compounds

Abstract

Compounds of formula (I-Y), (II-Y) and (III-Y): wherein U, A, X, R1, R2, R3, R4, R5, L, Y, BM and q have the meanings defined herein, are provided. Processes for preparing the compounds and their used in a variety of medical applications, in particular in the treatment of cancer, are also provided.

Description

[0001] COMPOUNDS

[0002] Field of the Invention

[0003] This invention relates to novel pharmaceutically useful compounds, which compounds are useful as anti-tumour agents, and to linker-payload compounds and binding molecule -linker - payload conjugates, such as antibody-drug conjugates (ADCs) containing the compounds as the payload moiety. The invention also relates to the use of such compounds as medicaments, to the use of such compounds for in vitro, in situ and in vivo diagnosis or treatment of mammalian cells (or associated pathological conditions), to pharmaceutical compositions containing them, and to synthetic routes fortheir production.

[0004] Background

[0005] Antibody-drug conjugates (ADCs) have prompted a revolution in the treatment of cancer. ADCs, comprising monoclonal antibodies conjugated to cytotoxic agents (payloads) via a cleavable linker, have emerged as novel therapeutic options. Upon binding with the cell surface antigen targeted by the specific antibody, the ADC is internalized by the tumour cell and processed by the endo-lysosomal system. Within the tumour cognate antigen-positive cells are bound by the antibody, the payload is released through the cleavable linker technology and results in cytotoxic activity.

[0006] ADCs can induce tumour cell death through the so-called bystander effect, which occurs when the cytotoxic payload (warhead) diffuses across the cell membrane to neighbouring cells, thus inducing their apoptosis. ADCs interact with cancer and immune cells by eliciting mechanisms such as immunogenic cell death, antibody-dependent cell-mediated cytotoxicity and dendritic cell activation.

[0007] An example of an ADC approved as a human medicine is trastuzumab deruxtecan (Enhertu®), which contains deruxtecan as the linker-payload moiety and the DNA topoisomerase I inhibitor referred to herein as “Dxd” as the payload moiety. However, there remains a need in the art to develop improved payloads and ADCs containing them.

[0008] Summary of the Invention

[0009] In a first aspect, there is provided a compound of formula (I):

[0010]

[0011] or a pharmaceutically acceptable salt or solvate thereof,

[0012] wherein:

[0013] II is O or S;

[0014] X is a bond, O, S, S(=O) or S(=O)2;

[0015] when X is O, S, S(=O) or S(=O)2, A is C2-10 alkylene, C2-10 alkenylene, C2- alkynylene, C3-10 cycloalkylene, C3-10 cycloalkenylene, Cs- cycloalkynylene, C3-10 heterocycloalkylene, C3-10 heterocycloalkenylene, or Cs- heterocycloalkynylene, each optionally substituted by one or more substituents selected from List 1;

[0016] when X is a bond, A is C1-10 alkylene, C2-10 alkenylene, C2- alkynylene, C3-10 cycloalkylene, C3-10 cycloalkenylene, Cs- cycloalkynylene, C3-10 heterocycloalkylene, C3-10 heterocycloalkenylene, or Cs- heterocycloalkynylene, each optionally substituted by one or more substituents selected from List 1;

[0017] R1 and R4 are each independently H or C1-6 alkyl, or R1 and R4 together with the carbon atoms to which they are attached form a 5- to 7-membered carbocyclic ring which is substituted by a group -NH-C(=O)-Rs;

[0018] R2 is H, halogen or C1-6 alkyl;

[0019] R3 is C1-6 alkyl; and

[0020] Rs is C1-6 alkyl or -NR’R”, where R’ and R” are each independently H or C1-6 alkyl.

[0021] The compounds of formula (I) are also referred to generally herein as “payload” compounds. This term generally covers the compounds either in their own right or when forming the payload part of a linker-payload or binding molecule-linker-payload conjugate as defined below.

[0022] In a second aspect, there is provided a compound of formula (II):

[0023]

[0024] or a pharmaceutically acceptable salt or solvate thereof,

[0025] wherein:

[0026] X, II, A, Ri, R2, R3, R4 and Rs are as defined above for formula (I);

[0027] L is a linker; and

[0028] Y is a group capable of conjugating with a binding molecule to generate a conjugate.

[0029] The compounds of formula (II) are also referred to generally herein as “linker-payload” compounds. This term generally covers the compounds either in their own right or when forming the linker-payload part of a binding molecule-linker-payload conjugate as defined below.

[0030] In a third aspect, there is provided a compound of formula (III):

[0031]

[0032] or a pharmaceutically acceptable salt or solvate thereof, wherein:

[0033] BM is a binding molecule or a fragment thereof;

[0034] X, II, A, Ri, R2, R3, R4 and Rs are as defined herein;

[0035] L is a linker as defined herein; and

[0036] q is an integer from 1 to 16.

[0037] The compounds of formula (III) are also referred to generally herein as “binding molecule-linker-payload” compounds. When the binding molecule BM is an antibody or a fragment thereof, the compounds are also referred to herein as “antibody-drug conjugates” or “ADCs”.

[0038] In a fourth aspect, there is provided a composition comprising a compound of formula (III’):

[0039]

[0040] or a pharmaceutically acceptable salt thereof, wherein:

[0041] BM is a binding molecule or a fragment thereof;

[0042] X, II, A, R1 , R2, R3, R4 and Rs are as defined herein;

[0043] L is a linker as defined herein; and

[0044] q’ is an integer or a decimal from 1 to 16.

[0045] In another aspect of the invention, there is provided a pharmaceutical formulation including a compound of formula (I), (II) or (III) as defined herein, or a pharmaceutically acceptable solvate or salt thereof, or a composition containing a compound of formula (III’) as defined herein or a pharmaceutically acceptable solvate or salt thereof, in admixture with a pharmaceutically acceptable adjuvant, diluent or carrier.In another aspect of the invention, there is provided a compound of formula (I), (II) or (III) as defined herein, or a pharmaceutically acceptable solvate or salt thereof, or a composition containing a compound of formula (III’) as defined herein ora pharmaceutically acceptable solvate or salt thereof, for use as a medicament.

[0046] In a further aspect of the present invention, there is provided a compound of formula (I), (II) or (III) as defined herein, or a pharmaceutically acceptable solvate or salt thereof, or a composition containing a compound of formula (III’) as defined herein ora pharmaceutically acceptable solvate or salt thereof, for use in the treatment of cancer.

[0047] In a further aspect of the present invention, there is provided use of a compound of formula (I), (II) or (III) as defined herein, or a pharmaceutically acceptable solvate or salt thereof, or a composition containing a compound of formula (III’) as defined herein ora pharmaceutically acceptable solvate or salt thereof, in the manufacture of a medicament for the treatment of cancer.

[0048] In a further aspect of the present invention, there is provided a method of treatment of cancer, which method comprises administration of a therapeutically effective amount a compound of formula (I), (II) or (III) as defined herein, or a pharmaceutically acceptable solvate or salt thereof, or a composition containing a compound of formula (III’) as defined herein or a pharmaceutically acceptable solvate or salt thereof, to a patient suffering from, or susceptible to, such a condition.

[0049] In a fifth aspect, there is provided a compound of formula (l-Y):

[0050]

[0051] or a pharmaceutically acceptable salt or solvate thereof,

[0052] wherein:

[0053] II is O or S;

[0054] X is O, S, S(=O) or S(=O)2;

[0055] A is C2-10 alkylene, C2-10 alkenylene, C2- alkynylene, C3-10 cycloalkylene, C3-10 cycloalkenylene, Cs- cycloalkynylene, C3-10 heterocycloalkylene, C3-10 heterocycloalkenylene, or Cs- heterocycloalkynylene, each optionally substituted with one or more substituents selected from List 1 ;

[0056] either: R1 is C1-6 alkyl, and R4 is H or C1-6 alkyl,

[0057] or: R1 and R4 together with the carbon atoms to which they are attached form a 5- to 7-membered carbocyclic ring which is substituted by a group -NH-C(=O)-Rs;

[0058] R2 is halogen or C1-6 alkyl;

[0059] R3 is C1-6 alkyl; and

[0060] Rs is C1-6 alkyl or-NR’R”, wherein R’ and R” are each independently H or C1-6 alkyl; provided that when X is O and R1 is ethyl, A is not C2-3 alkylene.

[0061] The compounds of formula (l-Y) are also referred to generally herein as “payload” compounds. This term generally covers the compounds either in their own right or when forming the payload part of a linker-payload or binding molecule-linker-payload conjugate as defined below.

[0062] In a sixth aspect, there is provided a compound of formula (ll-Y):

[0063]

[0064] or a pharmaceutically acceptable salt or solvate thereof,

[0065] wherein:II is O or S;

[0066] X is a bond, O, S, S(=O) or S(=O)2;

[0067] when X is O, S, S(=O) or S(=O)2, A is C2-10 alkylene, C2-10 alkenylene, C2- alkynylene, C3-10 cycloalkylene, C3-10 cycloalkenylene, Cs- cycloalkynylene, C3-10 heterocycloalkylene, C3-10 heterocycloalkenylene, or Cs- heterocycloalkynylene, each optionally substituted with one or more substituents selected from List 1 ;

[0068] when X is a bond, A is C1-10 alkylene, C2-10 alkenylene, C2- alkynylene, C3-10 cycloalkylene, C3-10 cycloalkenylene, Cs- cycloalkynylene, C3-10 heterocycloalkylene, C3-10 heterocycloalkenylene, or Cs- heterocycloalkynylene, each optionally substituted with one or more substituents selected from List 1 ;

[0069] R1 and R4 are each independently H or C1-6 alkyl;

[0070] or R1 and R4 together with the carbon atoms to which they are attached form a 5- to 7-membered carbocyclic ring which is substituted by a group -NH-C(=O)-Rs;

[0071] R2 is H, halogen or C1-6 alkyl;

[0072] R3 is C1-6 alkyl; and

[0073] Rs is C1-6 alkyl or-NR’R”, wherein R’ and R” are each independently H or C1-6 alkyl;

[0074] L is a linker of formula (LX):

[0075]

[0076] wherein:

[0077] R is C1-6 alkyl;

[0078] EO is an ethylene glycol moiety, the terminal carbon of which is attached to the group -N(R)-and the terminal oxygen of which is attached to the group -(CH2)W- when w is 1 to 10, or to the - C(=O) group when w is 0;

[0079] v is 0 or 1 to 40;

[0080] w is 0 or 1 to 10;

[0081] P is a peptide moiety consisting of 1 to 10 amino acid residues;

[0082] Re and R? are each independently H or C1-6 alkyl, or Re and R? together with the carbon atom to which they are attached form a 3- to 10-membered carbocyclic ring;

[0083] position (1) is bonded to the group Y; and

[0084] position (2) is bonded to the U atom of the -L-U- moiety; and

[0085] Y is a group capable of conjugating with a binding molecule to generate a conjugate.The compounds of formula (I l-Y) are also referred to generally herein as “linker-payload” compounds. This term generally covers the compounds either in their own right or when forming the linker-payload part of a binding molecule-linker-payload conjugate as defined below.

[0086] In a seventh aspect, there is provided a compound of formula (I I l-Y):

[0087]

[0088] or a pharmaceutically acceptable salt or solvate thereof, wherein:

[0089] BM is a binding molecule or a fragment thereof;

[0090] X, II, A, Ri, R2, R3, R4 and Rs are as defined herein;

[0091] L is a linker as defined herein; and

[0092] q is an integer from 1 to 16.

[0093] The compounds of formula (lll-Y) are also referred to generally herein as “binding molecule-linker-payload” compounds. When the binding molecule BM is an antibody or a fragment thereof, the compounds are also referred to herein as “antibody-drug conjugates” or “ADCs”.

[0094] In an eighth aspect, there is provided a composition comprising a compound of formula (III-Y’):

[0095]

[0096] or a pharmaceutically acceptable salt thereof, wherein:

[0097] BM is a binding molecule or a fragment thereof;

[0098] X, II, A, R1 , R2, R3, R4 and Rs are as defined herein;

[0099] L is a linker as defined herein; and

[0100] q’ is an integer or a decimal from 1 to 16.

[0101] In another aspect, there is provided a compound of formula (ll-YY):

[0102]

[0103] or a pharmaceutically acceptable salt or solvate thereof,

[0104] wherein:

[0105] X, II, A, Ri, R2, R3, R4 and Rs are as defined herein for formula (l-Y);

[0106] L is a linker; and

[0107] Y is a group capable of conjugating with a binding molecule to generate a conjugate.

[0108] In another aspect, there is provided a compound of formula (l-B):

[0109]

[0110] or a pharmaceutically acceptable salt or solvate thereof,

[0111] wherein:

[0112] II is O or S;

[0113] X is O, S, S(=O), orS(=O)2;

[0114] A is C2-10 alkylene, C2-10 alkenylene, C2- alkynylene, C3-10 cycloalkylene, C3-10 cycloalkenylene, Cs- cycloalkynylene, C3-10 heterocycloalkylene, C3-10 heterocycloalkenylene, or Cs- heterocycloalkynylene, each optionally substituted with one or more substituents selected from List 1 ;

[0115] either: R1 is Me or C3-6 cycloalkyl, and R4 is H or C1-6 alkyl,

[0116] or: R1 and R4 together with the carbon atoms to which they are attached form a 5- to 7-membered carbocyclic ring which is substituted by a group -NH-C(=O)-Rs;

[0117] R2 is halogen or C1-6 alkyl;

[0118] R3 is C1-6 alkyl; and

[0119] Rs is C1-6 alkyl or-NR’R”, wherein R’ and R” are each independently H or C1-6 alkyl.

[0120] In another aspect, there is provided a compound of formula (l-C):

[0121]

[0122] or a pharmaceutically acceptable salt or solvate thereof,wherein:

[0123] II is O or S;

[0124] X is S, S(=O), orS(=O)2;

[0125] A is C2-10 alkylene, C2-10 alkenylene, C2- alkynylene, C3-10 cycloalkylene, C3-10 cycloalkenylene, Cs- cycloalkynylene, C3-10 heterocycloalkylene, C3-10 heterocycloalkenylene, or Cs- heterocycloalkynylene, each optionally substituted with one or more substituents selected from List 1 ;

[0126] either: R1 is H, C1-6 alkyl or C3-6 cycloalkyl, and R4 is H or C1-6 alkyl,

[0127] or: R1 and R4 together with the carbon atoms to which they are attached form a 5- to 7-membered carbocyclic ring which is substituted by a group -NH-C(=O)-Rs;

[0128] R2 is halogen or C1-6 alkyl;

[0129] R3 is C1-6 alkyl; and

[0130] Rs is C1-6 alkyl or-NR’R”, wherein R’ and R” are each independently H or C1-6 alkyl.

[0131] In another aspect, the invention relates to a compound of formula (l-D):

[0132]

[0133] or a pharmaceutically acceptable salt or solvate thereof,

[0134] wherein:

[0135] II is O or S;

[0136] X is a bond;

[0137] A is C2-10 alkylene, C2-10 alkenylene, C2- alkynylene, C3-10 cycloalkylene, C3-10 cycloalkenylene, Cs- cycloalkynylene, C3-10 heterocycloalkylene, C3-10 heterocycloalkenylene, or Cs- heterocycloalkynylene, each optionally substituted with one or more substituents selected from List 1 ;

[0138] R1 is H, C2-6 alkyl or C3-6 cycloalkyl;

[0139] R4 is H or C1-6 alkyl;or Ri and R4 together with the carbon atoms to which they are attached form a 5- to 7-membered carbocyclic ring which is substituted by a group -NH-C(=O)-Rs;

[0140] R2 is halogen or C1-6 alkyl;

[0141] R3 is C1-6 alkyl; and

[0142] Rs is C1-6 alkyl or-NR’R”, wherein R’ and R” are each independently H or C1-6 alkyl.

[0143] Further aspects of the invention relate to linker-payload compounds comprising a compound of formula (l-B), (l-C) or (l-D) as described herein, for example, compounds of formula (I l-B) , (I l-C) or (I l-D) as described herein.

[0144] Further aspects of the invention relate to binding molecule-linker-payload compounds comprising a compound of formula (ll-YY), (l-B), (l-C) or (l-D) as described herein, for example, compounds of formula (I ll-YY), (I I l-B), (lll-C) or (I I l-D) as described herein.

[0145] Further aspects of the invention relate to compositions comprising binding molecule-linker-payload compounds of formula (I I l-YY’), (I I l-B’), (lll-C’) or (I I l-D’) as described herein

[0146] In another aspect of the invention, there is provided a pharmaceutical formulation including a compound of formula (l-Y), (l-A), (l-B), (l-C), (l-D), (ll-Y), (ll-YY), (ll-A), (ll-B), (ll-C), (ll-D), (lll-Y), (I I l-YY), (I I l-A), (I I l-B), (lll-C) or (I I l-D) as defined herein, or a pharmaceutically acceptable solvate or salt thereof, or a composition containing a compound of formula (III-Y'), (I I l-YY’), (I I l-A’), (I I l-B’), (lll-C’) or (I I l-D’) as defined herein or a pharmaceutically acceptable solvate or salt thereof, in admixture with a pharmaceutically acceptable adjuvant, diluent or carrier.

[0147] In another aspect of the invention, there is provided a compound of formula (l-Y), (l-A), (l-B), (l-C), (l-D), (ll-Y), (ll-YY), (ll-A), (ll-B), (ll-C), (ll-D), (lll-Y), (lll-YY), (lll-A), (lll-B), (lll-C) or (III-D) as defined herein, or a pharmaceutically acceptable solvate or salt thereof, or a composition containing a compound of formula (lll-Y’), (lll-YY’), (lll-A’), (lll-B’), (lll-C’) or (III-D’) as defined herein or a pharmaceutically acceptable solvate or salt thereof, for use as a medicament.

[0148] In a further aspect of the present invention, there is provided a compound of formula (l-Y), (I-A), (l-B), (l-C), (l-D), (ll-Y), (ll-YY), (ll-A), (ll-B), (ll-C), (ll-D), (lll-Y), (lll-YY), (lll-A), (lll-B), (III-C) or (I I l-D) as defined herein, or a pharmaceutically acceptable solvate or salt thereof, or a composition containing a compound of formula (lll-Y’), (lll-YY’), (lll-A’), (lll-B’), (lll-C’) or (III-D’) as defined herein or a pharmaceutically acceptable solvate or salt thereof, for use in the treatment of cancer.

[0149] In a further aspect of the present invention, there is provided use of a compound of formula (l-Y), (l-A), (l-B), (l-C), (l-D), (ll-Y), (ll-YY), (ll-A), (ll-B), (ll-C), (ll-D), (lll-Y), (lll-YY), (lll-A), (lll-B), (I I l-C) or (I I l-D) as defined herein, or a pharmaceutically acceptable solvate or salt thereof, ora composition containing a compound of formula (lll-Y’), (lll-YY’), (lll-A’), (lll-B’), (I I l-C’) or (I I l-D’) as defined herein or a pharmaceutically acceptable solvate or salt thereof, in the manufacture of a medicament for the treatment of cancer.

[0150] In a further aspect of the present invention, there is provided a method of treatment of cancer, which method comprises administration of a therapeutically effective amount a compound of formula (l-Y), (l-A), (l-B), (l-C), (l-D), (ll-Y), (ll-YY), (ll-A), (ll-B), (ll-C), (ll-D), (lll-Y), (lll-YY), (lll-A), (lll-B), (I I l-C) or (I I l-D) as defined herein, or a pharmaceutically acceptable solvate or salt thereof, or a composition containing a compound of formula (III-Y’), (lll-YY’), (lll-A’), (lll-B’), (I I l-C’) or (I I l-D’) as defined herein or a pharmaceutically acceptable solvate or salt thereof, to a patient suffering from, or susceptible to, such a condition.

[0151] Advantages

[0152] It has been found by the present inventors that the compounds of the present invention exhibit potent anti-tumour activity against a variety of cancer cell lines. In some embodiments, the compounds of formula (I) exhibit improved anti-tumour activity compared with the DNA topoisomerase I inhibitor referred to herein as “Dxd”. These payload compounds can be incorporated into a variety of binding molecule-linker-payload conjugates, such as ADCs, which have the potential for development as pharmaceuticals for the treatment of cancers.

[0153] Brief Description of the Figures

[0154] Figure 1 shows the potency of the payload compounds of formula 1-1 , I-2 and I-3 when tested according to Biological Example 1 in the BxPC-3 pancreatic cancer cell line;

[0155] Figure 2 shows the potency of the payload compounds of formula 1-1 , I-2 and I-3 when tested according to Biological Example 1 in the HCC1806 breast cancer cell line;

[0156] Figure 3 shows the potency of the payload compounds of formula 1-1 , I-2 and I-3 when tested according to Biological Example 1 in the OVCAR-3 ovarian cancer cell line;Figure 4 shows the potency of the payload compounds of formula 1-1 , I-2 and I-3 when tested according to Biological Example 1 in the SK-BR-3 breast cancer cell line;

[0157] Figure 5 shows the potency of the payload compounds of formula 1-1 , I-2 and I-3 when tested according to Biological Example 1 in the PA-1 ovarian cancer cell line;

[0158] Figure 6 shows the potency of the payload compounds of formula 1-1 , I-2 and I-3 when tested according to Biological Example 1 in the OV90 ovarian cancer cell line;

[0159] Figure 7 shows the potency of the Binding Molecule - Linker - Payload compounds of formula 111-1 and HI-2 when tested according to Biological Example 2 in the SK-BR-3 breast cancer cell line; and

[0160] Figure 8 shows the potency of the potency of the Binding Molecule - Linker - Payload compounds of formula HI-6, HI-7, and HI-9 when tested according to Biological Example 2 in the SK-BR-3 breast cancer cell line.

[0161] Definitions

[0162] This disclosure is not limited by the exemplary methods and materials disclosed herein, and any methods and materials similar or equivalent to those described herein can be used in the practice or testing of embodiments of this disclosure. Numeric ranges are inclusive of the numbers defining the range.

[0163] The term “polypeptide” is used in the conventional sense to mean a series of amino acids, typically L-amino acids, connected one to the other, typically by peptide bonds between the a-amino and carboxyl groups of adjacent amino acids. The term “polypeptide” is used interchangeably with the terms “amino acid sequence”, “peptide” and / or “protein”. The term “residues” is used to refer to amino acids in an amino acid sequence.

[0164] The term "variant" refers to a polypeptide that has an equivalent function to the amino acid sequences described herein, but which includes one or more amino acid substitutions, insertions or deletions.

[0165] The sequence may have one or more deletions, insertions or substitutions of amino acid residues which produce a silent change and result in a functionally equivalent molecule. These sequences are encompassed by the present invention. Deliberate amino acid substitutions may be made on the basis of similarity in polarity, charge, solubility, hydrophobicity, hydrophilicity, and / or the amphipathic nature of the residues as long as the activity is retained.

[0166] For example, negatively charged amino acids include aspartic acid and glutamic acid; positively charged amino acids include lysine and arginine; and amino acids with unchargedpolar head groups having similar hydrophilicity values include leucine, isoleucine, valine, glycine, alanine, asparagine, glutamine, serine, threonine, phenylalanine, and tyrosine.

[0167] As used herein, “variant” is synonymous with “mutant” and refers to a polynucleotide or amino acid sequence which differs in comparison to the corresponding wild-type sequence. The term “wild-type” is used to mean a gene or protein having a polynucleotide or amino acid sequence respectively, which is identical with the native gene or protein respectively. The nucleic acid sequence may be an RNA or DNA sequence or a variant thereof. The term "polynucleotide" includes an RNA or DNA sequence. It may be single or double stranded. It may, for example, be genomic, recombinant, mRNA or cDNA.

[0168] The terms “selectively binds / selectively binding” and “specifically binds / specifically binding” may be used interchangeably herein.

[0169] Where a range of values is provided, it is understood that each intervening value, to the tenth of the unit of the lower limit unless the context clearly dictates otherwise, between the upper and lower limits of that range is also specifically disclosed. Each smaller range between any stated value or intervening value in a stated range and any other stated or intervening value in that stated range is encompassed within this disclosure. The upper and lower limits of these smaller ranges may independently be included or excluded in the range, and each range where either, neither or both limits are included in the smaller ranges is also encompassed within this disclosure, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included in this disclosure.

[0170] It must be noted that as used herein and in the appended claims, the singular forms "a", "an", and "the" include plural referents unless the context clearly dictates otherwise.

[0171] The terms "comprising", "comprises" and "comprised of' as used herein are synonymous with "including", "includes" or "containing", "contains", and are inclusive or open-ended and do not exclude additional, non-recited members, elements or method steps. The terms "comprising", "comprises" and "comprised of' also include the term "consisting of'.

[0172] The terms “identity” and “% sequence identity” as used herein, may refer to the proportion of nucleotides or amino acids (expressed in percent) of a contiguous nucleotide sequence or contiguous amino acid sequence respectively which across the sequence, are identical to a reference sequence. The identity is calculated by counting the number of aligned nucleobases or amino acids that are identical (a Match) between the sequence of interest and a reference sequence, and dividing that number by the total number of nucleotidesamino acids respectively and multiplying by 100. Therefore, Percentage of Identity = (Matches x 100) / Length of aligned region. Insertions and deletions are not allowed in the calculation the percentage of identity. Chemical modifications of nucleotides may be disregarded provided that the functional capacity to form Watson-Crick base pairing is retained.

[0173] Identity comparisons can be conducted by eye, or more usually, with the aid of readily available sequence comparison programs. These commercially available computer programs can calculate % identity between two or more sequences. A suitable computer program for carrying out such an alignment is the GCG Wisconsin Bestfit package (University of Wisconsin, U.S.A.; Devereux et al., 1984, Nucleotide sequences Research 12:387). Examples of other software than can perform sequence comparisons include, but are not limited to, the BLAST package (see Ausubel et al., 1999 ibid - Chapter 18), FASTA (Atschul et al., 1990, J. Mol. Biol., 403-410) and the GENEWORKS suite of comparison tools. Both BLAST and FASTA are available for offline and online searching. For example, the percentage identity between two polypeptide sequences may be readily determined by BLAST which is freely available at http: / / blast.ncbi.nlm.nih.gov.

[0174] Once the software has produced an optimal alignment, it is possible to calculate % identity. The software typically does this as part of the sequence comparison and generates a numerical result.

[0175] The term "alkyl" refers to a monoradical of a saturated straight or branched hydrocarbon. Preferably, the alkyl group comprises from 1 to 40, i.e., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39 or 40, carbon atoms, such as 1 to 30, such as 1 to 20 carbon atoms, such as 1 to 12 carbon atoms, such as 1 to 10 carbon atoms, such as 1 to 8 carbon atoms, such as 1 to 6 or 1 to 4 carbon atoms. Exemplary alkyl groups include methyl, ethyl, propyl, iso-propyl (also called 2-propyl or 1 methylethyl), butyl, iso-butyl, tert-butyl, n-pentyl, iso-pentyl, sec-pentyl, neo-pentyl, 1,2-dimethylpropyl, iso-amyl, n-hexyl, iso-hexyl, sec-hexyl, n-heptyl, iso-heptyl, n-octyl, 2-ethyl-hexyl, n-nonyl, ndecyl, n-undecyl, n-dodecyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl, n-nonadecyl, n-icosyl, n-triacontyl, n-tetracontyl, and the like. The alkyl groups may each be substituted by one or more substituents selected from List 1, defined below.

[0176] The term "alkenyl" refers to a monoradical of an unsaturated straight or branched hydrocarbon having at least one carbon-carbon double bond. Generally, the maximal number of carbon-carbon double bonds in the alkenyl group can be equal to the integerwhich is calculated by dividing the number of carbon atoms in the alkenyl group by 2 and, if the number of carbon atoms in the alkenyl group is uneven, rounding the result of the division down to the next integer. For example, for an alkenyl group having 9 carbon atoms, the maximum number of carbon-carbon double bonds is 4. Preferably, the alkenyl group has 1 to 6 (such as 1 to 4), i.e., 1, 2, 3, 4, 5, or 6, carbon-carbon double bonds. Preferably, the alkenyl group comprises from 2 to 40 carbon atoms, such as 2 to 30 carbon atoms, such as 2 to 20 carbon atoms, such as 2 to 12 carbon atoms, such as 2 to 10 carbon atoms, such as 2 to 8 carbon atoms, such as 2 to 6 carbon atoms or 2 to 4 carbon atoms. Thus, in a preferred embodiment, the alkenyl group comprises from 2 to 40, such as 2 to 30, such as 2 to 20, such as 2 to 12, such as 2 to 10 carbon atoms and 1, 2, 3, 4, 5, or 6 (e.g., 1, 2, 3, 4, or 5) carbon-carbon double bonds, such as comprises 2 to 8 carbon atoms and 1, 2, 3, or 4 carbon-carbon double bonds, such as 2 to 6 carbon atoms and 1, 2, or 3 carbon-carbon double bonds or 2 to 4 carbon atoms and 1 or 2 carbon-carbon double bonds. The carboncarbon double bond(s) may be in cis (Z) or trans (E) configuration. Exemplary alkenyl groups include vinyl, 1-propenyl, 2-propenyl (i.e., allyl), 1-butenyl, 2-butenyl, 3-butenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 4-pentenyl, 1 -hexenyl, 2-hexenyl, 3-hexenyl, 4-hexenyl, 5-hexenyl, 1-heptenyl, 2-heptenyl, 3-heptenyl, 4-heptenyl, 5-heptenyl, 6-heptenyl, 1 -octenyl, 2-octenyl, 3-octenyl, 4-octenyl, 5-octenyl, 6-octenyl, 7-octenyl, 1-nonenyl, 2-nonenyl, 3-nonenyl, 4-nonenyl, 5-nonenyl, 6-nonenyl, 7-nonenyl, 8-nonenyl, 1 -decenyl, 2-decenyl, 3-decenyl, 4-decenyl, 5-decenyl, 6-decenyl, 7-decenyl, 8-decenyl, 9-decenyl, 1 -undecenyl, 2-undecenyl, 3-undecenyl, 4-undecenyl, 55-undecenyl, 6-undecenyl, 7-undecenyl, 8-undecenyl, 9-undecenyl, 10-undecenyl, 1 -dodecenyl, 2-dodecenyl, 3-dodecenyl, 4-dodecenyl, 5-dodecenyl, 6-dodecenyl, 7-dodecenyl, 8-dodecenyl, 9-dodecenyl, 10-dodecenyl, 11-dodecenyl, and the like. The alkenyl groups may each be substituted by one or more substituents selected from List 1, defined below.

[0177] The term "alkynyl" refers to a monoradical of an unsaturated straight or branched hydrocarbon having at least one carbon-carbon triple bond. Preferably, the alkynyl group has 1 to 6 (such as 1 to 4), i.e., 1, 2, 3, 4, 5, or 6, carbon-carbon triple bonds. Preferably, the alkynyl group comprises from 2 to 40 carbon atoms, such as 2 to 30 carbon atoms, such as 2 to 20 carbon atoms, such as 2 to 12 carbon atoms, such as 2 to 10 carbon atoms, such as 2 to 8 carbon atoms, such as 2 to 6 carbon atoms or 2 to 4 carbon atoms. Thus, in a preferred embodiment, the alkynyl group comprises from 2 to 40, such as 2 to 30, such as 2 to 20, such as 2 to 12, such as 2 to 10 carbon atoms and 1, 2, 3, 4, 5, or 6 (e.g., 1, 2, 3, 4, or 5) carbon-carbon triple bonds, such as comprises 2 to 8 carbon atoms and 1 , 2, 3, or 4 carbon-carbon triple bonds, such as 2 to 6 carbon atoms and 1, 2, or 3 carbon-carbon triple bonds or 2 to 4 carbon atoms and 1 or 2 carbon-carbon triple bonds. Exemplary alkynylgroups include ethynyl, 1-propynyl, 2-propynyl 1 -butynyl, 2-butynyl, 3-butynyl, 1 -pentynyl, 2-pentynyl, 3-pentynyl, 4-pentynyl, 1 -hexynyl, 2-hexynyl, 3-hexynyl, 4-hexynyl, 5-hexynyl, 1-heptynyl, 2-heptynyl, 3-heptynyl, 4-heptynyl, 5-heptynyl, 6-heptynyl, 1 -octynyl, 2-octynyl, 3-octynyl, 4-octynyl, 5-octynyl, 6-octynyl, 7-octynyl, 1-nonynyl, 2-nonynyl, 3-nonynyl, 4-nonynyl, 5-nonynyl, 6-nonynyl, 7-nonynyl, 8-nonynyl, 1 -decynyl, 2-decynyl, 3-decynyl, 4-decynyl, 5-decynyl, 6-decynyl, 7-decynyl, 8-decynyl, 9-decynyl, 1 -undecynyl, 2-undecynyl, 3-undecynyl, 4-undecynyl, 55-undecynyl, 6-undecynyl, 7-undecynyl, 8-undecynyl, 9-undecynyl, 10-undecynyl, 1 -dodecynyl, 2-dodecynyl, 3-dodecynyl, 4-dodecynyl, 5-dodecynyl, 6-dodecynyl, 7-dodecynyl, 8-dodecynyl, 9-dodecynyl, 10-dodecynyl, 11-dodecynyl, and the like. The alkynyl groups may each be substituted by one or more substituents selected from List 1, defined below.

