKG2D antibody; and ii) a human light constant region; and c) a third polypeptide chain comprising, in an N- to C-terminal direction i. a heavy chain variable region (VH) of an anti-TAA antibody; ii. a human heavy chain constant region comprising a CH3 domain comprising one or more amino acid substitutions suitable for knobs-in-holes (KIH) dimerization with the CH3 domain of the first polypeptide chain; iii. optionally a linker; iv. an IL-15 receptor alpha (CD215) or a functional fragment thereof; v. optionally a linker; and vi. an IL-15 cytokine; and d) a fourth polypeptide chain comprising, in an N- to C-terminal direction: i. a light chain variable region (VL) of an anti-TAA antibody; and ii. a human light constant region.

[0379] Statement 4. The immunoconjugate may comprise: a) a first polypeptide chain comprising, in an N- to C- terminal direction: i. a heavy chain variable region (VH) of an anti-NKG2D antibody, an anti-NKp30 antibody, an anti-NKp46 antibody, an anti-NKp44 antibody or an anti-DNAM-1 antibody; ii. a human heavy chain constant region comprising a CH3 domain comprising or consisting of the sequence of SEQ ID NO: 270; iii. optionally a linker comprising or consisting of 5 amino acids or less; iv. an IL-15 receptor alpha (CD215) sushi domain comprising the sequence of SEQ ID NO: 263; v. a linker comprising or consisting of at least 30 amino acids; and vi. an IL-15 cytokine comprising or consisting of SEQ ID NO: 151; and b) a second polypeptide chain comprising, in an N- to C-terminal direction: i. a light chain variable region (VL) of an anti-NKG2D antibody, an anti-NKp30 antibody, an anti- NKp46 antibody, an anti-NKp44 antibody or an anti-DNAM-1 antibody; and ii. a human IgGl light constant region; and c) a third polypeptide chain comprising, in an N- to C-terminal direction i. a heavy chain variable region (VH) of an anti-TAA antibody; ii. a human heavy chain constant region comprising a CH3 domain comprising or consisting of SEQ ID NO: 271; iii. optionally a linker comprising or consisting of 5 amino acids or less; iv. an IL-15 receptor alpha (CD215) sushi domain comprising the sequence of SEQ ID NO: 263; v. optionally a linker comprising or consisting of at least 30 amino acids; and vi. an IL-15 cytokine comprising or consisting of SEQ ID NO: 151; and d) a fourth polypeptide chain comprising, in an N- to C-terminal direction: i. a light chain variable region (VL) of an anti-TAA antibody; and ii. a human IgGl light constant region.

[0380] Statement 5. The immunoconjugate may comprise: a) a first polypeptide chain comprising, in an N- to C- terminal direction: i. a heavy chain variable region (VH) of an anti-NKG2D antibody, an anti-NKp30 antibody, an anti-NKp46 antibody, an anti-NKp44 antibody or an anti-DNAM-1 antibody; ii. a human heavy chain constant region comprising a CH3 domain comprising or consisting of the sequence of SEQ ID NO: 270; iii. optionally a linker comprising or consisting of the sequence of SEQ ID NO: 182; iv. an IL-15 receptor alpha (CD215) sushi domain comprising the sequence of SEQ ID NO: 263; v. a linker comprising or consisting of the sequence of SEQ ID NO: 265; and vi. an IL-15 cytokine comprising or consisting of SEQ ID NO: 151; and b) a second polypeptide chain comprising, in an N- to C-terminal direction: i. a light chain variable region (VL) of an anti-NKG2D antibody, an anti-NKp30 antibody, an anti- NKp46 antibody, an anti-NKp44 antibody or an anti-DNAM-1 antibody; and ii. a human IgGl light constant region; and c) a third polypeptide chain comprising, in an N- to C-terminal direction i. a heavy chain variable region (VH) of an anti-TAA antibody; ii. a human heavy chain constant region comprising a CH3 domain comprising or consisting of SEQ ID NO: 271; iii. optionally a linker comprising or consisting of the sequence of SEQ ID NO: 182; iv. an IL-15 receptor alpha (CD215) sushi domain comprising the sequence of SEQ ID NO: 263; v. optionally a linker comprising or consisting of the sequence of SEQ ID NO: 265; and vi. an IL-15 cytokine comprising or consisting of SEQ ID NO: 151; and d) a fourth polypeptide chain comprising, in an N- to C-terminal direction: i. a light chain variable region (VL) of an anti-TAA antibody; and ii. a human IgGl light constant region.

[0381] Statement 6. The immunoconjugate may comprise: a) a first polypeptide chain comprising, in an N- to C- terminal direction: i. a heavy chain variable region (VH) of an anti-NKG2D antibody, an anti-NKp30 antibody, an anti-NKp46 antibody, an anti-NKp44 antibody or an anti-DNAM-1 antibody; ii. a human heavy chain constant region comprising or consisting of the sequence of SEQ ID NO: 314 or SEQ ID NO: 320; iii. optionally a linker comprising or consisting of the sequence of SEQ ID NO: 182; iv. an IL-15 receptor alpha (CD215) sushi domain comprising the sequence of SEQ ID NO: 263; v. a linker comprising or consisting of the sequence of SEQ ID NO: 265; and vi. an IL-15 cytokine comprising or consisting of SEQ ID NO: 151; and b) a second polypeptide chain comprising, in an N- to C-terminal direction: i. a light chain variable region (VL) of an anti-NKG2D antibody, an anti-NKp30 antibody, an anti- NKp46 antibody, an anti-NKp44 antibody or an anti-DNAM-1 antibody; and ii. a light constant region comprising or consisting of the sequence of SEQ ID NO: 310; and c) a third polypeptide chain comprising, in an N- to C-terminal direction i. a heavy chain variable region ( VH ) of an anti-TAA antibody; ii. a human heavy chain constant region comprising or consisting of the sequence of SEQ ID NO: 315 or SEQ ID NO: 321; iii. optionally a linker comprising or consisting of the sequence of SEQ ID NO: 182; iv. an IL-15 receptor alpha (CD215) sushi domain comprising the sequence of SEQ ID NO: 263; v. optionally a linker comprising or consisting of the sequence of SEQ ID NO: 265; and vi. an IL-15 cytokine comprising or consisting of SEQ ID NO: 151; and d) a fourth polypeptide chain comprising, in an N- to C-terminal direction: i. a light chain variable region (VL) of an anti-TAA antibody; and ii. a light constant region comprising or consisting of the sequence of SEQ ID NO: 310.

[0382] Statement 7. The immunoconjugate may comprise: a) a first polypeptide chain comprising, in an N- to C- terminal direction: i) a heavy chain variable region (VH) of an anti-NKG2D antibody, an anti-NKp30 antibody, an anti- NKp46 antibody, an anti-NKp44 antibody or an anti-DNAM-1 antibody; ii) a human heavy chain constant region comprising or consisting of the sequence of SEQ ID NO: 316 or SEQ ID NO: 322; iii) optionally a linker comprising or consisting of the sequence of SEQ ID NO: 182; iv) an IL-15 receptor alpha (CD215) sushi domain comprising the sequence of SEQ ID NO: 263; v) a linker comprising or consisting of the sequence of SEQ ID NO: 265; and vi) an IL-15 cytokine comprising or consisting of SEQ ID NO: 151; and b) a second polypeptide chain comprising, in an N- to C-terminal direction: i) a light chain variable region (VL) of an anti-NKG2D antibody, an anti-NKp30 antibody, an anti-NKp46 antibody, an anti-NKp44 antibody or an anti-DNAM-1 antibody; and ii) a light constant region comprising or consisting of the sequence of SEQ ID NO: 299; and c) a third polypeptide chain comprising, in an N- to C-terminal direction i) a heavy chain variable region (VH) of an anti-TAA antibody; ii) a human heavy chain constant region comprising or consisting of the sequence of SEQ ID NO: 317 or SEQ ID NO: 323; iii) optionally a linker comprising or consisting of the sequence of SEQ ID NO: 182; iv) an IL-15 receptor alpha (CD215) sushi domain comprising the sequence of SEQ ID NO: 263; v) optionally a linker comprising or consisting of the sequence of SEQ ID NO: 265; and vi) an IL-15 cytokine comprising or consisting of SEQ ID NO: 151; and d) a fourth polypeptide chain comprising, in an N- to C-terminal direction: i) a light chain variable region (VL) of an anti-TAA antibody; and ii) a light constant region comprising or consisting of the sequence of SEQ ID NO: 299.

[0383] Statement 8. The immunoconjugate may comprise: a) a first polypeptide chain comprising, in an N- to C- terminal direction: i. a heavy chain variable region (VH) of an anti-NKG2D antibody, an anti-NKp30 antibody, an anti- NKp46 antibody, an anti-NKp44 antibody or an anti-DNAM-1 antibody; ii. a human heavy chain constant region comprising or consisting of the sequence of SEQ ID NO: 318 or SEQ ID NO: 324; iii. optionally a linker comprising or consisting of the sequence of SEQ ID NO: 182; iv. an IL-15 receptor alpha (CD215) sushi domain comprising the sequence of SEQ ID NO: 263; v. a linker comprising or consisting of the sequence of SEQ ID NO: 265; and vi. an IL- 15 cytokine comprising or consisting of SEQ ID NO: 151; and b) a second polypeptide chain comprising, in an N- to C-terminal direction: i. a light chain variable region (VL) of an anti-NKG2D antibody, an anti-NKp30 antibody, an anti- NKp46 antibody, an anti-NKp44 antibody or an anti-DNAM-1 antibody; and ii. a light constant region comprising or consisting of the sequence of SEQ ID NO: 326; and c) a third polypeptide chain comprising, in an N- to C-terminal direction i. a heavy chain variable region (VH) of an anti-TAA antibody; ii. a human heavy chain constant region comprising or consisting of the sequence of SEQ ID NO: 319 or SEQ ID NO: 325; iii. optionally a linker comprising or consisting of the sequence of SEQ ID NO: 182; iv. an IL-15 receptor alpha (CD215) sushi domain comprising the sequence of SEQ ID NO: 263; v. optionally a linker comprising or consisting of the sequence of SEQ ID NO: 265; and vi. an IL-15 cytokine comprising or consisting of SEQ ID NO: 151; and d) a fourth polypeptide chain comprising, in an N- to C-terminal direction: i. a light chain variable region (VL) of an anti-TAA antibody; and ii. a light constant region comprising or consisting of the sequence of SEQ. ID NO: 326.

[0384] In any of the statements 1 to 42, the first and second polypeptide chains are covalently or non-covalently associated with each other such that each heavy chain (variable region) and each light chain (variable region) form a first antibody binding domain. The third and fourth polypeptide chains are covalently or non-covalently associated with each other such that each heavy chain (variable region) and each light chain (variable region) form a second antibody binding domain. The resulting first and second antibody binding domains are covalently or non-covalently associated with each other in an immunoglobulin-type format, thereby forming the immunoconjugate comprising the multivalent antibody or antigen binding fragment thereof.

[0385] NKG2D - 2+1+1 (4 chain)

[0386] Statement 9. The immunoconjugate may comprise: a) a first polypeptide chain comprising, in an N- to C- terminal direction: i. a heavy chain variable region ( VH ) of an anti-NKG2D antibody; ii. a human heavy chain constant region; iii. optionally a linker; iv. an IL-15 receptor alpha (CD215) or a functional fragment thereof; v. optionally a linker; and vi. an IL-15 cytokine; and b) a second polypeptide chain comprising, in an N- to C-terminal direction: i. a light chain variable region (VL) of an anti-NKG2D antibody; and ii. a human light constant region; and c) a third polypeptide chain comprising, in an N- to C-terminal direction i. a heavy chain variable region (VH) of an anti-TAA antibody; ii. a human heavy chain constant region; iii. optionally a linker; iv. an IL-15 receptor alpha (CD215) or a functional fragment thereof; v. optionally a linker; and vi. an IL-15 cytokine; and d) a fourth polypeptide chain comprising, in an N- to C-terminal direction: i. a light chain variable region (VL) of an anti-TAA antibody; and ii. a human light constant region. Statement 10. The immunoconjugate may comprise: a) a first polypeptide chain comprising, in an N- to C- terminal direction: i. a heavy chain variable region (VH) of any anti-NKG2D antibody described herein as Hl to H10; ii. a human heavy chain constant region; iii. optionally a linker; iv. an IL-15 receptor alpha (CD215) or a functional fragment thereof; v. optionally a linker; and vi. an IL-15 cytokine; and b) a second polypeptide chain comprising, in an N- to C-terminal direction: i. a light chain variable region (VL) of any anti-NKG2D antibody described herein as LI to LIO; and ii. a human light constant region; and c) a third polypeptide chain comprising, in an N- to C-terminal direction i. a heavy chain variable region (VH) of an anti-TAA antibody; ii. a human heavy chain constant region; iii. optionally a linker; iv. an IL-15 receptor alpha (CD215) or a functional fragment thereof; v. optionally a linker; and vi. an IL-15 cytokine; and d) a fourth polypeptide chain comprising, in an N- to C-terminal direction: i. a light chain variable region (VL) of an anti-TAA antibody; and ii. a human light constant region.

[0387] Statement 11. The immunoconjugate may comprise: a) a first polypeptide chain comprising, in an N- to C- terminal direction: i. a heavy chain variable region (VH) of an anti-NKG2D antibody comprising an HCDR1 comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 1 to 10 and optionally having up to 2 amino acid substitutions thereto, an HCDR2 comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 14 to 23 and optionally having up to 2 amino acid substitutions thereto, and an HCDR3 comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 1 to 36 and optionally having up to 2 amino acid substitutions thereto; ii. a heavy chain constant region comprising or consisting of a sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 95%, at least 97%, at least 98% or at least 99% identity to a sequence selected from the group consisting of SEQ ID NOs: 105, 106, 203 and 314 to 325; iii. optionally a linker; iv. an IL-15 receptor alpha (CD215) or a functional fragment thereof; v. optionally a linker; and vi. an IL-15 cytokine; and b) a second polypeptide chain comprising, in an N- to C-terminal direction: i. a a light chain variable region ( VL) of an anti-NKG2D antibody comprising an LCDR1 comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 40 to 49 and optionally having up to 2 amino acid substitutions thereto, an LCDR2 comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 53 to 62 and optionally having up to 2 amino acid substitutions thereto, and an LCDR3 comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 66 to 75 and optionally having up to 2 amino acid substitutions thereto; and ii. a light chain constant region comprising or consisting of a sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 95%, at least 97%, at least 98% or at least 99% identity to a sequence selected from the group consisting of SEQ ID NOs: 107, 108, 299, 310 and 326; and c) a third polypeptide chain comprising, in an N- to C-terminal direction i. a heavy chain variable region (VH) of an anti-TAA antibody; ii. a heavy chain constant region comprising or consisting of a sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 95%, at least 97%, at least 98% or at least 99% identity to a sequence selected from the group consisting of SEQ ID NOs: 105, 106, 203 and 314 to 325; iii. optionally a linker; iv. an IL-15 receptor alpha (CD215) or a functional fragment thereof; v. optionally a linker; and vi. an IL-15 cytokine; and d) a fourth polypeptide chain comprising, in an N- to C-terminal direction: i. a light chain variable region (VL) of an anti-TAA antibody; and ii. a light chain constant region comprising or consisting of a sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 95%, at least 97%, at least 98% or at least 99% identity to a sequence selected from the group consisting of SEQ ID NOs: 107, 108, 299, 310 and 326.