[0178] The terms "cycloalkyl" and “cycloalkenyl” represents cyclic non-aromatic versions of "alkyl" and "alkenyl" with preferably 3 to 40, such as 3 to 30, such as 3 to 20, such as 3 to 14 carbon atoms, such as 3 to 12 or 3 to 10 carbon atoms, i.e., 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, or 14 carbon atoms (such as 3, 4, 5, 6, 7, 8, 9, or 10 carbon atoms), more preferably 3 to 7 carbon atoms. Exemplary cycloalkyl groups include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, and adamantyl. Exemplary cycloalkenyl groups include cyclopropenyl, cyclobutenyl, cyclopentenyl, cyclohexenyl, cycloheptenyl, cyclooctenyl, cyclononenyl, and cyclodecenyl. The cycloalkyl or cycloalkenyl group may consist of one ring (monocyclic), two rings (bicyclic), or more than two rings (polycyclic). The cycloalkyl groups may each be substituted by one or more substituents selected from List 1 , defined below.

[0179] The term "aryl" refers to a monoradical of an aromatic cyclic hydrocarbon. Preferably, the aryl group contains 3 to 14 (e.g., 5, 6, 7, 8, 9, or 10, such as 5, 6, or 10) carbon atoms which can be arranged in one ring (e.g., phenyl) or two or more condensed rings (e.g., naphthyl). Exemplary aryl groups include cyclopropenylium, cyclopentadienyl, phenyl, indenyl, naphthyl, azulenyl, fluorenyl, anthryl, and phenanthryl. Preferably, "aryl" refers to a monocyclic ring containing 6 carbon atoms or an aromatic bicyclic ring system containing 10 carbon atoms. Preferred examples are phenyl and naphthyl. The aryl groups may each be substituted by one or more substituents selected from List 1 , defined below.

[0180] The term "heteroaryl" or "heteroaromatic ring" means an aryl group as defined above in which one or more carbon atoms in the aryl group are replaced by heteroatoms of O, S, or N. Preferably, heteroaryl refers to a five or six-membered aromatic monocyclic ring wherein 1 , 2, or 3 carbon atoms are replaced by the same or different heteroatoms of O, N, or S. Alternatively, it means an aromatic bicyclic or tricyclic ring system wherein 1, 2, 3, 4, or 5carbon atoms are replaced with the same or different heteroatoms of O, N, or S. Preferably, in each ring of the heteroaryl group the maximum number of O atoms is 1, the maximum number of S atoms is 1 , and the maximum total number of O and S atoms is 2. Exemplary heteroaryl groups include furanyl, thienyl, oxazolyl, isoxazolyl, oxadiazolyl, pyrrolyl, imidazolyl, pyrazolyl, triazolyl, tetrazolyl, thiazolyl, isothiazolyl, thiadiazolyl, pyridyl, pyrimidinyl, pyrazinyl, triazinyl, benzofuranyl, indolyl, isoindolyl, benzothienyl, 1H-indazolyl, benzimidazolyl, benzoxazolyl, indoxazinyl, benzisoxazolyl, benzothiazolyl, benzisothiazolyl, benzotriazolyl, quinolinyl, isoquinolinyl, benzodiazinyl, quinoxalinyl, quinazolinyl, benzotriazinyl, pyridazinyl, phenoxazinyl, thiazolopyridinyl, pyrrolothiazolyl, phenothiazinyl, isobenzofuranyl, chromenyl, xanthenyl, pyrrolizinyl, indolizinyl, indazolyl, purinyl, quinolizinyl, phthalazinyl, naphthyridinyl, cinnolinyl, pteridinyl, carbazolyl, phenanthridinyl, acridinyl, perimidinyl, phenanthrolinyl, and phenazinyl. Exemplary 5- or6-memered heteroaryl groups include furanyl, thienyl, oxazolyl, isoxazolyl, oxadiazolyl, pyrrolyl, imidazolyl (e.g., 2-imidazolyl), pyrazolyl, triazolyl, tetrazolyl, thiazolyl, isothiazolyl, thiadiazolyl, pyridyl (e.g., 4-pyridyl), pyrimidinyl, pyrazinyl, triazinyl, and pyridazinyl. The heteroaryl groups may each be substituted by one or more substituents selected from List 1 , defined below.

[0181] The term "heterocyclyl" means a cycloalkyl group as defined above in which from 1, 2, 3, or 4 carbon atoms in the cycloalkyl group are replaced by heteroatoms selected from O, S, and N. A heterocyclyl group has preferably 1 or 2 rings containing from 3 to 10, such as 3, 4, 5, 6, or 7, ring atoms. Preferably, in each ring of the heterocyclyl group the maximum number of O atoms is 1 , the 5 maximum number of S atoms is 1 , and the maximum total number of O and S atoms is 2. The term "heterocyclyl" is also meant to encompass partially or completely hydrogenated forms (such as dihydro, tetrahydro or perhydro forms) of the above-mentioned heteroaryl groups. Exemplary heterocyclyl groups include morpholinyl, pyrrolidinyl, imidazolidinyl, pyrazolidinyl, piperidinyl (also called piperidyl), piperazinyl, di- and tetrahydrofuranyl, di- and tetrahydrothienyl, di- and tetrahydropyranyl, urotropinyl, lactones, lactams, cyclic imides, and cyclic anhydrides. The heterocyclyl groups may each be substituted by one or more substituents selected from List 1 , defined below.

[0182] The term "alkylene" refers to a diradical of a saturated straight or branched hydrocarbon. Preferably, the alkylene group comprises from 1 to 40, / .e., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39 or 40, carbon atoms, such as 1 to 30, such as 1 to 20 carbon atoms, such as 1 to 12 carbon atoms, such as 1 to 10 carbon atoms, such as 1 to 8 carbon atoms, such as 1 to 6 or 1 to 4 carbon atoms. Exemplary alkylene groups include methylene, ethylene ( / .e., 1,1-ethylene, 1,2-ethylene), propylene ( / .e., 1,1 -propylene, 1,2-propylene (-CH(CH3)CH2-), 2,2-propylene (-C(CH3)2-), and 1,3-propylene), the butylene isomers (e.g., 1,1 -butylene, 1,2-butylene, 2,2-butylene, 1 ,3-butylene, 2,3-butylene (cis or trans or a mixture thereof), 1 ,4-butylene, 1,1 -iso-butylene, 1,2-iso-butylene, and 1,3-iso-butylene), the pentylene isomers e.g., 1,1 -pentylene, 1,2-pentylene, 1,3-pentylene, 1,4-pentylene, 1,5-pentylene, 1,1-iso-pentylene, 1,1 -sec-pentyl, 1,1-neo-pentyl), the hexylene isomers (e.g., 1,1 -hexylene, 1,2-hexylene, 1,3-hexylene, 1 ,4-hexylene, 1,5-hexylene, 1 ,6-hexylene, and 1,1 -isohexylene), the heptylene isomers (e.g., 1,1 -heptylene, 1,2-heptylene, 1,3-heptylene, 1,4-heptylene, 1,5-heptylene, 1,6-heptylene, 1,7-heptylene, and 1,1 -isoheptylene), the octylene isomers (e.g., 1,1 -octylene, 1,2-octylene, 1,3-octylene, 1 ,4-octylene, 1,5-octylene, 1,6-octylene, 1,7-octylene, 1,8-octylene, and 1,1 -isooctylene), and the like. The straight alkylene moieties having at least 3 carbon atoms and a free valence at each end can also be designated as a multiple of methylene (e.g., 1,4-butylene can also be called tetramethylene). Generally, instead of using the ending "ylene" for alkylene moieties as specified above, one can also use the ending "diyl" (e.g., 1,2-butylene can also be called butan-1,2-diyl). The alkylene groups may be substituted with one or more, preferably 1 to 5, such as 1, 2, or 3 substituents selected from List 1.

[0183] The terms "alkenylene" and “alkynylene” refers to a diradical of a straight or branched hydrocarbon containing at least one carbon-carbon double or triple bond respectively.

[0184] Preferably, the alkenylene or alkynylene group comprises from 2 to 40, i.e., 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39 or 40, carbon atoms, such as 2 to 30, such as 2 to 20 carbon atoms, such as 2 to 12 carbon atoms, such as 2 to 10 carbon atoms, such as 2 to 8 carbon atoms, such as 2 to 6 or 2 to 4 carbon atoms. Exemplary alkenylene groups include vinylene, propenylene and the butenylenes. Exemplary alkynylene groups include ethynylene, propynylene and the butynylenes. The alkenylene or alkynylene groups may be substituted with one or more, preferably 1 to 5, such as 1, 2, or 3 substituents selected from List 1.

[0185] The term "cycloalkylene", “cycloalkenylene” and “cycloalkynylene” represent cyclic nonaromatic versions of "alkylene", “alkenylene” and “alkynylene” with preferably 3 to 40, such as 3 to 30, such as 3 to 20, such as 3 to 14 carbon atoms, such as 3 to 12 or 3 to 10 carbon atoms, i.e., 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, or 14 carbon atoms (such as 3, 4, 5, 6, 7, 8, 9, or 10 carbon atoms). More preferably cycloalkylene and cycloalkenylene have 3 to 10, especially 3 to 7, carbon atoms and cycloalkynylene have 8 to 10 carbon atoms. Exemplary cycloalkylene groups include cyclopropylene, cyclobutylene, cyclopentylene, cyclohexylene, cycloheptylene, cyclooctylene, cyclononylene, and cyclodecylene. Exemplary cycloalkenylene groups include cyclopropenylene, cyclobutenylene, cyclopentenylene,cyclohexenylene, cycloheptenylene, cyclooctenylene, cyclononenylene, and cyclodecenylene. Exemplary cycloalkynylene groups include cyclooctynylene, cyclononynylene, and cyclodecynylene. The cycloalkylene, cycloalkenylene or cycloalkynylene group may consist of one ring (monocyclic), two rings (bicyclic), or more than two rings (polycyclic). The cycloalkylene, cycloalkenylene or cycloalkynylene groups may be substituted with one or more, preferably 1 to 5, such as 1 , 2, or 3 substituents selected from List 1.

[0186] The term "heterocycloalkylene", “heterocycloalkenylene” and “heterocycloalkynylene” represent non-aromatic heterocyclic versions of "cycloalkylene", “cycloalkenylene” and “cycloalkynylene” with 3 to 14 ring atoms, or 3 to 10 ring atoms, i.e., 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, or 14 ring atoms (such as 3, 4, 5, 6, 7, 8, 9, or 10 ring atoms), wherein 1 to 5, such as 1 to 4, such as 1 , 2 or 3, such as 1 or 2, ring atoms are heteroatoms selected from N, O and S, and the other ring atoms are carbon atoms. More preferably heterocycloalkylene and heterocycloalkenylene have 3 to 10, especially 3 to 7, ring atoms and heterocycloalkynylene has 8 to 10 ring atoms, wherein 1, 2 or 3, such as 1 or 2, ring atoms are heteroatoms selected from N, O and S, and the other ring atoms are carbon atoms. The heterocycloalkylene, heterocycloalkenylene or heterocycloalkynylene group may consist of one ring (monocyclic), two rings (bicyclic), or more than two rings (polycyclic). Examples of heterocycloalkylene groups include aziridylene, oxiranylene, thiiranylene, azetidinylene, oxetanylene, thietanylene, pyrrolidinylene, tetrahydrofuranylene, tetrhydrothiophenylene, pyrazolidinylene, imidazolinylene, dioxolanylene, thiazolidinylene, isoxazolidinylene, piperidinylene, piperazinylene, morpholinylene, 1,4-dioxanylene, thiomorpholinylene, 1,4-oxathianylene, 1,4-dithianylene, 1,3,5-trioxanylene, 1,3,5-thithianylene, azepanylene, oxepanylene, thiepanylene, diazepanylene, oxazapenylene, thiazepanylene, azocanylene, oxocanylene, thiocanylene, azonanylene, oxonanylene and thionanylene. Examples of heterocycloalkenylene groups include 1-, 2- or 3-pyrrolinylene, 2-or 3-pyrazolinylene, imidazolinylene, 2H or 4H-pyranylene, 3,4-dihydropyranylene, 1,4-thiazinylene, 1 ,4-oxazinylene, azepinylene, oxepinylene, thiepinylene, diazepinylene, oxazepinylene, thiazepinylene, azocinylene, oxocinylene, thiocinylene, azoninylene, oxoninylene and thioninylene. The heterocycloalkylene, heterocycloalkenylene or heterocycloalkynylene groups may be substituted with one or more, preferably 1 to 5, such as 1, 2, or 3 substituents selected from List 1.

[0187] “Halogen” means fluorine, chlorine, bromine or iodine.Substituents

[0188] In the compounds of the present invention, the substituents may have the meanings defined herein. The general definitions of the substituents are equally applicable to the payload compounds of formula (I), including those compounds of formulae (l-Y), (l-A), (l-B), (l-C), (I-D), the payload-linker compounds of formula (II), including those compounds of formulae (II-Y), (ll-YY), (I l-A), (I l-B), (ll-C), (I l-D), and the binding molecule- linker payload compounds (such as antibody-drug conjugates) of formula (III), including those compounds of formula (III’), (Hl-Y), (lll-YY), (lll-A), (lll-B), (lll-C), (lll-D), present in the compositions of the present invention as described herein, as appropriate.

[0189] U

[0190] II is O or S. In one embodiment, II is O. In one embodiment, II is S.

[0191] X

[0192] X is a bond, O, S, S(=O) or S(=O)2.

[0193] In one embodiment, X is O, S, S(=O) or S(=O)2.

[0194] In one embodiment, X is O, S or a bond.

[0195] In one embodiment, X is S, S(=O) or S(=O)2 or a bond.

[0196] In one embodiment, X is O. In one embodiment, X is a bond. In one embodiment, X is S. In one embodiment, X is S(=O). In one embodiment, X is S(=O)2.

[0197] A

[0198] When X is O, S, S(=O) or S(=O)2, A is C2-10 alkylene, C2-10 alkenylene, C2- alkynylene, C3-10 cycloalkylene, C3-10 cycloalkenylene, Cs- cycloalkynylene, C3-10 heterocycloalkylene, C3-10 heterocycloalkenylene, or Cs- heterocycloalkynylene.

[0199] In some embodiments, when X is O, S, S(=O) orS(=O)2, A is C4-10 alkylene, C2-10 alkenylene, C2- alkynylene, C3-10 cycloalkylene, C3-10 cycloalkenylene, Cs- cycloalkynylene, C3-10 heterocycloalkylene, C3-10 heterocycloalkenylene, or Cs- heterocycloalkynylene.When X is a bond, A is C1-10 alkylene, C2-10 alkenylene, C2- alkynylene, C3-10 cycloalkylene, C3-10 cycloalkenylene, or Cs- cycloalkynylene, C3-10 heterocycloalkylene, C3-10 heterocycloalkenylene, or Cs- heterocycloalkynylene.

[0200] In some embodiments, when X is a bond, A is C2-10 alkylene, C2-10 alkenylene, C2-10 alkynylene, C3-10 cycloalkylene, C3-10 cycloalkenylene, or Cs- cycloalkynylene, C3-10 heterocycloalkylene, C3-10 heterocycloalkenylene, or Cs- heterocycloalkynylene.

[0201] In one embodiment, when X is O and R1 is ethyl, A is not C2-3 alkylene.

[0202] In one embodiment, A is C2-10 alkylene, C2-10 alkenylene, C2-10 alkynylene, C3-10 cycloalkylene, C3-10 cycloalkenylene, Cs- cycloalkynylene. In one embodiment, A is C2-10 alkylene, C2-10 alkenylene, C2-10 alkynylene, C3-10 cycloalkylene, or C3-10 cycloalkenylene. In one embodiment, A is C2-10 alkylene, C2-10 alkenylene, C3-10 cycloalkylene, or Cs-cycloalkenylene. In one embodiment, A is C2-10 alkylene or C3-10 cycloalkylene. In one embodiment, A is C2-10 alkylene. In one embodiment, A is C2-10 alkenylene. In one embodiment, A is C2-10 alkynylene. In one embodiment, A is C3-10 cycloalkylene. In one embodiment, A is C3-10 cycloalkenylene. In one embodiment, A is Cs- cycloalkynylene.

[0203] In one embodiment, A is C1-10 alkylene, C2-10 alkenylene, C2-10 alkynylene, C3-10 cycloalkylene, C3-10 cycloalkenylene, Cs- cycloalkynylene. In one embodiment, A is C1-10 alkylene, C2-10 alkenylene, C2-10 alkynylene, C3-10 cycloalkylene, or C3-10 cycloalkenylene. In one embodiment, A is C1-10 alkylene, C2-10 alkenylene, C3-10 cycloalkylene, or Cs-cycloalkenylene. In one embodiment, A is C1-10 alkylene or C3-10 cycloalkylene. In one embodiment, A is C1-10 alkylene.

[0204] In one embodiment, A is C1-10 alkylene. In one embodiment, A is C4-10 alkylene. In one embodiment, A is C4-8 alkylene. In one embodiment, A is C4-6 alkylene. In one embodiment, A is C2-10 alkylene. In one embodiment, A is C1-9 alkylene. In one embodiment, A is C2-9 alkylene. In one embodiment, A is C1-8 alkylene. In one embodiment, A is C2-8 alkylene. In one embodiment, A is C1-7 alkylene. In one embodiment, A is C2-7 alkylene. In one embodiment, A is C1-6 alkylene. In one embodiment, A is C2-6 alkylene. In one embodiment, A is C1-5 alkylene. In one embodiment, A is C2-5 alkylene. In one embodiment, A is C1-4 alkylene. In one embodiment, A is C2-4 alkylene. In one embodiment, A is C1-3 alkylene. In one embodiment, A is C2-3 alkylene. In one embodiment, A is C1-2 alkylene. In one embodiment, A is methylene. In one embodiment, A is ethylene. In one embodiment, A is 1,1-ethylene. Inone embodiment, A is 1,2-ethylene. In one embodiment, A is propylene. In one embodiment, A is 1,1 -propylene. In one embodiment, A is 1,2-propylene. In one embodiment, A is 1,3-propylene. In one embodiment, A is butylene. In one embodiment, A is 1,1-butylene. In one embodiment, A is 1,2-butylene. In one embodiment, A is 1,3-butylene. In one embodiment, A is 1,4-butylene. In one embodiment, A is pentylene. In one embodiment, A is 1,1 -pentylene. In one embodiment, A is 1,2-pentylene. In one embodiment, A is 1,3-pentylene. In one embodiment, A is 1,4-pentylene. In one embodiment, A is 1,5-pentylene. In one embodiment, A is hexylene. In one embodiment, A is 1,1-hexylene. In one embodiment, A is 1 ,2-hexylene. In one embodiment, A is 1,3-hexylene. In one embodiment, A is 1 ,4-hexylene. In one embodiment, A is 1,5-hexylene. In one embodiment, A is 1 ,6-hexylene. In one embodiment, A is unsubstituted C1-10 alkylene. In one embodiment, A is unsubstituted C2-10 alkylene. In one embodiment, A is unsubstituted C2-6 alkylene. In one embodiment, A is unsubstituted C2-4 alkylene.

[0205] In one embodiment, A is unsubstituted C4-10 alkylene. In one embodiment, A is unsubstituted C4-8 alkylene. In one embodiment, A is unsubstituted C4-6 alkylene.

[0206] In one embodiment, A is C3-10 cycloalkylene. In one embodiment, A is C3-9 cycloalkylene. In one embodiment, A is C3-8 cycloalkylene. In one embodiment, A is C3-7 cycloalkylene. In one embodiment, A is C3-6 cycloalkylene. In one embodiment, A is cyclopropylene. In one embodiment, A is 1,1 -cyclopropylene. In one embodiment, A is 1 ,2-cyclopropylene. In one embodiment, A is cyclobutylene. In one embodiment, A is 1,1 -cyclobutylene. In one embodiment, A is 1 ,2-cyclobutylene. In one embodiment, A is 1,3-cyclobutylene. In one embodiment, A is cyclopentylene. In one embodiment, A is 1,1 -cyclopentylene. In one embodiment, A is 1 ,2-cyclopentylene. In one embodiment, A is 1 ,3-cyclopentylene. In one embodiment, A is cyclohexylene. In one embodiment, A is 1,1 -cyclohexylene. In one embodiment, A is 1 ,2-cyclohexylene. In one embodiment, A is 1,3-cyclohexylene. In one embodiment, A is 1 ,4-cyclohexylene.

[0207] The alkylene, alkenylene, alkynylene, cycloalkylene, cycloalkenylene, cycloalkynylene, heterocycloalkylene, heterocycloalkenylene, or heterocycloalkynylene groups may each be substituted by one or more substituents selected from List 1 , defined below. In one embodiment, the alkylene, alkenylene, alkynylene, cycloalkylene, cycloalkenylene, cycloalkynylene, heterocycloalkylene, heterocycloalkenylene, or heterocycloalkynylene groups may each be substituted by one or more substituents selected from List 1A, defined below. In one embodiment, the alkylene, alkenylene, alkynylene, cycloalkylene, cycloalkenylene, cycloalkynylene, heterocycloalkylene, heterocycloalkenylene, or heterocycloalkynylene groups may each be substituted by one or more substituents selectedfrom List 1 B, defined below. In one embodiment, the alkylene, alkenylene, alkynylene, cycloalkylene, cycloalkenylene, cycloalkynylene, heterocycloalkylene, heterocycloalkenylene, or heterocycloalkynylene groups may each be substituted by one or more substituents selected from List 1 C, defined below. In one embodiment, the alkylene, alkenylene, alkynylene, cycloalkylene, cycloalkenylene, cycloalkynylene, heterocycloalkylene, heterocycloalkenylene, or heterocycloalkynylene groups may each be substituted by one or more substituents selected from List 1 D, defined below.

[0208] In some embodiments, the alkylene, alkenylene, alkynylene, cycloalkylene, cycloalkenylene, cycloalkynylene, heterocycloalkylene, heterocycloalkenylene, or heterocycloalkynylene groups are unsubstituted.

[0209] Ri

[0210] In one embodiment, Ri is H, C1-6 alkyl or C3-6 cycloalkyl. In one embodiment, Ri and R4 together with the carbon atoms to which they are attached form a 5- to 7-membered carbocyclic ring which is substituted by a group -NH-C(=O)-Rs. In the latter embodiment, the compounds of formulae (I), (II) and (III) comprise compounds of formula (IA), (IIA), and (111 A) as described in more detail below.

[0211] In one embodiment, Ri is H or C1-6 alkyl. In one embodiment, Ri is H or C1-5 alkyl. In one embodiment, Ri is H or C1-4 alkyl. In one embodiment, Ri is H or C1-3 alkyl. In one embodiment, Ri is H, methyl or ethyl. In one embodiment, Ri is H. In one embodiment, Ri is C1-6 alkyl. In one embodiment, Ri is C1-5 alkyl. In one embodiment, Ri is C1-4 alkyl. In one embodiment, Ri is C1-3 alkyl. In one embodiment, Ri is C2-6-alkyl. In one embodiment, Ri is C2-5 alkyl. In one embodiment, Ri is C2-4 alkyl. In one embodiment, Ri is methyl or ethyl. In one embodiment, Ri is methyl. In one embodiment, Ri is ethyl.

[0212] In one embodiment, Ri is Cs-e-cycloalkyl. In one embodiment, Ri is Cs-s-cycloalkyl. In one embodiment, Ri is C3-4-cycloalkyl. In one embodiment, Ri is cyclopropyl. In one embodiment, Ri is Me, Et or Cs-e-cycloalkyl. In one embodiment, Ri is Me or Cs-e-cycloalkyl. In one embodiment, Ri is Et or Cs-e-cycloalkyl.

[0213] In one embodiment, either: Ri is H, C1-6 alkyl, or C3-6 cycloalkyl, and R4 is H or C1-6 alkyl, or: Ri and R4 together with the carbon atoms to which they are attached form a 5- to 7-membered carbocyclic ring which is substituted by a group -NH-C(=O)-Rs.R2

[0214] R2 is H, halogen, or C1-6 alkyl. In one embodiment, R2 is H, halogen or C1-4 alkyl. In one embodiment, R2 is H, halogen or C1-3 alkyl.

[0215] In one embodiment, R2 is halogen or C1-6 alkyl. In one embodiment, R2 is halogen or C1-3 alkyl In one embodiment, R2 is halogen or C1-2 alkyl.

[0216] In one embodiment, R2 is H.

[0217] In one embodiment, R2 is halogen. In one embodiment, R2 is F. In one embodiment, R2 is Cl. In one embodiment, R2 is Br. In one embodiment, R2 is I.

[0218] In one embodiment, R2 is C1-6 alkyl. In one embodiment, R2 is C1-5 alkyl. In one embodiment, R2 is C1-4 alkyl. In one embodiment, R2 is C1-3 alkyl. In one embodiment, R2 is methyl or ethyl. In one embodiment, R2is methyl. In one embodiment, R2 is ethyl.

[0219] R3

[0220] R3 is C1-6 alkyl. In one embodiment, R3 is C1-4 alkyl. In one embodiment, R3 is C1-3 alkyl.

[0221] In one embodiment, Rsis methyl. In one embodiment, R3 is ethyl.

[0222] R4

[0223] In one embodiment, R4 is H or C1-6 alkyl. In another embodiment, R1 and R4 together with the carbon atoms to which they are attached form a 5- to 7-membered carbocyclic ring which is substituted by a group -NH-C(=O)-Rs. In the latter embodiment, the compounds of formulae (I), (II) and (III) comprise compounds of formulae (IA), (IIA) and (IIIA) as described in more detail below. In another embodiment, R1 and R4 together with the carbon atoms to which they are attached form a 6-membered carbocyclic ring which is substituted by a group -NH-C(=O)-Rs. In another embodiment, R1 and R4 together with the carbon atoms to which they are attached form a 6-membered carbocyclic ring which is substituted by a group -NH-C(=O)-Me.

[0224] In one embodiment, R4 is H. In one embodiment, R4 is C1-4 alkyl. In one embodiment, R4 is C1-3 alkyl. In one embodiment, R4 is methyl. In one embodiment, R4 is ethyl.Rs

[0225] Rs is C1-6 alkyl. In one embodiment, Rs is C1-4 alkyl. In one embodiment, R5 is C1-3 alkyl.

[0226] In one embodiment, Rs is methyl. In one embodiment, Rs is ethyl.

[0227] Y

[0228] Y is a group capable of conjugating with a binding molecule to generate a conjugate. The precise nature of Y is not limited provided that it is capable of performing this function. In one embodiment, the conjugation takes place by displacement of all of part of the group Y by a suitable moiety (typically a thiol group) on the binding moiety. In one embodiment, the conjugation takes place by addition to the group Y by a suitable moiety (typically a thiol group) on the binding moiety.

[0229] In one embodiment, Y comprises a sulfone moiety. In one embodiment, Y comprises a (C1-6 alkyl)sulfonyl moiety. In one embodiment, Y comprises a (C1-4 alkyl)sulfonyl moiety. In one embodiment, Y comprises a (C1-3 alkyl)sulfonyl moiety. In one embodiment, Y comprises a methylsulfonyl or ethylsulfonyl moiety. In one embodiment, Y comprises a methylsulfonyl moiety. In one embodiment, Y comprises an ethylsulfonyl moiety.

[0230] In one embodiment, Y comprises a pyrimidine-sulfone moiety.

[0231] In one embodiment, Y comprises an unsaturated imide moiety. In one embodiment, Y comprises a 5- to 7-membered cyclic unsaturated imide moiety. In one embodiment, Y comprises a maleimide moiety.

[0232] Re and R7

[0233] In one embodiment, Re is H or C1-6 alkyl. In one embodiment, Re is H or C1-4 alkyl. In one embodiment, Re is H or C1-3 alkyl. In one embodiment, Re is H, methyl or ethyl. In one embodiment, Re is H.

[0234] In one embodiment, R7 is H or C1-6 alkyl. In one embodiment, R7 is H or C1-4 alkyl. In one embodiment, R7 is H or C1-3 alkyl. In one embodiment, R7 is H, methyl or ethyl. In one embodiment, R7 is H.In one embodiment, Re and R? together with the carbon atom to which they are attached form a 3- to 10-membered carbocyclic ring. In one embodiment, Re and R? together with the carbon atom to which they are attached form a 3- to 8-membered carbocyclic ring. In one embodiment, Re and R? together with the carbon atom to which they are attached form a 3-to 6-membered carbocyclic ring.

[0235] In one embodiment, Re and R? are each H.

[0236] R’ and R”

[0237] In one embodiment, Rs is NR’R”. In one embodiment, R’ is H or C1-6 alkyl. In one embodiment, R’ is H or C1-4 alkyl. In one embodiment, R’ is H or C1-3 alkyl. In one embodiment, R’ is H, methyl or ethyl. In one embodiment, R’ is H.

[0238] In one embodiment, R” is H or C1-6 alkyl. In one embodiment, R” is H or C1-4 alkyl. In one embodiment, R” is H or C1-3 alkyl. In one embodiment, R” is H, methyl or ethyl. In one embodiment, R” is H.

[0239] n and m

[0240] n is 0, 1 , or 2. m is 0, 1 or 2. m+n must be 1 , 2 or 3.

[0241] In one embodiment, n is 0. In one embodiment, n is 1. In one embodiment, n is 2.

[0242] In one embodiment, m is 0. In one embodiment, m is 1. In one embodiment, m is 2.

[0243] vand w

[0244] v is O or 1 to 40, such as 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39 or 40. In some embodiments, v is 0 or 1 to 30. In some embodiments, v is 0 or 1 to 20. In some embodiments, v is 0 or 1 to 10. In some embodiments, v is 0 or 1 to 8. In some embodiments, v is 0 or 1 to 7. In some embodiments, v is 0 or 1 to 6. In some embodiments, v is 0 or 1 to 5. In some embodiments, v is 0 or 1 to 4. In some embodiments, v is 0 or 1 to 3. In some embodiments, v is 2 to 10. In some embodiments, v is 2 to 8. In some embodiments, v is 2 to 7. In some embodiments, v is 2 to 6. In some embodiments, v is 2 to 5. In some embodiments, v is 2 to 4. In some embodiments, v is 2. In some embodiments, v is 0.w is 0 or 1 to 10, such as 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10. In some embodiments, w is 0 or 1 to 8. In some embodiments, w is 0 or 1 to 6. In some embodiments, w is 0 or 1 to 5. In some embodiments, w is 0 or 1 to 4. n some embodiments, w is 1 to 3. In some embodiments, w is 0, 1 or 2. In some embodiments, w is 0 or 1. In some embodiments, w is 0. In some embodiments, w is 1.