[0388] The optional amino acid substitutions may be conservative substitutions.

[0389] Statement 12. The immunoconjugate may comprise: a) a first polypeptide chain comprising, in an N- to C- terminal direction: i. a heavy chain variable region ( VH ) of an anti-NKG2D antibody comprising an HCDR1 comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 1 to 10, an HCDR2 comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 14 to 23 and an HCDR3 comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 27 to 36; ii. a heavy chain constant region comprising a CH3 domain comprising one or more amino acid substitutions suitable for knobs-in-holes (KIH) dimerization with the CH3 domain of the third polypeptide chain; iii. optionally a linker; iv. an IL-15 receptor alpha (CD215) or a functional fragment thereof; v. optionally a linker; and vi. an IL-15 cytokine; and b) a second polypeptide chain comprising, in an N- to C-terminal direction: i. a light chain variable region (VL) of an anti-NKG2D antibody comprising an LCDR1 comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 40 to 49, an LCDR2 comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 53 to 62 and an LCDR3 comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 66 to 75; and ii. a light chain constant region; and c) a third polypeptide chain comprising, in an N- to C-terminal direction i. a heavy chain variable region (VH) of an anti-TAA antibody; ii. a human heavy chain constant region comprising a CH3 domain comprising one or more amino acid substitutions suitable for knobs-in-holes (KIH) dimerization with the CH3 domain of the first polypeptide chain; iii. optionally a linker; iv. an IL-15 receptor alpha (CD215) or a functional fragment thereof; v. optionally a linker; and vi. an IL-15 cytokine; and d) a fourth polypeptide chain comprising, in an N- to C-terminal direction: i. a light chain variable region (VL) of an anti-TAA antibody; and ii. a human light constant region.

[0390] Statement 3. The immunoconjugate may comprise: a) a first polypeptide chain comprising, in an N- to C- terminal direction: i. a heavy chain variable region ( VH ) of an anti-NKG2D antibody comprising an HCDR1 comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 1 to 10, an HCDR2 comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 14 to 23 and an HCDR3 comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 27 to 36; ii. a heavy chain constant region comprising a CH3 domain comprising or consisting of the sequence of SEQ ID NO: 270; iii. optionally a linker; iv. an I L-15 receptor alpha (CD215) or a functional fragment thereof; v. optionally a linker; and vi. an I L-15 cytokine; and b) a second polypeptide chain comprising, in an N- to C-terminal direction: i. a light chain variable region (VL) of an anti-NKG2D antibody comprising an LCDR1 comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 40 to 49, an LCDR2 comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 53 to 62 and an LCDR3 comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 66 to 75; and ii. a light chain constant region; and c) a third polypeptide chain comprising, in an N- to C-terminal direction i. a heavy chain variable region (VH) of an anti-TAA antibody; ii. a human heavy chain constant region comprising a CH3 domain comprising or consisting of the sequence of SEQ ID NO: 271; iii. optionally a linker; iv. an IL-15 receptor alpha (CD215) or a functional fragment thereof; v. optionally a linker; and vi. an IL-15 cytokine; and d) a fourth polypeptide chain comprising, in an N- to C-terminal direction: i. a light chain variable region (VL) of an anti-TAA antibody; and ii. a human light constant region.

[0391] Statement 14. The immunoconjugate may comprise: a) a first polypeptide chain comprising, in an N- to C- terminal direction: i. a heavy chain variable region (VH) of an anti-NKG2D antibody comprising an HCDR1 comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 1 to 10, an HCDR2 comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 14 to 23 and an HCDR3 comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 27 to 36; ii. a heavy chain constant region comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 105, 106, 203 and 314 to 325; i. optionally a linker; ii. an IL-15 receptor alpha (CD215) or a functional fragment thereof; iii. optionally a linker; and iv. an IL-15 cytokine; and b) a second polypeptide chain comprising, in an N- to C-terminal direction: i. a light chain variable region (VL) of an anti-NKG2D antibody comprising an LCDR1 comprising or consisting of a sequence selected from the group consisting of SEQ I D NOs: 40 to 49, an LCDR2 comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 53 to 62 and an LCDR3 comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 66 to 75; and ii. a light chain constant region comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 107, 108, 299, 310 and 326; and c) a third polypeptide chain comprising, in an N- to C-terminal direction i. a heavy chain variable region (VH) of an anti-TAA antibody; ii. a human heavy chain constant region comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 105, 106, 203 and 314 to 325; iii. optionally a linker; iv. an IL-15 receptor alpha (CD215) or a functional fragment thereof; v. optionally a linker; and vi. an IL-15 cytokine; and d) a fourth polypeptide chain comprising, in an N- to C-terminal direction: i. a light chain variable region (VL) of an anti-TAA antibody; and ii. a human light constant region comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 107, 108, 299, 310 and 326.

[0392] Statement 15. The immunoconjugate may comprise: a) a first polypeptide chain comprising, in an N- to C- terminal direction: i. a heavy chain variable region ( VH ) of an anti-NKG2D antibody comprising an HCDR1 comprising or consisting of the sequence of SEQ ID NO: 6, an HCDR2 comprising or consisting of the sequence of SEQ ID NO: 19 and an HCDR3 comprising or consisting of the sequence of SEQ ID NO: 32, optionally wherein the VH region comprises or consists of the sequence of SEQ ID NO:84; ii. a heavy chain constant region; iii. optionally a linker; iv. an IL-15 receptor alpha (CD215) or a functional fragment thereof comprising the sequence of SEQ ID NO: 263; v. optionally a linker; and vi. an IL-15 cytokine comprising or consisting of the sequence of SEQ ID NO: 151; and b) a second polypeptide chain comprising, in an N- to C-terminal direction: i. a light chain variable region (VL) of an anti-NKG2D antibody comprising an LCDR1 comprising or consisting of the sequence of SEQ ID NO: 45, an LCDR2 comprising or consisting of the sequence of SEQ ID NO: 58 and an LCDR3 comprising or consisting of the sequence of SEQ ID NO: 71, optionally wherein the VL region comprises or consists of the sequence of SEQ ID NO: 97; and ii. a light chain constant region; and c) a third polypeptide chain comprising, in an N- to C-terminal direction i. a heavy chain variable region (VH) of an anti-TAA antibody; ii. a human heavy chain constant region; iii. optionally a linker; iv. an IL-15 receptor alpha (CD215) or a functional fragment thereof comprising the sequence of SEQ ID NO: 263; v. optionally a linker; and vi. an IL-15 cytokine comprising or consisting of the sequence of SEQ ID NO: 151; and d) a fourth polypeptide chain comprising, in an N- to C-terminal direction: i. a light chain variable region (VL) of an anti-TAA antibody; and ii. a human light constant region.

[0393] Statement 16. The immunoconjugate may comprise: a) a first polypeptide chain comprising, in an N- to C- terminal direction: i. a heavy chain variable region ( VH ) of an anti-NKG2D antibody comprising an HCDR1 comprising or consisting of the sequence of SEQ ID NO: 6, an HCDR2 comprising or consisting of the sequence of SEQ ID NO: 19 and an HCDR3 comprising or consisting of the sequence of SEQ ID NO: 32, optionally wherein the VH region comprises or consists of the sequence of SEQ ID NO:84; ii. a heavy chain constant region comprising a CH3 domain comprising one or more amino acid substitutions suitable for knobs-in-holes (KIH) dimerization with the CH3 domain of the third polypeptide chain; iii. optionally a linker; iv. an IL-15 receptor alpha (CD215) or a functional fragment thereof; v. optionally a linker; and vi. an IL-15 cytokine; and b) a second polypeptide chain comprising, in an N- to C-terminal direction: i. a light chain variable region (VL) of an anti-NKG2D antibody comprising an LCDR1 comprising or consisting of the sequence of SEQ ID NO: 45, an LCDR2 comprising or consisting of the sequence of SEQ ID NO: 58 and an LCDR3 comprising or consisting of the sequence of SEQ ID NO: 71, optionally wherein the VL region comprises or consists of the sequence of SEQ ID NO: 97; and ii. a light chain constant region; and c) a third polypeptide chain comprising, in an N- to C-terminal direction i. a heavy chain variable region (VH) of an anti-TAA antibody; ii. a human heavy chain constant region comprising a CH3 domain comprising one or more amino acid substitutions suitable for knobs-in-holes (KIH) dimerization with the CH3 domain of the first polypeptide chain; iii. optionally a linker; iv. an IL-15 receptor alpha (CD215) or a functional fragment thereof; v. optionally a linker; and vi. an IL-15 cytokine; and d) a fourth polypeptide chain comprising, in an N- to C-terminal direction: i. a light chain variable region (VL) of an anti-TAA antibody; and ii. a human light constant region.

[0394] Statement 17. The immunoconjugate may comprise: a) a first polypeptide chain comprising, in an N- to C- terminal direction: i. a heavy chain variable region ( VH ) of an anti-NKG2D antibody comprising an HCDR1 comprising or consisting of the sequence of SEQ ID NO: 6, an HCDR2 comprising or consisting of the sequence of SEQ ID NO: 19 and an HCDR3 comprising or consisting of the sequence of SEQ ID NO: 32, optionally wherein the VH region comprises or consists of the sequence of SEQ ID NO:84; ii. a heavy chain constant region comprising a CH3 domain comprising or consisting of the sequence of SEQ ID NO: 270; iii. optionally a linker; iv. an IL-15 receptor alpha (CD215) or a functional fragment thereof; v. optionally a linker; and vi. an IL-15 cytokine; and b) a second polypeptide chain comprising, in an N- to C-terminal direction: i. a light chain variable region (VL) of an anti-NKG2D antibody comprising an LCDR1 comprising or consisting of the sequence of SEQ ID NO: 45, an LCDR2 comprising or consisting of the sequence of SEQ ID NO: 58 and an LCDR3 comprising or consisting of the sequence of SEQ ID NO: 71, optionally wherein the VL region comprises or consists of the sequence of SEQ ID NO: 97; and ii. a light chain constant region; and c) a third polypeptide chain comprising, in an N- to C-terminal direction i. a heavy chain variable region (VH) of an anti-TAA antibody; ii. a human heavy chain constant region comprising a CH3 domain comprising or consisting of the sequence of SEQ ID NO: 271; iii. optionally a linker; iv. an IL-15 receptor alpha (CD215) or a functional fragment thereof; v. optionally a linker; and vi. an IL-15 cytokine; and d) a fourth polypeptide chain comprising, in an N- to C-terminal direction: i. a light chain variable region (VL) of an anti-TAA antibody; and ii. a human light constant region.

[0395] Statement 18. The immunoconjugate may comprise:

[0396] 1) a first polypeptide chain comprising, in an N- to C- terminal direction: i. a heavy chain variable region ( VH ) of an anti-NKG2D antibody comprising an HCDR1 comprising or consisting of the sequence of SEQ ID NO: 6, an HCDR2 comprising or consisting of the sequence of SEQ ID NO: 19 and an HCDR3 comprising or consisting of the sequence of SEQ ID NO: 32, optionally wherein the VH region comprises or consists of the sequence of SEQ ID NO:84; ii. a heavy chain constant region comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 105, 106, 203 and 314 to 325; iii. optionally a linker; iv. an IL-15 receptor alpha (CD215) or a functional fragment thereof; v. optionally a linker; and vi. an IL-15 cytokine; and

[0397] 2) a second polypeptide chain comprising, in an N- to C-terminal direction: a) a light chain variable region (VL) of an anti-NKG2D antibody comprising an LCDR1 comprising or consisting of the sequence of SEQ ID NO: 45, an LCDR2 comprising or consisting of the sequence of SEQ ID NO: 58 and an LCDR3 comprising or consisting of the sequence of SEQ ID NO: 71, optionally wherein the VL region comprises or consists of the sequence of SEQ ID NO: 97; and b) a light chain constant region comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 107, 108, 299, 310 and 326; and

[0398] 3) a third polypeptide chain comprising, in an N- to C-terminal direction a) a heavy chain variable region (VH) of an anti-TAA antibody; b) a human heavy chain constant region comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 105, 106, 203 and 314 to 325; c) optionally a linker; d) an IL-15 receptor alpha (CD215) or a functional fragment thereof; e) optionally a linker; and f) an IL-15 cytokine; and

[0399] 4) a fourth polypeptide chain comprising, in an N- to C-terminal direction: a) a light chain variable region (VL) of an anti-TAA antibody; and b) a human light constant region comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 107, 108, 299, 310 and 326.

[0400] Statement 19. The immunoconjugate may comprise: a) a first polypeptide chain comprising, in an N- to C- terminal direction: i. a heavy chain variable region ( VH ) of an anti-NKG2D antibody comprising an HCDR1 comprising or consisting of the sequence of SEQ ID NO: 6, an HCDR2 comprising or consisting of the sequence of SEQ ID NO: 19 and an HCDR3 comprising or consisting of the sequence of SEQ ID NO: 32, optionally wherein the VH region comprises or consists of the sequence of SEQ ID NO:84; ii. a human heavy chain constant region comprising a CH3 domain comprising or consisting of the sequence of SEQ ID NO: 270; iii. optionally a linker comprising or consisting of the sequence of SEQ ID NO: 182; iv. an IL-15 receptor alpha (CD215) sushi domain comprising the sequence of SEQ ID NO: 263; v. a linker comprising or consisting of the sequence of SEQ ID NO: 265; and vi. an IL-15 cytokine comprising or consisting of SEQ ID NO: 151; and b) a second polypeptide chain comprising, in an N- to C-terminal direction: i. a light chain variable region (VL) of an anti-NKG2D antibody comprising an LCDR1 comprising or consisting of the sequence of SEQ ID NO: 45, an LCDR2 comprising or consisting of the sequence of SEQ ID NO: 58 and an LCDR3 comprising or consisting of the sequence of SEQ ID NO: 71, optionally wherein the VL region comprises or consists of the sequence of SEQ ID NO: 97; and ii. a human IgGl light constant region; and c) a third polypeptide chain comprising, in an N- to C-terminal direction i. a heavy chain variable region (VH) of an anti-TAA antibody; ii. a human heavy chain constant region comprising a CH3 domain comprising or consisting of SEQ ID NO: 271; iii. optionally a linker comprising or consisting of the sequence of SEQ ID NO: 182; iv. an IL-15 receptor alpha (CD215) sushi domain comprising the sequence of SEQ ID NO: 263; v. optionally a linker comprising or consisting of the sequence of SEQ ID NO: 265; and vi. an IL-15 cytokine comprising or consisting of SEQ ID NO: 151; and d) a fourth polypeptide chain comprising, in an N- to C-terminal direction: i. a light chain variable region (VL) of an anti-TAA antibody; and ii. a human IgGl light constant region.

[0401] Statement 20. The immunoconjugate may comprise: a) a first polypeptide chain comprising, in an N- to C- terminal direction: i. a heavy chain variable region ( VH ) of an anti-NKG2D antibody comprising an HCDR1 comprising or consisting of the sequence of SEQ ID NO: 6, an HCDR2 comprising or consisting of the sequence of SEQ ID NO: 19 and an HCDR3 comprising or consisting of the sequence of SEQ ID NO: 32, optionally wherein the VH region comprises or consists of the sequence of SEQ ID NO:84; ii. a human heavy chain constant region comprising or consisting of the sequence of SEQ ID NO: 314 or SEQ ID NO: 320; iii. optionally a linker comprising or consisting of the sequence of SEQ ID NO: 182; iv. an IL-15 receptor alpha (CD215) sushi domain comprising the sequence of SEQ ID NO: 263; v. a linker comprising or consisting of the sequence of SEQ ID NO: 265; and vi. an IL-15 cytokine comprising or consisting of SEQ ID NO: 151; and b) a second polypeptide chain comprising, in an N- to C-terminal direction: i. a light chain variable region (VL) of an anti-NKG2D antibody comprising an LCDR1 comprising or consisting of the sequence of SEQ ID NO: 45, an LCDR2 comprising or consisting of the sequence of SEQ ID NO: 58 and an LCDR3 comprising or consisting of the sequence of SEQ ID NO: 71, optionally wherein the VL region comprises or consists of the sequence of SEQ ID NO: 97; and ii. a light constant region comprising or consisting of the sequence of SEQ ID NO: 310; and c) a third polypeptide chain comprising, in an N- to C-terminal direction i. a heavy chain variable region (VH) of an anti-TAA antibody; ii. a human heavy chain constant region comprising or consisting of the sequence of SEQ ID NO: 315 or SEQ ID NO: 321; iii. optionally a linker comprising or consisting of the sequence of SEQ ID NO: 182; iv. an IL-15 receptor alpha (CD215) sushi domain comprising the sequence of SEQ ID NO: 263; v. optionally a linker comprising or consisting of the sequence of SEQ ID NO: 265; and vi. an IL-15 cytokine comprising or consisting of SEQ ID NO: 151; and d) a fourth polypeptide chain comprising, in an N- to C-terminal direction: i. a light chain variable region (VL) of an anti-TAA antibody; and ii. a light constant region comprising or consisting of the sequence of SEQ ID NO: 310.

[0402] Statement 21. The immunoconjugate may comprise: a) a first polypeptide chain comprising, in an N- to C- terminal direction: i. a heavy chain variable region ( VH ) of an anti-NKG2D antibody comprising an HCDR1 comprising or consisting of the sequence of SEQ ID NO: 6, an HCDR2 comprising or consisting of the sequence of SEQ ID NO: 19 and an HCDR3 comprising or consisting of the sequence of SEQ ID NO: 32, optionally wherein the VH region comprises or consists of the sequence of SEQ ID NO:84; ii. a human heavy chain constant region comprising or consisting of the sequence of SEQ ID NO: 316 or SEQ ID NO: 322; iii. optionally a linker comprising or consisting of the sequence of SEQ ID NO: 182; iv. an IL-15 receptor alpha (CD215) sushi domain comprising the sequence of SEQ ID NO: 263; v. a linker comprising or consisting of the sequence of SEQ ID NO: 265; and vi. an IL-15 cytokine comprising or consisting of SEQ ID NO: 151; and b) a second polypeptide chain comprising, in an N- to C-terminal direction: i. a light chain variable region (VL) of an anti-NKG2D antibody comprising an LCDR1 comprising or consisting of the sequence of SEQ ID NO: 45, an LCDR2 comprising or consisting of the sequence of SEQ ID NO: 58 and an LCDR3 comprising or consisting of the sequence of SEQ ID NO: 71, optionally wherein the VL region comprises or consists of the sequence of SEQ ID NO: 97; and ii. a light constant region comprising or consisting of the sequence of SEQ ID NO: 299; and c) a third polypeptide chain comprising, in an N- to C-terminal direction i. a heavy chain variable region (VH) of an anti-TAA antibody; ii. a human heavy chain constant region comprising or consisting of the sequence of SEQ ID NO: 317 or SEQ ID NO: 323; iii. optionally a linker comprising or consisting of the sequence of SEQ ID NO: 182; iv. an IL-15 receptor alpha (CD215) sushi domain comprising the sequence of SEQ ID NO: 263; v. optionally a linker comprising or consisting of the sequence of SEQ ID NO: 265; and vi. an IL-15 cytokine comprising or consisting of SEQ ID NO: 151; and d) a fourth polypeptide chain comprising, in an N- to C-terminal direction: i. a light chain variable region (VL) of an anti-TAA antibody; and ii. a light constant region comprising or consisting of the sequence of SEQ ID NO: 299.

[0403] Statement 22. The immunoconjugate may comprise: a) a first polypeptide chain comprising, in an N- to C- terminal direction: i. a heavy chain variable region ( VH ) of an anti-NKG2D antibody comprising an HCDR1 comprising or consisting of the sequence of SEQ ID NO: 6, an HCDR2 comprising or consisting of the sequence of SEQ ID NO: 19 and an HCDR3 comprising or consisting of the sequence of SEQ ID NO: 32, optionally wherein the VH region comprises or consists of the sequence of SEQ ID NO:84; ii. a human heavy chain constant region comprising or consisting of the sequence of SEQ ID NO: 318 or SEQ ID NO: 324; iii. optionally a linker comprising or consisting of the sequence of SEQ ID NO: 182; iv. an IL-15 receptor alpha (CD215) sushi domain comprising the sequence of SEQ ID NO: 263; v. a linker comprising or consisting of the sequence of SEQ ID NO: 265; and vi. an IL-15 cytokine comprising or consisting of SEQ ID NO: 151; and b) a second polypeptide chain comprising, in an N- to C-terminal direction: i. a light chain variable region (VL) of an anti-NKG2D antibody comprising an LCDR1 comprising or consisting of the sequence of SEQ ID NO: 45, an LCDR2 comprising or consisting of the sequence of SEQ ID NO: 58 and an LCDR3 comprising or consisting of the sequence of SEQ ID NO: 71, optionally wherein the VL region comprises or consists of the sequence of SEQ ID NO: 97; and ii. a light constant region comprising or consisting of the sequence of SEQ ID NO: 326; and c) a third polypeptide chain comprising, in an N- to C-terminal direction i. a heavy chain variable region (VH) of an anti-TAA antibody; ii. a human heavy chain constant region comprising or consisting of the sequence of SEQ ID NO: 319 or SEQ ID NO: 325; iii. optionally a linker comprising or consisting of the sequence of SEQ ID NO: 182; iv. an IL-15 receptor alpha (CD215) sushi domain comprising the sequence of SEQ ID NO: 263; v. optionally a linker comprising or consisting of the sequence of SEQ ID NO: 265; and vi. an IL-15 cytokine comprising or consisting of SEQ ID NO: 151; and d) a fourth polypeptide chain comprising, in an N- to C-terminal direction: i. a light chain variable region (VL) of an anti-TAA antibody; and ii. a light constant region comprising or consisting of the sequence of SEQ ID NO: 326.

[0404] Statement 23. The immunoconjugate may comprise: a) a first polypeptide chain comprising the heavy chain sequence of SEQ ID NO: 290 b) a second polypeptide chain comprising the light chain sequence of SEQ ID NO: 140; and c) a third polypeptide chain comprising, in an N- to C-terminal direction i. a heavy chain variable region (VH) of an anti-TAA antibody; ii. a human heavy chain constant region; iii. optionally a linker; iv. an IL-15 receptor alpha (CD215) sushi domain; v. optionally a linker; and vi. an IL-15 cytokine; and e) a fourth polypeptide chain comprising, in an N- to C-terminal direction: i. a light chain variable region (VL) of an anti-TAA antibody; and ii. a light constant region.

[0405] Statement 23a. The immunoconjugate may comprise: a) a first polypeptide chain comprising the heavy chain sequence of SEQ ID NO: 290 b) a second polypeptide chain comprising the light chain sequence of SEQ ID NO: 140; and c) a third polypeptide chain comprising, in an N- to C-terminal direction vii. a heavy chain variable region (VH) of an anti-HER2 antibody, optionally comprising or consisting of the sequence of SEQ ID NO: 304; viii. a human heavy chain constant region; ix. optionally a linker; x. an IL-15 receptor alpha (CD215) sushi domain; xi. optionally a linker; and xii. an IL-15 cytokine; and f) a fourth polypeptide chain comprising, in an N- to C-terminal direction: i. a light chain variable region (VL) of an anti-TAA antibody optionally comprising or consisting of the sequence of SEQ ID NO: 305; and ii. a light constant region.

[0406] Statement 24. The immunoconjugate may comprise: a) a first polypeptide chain comprising the heavy chain sequence of SEQ ID NO: 290 b) a second polypeptide chain comprising the light chain sequence of SEQ ID NO: 140; and c) a third polypeptide chain comprising, in an N- to C-terminal direction i) a heavy chain variable region (VH) of an anti-TAA antibody; ii) a human heavy chain constant region comprising a CH3 domain comprising the sequence of SEQ ID NO: 271; ill) optionally a linker comprising or consisting of the sequence of SEQ ID NO: 182; iv) an IL-15 receptor alpha (CD215) sushi domain comprising the sequence of SEQ ID NO: 263; v) optionally a linker comprising or consisting of the sequence of SEQ ID NO: 265; and vi) an IL-15 cytokine comprising or consisting of SEQ ID NO: 151; and g) a fourth polypeptide chain comprising, in an N- to C-terminal direction: i. a light chain variable region (VL) of an anti-TAA antibody; and ii. a light constant region.

[0407] Statement 24a. The immunoconjugate may comprise: a) a first polypeptide chain comprising the heavy chain sequence of SEQ ID NO: 290 b) a second polypeptide chain comprising the light chain sequence of SEQ ID NO: 140; and c) a third polypeptide chain comprising, in an N- to C-terminal direction vii) a heavy chain variable region (VH) of an anti-HER2 antibody optionally comprising or consisting of the sequence of SEQ ID NO: 304; viii) a human heavy chain constant region comprising a CH3 domain comprising the sequence of SEQ ID NO: 271; ix) optionally a linker comprising or consisting of the sequence of SEQ ID NO: 182; x) an IL-15 receptor alpha (CD215) sushi domain comprising the sequence of SEQ ID NO: 263; xi) optionally a linker comprising or consisting of the sequence of SEQ ID NO: 265; and xii) an IL-15 cytokine comprising or consisting of SEQ ID NO: 151; and h) a fourth polypeptide chain comprising, in an N- to C-terminal direction: i. a light chain variable region (VL) of an anti-HER2 antibody optionally comprising or consisting of the sequence of SEQ ID NO: 305; and ii. a light constant region.

[0408] Statement 24b. The immunoconjugate may comprise: d) a first polypeptide chain comprising the heavy chain sequence of SEQ ID NO: 290 e) a second polypeptide chain comprising the light chain sequence of SEQ ID NO: 140; and f) a third polypeptide chain comprising the heavy chain sequence of SEQ ID NO: 308; and g) a fourth polypeptide chain comprising the light chain sequence of SEQ ID NO 306:

[0409] Statement 24c. The immunoconjugate may comprise: a) a first polypeptide chain comprising the heavy chain sequence of SEQ ID NO: 290 b) a second polypeptide chain comprising the light chain sequence of SEQ ID NO: 140; and c) a third polypeptide chain comprising the heavy chain sequence of SEQ ID NO: 307; and d) a fourth polypeptide chain comprising the light chain sequence of SEQ ID NO 306:

[0410] Statement 25. The immunoconjugate may comprise: a) a first polypeptide chain comprising the heavy chain sequence of SEQ ID NO: 292 b) a second polypeptide chain comprising the light chain sequence of SEQ ID NO: 294; and c) a third polypeptide chain comprising, in an N- to C-terminal direction iii. a heavy chain variable region ( VH ) of an anti-TAA antibody; iv. a human heavy chain constant region; v. optionally a linker; vi. an IL-15 receptor alpha (CD215) sushi domain; vii. optionally a linker; and viii. an IL-15 cytokine; and d) a fourth polypeptide chain comprising, in an N- to C-terminal direction: i. a light chain variable region (VL) of an anti-TAA antibody; and ii. a light constant region. Statement 25a. The immunoconjugate may comprise: a) a first polypeptide chain comprising the heavy chain sequence of SEQ ID NO: 292 b) a second polypeptide chain comprising the light chain sequence of SEQ ID NO: 294; and c) a third polypeptide chain comprising, in an N- to C-terminal direction ix. a heavy chain variable region (VH) of an anti-HER2 antibody optionally comprising or consisting of the sequence of SEQ ID NO: 304; x. a human heavy chain constant region; xi. optionally a linker; xii. an IL-15 receptor alpha (CD215) sushi domain; xiii. optionally a linker; and xiv. an IL-15 cytokine; and d) a fourth polypeptide chain comprising, in an N- to C-terminal direction: i. a light chain variable region (VL) of an anti-HER2 antibody optionally comprising or consisting of the sequence of SEQ ID NO: 305; and ii. a light constant region.

[0411] Statement 26. The immunoconjugate may comprise: a) a first polypeptide chain comprising the heavy chain sequence of SEQ ID NO: 292 b) a second polypeptide chain comprising the light chain sequence of SEQ ID NO: 294; and c) a third polypeptide chain comprising, in an N- to C-terminal direction i. a heavy chain variable region ( VH ) of an anti-TAA antibody; ii. a human heavy chain constant region comprising a CH3 domain comprising the sequence of SEQ ID NO: 271; iii. optionally a linker comprising or consisting of the sequence of SEQ ID NO: 182; iv. an IL-15 receptor alpha (CD215) sushi domain comprising the sequence of SEQ ID NO: 263; v. optionally a linker comprising or consisting of the sequence of SEQ ID NO: 265; and vi. an IL-15 cytokine comprising or consisting of SEQ ID NO: 151; and d) a fourth polypeptide chain comprising, in an N- to C-terminal direction: i. a light chain variable region (VL) of an anti-TAA antibody; and ii. a light constant region.