[0245] Lists 1A, 1B, 1C and 1D

[0246] “List 1” substituents are selected from the group consisting of C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, 6- to 14-membered (such as 6- to 10-membered) aryl, 3- to 14-membered (such as 5- or 6- membered) heteroaryl, 3- to 14-membered (such as 3- to 7-membered) cycloalkyl, 3-to 14-membered (such as 3- to 7-membered) heterocyclyl, halogen, -CN, azido, -NO2, -OR’, -N(R’)2, -S(0)O-2R’, -S(O)I-2OR’, -OS(O)I.2R’, -OS(O)I-2OR’, -S(O)I-2N(R’)2, -OS(O)I-2N(R’)2, -N(R’)S(O)I-2R’, -N(R’)S(O)I-2OR’, -C(=X1)R’, -C(=X1)X1R’, -X1C(=X1)R’, and -X1C(=X1)X1R’, wherein X1is independently selected from O, S, NH and N(CHs); and each R’ is independently selected from the group consisting of H, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, 5-or 6-membered cycloalkyl, 5- or 6-membered aryl, 5- or 6-membered heteroaryl, and 5- ore-membered heterocyclyl, wherein each of the alkyl, alkenyl, alkynyl, cycloalkyl, aryl, heteroaryl, and heterocyclyl groups is optionally substituted with one, two or three substituents independently selected from the group consisting of C1-3 alkyl, halogen, -CF3, -CHF2, CH2F, -CN, azido, -NO2, -OH, -O(Ci-3alkyl), -S(Ci-3alkyl), -NH2, -NH(CI-3alkyl), -N(Ci- 3 alkyl)2, -NHS(O)2(CI-3alkyl), -S(O)2NH2-Z(CI-3alkyl)z, -C(=O)OH, -C(=O)O(C1.3alkyl), -C(=O)NH2-z(Ci-3alkyl)z, -NHC(=O)(C1-3 alkyl), -NHC(=NH)NHz.2(C1-3 alkyl)z, and -N(CI-3alkyl)C(=NH)NH2-z(Ci-3alkyl)z, wherein each z is independently 0, 1, or 2.

[0247] In some embodiment, the substituents are selected from List 1A, consisting of C1-3 alkyl, phenyl, halogen, -CF3, - CHF2, CH2F, -OH, -OCH3, -SCH3, -NH2-Z(CH3)Z, -C(=O)OH, and -C(=O)OCH3, wherein z is 0, 1, or 2 and C1-3 alkyl is methyl, ethyl, propyl or isopropyl.

[0248] In some embodiments, the substituents are selected from List 1B, consisting of methyl, ethyl, propyl, isopropyl, halogen (such as F, Cl, or Br), -CF3 -CHF2, and -CH2F.

[0249] In some embodiments, the substituents are selected from List 1 C, consisting of halogen (such as F, Cl, or Br). In some embodiments, the substituents are selected from List 1D, consisting of F.

[0250] Peptide moiety (P)P is a peptide moiety as defined herein. In this specification, the term “peptide” may take its normal meaning of a chain of amino acids linked by peptide bonds, but may also take the meaning of a single amino acid residue.

[0251] In one embodiment, the peptide moiety P comprises 1 to 10 amino acid residues. In one embodiment, the peptide moiety P consists essentially of 1 to 10 amino acid residues. In one embodiment, the peptide moiety P consists of 1 to 10 amino acid residues. In one embodiment, the peptide moiety P comprises, consists essentially of or consists of 1 , 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acid residues. In one embodiment, the peptide moiety P comprises, consists essentially of or consists of 1 to 6 amino acid residues. In one embodiment, the peptide moiety P comprises, consists essentially of or consists of 1 to 5 amino acid residues. In one embodiment, the peptide moiety P comprises, consists essentially of or consists of 2 amino acid residues. In one embodiment, the peptide moiety P comprises, consists essentially of or consists of 3 amino acid residues. In one embodiment, the peptide moiety P comprises, consists essentially of or consists of 4 amino acid residues. In one embodiment, the peptide moiety P comprises, consists essentially of or consists of 5 amino acid residues.

[0252] In one embodiment, the peptide moiety P comprises, consists essentially of or consists of any of AA1, AA1-Gly, Val-Cit, Vai-Ala, Val-AA1, Val-AA1-Gly, AA1-Ala-Asn, Ala-Ala-Ala, Ala-Ala-Asn, Glu-Val-Cit, Glu-Val-AA1, Glu-Glu, Glu-Gly-Cit, Glu-Gly-AA1, or Gly-Gly-AA1-Gly where AA1represents any amino acid residue, for example those as defined below.

[0253] In one embodiment, the peptide moiety P comprises, consists essentially of or consists of any of AA2, AA2-Gly, Val-Cit, Vai-Ala, Val-AA2, Val-AA2-Gly, AA2-Ala-Asn, Ala-Ala-Ala, Ala-Ala-Asn, Glu-Val-Cit, Glu-Val-AA2, Glu-Glu, Glu-Gly-Cit, Glu-Gly-AA2, or Gly-Gly-AA2-Gly where AA2represents an aromatic amino acid residue. In this specification “aromatic amino acid residue” encompasses any amino acid residue wherein the side chain is an aryl or heteroaryl group, as defined above, which may be substituted with any substituent selected from List 1 , as defined above.

[0254] In one embodiment, the peptide moiety P comprises, consists essentially of or consists of any of AA1, AA1-Gly, Val-Cit, Val-Ala, Val-AA1, Val-AA1-Gly, AA1-Ala-Asn, Ala-Ala-Ala, Ala-Ala-Asn, Glu-Val-Cit, Glu-Val-AA1, Glu-Glu, Glu-Gly-Cit, Glu-Gly-AA1, Gly-Gly-Phe-Gly (GGFG) or Gly-Gly-Pya-Gly, where AA1represents any amino acid residue as defined below, and Pya represents a (2-pyridyl)alanine, (3-pyridyl)alanine or (4-pyridyl)alanine residue.In one embodiment, the peptide moiety P comprises, consists essentially of or consists of

[0255] Val-AA1-Gly, where AA1represents

[0256]

[0257] In one embodiment, the peptide moiety P comprises, consists essentially of or consists of a GGFG peptide moiety (SEQ ID NO: 33).

[0258] In one embodiment, the peptide moiety P comprises, consists essentially of or consists of a GG(Pya)G peptide moiety wherein Pya represents a (2-pyridyl)alanine, (3-pyridyl)alanine or (4-pyridyl)alanine residue.

[0259] In one embodiment, the peptide moiety P comprises, consists essentially of or consists of a GG(Pya)G peptide moiety wherein Pya represents a (2-pyridyl)alanine residue. In one embodiment, the peptide moiety P comprises, consists essentially of or consists of a GG(Pya)G peptide moiety wherein Pya represents a (3-pyridyl)alanine residue. In one embodiment, the peptide moiety P comprises, consists essentially of or consists of a GG(Pya)G peptide moiety wherein Pya represents a (4-pyridyl)alanine residue.

[0260] AA7

[0261] In one embodiment, the amino acid residue represented by AA1is selected from

[0262]

[0263]

[0264] position 1 is connected, optionally via a further conjugation moiety, to the portion of the molecule bearing the binding molecule or fragment thereof, or the group Y which is capable of conjugating to the binding molecule or fragment thereof, and position 2 is connected, optionally via a further conjugation moiety, to the portion of the molecule bearing the payload compound.

[0265] is absent. In one embodiment, Q is a moiety of the formula:

[0266]

[0267] In one embodiment, Q is a moiety of the formula:

[0268]

[0269] wherein Re and R7have the meanings defined herein, either in the broadest aspect of any of the preferred aspects defined herein.

[0270] In one embodiment, Q is a moiety of the formula:

[0271]

[0272] wherein Re and R7have the meanings defined herein, either in the broadest aspect of any of the preferred aspects defined herein.

[0273] A’A’ is C2-10 alkylene. In one embodiment, A’ is C2-8 alkylene. In one embodiment, A’ is C2-6 alkylene. In one embodiment, A’ is C2-4 alkylene. In one embodiment, A is ethylene. In one embodiment, A’ is 1,2-ethylene. In one embodiment, A’ is propylene. In one embodiment, A’ is 1,2-propylene. In one embodiment, A’ is 1,3-propylene. In one embodiment, A’ is butylene. In one embodiment, A’ is 1,2-butylene. In one embodiment, A’ is 1,3-butylene. In one embodiment, A’ is 1,4-butylene. In one embodiment, A’ is pentylene. In one embodiment, A’ is 1,2-pentylene. In one embodiment, A’ is 1,3-pentylene. In one embodiment, A’ is 1,4-pentylene. In one embodiment, A’ is 1,5-pentylene. In one embodiment, A’ is hexylene. In one embodiment, A’ is 1 ,2-hexylene. In one embodiment, A’ is 1,3-hexylene. In one embodiment, A’ is 1 ,4-hexylene. In one embodiment, A’ is 1,5-hexylene. In one embodiment, A’ is 1 ,6-hexylene.

[0274] Payload Compounds - Formula (I)

[0275] The payload compounds of the invention are compounds of formula (I):

[0276]

[0277] or a pharmaceutically acceptable salt or solvate thereof,

[0278] wherein X, II, A, R1, R2, R3, R4 and Rs have the meanings defined herein, either in the broadest aspect or any of the preferred aspects defined herein.

[0279] In one embodiment, for compounds of formula (I), R1 is Ci-6-alkyl. In one embodiment, R1 is C1-5 alkyl. In one embodiment, R1 is C1-4 alkyl. In one embodiment, R1 is C1-3 alkyl. In one embodiment, R1 is Me or Et. In one embodiment, R1 is Me.

[0280] In one embodiment, for compounds of formula (I), R1 is C2-6-alkyl. In one embodiment, R1 is C2-5 alkyl. In one embodiment, R1 is C2-4 alkyl. In one embodiment, R1 is C2-3 alkyl. In one embodiment, R1 is Et.In one embodiment, for compounds of formula (I), X is S, S(=O) or S(=O)2 or a bond. In one embodiment, for compounds of formula (I), X is S.

[0281] In one embodiment, for compounds of formula (I), Ri is C2-6-alkyl and X is S. In one embodiment, Ri is C2-5 alkyl and X is S. In one embodiment, R1 is C2-4 alkyl and X is S. In one embodiment, Ri is C2-3 alkyl and X is S. In one embodiment, Ri is Et and X is S.

[0282] In one embodiment, for compounds of formula (I), Ri is Cs-e-cycloalkyl. In one embodiment, Ri is C3-5-cycloalkyl. In one embodiment, Ri is C3-4-cycloalkyl. In one embodiment, Ri is cyclopropyl.

[0283] In one embodiment for compounds of formula (I), Ri is Me, Et or Cs-e-cycloalkyl. In one embodiment, Ri is Me or Cs-e-cycloalkyl. In one embodiment, Ri is Et or Cs-e-cycloalkyl.

[0284] In one embodiment, the payload compounds of Formula (I) are compounds of Formula (l-Y):

[0285]

[0286] or a pharmaceutically acceptable salt or solvate thereof,

[0287] wherein:

[0288] II is O or S;

[0289] X is O, S, S(=O) or S(=O)2;

[0290] A is C2-10 alkylene, C2-10 alkenylene, C2- alkynylene, C3-10 cycloalkylene, C3-10 cycloalkenylene, Cs- cycloalkynylene, C3-10 heterocycloalkylene, C3-10 heterocycloalkenylene, or Cs- heterocycloalkynylene, each optionally substituted with one or more substituents selected from List 1 ;

[0291] either: Ri is C1-6 alkyl or C3-6 cycloalkyl, and R4 is H, C1-6 alkyl or C3-6 cycloalkyl,or: Ri and R4 together with the carbon atoms to which they are attached form a 5- to 7-membered carbocyclic ring which is substituted by a group -NH-C(=O)-Rs;

[0292] R2 is halogen or C1-6 alkyl;

[0293] R3 is C1-6 alkyl; and

[0294] Rs is C1-6 alkyl or-NR’R”, wherein R’ and R” are each independently H or C1-6 alkyl; provided that when X is O and R1 is ethyl, A is not C2-3 alkylene.

[0295] In one embodiment, for compounds of formula (l-Y), R1 is Ci-6-alkyl. In one embodiment, R1 is C1-5 alkyl. In one embodiment, R1 is C1-4 alkyl. In one embodiment, R1 is C1-3 alkyl. In one embodiment, R1 is Me or Et. In one embodiment, R1 is Me.

[0296] In one embodiment, for compounds of formula (l-Y), R1 is C2-6-alkyl. In one embodiment, R1 is C2-5 alkyl. In one embodiment, R1 is C2-4 alkyl. In one embodiment, R1 is C2-3 alkyl. In one embodiment, R1 is Et.

[0297] In one embodiment, for compounds of formula (l-Y), R1 is Cs-e-cycloalkyl. In one embodiment, R1 is Cs-s-cycloalkyl. In one embodiment, R1 is C3-4-cycloalkyl. In one embodiment, R1 is cyclopropyl.

[0298] In one embodiment for compounds of formula (l-Y), R1 is Me, Et or Cs-e-cycloalkyl. In one embodiment, R1 is Me or Cs-e-cycloalkyl. In one embodiment, R1 is Et or Cs-e-cycloalkyl.

[0299] In one embodiment, for compounds of formula (l-Y), X is S, S(=O) or S(=O)2 or a bond. In one embodiment, for compounds of formula (l-Y), X is S.

[0300] In the embodiment wherein R1 and R4 together with the carbon atoms to which they are attached form a 5- to 7-membered carbocyclic ring which is substituted by a group -NH-C(=O)-Rs, the compounds are of formula (IA):

[0301]

[0302] wherein:

[0303] II, X, A, R2, R3, and Rs have the meanings defined herein, either in the broadest aspect of any of the preferred aspects recited herein,

[0304] n is 0, 1 , 2; and m is 0, 1 or 2, with the proviso that m+n must be 1 , 2 or 3.

[0305] In one embodiment, m is 0. In one embodiment, n is 1. In one embodiment, n is 2.

[0306] In one embodiment, n is 0. In one embodiment, n is 1. In one embodiment, n is 2.

[0307] In the payload compounds of formula (I) as defined above, including those of formula (l-Y) and (IA) as defined above, the variables, X, II, A, R1, R2, R3, R4 and Rs may take any of the meanings defined above for these substituents, either in the broadest embodiments or any of the narrower embodiments defined herein.

[0308] In one embodiment, the compound of formula (I) is a compound of formula 1-1 through 1-15, as shown in Table 1 below, or a pharmaceutically acceptable salt or solvate thereof:

[0309]

[0310]

[0311]

[0312]

[0313]

[0314] In one embodiment, the compound is other than 1-1 in Table 1.

[0315] In one embodiment, the compound is other than I-2 in Table 1.

[0316] In one embodiment, when Ri is Et, R2 is F, R3 is Et, R4 is H, X and II are both O, then A is other than CH2 or CH2CH2.

[0317] In another aspect, there is provided a compound of formula (l-B):

[0318]

[0319] or a pharmaceutically acceptable salt or solvate thereof,

[0320] wherein:

[0321] II is O or S;

[0322] X is O, S, S(=O), orS(=O)2;

[0323] A is C2-10 alkylene, C2-10 alkenylene, C2- alkynylene, C3-10 cycloalkylene, C3-10 cycloalkenylene, Cs- cycloalkynylene, C3-10 heterocycloalkylene, C3-10 heterocycloalkenylene, or Cs- heterocycloalkynylene, each optionally substituted with one or more substituents selected from List 1 ;

[0324] either: R1 is Me or C3-6 cycloalkyl, and R4 is H or C1-6 alkyl,

[0325] or: R1 and R4 together with the carbon atoms to which they are attached form a 5- to 7-membered carbocyclic ring which is substituted by a group -NH-C(=O)-Rs;

[0326] R2 is halogen or C1-6 alkyl;

[0327] R3 is C1-6 alkyl; and

[0328] Rs is C1-6 alkyl or-NR’R”, wherein R’ and R” are each independently H or C1-6 alkyl.

[0329] In another aspect, there is provided a compound of formula (l-C):

[0330]

[0331] or a pharmaceutically acceptable salt or solvate thereof,

[0332] wherein:

[0333] II is O or S;

[0334] X is S, S(=O), orS(=O)2;

[0335] A is C2-10 alkylene, C2-10 alkenylene, C2- alkynylene, C3-10 cycloalkylene, C3-10 cycloalkenylene, Cs- cycloalkynylene, C3-10 heterocycloalkylene, C3-10 heterocycloalkenylene, or Cs- heterocycloalkynylene, each optionally substituted with one or more substituents selected from List 1 ;

[0336] either: R1 is H, C1-6 alkyl or C3-6 cycloalkyl, and R4 is H or C1-6 alkyl,

[0337] or: R1 and R4 together with the carbon atoms to which they are attached form a 5- to 7-membered carbocyclic ring which is substituted by a group -NH-C(=O)-Rs;

[0338] R2 is halogen or C1-6 alkyl;

[0339] R3 is C1-6 alkyl; and

[0340] Rs is C1-6 alkyl or-NR’R”, wherein R’ and R” are each independently H or C1-6 alkyl.

[0341] In one embodiment, the invention relates to a compound of formula (l-D):

[0342]

[0343] or a pharmaceutically acceptable salt or solvate thereof,

[0344] wherein:

[0345] II is O or S;

[0346] X is a bond;

[0347] A is C2-10 alkylene, C2-10 alkenylene, C2- alkynylene, C3-10 cycloalkylene, C3-10 cycloalkenylene, Cs- cycloalkynylene, C3-10 heterocycloalkylene, C3-10 heterocycloalkenylene, or Cs- heterocycloalkynylene, each optionally substituted with one or more substituents selected from List 1 ;Ri is H, C2-6 alkyl or C3-6 cycloalkyl;

[0348] R4 is H or C1-6 alkyl;

[0349] or R1 and R4 together with the carbon atoms to which they are attached form a 5- to 7-membered carbocyclic ring which is substituted by a group -NH-C(=O)-Rs;

[0350] R2 is halogen or C1-6 alkyl;

[0351] R3 is C1-6 alkyl; and

[0352] Rs is C1-6 alkyl or-NR’R”, wherein R’ and R” are each independently H or C1-6 alkyl.

[0353] In one embodiment, for compounds of formula (l-D):

[0354] II is O or S;

[0355] A is C2-6 alkylene or C3-6 cycloalkylene;

[0356] R2is as halogen, preferably F;

[0357] R3 is ethyl; and

[0358] R4 is H.

[0359] In one embodiment, the compound of formula (l-D) selected from the group consisting of compounds I-7, I-8, I-9, 1-11, 1-12 and 1-13 in Table 1, and pharmaceutically acceptable salts or solvates thereof.

[0360] In the linker-payload compounds of formula (I) as defined above, including those of formula (IA), (l-B), (l-C) and (l-D) as defined above, the variables X, II, A, R1, R2, R3, R4 and Rs may take any of the meanings defined above for these substituents, either in the broadest embodiment or any of the narrower embodiments defined herein.

[0361] Linkers (L)

[0362] L is a linker. L comprises a cleavable or non-cleavable linker. In one embodiment, L comprises a cleavable linker.

[0363] In one embodiment, L is an unbranched linker. In one embodiment, L is a linear linker.

[0364] In one embodiment, L is a bivalent linker that links a payload to a binding molecule, and wherein there is one binding molecule per linker.

[0365] In some embodiments, the linker L comprises a first conjugation moiety for coupling with the antibody or fragment thereof. Typically, the first conjugation moiety is represented by the group Y as defined herein.In one embodiment, the first conjugation moiety comprises a pyrimidine-sulfone moiety. In one embodiment, the first conjugation moiety comprises a pyrimidine-sulfone moiety wherein the sulfone moiety is present at the 2-position of the pyrimidine moiety and the pyrimidine moiety is attached to the rest of the molecule at the 5-position. In one embodiment, the pyrimidine-sulfone moiety is attached to a group -C(=O)-N(R)- (as defined below, either in its broadest aspect or a preferred aspect) at the 5-position.

[0366] In one embodiment, the first conjugation moiety comprises a maleimide moiety.

[0367] In one embodiment, the linker comprises a second conjugation moiety for coupling with the payload.

[0368] In some embodiments, the linker L comprises a peptide linker. In some embodiments, the linker consists essentially of a peptide linker. In some embodiments, the linker consists of a peptide linker. The peptide linker may take any of the forms defined above in relation to the moiety P.

[0369] In one embodiment, L comprises a moiety of the formula:

[0370] comprises a moiety of the formula:

[0371]

[0372] wherein Re and R7have the meanings defined herein, either in the broadest aspect of any of the preferred aspects defined herein.

[0373] In one embodiment, L comprises a moiety of the formula:

[0374]

[0375] wherein Re and R7have the meanings defined herein, either in the broadest aspect of any of the preferred aspects defined herein.

[0376] In one embodiment, L comprises a moiety of the formula:

[0377]

[0378] wherein:

[0379] P is a peptide moiety as defined herein, either in the broadest aspect of any of the preferred aspects defined herein, the C-terminus of the peptide moiety P being bonded to the -NH-moiety of the group Q when present;

[0380] Q is as defined herein, either in the broadest aspect of any of the preferred aspects defined herein:

[0381] A’ is C2-10 alkylene;

[0382] position (1) being the N-terminus of the peptide moiety P; and

[0383] position (2) being bonded to the O atom of the -L-O- moiety in formula (II).

[0384] In one embodiment, L comprises a moiety of the formula:

[0385]

[0386] wherein:

[0387] P is a peptide moiety as defined herein, either in the broadest aspect of any of the preferred aspects defined herein, the C-terminus of the peptide moiety P being bonded to the -NH-moiety of the group Q when present;

[0388] Q is as defined herein, either in the broadest aspect of any of the preferred aspects defined herein:

[0389] position (1) being the N-terminus of the peptide moiety P; and

[0390] position (2) being bonded to the II atom of the -L-U- moiety in formula (II) or (II’).

[0391] In one embodiment, L comprises, consists essentially or consists of a moiety -C(=O)-N(R)-wherein R is C1-6 alkyl. In some embodiments, L comprises, consists essentially or consists of a moiety -C(=O)-N(R)- wherein R is C1-4 alkyl. In some embodiments, L comprises, consists essentially or consists of a moiety -C(=O)-N(R)- wherein R is C1-3 alkyl. In some embodiments, L comprises, consists essentially or consists of a moiety -C(=O)-N(R)-wherein R is methyl or ethyl. In some embodiments, L comprises, consists essentially or consists of a moiety -C(=O)-N(R)- wherein R is methyl.

[0392] In one embodiment, L comprises, consists essentially or consists of an ethylene glycol moiety or poly(ethylene glycol) moiety. As is known to the person skilled in the art, the ethylene glycol moiety is a moiety of formula (-CH2-CH2-O-). In one embodiment, L comprises, consists essentially or consists of 1 to 50 ethylene glycol moieties. In one embodiment, L comprises, consists essentially or consists of 1 to 30 ethylene glycol moieties. In one embodiment, L comprises, consists essentially or consists of 1 to 20 ethylene glycol moieties. In one embodiment, L comprises, consists essentially or consists of 1 to 10, such as 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 ethylene glycol moieties.

[0393] In one embodiment, L comprises, consists essentially or consists of an alkylene group, as defined herein, either in its broadest aspect or any of the preferred aspects recited herein. In one embodiment, L comprises, consists essentially or consists of a C1-10 alkylene group, such as a Ci, C2, C3, C4, C5, Ce, C7, Cs, C9 or C10 alkylene group.

[0394] In one embodiment, L comprises, consists essentially or consists of an alkenylene group, as defined herein, either in its broadest aspect or any of the preferred aspects recited herein. In one embodiment, L comprises, consists essentially or consists of a C2-10 alkenylene group, such as a C2, C3, C4, C5, Cs, C7, Cs, C9 or C10 alkenylene group.

[0395] In one embodiment, L comprises, consists essentially or consists of an alkynylene group, as defined herein, either in its broadest aspect or any of the preferred aspects recited herein. In one embodiment, L comprises, consists essentially or consists of a C2-10 alkynylene group, such as a C2, C3, C4, Cs, Cs, C7, Cs, C9 or C10 alkynylene group.

[0396] In one embodiment, L comprises, consists essentially or consists of a cycloalkylene group, as defined herein, either in its broadest aspect or any of the preferred aspects recited herein. In one embodiment, L comprises, consists essentially or consists of a C3-10 cycloalkylene group, such as a C3, C4, Cs, Cs, C7, Cs, C9 or C10 cycloalkylene group.

[0397] In one embodiment, L comprises, consists essentially or consists of a cycloalkenylene group, as defined herein, either in its broadest aspect or any of the preferred aspects recited herein. In one embodiment, L comprises, consists essentially or consists of a C3-10 cycloalkenylene group, such as a C3, C4, Cs, Cs, C7, Cs, C9 or C10 cycloalkenylene group.In one embodiment, L comprises, consists essentially or consists of a cycloalkynylene group, as defined herein, either in its broadest aspect or any of the preferred aspects recited herein. In one embodiment, L comprises, consists essentially or consists of a Cs- cycloalkenylene group, such as a Cs, C9 or C10 cycloalkynylene group.

[0398] In one embodiment, L comprises, consists essentially or consists of a moiety of the formula:

[0399]

[0400] wherein:

[0401] P is a peptide moiety as defined herein, and the C-terminus of the peptide moiety P being bonded to the -NH-moiety of Q when present;

[0402] Q is absent or is a moiety of the formula:

[0403]

[0404] wherein Re and R7 are each independently H or C1-6 alkyl, or Re and R7 together with the carbon atom to which they are attached form a 3- to 10-membered carbocyclic ring;

[0405] A’ is C2-10 alkylene;

[0406] position (1) being the N-terminus of the peptide moiety P; and

[0407] position (2) being bonded to the II atom of the -L-U- moiety in formula (II) or (III).

[0408] In one embodiment, L comprises, consists essentially or consists of a moiety of the formula:

[0409]

[0410] wherein:

[0411] P is a peptide moiety as defined herein, and the C-terminus of the peptide moiety P being bonded to the -NH-moiety of Q when present;

[0412] Q is absent or is a moiety of the formula:

[0413]

[0414] wherein Re and R7 are each independently H or C1-6 alkyl, or Re and R7 together with the carbon atom to which they are attached form a 3- to 10-membered carbocyclic ring;position (1) being the N-terminus of the peptide moiety P; and

[0415] position (2) being bonded to the II atom of the -L-U- moiety in formula (II) or (III).

[0416] In one embodiment, L comprises, consists essentially or consists of a group of formula (LX’):

[0417]

[0418] wherein:

[0419] R is as defined herein for the group -C(=O)-N(R)-;

[0420] EO is an ethylene glycol moiety, the terminal carbon of which is attached to the group -N(R)-and the terminal oxygen of which is attached to the group -(CH2)W-;

[0421] v is 0 or 1 to 40;

[0422] w is 0 or 1 to 10;

[0423] P is a peptide moiety as defined herein;

[0424] Q is as defined herein;

[0425] A’ is as defined herein;

[0426] position (1) being attached to the group Y in formula (II) or to the connecting atom (typically a sulphur atom) on the binding molecule BM in formula (III); and

[0427] position (2) being bonded to the II atom of the -L-U- moiety in formula (II) or (III).

[0428] In one embodiment, L comprises, consists essentially or consists of a group of formula (LX):

[0429]

[0430] wherein:

[0431] R is as defined herein for the group -C(=O)-N(R)-;

[0432] EO is an ethylene glycol moiety, the terminal carbon of which is attached to the group -N(R)-and the terminal oxygen of which is attached to the group -(CH2)W-;

[0433] v is 0 or 1 to 40;

[0434] w is 0 or 1 to 10;

[0435] P is a peptide moiety as defined herein;

[0436] Q is as defined herein;

[0437] position (1) being attached to the group Y in formula (II) or to the connecting atom (typically a sulphur atom) on the binding molecule BM in formula (III); andposition (2) being bonded to the II atom of the -L-U- moiety in formula (II) or (III).

[0438] In the linkergroup of formula (LX), R is C1-6 alkyl. In some embodiments, R is C1-4 alkyl. In some embodiments, R is C1-3 alkyl. In some embodiments, R is methyl or ethyl. In some embodiments, R is methyl.

[0439] In the linkergroup of formula (LX), v is 0 or 1 to 40, such as 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39 or 40. In some embodiments, v is 0 or 1 to 30. In some embodiments, v is 0 or 1 to 20. In some embodiments, v is 0 or 1 to 10. In some embodiments, v is 0 or 1 to 8. In some embodiments, v is 0 or 1 to 7. In some embodiments, v is 0 or 1 to 6. In some embodiments, v is 0 or 1 to 5. In some embodiments, v is 0 or 1 to 4. In some embodiments, v is 0 or 1 to 3. In some embodiments, v is 2 to 10. In some embodiments, v is 2 to 8. In some embodiments, v is 2 to 7. In some embodiments, v is 2 to 6. In some embodiments, v is 2 to 5. In some embodiments, v is 2 to 4. In some embodiments, v is 2. In some embodiments, v is 0.

[0440] In the linkergroup of formula (LX), w is 0 or 1 to 10, such as 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10. In some embodiments, w is 0 or 1 to 8. In some embodiments, w is 0 or 1 to 6. In some embodiments, w is 0 or 1 to 5. In some embodiments, w is 0 or 1 to 4. In some embodiments, w is 0 or 1 to 3. In some embodiments, w is 1 or 2. In some embodiments, w is 0 or 1. In some embodiments, w is 0. In some embodiments, w is 1.

[0441] In the linker group of formula (LX), the peptide moiety P may take any of the meanings defined generally herein, either in its broadest aspect or a preferred aspect.

[0442] In one embodiment of formula (LX), the peptide moiety P comprises, consists essentially of or consists of any of AA1, AA1-Gly, Val-Cit, Val-Ala, Val-AA1, Val-AA1-Gly, AA1-Ala-Asn, Ala-Ala-Ala, Ala-Ala-Asn, Glu-Val-Cit, Glu-Val-AA1, Glu-Glu, Glu-Gly-Cit, Glu-Gly-AA1, or Gly-Gly-AA1-Gly where AA1represents any amino acid residue as defined below.

[0443] In one embodiment of formula (LX), the peptide moiety P comprises, consists essentially of or consists of any of AA2, AA2-Gly, Val-Cit, Val-Ala, Val-AA2, Val-AA2-Gly, AA2-Ala-Asn, Ala-Ala-Ala, Ala-Ala-Asn, Glu-Val-Cit, Glu-Val-AA2, Glu-Glu, Glu-Gly-Cit, Glu-Gly-AA2, or Gly-Gly-AA2-Gly where AA2represents an aromatic amino acid residue. In this specification “aromatic amino acid residue” encompasses any amino acid residue wherein the side chainis an aryl or heteroaryl group, as defined above, which may be substituted with any substituent selected from List 1, as defined above.

[0444] In one embodiment of formula (LX), the peptide moiety P comprises, consists essentially of or consists of any of AA1, AA1-Gly, Val-Cit, Val-Ala, Val-AA1, Val-AA1-Gly, AA1-Ala-Asn, Ala-Ala-Ala, Ala-Ala-Asn, Glu-Val-Cit, Glu-Val-AA1, Glu-Glu, Glu-Gly-Cit, Glu-Gly-AA1, Gly-Gly-Phe-Gly (GGFG) or Gly-Gly-Pya-Gly, where AA1represents any amino acid residue, and Pya represents a (2-pyridyl)alanine, (3-pyridyl)alanine or (4-pyridyl)alanine residue.

[0445] In one embodiment of formula (LX), the peptide moiety P comprises, consists essentially of

[0446] or consists of Val-AA1-Gly, where AA1represents

[0447]

[0448] .

[0449] In one embodiment of formula (LX), the peptide moiety P comprises, consists essentially of or consists of a GGFG peptide moiety.

[0450] In one embodiment of formula (LX), the peptide moiety P comprises, consists essentially of or consists of a GG(Pya)G peptide moiety wherein Pya represents a (2-pyridyl)alanine, (3-pyridyl)alanine or (4-pyridyl)alanine residue.

[0451] In one embodiment of formula (LX), the peptide moiety P comprises, consists essentially of or consists of a GG(Pya)G peptide moiety wherein Pya represents a (2-pyridyl)alanine residue.

[0452] In the linker group of formula (LX), Q is absent or is a moiety of the formula:

[0453]

[0454] wherein Re and R? are as defined herein, either in its broadest aspect or a preferred aspect. Preferably Re and R? are both H.

[0455] In the linker group of formula (LX), Q is absent or is a moiety of the formula:

[0456]

[0457] wherein Re and R? are as defined herein, either in its broadest aspect or a preferred aspect. Preferably Re and R? are both H.

[0458] In one embodiment of formula (LX’), the group A’ is as defined herein, either in its broadest aspect or a preferred aspect. In one embodiment, A’ is C2-4 alkylene. In one embodiment, A’ is 1,2-ethylene. In one embodiment, A’ is 1,3-propylene. In one embodiment, A’ is 1,4-butylene.

[0459] In one embodiment, L is a group of formula (LT):

[0460]

[0461] wherein:

[0462] x is 1, 2, or 3;

[0463] position (1) is attached to the group Y in formula (II) or to the connecting atom (typically a sulphur atom) on the binding molecule BM in formula (III); and

[0464] position (2) is bonded to the II atom of the -L-U- moiety in formula (II) or (III).