[0412] Statement 26a. The immunoconjugate may comprise: a) a first polypeptide chain comprising the heavy chain sequence of SEQ ID NO: 292 b) a second polypeptide chain comprising the light chain sequence of SEQ ID NO: 294; and c) a third polypeptide chain comprising, in an N- to C-terminal direction i. a heavy chain variable region ( VH ) of an anti-HER2 antibody optionally comprising or consisting of the sequence of SEQ ID NO: 304; ii. a human heavy chain constant region comprising a CH3 domain comprising the sequence of SEQ ID NO: 271; iii. optionally a linker comprising or consisting of the sequence of SEQ ID NO: 182; iv. an IL-15 receptor alpha (CD215) sushi domain comprising the sequence of SEQ ID NO: 263; v. optionally a linker comprising or consisting of the sequence of SEQ ID NO: 265; and vi. an IL-15 cytokine comprising or consisting of SEQ ID NO: 151; and d) a fourth polypeptide chain comprising, in an N- to C-terminal direction: i. a light chain variable region (VL) of an anti-HER2 antibody optionally comprising or consisting of the sequence of SEQ ID NO: 305; and ii. a light constant region.

[0413] Statement 26b. The immunoconjugate may comprise: a) a first polypeptide chain comprising the heavy chain sequence of SEQ ID NO: 292 b) a second polypeptide chain comprising the light chain sequence of SEQ ID NO: 294; and e) a third polypeptide chain comprising the heavy chain sequence of SEQ ID NO: 308; and f) a fourth polypeptide chain comprising the light chain sequence of SEQ ID NO 306.

[0414] Statement 26c. The immunoconjugate may comprise: a) a first polypeptide chain comprising the heavy chain sequence of SEQ ID NO: 292 b) a second polypeptide chain comprising the light chain sequence of SEQ ID NO: 294; and g) a third polypeptide chain comprising the heavy chain sequence of SEQ ID NO: 307; and h) a fourth polypeptide chain comprising the light chain sequence of SEQ ID NO 306.

[0415] Statement 27. The immunoconjugate may comprise: a) a first polypeptide chain comprising the heavy chain sequence of SEQ ID NO: 295 b) a second polypeptide chain comprising the light chain sequence of SEQ ID NO: 297; and c) a third polypeptide chain comprising, in an N- to C-terminal direction i. a heavy chain variable region (VH) of an anti-TAA antibody; ii. a human heavy chain constant region; iii. optionally a linker; iv. an IL-15 receptor alpha (CD215) sushi domain; v. optionally a linker; and vi. an IL-15 cytokine; and d) a fourth polypeptide chain comprising, in an N- to C-terminal direction: i. a light chain variable region (VL) of an anti-TAA antibody; and ii. a light constant region.

[0416] Statement 27a. The immunoconjugate may comprise: a) a first polypeptide chain comprising the heavy chain sequence of SEQ ID NO: 295 b) a second polypeptide chain comprising the light chain sequence of SEQ ID NO: 297; and c) a third polypeptide chain comprising, in an N- to C-terminal direction i. a heavy chain variable region (VH) of an anti-HER2 antibody optionally comprising or consisting of the sequence of SEQ ID NO: 304; ii. a human heavy chain constant region; iii. optionally a linker; iv. an IL-15 receptor alpha (CD215) sushi domain; v. optionally a linker; and vi. an IL-15 cytokine; and d) a fourth polypeptide chain comprising, in an N- to C-terminal direction: i. a light chain variable region (VL) of an anti-HER2 antibody optionally comprising or consisting of the sequence of SEQ ID NO: 304; and ii. a light constant region.

[0417] Statement 28. The immunoconjugate may comprise: a) a first polypeptide chain comprising the heavy chain sequence of SEQ ID NO: 295 b) a second polypeptide chain comprising the light chain sequence of SEQ ID NO: 297; and c) a third polypeptide chain comprising, in an N- to C-terminal direction i. a heavy chain variable region ( VH ) of an anti-TAA antibody; ii. a human heavy chain constant region comprising a CH3 domain comprising the sequence of SEQ ID NO: 271; iii. optionally a linker comprising or consisting of the sequence of SEQ ID NO: 182; iv. an IL-15 receptor alpha (CD215) sushi domain comprising the sequence of SEQ ID NO: 263; v. optionally a linker comprising or consisting of the sequence of SEQ ID NO: 265; and vi. an IL-15 cytokine comprising or consisting of SEQ ID NO: 151; and d) a fourth polypeptide chain comprising, in an N- to C-terminal direction: i. a light chain variable region (VL) of an anti-TAA antibody; and ii. a light constant region.

[0418] Statement 28a. The immunoconjugate may comprise: a) a first polypeptide chain comprising the heavy chain sequence of SEQ ID NO: 295 b) a second polypeptide chain comprising the light chain sequence of SEQ ID NO: 297; and c) a third polypeptide chain comprising, in an N- to C-terminal direction i. a heavy chain variable region ( VH ) of an anti-HER2 antibody optionally comprising or consisting of the sequence of SEQ ID NO: 304; ii. a human heavy chain constant region comprising a CH3 domain comprising the sequence of SEQ ID NO: 271; iii. optionally a linker comprising or consisting of the sequence of SEQ ID NO: 182; iv. an IL-15 receptor alpha (CD215) sushi domain comprising the sequence of SEQ ID NO: 263; v. optionally a linker comprising or consisting of the sequence of SEQ ID NO: 265; and vi. an IL-15 cytokine comprising or consisting of SEQ ID NO: 151; and d) a fourth polypeptide chain comprising, in an N- to C-terminal direction: i. a light chain variable region (VL) of an anti-HER2 antibody optionally comprising or consisting of the sequence of SEQ ID NO: 304; and ii. a light constant region.

[0419] Statement 28b. The immunoconjugate may comprise: a) a first polypeptide chain comprising the heavy chain sequence of SEQ ID NO: 295 b) a second polypeptide chain comprising the light chain sequence of SEQ ID NO: 297; and c) a third polypeptide chain comprising the heavy chain sequence of SEQ ID NO: 308; and d) a fourth polypeptide chain comprising the light chain sequence of SEQ ID NO 306.

[0420] Statement 28c. The immunoconjugate may comprise: a) a first polypeptide chain comprising the heavy chain sequence of SEQ ID NO: 295 b) a second polypeptide chain comprising the light chain sequence of SEQ ID NO: 297; and c) a third polypeptide chain comprising the heavy chain sequence of SEQ ID NO: 307; and d) a fourth polypeptide chain comprising the light chain sequence of SEQ ID NO 306.

[0421] Statement 29. The immunoconjugate may comprise: a) a first polypeptide chain comprising or consisting of a sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 95%, at least 97%, at least 98% or at least 99% identity to a sequence selected from the group consisting of SEQ ID NOs: 156 to 165, SEQ ID NO: 188, 189, 191, 192, 195, 200, 290, 292 and 295; and b) a second polypeptide chain comprising or consisting of a sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 95%, at least 97%, at least 98% or at least 99% identity to a sequence selected from the group consisting of SEQ ID NOs: 135 to 144, 294 and 297; c) a third polypeptide chain comprising, in an N- to C-terminal direction i. a heavy chain variable region ( VH ) of an anti-TAA antibody; ii. a human heavy chain constant region; iii. optionally a linker; iv. an IL-15 receptor alpha (CD215) sushi domain; v. optionally a linker; and vi. an IL-15 cytokine; and e) a fourth polypeptide chain comprising, in an N- to C-terminal direction: i. a light chain variable region (VL) of an anti-TAA antibody; and ii. a light constant region.

[0422] Statement 30. The immunoconjugate may comprise: a) a first polypeptide chain comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 156 to 165, SEQ ID NO: 188, 189, 191, 192, 195, 200, 290, 292 and 295; and b) a second polypeptide chain comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 135 to 144, 294 and 297; c) a third polypeptide chain comprising, in an N- to C-terminal direction i. a heavy chain variable region (VH) of an anti-TAA antibody; ii. a human heavy chain constant region; iii. optionally a linker; iv. an IL-15 receptor alpha (CD215) sushi domain; v. optionally a linker; and vi. an IL-15 cytokine; and d) a fourth polypeptide chain comprising, in an N- to C-terminal direction: i. a light chain variable region (VL) of an anti-TAA antibody; and ii. a light constant region.

[0423] Statement 30a. The immunoconjugate may comprise: a) a first polypeptide chain comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 156 to 165, SEQ ID NO: 188, 189, 191, 192, 195, 200, 290, 292 and 295; and b) a second polypeptide chain comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 135 to 144, 294 and 297; c) a third polypeptide chain comprising or consisting of SEQ ID NO: 307 or 308; and d) a fourth polypeptide chain comprising or conspiring of SEQ ID NO: 306.

[0424] Statement 40. The immunoconjugates may comprise:

[0425]

[0426] Table 10

[0427]

[0428] NKp30 - 2+1+1 (4 chain)

[0429] Any of the specific NKG2D immunoconjugates as described above may have the anti-NKG2D binding domain replaced with an anti-NKp30 binding domain as described herein (for example Hll / Lll or H12 / L12).

[0430] Statement 41. The immunoconjugates may comprise:

[0431] Table 12

[0432] NKp46 - 2+1+1 (4 chain)

[0433] Any of the specific NKG2D immunoconjugates as described above may have the anti-NKG2D binding domain replaced with an anti-NKp46 binding domain as described herein (for example H13 / L13).

[0434] Statement 42. The immunoconjugates may comprise:

[0435] Table 13

[0436] Specific immunoconjugates - 1+1+1 (4 chain)

[0437] The immunoconjugates of the invention may be formatted in a "1+1+1" format as defined herein and shown in Figure 1(A). These immunoconjugates comprise: a. a multivalent antibody or antigen-binding fragment thereof comprising: i. two antibody binding domains wherein:

[0438] 1. the first antibody binding domain specifically binds to a first target antigen selected from the group consisting of NKG2D, NKp30, NKp46, NKp44 and DNAM-1; and

[0439] 2. the second antibody binding domain specifically binds to a second, different target antigen optionally a TAA such as HER2, EGFR, CD19 or CD20; ii. a human immunoglobulin Fc domain comprising:

[0440] 1. a first chain comprising in an N- to C- terminal direction a CH2 domain and a CH3 domain; and

[0441] 2. a second chain comprising in an N- to C- terminal direction a CH2 domain and a CH3 domain; and b. an IL-15 receptor alpha (CD215) or a functional fragment thereof covalently linked to the C-termini of the first or second chain of the Fc domain (optionally via a linker 1) and an human IL-15 cytokine covalently linked to the C-termini of the IL-15 receptor alpha (CD215) or functional fragment thereof (optionally via a linker 2).

[0442] The "1+1+1" immunoconjugates are the same as the "2+1+1" immunoconjugates, except there is only one IL- 15 receptor alpha (CD215) or a functional fragment thereof and only one IL-15 cytokine.

[0443] Each of the components of the 1+1+1 immunocytokine may be as described herein. Preferably the first antibody binding domain binds NKG2D and the second antigen binds a TAA. Preferably, the first antibody binding domain comprises sequences from the anti-NKG2D antibody described herein as H6 / L6 (21F2). Preferably, the CH3 domain of the first chain comprises or consists of the sequence of SEQ. ID NO: 270 (knob) and the CH3 domain of the second chain comprises or consists of the sequence of SEQ I D NO: 271 (hole). Preferably no linker 1 is present. If linker 1 is present, preferably it comprises or consists of the sequence of SEQ ID NO: 182. Preferably the IL-15 receptor alpha (CD215) or a functional fragment thereof is human I L-15 receptor alpha (CD215) sushi domains comprising the sequence of SEQ ID NO: 263, for example SEQ ID NO: 149. Preferably linker 2 comprises or consists of the sequence of SEQ ID NO: 265. Preferably the human IL-15 cytokine comprises or consists of the sequence of SEQ ID NO: 151.

[0444] As shown in Figure 1(C), in the immunoconjugate formats described herein:

[0445] • the immunoglobulin heavy chain of the first antibody binding domain of the multivalent antibody is referred to as the first polypeptide chain

[0446] • the immunoglobulin light chain of the first antibody binding domain of the multivalent antibody is referred to as the second polypeptide chain.

[0447] • the immunoglobulin heavy chain of the second antibody binding domain of the multivalent antibody is referred to as the third polypeptide chain

[0448] • the immunoglobulin light chain of the second antibody binding domain of the multivalent antibody is referred to as the fourth polypeptide chain

[0449] The first polypeptide (heavy chain) and second polypeptide (light chain) forms a first subunit. The third polypeptide (heavy chain) and fourth polypeptide (light chain) forms a second subunit. This then heterodimerizes to form the final immunoconjugate comprising two said subunits and thus a total of four polypeptide chains. Said heterodimerization may occur via one of the mechanisms for engineering heterodimerization described herein, preferably via a KiH method. The immunoconjugates can therefore be described as dimers, with one monomer subunit of the dimer comprising the first polypeptide chain and the second polypeptide chain and the second monomer subunit of the dimer comprising the third polypeptide chain and the fourth polypeptide chain. In these embodiments the immunoconjugate is considered heterodimeric. In some embodiments, the immunoconjugate may have been selectively purified in order to arrive at such a heterodimeric species and remove or reduce any unwanted fragments, higher order aggregates, and alternative homodimeric species that may be considered impurities. In some embodiments the heterodimeric immunoconjugate is the preferred species in a mixture that includes said impurities.

[0450] The anti-NKG2D antibody, anti-NKp30 antibody, anti-NKp46 antibody, anti-NKp44 antibody or anti-DNAM-1 antibody referred to in the immunoconjugate formats described below may be any of the antibodies Hl / Ll to H13 / L13, or could be another antibody against these targets known in the art. Statement 43. The immunoconjugate may comprise: a) a first polypeptide chain comprising, in an N- to C- terminal direction i) a heavy chain variable region (VH) of an anti-NKG2D antibody, an anti-NKp30 antibody, an anti- NKp46 antibody, an anti-NKp44 antibody or an anti-DNAM-1 antibody; ii) a human heavy chain constant region; ill) optionally a linker; iv) an IL-15 receptor alpha (CD215) or a functional fragment thereof; v) optionally a linker; and vi) an IL-15 cytokine; and b) a second polypeptide chain comprising, in an N- to C-terminal direction: i) a light chain variable region (VL) of an anti-NKG2D antibody, an anti-NKp30 antibody, an anti- NKp46 antibody, an anti-NKp44 antibody or an anti-DNAM-1 antibody; and ii) a human light constant region; and c) a third polypeptide chain comprising, in an N- to C-terminal direction i) a heavy chain variable region (VH) of an anti-TAA antibody; and ii) a human heavy chain constant region; d) a fourth polypeptide chain comprising, in an N- to C-terminal direction: i) a light chain variable region (VL) of an anti-TAA antibody; and ii) a human light constant region.