[0465] In one embodiment, L is a group of formula (L1):

[0466]

[0467] wherein:position (1) is attached to the group Y in formula (II) or to the connecting atom (typically a sulphur atom) on the binding molecule BM in formula (III); and

[0468] position (2) is bonded to the II atom of the -L-U- moiety in formula (II) or (III).

[0469] In one embodiment, L is a group of formula (L2’):

[0470]

[0471] wherein:

[0472] x is 1, 2, or 3;

[0473] position (1) is attached to the group Y in formula (II) or to the connecting atom (typically a sulphur atom) on the binding molecule BM in formula (III); and

[0474] position (2) is bonded to the II atom of the -L-U- moiety in formula (II) or (III).

[0475] In one embodiment, L is a group of formula (L2):

[0476]

[0477] wherein:

[0478] position (1) is attached to the group Y in formula (II) or to the connecting atom (typically a sulphur atom) on the binding molecule BM in formula (III); and

[0479] position (2) is bonded to the U atom of the -L-U- moiety in formula (II) or (III).

[0480] In one embodiment, L is a group of formula (L3’):

[0481]

[0482] wherein:x is 1, 2, or 3;

[0483] position (1) is attached to the group Y in formula (II) or to the connecting atom (typically a sulphur atom) on the binding molecule BM in formula (III); and

[0484] position (2) is bonded to the II atom of the -L-U- moiety in formula (II) or (III).

[0485] In one embodiment, L is a group of formula (L3):

[0486]

[0487] wherein:

[0488] position (1) is attached to the group Y in formula (II) or to the connecting atom (typically a sulphur atom) on the binding molecule BM in formula (III); and

[0489] position (2) is bonded to the II atom of the -L-U- moiety in formula (II) or (III).

[0490] In one embodiment, L is a group of formula (L4):

[0491]

[0492] wherein:

[0493] position (1) is attached to the group Y in formula (II) or to the connecting atom (typically a sulphur atom) on the binding molecule BM in formula (III); and

[0494] position (2) is bonded to the U atom of the -L-U- moiety in formula (II) or (III).

[0495] In one embodiment, L is a group of formula (L5):

[0496]

[0497] wherein:

[0498] position (1) is attached to the group Y in formula (II) or to the connecting atom (typically a sulphur atom) on the binding molecule BM in formula (III); and

[0499] position (2) is bonded to the U atom of the -L-U- moiety in formula (II) or (III).Linker-Payload Conjugates - Formula (II)

[0500] The linker-payload conjugates of the invention are compounds of formula (II):

[0501]

[0502] or a pharmaceutically acceptable salt or solvate thereof,

[0503] wherein:

[0504] X, A, Ri, R2, R3, R4 and Rs are as defined herein, either in its broadest aspect or any of the preferred aspects recited herein;

[0505] L is a linker as defined herein, either in its broadest aspect or any of the preferred aspects recited herein; and

[0506] Y is a group capable of conjugating with a binding molecule to generate a conjugate, either in its broadest aspect or any of the preferred aspects recited herein.

[0507] In one embodiment, the invention relates to a compound of formula (ll-YY):

[0508]

[0509] or a pharmaceutically acceptable salt or solvate thereof,

[0510] wherein:

[0511] X, II, A, Ri, R2, R3, R4 and Rs are as defined above for formula (l-Y);

[0512] L is a linker as defined herein; and

[0513] Y is a group capable of conjugating with a binding molecule to generate a conjugate.

[0514] In one embodiment, the invention relates to a compound of formula (ll-B):

[0515]

[0516] or a pharmaceutically acceptable salt or solvate thereof,

[0517] wherein:

[0518] X, II, A, R1, R2, R3, R4 and Rs are as defined above for formula (l-B);

[0519] L is a linker as defined herein; and

[0520] Y is a group capable of conjugating with a binding molecule to generate a conjugate.

[0521] In one embodiment, the invention relates to a compound of formula (I l-C):

[0522]

[0523] or a pharmaceutically acceptable salt or solvate thereof,

[0524] wherein:

[0525] X, II, A, Ri, R2, R3, R4 and Rs are as defined above for formula (l-C);

[0526] L is a linker as defined herein; and

[0527] Y is a group capable of conjugating with a binding molecule to generate a conjugate.

[0528] In one embodiment, the invention relates to a compound of formula (ll-D):

[0529]

[0530] or a pharmaceutically acceptable salt or solvate thereof,

[0531] wherein:

[0532] X, II, A, R1 , R2, R3, R4 and Rs are as defined above for formula (l-D);

[0533] L is a linker as defined herein; and

[0534] Y is a group capable of conjugating with a binding molecule to generate a conjugate.

[0535] In one embodiment, the linker-payload conjugates of formula (II) are compounds of formula (ll-Y):

[0536]

[0537] or a pharmaceutically acceptable salt or solvate thereof,

[0538] wherein:

[0539] II is O or S;

[0540] X is a bond, O, S, S(=O) or S(=O)2;

[0541] when X is O, S, S(=O) or S(=O)2, A is C2-10 alkylene, C2-10 alkenylene, C2- alkynylene, C3-10 cycloalkylene, C3-10 cycloalkenylene, Cs- cycloalkynylene, C3-10 heterocycloalkylene, C3-10 heterocycloalkenylene, or Cs- heterocycloalkynylene, each optionally substituted with one or more substituents selected from List 1 ;

[0542] when X is a bond, A is C1-10 alkylene, C2-10 alkenylene, C2- alkynylene, C3-10 cycloalkylene, C3-10 cycloalkenylene, Cs- cycloalkynylene, C3-10 heterocycloalkylene, C3-10 heterocycloalkenylene, or Cs- heterocycloalkynylene, each optionally substituted with one or more substituents selected from List 1 ;

[0543] R1 and R4 are each independently H, C1-6 alkyl, or C3-10 cycloalkyl, or R1 and R4 together with the carbon atoms to which they are attached form a 5- to 7-membered carbocyclic ring which is substituted by a group -NH-C(=O)-Rs;

[0544] R2 is H, halogen or C1-6 alkyl;

[0545] R3 is C1-6 alkyl; and

[0546] Rs is C1-6 alkyl or-NR’R”, wherein R’ and R” are each independently H or C1-6 alkyl;

[0547] L is a linker of formula (LX”):

[0548]

[0549] wherein:

[0550] R is C1-6 alkyl;

[0551] EO is an ethylene glycol moiety, the terminal carbon of which is attached to the group -N(R)-and the terminal oxygen of which is attached to the group -(CH2)W- when w is 1 to 10, or to the - C(=O) group when w is 0;

[0552] v is 0 or 1 to 40;

[0553] w is 0 or 1 to 10;

[0554] P is a peptide moiety consisting of 1 to 10 amino acid residues;

[0555] Re and R? are each independently H or C1-6 alkyl, or Re and R? together with the carbon atom to which they are attached form a 3- to 10-membered carbocyclic ring;

[0556] position (1) is a first attachment point; and

[0557] position (2) is a second attachment point; and

[0558] Y is a group capable of conjugating with a binding molecule to generate a conjugate.In one embodiment, position (1) is bonded to the group Y in formula (I l-Y); and position (2) is bonded to the II atom of the -L-U- moiety.

[0559] In the embodiment wherein R1 and R4 together with the carbon atoms to which they are attached form a 5- to 7-membered carbocyclic ring which is substituted by a group -NH-C(=O)-Rs, the compounds are of formula (IIA):

[0560]

[0561] wherein Y, L, II, X, A, R2, R3, and Rs have the meanings defined herein, either in the broadest aspect of any of the preferred aspects recited herein,

[0562] n is 0, 1 , or 2; and m is 0, 1 or 2, with the proviso that m+n must be 1 , 2 or 3.

[0563] In one embodiment, m is 0. In one embodiment, m is 1. In one embodiment, m is 2.

[0564] In one embodiment, n is 0. In one embodiment, n is 1. In one embodiment, n is 2.

[0565] In the linker-payload compounds of formula (II) as defined above, including those of formula (IIA), (I l-Y), (ll-YY), (I l-B), (I l-C) and (ll-D) as defined above, the variables X, U, A, R1, R2, R3, R4 and Rs may take any of the meanings defined above for these substituents, either in the broadest embodiment or any of the narrower embodiments defined herein.

[0566] In the linker-payload conjugates of formula (II) of the present invention, including those of formula (IIA), (ll-YY), (I l-B), (I l-C) and (ll-D), the linker L may take any of the meanings asdefined herein, either in the broadest embodiment or any of the narrower embodiments defined herein.

[0567] In one embodiment of the linker-payload conjugates of formula (II) of the present invention, including those of formula (HA), (ll-YY), (I l-B), (I l-C) and (I l-D) , the linker L is of the formula (LX) or (LX”) as defined herein, either in the broadest embodiment or any of the narrower embodiments defined herein.

[0568] In one embodiment of the linker-payload conjugates of formula (II) of the present invention, including those of formula (HA), (H-Y), (H-YY), (H-B), (H-C) and (H-D), the linker L is of the formula (L1) as defined herein.

[0569] In one embodiment of the linker-payload conjugates of formula (II) of the present invention, including those of formula (HA), (H-Y), (H-YY), (H-B), (H-C) and (H-D), the linker L is of the formula (L2) as defined herein.

[0570] In one embodiment of the linker-payload conjugates of formula (II) of the present invention, including those of formula (HA), (H-Y), (H-YY), (H-B), (H-C) and (H-D), the linker L is of the formula (L3) as defined herein.

[0571] In one embodiment of the linker-payload conjugates of formula (II) of the present invention, including those of formula (HA), (H-Y), (H-YY), (H-B), (H-C) and (H-D), the linker L is of the formula (L4) as defined herein.

[0572] In one embodiment of the linker-payload conjugates of formula (II) of the present invention, including those of formula (HA), (H-Y), (H-YY), (H-B), (H-C) and (H-D), the linker L is of the formula (L5) as defined herein.

[0573] In one embodiment, the compound of formula (II) is a compound of formula 11-1 through II-51 , as shown in Table 2 below, or a pharmaceutically acceptable salt or solvate thereof:

[0574] >

[0575] >

[0576] >

[0577] >

[0578] > > >

[0579]

[0580] "

[0581] >

[0582] >

[0583] <

[0584] >

[0585] ><

[0586] >

[0587] < " <

[0588]

[0589] "

[0590]

[0591]

[0592] In the compounds of formulae (11-10) through (I I-27), Ac is -C(=O)-CH3.

[0593] Binding Molecule (BM)

[0594] The binding molecule-linker-payload compounds of the present invention comprises a binding molecule or fragment thereof that specifically binds to a target, typically a target expressed on the surface of a tumour cell.

[0595] In some embodiments, the binding molecule is not a polysaccharide.

[0596] In some embodiments the binding molecule may be an antibody or a fragment thereof. In some embodiments the antibody fragment is an antigen-binding fragment.

[0597] When the binding molecule is an antibody or a fragment thereof, the binding molecule-linker-payload compound may also be referred to as an “antibody-drug conjugate” (ADC). It will be understood by the skilled person that the term “antibody-drug conjugate” encompasses both specific antibody-drug conjugates of formula (III) wherein the binding molecule is an antibody, and having a DAR (as defined below) which is integral, and compositions (as defined below) comprising antibody-drug conjugates of formula (III’) wherein the binding molecule is an antibody, having different DARs, resulting in an average DAR (as defined below) which can be non-integral.

[0598] Targets which are expressed on the surface of a tumour cell may be identified by means of various molecular biological and immunological methods known in the art (see e.g. Carter,P., et al., 2004. Endocrine-related cancer, 11(4), pp.659-687). A target may be referred to as an antigen. An ideal expression profile is abundant and homogeneous antigen expression on the external surface of all tumour cells for multiple tumour types with the majority of patients for each tumour type, and absent from normal tissue. In some embodiments, the target is expressed on the surface of solid tumour cells.

[0599] In some embodiments, the target is expressed with higher expression on the surface of tumour cells as compared to healthy cells. In some embodiments, the target is expressed at a level sufficient to distinguish a tumour cell from healthy cells. Evaluation of antigen expression on the surface may be determined by any suitable method, for example by immunohistochemistry e.g. tissue microarray immunohistochemistry (see e.g. Hoos, A. and Cordon-Cardo, C., 2001. Laboratory investigation, 81(10), pp.1331-1338).

[0600] Example targets may include B7H3, TROP2, HER2, HER3, ALK receptor (pleiotrophin receptor); ovarian carcinoma antigen (CA125); prostate-specific antigen (PSA); melanoma-associated antigen p97; melanoma antigen gp75; high molecular weight melanoma antigen (HMW-MAA); prostate-specific membrane antigen (PSMA); carcinoembryonic antigen (CEA); polymorphic epithelial mucin antigen; CD19; human B-lymphoma antigen-CD20; CD33; melanoma-specific antigens such as ganglioside GD2, ganglioside GD3, ganglioside GM2, and ganglioside GM3; epidermal growth factor receptor (EGFR); NY-BR-16; NY-BR-16; polymorphic epithelial mucin (PEM); malignant human lymphocyte antigen-APO-1; SSEA-1; SCP-1; SSEA-3; SSEA-4; sialyl Tn (STn); colon cancer antigen NY-CO-45; lung cancer antigen NY-LU-12 variant A; adenocarcinoma antigen ART1; Neuro-oncological ventral antigen 2 (NOVA2); tumor-associated antigens MAGE-C1 (cancer / testis antigen CT7), MAGE-B1 (MAGE-XP antigen), MAGE-B2 (DAM6), MAGE-2, MAGE-4a, MAGE-4b and MAGE-X2; Cancer-Testis Antigen (NY-EOS-1); YKL-40; EpCAM; EREG; CA15-3; sialyl SSEA-1 (SLX); CLDN6; CLDN18.2 and Mesothelin. In some embodiments, the target is selected from B7H3, TROP2, HER2, and HER3.

[0601] In some embodiments, the target expressed on the surface of a tumour cell is HER2, B7H3 orTROP2.

[0602] Wherein the binding molecule or fragment thereof is an antibody or fragment thereof that specifically binds to a target expressed on the surface of a tumour cell, this may be selected from the group consisting of a human antibody, a humanized antibody, a chimeric antibody, a multispecific antibody, a monoclonal antibody, a polyclonal antibody, a bispecific antibody, and fragments thereof, such as antigen-binding fragments thereof. In this respect, it will be understood by the skilled person that the term “antibody-drug conjugate” applies irrespective of whether the binding moiety is an antibody or a fragment thereof.In some embodiments, the antibody or fragment thereof that specifically binds to a target expressed on the surface of a tumour cell is a full-length antibody, such as a human antibody, a humanized antibody, a chimeric antibody, a multispecific antibody, a bispecific antibody, a monoclonal antibody, or a polyclonal antibody. In some embodiments, the antibody or fragment thereof that specifically binds to a target expressed on the surface of a tumour cell is a human antibody, a humanized antibody, or a chimeric antibody. In some embodiments, the antibody or fragment thereof that specifically binds to a target expressed on the surface of a tumour cell is a monoclonal antibody, for example a monoclonal human antibody, a monoclonal humanized antibody, or a monoclonal chimeric antibody.

[0603] In other embodiments, the antibody or fragment thereof that specifically binds to a target expressed on the surface of a tumour cell is an antibody fragment, such as a Fab, a Fab', a F(ab')2, an Fv, an scFv, a Fab'-SH, an sdAb, or a VHH.

[0604] In some embodiments the antibody or antigen-binding thereof is a VHH.

[0605] In some embodiments, the antibody or fragment thereof comprises an immunoglobulin constant region. In some embodiments, the immunoglobulin constant region is a human IgG constant region, for example a human lgG1, lgG2, lgG3 or lgG4 constant region. In some embodiments, the immunoglobulin constant region is a human lgG1 constant region.

[0606] In some embodiments, the antibody or fragment thereof comprises an Fc region. In some embodiments, the Fc region is a human Fc region, for example a human lgG1, lgG2, lgG3 or lgG4 Fc region. In some embodiments, the antibody or fragment thereof comprises a human lgG1 Fc region.

[0607] In some embodiments the antibody or antigen-binding fragment thereof comprises a VHH coupled to an Fc region. In this embodiment the Fc region may be as defined above.

[0608] In some embodiments, the antibody or fragment thereof comprises an Fc region comprising one or more mutations which reduce or abolish immune effect functions. Suitable mutations are known in the art and may include one or more amino acid substitutions (see e.g.

[0609] Wilkinson, I., et al., 2021. FcPLoS One, 16(12), p.e0260954; and Liu, R., et al., 2020.

[0610] Antibodies, 9(4), p.64). In some embodiments, the antibody or fragment thereof comprises an lgG1 Fc region comprising a L234A and / or a L235A mutation. In some embodiments, the antibody or fragment thereof comprises an I gG 1 Fc region comprising L234A and L235A mutations. Amino acids are numbered according to the Eu numbering (Eu-index) as set forth in Kabat (Kabat, E.A.; National Institutes of Health (U.S.) Office of the Director. Sequencesof Proteins of Immunological Interest, 5th ed.; DIANE Publishing: Collingdale, PA, USA, 1991).

[0611] In some embodiments the Fc region is silenced to reduce, negate or abolish one or more Fc receptor binding and / or functionalities. In some embodiments, the Fc region of the binding molecule is modified to negate one or more Fc receptor functionalities. In some embodiments, the Fc region of the binding molecule is silenced in respect of one or more or all of FcyRI (CD64), FcyRlla (CD32A), FcyRllb (CD32B), FcyRIII (CD16) and C1q functionality.

[0612] Thus, in some embodiments, the Fc region of as defined herein is a modified Fc region. Suitable silencing mutations are well known in the art. For example, the Fc region of the binding molecule may comprise a silencing modification selected from the STR mutation, the LALA mutation and the delta A mutation.

[0613] Anti-B7H3 antibodies and fragments thereof

[0614] In some embodiments, the target expressed on the surface of a tumour cell is B7H3. B7H3 is a protein that in humans is encoded by the CD276 gene and which may also be known as Cluster of Differentiation 276 (CD276) and B7 Homolog 3 (B7-H3).

[0615] In some embodiments, the antibody-drug conjugate comprises an anti-B7H3 antibody or fragment thereof.

[0616] In some embodiments the antibody-drug conjugate comprises an anti-B7H3 antibody or a fragment thereof that binds, such as specifically binds, B7H3.

[0617] The anti-B7H3 antibody or fragment thereof may specifically bind B7H3. The anti-B7H3 antibody may be a monoclonal antibody. In some embodiments, the anti-B7H3 antibody or fragment thereof is a humanized antibody. In some embodiments, the anti-B7H3 antibody or fragment thereof is a monoclonal humanized antibody. The anti-B7H3 antibody or fragment thereof may be a bispecific antibody. The fragment thereof may be any antigen-binding fragment thereof, for example a Fab, a Fab', a F(ab')2, a Fv, a scFv, a Fab'-SH, an sdAb, or a VHH.

[0618] In some embodiments the antibody or antigen-binding fragment thereof comprises a VHH coupled to an Fc region.

[0619] In some embodiments, the anti-B7H3 antibody or fragment thereof is a full-length anti-B7H3 antibody.The anti-B7H3 antibody or fragment thereof may comprise a variable region that specifically binds B7H3. In some embodiments, the anti-B7H3 antibody or fragment thereof comprises a heavy chain variable region and / or a light chain variable domain. In some embodiments, the anti-B7H3 antibody or fragment thereof comprises a heavy chain variable region and a light chain variable domain. In some embodiments, the anti-B7H3 antibody or fragment thereof comprises a constant region, preferably derived from a human antibody, preferably the constant region is selected from the constant region of human lgG1, lgG2, lgG3 or lgG4. In some embodiments, the anti-B7H3 antibody or fragment thereof comprises a heavy chain and / or a light chain. In some embodiments, the anti-B7H3 antibody or fragment thereof comprises a heavy chain and a light chain. In some embodiments, the anti-B7H3 antibody or fragment thereof comprises or consists of two heavy chains and two light chains.

[0620] Anti-TROP2 antibodies and fragments thereof

[0621] In some embodiments, the target expressed on the surface of a tumour cell is TROP2.

[0622] TROP2 is a protein that in humans is encoded by the TACSTD2 and which may also be known as Tumour-associated calcium signal transducer 2, epithelial glycoprotein-1 antigen (EGP-1), orTrop-2.

[0623] In some embodiments, the antibody-drug conjugate comprises an anti-TROP2 antibody or fragment thereof.

[0624] In some embodiments the antibody-drug conjugate comprises an anti-TROP2 antibody or a fragment thereof that binds, such as specifically binds, TROP2.

[0625] The anti-TROP2 antibody or fragment thereof may specifically bind TROP2. The anti-TROP2 antibody may be a monoclonal antibody. In some embodiments, the anti-TROP2 antibody or fragment thereof is a humanized antibody. In some embodiments, the anti-TROP2 antibody or fragment thereof is a monoclonal humanized antibody. The anti-TROP2 antibody or fragment thereof may be a bispecific antibody. The fragment thereof may be any antigenbinding fragment thereof, for example a Fab, a Fab', a F(ab')2, a Fv, a scFv, a Fab'-SH, an sdAb, or a VHH. In some embodiments, the anti-TROP2 antibody or fragment thereof is a full-length anti-TROP2 antibody.

[0626] In some embodiments the antibody or antigen-binding fragment thereof comprises a VHH coupled to an Fc region.

[0627] The anti-TROP2 antibody or fragment thereof may comprise a variable region that specifically binds TROP2. In some embodiments, the anti-TROP2 antibody or fragment thereof comprises a heavy chain variable region and / or a light chain variable domain. Insome embodiments, the anti-TROP2 antibody or fragment thereof comprises a heavy chain variable region and a light chain variable domain. In some embodiments, the anti-TROP2 antibody or fragment thereof comprises a constant region, preferably derived from a human antibody, preferably the constant region is selected from the constant region of human lgG1, I gG2, lgG3 or lgG4. In some embodiments, the anti-TROP2 antibody or fragment thereof comprises a heavy chain and / or a light chain. In some embodiments, the anti-TROP2 antibody or fragment thereof comprises a heavy chain and a light chain. In some embodiments, the anti-TROP2 antibody or fragment thereof comprises or consists of two heavy chains and two light chains.

[0628] Example anti-TROP2 antibody sequences

[0629] Example anti-TROP2 antibody CDRs, variable region sequences, and heavy and light chain sequences are provided below.

[0630]

[0631] In some embodiments, a heavy chain variable region of the anti-TROP2 antibody or fragment thereof comprises: (i) a HCDR1 comprising or consisting of the amino acid sequence of SEQ ID NO: 1 , or a variant thereof having up to three amino acid substitutions, additions or deletions; (ii) a HCDR2 comprising or consisting of the amino acid sequence of SEQ ID NO: 2, or a variant thereof having up to three amino acid substitutions, additions or deletions; and (iii) a HCDR3 comprising or consisting of the amino acid sequence of SEQ ID NO: 3, or a variant thereof having up to three amino acid substitutions, additions or deletions, wherein the CDRs are defined according to the Kabat numbering system.

[0632] In some embodiments, a light chain variable region of the anti-TROP2 antibody or fragment thereof comprises: (i) a LCDR1 comprising or consisting of the amino acid sequence of SEQ ID NO: 4, or a variant thereof having up to three amino acid substitutions, additions or deletions; (ii) a LCDR2 comprising or consisting of the amino acid sequence of SEQ ID NO: 5, or a variant thereof having up to three amino acid substitutions, additions or deletions; and (iii) a LCDR3 comprising or consisting of the amino acid sequence of SEQ ID NO: 6, or a variant thereof having up to three amino acid substitutions, additions or deletions, wherein the CDRs are defined according to the Kabat numbering system.

[0633] In some embodiments, a heavy chain variable region of the anti-TROP2 antibody or fragment thereof comprises: (i) a HCDR1 comprising or consisting of the amino acid sequence of SEQ ID NO: 1 , or a variant thereof having up to three amino acid substitutions, additions or deletions; (ii) a HCDR2 comprising or consisting of the amino acid sequence of SEQ ID NO: 2, or a variant thereof having up to three amino acid substitutions, additions or deletions; and (iii) a HCDR3 comprising or consisting of the amino acid sequence of SEQ ID NO: 3, or a variant thereof having up to three amino acid substitutions, additions or deletions; and a light chain variable region of the anti-TROP2 antibody or fragment thereof comprises: (i) a LCDR1 comprising or consisting of the amino acid sequence of SEQ ID NO: 4, or a variant thereof having up to three amino acid substitutions, additions or deletions; (ii) a LCDR2 comprising or consisting of the amino acid sequence of SEQ ID NO: 5, or a variant thereof having up to three amino acid substitutions, additions or deletions; and (iii) a LCDR3 comprising or consisting of the amino acid sequence of SEQ ID NO: 6, or a variant thereof having up to three amino acid substitutions, additions or deletions, wherein the CDRs are defined according to the Kabat numbering system.

[0634] In some embodiments, a heavy chain variable region of the anti-TROP2 antibody or fragment thereof comprises: (i) a HCDR1 comprising or consisting of the amino acid sequence of SEQ ID NO: 7, or a variant thereof having up to three amino acid substitutions, additions or deletions; (ii) a HCDR2 comprising or consisting of the amino acid sequence ofSEQ ID NO: 8, or a variant thereof having up to three amino acid substitutions, additions or deletions; and (iii) a HCDR3 comprising or consisting of the amino acid sequence of SEQ ID NO: 9, or a variant thereof having up to three amino acid substitutions, additions or deletions, wherein the CDRs are defined according to the IMGT numbering system.

[0635] In some embodiments, a light chain variable region of the anti-TROP2 antibody or fragment thereof comprises: (i) a LCDR1 comprising or consisting of the amino acid sequence of SEQ ID NO: 10, or a variant thereof having up to three amino acid substitutions, additions or deletions; (ii) a LCDR2 comprising or consisting of the amino acid sequence of SEQ ID NO: 11 ; and (iii) a LCDR3 comprising or consisting of the amino acid sequence of SEQ ID NO: 12, or a variant thereof having up to three amino acid substitutions, additions or deletions, wherein the CDRs are defined according to the IMGT numbering system.

[0636] In some embodiments, a heavy chain variable region of the anti-TROP2 antibody or fragment thereof comprises: (i) a HCDR1 comprising or consisting of the amino acid sequence of SEQ ID NO: 7, or a variant thereof having up to three amino acid substitutions, additions or deletions; (ii) a HCDR2 comprising or consisting of the amino acid sequence of SEQ ID NO: 8, or a variant thereof having up to three amino acid substitutions, additions or deletions; and (iii) a HCDR3 comprising or consisting of the amino acid sequence of SEQ ID NO: 9, or a variant thereof having up to three amino acid substitutions, additions or deletions; and a light chain variable region of the anti-TROP2 antibody or fragment thereof comprises: (i) a LCDR1 comprising or consisting of the amino acid sequence of SEQ ID NO: 10, or a variant thereof having up to three amino acid substitutions, additions or deletions; (ii) a LCDR2 comprising or consisting of the amino acid sequence of SEQ ID NO: 11 , or a variant thereof having up to three amino acid substitutions, additions or deletions; and (iii) a LCDR3 comprising or consisting of the amino acid sequence of SEQ ID NO: 12, or a variant thereof having up to three amino acid substitutions, additions or deletions, wherein the CDRs are defined according to the IMGT numbering system.

[0637] In some embodiments, the CDR variants have up to two amino acid substitutions, additions or deletions. In some embodiments, the CDR variants have up to one amino acid substitution, addition or deletion. In some embodiments, the CDR variants have up to three amino acid substitutions. In some embodiments, the CDR variants have up to two amino acid substitutions. In some embodiments, the CDR variants have up to one amino acid substitution.

[0638] In some embodiments, a heavy chain variable region of the anti-TROP2 antibody or fragment thereof comprises or consists of the amino acid sequence of SEQ ID NO: 13, or an amino acid sequence having at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% identitythereto and / or one or more (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10) amino acid additions, deletions and / or substitutions in a framework region thereof. In some embodiments, a heavy chain variable region of the anti-TROP2 antibody or fragment thereof comprises or consists of the amino acid sequence of SEQ ID NO: 13.

[0639] In some embodiments, a light chain variable region of the anti-TROP2 antibody or fragment thereof comprises or consists of the amino acid sequence of SEQ ID NO: 14 or an amino acid sequence having at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% identity thereto and / or one or more (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10) amino acid additions, deletions and / or substitutions in a framework region thereof. In some embodiments, a light chain variable region of the anti-TROP2 antibody or fragment thereof comprises or consists of the amino acid sequence of SEQ ID NO: 14.

[0640] In some embodiments, a heavy chain variable region of the anti-TROP2 antibody or fragment thereof comprises or consists of the amino acid sequence of SEQ ID NO: 13, or an amino acid sequence having at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% identity thereto and / or one or more (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10) amino acid additions, deletions and / or substitutions in a framework region thereof; and a light chain variable region of the anti-TROP2 antibody or fragment thereof comprises or consists of the amino acid sequence of SEQ ID NO: 14 or an amino acid sequence having at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% identity thereto and / or one or more (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10) amino acid additions, deletions and / or substitutions in a framework region thereof. In some embodiments, a heavy chain variable region of the anti-TROP2 antibody or fragment thereof comprises or consists of the amino acid sequence of SEQ ID NO: 13, or an amino acid sequence having at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% identity thereto and / or one or more (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10) amino acid additions, deletions and / or substitutions in a framework region thereof, wherein the heavy chain variable region comprises: a HCDR1 comprising or consisting of the amino acid sequence of SEQ ID NO: 1; a HCDR2 comprising or consisting of the amino acid sequence of SEQ ID NO: 2; and a HCDR3 comprising or consisting of the amino acid sequence of SEQ ID NO: 3; and a light chain variable region of the anti-TROP2 antibody or fragment thereof comprises or consists of the amino acid sequence of SEQ ID NO: 14 or an amino acid sequence having at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% identity thereto and / or one or more (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10) amino acid additions, deletions and / or substitutions in a framework region thereof, wherein the light chain variable region comprises: a LCDR1 comprising or consisting of the amino acid sequence of SEQ ID NO: 4; a LCDR2 comprisingor consisting of the amino acid sequence of SEQ ID NO: 5; and a LCDR3 comprising or consisting of the amino acid sequence of SEQ ID NO: 6.

[0641] In some embodiments, a heavy chain variable region of the anti-TROP2 antibody or fragment thereof comprises or consists of the amino acid sequence of SEQ ID NO: 13, or an amino acid sequence having at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% identity thereto and / or one or more (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10) amino acid additions, deletions and / or substitutions in a framework region thereof, wherein the heavy chain variable region comprises: a HCDR1 comprising or consisting of the amino acid sequence of SEQ ID NO: 7; a HCDR2 comprising or consisting of the amino acid sequence of SEQ ID NO: 8; and a HCDR3 comprising or consisting of the amino acid sequence of SEQ ID NO: 9; and a light chain variable region of the anti-TROP2 antibody or fragment thereof comprises or consists of the amino acid sequence of SEQ ID NO: 14 or an amino acid sequence having at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% identity thereto and / or one or more (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10) amino acid additions, deletions and / or substitutions in a framework region thereof, wherein the light chain variable region comprises: a LCDR1 comprising or consisting of the amino acid sequence of SEQ ID NO: 10; a LCDR2 comprising or consisting of the amino acid sequence of SEQ ID NO: 11 ; and a LCDR3 comprising or consisting of the amino acid sequence of SEQ ID NO: 12.

[0642] In some embodiments, a heavy chain variable region of the anti-TROP2 antibody or fragment thereof comprises or consists of the amino acid sequence of SEQ ID NO: 13; and a light chain variable region of the anti-TROP2 antibody or fragment thereof comprises or consists of the amino acid sequence of SEQ ID NO: 14. In some embodiments, a heavy chain variable region of the anti-TROP2 antibody or fragment thereof consists of the amino acid sequence of SEQ ID NO: 13; and a light chain variable region of the anti-TROP2 antibody or fragment thereof consists of the amino acid sequence of SEQ ID NO: 14.

[0643] In some embodiments, a heavy chain of the anti-TROP2 antibody or fragment thereof comprises or consists of the amino acid sequence of SEQ ID NO: 15, or an amino acid sequence having at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% identity thereto and / or one or more (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10) amino acid additions, deletions and / or substitutions in a framework region thereof. In some embodiments, a heavy chain of the anti-TROP2 antibody or fragment thereof comprises or consists of the amino acid sequence of SEQ ID NO: 15.