[0451] Statement 44. The immunoconjugate may comprise: a) a first polypeptide chain comprising, in an N- to C- terminal direction: i) a heavy chain variable region (VH) of an anti-NKG2D antibody, an anti-NKp30 antibody, an anti- NKp46 antibody, an anti-NKp44 antibody or an anti-DNAM-1 antibody; ii) a human heavy chain constant region comprising a CH3 domain comprising one or more amino acid substitutions suitable for knobs-in-holes (KIH) dimerization with the CH3 domain of the third polypeptide chain; ill) optionally a linker; iv) an IL-15 receptor alpha (CD215) or a functional fragment thereof; v) optionally a linker; and vi) an IL-15 cytokine; and b) a second polypeptide chain comprising, in an N- to C-terminal direction: i) a light chain variable region (VL) of an anti-NKG2D antibody, an anti-NKp30 antibody, an anti- NKp46 antibody, an anti-NKp44 antibody or an anti-DNAM-1 antibody; and ii) a human light constant region; and c) a third polypeptide chain comprising, in an N- to C-terminal direction i) a heavy chain variable region (VH) of an anti-TAA antibody; ii) a human heavy chain constant region comprising a CH3 domain comprising one or more amino acid substitutions suitable for knobs-in-holes (KIH) dimerization with the CH3 domain of the first polypeptide chain; d) a fourth polypeptide chain comprising, in an N- to C-terminal direction: i) a light chain variable region (VL) of an anti-TAA antibody; and ii) a human light constant region.

[0452] Statement 45. The immunoconjugate may comprise: a) a first polypeptide chain comprising, in an N- to C- terminal direction: i) a heavy chain variable region (VH) of an anti-NKG2D antibody; ii) a human heavy chain constant region comprising a CH3 domain comprising one or more amino acid substitutions suitable for knobs-in-holes (KIH) dimerization with the CH3 domain of the third polypeptide chain; ill) optionally a linker; iv) an IL-15 receptor alpha (CD215) or a functional fragment thereof; v) optionally a linker; and vi) an IL-15 cytokine; and b) a second polypeptide chain comprising, in an N- to C-terminal direction: i) a light chain variable region (VL) of an anti-NKG2D antibody; and ii) a human light constant region; and c) a third polypeptide chain comprising, in an N- to C-terminal direction i) a heavy chain variable region (VH) of an anti-TAA antibody; ii) a human heavy chain constant region comprising a CH3 domain comprising one or more amino acid substitutions suitable for knobs-in-holes (KIH) dimerization with the CH3 domain of the first polypeptide chain; d) a fourth polypeptide chain comprising, in an N- to C-terminal direction: i) a light chain variable region (VL) of an anti-TAA antibody; and ii) a human light constant region. Statement 46. The immunoconjugate may comprise: a) a first polypeptide chain comprising, in an N- to C- terminal direction: i) a heavy chain variable region (VH) of an anti-NKG2D antibody, an anti-NKp30 antibody, an anti- NKp46 antibody, an anti-NKp44 antibody or an anti-DNAM-1 antibody; ii) a human heavy chain constant region comprising a CH3 domain comprising or consisting of the sequence of SEQ ID NO: 270; ill) optionally a linker comprising or consisting of 5 amino acids or less; iv) an IL-15 receptor alpha (CD215) sushi domain comprising the sequence of SEQ ID NO: 263; v) a linker comprising or consisting of at least 30 amino acids; and vi) an IL-15 cytokine comprising or consisting of SEQ ID NO: 151; and b) a second polypeptide chain comprising, in an N- to C-terminal direction: i) a light chain variable region (VL) of an anti-NKG2D antibody, an anti-NKp30 antibody, an anti- NKp46 antibody, an anti-NKp44 antibody or an anti-DNAM-1 antibody; and ii) a human IgGl light constant region; and c) a third polypeptide chain comprising, in an N- to C-terminal direction i) a heavy chain variable region (VH) of an anti-TAA antibody; ii) a human heavy chain constant region comprising a CH3 domain comprising or consisting of SEQ ID NO: 271; d) a fourth polypeptide chain comprising, in an N- to C-terminal direction: i) a light chain variable region (VL) of an anti-TAA antibody; and ii) a human IgGl light constant region.

[0453] Statement 47. The immunoconjugate may comprise: a) a first polypeptide chain comprising, in an N- to C- terminal direction: i) a heavy chain variable region (VH) of an anti-NKG2D antibody, an anti-NKp30 antibody, an anti- NKp46 antibody, an anti-NKp44 antibody or an anti-DNAM-1 antibody; ii) a human heavy chain constant region comprising a CH3 domain comprising or consisting of the sequence of SEQ ID NO: 270; ill) optionally a linker comprising or consisting of the sequence of SEQ ID NO: 182; iv) an IL-15 receptor alpha (CD215) sushi domain comprising the sequence of SEQ ID NO: 263; v) a linker comprising or consisting of the sequence of SEQ ID NO: 265; and vi) an IL-15 cytokine comprising or consisting of SEQ ID NO: 151; and b) a second polypeptide chain comprising, in an N- to C-terminal direction: i) a light chain variable region (VL) of an anti-NKG2D antibody, an anti-NKp30 antibody, an anti-

[0454] NKp46 antibody, an anti-NKp44 antibody or an anti-DNAM-1 antibody; and ii) a human IgGl light constant region; and c) a third polypeptide chain comprising, in an N- to C-terminal direction i) a heavy chain variable region (VH) of an anti-TAA antibody; ii) a human heavy chain constant region comprising a CH3 domain comprising or consisting of SEQ ID NO: 271; d) a fourth polypeptide chain comprising, in an N- to C-terminal direction: i) a light chain variable region (VL) of an anti-TAA antibody; and ii) a human IgGl light constant region.

[0455] Statement 48. The immunoconjugate may comprise: a) a first polypeptide chain comprising, in an N- to C- terminal direction: i. a heavy chain variable region (VH) of an anti-NKG2D antibody, an anti-NKp30 antibody, an anti- NKp46 antibody, an anti-NKp44 antibody or an anti-DNAM-1 antibody; ii. a human heavy chain constant region comprising or consisting of the sequence of SEQ ID NO: 314 or SEQ ID NO: 320; ill. optionally a linker comprising or consisting of the sequence of SEQ ID NO: 182; iv. an IL-15 receptor alpha (CD215) sushi domain comprising the sequence of SEQ ID NO: 263; v. a linker comprising or consisting of the sequence of SEQ ID NO: 265; and vi. an IL- 15 cytokine comprising or consisting of SEQ ID NO: 151; and b) a second polypeptide chain comprising, in an N- to C-terminal direction: i) a light chain variable region (VL) of an anti-NKG2D antibody, an anti-NKp30 antibody, an anti- NKp46 antibody, an anti-NKp44 antibody or an anti-DNAM-1 antibody; and ii) a light constant region comprising or consisting of the sequence of SEQ ID NO: 310; and c) a third polypeptide chain comprising, in an N- to C-terminal direction i) a heavy chain variable region (VH) of an anti-TAA antibody; ii) a human heavy chain constant region comprising or consisting of the sequence of SEQ ID NO: 315 or SEQ ID NO: 321; d) a fourth polypeptide chain comprising, in an N- to C-terminal direction: i) a light chain variable region (VL) of an anti-TAA antibody; and ii) a light constant region comprising or consisting of the sequence of SEQ ID NO: 310. Statement 49. The immunoconjugate may comprise: a) a first polypeptide chain comprising, in an N- to C- terminal direction: i. a heavy chain variable region (VH) of an anti-NKG2D antibody, an anti-NKp30 antibody, an anti- NKp46 antibody, an anti-NKp44 antibody or an anti-DNAM-1 antibody; ii. a human heavy chain constant region comprising or consisting of the sequence of SEQ ID NO: 316 or SEQ ID NO: 322; ill. optionally a linker comprising or consisting of the sequence of SEQ ID NO: 182; iv. an IL-15 receptor alpha (CD215) sushi domain comprising the sequence of SEQ ID NO: 263; v. a linker comprising or consisting of the sequence of SEQ ID NO: 265; and vi. an IL- 15 cytokine comprising or consisting of SEQ ID NO: 151; and b) a second polypeptide chain comprising, in an N- to C-terminal direction: c) a light chain variable region (VL) of an anti-NKG2D antibody, an anti-NKp30 antibody, an anti- NKp46 antibody, an anti-NKp44 antibody or an anti-DNAM-1 antibody; and d) a light constant region comprising or consisting of the sequence of SEQ ID NO: 299; and e) a third polypeptide chain comprising, in an N- to C-terminal direction f) a heavy chain variable region (VH) of an anti-TAA antibody; g) a human heavy chain constant region comprising or consisting of the sequence of SEQ ID NO: 317 or SEQ ID NO: 323; h) a fourth polypeptide chain comprising, in an N- to C-terminal direction: i) a light chain variable region (VL) of an anti-TAA antibody; and j) a light constant region comprising or consisting of the sequence of SEQ ID NO: 299.

[0456] Statement 50. The immunoconjugate may comprise: a) a first polypeptide chain comprising, in an N- to C- terminal direction: i. a heavy chain variable region (VH) of an anti-NKG2D antibody, an anti-NKp30 antibody, an anti- NKp46 antibody, an anti-NKp44 antibody or an anti-DNAM-1 antibody; ii. a human heavy chain constant region comprising or consisting of the sequence of SEQ ID NO: 318 or SEQ ID NO: 324; ill. optionally a linker comprising or consisting of the sequence of SEQ ID NO: 182; iv. an IL-15 receptor alpha (CD215) sushi domain comprising the sequence of SEQ ID NO: 263; v. a linker comprising or consisting of the sequence of SEQ ID NO: 265; and vi. an IL- 15 cytokine comprising or consisting of SEQ ID NO: 151; and b) a second polypeptide chain comprising, in an N- to C-terminal direction: i) a light chain variable region (VL) of an anti-NKG2D antibody, an anti-NKp30 antibody, an anti- NKp46 antibody, an anti-NKp44 antibody or an anti-DNAM-1 antibody; and ii) a light constant region comprising or consisting of the sequence of SEQ ID NO: 326; and c) a third polypeptide chain comprising, in an N- to C-terminal direction i) a heavy chain variable region (VH) of an anti-TAA antibody; ii) a human heavy chain constant region comprising or consisting of the sequence of SEQ ID NO: 319 or SEQ ID NO: 325; d) a fourth polypeptide chain comprising, in an N- to C-terminal direction: i) a light chain variable region (VL) of an anti-TAA antibody; and ii) a light constant region comprising or consisting of the sequence of SEQ ID NO: 326.

[0457] In any of the above statements 43 to 84, the first and second polypeptide chains are covalently or non- covalently associated with each other such that each heavy chain (variable region) and each light chain (variable region) form a first antibody binding domain. The third and fourth polypeptide chains are covalently or non- covalently associated with each other such that each heavy chain (variable region) and each light chain (variable region) form a second antibody binding domain. The resulting first and second antibody binding domains are covalently or non-covalently associated with each other in an immunoglobulin-type format, thereby forming the immunoconjugate comprising the multivalent antibody or antigen binding fragment thereof.

[0458] NKG2D - 1+1+1 (4 chain)

[0459] Statement 51. The immunoconjugate may comprise: a) a first polypeptide chain comprising, in an N- to C- terminal direction: i) a heavy chain variable region (VH) of an anti-NKG2D antibody; ii) a human heavy chain constant region; ill) optionally a linker; iv) an IL-15 receptor alpha (CD215) or a functional fragment thereof; v) optionally a linker; and vi) an IL-15 cytokine; and b) a second polypeptide chain comprising, in an N- to C-terminal direction: i) a light chain variable region (VL) of an anti-NKG2D antibody; and ii) a human light constant region; and c) a third polypeptide chain comprising, in an N- to C-terminal direction i) a heavy chain variable region (VH) of an anti-TAA antibody; ii) a human heavy chain constant region; d) a fourth polypeptide chain comprising, in an N- to C-terminal direction: i) a light chain variable region (VL) of an anti-TAA antibody; and ii) a human light constant region.

[0460] Statement 52. The immunoconjugate may comprise: a) a first polypeptide chain comprising, in an N- to C- terminal direction: i) a heavy chain variable region (VH) of any anti-NKG2D antibody described herein as Hl to H10; ii) a human heavy chain constant region; ill) optionally a linker; iv) an IL-15 receptor alpha (CD215) or a functional fragment thereof; v) optionally a linker; and vi) an IL-15 cytokine; and b) a second polypeptide chain comprising, in an N- to C-terminal direction: i) a light chain variable region (VL) of any anti-NKG2D antibody described herein as LI to LIO; and ii) a human light constant region; and c) a third polypeptide chain comprising, in an N- to C-terminal direction i) a heavy chain variable region (VH) of an anti-TAA antibody; ii) a human heavy chain constant region; d) a fourth polypeptide chain comprising, in an N- to C-terminal direction: i) a light chain variable region (VL) of an anti-TAA antibody; and ii) a human light constant region.

[0461] Statement 53. The immunoconjugate may comprise: a) a first polypeptide chain comprising, in an N- to C- terminal direction: i. a heavy chain variable region (VH) of an anti-NKG2D antibody comprising an HCDR1 comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 1 to 10 and optionally having up to 2 amino acid substitutions thereto, an HCDR2 comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 14 to 23 and optionally having up to 2 amino acid substitutions thereto, and an HCDR3 comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 27 to 36 and optionally having up to 2 amino acid substitutions thereto; ii. a heavy chain constant region comprising or consisting of a sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 95%, at least 97%, at least 98% or at least 99% identity to a sequence selected from the group consisting of SEQ ID NOs: 105, 106, 203 and 314 to 325; ill. optionally a linker; iv. an IL-15 receptor alpha (CD215) or a functional fragment thereof; v. optionally a linker; and vi. an IL-15 cytokine; and b) a second polypeptide chain comprising, in an N- to C-terminal direction: i. a a light chain variable region (VL) of an anti-NKG2D antibody comprising an LCDR1 comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 40 to 49 and optionally having up to 2 amino acid substitutions thereto, an LCDR2 comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 53 to 62 and optionally having up to 2 amino acid substitutions thereto, and an LCDR3 comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 66 to 75 and optionally having up to 2 amino acid substitutions thereto; and ii. a light chain constant region comprising or consisting of a sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 95%, at least 97%, at least 98% or at least 99% identity to a sequence selected from the group consisting of SEQ ID NOs: 107, 108, 299, 310 and 326; and c) a third polypeptide chain comprising, in an N- to C-terminal direction i) a heavy chain variable region (VH) of an anti-TAA antibody; ii) a heavy chain constant region comprising or consisting of a sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 95%, at least 97%, at least 98% or at least 99% identity to a sequence selected from the group consisting of SEQ ID NOs: 105, 106, 203 and 314 to 325; d) a fourth polypeptide chain comprising, in an N- to C-terminal direction: i) a light chain variable region (VL) of an anti-TAA antibody; and ii) a light chain constant region comprising or consisting of a sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 95%, at least 97%, at least 98% or at least 99% identity to a sequence selected from the group consisting of SEQ ID NOs: 107, 108, 299, 310 and 326. The optional amino acid substitutions may be conservative substitutions.

[0462] Statement 54. The immunoconjugate may comprise: a) a first polypeptide chain comprising, in an N- to C- terminal direction: i) a heavy chain variable region ( VH ) of an anti-NKG2D antibody comprising an HCDR1 comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 1 to 10, an HCDR2 comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 14 to 23 and an HCDR3 comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 27 to 36; ii) a heavy chain constant region comprising a CH3 domain comprising one or more amino acid substitutions suitable for knobs-in-holes (KIH) dimerization with the CH3 domain of the third polypeptide chain; ill) optionally a linker; iv) an IL-15 receptor alpha (CD215) or a functional fragment thereof; v) optionally a linker; and vi) an IL-15 cytokine; and b) a second polypeptide chain comprising, in an N- to C-terminal direction: i) a light chain variable region (VL) of an anti-NKG2D antibody comprising an LCDR1 comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 40 to 49, an LCDR2 comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 53 to 62 and an LCDR3 comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 66 to 75; and ii) a light chain constant region; and c) a third polypeptide chain comprising, in an N- to C-terminal direction i) a heavy chain variable region (VH) of an anti-TAA antibody; ii) a human heavy chain constant region comprising a CH3 domain comprising one or more amino acid substitutions suitable for knobs-in-holes (KIH) dimerization with the CH3 domain of the first polypeptide chain; d) a fourth polypeptide chain comprising, in an N- to C-terminal direction: i) a light chain variable region (VL) of an anti-TAA antibody; and ii) a human light constant region.

[0463] Statement 55. The immunoconjugate may comprise: a) a first polypeptide chain comprising, in an N- to C- terminal direction i) a heavy chain variable region ( VH ) of an anti-NKG2D antibody comprising an HCDR1 comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 1 to 10, an HCDR2 comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 14 to 23 and an HCDR3 comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 27 to 36; ii) a heavy chain constant region comprising a CH3 domain comprising or consisting of the sequence of SEQ ID NO: 270; ill) optionally a linker; iv) an IL-15 receptor alpha (CD215) or a functional fragment thereof; v) optionally a linker; and vi) an IL-15 cytokine; and b) a second polypeptide chain comprising, in an N- to C-terminal direction: i) a light chain variable region (VL) of an anti-NKG2D antibody comprising an LCDR1 comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 40 to 49, an LCDR2 comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 53 to 62 and an LCDR3 comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 66 to 75; and ii) a light chain constant region; and c) a third polypeptide chain comprising, in an N- to C-terminal direction i) a heavy chain variable region (VH) of an anti-TAA antibody; ii) a human heavy chain constant region comprising a CH3 domain comprising or consisting of the sequence of SEQ ID NO: 271; d) a fourth polypeptide chain comprising, in an N- to C-terminal direction: i) a light chain variable region (VL) of an anti-TAA antibody; and ii) a human light constant region.

[0464] Statement 56. The immunoconjugate may comprise: a) a first polypeptide chain comprising, in an N- to C- terminal direction: i) a heavy chain variable region (VH) of an anti-NKG2D antibody comprising an HCDR1 comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 1 to 10, an HCDR2 comprising or consisting of a sequence selected from the group consisting of SEQ I D NOs: 14 to 23 and an HCDR3 comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 27 to 36; ii) a heavy chain constant region comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 105, 106, 203 and 314 to 325; ill) optionally a linker; iv) an I L-15 receptor alpha (CD215) or a functional fragment thereof; v) optionally a linker; and vi) an I L-15 cytokine; and b) a second polypeptide chain comprising, in an N- to C-terminal direction: i) a light chain variable region (VL) of an anti-NKG2D antibody comprising an LCDR1 comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 40 to 49, an LCDR2 comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 53 to 62 and an LCDR3 comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 66 to 75; and ii) a light chain constant region comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 107, 108, 299, 310 and 326; and c) a third polypeptide chain comprising, in an N- to C-terminal direction i) a heavy chain variable region (VH) of an anti-TAA antibody; ii) a human heavy chain constant region comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 105, 106, 203 and 314 to 325; d) a fourth polypeptide chain comprising, in an N- to C-terminal direction: i) a light chain variable region (VL) of an anti-TAA antibody; and ii) a human light constant region comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 107, 108, 299, 310 and 326.

[0465] Statement 57. The immunoconjugate may comprise: a) a first polypeptide chain comprising, in an N- to C- terminal direction: i) a heavy chain variable region (VH) of an anti-NKG2D antibody comprising an HCDR1 comprising or consisting of the sequence of SEQ ID NO: 6, an HCDR2 comprising or consisting of the sequence of SEQ ID NO: 19 and an HCDR3 comprising or consisting of the sequence of SEQ ID NO: 32, optionally wherein the VH region comprises or consists of the sequence of SEQ ID NO:84; ii) a heavy chain constant region; iii) optionally a linker; iv) an IL-15 receptor alpha (CD215) or a functional fragmentthereof comprising the sequence of SEQ ID NO: 263; v) optionally a linker; and vi) an IL-15 cytokine comprising or consisting of the sequence of SEQ ID NO: 151; and b) a second polypeptide chain comprising, in an N- to C-terminal direction: i) a light chain variable region (VL) of an anti-NKG2D antibody comprising an LCDR1 comprising or consisting of the sequence of SEQ ID NO: 45, an LCDR2 comprising or consisting of the sequence of SEQ ID NO: 58 and an LCDR3 comprising or consisting of the sequence of SEQ ID NO: 71, optionally wherein the VL region comprises or consists of the sequence of SEQ ID NO: 97; and ii) a light chain constant region; and c) a third polypeptide chain comprising, in an N- to C-terminal direction i) a heavy chain variable region (VH) of an anti-TAA antibody; ii) a human heavy chain constant region; d) a fourth polypeptide chain comprising, in an N- to C-terminal direction: i) a light chain variable region (VL) of an anti-TAA antibody; and ii) a human light constant region.

[0466] Statement 58. The immunoconjugate may comprise: a) a first polypeptide chain comprising, in an N- to C- terminal direction: i) a heavy chain variable region (VH) of an anti-NKG2D antibody comprising an HCDR1 comprising or consisting of the sequence of SEQ ID NO: 6, an HCDR2 comprising or consisting of the sequence of SEQ ID NO: 19 and an HCDR3 comprising or consisting of the sequence of SEQ ID NO: 32, optionally wherein the VH region comprises or consists of the sequence of SEQ ID NO:84; ii) a heavy chain constant region comprising a CH3 domain comprising one or more amino acid substitutions suitable for knobs-in-holes (KIH) dimerization with the CH3 domain of the third polypeptide chain; iii) optionally a linker; iv) an IL-15 receptor alpha (CD215) or a functional fragment thereof; v) optionally a linker; and vi) an IL-15 cytokine; and b) a second polypeptide chain comprising, in an N- to C-terminal direction: i) a light chain variable region (VL) of an anti-NKG2D antibody comprising an LCDR1 comprising or consisting of the sequence of SEQ ID NO: 45, an LCDR2 comprising or consisting of the sequence of SEQ ID NO: 58 and an LCDR3 comprising or consisting of the sequence of SEQ I D NO: 71, optionally wherein the VL region comprises or consists of the sequence of SEQ ID NO: 97; and ii) a light chain constant region; and c) a third polypeptide chain comprising, in an N- to C-terminal direction i) a heavy chain variable region (VH) of an anti-TAA antibody; ii) a human heavy chain constant region comprising a CH3 domain comprising one or more amino acid substitutions suitable for knobs-in-holes (KI H) dimerization with the CH3 domain of the first polypeptide chain; d) a fourth polypeptide chain comprising, in an N- to C-terminal direction: i) a light chain variable region (VL) of an anti-TAA antibody; and ii) a human light constant region.

[0467] Statement 59. The immunoconjugate may comprise: a) a first polypeptide chain comprising, in an N- to C- terminal direction: i) a heavy chain variable region (VH) of an anti-NKG2D antibody comprising an HCDR1 comprising or consisting of the sequence of SEQ ID NO: 6, an HCDR2 comprising or consisting of the sequence of SEQ ID NO: 19 and an HCDR3 comprising or consisting of the sequence of SEQ ID NO: 32, optionally wherein the VH region comprises or consists of the sequence of SEQ ID NO:84; ii) a heavy chain constant region comprising a CH3 domain comprising or consisting of the sequence of SEQ ID NO: 270; ill) optionally a linker; iv) an I L-15 receptor alpha (CD215) or a functional fragment thereof; v) optionally a linker; and vi) an I L-15 cytokine; and b) a second polypeptide chain comprising, in an N- to C-terminal direction: i) a light chain variable region (VL) of an anti-NKG2D antibody comprising an LCDR1 comprising or consisting of the sequence of SEQ ID NO: 45, an LCDR2 comprising or consisting of the sequence of SEQ ID NO: 58 and an LCDR3 comprising or consisting of the sequence of SEQ I D NO: 71, optionally wherein the VL region comprises or consists of the sequence of SEQ ID NO: 97; and ii) a light chain constant region; and c) a third polypeptide chain comprising, in an N- to C-terminal direction i) a heavy chain variable region (VH) of an anti-TAA antibody; ii) a human heavy chain constant region comprising a CH3 domain comprising or consisting of the sequence of SEQ ID NO: 271; d) a fourth polypeptide chain comprising, in an N- to C-terminal direction: i) a light chain variable region (VL) of an anti-TAA antibody; and ii) a human light constant region.

[0468] Statement 60. The immunoconjugate may comprise: a) a first polypeptide chain comprising, in an N- to C- terminal direction: i) a heavy chain variable region (VH) of an anti-NKG2D antibody comprising an HCDR1 comprising or consisting of the sequence of SEQ ID NO: 6, an HCDR2 comprising or consisting of the sequence of SEQ ID NO: 19 and an HCDR3 comprising or consisting of the sequence of SEQ ID NO: 32, optionally wherein the VH region comprises or consists of the sequence of SEQ ID NO:84; ii) a heavy chain constant region comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 105, 106, 203 and 314 to 325; ill) optionally a linker; iv) an I L-15 receptor alpha (CD215) or a functional fragment thereof; v) optionally a linker; and vi) an I L-15 cytokine; and b) a second polypeptide chain comprising, in an N- to C-terminal direction: i) a light chain variable region (VL) of an anti-NKG2D antibody comprising an LCDR1 comprising or consisting of the sequence of SEQ ID NO: 45, an LCDR2 comprising or consisting of the sequence of SEQ ID NO: 58 and an LCDR3 comprising or consisting of the sequence of SEQ ID NO: 71, optionally wherein the VL region comprises or consists of the sequence of SEQ ID NO: 97; and ii) a light chain constant region comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 107, 108, 299, 310 and 326; and c) a third polypeptide chain comprising, in an N- to C-terminal direction i) a heavy chain variable region (VH) of an anti-TAA antibody; ii) a human heavy chain constant region comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 105, 106, 203 and 314 to 325; d) a fourth polypeptide chain comprising, in an N- to C-terminal direction: i) a light chain variable region (VL) of an anti-TAA antibody; and ii) a human light constant region comprising or consisting of a sequence selected from the group consisting of SEQ ID NOs: 107, 108, 299, 310 and 326.

[0469] Statement 61. The immunoconjugate may comprise: a) a first polypeptide chain comprising, in an N- to C- terminal direction: i) a heavy chain variable region (VH) of an anti-NKG2D antibody comprising an HCDR1 comprising or consisting of the sequence of SEQ ID NO: 6, an HCDR2 comprising or consisting of the sequence of SEQ ID NO: 19 and an HCDR3 comprising or consisting of the sequence of SEQ ID NO: 32, opti...

Claims

1. CLAIMS1. An immunoconjugate comprising: a) a multivalent antibody or antigen-binding fragment thereof comprising: i) at least two antibody binding domains wherein:(1) the first antibody binding domain specifically binds to a first target antigen selected from the group consisting of NKG2D, NKp30, NKp46, NKp44 and DNAM-1; and(2) the second antibody binding domain specifically binds to a second, different target antigen; ii) a human immunoglobulin Fc domain comprising:(1) a first chain comprising in an N- to C- terminal direction a CH2 domain and a CH3 domain; and(2) a second chain comprising in an N- to C- terminal direction a CH2 domain and a CH3 domain; and b) at least one I L-15 receptor alpha (CD215) or a functional fragment thereof covalently linked to at least one C-terminus of the Fc domain.

2. The immunoconjugate of any preceding claim, wherein the second antibody binding domain specifically binds to a tumour associated antigen (TAA), optionally HER2, EGFR, CD19, CD20, EGFRvI 11, GD2, PD-L1 or GPC3.

3. The immunoconjugate of any preceding claim, wherein a) the at least one IL-15 receptor alpha (CD215) or a functional fragment thereof is covalently linked to the Fc domain via direct fusion; or b) the at least one IL-15 receptor alpha (CD215) or a functional fragment thereof is covalently linked to the Fc domain via a linker (linker 1), optionally wherein the linker (linker 1) is a peptide of about 5 amino acid residues or less in length, optionally wherein the linker comprises or consists of SEQ ID NO: 182.