[0644] In some embodiments, a light chain of the anti-TROP2 antibody or fragment thereof comprises or consists of the amino acid sequence of SEQ ID NO: 16 or an amino acid sequence having at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% identity theretoand / or one or more (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10) amino acid additions, deletions and / or substitutions in a framework region thereof. In some embodiments, a light chain of the anti-TROP2 antibody or fragment thereof comprises or consists of the amino acid sequence of SEQ ID NO: 16.

[0645] In some embodiments, a heavy chain of the anti-TROP2 antibody or fragment thereof comprises or consists of the amino acid sequence of SEQ ID NO: 15, or an amino acid sequence having at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% identity thereto and / or one or more (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10) amino acid additions, deletions and / or substitutions in a framework region thereof; and a light chain of the anti-TROP2 antibody or fragment thereof comprises or consists of the amino acid sequence of SEQ ID NO: 16 or an amino acid sequence having at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% identity thereto and / or one or more (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10) amino acid additions, deletions and / or substitutions in a framework region thereof.

[0646] In some embodiments, a heavy chain of the anti-TROP2 antibody or fragment thereof comprises or consists of the amino acid sequence of SEQ ID NO: 15, or an amino acid sequence having at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% identity thereto and / or one or more (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10) amino acid additions, deletions and / or substitutions in a framework region thereof, wherein the heavy chain variable region comprises: a HCDR1 comprising or consisting of the amino acid sequence of SEQ ID NO: 1; a HCDR2 comprising or consisting of the amino acid sequence of SEQ ID NO: 2; and a HCDR3 comprising or consisting of the amino acid sequence of SEQ ID NO: 3; and a light chain of the anti-TROP2 antibody or fragment thereof comprises or consists of the amino acid sequence of SEQ ID NO: 16 or an amino acid sequence having at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% identity thereto and / or one or more (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10) amino acid additions, deletions and / or substitutions in a framework region thereof, wherein the light chain variable region comprises: a LCDR1 comprising or consisting of the amino acid sequence of SEQ ID NO: 4; a LCDR2 comprising or consisting of the amino acid sequence of SEQ ID NO: 5; and a LCDR3 comprising or consisting of the amino acid sequence of SEQ ID NO: 6.

[0647] In some embodiments, a heavy chain of the anti-TROP2 antibody or fragment thereof comprises or consists of the amino acid sequence of SEQ ID NO: 15, or an amino acid sequence having at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% identity thereto and / or one or more (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10) amino acid additions, deletions and / or substitutions in a framework region thereof, wherein the heavy chain variable region comprises: a HCDR1 comprising or consisting of the amino acid sequence of SEQ ID NO: 7;a HCDR2 comprising or consisting of the amino acid sequence of SEQ ID NO: 8; and a HCDR3 comprising or consisting of the amino acid sequence of SEQ ID NO: 9; and a light chain of the anti-TROP2 antibody or fragment thereof comprises or consists of the amino acid sequence of SEQ ID NO: 16 or an amino acid sequence having at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% identity thereto and / or one or more (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10) amino acid additions, deletions and / or substitutions in a framework region thereof, wherein the light chain variable region comprises: a LCDR1 comprising or consisting of the amino acid sequence of SEQ ID NO: 10; a LCDR2 comprising or consisting of the amino acid sequence of SEQ ID NO: 11 ; and a LCDR3 comprising or consisting of the amino acid sequence of SEQ ID NO: 12.

[0648] In some embodiments, a heavy chain of the anti-TROP2 antibody or fragment thereof comprises or consists of the amino acid sequence of SEQ ID NO: 15; and a light chain of the anti-TROP2 antibody or fragment thereof comprises or consists of the amino acid sequence of SEQ ID NO: 16. In some embodiments, a heavy chain of the anti-TROP2 antibody or fragment thereof consists of the amino acid sequence of SEQ ID NO: 15; and a light chain of the anti-TROP2 antibody or fragment thereof consists of the amino acid sequence of SEQ ID NO: 16.

[0649] In some embodiments, the anti-TROP2 antibody or fragment thereof comprises or consists of two heavy chains comprising or consisting of the amino acid sequence of SEQ ID NO: 15; and two light chain comprising or consisting of the amino acid sequence of SEQ ID NO: 16. In some embodiments, the anti-TROP2 antibody or fragment thereof comprises or consists of two heavy chains consisting of the amino acid sequence of SEQ ID NO: 15; and two light chains consisting of the amino acid sequence of SEQ ID NO: 16.

[0650] In some embodiments, the anti-TROP2 antibody or fragment thereof is sacituzumab or a fragment thereof. In some embodiments, the anti-TROP2 antibody or fragment thereof is sacituzumab.

[0651] Anti-HER2 antibodies and fragments thereof

[0652] In some embodiments, the target expressed on the surface of a tumour cell is HER2. HER2 is a protein that in humans is encoded by the ERBB2 gene and which may also be known as human epidermal growth factor receptor 2 (HER-2), Receptor tyrosine-protein kinase erbB-2 and CD340 (Cluster of Differentiation 340).

[0653] In some embodiments, the antibody-drug conjugate comprises an anti-HER2 antibody or fragment thereof.In some embodiments the antibody-drug conjugate comprises an anti-HER2 antibody or a fragment thereof that binds, such as specifically binds, HER2.

[0654] The anti-HER2 antibody or fragment thereof may specifically bind HER2. The anti-HER2 antibody may be a monoclonal antibody. In some embodiments, the anti-HER2 antibody or fragment thereof is a humanized antibody. In some embodiments, the anti-HER2 antibody or fragment thereof is a monoclonal humanized antibody. The anti-HER2 antibody or fragment thereof may be a bispecific antibody. The fragment thereof may be any antigen-binding fragment thereof, for example a Fab, a Fab', a F(ab')2, a Fv, an ScFv, a Fab'-SH, an sdAb, or a VHH. In some embodiments, the anti-HER2 antibody or fragment thereof is a full-length anti-HER2 antibody. In some embodiments the antibody or antigen-binding fragment thereof comprises a VHH coupled to an Fc region.

[0655] The anti-HER2 antibody or fragment thereof may comprise a variable region that specifically binds HER2. In some embodiments, the anti-HER2 antibody or fragment thereof comprises a heavy chain variable region and / or a light chain variable domain. In some embodiments, the anti-HER2 antibody or fragment thereof comprises a heavy chain variable region and a light chain variable domain. In some embodiments, the anti-HER2 antibody or fragment thereof comprises a constant region, preferably derived from a human antibody, preferably the constant region is selected from the constant region of human lgG1, lgG2, lgG3 or lgG4. In some embodiments, the anti-HER2 antibody or fragment thereof comprises a heavy chain and / or a light chain. In some embodiments, the anti-HER2 antibody or fragment thereof comprises a heavy chain and a light chain. In some embodiments, the anti-HER2 antibody or fragment thereof comprises or consists of two heavy chains and two light chains.

[0656] Example anti-HER2 antibody CDRs, variable region sequences, and heavy and light chain sequences are provided below.

[0657] Example anti-HER2 antibody sequences - Trastuzumab

[0658]

[0659]

[0660] In some embodiments, a heavy chain variable region of the anti-HER2 antibody or fragment thereof comprises: (i) a HCDR1 comprising or consisting of the amino acid sequence of SEQ ID NO: 17, or a variant thereof having up to three amino acid substitutions, additions or deletions; (ii) a HCDR2 comprising or consisting of the amino acid sequence of SEQ ID NO: 18, or a variant thereof having up to three amino acid substitutions, additions or deletions; and (iii) a HCDR3 comprising or consisting of the amino acid sequence of SEQ ID NO: 19, or a variant thereof having up to three amino acid substitutions, additions or deletions, wherein the CDRs are defined according to the Kabat numbering system.

[0661] In some embodiments, a light chain variable region of the anti-HER2 antibody or fragment thereof comprises: (i) a LCDR1 comprising or consisting of the amino acid sequence of SEQ ID NO: 20, or a variant thereof having up to three amino acid substitutions, additions or deletions; (ii) a LCDR2 comprising or consisting of the amino acid sequence of SEQ ID NO: 21 , or a variant thereof having up to three amino acid substitutions, additions or deletions; and (iii) a LCDR3 comprising or consisting of the amino acid sequence of SEQ ID NO: 22, or a variant thereof having up to three amino acid substitutions, additions or deletions, wherein the CDRs are defined according to the Kabat numbering system.

[0662] In some embodiments, a heavy chain variable region of the anti-HER2 antibody or fragment thereof comprises: (i) a HCDR1 comprising or consisting of the amino acid sequence of SEQ ID NO: 17, or a variant thereof having up to three amino acid substitutions, additions or deletions; (ii) a HCDR2 comprising or consisting of the amino acid sequence of SEQ ID NO:18, or a variant thereof having up to three amino acid substitutions, additions or deletions; and (iii) a HCDR3 comprising or consisting of the amino acid sequence of SEQ ID NO: 19, or a variant thereof having up to three amino acid substitutions, additions or deletions; and a light chain variable region of the anti-HER2 antibody or fragment thereof comprises: (i) a LCDR1 comprising or consisting of the amino acid sequence of SEQ ID NO: 20, or a variant thereof having up to three amino acid substitutions, additions or deletions; (ii) a LCDR2 comprising or consisting of the amino acid sequence of SEQ ID NO: 21 , or a variant thereof having up to three amino acid substitutions, additions or deletions; and (iii) a LCDR3 comprising or consisting of the amino acid sequence of SEQ ID NO: 22, or a variant thereof having up to three amino acid substitutions, additions or deletions, wherein the CDRs are defined according to the Kabat numbering system.

[0663] In some embodiments, a heavy chain variable region of the anti-HER2 antibody or fragment thereof comprises: (i) a HCDR1 comprising or consisting of the amino acid sequence of SEQ ID NO: 23, or a variant thereof having up to three amino acid substitutions, additions or deletions; (ii) a HCDR2 comprising or consisting of the amino acid sequence of SEQ ID NO: 24, or a variant thereof having up to three amino acid substitutions, additions or deletions; and (iii) a HCDR3 comprising or consisting of the amino acid sequence of SEQ ID NO: 25, or a variant thereof having up to three amino acid substitutions, additions or deletions, wherein the CDRs are defined according to the IMGT numbering system.

[0664] In some embodiments, a light chain variable region of the anti-HER2 antibody or fragment thereof comprises: (i) a LCDR1 comprising or consisting of the amino acid sequence of SEQ ID NO: 26, or a variant thereof having up to three amino acid substitutions, additions or deletions; (ii) a LCDR2 comprising or consisting of the amino acid sequence of SEQ ID NO: 27; and (iii) a LCDR3 comprising or consisting of the amino acid sequence of SEQ ID NO: 28, or a variant thereof having up to three amino acid substitutions, additions or deletions, wherein the CDRs are defined according to the IMGT numbering system.

[0665] In some embodiments, a heavy chain variable region of the anti-HER2 antibody or fragment thereof comprises: (i) a HCDR1 comprising or consisting of the amino acid sequence of SEQ ID NO: 23, or a variant thereof having up to three amino acid substitutions, additions or deletions; (ii) a HCDR2 comprising or consisting of the amino acid sequence of SEQ ID NO: 24, or a variant thereof having up to three amino acid substitutions, additions or deletions; and (iii) a HCDR3 comprising or consisting of the amino acid sequence of SEQ ID NO: 25, or a variant thereof having up to three amino acid substitutions, additions or deletions; and a light chain variable region of the anti-HER2 antibody or fragment thereof comprises: (i) a LCDR1 comprising or consisting of the amino acid sequence of SEQ ID NO: 26, or a variantthereof having up to three amino acid substitutions, additions or deletions; (ii) a LCDR2 comprising or consisting of the amino acid sequence of SEQ ID NO: 27, or a variant thereof having up to three amino acid substitutions, additions or deletions; and (iii) a LCDR3 comprising or consisting of the amino acid sequence of SEQ ID NO: 28, or a variant thereof having up to three amino acid substitutions, additions or deletions, wherein the CDRs are defined according to the IMGT numbering system.

[0666] In some embodiments, the CDR variants have up to two amino acid substitutions, additions or deletions. In some embodiments, the CDR variants have up to one amino acid substitution, addition or deletion. In some embodiments, the CDR variants have up to three amino acid substitutions. In some embodiments, the CDR variants have up to two amino acid substitutions. In some embodiments, the CDR variants have up to one amino acid substitution.

[0667] In some embodiments, a heavy chain variable region of the anti-HER2 antibody or fragment thereof comprises or consists of the amino acid sequence of SEQ ID NO: 29, or an amino acid sequence having at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% identity thereto and / or one or more (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10) amino acid additions, deletions and / or substitutions in a framework region thereof. In some embodiments, a heavy chain variable region of the anti-HER2 antibody or fragment thereof comprises or consists of the amino acid sequence of SEQ ID NO: 29.

[0668] In some embodiments, a light chain variable region of the anti-HER2 antibody or fragment thereof comprises or consists of the amino acid sequence of SEQ ID NO: 30 or an amino acid sequence having at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% identity thereto and / or one or more (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10) amino acid additions, deletions and / or substitutions in a framework region thereof. In some embodiments, a light chain variable region of the anti-HER2 antibody or fragment thereof comprises or consists of the amino acid sequence of SEQ ID NO: 30.

[0669] In some embodiments, a heavy chain variable region of the anti-HER2 antibody or fragment thereof comprises or consists of the amino acid sequence of SEQ ID NO: 29, or an amino acid sequence having at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% identity thereto and / or one or more (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10) amino acid additions, deletions and / or substitutions in a framework region thereof; and a light chain variable region of the anti-HER2 antibody or fragment thereof comprises or consists of the amino acid sequence of SEQ ID NO: 30 or an amino acid sequence having at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% identity thereto and / or one or more (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10) amino acid additions, deletions and / or substitutions in a framework region thereof.In some embodiments, a heavy chain variable region of the anti-HER2 antibody or fragment thereof comprises or consists of the amino acid sequence of SEQ ID NO: 29, or an amino acid sequence having at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% identity thereto and / or one or more (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10) amino acid additions, deletions and / or substitutions in a framework region thereof, wherein the heavy chain variable region comprises: a HCDR1 comprising or consisting of the amino acid sequence of SEQ ID NO: 17; a HCDR2 comprising or consisting of the amino acid sequence of SEQ ID NO: 18; and a HCDR3 comprising or consisting of the amino acid sequence of SEQ ID NO: 19; and a light chain variable region of the anti-HER2 antibody or fragment thereof comprises or consists of the amino acid sequence of SEQ ID NO: 30 or an amino acid sequence having at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% identity thereto and / or one or more (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10) amino acid additions, deletions and / or substitutions in a framework region thereof, wherein the light chain variable region comprises: a LCDR1 comprising or consisting of the amino acid sequence of SEQ ID NO: 20; a LCDR2 comprising or consisting of the amino acid sequence of SEQ ID NO: 21; and a LCDR3 comprising or consisting of the amino acid sequence of SEQ ID NO: 22.

[0670] In some embodiments, a heavy chain variable region of the anti-HER2 antibody or fragment thereof comprises or consists of the amino acid sequence of SEQ ID NO: 29, or an amino acid sequence having at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% identity thereto and / or one or more (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10) amino acid additions, deletions and / or substitutions in a framework region thereof, wherein the heavy chain variable region comprises: a HCDR1 comprising or consisting of the amino acid sequence of SEQ ID NO: 23; a HCDR2 comprising or consisting of the amino acid sequence of SEQ ID NO: 24; and a HCDR3 comprising or consisting of the amino acid sequence of SEQ ID NO: 25; and a light chain variable region of the anti-HER2 antibody or fragment thereof comprises or consists of the amino acid sequence of SEQ ID NO: 30 or an amino acid sequence having at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% identity thereto and / or one or more (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10) amino acid additions, deletions and / or substitutions in a framework region thereof, wherein the light chain variable region comprises: a LCDR1 comprising or consisting of the amino acid sequence of SEQ ID NO: 26; a LCDR2 comprising or consisting of the amino acid sequence of SEQ ID NO: 27; and a LCDR3 comprising or consisting of the amino acid sequence of SEQ ID NO: 28.

[0671] In some embodiments, a heavy chain variable region of the anti-HER2 antibody or fragment thereof comprises or consists of the amino acid sequence of SEQ ID NO: 29; and a light chain variable region of the anti-HER2 antibody or fragment thereof comprises or consists of the amino acid sequence of SEQ ID NO: 30. In some embodiments, a heavy chain variableregion of the anti-HER2 antibody or fragment thereof consists of the amino acid sequence of SEQ ID NO: 29; and a light chain variable region of the anti-HER2 antibody or fragment thereof consists of the amino acid sequence of SEQ ID NO: 30.

[0672] In some embodiments, a heavy chain of the anti-HER2 antibody or fragment thereof comprises or consists of the amino acid sequence of SEQ ID NO: 31 , or an amino acid sequence having at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% identity thereto and / or one or more (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10) amino acid additions, deletions and / or substitutions in a framework region thereof. In some embodiments, a heavy chain of the anti-HER2 antibody or fragment thereof comprises or consists of the amino acid sequence of SEQ ID NO: 31.

[0673] In some embodiments, a light chain of the anti-HER2 antibody or fragment thereof comprises or consists of the amino acid sequence of SEQ ID NO: 32 or an amino acid sequence having at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% identity thereto and / or one or more (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10) amino acid additions, deletions and / or substitutions in a framework region thereof. In some embodiments, a light chain of the anti-HER2 antibody or fragment thereof comprises or consists of the amino acid sequence of SEQ ID NO: 32.

[0674] In some embodiments, a heavy chain of the anti-HER2 antibody or fragment thereof comprises or consists of the amino acid sequence of SEQ ID NO: 31 , or an amino acid sequence having at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% identity thereto and / or one or more (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10) amino acid additions, deletions and / or substitutions in a framework region thereof; and a light chain of the anti-HER2 antibody or fragment thereof comprises or consists of the amino acid sequence of SEQ ID NO: 32 or an amino acid sequence having at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% identity thereto and / or one or more (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10) amino acid additions, deletions and / or substitutions in a framework region thereof.

[0675] In some embodiments, a heavy chain of the anti-HER2 antibody or fragment thereof comprises or consists of the amino acid sequence of SEQ ID NO: 31 , or an amino acid sequence having at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% identity thereto and / or one or more (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10) amino acid additions, deletions and / or substitutions in a framework region thereof, wherein the heavy chain variable region comprises: a HCDR1 comprising or consisting of the amino acid sequence of SEQ ID NO: 17; a HCDR2 comprising or consisting of the amino acid sequence of SEQ ID NO: 18; and a HCDR3 comprising or consisting of the amino acid sequence of SEQ ID NO: 19; and a light chain of the anti-HER2 antibody or fragment thereof comprises or consists of the amino acidsequence of SEQ ID NO: 32 or an amino acid sequence having at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% identity thereto and / or one or more (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10) amino acid additions, deletions and / or substitutions in a framework region thereof, wherein the light chain variable region comprises: a LCDR1 comprising or consisting of the amino acid sequence of SEQ ID NO: 20; a LCDR2 comprising or consisting of the amino acid sequence of SEQ ID NO: 21 ; and a LCDR3 comprising or consisting of the amino acid sequence of SEQ ID NO: 22.

[0676] In some embodiments, a heavy chain of the anti-HER2 antibody or fragment thereof comprises or consists of the amino acid sequence of SEQ ID NO: 31 , or an amino acid sequence having at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% identity thereto and / or one or more (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10) amino acid additions, deletions and / or substitutions in a framework region thereof, wherein the heavy chain variable region comprises: a HCDR1 comprising or consisting of the amino acid sequence of SEQ ID NO: 23; a HCDR2 comprising or consisting of the amino acid sequence of SEQ ID NO: 24; and a HCDR3 comprising or consisting of the amino acid sequence of SEQ ID NO: 25; and a light chain of the anti-HER2 antibody or fragment thereof comprises or consists of the amino acid sequence of SEQ ID NO: 32 or an amino acid sequence having at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% identity thereto and / or one or more (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10) amino acid additions, deletions and / or substitutions in a framework region thereof, wherein the light chain variable region comprises: a LCDR1 comprising or consisting of the amino acid sequence of SEQ ID NO: 26; a LCDR2 comprising or consisting of the amino acid sequence of SEQ ID NO: 27; and a LCDR3 comprising or consisting of the amino acid sequence of SEQ ID NO: 28.

[0677] In some embodiments, a heavy chain of the anti-HER2 antibody or fragment thereof comprises or consists of the amino acid sequence of SEQ ID NO: 31 ; and a light chain of the anti-HER2 antibody or fragment thereof comprises or consists of the amino acid sequence of SEQ ID NO: 32. In some embodiments, a heavy chain of the anti-HER2 antibody or fragment thereof consists of the amino acid sequence of SEQ ID NO: 31 ; and a light chain of the anti-HER2 antibody or fragment thereof consists of the amino acid sequence of SEQ ID NO: 32.

[0678] In some embodiments, the anti-HER2 antibody or fragment thereof comprises or consists of two heavy chains comprising or consisting of the amino acid sequence of SEQ ID NO: 31; and two light chain comprising or consisting of the amino acid sequence of SEQ ID NO: 32. In some embodiments, the anti-HER2 antibody or fragment thereof comprises or consists oftwo heavy chains consisting of the amino acid sequence of SEQ ID NO: 31; and two light chains consisting of the amino acid sequence of SEQ ID NO: 32.

[0679] In some embodiments, the anti-HER2 antibody or fragment thereof is trastuzumab or a fragment thereof. In some embodiments, the anti-HER2 antibody is trastuzumab.

[0680] Anti-HER3 antibodies and fragments thereof

[0681] In some embodiments, the target expressed on the surface of a tumour cell is HER3. HER3 is a protein that in humans is encoded by the ERBB3 gene and which may also be known as human epidermal growth factor receptor 3 (HER-3) and Receptor tyrosine-protein kinase erbB-3.

[0682] In some embodiments, the antibody-drug conjugate comprises an anti-HER3 antibody or fragment thereof.

[0683] In some embodiments the antibody-drug conjugate comprises an anti-HER3 antibody or a fragment thereof that binds, such as specifically binds, HER3.

[0684] The anti-HER3 antibody or fragment thereof may specifically bind HER3. The anti-HER3 antibody or fragment thereof may block HER3 ligand-dependent and HER3 ligandindependent signalling. The anti-HER3 antibody or fragment thereof may inhibit HER3 ligand-dependent and Her3 ligand-independent AKT phosphorylation.

[0685] The anti-HER3 antibody may be a monoclonal antibody. In some embodiments, the anti-HER3 antibody or fragment thereof is a humanized antibody. In some embodiments, the anti-HER3 antibody or fragment thereof is a monoclonal humanized antibody. In some embodiments, the anti-HER3 antibody or fragment thereof is a human antibody. In some embodiments, the anti-HER3 antibody or fragment thereof is a monoclonal human antibody. The anti-HER3 antibody or fragment thereof may be a bispecific antibody. The fragment thereof may be any antigen-binding fragment thereof, for example a Fab, a Fab', a F(ab')2, a Fv, a scFv, a Fab'-SH, an sdAb, or a VHH. In some embodiments, the anti-HER3 antibody or fragment thereof is a full-length anti-HER3 antibody.

[0686] In some embodiments the antibody or antigen-binding fragment thereof comprises a VHH coupled to an Fc region.

[0687] The anti-HER3 antibody or fragment thereof may comprise a variable region that specifically binds HER3. In some embodiments, the anti-HER3 antibody or fragment thereof comprisesa heavy chain variable region and / or a light chain variable domain. In some embodiments, the anti-HER3 antibody or fragment thereof comprises a heavy chain variable region and a light chain variable domain. In some embodiments, the anti-HER3 antibody or fragment thereof comprises a constant region, preferably derived from a human antibody, preferably the constant region is selected from the constant region of human lgG1, lgG2, lgG3 or lgG4. In some embodiments, the anti-HER3 antibody or fragment thereof comprises a heavy chain and / or a light chain. In some embodiments, the anti-HER3 antibody or fragment thereof comprises a heavy chain and a light chain. In some embodiments, the anti-HER3 antibody or fragment thereof comprises or consists of two heavy chains and two light chains.

[0688] Binding Molecule - Linker - Payload Conjugates - Formula (III)

[0689] The binding molecule - linker-payload conjugates of the invention are compounds of formula (HI):

[0690]

[0691] or a pharmaceutically acceptable salt or solvate thereof, wherein:

[0692] BM is a binding molecule or a fragment thereof as defined herein, either in its broadest aspect or any of the preferred aspects recited herein;

[0693] X, A, Ri , R2, R3, R4 and Rs are as defined herein, either in its broadest aspect or any of the preferred aspects recited herein;

[0694] L is a linker as defined herein either in its broadest aspect or any of the preferred aspects recited herein; and

[0695] g is an integer from 1 to 16.

[0696] In one embodiment, the linker-payload conjugates of formula (III) are compounds of formula (lll-Y):

[0697]

[0698] or a pharmaceutically acceptable salt or solvate thereof,

[0699] wherein:

[0700] BM is a binding molecule or a fragment thereof;

[0701] II is O or S;

[0702] X is a bond, O, S, S(=O) or S(=O)2;

[0703] when X is O, S, S(=O) or S(=O)2, A is C2-10 alkylene, C2-10 alkenylene, C2- alkynylene, C3-10 cycloalkylene, C3-10 cycloalkenylene, Cs- cycloalkynylene, C3-10 heterocycloalkylene, C3-10 heterocycloalkenylene, or Cs- heterocycloalkynylene, each optionally substituted with one or more substituents selected from List 1 ;

[0704] when X is a bond, A is C1-10 alkylene, C2-10 alkenylene, C2- alkynylene, C3-10 cycloalkylene, C3-10 cycloalkenylene, Cs- cycloalkynylene, C3-10 heterocycloalkylene, C3-10 heterocycloalkenylene, or Cs- heterocycloalkynylene, each optionally substituted with one or more substituents selected from List 1 ;

[0705] R1 and R4 are each independently H, C1-6 alkyl, or C3-10 cycloalkyl, or R1 and R4 together with the carbon atoms to which they are attached form a 5- to 7-membered carbocyclic ring which is substituted by a group -NH-C(=O)-Rs;

[0706] R2 is H, halogen or C1-6 alkyl;

[0707] R3 is C1-6 alkyl; and

[0708] Rs is C1-6 alkyl or-NR’R”, wherein R’ and R” are each independently H or C1-6 alkyl;

[0709] L is a linker of formula (LX”):

[0710]

[0711] wherein:

[0712] R is C1-6 alkyl;

[0713] EO is an ethylene glycol moiety, the terminal carbon of which is attached to the group -N(R)-and the terminal oxygen of which is attached to the group -(CH2)W- when w is 1 to 10, or to the - C(=O) group when w is 0;

[0714] v is 0 or 1 to 40;

[0715] w is 0 or 1 to 10;

[0716] P is a peptide moiety consisting of 1 to 10 amino acid residues;

[0717] Re and R? are each independently H or C1-6 alkyl, or Re and R? together with the carbon atom to which they are attached form a 3- to 10-membered carbocyclic ring;

[0718] position (1) is bonded to the connecting atom on the binding molecule BM;

[0719] position (2) is bonded to the II atom of the -L-U- moiety; and

[0720] q is an integer from 1 to 16.

[0721] In the embodiment wherein R1 and R4 together with the carbon atoms to which they are attached form a 5- to 7-membered carbocyclic ring which is substituted by a group -NH-C(=O)-Rs, the compounds are of formula (IIIA):

[0722]

[0723] wherein BM, II, L, X, A, R2, R3, and Rs have the meanings defined herein, either in the broadest aspect of any of the preferred aspects recited herein;

[0724] n is 0, 1 , or 2; and m is 0, 1 or 2, with the proviso that m+n must be 1 , 2 or 3. In one embodiment, n is 0. In one embodiment, n is 1. In one embodiment, n is 2.

[0725] In one embodiment, m is 2. In one embodiment, m is 1. In one embodiment, m is 2.In one embodiment, the binding molecule - linker-payload of the invention is a compound of formula (lll-YY):

[0726] <

[0727]

[0728] (lll-YY)

[0729] or a pharmaceutically acceptable salt or solvate thereof,

[0730] wherein:

[0731] BM is a binding molecule or a fragment thereof;

[0732] X, A, Ri, R2, R3, R4 and Rs are as defined herein for formula (ll-YY);

[0733] L is a linker as defined herein either in its broadest aspect or any of the preferred aspects recited herein; and

[0734] q is an integer from 1 to 16.

[0735] In one embodiment, the linker-payload conjugates of formula (III) are compounds of formula (lll-B):

[0736] ""

[0737]

[0738] or a pharmaceutically acceptable salt or solvate thereof,

[0739] wherein:

[0740] BM is a binding molecule or a fragment thereof;

[0741] L, II, A, X and R1-R4 are as defined above for formula (I l-B); and

[0742] q is an integer from 1 to 16.

[0743] In one embodiment, the linker-payload conjugates of formula (III) are compounds of formula (lll-C):

[0744]

[0745] or a pharmaceutically acceptable salt or solvate thereof,

[0746] wherein:

[0747] BM is a binding molecule or a fragment thereof;

[0748] L, II, A, X and R1-R4 are as defined above for formula (I l-C); and

[0749] q is an integer from 1 to 16.

[0750] In one embodiment, the linker-payload conjugates of formula (III) are compounds of formula (lll-D):

[0751]

[0752] or a pharmaceutically acceptable salt or solvate thereof,

[0753] wherein:

[0754] BM is a binding molecule or a fragment thereof;

[0755] L, II, A, X and R1-R4 are as defined above for formula (I l-D); and

[0756] q is an integer from 1 to 16.

[0757] In the binding molecule-linker-payload conjugates of formula (III) of the present invention, including those of formula (IIIA), (lll-B), (lll-C), (lll-D), (lll-YY) and (lll-Y), as defined above, the variables X, II, A, R1, R2, R3, R4 and Rs may take any of the meanings defined above for these substituents, either in the broadest embodiments or any of the narrower embodiments defined herein.

[0758] In the binding molecule-linker-payload conjugates of formula (III) of the present invention, including those of formula (IIIA), (lll-B), (lll-C), (Ill-D) and (lll-YY), the linker L may take any of the meanings as defined herein, either in the broadest embodiment or any of the narrower embodiments defined herein.

[0759] In one embodiment of the binding molecule-linker-payload conjugates of formula (III) of the present invention, including those of formula (IIIA), (lll-B), (lll-C), (Ill-D) and (lll-YY), the linker L is of the formula (LX) or (LX”) as defined herein, either in the broadest embodiment or any of the narrower embodiments defined herein.

[0760] In one embodiment of the binding molecule-linker-payload conjugates of formula (III) of the present invention, including those of formula (IIIA), (lll-B), (lll-C), (Ill-D), (lll-YY) and (lll-Y), the linker L is of the formula (L1) as defined herein.In one embodiment of the binding molecule-linker-payload conjugates of formula (III) of the present invention, including those of formula (IIIA), (lll-B), (lll-C), (lll-D), (lll-YY) and (lll-Y), the linker L is of the formula (L2) as defined herein.

[0761] In one embodiment of the binding molecule-linker-payload conjugates of formula (III) of the present invention, including those of formula (IIIA), (lll-B), (lll-C), (lll-D), (lll-YY) and (lll-Y), the linker L is of the formula (L3) as defined herein.

[0762] In one embodiment of the binding molecule-linker-payload conjugates of formula (III) of the present invention, including those of formula (IIIA), (lll-B), (lll-C), (lll-D), (lll-YY) and (lll-Y), the linker L is of the formula (L4) as defined herein.

[0763] In one embodiment of the binding molecule-linker-payload conjugates of formula (III) of the present invention, including those of formula (IIIA), (lll-B), (lll-C), (lll-D), (lll-YY) and (lll-Y), the linker L is of the formula (L5) as defined herein.

[0764] In compounds of formula (III), including compounds of formula (IIIA), (lll-B), (lll-C), (lll-D), (lll-YY) and (lll-Y), the binding molecule-drug ratio q is an integer. The ratio q is the number of linker-payload molecules attached to each binding molecule antibody or fragment thereof. As indicated above binding molecule-drug ratio q of the binding molecule-linker-payload conjugates used in the invention may vary. When the binding molecule is an antibody or a fragment thereof, the value q may also be termed a “drug-antibody ratio” (DAR).

[0765] In some embodiments, q is an integer from 1 to 16. In some embodiments, q is an integer of 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 or 16. In some embodiments, q is an integer from 4 to 12. In some embodiments, q is an integer from 4 to 12. In some embodiments, q is an integer from 6 to 10. In some embodiments, q is an integer from 5 to 9. In some embodiments, q is an integer from 4 to 8. In some embodiments, q is 4. In some embodiments, q is 5. In some embodiments, q is 6. In some embodiments, q is 7. In some embodiments, q is 8.

[0766] In one embodiment, the compound of formula (III) is a compound of formula 111-1 through HI-15, as shown in Table 3 below, or a pharmaceutically acceptable salt or solvate thereof:

[0767] >

[0768] >

[0769] >

[0770]

[0771] "

[0772] <

[0773] " >

[0774]

[0775] Table 3Compositions comprising Binding Molecule- Drug Conjugates - Formula dll’)

[0776] In contrast to the compounds of formula (III) above, in the compositions of the present invention of formula (III’) which may contain multiple compounds of formula (III) with different values of the binding molecule-drug ratio g’, the average binding molecule-drug ratio g’ may be non-integral. When the binding molecule is an antibody or a fragment thereof, the value g’ may also be termed an average antibody-drug ratio (DAR).

[0777] Therefore, there is also provided a composition comprising a compound of formula (III’):

[0778]

[0779] or a pharmaceutically acceptable salt thereof, wherein:

[0780] BM is a binding molecule or a fragment thereof, either in its broadest aspect or any of the preferred aspects recited herein;

[0781] X, II, A, Ri, R2, 3, 4 and Rs are as defined herein, either in its broadest aspect or any of the preferred aspects recited herein;

[0782] L is a linker as defined herein, either in its broadest aspect or any of the preferred aspects recited herein; and

[0783] g’ is an integer or a decimal from 1 to 16.

[0784] In one embodiment, the linker-payload conjugates of formula (III’) are compounds of formula (lll-Y’):

[0785]

[0786] or a pharmaceutically acceptable salt or solvate thereof,

[0787] wherein:

[0788] BM is a binding molecule or a fragment thereof;

[0789] II is O or S;

[0790] X is a bond, O, S, S(=O) or S(=O)2;

[0791] when X is O, S, S(=O) or S(=O)2, A is C2-10 alkylene, C2-10 alkenylene, C2- alkynylene, C3-10 cycloalkylene, C3-10 cycloalkenylene, Cs- cycloalkynylene, C3-10 heterocycloalkylene, C3-10 heterocycloalkenylene, or Cs- heterocycloalkynylene, each optionally substituted with one or more substituents selected from List 1 ;

[0792] when X is a bond, A is C1-10 alkylene, C2-10 alkenylene, C2- alkynylene, C3-10 cycloalkylene, C3-10 cycloalkenylene, Cs- cycloalkynylene, C3-10 heterocycloalkylene, C3-10 heterocycloalkenylene, or Cs- heterocycloalkynylene, each optionally substituted with one or more substituents selected from List 1 ;

[0793] R1 and R4 are each independently H, C1-6 alkyl, or C3-10 cycloalkyl, or R1 and R4 together with the carbon atoms to which they are attached form a 5- to 7-membered carbocyclic ring which is substituted by a group -NH-C(=O)-Rs;

[0794] R2 is H, halogen or C1-6 alkyl;

[0795] R3 is C1-6 alkyl; and

[0796] Rs is C1-6 alkyl or-NR’R”, wherein R’ and R” are each independently H or C1-6 alkyl;

[0797] L is a linker of formula (LX”):

[0798]

[0799] wherein:R is C1-6 alkyl;

[0800] EO is an ethylene glycol moiety, the terminal carbon of which is attached to the group -N(R)-and the terminal oxygen of which is attached to the group -(CH2)W- when w is 1 to 10, or to the - C(=O) group when w is 0;

[0801] v is 0 or 1 to 40;

[0802] w is 0 or 1 to 10;

[0803] P is a peptide moiety consisting of 1 to 10 amino acid residues;

[0804] Re and R? are each independently H or C1-6 alkyl, or Re and R? together with the carbon atom to which they are attached form a 3- to 10-membered carbocyclic ring;

[0805] position (1) is bonded to the connecting atom on the binding molecule BM;

[0806] position (2) is bonded to the II atom of the -L-U- moiety; and

[0807] q’ is an integer or decimal from 1 to 16.

[0808] In the embodiment wherein Ri and R4 together with the carbon atoms to which they are attached form a 5- to 7-membered carbocyclic ring which is substituted by a group -NH-C(=O)-Rs, the compositions comprise compounds are of formula (IIIA’):

[0809]

[0810] aspect of any of the preferred aspects recited herein;

[0811] n is 0, 1 , or 2; and m is 0, 1 or 2, with the proviso that m+n must be 1 , 2 or 3.

[0812] In one embodiment, n is 0. In one embodiment, n is 1. In one embodiment, n is 2. In one embodiment, m is 0. In one embodiment, m is 1. In one embodiment, m is 2.A further embodiment of the invention relates to a composition comprising a compound of formula (lll-YY’):

[0813]

[0814] (lll-YY’)

[0815] or a pharmaceutically acceptable salt or solvate thereof,

[0816] wherein:

[0817] BM is a binding molecule or a fragment thereof;

[0818] X, A, Ri, R2, R3, R4 and Rs are as defined herein for formula (ll-YY);

[0819] L is a linker as defined herein either in its broadest aspect or any of the preferred aspects recited herein; and

[0820] q’ is an integer or decimal from 1 to 16.

[0821] A further embodiment of the invention relates to a composition comprising a compound of formula (II l-B’):

[0822]

[0823] or a pharmaceutically acceptable salt or solvate thereof,

[0824] wherein:

[0825] BM is a binding molecule or a fragment thereof;

[0826] L, II, A, X and R1-R4 are as defined above for formula (I l-B); and

[0827] q’ is an integer or decimal from 1 to 16.

[0828] A further embodiment of the invention relates to a composition comprising a compound of formula (II l-C’):

[0829]

[0830] or a pharmaceutically acceptable salt or solvate thereof,

[0831] wherein:

[0832] BM is a binding molecule or a fragment thereof;

[0833] L, II, A, X and R1-R4 are as defined above for formula (I l-C); and

[0834] q’ is an integer or decimal from 1 to 16.

[0835] A further embodiment of the invention relates to a composition comprising a compound of formula (II l-D’):

[0836]

[0837] or a pharmaceutically acceptable salt or solvate thereof,

[0838] wherein:

[0839] BM is a binding molecule or a fragment thereof;

[0840] L, II, A, X and R1-R4 are as defined above for formula (I l-D); and

[0841] q’ is an integer or decimal from 1 to 16.

[0842] In some embodiments, q’ is an integer or decimal from about 1 to about 16. In some embodiments, q’ is an integer or decimal of about 1 , about 2, about 3, about 4, about 5, about 6, about?, about 8, about 9, about 10, about 11, about 12, about 13, about 14, about 15 or about 16. In some embodiments, q’ is an integer or decimal from about 4 to about 12. In some embodiments, q’ is an integer or decimal from about 4 to about 8.

[0843] In some embodiments, q’ is about 4.0. In some embodiments, q’ is about 4.1. In some embodiments, q’ is about 4.2. In some embodiments, q’ is about 4.3. In some embodiments, q’ is about 4.4. In some embodiments, q’ is about 4.5. In some embodiments, q’ is about 4.6. In some embodiments, q’ is about 4.7. In some embodiments, q’ is about 4.8. In some embodiments, q’ is about 4.9. In some embodiments, q’ is about 5.0. In some embodiments, q’ is about 5.1. In some embodiments, q’ is about 5.2. In some embodiments, q’ is about 5.3. In some embodiments, q’ is about 5.4. In some embodiments, q’ is about 5.5. In some embodiments, q’ is about 5.6. In some embodiments, q’ is about 5.7. In some embodiments, q’ is about 5.8. In some embodiments, q’ is about 5.9. In some embodiments, q’ is about 6.0. In some embodiments, q’ is about 6.1. In some embodiments, q’ is about 6.2. In some embodiments, q’ is about 6.3. In some embodiments, q’ is about 6.4. In some embodiments, q’ is about 6.5. In some embodiments, q’ is about 6.6. In some embodiments, q’ is about 6.7. In some embodiments, q’ is about 6.8. In someembodiments, q’ is about 6.9. In some embodiments, q’ is about 7.0. In some embodiments, q’ is about 7.1. In some embodiments, q’ is about 7.2. In some embodiments, q’ is about 7.3. In some embodiments, q’ is about 7.4. In some embodiments, q’ is about 7.5. In some embodiments, q’ is about 7.6. In some embodiments, q’ is about 7.7. In some embodiments, q’ is about 7.8. In some embodiments, q’ is about 7.9. In some embodiments, q’ is about 8.0.

[0844] Payload-Products of Enzymatic Hydrolysis

[0845] A further aspect of the invention relates to payload-products of the enzymatic cleavage of the linker-payloads described herein. In some embodiments, the enzymatic cleavage is by enzymatic hydrolysis.

[0846] In some embodiments, the linker group in the linker-payload has a single cleavage site for enzymatic hydrolysis. The cleavage site of the linker-payload depends on the enzyme employed for hydrolysis.

[0847] In some embodiments, the linkergroup in the linker-payload has more than one cleavage site for enzymatic hydrolysis. Where there is more than one cleavage site, enzymatic hydrolysis of the linker-payload lead may lead to a mixture of payload-products.

[0848] In some embodiments, the linker group in the linker-payload has two cleavage sites for enzymatic hydrolysis, thus two different payload products are generated.

[0849] In some embodiments, the linker group in the linker-payload has two or more cleavage sites for enzymatic hydrolysis, namely a primary cleavage site, and one or more secondary cleavage site, and cleavage preferentially takes place at the primary cleavage site over the one or more secondary cleavage sites, thereby giving rise to a major payload-product and one or more minor payload-products.

[0850] In some embodiments, the linker group in the linker-payload has two cleavage sites for enzymatic hydrolysis, namely a primary cleavage site, and a secondary cleavage site, and cleavage preferentially takes place at the primary cleavage site over the secondary cleavage site, thereby giving rise to a major payload-product and a minor payload-product.

[0851] In some embodiments, the linker-payload is susceptible to enzymatic hydrolysis with a lysosomal enzyme such as a Cathepsin. In some embodiments, the lysosomal enzyme is Cathepsin B. In some embodiments, the lysosomal enzyme is Cathepsin L.

[0852] In some embodiments, the linker is a group selected from L1, L2, L3, L4 and L5 as described herein.In some embodiments, the linkergroup is of formula L1, and the linker-payload has two cleavage sites susceptible to enzymatic hydrolysis with a lysosomal enzyme such as a Cathepsin, thereby generating two different payload-products.

[0853] In some embodiments, the linkergroup is of formula L2, and the linker-payload has one cleavage site susceptible to enzymatic hydrolysis with a lysosomal enzyme such as a Cathepsin, thereby generating a single payload-product.

[0854] In some embodiments, the linkergroup is of formula L3, and the linker-payload has a primary cleavage site and a secondary cleavage site, each of which is susceptible to enzymatic hydrolysis with a lysosomal enzyme such as a Cathepsin, thereby a generating a major payload-product and a minor payload-product.

[0855] In some embodiments, the linkergroup is of formula L4, and the linker-payload has a primary cleavage site and a secondary cleavage site, each of which is susceptible to enzymatic hydrolysis with a lysosomal enzyme such as a Cathepsin, thereby a generating a major payload-product and a minor payload-product.

[0856] In some embodiments, the linkergroup is of formula L5, and the linker-payload has a primary cleavage site and a secondary cleavage site, each of which is susceptible to enzymatic hydrolysis with a lysosomal enzyme such as a Cathepsin, thereby a generating a major payload-product and a minor payload-product.

[0857] In some embodiments, the payload-product of the enzymatic hydrolysis of the linker-payload is a compound selected from 1-1 to 1-16 as shown in Table 1 above, and pharmaceutically acceptable salts thereof.

[0858] In some embodiments, the payload-product formed on cleavage of the linker-payload retains a portion of the linker group. For example, in some embodiments, the linker-payload is cleaved such that a glycine moiety remains attached to the payload in the payload-product. In some embodiments, the payload-product of the enzymatic hydrolysis of the linker-payload is a compound selected from compounds l-T to 1-16’ shown in Table T below, and pharmaceutically acceptable salts thereof:

[0859]

[0860]

[0861]

[0862]

[0863] General Methods

[0864] The compounds of the invention may be synthesised by the methods generally described in the Schemes below.

[0865]

[0866] Scheme 1

[0867] In Scheme 1, A is alkylene where n = 1 to 10; PGi is a hydroxyl-protecting group, typically C1-6 alkyl, preferably methyl; LGi is a leaving group, preferably halogen or sulfonate, more preferably bromine, LG2 and LG3 are leaving groups as defined below, and PG2 is a hydroxyl-protecting group, preferably a silyl group, more preferably tert-butyldimethylsilyl. Compounds of formula (I’) are those of formula (I) wherein X is O, and compounds of formula (I”) are those of formula (I) wherein X is a bond.Step 1 comprises reaction of a compound of formula (IV) with a compound of formula (V) to generate a compound of formula (VI). The reaction is typically carried out in the presence of an acid catalyst or a suitable salt. In one embodiment, the acid catalyst a sulfonic acid, such as p-toluenesulfonic acid, preferably as the pyridinium salt, pyridinium p-toluenesulfonate (PPTS).

[0868] Step 2 comprises deprotection of the compound of formula (VI) to generate a compound of formula (VII). This can be carried out under suitable deprotection conditions well known to those skilled in the art. When the protecting group PGi is an alkyl group, the reaction is typically carried out in the presence of a strong acid, typically a hydrohalic acid. In one embodiment, the acid is hydrobromic acid.

[0869] Step 3 comprises reaction of a compound of formula (VII) with a compound of formula (VIII) to generate a compound of formula (I’). As part of this reaction, the protecting group PG2 of the compound of formula (VIII) is cleaved. The reaction is typically carried out in the presence of a base, typically a strong base. In one embodiment, the base is a guanidine, typically tetramethylguanidine (TMG).

[0870] Step 3’ comprises conversion of the hydroxyl group of the compound of formula (VII) into a leaving group O-LG2 to generate a compound of formula (Villa). Typically LG2 is a sulfonyl group, such as a trifluoromethylsulfonyl group.

[0871] Step 4 comprises coupling of the compound of formula (Villa) with a compound of formula LG3-(CH2)n-OPG2under aryl coupling conditions to generate a compound of formula (Vlllb). Typically LG3 is a trihaloborate such as trifluoroborate, and PG2 is a silyl group, such as a tert-butyldimethylsilyl group.

[0872] The reaction is typically carried out in the presence of a suitable aryl coupling catalyst and a base. Typical aryl coupling catalysts include palladium (II) salts such as PdCh(dppf).

[0873] Typical bases include alkali metal carbonates such as caesium carbonate.

[0874] Step 5 comprises deprotection of the compound of formula (Vlllb) to generate a compound of formula (I”). This can be carried out under suitable deprotection conditions well known to those skilled in the art. When the protecting group PG2 is a silyl group, the reaction is typically carried out in the presence of trifluoroacetic acid or a reagent that releases fluoride ions, such as tetrabutylammonium fluoride (TBAF).Method 1A. Synthesis of Payload Compounds of Formula (I)

[0875] Compounds of Formula (IA) wherein Ri and R4 together with the carbon atoms to which they are attached form a 6-membered carbocyclic ring may be made according to Scheme 1 A. In this particular example, R5 is C1-6 alkyl, II is O, and X is O (compounds of formula (IA’) or a bond (compounds of formula (IA”)), LG1 , LG2 and LG3 are leaving groups, PG1 and PG2 are protecting groups, and n is 1 to 3.

[0876]

[0877] Scheme 1AStep 1 comprises reaction of a compound of formula (IX) with an iodinating reagent under oxidising conditions to generate a compound of formula (X). Typical reagents include iodine and a periodate, such as sodium periodate.

[0878] The reaction is typically carried out in the presence of a strong acid catalyst, In one embodiment, the acid catalyst is sulphuric acid.

[0879] Step 2 comprises reaction of the compound of formula (X) with a suitable alkenoate under aryl coupling conditions to generate a compound of formula (XI). Typical reagents include tert-butyl butenoate.

[0880] The reaction is typically carried out in the presence of a suitable aryl coupling catalyst and a triaryl phosphine. Typical aryl coupling catalysts include palladium (II) salts such as palladium (II) acetate. Typical triaryl phosphines include tri(o-tolyl)phosphine.

[0881] Step 3 comprises reaction of the compound of formula (XI) to generate a compound of formula (XII). This proceeds by (a) generation of a nitroso moiety alpha to the ester; (b) reduction of the nitroso, nitro group and alkene moieties; (c) attachment of the acyl group -C(=O)Rs to the amines.

[0882] Step 3(a) is typically carried out using a strong base such as potassium tert-butoxide, and an alkyl nitrite, such as isopentyl nitrite.

[0883] Step 3(b) is typically carried out using hydrogen in the presence of a suitable hydrogenation catalyst. Typical hydrogenation catalysts include palladium on carbon.

[0884] Step 3(c) is typically carried out using an acid anhydride Rs-C(=O)-O-C(=O)-R5, typically in the presence of the corresponding acid R5-C(=O)-OH.

[0885] Step 4 comprises ring closure of the compound of formula (XII) to generate a compound of formula (XIII). Typical reagents include hydrochlorosilanes, such as chlorodimethylsilane. The reaction is typically carried out in the presence of a suitable catalyst, typically a Lewis acid catalyst such as indium (III) chloride.

[0886] Step 5 comprises selective deacylation of the anilino-amide of the compound of formula (XIII) to generate a compound of formula (XIV). Typical reagents include strong acids, such as hydrochloric acid.Step 6 comprises reaction of a compound of formula (XIV) with a compound of formula (V) to generate a compound of formula (XV). The reaction is typically carried out in the presence of an acid catalyst or suitable salt. In one embodiment, the acid catalyst is a sulfonic acid, such as p-toluenesulfonic acid, or a salt thereof, preferably the pyridinium salt, pyridinium p-toluenesulfonate (PPTS).

[0887] Step 7 comprises cleavage of the methyl ether bond of the compound of formula (XV) to generate a compound of formula (XVI). Typical reagents include strong acids, such as hydrobromic acid.

[0888] Step 8 comprises alkylation of the compound of formula (XVI) with a compound of formula LGi-CH2-(CH2)n-OPGi to generate a compound of formula (XVII). Typically LGi is a halogen atom, such as bromo, and PGi is a silyl group, such as a tert-butyldimethylsilyl group.

[0889] Step 9 comprises deprotection of the compound of formula (XVII) to generate a compound of formula (IA’). This can be carried out under suitable deprotection conditions well known to those skilled in the art. When the protecting group PGi is a silyl group, the reaction is typically carried out in the presence of trifluoroacetic acid or a reagent that releases fluoride ions, such as tetrabutylammonium fluoride (TBAF).

[0890] Step 10 comprises conversion of the hydroxyl group of the compound of formula (XVI) into a leaving group O-LG2 to generate a compound of formula (XVIII). Typically LG2 is sulfonyl group, such as a trifluoromethylsulfonyl group.

[0891] Step 11 comprises coupling of the compound of formula (XVII) with a compound of formula LG3-(CH2)n-OPG2under aryl coupling conditions to generate a compound of formula (XIX). Typically LG3 is a trihaloborate such as trifluoroborate, and PG2 is a silyl group, such as a tert-butyldimethylsilyl group.

[0892] The reaction is typically carried out in the presence of a suitable aryl coupling catalyst and a base. Typical aryl coupling catalysts include palladium (II) salts such as PdCh(dppf).

[0893] Typical bases include alkali metal carbonates such as caesium carbonate.

[0894] Step 12 comprises deprotection of the compound of formula (XIX) to generate a compound of formula (IA”). This can be carried out under suitable deprotection conditions well known to those skilled in the art. When the protecting group PG2 is a silyl group, the reaction istypically carried out in the presence of trifluoroacetic acid or a reagent that releases fluoride ions, such as tetrabutylammonium fluoride (TBAF).

[0895] Method 1B. Synthesis of Payload Compounds of Formula (I)

[0896] Compounds of Formula (I’”) wherein X is S may be made according to Scheme 1B. In Scheme 1B, A is alkylene where n = 1 to 10; PGi is a hydroxyl-protecting group, preferably a silyl group, more preferably tert-butyldimethylsilyl.

[0897]

[0898] Scheme 1B

[0899] Step 1 comprises substitution of a compound of formula (XX) with a compound of formula (XXI) to generate a compound of formula (XXII). The reaction is typically carried out in the presence of a base, typically a weak base. In one embodiment, the base is a carbonate salt, typically potassium carbonate.

[0900] Step 2 comprises reduction of the nitro group of a compound of formula (XXII) to generate the amine group of a compound of formula (XXIII). As part of this reaction, the protecting group PGi of the compound of formula (XXII) is cleaved.

[0901] The reaction is typically carried out in the presence of a suitable reducing agent and an acid, typically a weak acid. Typical reducing agents include iron. Typical acids include ammonium chloride.

[0902] Step 3 comprises reaction of a compound of formula (XXIII) with a compound of formula (V) to generate a compound of formula (I’”). The reaction is typically carried out in the presence of an acid catalyst or a suitable salt. In one embodiment, the acid catalyst is a sulfonic acid, such as p-toluenesulfonic acid, or a salt thereof, preferably the pyridinium salt, pyridinium p-toluenesulfonate (PPTS).Method 2. Synthesis of Linker-Payload Conjugates of Formula (II)

[0903] The linker-payload compounds of formula (II) may be formed by conjugating the payload compounds of formula (I) to molecules containing a whole or part of the linker L. This can be carried out by a number of methods well known to those skilled in the art.

[0904] In particular, wherein the linker L contains a peptide moiety P, this part of the linker may be synthesised by standard peptide synthetic methods well known to those skilled in the art.

[0905] By way of example, compounds of Formula (HA) may be made according to Scheme 2. This synthesis is equally applicable for compounds of formula (II) wherein Ri and R4 do not form a carbocyclic ring. The synthesis is shown for compounds wherein X is O, but is also applicable to compounds of formula (II) wherein X is S. The synthesis is shown for compounds wherein L is a group of formula (L2), but is also applicable to the other linkers L which include a peptide moiety P.

[0906]

[0907] Scheme 2Step 1 comprises etherification of the compound of formula (IA) by reaction with a compound formula (XX), wherein PG is an amine-protecting group, to generate a compound of formula (XXI). Typical amine-protecting groups PG include 9-fluorenylmethoxycarbonyl (Fmoc). The reaction is typically carried out in the presence of a suitable catalyst, typically a Lewis acid catalyst such as boron trifluoride.

[0908] Step 2 comprises deprotection of the compound of formula (XXI) to generate a compound of formula (XXII). This can be carried out under suitable deprotection conditions well known to those skilled in the art. When the protecting group PG is an Fmoc group, the reaction is typically carried out in the presence of a base, such as DBU.

[0909] Step 3 comprises coupling of the compound of formula (XXII) with a suitable intermediate to generate a compound of formula (HA). This can be carried out under standard amide coupling conditions well known to those skilled in the art. The reaction is typically carried out using an activating agent, examples of which include 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methyl-morpholinium chloride (DMTMM).

[0910] Method 3. Synthesis of Binding Molecule- Linker- Payload Conjugates of Formula (III)

[0911] The binding molecule-linker-payload conjugates of formula (III) may be formed by conjugating a linker-payload of formula (II) to a binding molecule, such as an antibody. This can be carried out by a number of methods well known to those skilled in the art.

[0912] In one embodiment of such a method, the method comprises:

[0913] (a) reducing the disulfide bonds on the relevant amino acid residues (typically cysteine residues) on the binding molecule BM, to generate an activated form of the binding molecule in which the thiol groups on the relevant amino acids are free; and

[0914] (b) reacting the activated form of the binding molecule BM with the linker-payload conjugate of formula (II), thereby conjugating the linker-payload moiety to the binding molecule BM to form the compound of formula (III).

[0915] A generalised method for conjugation of a linker-payload of formula (II) to an I gG 1 antibody (shown generally by reference to its heavy and light chains) is shown in Scheme 3 below. In this particular synthetic route, the group Y is a sulfone group which is displaced by the thiol groups of the antibody to generate a thioether bond to the linker-payload moiety, and R represents generally the remainder of the linker-payload moiety.

[0916]

[0917] Scheme 3

[0918] Salts, Solvates, Polymorphs, Enantiomers, Isotopically Labelled Derivatives

[0919] Pharmaceutically acceptable salts of the compounds of formulae (I), (II) and (III) include the acid addition and base salts thereof.

[0920] Suitable acid addition salts are formed from acids which form non-toxic salts. Examples include the acetate, adipate, aspartate, benzoate, besylate, bicarbonate / carbonate, bisulphate / sulphate, borate, camsylate, citrate, cyclamate, edisylate, esylate, formate, fumarate, gluceptate, gluconate, glucuronate, hexafluorophosphate, hibenzate, hydrochloride / chloride, hydrobromide / bromide, hydroiodide / iodide, isethionate, lactate, malate, maleate, malonate, mesylate, methylsulphate, naphthylate, 2-napsylate, nicotinate, nitrate, orotate, oxalate, palmitate, pamoate, phosphate / hydrogen phosphate / dihydrogen phosphate, pyroglutamate, saccharate, stearate, succinate, tannate, tartrate, tosylate, trifluoroacetate and xinafoate salts.

[0921] Suitable base salts are formed from bases which form non-toxic salts. Examples include the aluminium, arginine, benzathine, calcium, choline, diethylamine, diolamine, glycine, lysine, magnesium, meglumine, olamine, potassium, sodium, tromethamine and zinc salts.

[0922] Hemisalts of acids and bases may also be formed, for example, hemisulphate and hemicalcium salts.

[0923] For a review on suitable salts, see Handbook of Pharmaceutical Salts: Properties, Selection, and Use by Stahl and Wermuth (Wiley-VCH, 2002).

[0924] Pharmaceutically acceptable salts of compounds of formula I may be prepared by one or more of three methods:(i) by reacting the compound of formula I with the desired acid or base;

[0925] (ii) by removing an acid- or base-labile protecting group from a suitable precursor of the compound of formula (I) or by ring-opening a suitable cyclic precursor, for example, a lactone or lactam, using the desired acid or base; or

[0926] (iii) by converting one salt of the compound of formula (I) to another by reaction with an appropriate acid or base or by means of a suitable ion exchange column.

[0927] All three reactions are typically carried out in solution. The resulting salt may precipitate out and be collected by filtration or may be recovered by evaporation of the solvent. The degree of ionisation in the resulting salt may vary from completely ionised to almost non-ionised.

[0928] The compounds of the invention may exist in a continuum of solid states ranging from fully amorphous to fully crystalline. The term 'amorphous' refers to a state in which the material lacks long range order at the molecular level and, depending upon temperature, may exhibit the physical properties of a solid or a liquid. Typically such materials do not give distinctive X-ray diffraction patterns and, while exhibiting the properties of a solid, are more formally described as a liquid. Upon heating, a change from solid to liquid properties occurs which is characterised by a change of state, typically second order ('glass transition').

[0929] The term 'crystalline' refers to a solid phase in which the material has a regular ordered internal structure at the molecular level and gives a distinctive X-ray diffraction pattern with defined peaks. Such materials when heated sufficiently will also exhibit the properties of a liquid, but the change from solid to liquid is characterised by a phase change, typically first order ('melting point').

[0930] The compounds of the invention may also exist in unsolvated and solvated forms.

[0931] The term 'solvate' is used herein to describe a molecular complex comprising the compound of the invention and one or more pharmaceutically acceptable solvent molecules, for example, ethanol. The term 'hydrate' is employed when said solvent is water.

[0932] A currently accepted classification system for organic hydrates is one that defines isolated site, channel, or metal-ion coordinated hydrates - see Polymorphism in Pharmaceutical Solids by K. R. Morris (Ed. H. G. Brittain, Marcel Dekker, 1995). Isolated site hydrates are ones in which the water molecules are isolated from direct contact with each other by intervening organic molecules. In channel hydrates, the water molecules lie in lattice channels where they are next to other water molecules. In metal-ion coordinated hydrates, the water molecules are bonded to the metal ion. When the solvent or water is tightly bound,the complex will have a well-defined stoichiometry independent of humidity. When, however, the solvent or water is weakly bound, as in channel solvates and hygroscopic compounds, the water / solvent content will be dependent on humidity and drying conditions. In such cases, non- stoichiometry will be the norm.

[0933] In this specification all references to compounds of formula I include references to pharmaceutically acceptable salts and solvates thereof.

[0934] The compounds of the invention include compounds of formula (I) as hereinbefore defined, including all polymorphs and crystal habits thereof, prodrugs and isomers thereof (including optical, geometric and tautomeric isomers) as hereinafter defined and isotopically-labelled compounds of formula (I).

[0935] Compounds of formula I containing one or more asymmetric carbon atoms can exist as two or more stereoisomers. Where structural isomers are interconvertible via a low energy barrier, tautomeric isomerism ('tautomerism') can occur. This can take the form of proton tautomerism in compounds of formula I containing, for example, an imino, keto, or oxime group, or so-called valence tautomerism in compounds which contain an aromatic moiety. It follows that a single compound may exhibit more than one type of isomerism.

[0936] Included within the scope of the present invention are all stereoisomers, geometric isomers and tautomeric forms of the compounds of formula (I), including compounds exhibiting more than one type of isomerism, and mixtures of one or more thereof. Also included are acid addition or base salts wherein the counterion is optically active, for example, d-lactate or / -lysine, or racemic, for example, d--tartrate or dAarginine.

[0937] Cis / trans isomers may be separated by conventional techniques well known to those skilled in the art, for example, chromatography and fractional crystallisation. Conventional techniques for the preparation / isolation of individual enantiomers include chiral synthesis from a suitable optically pure precursor or resolution of the racemate (or the racemate of a salt or derivative) using, for example, chiral high pressure liquid chromatography (HPLC).

[0938] Alternatively, the racemate (or a racemic precursor) may be reacted with a suitable optically active compound, for example, an alcohol, or, in the case where the compound of formula (I) contains an acidic or basic moiety, a base or acid such as 1 -phenylethylamine or tartaric acid. The resulting diastereomeric mixture may be separated by chromatography and / orfractional crystallization and one or both of the diastereoisomers converted to the corresponding pure enantiomer(s) by means well known to a skilled person.

[0939] Chiral compounds of the invention (and chiral precursors thereof) may be obtained in enantiomerically-enriched form using chromatography, typically HPLC, on an asymmetric resin with a mobile phase consisting of a hydrocarbon, typically heptane or hexane, containing from 0 to 50% by volume of isopropanol, typically from 2% to 20%, and from 0 to 5% by volume of an alkylamine, typically 0.1% diethylamine. Concentration of the eluate affords the enriched mixture.

[0940] When any racemate crystallises, crystals of two different types are possible. The first type is the racemic compound (true racemate) referred to above wherein one homogeneous form of crystal is produced containing both enantiomers in equimolar amounts. The second type is the racemic mixture or conglomerate wherein two forms of crystal are produced in equimolar amounts each comprising a single enantiomer.

[0941] While both of the crystal forms present in a racemic mixture have identical physical properties, they may have different physical properties compared to the true racemate. Racemic mixtures may be separated by conventional techniques known to those skilled in the art - see, for example, Stereochemistry of Organic Compounds by E. L. Eliel and S. H. Wilen (Wiley, 1994).

[0942] The present invention includes all pharmaceutically acceptable isotopically-l abelled compounds of formula (I), (II) and (III), wherein one or more atoms are replaced by atoms having the same atomic number, but an atomic mass or mass number different from the atomic mass or mass number which predominates in nature.

[0943] Examples of isotopes suitable for inclusion in the compounds of the invention include isotopes of hydrogen, such as2H and3H, carbon, such as11C,13C and14C, chlorine, such as36CI, fluorine, such as18F, iodine, such as123l and125l, nitrogen, such as13N and15N, and oxygen, such as150,17O and18O.