4. The immunoconjugate of any preceding claim, wherein the first antibody binding domain comprises: a) a heavy chain variable region (VH) comprising:a HCDR1 comprising or consisting of the sequence of SEQ ID NO: 6, optionally having up to 2 amino acid substitutions therefrom; a HCDR2 comprising or consisting of the sequence of SEQ ID NO: 19, optionally having up to 2 amino acid substitutions therefrom; and a HCDR3 comprising or consisting of the sequence of SEQ ID NO: 32, optionally having up to 2 amino acid substitutions therefrom; and a light chain variable region ( VL) comprising: a LCDR1 comprising or consisting of the sequence of SEQ ID NO: 45, optionally having up to 2 amino acid substitutions therefrom; a LCDR2 comprising or consisting of the sequence of SEQ ID NO: 58, optionally having up to 2 amino acid substitutions therefrom; and a LCDR3 comprising or consisting of the sequence of SEQ ID NO: 71, optionally having up to 2 amino acid substitutions therefrom; b) a heavy chain variable region (VH) comprising: a HCDR1 comprising or consisting of the sequence of SEQ ID NO: 1, optionally having up to 2 amino acid substitutions therefrom; a HCDR2 comprising or consisting of the sequence of SEQ ID NO: 14, optionally having up to 2 amino acid substitutions therefrom; and a HCDR3 comprising or consisting of the sequence of SEQ ID NO: 27, optionally having up to 2 amino acid substitutions therefrom; and a light chain variable region (VL) comprising: a LCDR1 comprising or consisting of the sequence of SEQ ID NO: 40, optionally having up to 2 amino acid substitutions therefrom; a LCDR2 comprising or consisting of the sequence of SEQ ID NO: 53, optionally having up to 2 amino acid substitutions therefrom; and a LCDR3 comprising or consisting of the sequence of SEQ ID NO: 66, optionally having up to 2 amino acid substitutions therefrom; c) a heavy chain variable region (VH) comprising: a HCDR1 comprising or consisting of the sequence of SEQ ID NO: 2, optionally having up to 2 amino acid substitutions therefrom; a HCDR2 comprising or consisting of the sequence of SEQ ID NO: 15, optionally having up to 2 amino acid substitutions therefrom; anda HCDR3 comprising or consisting of the sequence of SEQ ID NO: 28, optionally having up to 2 amino acid substitutions therefrom; and a light chain variable region ( VL) comprising: a LCDR1 comprising or consisting of the sequence of SEQ ID NO: 41, optionally having up to 2 amino acid substitutions therefrom; a LCDR2 comprising or consisting of the sequence of SEQ ID NO: 54, optionally having up to 2 amino acid substitutions therefrom; and a LCDR3 comprising or consisting of the sequence of SEQ ID NO: 67, optionally having up to 2 amino acid substitutions therefrom; d) a heavy chain variable region (VH) comprising: a HCDR1 comprising or consisting of the sequence of SEQ ID NO: 3, optionally having up to 2 amino acid substitutions therefrom; a HCDR2 comprising or consisting of the sequence of SEQ ID NO: 16, optionally having up to 2 amino acid substitutions therefrom; and a HCDR3 comprising or consisting of the sequence of SEQ ID NO: 29, optionally having up to 2 amino acid substitutions therefrom; and a light chain variable region (VL) comprising: a LCDR1 comprising or consisting of the sequence of SEQ ID NO: 42, optionally having up to 2 amino acid substitutions therefrom; a LCDR2 comprising or consisting of the sequence of SEQ ID NO: 55, optionally having up to 2 amino acid substitutions therefrom; and a LCDR3 comprising or consisting of the sequence of SEQ ID NO: 68, optionally having up to 2 amino acid substitutions therefrom; e) a heavy chain variable region (VH) comprising: a HCDR1 comprising or consisting of the sequence of SEQ ID NO: 4, optionally having up to 2 amino acid substitutions therefrom; a HCDR2 comprising or consisting of the sequence of SEQ ID NO: 17, optionally having up to 2 amino acid substitutions therefrom; and a HCDR3 comprising or consisting of the sequence of SEQ ID NO: 30, optionally having up to 2 amino acid substitutions therefrom; and a light chain variable region (VL) comprising: a LCDR1 comprising or consisting of the sequence of SEQ ID NO: 43, optionally having up to 2 amino acid substitutions therefrom;a LCDR2 comprising or consisting of the sequence of SEQ ID NO: 56, optionally having up to 2 amino acid substitutions therefrom; and a LCDR3 comprising or consisting of the sequence of SEQ ID NO: 69, optionally having up to 2 amino acid substitutions therefrom; f) a heavy chain variable region (VH) comprising: a HCDR1 comprising or consisting of the sequence of SEQ ID NO: 5, optionally having up to 2 amino acid substitutions therefrom; a HCDR2 comprising or consisting of the sequence of SEQ ID NO: 18, optionally having up to 2 amino acid substitutions therefrom; and a HCDR3 comprising or consisting of the sequence of SEQ ID NO: 31, optionally having up to 2 amino acid substitutions therefrom; and a light chain variable region ( VL) comprising: a LCDR1 comprising or consisting of the sequence of SEQ ID NO: 44, optionally having up to 2 amino acid substitutions therefrom; a LCDR2 comprising or consisting of the sequence of SEQ ID NO: 57, optionally having up to 2 amino acid substitutions therefrom; and a LCDR3 comprising or consisting of the sequence of SEQ ID NO: 70, optionally having up to 2 amino acid substitutions therefrom; g) a heavy chain variable region (VH) comprising: a HCDR1 comprising or consisting of the sequence of SEQ ID NO: 7, optionally having up to 2 amino acid substitutions therefrom; a HCDR2 comprising or consisting of the sequence of SEQ ID NO: 20, optionally having up to 2 amino acid substitutions therefrom; and a HCDR3 comprising or consisting of the sequence of SEQ ID NO: 33, optionally having up to 2 amino acid substitutions therefrom; and a light chain variable region (VL) comprising: a LCDR1 comprising or consisting of the sequence of SEQ ID NO: 46, optionally having up to 2 amino acid substitutions therefrom; a LCDR2 comprising or consisting of the sequence of SEQ ID NO: 59, optionally having up to 2 amino acid substitutions therefrom; and a LCDR3 comprising or consisting of the sequence of SEQ ID NO: 72, optionally having up to 2 amino acid substitutions therefrom; h) a heavy chain variable region (VH) comprising:a HCDR1 comprising or consisting of the sequence of SEQ ID NO: 8, optionally having up to 2 amino acid substitutions therefrom; a HCDR2 comprising or consisting of the sequence of SEQ ID NO: 21, optionally having up to 2 amino acid substitutions therefrom; and a HCDR3 comprising or consisting of the sequence of SEQ ID NO: 34, optionally having up to 2 amino acid substitutions therefrom; and a light chain variable region ( VL) comprising: a LCDR1 comprising or consisting of the sequence of SEQ ID NO: 47, optionally having up to 2 amino acid substitutions therefrom; a LCDR2 comprising or consisting of the sequence of SEQ ID NO: 60, optionally having up to 2 amino acid substitutions therefrom; and a LCDR3 comprising or consisting of the sequence of SEQ ID NO: 73, optionally having up to 2 amino acid substitutions therefrom; i) a heavy chain variable region (VH) comprising: a HCDR1 comprising or consisting of the sequence of SEQ ID NO: 9, optionally having up to 2 amino acid substitutions therefrom; a HCDR2 comprising or consisting of the sequence of SEQ ID NO: 22, optionally having up to 2 amino acid substitutions therefrom; and a HCDR3 comprising or consisting of the sequence of SEQ ID NO: 35, optionally having up to 2 amino acid substitutions therefrom; and a light chain variable region (VL) comprising: a LCDR1 comprising or consisting of the sequence of SEQ ID NO: 48, optionally having up to 2 amino acid substitutions therefrom; a LCDR2 comprising or consisting of the sequence of SEQ ID NO: 61, optionally having up to 2 amino acid substitutions therefrom; and a LCDR3 comprising or consisting of the sequence of SEQ ID NO: 74, optionally having up to 2 amino acid substitutions therefrom; j) a heavy chain variable region (VH) comprising: a HCDR1 comprising or consisting of the sequence of SEQ ID NO: 10, optionally having up to 2 amino acid substitutions therefrom; a HCDR2 comprising or consisting of the sequence of SEQ ID NO: 23, optionally having up to 2 amino acid substitutions therefrom; anda HCDR3 comprising or consisting of the sequence of SEQ ID NO: 36, optionally having up to 2 amino acid substitutions therefrom; and a light chain variable region ( VL) comprising: a LCDR1 comprising or consisting of the sequence of SEQ ID NO: 49, optionally having up to 2 amino acid substitutions therefrom; a LCDR2 comprising or consisting of the sequence of SEQ ID NO: 62, optionally having up to 2 amino acid substitutions therefrom; and a LCDR3 comprising or consisting of the sequence of SEQ ID NO: 75, optionally having up to 2 amino acid substitutions therefrom; k) a heavy chain variable region (VH) comprising: a HCDR1 comprising or consisting of the sequence of SEQ ID NO: 11, optionally having up to 2 amino acid substitutions therefrom; a HCDR2 comprising or consisting of the sequence of SEQ ID NO: 24, optionally having up to 2 amino acid substitutions therefrom; and a HCDR3 comprising or consisting of the sequence of SEQ ID NO: 37, optionally having up to 2 amino acid substitutions therefrom; and a light chain variable region (VL) comprising: a LCDR1 comprising or consisting of the sequence of SEQ ID NO: 50, optionally having up to 2 amino acid substitutions therefrom; a LCDR2 comprising or consisting of the sequence of SEQ ID NO: 63, optionally having up to 2 amino acid substitutions therefrom; and a LCDR3 comprising or consisting of the sequence of SEQ ID NO: 76, optionally having up to 2 amino acid substitutions therefrom; l) a heavy chain variable region (VH) comprising: a HCDR1 comprising or consisting of the sequence of SEQ ID NO: 12, optionally having up to 2 amino acid substitutions therefrom; a HCDR2 comprising or consisting of the sequence of SEQ ID NO: 25, optionally having up to 2 amino acid substitutions therefrom; and a HCDR3 comprising or consisting of the sequence of SEQ ID NO: 38, optionally having up to 2 amino acid substitutions therefrom; and a light chain variable region (VL) comprising: a LCDR1 comprising or consisting of the sequence of SEQ ID NO: 51, optionally having up to 2 amino acid substitutions therefrom;a LCDR2 comprising or consisting of the sequence of SEQ ID NO: 64, optionally having up to 2 amino acid substitutions therefrom; and a LCDR3 comprising or consisting of the sequence of SEQ ID NO: 77, optionally having up to 2 amino acid substitutions therefrom; or m) a heavy chain variable region (VH) comprising: a HCDR1 comprising or consisting of the sequence of SEQ ID NO: 13, optionally having up to 2 amino acid substitutions therefrom; a HCDR2 comprising or consisting of the sequence of SEQ ID NO: 26, optionally having up to 2 amino acid substitutions therefrom; and a HCDR3 comprising or consisting of the sequence of SEQ ID NO: 39, optionally having up to 2 amino acid substitutions therefrom; and a light chain variable region ( VL) comprising: a LCDR1 comprising or consisting of the sequence of SEQ ID NO: 52, optionally having up to 2 amino acid substitutions therefrom; a LCDR2 comprising or consisting of the sequence of SEQ ID NO: 65, optionally having up to 2 amino acid substitutions therefrom; and a LCDR3 comprising or consisting of the sequence of SEQ ID NO: 78, optionally having up to 2 amino acid substitutions therefrom optionally wherein the optional amino acid substitutions are conservative substitutions.

5. The immunoconjugate of any preceding claim, wherein the first antibody binding domain comprises: a) a VH comprising or consisting of the sequence of SEQ ID NO: 84 and a VL comprising or consisting of the sequence of SEQ ID NO: 97; b) a VH comprising or consisting of the sequence of SEQ ID NO: 79 and a VL comprising or consisting of the sequence of SEQ ID NO: 92; c) a VH comprising or consisting of the sequence of SEQ ID NO: 202 and a VL comprising or consisting of the sequence of SEQ ID NO: 92; d) a VH comprising or consisting of the sequence of SEQ ID NO: 80 and a VL comprising or consisting of the sequence of SEQ ID NO: 93; e) a VH comprising or consisting of the sequence of SEQ ID NO: 81 and a VL comprising or consisting of the sequence of SEQ ID NO: 94; f) a VH comprising or consisting of the sequence of SEQ ID NO: 82 and a VL comprising or consisting of the sequence of SEQ ID NO: 95;g) a VH comprising or consisting of the sequence of SEQ ID NO: 83 and a VL comprising or consisting of the sequence of SEQ ID NO: 96; h) a VH comprising or consisting of the sequence of SEQ ID NO: 85 and a VL comprising or consisting of the sequence of SEQ ID NO: 98; i) a VH comprising or consisting of the sequence of SEQ ID NO: 86 and a VL comprising or consisting of the sequence of SEQ ID NO: 99; j) a VH comprising or consisting of the sequence of SEQ ID NO: 87 and a VL comprising or consisting of the sequence of SEQ ID NO: 100; k) a VH comprising or consisting of the sequence of SEQ ID NO: 88 and a VL comprising or consisting of the sequence of SEQ ID NO: 101; l) a VH comprising or consisting of the sequence of SEQ ID NO: 89 and a VL comprising or consisting of the sequence of SEQ ID NO: 102; m) a VH comprising or consisting of the sequence of SEQ ID NO: 90 and a VL comprising or consisting of the sequence of SEQ ID NO: 103; or n) a VH comprising or consisting of the sequence of SEQ ID NO: 91 and a VL comprising or consisting of the sequence of SEQ ID NO: 104.

6. The immunoconjugate of any preceding claim, wherein the multivalent antibody or antigen binding fragment thereof comprises: a) a heavy chain comprising or consisting of the sequence of SEQ ID NO: 114 and a light chain comprising or consisting of the sequence SEQ ID NO: 140; b) a heavy chain comprising or consisting of the sequence of SEQ ID NO: 109 and a light chain comprising or consisting of the sequence SEQ ID NO: 135; c) a heavy chain comprising or consisting of the sequence of SEQ ID NO: 110 and a light chain comprising or consisting of the sequence SEQ ID NO: 136; d) a heavy chain comprising or consisting of the sequence of SEQ ID NO: 111 and a light chain comprising or consisting of the sequence SEQ ID NO: 137; e) a heavy chain comprising or consisting of the sequence of SEQ ID NO: 112 and a light chain comprising or consisting of the sequence SEQ ID NO: 138; f) a heavy chain comprising or consisting of the sequence of SEQ ID NO: 113 and a light chain comprising or consisting of the sequence SEQ ID NO: 139; g) a heavy chain comprising or consisting of the sequence of SEQ ID NO: 115 and a light chain comprising or consisting of the sequence SEQ ID NO: 141;h) a heavy chain comprising or consisting of the sequence of SEQ ID NO: 116 and a light chain comprising or consisting of the sequence SEQ ID NO: 142; i) a heavy chain comprising or consisting of the sequence of SEQ ID NO: 117 and a light chain comprising or consisting of the sequence SEQ ID NO: 143; j) a heavy chain comprising or consisting of the sequence of SEQ ID NO: 118 and a light chain comprising or consisting of the sequence SEQ ID NO: 144; k) a heavy chain comprising or consisting of the sequence of SEQ ID NO: 119 and a light chain comprising or consisting of the sequence SEQ ID NO: 145; l) a heavy chain comprising or consisting of the sequence of SEQ ID NO: 120 and a light chain comprising or consisting of the sequence SEQ ID NO: 146; m) a heavy chain comprising or consisting of the sequence of SEQ ID NO: 121 and a light chain comprising or consisting of the sequence SEQ ID NO: 147; n) a heavy chain comprising or consisting of the sequence of SEQ ID NO: 122 and a light chain comprising or consisting of the sequence SEQ ID NO: 135; o) a heavy chain comprising or consisting of the sequence of SEQ ID NO: 123 and a light chain comprising or consisting of the sequence SEQ ID NO: 136; p) a heavy chain comprising or consisting of the sequence of SEQ ID NO: 124 and a light chain comprising or consisting of the sequence SEQ ID NO: 137; q) a heavy chain comprising or consisting of the sequence of SEQ ID NO: 125 and a light chain comprising or consisting of the sequence SEQ ID NO: 138; r) a heavy chain comprising or consisting of the sequence of SEQ ID NO: 126 and a light chain comprising or consisting of the sequence SEQ ID NO: 139; s) a heavy chain comprising or consisting of the sequence of SEQ ID NO: 127 and a light chain comprising or consisting of the sequence SEQ ID NO: 140; t) a heavy chain comprising or consisting of the sequence of SEQ ID NO: 128 and a light chain comprising or consisting of the sequence SEQ ID NO: 141; u) a heavy chain comprising or consisting of the sequence of SEQ ID NO: 129 and a light chain comprising or consisting of the sequence SEQ ID NO: 142; v) a heavy chain comprising or consisting of the sequence of SEQ ID NO: 130 and a light chain comprising or consisting of the sequence SEQ ID NO: 143; w) a heavy chain comprising or consisting of the sequence of SEQ ID NO: 131 and a light chain comprising or consisting of the sequence SEQ ID NO: 144;x) a heavy chain comprising or consisting of the sequence of SEQ ID NO: 132 and a light chain comprising or consisting of the sequence SEQ ID NO: 145; y) a heavy chain comprising or consisting of the sequence of SEQ ID NO: 133 and a light chain comprising or consisting of the sequence SEQ ID NO: 146; or z) a heavy chain comprising or consisting of the sequence of SEQ ID NO: 134 and a light chain comprising or consisting of the sequence SEQ ID NO: 147.