[0944] Certain isotopically-labelled compounds of formula (I), (II) and (III), for example, those incorporating a radioactive isotope, are useful in drug and / or substrate tissue distribution studies. The radioactive isotopes tritium, i.e.3H, and carbon-14, i.e.14C, are particularly useful for this purpose in view of their ease of incorporation and ready means of detection.Substitution with heavier isotopes such as deuterium, i.e.2H, may afford certain therapeutic advantages resulting from greater metabolic stability, for example, increased in vivo half-life or reduced dosage requirements, and hence may be preferred in some circumstances.

[0945] Substitution with positron emitting isotopes, such as11C,18F,15O and13N, can be useful in Positron Emission Topography (PET) studies for examining substrate receptor occupancy.

[0946] Isotopically-labelled compounds of formula I can generally be prepared by conventional techniques known to those skilled in the art or by processes analogous to those described in the accompanying Examples and Intermediates using an appropriate isotopically-labelled reagent in place of the non-labelled reagent previously employed.

[0947] Pharmaceutically acceptable solvates in accordance with the invention include those wherein the solvent of crystallization may be isotopically substituted, e.g. D2O, d6-acetone, d6-DMS.

[0948] Pharmaceutical Compositions

[0949] The present invention also provides a pharmaceutical composition which comprises a compound of formula (I), (II) or (III) according to the invention, both in their broadest aspects and all preferred aspects, together with a pharmaceutically acceptable carrier, diluent or excipient.

[0950] In some embodiments, the compositions described herein may further comprise one or more selected from this list consisting of: an adjuvant, salt, active polypeptide, compound, component and active agent.

[0951] Compositions typically should be sterile and stable under the conditions of manufacture and storage. The composition according to the invention may be produced using current good manufacturing practices (CGMP).

[0952] The pharmaceutical composition may be formulated to be suitable for administration to a patient in order to prevent and / or treat disease. Pharmaceutical compositions can be formulated for administration by different routes, for example, for oral, parenteral, topical, inhalative, intravenous, intramuscular, rectal, sublingual, transdermal, subcutaneous, intratumoral application routes, according to their chemical and physical properties.The pharmaceutical composition may be in the form of a tablet, a coated tablet, powder, granulate, a pellet, a capsule, an effervescent tablet or a transdermal therapeutic system. The pharmaceutical composition may be in the form of a liquid composition, selected from the group consisting of a solution, a syrup, an infusion, an extract, a solution for intravenous application, or a solution for infusion. The pharmaceutical composition may be in the form of a semisolid composition such as an emulsion, a suspension, a cream, a lotion, a gel, a globule, a buccal tablet or a suppository.

[0953] The term “carrier”, as used herein, may refer to a diluent, adjuvant, excipient, or vehicle. Such carriers can be sterile liquids, such as saline solutions in water and oils, including those of petroleum, animal, vegetable or synthetic origin, such as peanut oil, soybean oil, mineral oil, sesame oil. A sterile saline solution is a preferred carrier.

[0954] Saline solutions and aqueous dextrose and glycerol solutions can also be employed as liquid carriers. Suitable excipients include starch, glucose, lactose, sucrose, gelatin, malt, rice, flour, chalk, silica gel, sodium stearate, glycerol monostearate, talc, sodium chloride, dried skim milk, glycerol, propylene, glycol, water, ethanol and the like.

[0955] The composition, if desired, can also contain minor amounts of wetting or emulsifying agents, or pH buffering agents. The composition of the invention can be formulated as neutral or salt forms. Salts include those formed with free amino groups such as those derived from hydrochloric, phosphoric, acetic, oxalic, tartaric acids, etc., and those formed with free carboxyl groups such as those derived from sodium, potassium, ammonium, calcium, ferric hydroxides, isopropylamine, triethylamine, 2-ethylamino ethanol, histidine, procaine, etc.

[0956] In some embodiments, the salt may comprise a metal cation, such as a sodium salt or a potassium salt.

[0957] In some embodiments, the composition may comprise an aqueous diluent or solvent. In some embodiments, the aqueous diluent or solvent may be a phosphate buffered saline solution, such as a sterile phosphate buffered saline solution.

[0958] In some embodiments, the composition may comprise one or more vesicles, nanoparticles, lipid nanoparticle (LNPs), liposomes or polymeric mixtures.The composition may enable delivery of a nucleic acid(s) according to the invention and / or a vector according to the invention to a cell.

[0959] Kit

[0960] The present invention also provides a kit comprising the payload, payload-linker and binding molecule-linker-payload conjugates according to the invention. The present invention also provides a kit comprising the composition according to the invention.

[0961] Dosage

[0962] For administration to human patients, the total daily dose of the compounds of the invention is typically in the range 1 mg to 5000 mg, preferably 10 mg to 2000 mg, more preferably 50 mg to 1500 mg, and still more preferably 100 to 500 mg depending, of course, on the mode of administration. The total daily dose may be administered in single or divided doses and may, at the physician's discretion, fall outside of the typical range given herein.

[0963] These dosages are based on an average human subject having a weight of about 60kg to 70kg. The physician will readily be able to determine doses for subjects whose weight falls outside this range, such as infants and the elderly.

[0964] For the avoidance of doubt, references herein to "treatment" include references to curative, palliative and prophylactic treatment.

[0965] Medical Uses and Methods of Treatment

[0966] The compounds of the invention are indicated as pharmaceuticals. According to a further aspect of the invention there is provided a compound of the invention, as hereinbefore defined, for use as a pharmaceutical.

[0967] Compounds of the invention may be shown to be active e.g. in the biochemical assays described herein.

[0968] The disorders / conditions that the compounds of the invention may be useful in treating hence include cancer (such as lymphomas, solid tumours or a cancer as described hereinafter), inflammatory and autoimmune diseases, for example rheumatoid arthritis, psoriasis, psoriatic arthritis, osteoarthritis, ankylosing spondylitis, atopic dermatitis,inflammatory bowel diseases such as ulcerative colitis and Crohn’s disease, systemic lupus erythematosus, lupus nephritis, multiple sclerosis, peanut allergy, asthma and celiac disease).

[0969] According to a further aspect of the present invention, there is provided a compound of the invention, as hereinbefore defined, for use in the treatment of cancer.

[0970] According to a further aspect of the present invention, there is provided use of a compound of the invention, as hereinbefore defined, in the manufacture of a medicament for the treatment of cancer.

[0971] According to a further aspect of the present invention, there is provided a method of treatment of cancer, which method comprises administration of a therapeutically effective amount of a compound of the invention, as hereinbefore defined, to a patient suffering from, or susceptible to, such a condition.

[0972] According to a further aspect of the present invention, there is provided a compound of the invention, as hereinbefore defined, for use in the treatment of cancer.

[0973] As stated above, the compounds of the invention may be useful in the treatment of cancer. More, specifically, the compounds of the invention may therefore be useful in the treatment of a variety of cancer including, but not limited to: carcinoma such as cancer of the bladder, breast, colon, kidney, liver, lung (including non-small cell cancer and small cell lung cancer), oesophagus, gall-bladder, ovary, pancreas, stomach, cervix, thyroid, prostate, skin, squamous cell carcinoma, testis, genitourinary tract, larynx, glioblastoma, neuroblastoma, keratoacanthoma, epidermoid carcinoma, large cell carcinoma, non-small cell lung carcinoma, small cell lung carcinoma, lung adenocarcinoma, bone, adenoma, adenocarcinoma, follicular carcinoma, undifferentiated carcinoma, papilliary carcinoma, seminoma, melanoma, sarcoma, bladder carcinoma, liver carcinoma and biliary passages, kidney carcinoma, myeloid disorders, lymphoid disorders, hairy cells, buccal cavity and pharynx (oral), lip, tongue, mouth, pharynx, small intestine, colon-rectum, large intestine, rectum, brain and central nervous system, Hodgkin’s and leukaemia; hematopoietic tumours of lymphoid lineage, including leukaemia, acute lymphocitic leukaemia, acute lymphoblastic leukaemia, B-cell lymphoma, T-cell-lymphoma, mantle cell lymphoma, Hodgkin’s lymphoma, non-Hodgkin’s lymphoma, hairy cell lymphoma and Burkett's lymphoma; hematopoietic tumours of myeloid lineage, including acute and chronic myelogenous leukaemias, myelodysplastic syndrome and promyelocytic leukemia; tumors of mesenchymal origin,including fibrosarcoma and rhabdomyosarcoma; tumours of the central and peripheral nervous system, including astrocytoma, neuroblastoma, glioma and schwannomas; and other tumours, including melanoma, seminoma, teratocarcinoma, osteosarcoma, xeroderma pigmentosum, keratoxanthoma, thyroid follicular cancer and Kaposi’s sarcoma.

[0974] According to a further aspect of the present invention, there is provided use of a compound of the invention, as hereinbefore defined, in the manufacture of a medicament for the treatment of an autoimmune disease or an inflammatory disease.

[0975] According to a further aspect of the present invention, there is provided a method of treatment of an autoimmune disease or an inflammatory disease, which method comprises administration of a therapeutically effective amount of a compound of the invention, as hereinbefore defined, to a patient suffering from, or susceptible to, such a condition.

[0976] According to a further aspect of the present invention, there is provided a compound of the invention, as hereinbefore defined, for use in the treatment of an autoimmune disease or an inflammatory disease.

[0977] Examples of autoimmune disease and / or inflammatory diseases include but are not limited to coeliac disease, psoriasis, inflammatory bowel diseases such as colitis and Crohn’s disease, multiple sclerosis, rheumatoid arthritis, systemic lupus erythematosus, aplastic anaemia, myocarditis, autoimmune hepatitis, primary biliary cholangitis, alopecia areata, autoimmune urticaria, perphigus vulgaris, autoimmune polyendocrine syndrome (APS), autoimmune pancreatitis, type 1 diabetes, autoimmune thyroiditis, Sjogren’s syndrome, autoimmune haemolytic anaemia, gastritis vasculitis, granlumatosis with polyangitis, autoimmune uveitis, myasthenia gravis, acute disseminated encephalomyelitis, relapsing polychrondritis, Lambert-Eaton myasthenic syndrome, Hashimoto’s encephalopathy, Felty syndrome, autoimmune thyroiditis, Graves’ disease, nephritis, bullous pemphigoid, dermatitis, epidermolysis bullosa acquisita, linear IgA disease, autoimmune lymphoprolifeative syndrome, autoimmune neutropenia, autoimmune thrombocytopenis purpura, cold agglutinin disease, Evans syndrome, pernicious anaemia, Still’s disease, psoriatic arthritis, rheumatic fever, Guillain-Barre syndrome, Ord’s thyroiditis, ankylosing spondylitis, atopic dermatitis, systemic sclerosis (scleroderma), hidradenitis suppurativa, lupus nephritis, peanut allergy, and asthma.

[0978] Compounds of the invention are indicated both in the therapeutic and / or prophylactic treatment of the above-mentioned conditions.“Patients” include mammalian (including human) patients. Hence, the method of treatment discussed above may include the treatment of a human or animal body.

[0979] The term “effective amount” refers to an amount of a compound, which confers a therapeutic effect on the treated patient. The effect may be objective (e.g. measurable by some test or marker) or subjective (e.g. the subject gives an indication of or feels an effect).

[0980] Examples

[0981] Abbreviations

[0982] AMU atomic mass units

[0983] DIC N,N'-Diisopropylcarbodiimide

[0984] DIPEA N,N'-Diisopropylethylamine

[0985] DMTMM 4-(4,6-dimethoxy-1 ,3,5-triazin-2-yl)-4-methyl-morpholinium chloride

[0986] EDC 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide

[0987] HATU Hexafluorophosphate Azabenzotriazole Tetramethyl Uronium salt

[0988] ELSD Evaporative light scattering detection

[0989] HFIP 1,1,1,3,3,3-Hexafluoropropan-2-ol

[0990] HPLC High performance liquid chromatography

[0991] LRMS Low Resolution Mass Spectrum

[0992] PPTS Pyridinium p-toluenesulfonate

[0993] TEA Triethylamine

[0994] TFA Trifluoroacetic acid

[0995] TMG tetramethylguanidine

[0996] General Experimental Conditions

[0997] Compounds were purchased unless synthetic routes for their preparation are indicated. All synthetic reactions were conducted under positive nitrogen pressure with magnetic stirring unless otherwise stated. Centrifugation was done with a single speed (2,000 x g) Fisher Scientific mini-centrifuge, using 6 mm x 50 mm glass culture tubes. Chromatographic purifications were conducted on either a Biotage Select with uv / vis detection in the 220 nm -400 nm range or a Teledyne 300+ Next generation Flash chromatography unit with uv / vis detection in the 220 nm - 400 nm range and / or with ELSD detection. Flash chromatography uv / vis detection also used background solvent subtraction. UPLC-MS analyses were performed on a Waters Acquity system with mass detection in the 50 AMU - 2000 AMUrange with a BEH C18 103 A, 1.4 m, 2.1 mm x 100 mm column and eluting at 0.5 mL / min with deionized water containing 0.1% TFA and a gradient of acetonitrile containing 0.1% TFA 5 - 90% over 5 min then acetonitrile 100% for 1 min and column re-equilibration with 95:5 (deionized water containing 0.1% TFA: acetonitrile containing 0.1% TFA) for 1 min.

[0998] Preparation 1: Synthesis of Intermediates 1, 2, and 3

[0999] The synthesis of Intermediates 1, 2 and 3 is shown in Scheme 4 and described below.

[1000]

[1001] Scheme 4

[1002] Intermediate 1: To a stirring solution of 2-(methylthio)pyrimidine-5-carboxylic acid (493.1 mg, 2.78 mmol, Sigma-Aldrich) in 15 ml of dichloromethane was added 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) (547.4 mg, 2.78 mmol), 1-hydroxy-7-azabenzotriazole (378.4 mg, 2.78 mmol) and then diisopropylethylamine (484 pL, 2.78 mmol) at room temperature. After 10 min, a solution of MeNH-PEG2-CH2COOtBu (493.1 mg, 2.78 mmol, IPIusChem) in dichloromethane was added. After an additional 1.5 h, the reaction was diluted with dichloromethane and washed three times with 0.05N HCI and three times with saturated sodium bicarbonate. The organic layer was dried over sodium sulfate, filtered, and concentrated under reduced pressure to afford 867 mg of Intermediate 1 as a yellow oil. The material was used as is in the next step without further purification. LC / MS C17H27N3O5S (M + H)+calcd. 356.48 m / z, found (M+H)+386.57 m / z, observed (M+H-tBu)+330.44 m / z.

[1003] Intermediate 2: To a stirring solution of crude Intermediate 1 from the previous step in 11 mL of dichloromethane was added 11 mL of trifluoroacetic acid at room temperature. After 20 h, the reaction was concentrated under reduced pressure to afford Intermediate 2. The material was used as is in the next step without further purification. LC / MS C13H19N3O5S (M + H)+calcd. 330.37 m / z, found (M+H)+ 330.42 m / z.Intermediate 3: To a stirring solution of crude Intermediate 2 from the previous step in 14 ml of deionized water was added OXONE (1.64 g, 5.35 mmol) at 0 °C. After 1.5 h, the product was isolated by solid-phase extraction with Waters Sep-Pak tC1835cc cartridges. The fractions containing product were concentrated under reduced pressure. The resulting material was taken up in a solution of 1:1 water / acetonitrile. The solution was dried via lyophilization to afford 721 mg of Intermediate 3 (93%) as a yellow residue. LC / MS C13H19N3O7S (M + H)+calcd. 362.37 m / z, found (M+H)+362.18 m / z.

[1004] Preparation 2: Synthesis of Intermediate 5

[1005] The synthesis of Intermediate 5 is shown in Scheme 5 and described below.

[1006]

[1007] Scheme 5

[1008] Intermediate 4a: To a stirring solution of Cbz-Val-OSu (1.0 g, 2.87 mmol, Chem-lmpex) in 15 ml of DMF was added H-Lys(Boc)-OH (742 mg, 3.01 mmol) followed by diisopropylethylamine (1.25 mL, 7.18 mmol) at room temperature. After 16 h, the reaction was concentrated, and the resulting material was taken up in ethyl acetate. The organic layer was washed with a saturated aqueous citric acid solution. Then the organic layer was dried over sodium sulfate, filtered, and concentrated under reduced pressure. The resulting solids were dissolved in 5 ml of methanol and then precipitated into 80 ml of deionized water. The resulting mixture was spun at 3700 rpm for 10 min. The supernatant was removed, and the solids were dried via lyophilization to afford 1.26 g of Intermediate 4a

[1009] (92% yield) as a white solid. LC / MS C24H37N3O7 (M+H)+calcd. 480.57 m / z, found (M+Na)+502.32 m / z. (502 m / z Na+)

[1010] Intermediate 4b: To a stirring mixture of Intermediate 4a (1.26 g, 2.63 mmol) in 15 ml of ethyl acetate was added 4 M HCI in dioxane at room temperature. After 1 h, the reaction was concentrated under reduced pressure to afford 1.2 g of crude Intermediate 4b as a whitesolid. The material was used as is without further purification. LC / MS C19H29N3O5 (M+H)+calcd. 380.46 m / z, found (M+H)+380.23 m / z.

[1011] Intermediate 4c: To a stirring mixture of Intermediate 4b (1.0 g, 2.89 mmol) in 20 ml of dichloromethane was added propionaldehyde (1.24 ml, 17.3 mmol) at room temperature. After 20 min, STAB was added. After an additional 2 h, 10 ml of saturated aqueous ammonium chloride was added. The reaction was stirred for 2 h and then extracted four times with dichloromethane. The combined organic layers were concentrated under reduced pressure. The resulting residue was dissolved in 4 ml of dichloromethane and precipitated into chilled 80 ml of diethyl ether. The mixture was spun at 3700 rpm for 10 min. The supernatant was removed and the solids were dried under reduced pressure to afford 1.05 g of Intermediate 4c (79% yield) as a white foam. LC / MS C25H41N3O5 (M+H)+calcd. 464.62 m / z, found (M+H)+464.33 m / z.

[1012] Intermediate 5: To a stirring solution of Intermediate 4c (1.0 g, 2.16 mmol) in 40 ml of methanol was added 2 ml of water and 2 ml of formic acid at room temperature. The flask was repeatedly purged and filled with nitrogen. To the resulting solution was added 5% palladium on carbon (500 mg). The reaction was stirred under nitrogen. After 16 h, the reaction was diluted with methanol and filtered through pre-rinsed CeliteOwith 0.5% formic acid in methanol. The filtrate was concentrated under reduced pressure and the residue was taken up in water with 20% acetonitrile. The solution was dried via lyophilization. The dried solids were then taken up in 1 N HCI and dried via lyophilization to afford 842 mg of Intermediate 5 (97% yield) as the HCI salt. LC / MS C17H35N3O3 (M+H)+calcd. 330.49 m / z, found (M+H)+330.57 m / z.

[1013] Preparation 2A: Synthesis of Intermediate 7

[1014] The synthesis of Intermediate 7 is shown in Scheme 6 and described below.

[1015]

[1016] Scheme 6Intermediate 7: The tripeptide was synthesized using standard Fmoc solid phase peptide chemistry. The peptide was synthesized using automated microwave peptide synthesis with 0.25 mmol of commercially available 2-chlorotrityl-chloride resin loaded with a Fmoc-2PAL-OH residue. To a fritted syringe was added 0.25 mmol of 2-CTC resin (0.53 mmol / g, 472 mg). The resin was swelled with 8 mL of dichloromethane for 15 min. To the resin was added N-Fmoc-3-(2-pyridyl)-L-alanine (194.2 mg, 0.5 mmol) dissolved in 8 ml dichloromethane and DIPEA (174.2 pl, 1.0 mmol). The reaction was agitated for 20 h. The solution was evacuated from the fritted syringe, after which the resin was treated two times with a 10 ml solution of 92.5% dichloromethane, 5.0% MeOH, and 2.5% DIPEA. Fmoc-protected residues were coupled using DIG, DIPEA, and oxyma for 2x10 min under microwave assistance at 50 °C. Double couplings were performed and Fmoc deprotection was performed with 20% piperidine in DMF for 3 min at 60 °C. Cleavage from resin was performed by treating the resin three times with 25% hexafluoro-2-propanol in dichloromethane and agitating for 15 minutes. Between each treatment, the solution was evacuated from the fritted syringe, and the resulting solution was concentrated under reduced pressure. The dried residue was taken up in 3 ml of a solution of 1:1 water / MeCN with 0.05% v / v TFA and dried via lyophilization to afford compound XXh. . LC / MS C12H16N4O4 (M + H)+calcd. 281.28 m / z, found (M+H)+281.22 m / z.

[1017] Preparation 2B: Synthesis of Intermediates 7a and 7b

[1018] The synthesis of Intermediates 7a and 7b are shown in Scheme 6A and described below.

[1019]

[1020] n- Scheme 6AIntermediate 7a: The tripeptide was synthesized using standard Fmoc solid phase peptide chemistry on an automated microwave peptide synthesizer. To a fritted syringe was added 0.25 mmol of commercially available 2-chlorotrityl-chloride resin (0.53 mmol / g, 472 mg). The resin was swelled with 8 mL of dichloromethane for 15 min. Then a solution of / V-Fmoc-3-(3-pyridyl)-L-alanine (Fmoc-3-Pal-OH, 194.2 mg, 0.5 mmol) in 8 mL of dichloromethane containing / V, / V-diisopropylethylamine (174.2 pl, 1.0 mmol) was added to the resin. The reaction was agitated for 20 h. The solution was evacuated from the fritted syringe, after which the resin was treated two times with a 10 mL solution of 92.5% dichloromethane, 5.0% MeOH, and 2.5% / V, / V-diisopropylethylamine. Then Fmoc-protected amino acid residues were coupled using standard / V, / V'-diisopropylcarbodiimide (DIC), / V, / V-diisopropylethylamine, and Oxyma conditions. The coupling procedure was reacted for 10 min at 50 °C and the process was repeated to ensure complete coupling. After completion of the peptide sequence, Fmoc deprotection was performed using a solution of 20% piperidine in DMF for 3 min at 60 °C. The peptide was cleaved from the resin by incubation with 8 mL of equal parts trifluoroacetic acid and dichloromethane for 3 h. After treatment, the solution was drained from the fritted syringe, and the collected solution was concentrated under reduced pressure. The dried residue was dissolved in 3 mL of a 1 : 1 mixture of water and MeCN containing 0.05% v / v TFA, then dried via lyophilization to afford 52.4 mg of Intermediate 7a (74.8% yield). LC / MS for C12H16N4O4 [M+H]+calcd. 281.28 m / z, found 281.15 m / z.

[1021] Intermediate 7b: The tripeptide was synthesized using standard Fmoc solid phase peptide chemistry on an automated microwave peptide synthesizer. To a fritted syringe was added 0.25 mmol of commercially available 2-chlorotrityl-chloride resin (0.53 mmol / g, 472 mg). The resin was swelled with 8 mL of dichloromethane for 15 min. Then a solution of / V-Fmoc-3-(4-pyridyl)-L-alanine (Fmoc-4-Pal-OH, 194.2 mg, 0.5 mmol) in 8 mL of dichloromethane containing / V, / V-diisopropylethylamine (174.2 pl, 1.0 mmol) was added to the resin. The reaction was agitated for 20 h. The solution was evacuated from the fritted syringe, after which the resin was treated two times with a 10 mL solution of 92.5% dichloromethane, 5.0% MeOH, and 2.5% / V, / V-diisopropylethylamine. Then Fmoc-protected amino acid residues were coupled using standard / V, / V'-diisopropylcarbodiimide (DIC), / V, / V-diisopropylethylamine, and Oxyma conditions. The coupling procedure was reacted for 10 min at 50 °C and the process was repeated to ensure complete coupling. After completion of the peptide sequence, Fmoc deprotection was performed using a solution of 20% piperidine in DMF for 3 min at 60 °C. The peptide was cleaved from the resin by incubation with 8 mL of equal parts trifluoroacetic acid and dichloromethane for 3 h. After treatment, the solution was drained from the fritted syringe, and the collected solution was concentrated under reducedpressure. The dried residue was dissolved in 3 mL of a 1 : 1 mixture of water and MeCN containing 0.05% v / v TFA, then dried via lyophilization to afford 45.9 mg of Intermediate 7b (65.6% yield). LC / MS for C12H16N4O4 [M+H]+calcd. 281.28 m / z, found 281.18 m / z.

[1022] Preparation 3: Synthesis of Intermediates 6, 8 and 9

[1023] The synthesis of intermediates 6, 8, and 9 is shown in Scheme 7 and described below.

[1024]

[1025] Scheme 7

[1026] General procedure: To a fritted syringe containing polymer-bound / V-Benzyl-A / '-cyclohexylcarbodiimide (1.0 g / mol, 0.332 mmol, 2 equiv.) was added Intermediate 3 ( 0.166 mmol) in a solution of 8 ml of dichloromethane. To the reaction solution was added N-hydroxysuccinimide (0.166 mmol, 1 equiv.). The reaction was placed on shaker for 1 h before draining solution into a vial. The solution was concentrated under reduced pressure. The resulting residue was taken up in 1.6 ml of DMF and the peptide (0.157 mmol, 0.95 equiv.) was added. The product was isolated via HPLC. Fractions were pooled and dried via lyophilization to afford the product as a white foam.Intermediate 6: The compound was synthesized using the general procedure and Intermediate 5 (207mg, 0.565mmol) as the peptide. Afforded 117mg of Intermediate 6 (34% yield). LC / MS C30H52N6O9S (M+H)+calcd. 673.84 m / z, found (M+H)+673.84 m / z.

[1027] Intermediate 8: The compound was synthesized using the general procedure and commercially available H-Gly-Gly-Phe-OH (44.12mg, 0.157mmol, Combi-Blocks) as the peptide. . Afforded 52.2mg of Intermediate 8 (53% yield). LC / MS C26H34N6O10S (M+H)+calcd. 623.65 m / z, found (M+H)+623.74 m / z.

[1028] Intermediate 9: The compound was synthesized using the general procedure and Intermediate 5 as the peptide. Afforded 53.5mg of Intermediate 9 (22% yield). LC / MS C25H33N7O10S (M+H)+calcd. 624.64 m / z, found (M+H)+624.68 m / z.

[1029] Preparation 3A: Synthesis of Intermediates 3a, 12 and 13

[1030] The synthesis of intermediates 3a, 12 and 13 is shown in Scheme 7A and described below.

[1031]

[1032] Scheme 7A

[1033] Intermediate 3a: To a fritted syringe containing resin-bound / V-Benzyl- / V'-cyclohexylcarbodiimide (1.0 g / mol, 0.332 mmol, Sigma-Aldrich) was added a solution of intermediate 3 (60 mg, 0.166 mmol) in 8 mL of dichloromethane. To the resulting solution was added / V-hydroxysuccinimide (19.1 mg, 0.166 mmol). The reaction was incubated on a shaker for 1 h. Then the reaction was filtered to remove the polymer-bound material. The solution was concentrated via reduced pressure to afford 76 mg of Intermediate 3a (99%yield) as a residue. The material was used as is without further purification. LC / MS for C17H22N4O9S [M+H]+calcd. 459.44 m / z, found 459.19 m / z.

[1034] Intermediate 12: To a stirring solution of Intermediate 3a (180 mg, 0.393 mmol) in 2 mL of DMF was added Intermediate 7a (104.8 mg, 0.374 mmol) at room temperature. Then N-methylmorpholine (82.2 pl, 0.748 mmol) was added. After 16 h, the reaction was concentrated via reduced pressure and purified via prep HPLC to afford 41.4 mg of Intermediate 12 (18% yield) as a white foam. LC / MS for C25H33N7O10S [M+H]+calcd. 624.64 m / z, found 624.71 m / z.

[1035] Intermediate 13: To a stirring solution of Intermediate 3a (157 mg, 0.343 mmol) in 2 mL of DMF was added intermediate 7b (91.6 mg, 0.327 mmol) at room temperature. Then N-methylmorpholine (71.9 pl, 0.654 mmol) was added. After 16 h, the reaction was concentrated via reduced pressure and purified via prep HPLC to afford 67.2 mg of Intermediate 13 (33% yield) as a white foam. LC / MS for C25H33N7O10S [M+H]+calcd. 624.64 m / z, found 624.71 m / z.

[1036] Example 1. Synthesis of Payload Compounds of Formulae 1-1, 1-2 and 1-3

[1037] The compounds of Formulae 1-1, I-2 and I-3 may be made according to Scheme 8.

[1038]

[1039] Scheme 8. Synthesis of Compounds 1-1, 1-2 and I-3

[1040] Intermediate 17: Pyridinium p-toluenesulfonate (PPTS) (12 mg, 0.048 mmol), Intermediate 15 (commercially available, 60 mg, 0.30 mmol) and Intermediate 16 (commercially available, 80 mg, 0.0.3 mmol) were added to a 5 mL capacity vial equipped with a magnetic stir bar. Toluene (4 mL) was added, and the vial was sealed with a septum cap then placed in a heating block set to 105°C and stirred overnight. The vial was removed from the heatingblock and allowed to cool to room temperature. Solids were collected by vacuum filtration then triturated with CH2CI2 (1 mL) while cooling in an ice / water bath. Solids were collected by vacuum filtration then placed under high vacuum for 5 h, giving 60 mg (50% yield) of product, as a solid that was used without further purification. HPLC / LRMS C23H21FN2O5 (M + H)+calcd. 425.1, found 425.2.

[1041] Intermediate 18: Intermediate 17 (26 mg, 0.063 mmol) was added to a 3 mL capacity vial equipped with a magnetic stir bar. 48% hydrobromic acid (2 mL) was added and the vial was sealed under a stream of nitrogen with a septum cap. The vial was placed in a heating block set to 92°C and stirred overnight. The heating block was removed and after 5 min, the septum was carefully punctured with a fine needle to relieve pressure. The hydrobromic acid was carefully removed by rotary evaporation. The residue was then taken up in deionized water, which was then removed by rotary evaporation. The residue was taken up in dichloromethane (10 mL) then toluene (1 mL) was added. Solvent was rotary evaporated, and residue was dissolved again in a minimum volume of dichloromethane then rotary evaporated giving 19 mg (73% yield) of product as a solid. This was used in the next step without purification. HPLC / LRMS C22H19FN2O5 (M + H)+calcd. 411.1, found 411.3.

[1042] Compound 1-1: Intermediate 18 (2 mg, 0.0049 mmol) was weighed into a 3 mL capacity vial equipped with a magnetic stir bar then dissolved in anhydrous DMSO (0.40 mL). 2-bromoethoxy)(tert-butyl)dimethylsilane (Intermediate 19a, commercially available) (6 mg, 0.025 mmol) was added then the vial was sealed with a septum cap. The septum was fit with a nitrogen inlet and an oil bubbler outlet. After stirring under slow nitrogen flow for 5 min, TMG (6.0 pL, 0.048 mmol) was injected into the reaction via a 10 pL syringe. After stirring for 6 h additional 19a (6 pg, ~ 1 mg / pL, 0.025 mmol) and TMG (6.0 pL, 0.048 mmol) were sequentially injected into the vial and the reaction was stirred overnight. The reaction gives the desired silyl protected product, and the silyl group is also slowly removed under the reaction conditions. The vial was cooled in an ice / water bath then acetic acid (25 pL) was injected into the vial. A 12 gram BioTage C18 cartridge equipped with a corresponding samplet was equilibrated with 95:5 deionized water (containing 0.5% formic acid): acetonitrile, flow rate of 11 mL / min. The reaction mixture was injected onto the column then the column was eluted with deionized water (containing 0.5% formic acid) and a linear gradient of 5% - 95% acetonitrile over 20 column volumes. Fractions containing the desired product were combined and solvent was removed by rotary evaporation giving 1.4 mg (63% yield) of product as a solid. HPLC / LRMS C24H23FN2O6 (M + H)+calcd. 455.2, found 455.1.Compound 1-2: Prepared similarly to Compound 1-1, using Intermediate 18 and (3-bromopropoxy)(tert-butyl)dimethylsilane (Intermediate 19b, commercially available), (54% yield). HPLC / LRMS C25H25FN2O6 (M + H)+calcd. 469.2, found 469.3.

[1043] Compound I-3: Prepared similarly to Compound 1-1, using Intermediate 18 and (4-bromobutoxy)(tert-butyl)dimethylsilane (Intermediate 19c, commercially available), (68% yield). HPLC / LRMS C26H27FN2O6 (M + H)+calcd. 483.2, found 483.2.Example 2. Synthesis of Payload Compounds of Formulae 1-4 through 1-9

[1044] Compounds of formulae 1-4 through 1-9 may be made according to Scheme 9.