7. The immunoconjugate of any preceding claim, wherein the second antibody binding domain specifically binds to HER2 and comprises: a) a heavy chain variable region (VH) comprising i) a HCDR1 comprising or consisting of the sequence of SEQ ID NO: 330, optionally having up to 2 amino acid substitutions therefrom; ii) a HCDR2 comprising or consisting of the sequence of SEQ ID NO: 331, optionally having up to 2 amino acid substitutions therefrom; and ill) a HCDR3 comprising or consisting of the sequence of SEQ ID NO: 332, optionally having up to 2 amino acid substitutions therefrom; b) and a light chain variable region (VL) comprising: i) a LCDR1 comprising or consisting of the sequence of SEQ ID NO: 333, optionally having up to 2 amino acid substitutions therefrom; ii) a LCDR2 comprising or consisting of the sequence of SEQ ID NO: 334, optionally having up to 2 amino acid substitutions therefrom; and ill) a LCDR3 comprising or consisting of the sequence of SEQ ID NO: 335, optionally having up to 2 amino acid substitutions therefrom; optionally wherein the optional amino acid substitutions are conservative substitutions.

8. The immunoconjugate of any preceding claim, wherein the second antibody binding domain specifically binds to HER2 and comprises a VH comprising or consisting of the sequence of SEQ ID NO: 304 and a VL domain comprising or consisting of the sequence of SEQ ID NO: 305.

9. The immunoconjugate of any preceding claim, wherein a) the first antibody binding domain specifically binds to NKG2D and comprises a VH comprising or consisting of the sequence of SEQ ID NO: 84 and a VL comprising or consisting of the sequence of SEQ ID NO: 97; andb) the second antibody binding domain specifically binds to HER2 and comprises a VH comprising or consisting of the sequence of SEQ ID NO: 304 and a VL domain comprising or consisting of the sequence of SEQ ID NO: 305.

10. The immunoconjugate of any preceding claim, wherein the first antibody binding domain competes with the antibody 21F2 for binding to human NKG2D and MICA / MICB.

11. The immunoconjugate of any preceding claim, wherein a) the CH3 domain of the first chain is engineered to heterodimerise with the CH3 domain of the second chain, optionally wherein the CH3 domain of the first chain comprises the mutations S354C and T366W (EU numbering); and / or b) the CH3 domain of the second chain is engineered to heterodimerise with the CH3 domain of the first chain, optionally wherein the CH3 domain of the second chain comprises the mutations Y349C, T366S, L368A, and Y407V (EU numbering).

12. The immunoconjugate of any preceding claim, wherein the CH3 domain of the first chain comprises or consists of the sequence of SEQ ID NO: 270 and / or the CH3 domain of the second chain comprises or consists of the sequence of SEQ ID NO: 271.

13. The immunoconjugate of any preceding claim, wherein the Fc domain is Fc disabled14. The immunoconjugate of any preceding claim, wherein the IL-15 receptor alpha (CD215) fragment(s) comprise the IL-15 receptor alpha (CD215) sushi domain, optionally wherein the IL-15 receptor alpha (CD215) sushi domain(s) is a human IL-15 receptor alpha (CD215) sushi domain(s).

15. The immunoconjugate of claim 14, wherein the IL-15 receptor alpha (CD215) sushi domain comprises or consists of a sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 95%, at least 97%, at least 98%, at least 99% identity or 100% identity to a sequence selected from the group consisting of SEQ ID NOs: 149 to 150, 263 or 264.

16. The immunoconjugate of any preceding claim, wherein the immunoconjugate comprises one IL-15 receptor alpha (CD215) or a functional fragment thereof covalently linked to the C-terminus of the first chain or the second chain of the Fc domain.

17. The immunoconjugate of any preceding claim, wherein the immunoconjugate comprises a first IL-15 receptor alpha (CD215) or a functional fragment thereof covalently linked to the C-terminus of the first chain of the Fc domain and a second IL-15 receptor alpha (CD215) or a functional fragment thereof covalently linked to the C-terminus of the second chain of the Fc domain.

18. The immunoconjugate of any preceding claim, further comprising at least one human IL-15 cytokine or a functional fragment thereof covalently linked to the C-terminus of at least one IL-15 receptor alpha (CD215) or functional fragment thereof.

19. The immunoconjugate of any previous claim, wherein a) the IL-15 cytokine and the IL-15 receptor alpha (CD215) or functional fragment thereof are directly fused to each other; or b) the IL-15 cytokine and the IL-15 receptor alpha (CD215) or functional fragment thereof are joined by a linker (linker 2), optionally wherein the linker (linker 2) is a peptide of from about 30 to about 60 amino acid residues in length, optionally wherein the linker (linker 2) comprises or consists of SEQ ID NO: 265.

20. The immunoconjugate of any previous claim, comprising a) a first polypeptide chain comprising, in an N- to C- terminal direction: i) a heavy chain variable region (VH) of an anti-NKG2D antibody, optionally SEQ ID NO: 84; ii) a human heavy chain constant region, optionally comprising the sequence of SEQ ID NO: 270; ill) optionally a linker; iv) an IL- 15 receptor alpha (CD215) or a functional fragment thereof, optionally comprising the sequence of SEQ ID NO: 263; v) optionally a linker, optionally comprising the sequence of SEQ ID NO: 265; and vi) an IL-15 cytokine; and b) a second polypeptide chain comprising, in an N- to C-terminal direction: i) a light chain variable region (VL) of an anti-NKG2D antibody, optionally SEQ ID NO: 97; and ii) a human light constant region; and c) a third polypeptide chain comprising, in an N- to C-terminal direction i) a heavy chain variable region (VH) of an anti-TAA antibody;ii) a human heavy chain constant region, optionally comprising the sequence of SEQ ID NO: 271; ill) optionally a linker; iv) an IL- 15 receptor alpha (CD215) or a functional fragment thereof, optionally comprising the sequence of SEQ ID NO: 263; v) optionally a linker, optionally comprising the sequence of SEQ ID NO: 265; and vi) an IL-15 cytokine; and d) a fourth polypeptide chain comprising, in an N- to C-terminal direction: i) a light chain variable region (VL) of an anti-TAA antibody; and ii) a human light constant region.

21. The immunoconjugate of any previous claim, comprising: a) a first polypeptide chain comprising, in an N- to C- terminal direction: i) a heavy chain variable region (VH) of an anti-NKG2D antibody optionally SEQ ID NO: 84; ii) a human heavy chain constant region optionally comprising the sequence of SEQ ID NO: 270; ill) optionally a linker; iv) an IL- 15 receptor alpha (CD215) or a functional fragment thereof, optionally comprising the sequence of SEQ ID NO: 263; v) optionally a linker, optionally comprising the sequence of SEQ ID NO: 265; and vi) an IL-15 cytokine; and b) a second polypeptide chain comprising, in an N- to C-terminal direction: i) a light chain variable region (VL) of an anti-NKG2D antibody, optionally SEQ ID NO: 97; and ii) a human light constant region; and c) a third polypeptide chain comprising, in an N- to C-terminal direction i) a heavy chain variable region (VH) of an anti-TAA antibody; ii) a human heavy chain constant region, optionally comprising the sequence of SEQ ID NO: 270; d) a fourth polypeptide chain comprising, in an N- to C-terminal direction: i) a light chain variable region (VL) of an anti-TAA antibody; and ii) a human light constant region.

22. The immunoconjugate of any one of claims 1 to 17, wherein the immunoconjugate does not comprise a covalently linked IL-15 cytokine.

23. The immunoconjugate of any one of claims 1 to 17, wherein the immunoconjugate comprises one or more human IL-15 cytokine(s) or fragment(s) thereof non-covalently bound to one or more IL-15 receptor alpha (CD215) or a functional fragment thereof.

24. The immunoconjugate of any preceding claim, wherein the IL-15 cytokine comprises or consists of a sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 95%, at least 97%, at least 98%, at least 99% identity or 100% identity to a sequence selected from the group consisting of SEQ ID NOs: 151 to 153 and 285, preferably SEQ ID NO: 151.

25. The immunoconjugate of any preceding claim, comprising a sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 95%, at least 97%, at least 98%, at least 99% identity or at least 100% identity to a sequence selected from the group consisting of SEQ ID NOs: 154, 155, 206, 207, 327, 328 and 329.

26. An immunoconjugate as described in any one of Statements 1 to 150.

27. The immunoconjugate of any previous claim, comprising: a) a first polypeptide chain comprising, in an N- to C- terminal direction: i. a heavy chain variable region ( VH ) of an anti-NKG2D antibody, optionally SEQ ID NO: 84; ii. a human heavy chain constant region, optionally comprising the sequence of SEQ ID NO: 270; ill. optionally a linker; iv. an IL-15 receptor alpha (CD215) or a functional fragment thereof, optionally comprising the sequence of SEQ ID NO: 263; b) a second polypeptide chain comprising, in an N- to C-terminal direction: i. a light chain variable region (VL) of an anti-NKG2D antibody, optionally SEQ ID NO: 97; and ii. a human light constant region; and c) a third polypeptide chain comprising, in an N- to C-terminal direction i. a heavy chain variable region (VH) of an anti-TAA antibody;ii. a human heavy chain constant region, optionally comprising the sequence of SEQ ID NO: 271; ill. optionally a linker; iv. an IL-15 receptor alpha (CD215) or a functional fragment thereof, optionally comprising the sequence of SEQ ID NO: 263; d) a fourth polypeptide chain comprising, in an N- to C-terminal direction: i. a light chain variable region (VL) of an anti-TAA antibody; and ii. a human light constant region; e) optionally a fifth and sixth polypeptide chain, each comprising or consisting of a human IL- 15 cytokine as described herein.

28. The immunoconjugate of any previous claim, comprising: a) a first polypeptide chain comprising, in an N- to C- terminal direction: i. a heavy chain variable region (VH) of an anti-NKG2D antibody, optionally SEQ ID NO: 84; ii. a human heavy chain constant region, optionally comprising the sequence of SEQ ID NO: 270; ill. optionally a linker; iv. an IL-15 receptor alpha (CD215) or a functional fragment thereof, optionally comprising the sequence of SEQ ID NO: 263; b) a second polypeptide chain comprising, in an N- to C-terminal direction: i. a light chain variable region (VL) of an anti-NKG2D antibody, optionally SEQ ID NO: 97; and ii. a human light constant region; and c) a third polypeptide chain comprising, in an N- to C-terminal direction i. a heavy chain variable region (VH) of an anti-TAA antibody; ii. a human heavy chain constant region, optionally comprising the sequence of SEQ ID NO: 271; d) a fourth polypeptide chain comprising, in an N- to C-terminal direction: i. a light chain variable region (VL) of an anti-TAA antibody; and ii. a human light constant region; e) optionally a fifth polypeptide chain, comprising or consisting of a human IL-15 cytokine as described herein.

29. The immunoconjugate of claims 19, 20, 26 or 27 wherein the anti-TAA antibody is an anti-HER2 antibody.

30. A polynucleotide, pair of polynucleotides or set of polynucleotides encoding the immunoconjugate of any preceding claim.

31. A vector comprising a polynucleotide, pair of polynucleotides or set of polynucleotides of claim 30.

32. A host cell comprising a polynucleotide, pair of polynucleotides or set of polynucleotides of claim 30, or a vector of claim 31.

33. A method of treating a disease, optionally wherein the disease is cancer, comprising administering to a subject in need thereof a therapeutically effective amount of an immunoconjugate of any preceding claim.

34. An immunoconjugate comprising: a) a first polypeptide chain comprising, in an N- to C-terminal direction: i. a heavy chain variable region (VH) of an anti-NKG2D antibody, an anti-NKp30 antibody, an anti-NKp46 antibody, an anti-NKp44 antibody or an anti-DNAM-1 antibody; ii. a human heavy chain constant region; ill. optionally a linker comprising or consisting of the sequence of SEQ ID NO: 182; and iv. the IL-15 polypeptide comprising i. an IL-15 receptor alpha (CD215) or a functional fragment thereof; ii. a linker comprising or consisting of the sequence of SEQ ID NO: 265; and ill. an IL-15 cytokine; and b) a second polypeptide chain comprising, in an N- to C-terminal direction: i. a light chain variable region (VL) of an anti-NKG2D antibody, an anti-NKp30 antibody, an anti- NKp46 antibody, an anti-NKp44 antibody or an anti-DNAM-1 antibody; and ii. a human light constant region; and the immunoconjugate comprises or consists of first and second copies of said first and second polypeptides35. An immunoconjugate comprising: a) a first polypeptide chain comprising, in an N- to C-terminal direction:i) a heavy chain variable region (VH) of an anti-NKG2D antibody, an anti-NKp30 antibody, an anti-NKp46 antibody, an anti-NKp44 antibody or an anti-DNAM-1 antibody; ii) a human heavy chain constant region; iii) optionally a linker; and iv) an IL- 15 receptor alpha (CD215) or a functional fragment thereof; and b) a second polypeptide chain comprising, in an N- to C-terminal direction: i) a light chain variable region (VL) of an anti-NKG2D antibody, an anti-NKp30 antibody, an anti-NKp46 antibody, an anti-NKp44 antibody or an anti-DNAM-1 antibody; and ii) a human light constant region; and the immunoconjugate comprises or consists of first and second copies of said first and second polypeptides; and optionally a fifth and sixth polypeptide chain, each comprising or consisting of a human IL- 15 cytokine.

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