[1045]

[1046] Scheme 9. Synthesis of Compounds I-4, 1-5, 1-6, 1-7, 1-8 and I-9Example 3. Synthesis of Linker-Payload Conjugates of Formula 11-1 through 11-9

[1047] Compounds of formulae 11-1 through II-9 may be made according to Scheme 10.

[1048]

[1049] Scheme 10. Synthesis of Compounds 11-1, II-2, II-3, II-4, II-5, II-6, II-7, II-8 and II-9The synthesis of Compound 11-1 is shown in Scheme 11 and described below.

[1050]

[1051] Scheme 11

[1052] Intermediate 20a: Intermediate 10 (140 mg, 0.38 mmol) and Compound 1-1 (113 mg, 0.25 mmol) were weighed into a 20 mL flask equipped with a magnetic stir bar. To which was

[1053] added anhydrous DMSO (3.0 mL) and boron trifluoride diethyl etherate (100 pL, 0.81 mmol) at room temperature. The reaction was stirred overnight. A 30 gram BioTage C18 cartridge equipped with a corresponding samplet was equilibrated with 95:5 deionized water

[1054] (containing 0.5% formic acid): acetonitrile, flow rate of 24 mL / min. Deionized water (0.2 mL) was added to the reaction and after the solution was injected onto the column then eluted

[1055] with deionized water (containing 0.5% formic acid) with a linear gradient of 5% - 95%

[1056] acetonitrile over 20 column volumes. Fractions containing the desired product were

[1057] combined and solvent was removed by rotary evaporation to give 107 mg (56% yield) of

[1058] product as a solid. HPLC / LRMS C42H39FN4O9 (M + H)+calcd. 763.3, found 763.4.

[1059] Intermediate 21a: Intermediate 20a (80 mg, 0.105 mmol) was weighed into a small vial equipped with a magnetic stir bar. Anhydrous THF (2 mL) was added to the vial followed by

[1060] TMG (30 pL, 0.26 mmol), then stirred at room temperature for 2 h. The resulting suspension was transferred to small test tubes and centrifuged to pellet solids. Supernatant was

[1061] removed using a pipette then solids were resuspended by addition of anhydrous THF (1

[1062] mL). The suspension was centrifuged and supernatant was removed. The test tubes were placed in a vial that was put under high vacuum to remove residual solvent, giving 23.8 mg

[1063] (76% yield) of product. HPLC / LRMS C27H29FN4O7 (M + H)+calcd. 541.2, found 541.2.

[1064] Compound 11-1: Intermediates 21a (13 mg, 0.025 mmol) and 6 (17 mg, 0.026 mmol) were dissolved in a solution of 85:15 DMF: water (1.0 mL) and TEA (20 pL, 0.14 mmol). To

[1065] which, DMTMM (20 mg, 0.072 mmol) was added and stirred at room temperature for 30 min.

[1066] A 30 gram BioTage C18 cartridge equipped with a corresponding samplet was equilibrated

[1067] with 95:5 deionized water (containing 0.5% formic acid): acetonitrile, flow rate of 24 mL / min.The reaction mixture was injected onto the column then eluted with deionized water (containing 0.5% formic acid) and a linear gradient of 5% - 65% acetonitrile over 32 column volumes. Fractions containing the desired product were combined and solvent was removed by rotary evaporation to give 7.5 mg (25% yield) of product as a solid. HPLC / LRMS C57H79FN10O15S (M + H)+calcd.1195.5, found 1195.5.

[1068] The synthesis of Compound II-4 is shown in Scheme 10 and described below.

[1069] Compound II-4: Intermediate 21a (18.5 mg, 0.034 mmol) and Intermediate 8 (28 mg, 0.045 mmol, 1.3 eq) were dissolved in 85:15 DMF:deionized water (1 mL) to which DMTMM (17 mg, 0.062 mmol, 1.8 eq) and triethylamine (27 pL, 0.194 mmol, 5.7 eq) were added and stirred at room temperature for 10 min. LIPLC analysis indicated complete reaction. A 30 g biotage C18 column equipped with a corresponding C18 samplet was equilibrated with 3 CV of 95:5 deionized water (0.1% formic acid): acetonitrile at a flow rate of mL / min. The reaction mixture was injected onto the column then the column was run at 5% acetonitrile for 3 CV followed by a linear gradient of 5% - 60% acetonitrile over 24 CV. Fractions containing desired product 90% pure or higher by LIPLC were combined, pool LIPLC purity 95+%, and solvent was removed by rotary evaporation with a bath temperature of 23 °C. Residue was put under high vacuum for 5 h giving 16.6 mg of product as a solid (42 % yield).

[1070] HPLC / LRMS C53H61FN10O16S (M + H)+ calcd. 1145.4, found 1145.5.

[1071] Compounds of formulae II-28 through II-39 may be made by methods analogous to those shown in Scheme 10.

[1072] Intermediates 12 and 13 are expected to react with Intermediates 21a, 21b, and 21c in a manner analogous to those shown in Scheme 10 for Intermediates 6, 8, and 9. Thus, compounds of formula II-40 and 11-41 may be made by methods analogous to those described herein.Example 4. Synthesis of Linker-Payload Conjugates of Formula 11-10 through 11-18

[1073] Compounds of formulae 11-10 through 11-18 may be made according to Scheme 12.

[1074]

[1075] Scheme 12. Synthesis of Compounds 11-10, 11-1, 11-12, 11-13, 11-14, 11-15, 11-16, 11-17 and 11-18Example 5. Synthesis of Linker-Payload Conjugates of Formula 11-19 through 11-27

[1076] Compounds of formulae 11-19 through II-27 may be made according to Scheme 13.

[1077]

[1078] Scheme 13. Synthesis of Compounds 11-19, II-20, 11-21, II-22, II-23, II-24, II-25, II-26, and II-27Example 6. Synthesis of Binding Molecule- Linker- Payload Conjugates (Antibody-Drug Conjugates, ADCs) of Formula (III)

[1079] A method for preparing antibody-drug conjugates involves the coupling of a linker-payload to reduced, inter-chain disulfide-forming cysteine residues of an antibody. The method is shown generally in Method 3 above, and specifically below using the compound of formula 11-1 as an example. By way of example, the antibody may be sacituzumab or trastuzumab.

[1080]

[1081] The antibody is first reduced at a concentration of 2.0-20 mg / mL using a 5.5 molar equivalent of tris(2-carboxyethyl)phosphine hydrochloride (TCEP) in a reduction buffer comprising 20 mM potassium phosphate (K-Pi), 150 mM sodium chloride (NaCI), and 1 mM ethylenediaminetetraacetic acid (EDTA), adjusted to pH 6.9. The reduction reaction is performed at 37°C for 90 minutes to ensure complete reduction of disulfide bonds.

[1082] Following reduction, a linker-payload solution, prepared ata concentration of approximately 20 mM in dimethyl sulfoxide (DMSO) or dimethylacetamide (DMA), is added slowly to the reduced antibody at a molar excess of 9.6. The final concentration of DMSO or DMA in the reaction mixture is maintained at 5-10% of the total reaction volume. The reaction mixture is thoroughly mixed and incubated at room temperature (RT) for 2 hours to facilitate conjugation.

[1083] Upon completion of the conjugation reaction, the resulting antibody-drug conjugate (ADC) is purified to remove excess unreacted linker-payload. This purification step is carried out using either tangential flow filtration (TFF) or gel filtration, depending on the scale of theconjugation reaction. The purified ADC is formulated into a buffer comprising 20 mM histidine, 120 mM sodium chloride, 50 mM sucrose, and 0.02% polysorbate 20, adjusted to pH 6.0. The formulated ADC is subsequently filtered through a 0.2 pm filter under sterile conditions.

[1084] The resulting ADC is typically monomeric and achieves a drug-to-antibody ratio (DAR) of approximately 8 under these conditions. The ADC is characterized by the following methods:

[1085] • Protein concentration is determined by bicinchoninic acid (BCA) protein assay.

[1086] • Aggregation is assessed using size-exclusion chromatography (SEC).

[1087] • Drug-to-antibody ratio (DAR) is quantified using liquid chromatography-mass spectrometry (LC-MS).

[1088] • Residual free drug is measured using reverse-phase high-performance liquid chromatography (RP-HPLC).

[1089] For applications requiring a lower DAR, the molar equivalents of TCEP and linker-payload can be titrated down to achieve the desired level of conjugation.

[1090] Example 7. Synthesis of Payload Compounds of Formula 1-14

[1091] The compounds of Formula 1-14 may be made according to Scheme 14.

[1092]

[1093] Scheme 14. Synthesis of Compound 1-14

[1094] Intermediate 40: Tert-Butyl dimethylsilyl protected mercaptoethanol (108 mg, 0.56 mmol, commercially available), was added to a solution of Intermediate 39 (99 g, 0.46 mmol, commercially available) and anhydrous DMF (2.3 mL) were added to a vial equipped with a magnetic stir bar and vigorously stirred at room temperature as potassium carbonate (128mg, 1.36 mmol) was added. After 1 hour the reaction was extracted with 10% aqueous citric acid (20 mL) and Ethyl acetate (2 x 20 mL). The organic phase was concentrated by rotary evaporation. A 12 g Biotage silica column equipped with a corresponding samplet was equilibrated with hexanes at a flow rate of 12 mL / min, 220 nm detection. Concentrate was dissolved in minimum volume of EtOAc and loaded onto the column eluting with 5a linear gradient of ethyl acetate 2% - 10% over 25 column volumes. Fractions containing the desired product were combined and solvent was removed by rotary evaporation to give 170 mg (100% yield) of product as an off white solid. HPLC / LRMS C11H12FNO4S (M + H)+calcd.

[1095] 388.1, found 288.2.

[1096] Intermediate 41: Intermediate 40 (114.5 mg, 0.296 mmol) was weighed into a vial equipped with a magnetic stir bar to which a solution of ammonium chloride (11.9 mg, 0.22 mmol) in deionized water (0.6 mL) and ethanol (1.2 mL) was added followed by iron powder (99.4 g, 1.78 mmol). The flask was fit with a septum and placed under positive nitrogen pressure while stirring in a heating block that was set to 90 °C. After 30 min 2 M HCI (250 uL) was added, stirred for 1 h then deionized water (10 mL) was added and the pH was brought to 5 using sat NaHCCh. The mixture was extracted with ethyl acetate (2 x 40 mL), washed with brine (5 mL) and dried over anhydrous sodium sulfate, filtered then evaporated to give 40 mg (56% yield) of product as semi-solid. HPLC / LRMS Cn^eFNCLSSi (M + H)+calcd. 388.1, found 388.4.

[1097] Compound 1-14: Pyridinium p-toluenesulfonate (PPTS, 5.4 mg, 21.6 mmol), Intermediate 41 (51.5 g, 0.21 mmol) and Intermediate 16 (57.9 g, 0.22 mmol, commercially available) were added to a small vial equipped with a magnetic stir bar. Toluene (1.3 mL) was added, and the vial was sealed with a pressure release septum cap then placed in a heating block set to 100 °C then stirred for 48 h. The vial was removed from the heating block, allowed to cool to room temperature and vortexed. The suspension was centrifuged, supernatant was removed then Toluene (1 mL) was added, mixed and centrifuged. Supernatant was removed then acetonitrile (0.5 mL) was added, triturated and centrifuged. Supernatant was removed and solids was dried under high vacuum for 5 h to give 16.9 mg (17 % yield) of slightly yellow solid. HPLC / LRMS C24H23FN2O5S (M + H)+calcd. 471.1, found 471.3.

[1098] Example 8. Synthesis of Payload Compounds of Formula 1-15

[1099] The compounds of Formula 1-15 may be made according to Scheme 15.

[1100]

[1101] Scheme 15. Synthesis of Compound 1-15

[1102] Intermediate 17a: Pyridinium p-toluenesulfonate (PPTS) (12 mg, 0.048 mmol), Intermediate 15a (57 mg, 0.30 mmol, commercially available) and Intermediate 16 (80 mg, 0.0.3 mmol, commercially available) were added to a 5 mL capacity vial equipped with a magnetic stir bar. Toluene (4 mL) was added, and the vial was sealed with a septum cap then placed in a heating block set to 105°C and stirred overnight. The vial was removed from the heating block and allowed to cool to room temperature. Solids were collected by vacuum filtration then triturated with CH2CI2 (1 mL) while cooling in an ice / water bath. Solids were collected by vacuum filtration then placed under high vacuum for 5 h to afford 52 mg of Intermediate 17a (48% yield) as a solid that was used without further purification. LC / MS for C22H19FN2O5 [M + H]+calcd. 397.2 m / z, found 397.3 m / z.

[1103] Intermediate 18a: Intermediate 17a (24 mg, 0.061 mmol) was added to a 3 mL capacity vial equipped with a magnetic stir bar. 48% hydrobromic acid (2 mL) was added and the vial was sealed under a stream of nitrogen with a septum cap. The vial was placed in a heating block set to 92°C and stirred overnight. The heating block was removed and after 5 min, the septum was carefully punctured with a fine needle to relieve pressure. The hydrobromic acid was carefully removed by rotary evaporation. The residue was then taken up in deionized water, which was then removed by rotary evaporation. The residue was taken up in dichloromethane (10 mL) then toluene (1 mL) was added. Solvent was rotary evaporated, and residue was dissolved again in a minimum volume of dichloromethane then rotary evaporated to afford 17 mg of Intermediate 18a (71% yield) as a solid. The material was used in the next step without purification. HPLC / LRMS C21H17FN2O5 [M+H]+calcd. 411.1 m / z, found 411.3 m / z.

[1104] Compound 1-15: Intermediate 18a (6 mg, 0.015 mmol) was weighed into a 3 mL capacity vial equipped with a magnetic stir bar then dissolved in anhydrous DMSO (0.60 mL). 2-bromoethoxy)(tert-butyl)dimethylsilane (18 mg, 0.075 mmol, commercially available) was added then the vial was sealed with a septum cap. The septum was fit with a nitrogen inlet and an oil bubbler outlet. After stirring under slow nitrogen flow for 5 min, TMG (18.0 pL, 0.14 mmol) was injected into the reaction via a 10 pL syringe. After stirring for 6 h additional 2-bromoethoxy)(tert-butyl)dimethylsilane (6 pg, ~ 1 mg / pL, 0.025 mmol) and TMG (6.0 pL, 0.14 mmol) were sequentially injected into the vial and the reaction was stirred overnight. The reaction gives the desired silyl protected product, and the silyl group is also slowly removed under the reaction conditions. The vial was cooled in an ice / water bath then acetic acid (75 pL) was injected into the vial. A 12 gram BioTage C18 cartridge equipped with a corresponding samplet was equilibrated with 95:5 deionized water (containing 0.5% formic acid): acetonitrile, flow rate of 11 mL / min. The reaction mixture was injected onto the column then the column was eluted with deionized water (containing 0.5% formic acid) and a linear gradient of 5% - 95% acetonitrile over 20 column volumes. Fractions containing the desired product were combined and solvent was removed by rotary evaporation to afford 5 mg of compound 1-15 (75 % yield) as a solid. LC / MS forC23H2iFN2Oe [M+H]+calcd. 441.2 m / z, found 441.3 m / z.Example 9. Synthesis of Linker-Payload Conjugates of Formula 11-42 through 11-46

[1105] Compounds of formulae 11-42 through 11-46 may be made according to Scheme 16.

[1106]

[1107] Scheme 16. Synthesis of Compounds II-42, 11 -43, II-44, 11 -45, and II-46The synthesis of Compounds 11-43 and 11-45 is shown in Scheme 16 and described below.

[1108] Intermediate 42: Intermediate 10 (40.7 mg, 0.11 mmol, commercially available) and Compound 1-14 (40 mg, 0.085 mmol) were weighed into a vial equipped with a magnetic stir bar. To which was added anhydrous DMSO (1.0 mL) and boron trifluoride diethyl etherate (28 pL, 0.22 mmol) at room temperature and stirred overnight. A 12 gram BioTage C18 flash cartridge equipped with a corresponding samplet was equilibrated with 95:5 deionized water (containing 0.5% formic acid): acetonitrile, flow rate of 10 mL / min. The solution was quickly injected onto the column, which was eluted with 95:5 deionized water (containing 0.5% formic acid): acetonitrile 3 column volumes then with a linear gradient of 5% - 95% acetonitrile over 22 column volumes. Fractions containing the desired product were combined and solvent was removed by rotary evaporation to give 37 mg (56 % yield) of product as a solid. HPLC / LRMS C41H37FN4O9 (M + H)+calcd. 749.3, found 749.2.

[1109] Intermediate 43: Intermediate 42 (44 mg, 0.057 mmol) was weighed into a small vial equipped with a magnetic stir bar. Anhydrous THF (0.9 mL) was added to the vial followed by DBU (9.0 pL, 0.057 mmol), then stirred at room temperature for 2 h. The resulting suspension was centrifuged, supernatant removed then THF (0.5 mL) was added, triturated and centrifuge. Supernatant was removed and solid was placed under high vacuum for 4 h to give 25 mg (80 % yield) of product. HPLC / LRMS C27H29FN4O6S (M + H)+calcd. 557.2, found 557.1.

[1110] Compound II-43: Intermediate 43 (21 mg, 0.037 mmol) and Intermediate 8 (40 mg, 0.06 mmol) were dissolved in a solution of 85:15 DMSO: water (0.75 mL) and TEA (44 pL, 0.316mmol). To which, DMTMM (22 mg, 0.080 mmol) was added and stirred at room temperature for 30 min. A 12 gram BioTage C18 flash cartridge equipped with a corresponding samplet was equilibrated with 95:5 deionized water (containing 0.5% formic acid): acetonitrile, flow rate of 10 mL / min. The reaction mixture was injected onto the column then eluted with deionized water (containing 0.5% formic acid) and a linear gradient of 5% -85% acetonitrile over 32 column volumes. Fractions containing the desired product were combined and solvent was removed by rotary evaporation to give 16 mg (37 % yield) of product as a solid. HPLC / LRMS C53H61FN10O15S (M + H)+calcd.1161.4, found 1161.2. Compound II-45: Intermediate 43 (22 mg, 0.039 mmol) and Intermediate 12 (25 mg, 0.04 mmol) were dissolved in a solution of DMSO (0.50 mL) and DIPEA (14 pL, 0.08 mmol). To which, HATU (25.8 mg, 0.068 mmol) was added and stirred at room temperature for 50 min. A 12 gram BioTage C18 flash cartridge equipped with a corresponding samplet was equilibrated with 95:5 deionized water (containing 0.5% formic acid): acetonitrile, flow rate of 10 mL / min. The reaction mixture was injected onto the column then eluted with deionizedwater (containing 0.5% formic acid) and a linear gradient of 5% - 85% acetonitrile over 32 column volumes. Fractions containing the desired product were combined and solvent was removed by rotary evaporation to give 10 mg (27 % yield) of product as a solid.

[1111] HPLC / LRMS C52H59FN10O16S (M + H)+calcd.1148.4, found 1148.6.

[1112] Compounds of formulae II-42, II-44, and II-46 may be made by methods analogous to those described herein.Example 10. Synthesis of Linker-Payload Conjugates of Formula 11-47 through 11-51

[1113] Compounds of formulae II-47 through 11-51 may be made according to Scheme 17.

[1114]

[1115] Scheme 17. Synthesis of Compounds II-47, II-48, II-49, II-50, and 11-51The synthesis of Compounds 11-47, 11-48, and 11-50 is shown in Scheme 17 and described below.

[1116] Intermediate 44: Intermediate 10 (13 mg, 0.035 mmol, commercially available) and Compound 1-15 (13 mg, 0.029 mmol) were weighed into vial equipped with a magnetic stir bar. To which was added anhydrous DMSO (0.25 mL) and boron trifluoride diethyl etherate (6.8 pL, 0.055 mmol, 1.94 eq) at room temperature. The reaction was stirred overnight. A 12 gram BioTage C18 flash cartridge equipped with a corresponding samplet was equilibrated with 95:5 deionized water (containing 0.5% formic acid): acetonitrile, flow rate of 45 mL / min. Approximately half of the reaction mixture was transferred to a scintillation vial and 1:1 DMSO: Deionized water (0.2 mL) was added to it then vortexed for 1 min. The solution was quickly injected onto the column, which was eluted with 95:5 deionized water (containing 0.5% formic acid): acetonitrile 3 column volumes then with a linear gradient of 5% - 95% acetonitrile over 24 column volumes. The process was repeated for the other -half of the reaction solution. Fractions containing the desired product were combined and solvent was removed by rotary evaporation to give 12 mg (57% yield) of product as a solid. HPLC / LRMS C41H37FN4O9 (M + H)+calcd. 749.3, found 749.2.

[1117] Intermediate 45: Intermediate 44 (10.3 mg, 0.020 mmol) was weighed into a small vial equipped with a magnetic stir bar. Anhydrous THF (0.3 mL) was added to the vial followed by DBU (2.7 pL, 1.82 mmol, 0.93 eq), then stirred at room temperature for 2 h. The resulting suspension was vacuum filtered and washed with anhydrous THF (0.3 mL). Solid was placed under high vacuum for 4 h to give 8.5 mg (82.6 % yield) of product. HPLC / LRMS C26H27FN4O7 (M + H)+calcd. 527.2, found 527.4.

[1118] Compound II-47: DIPEA (150 pL, 0.862 mmol) was added to a mixture of Intermediate 6 (140.74 mg, 0.209 mmol), Intermediate 45 (130 mg, 0.247 mmol) and HATU (123 mg, 0.323 mmol) in DMSO (2.8 mL) was added. The resulting mixture was stirred at room temperature for 40 min. The reaction mixture was directly purified with reverse chromatography using 25-35% MeCN / water (both having 0.1% formic acid, 30 g) to afford 88.8 mg (36% yield) of Compound 11-51 as a solid. LCMS for C56H77FN10O15S [M+H]+calcd. 1181.4 m / z, found 1181.2.

[1119] Compound II-48: DI PEA (20 pL, 0.115 mmol) was added to a mixture of Intermediate 8 (16.55 mg, 0.027 mmol), Intermediate 45 (13.2 mg, 0.025 mmol) and HATU (20.96 mg, 0.055 mmol) in DMSO (0.5 mL) was added. The resulting mixture was stirred at room temperature for 45 min. The reaction mixture was directly purified with reverse chromatography using 25-40% MeCN / water (both having 0.1% formic acid) (12 g column) toafford 5.97 mg (21% yield) of Compound II-52 as a solid. LCMS for C52H59FN10O16S [M+H]+calcd. 1131.3 (MIT), found 1131.6.

[1120] Compound II-50: DI PEA (22 pL, 0.126 mmol) was added to a mixture of Intermediate 12 (19.42 mg, 0.031 mmol), Intermediate 45 (19.09 mg, 0.036 mmol) and HATLI (25.82 mg, 0.068 mmol) in DMSO (0.7 mL) was added. The resulting mixture was stirred at room temperature for 35 min. The reaction mixture was directly purified with reverse chromatography using 10-35% MeCN / water (both having 0.1% formic acid) to afford 15.3 mg (43% yield) of Compound II-50 as a solid. LCMS for CsiHssFNnOieS [M+H]+calcd. 1132.4 (MIT), found 1132.4.

[1121] Compounds of formulae II-49 and 11-51 may be made by methods analogous to those described herein.

[1122] Example 11. Synthesis of Binding Molecule- Linker- Payload Conjugates of Formula 111-1 through 111-15

[1123] A method for preparing antibody-drug conjugates involves the coupling of a linker-payload to reduced, inter-chain disulfide-forming cysteine residues of an antibody. In the compounds of formulae 111-1 through 111-15, the antibody is trastuzumab.

[1124] The antibody was first reduced at a concentration of 2.0-8.0 mg / mL using a 5.5 molar equivalent of tris(2-carboxyethyl)phosphine hydrochloride (TCEP) in a reduction buffer comprising 20 mM potassium phosphate (K-Pi), 150 mM sodium chloride (NaCI), and 1 mM ethylenediaminetetraacetic acid (EDTA), adjusted to pH 6.9. The reduction reaction was performed at 37°C for 90 minutes to ensure complete reduction of disulfide bonds.

[1125] Following reduction, a linker-payload solution, prepared at a concentration of approximately 20 mM in dimethyl sulfoxide (DMSO) or dimethylacetamide (DMA), was added slowly to the reduced antibody at a molar excess of 10-20. The final concentration of DMSO or DMA in the reaction mixture was maintained at 10% of the total reaction volume. The reaction mixture was thoroughly mixed and incubated at room temperature (RT) for 2 hours to facilitate conjugation.

[1126] Upon completion of the conjugation reaction, the resulting antibody-drug conjugate (ADC) was purified to remove excess unreacted linker-payload by gel filtration. The purified ADCwas formulated into a buffer comprising 20 mM histidine, 120 mM sodium chloride, 50 mM sucrose, and 0.02% polysorbate 20, adjusted to pH 6.0. The formulated ADC was subsequently filtered through a 0.2 pm filter under sterile conditions.

[1127] The resulting ADC is typically monomeric and achieves a drug-to-antibody ratio (DAR) of approximately 8 under these conditions. The ADC is characterized by the following methods:

[1128] • Protein concentration is determined by bicinchoninic acid (BCA) protein assay.

[1129] Aggregation is assessed using size-exclusion chromatography (SEC).

[1130] • Drug-to-antibody ratio (DAR) is quantified using liquid chromatography-mass spectrometry (LC-MS).

[1131] • Residual free toxin is measured using reverse-phase high-performance liquid chromatography (RP-HPLC).

[1132] The characterisation of the ADCs of Formula 111-1, HI-2, HI-6, HI-7, and HI-9 is summarised in Table 4.

[1133] <

[1134] <

[1135] <

[1136] <

[1137] <

[1138]

[1139] Table 4

[1140] Biological Example 1. Cytotoxicity of Payload Compounds of Formula 1-1, 1-2 and 1-3

[1141] The cell lines utilized in the cytotoxicity studies, including PA-1, OVCAR3, HCC1806, BxPC-3, and SK-BR-3, were obtained from the American Type Culture Collection (ATCC) and cultured according to ATCC-recommended protocols.

[1142] For the cytotoxicity assays, the test cell lines were seeded into 96-well culture microplates.

[1143] Following overnight incubation, the cells were exposed to a series of payload concentrations for 72 hours. The cytotoxic effect of the payloads on cell viability was assessed using the CellTiter-Glo Luminescent Cell Viability Assay (Promega), a widely used method that quantifies viable cells by measuring ATP levels in metabolically active cells, following the protocol provided by the manufacturer.The surviving fraction was determined by dividing the luminescence signal from wells treated with the payload by the luminescence signal from untreated control wells. These data were used to construct dose-response curves, and the half-maximal inhibitory concentration (IC50) values were calculated using a four-parameter variable slope model with GraphPad Prism software.

[1144] The cytotoxicity of the tested payloads of Formula 1-1, I-2 and I-3, was evaluated relative to Dxd (MedChemExpress), the structure of which is shown below, which was included as a benchmark due to its well-characterized potency.

[1145]

[1146] The results are shown in Figures 1 to 6 and in Table 5 expressed as IC50 in nM.

[1147]

[1148] Table 5

[1149] Across all tested tumour cell lines (PA-1, OVCAR3, HCC1806, BxPC-3, and SK-BR-3), Dxd demonstrated IC50 values ranging from sub-nanomolar to double-digit nanomolar concentrations. Similarly, the payloads of Formula 1-1, I-2 and I-3 all exhibited cytotoxic activity comparable to Dxd. Among the payloads, 1-1 demonstrated the greatest potency, followed by I-2, which exhibited slightly lower potency, and I-3, which showed approximately two fold lower potency than 1-1 across all cell lines.

[1150] Biological Example 2. Cytotoxicity of Binding Molecule- Linker- Payload Conjugates of Formula 111-1, 111-2, 111-6, 111-7, and 111-9

[1151] The cell line SK-BR-3 utilized in the cytotoxicity studies, was obtained from the American Type Culture Collection (ATCC) and cultured according to ATCC-recommended protocols.For the cytotoxicity assays, SK-BR-3 cells were seeded into 96-well culture microplates. Following overnight incubation, the cells were exposed to a series of ADC concentrations for 120 hours. The cytotoxic effect of the ADCs on cell viability was assessed using the CellTiter-Glo Luminescent Cell Viability Assay (Promega), a widely used method that quantifies viable cells by measuring ATP levels in metabolically active cells, following the protocol provided by the manufacturer.

[1152] The surviving fraction was determined by dividing the luminescence signal from wells treated with the ADCs by the luminescence signal from untreated control wells. These data were used to construct dose-response curves, and the half-maximal inhibitory concentration (IC50) values were calculated using a four-parameter variable slope model with GraphPad Prism software.

[1153] The results are shown in Figures 6 and 7 and in Table 6.

[1154]

[1155] Table 6

[1156] As shown in Table 6, all ADCs exhibited IC50 values in the sub-nanomolar range.

[1157] All publications mentioned in the above specification are herein incorporated by reference.

[1158] Various modifications and variations of the described methods and system of the present invention will be apparent to those skilled in the art without departing from the scope and spirit of the present invention. Although the present invention has been described in connection with specific preferred embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. Indeed, various modifications of the described modes for carrying out the invention which are obvious to

[1159] those skilled in chemistry, biochemistry, molecular biology, biotechnology or related fields are intended to be within the scope of the following claims.

Claims

Claims1. A compound of formula (l-Y):or a pharmaceutically acceptable salt or solvate thereof,wherein:II is O or S;X is O, S, S(=O) or S(=O)2;A is C2-10 alkylene, C2-10 alkenylene, C2- alkynylene, C3-10 cycloalkylene, C3-10 cycloalkenylene, Cs- cycloalkynylene, C3-10 heterocycloalkylene, C3-10 heterocycloalkenylene, or Cs- heterocycloalkynylene, each optionally substituted with one or more substituents selected from List 1 ;either: R1 is C1-6 alkyl or C3-6 cycloalkyl, and R4 is H, C1-6 alkyl or C3-6 cycloalkyl, or: R1 and R4 together with the carbon atoms to which they are attached form a 5- to 7-membered carbocyclic ring which is substituted by a group -NH-C(=O)-Rs;R2 is halogen or C1-6 alkyl;R3 is C1-6 alkyl; andRs is C1-6 alkyl or-NR’R”, wherein R’ and R” are each independently H or C1-6 alkyl; provided that when X is O and R1 is ethyl, A is not C2-3 alkylene.

2. A compound according to claim 1, wherein R1 is methyl3. A compound according to claim 1 to claim 2 wherein X is O.

4. A compound according to claim 1 , wherein X is S.

5. A compound according to any one of claims 1 to 4, wherein II is O.

6. A compound according to any one of claims 1 to 4, wherein II is S.

7. A compound according to any one of claims 1 to 6, wherein A is C2-6 alkylene.

8. A compound according to claim 7, wherein A is C2-4 alkylene.

9. A compound according to any one of claims 1 to 6, wherein A is C3-6 cycloalkylene.

10. A compound according to any one of claims 1 to 9, wherein R2 is halogen.

11. A compound according to claim 10, wherein R2 is F.

12. A compound according to any one of claims 1 to 11 , wherein R3 is ethyl.

13. A compound according to any one of claims 1 or 3 to 12, wherein R1 is ethyl.

14. A compound according to any one of claims 1 to 13, wherein R4 is H.

15. A compound according to any one of claims 1 or 3 to 12, of formula (IA):wherein:II, X, A, R2, R3, and Rs are as defined in any one of claims 1 to 11 ;n is 0, 1, or 2; andm is 0, 1 or 2, with the proviso that m+n must be 1 , 2 or 3.

16. A compound according to claim 1, selected from the group consisting of:or a pharmaceutically acceptable salt or solvate thereof.

17. A compound of formula (ll-YY):or a pharmaceutically acceptable salt or solvate thereof,wherein:X, II, A, Ri, R2, R3, R4 and Rs are as defined in any one of claims 1 to 16;L is a linker; andY is a group capable of conjugating with a binding molecule to generate a conjugate.

18. A compound of formula (ll-Y):or a pharmaceutically acceptable salt or solvate thereof,wherein:II is O or S;X is a bond, O, S, S(=O) or S(=O)2;when X is O, S, S(=O) or S(=O)2, A is C2-10 alkylene, C2-10 alkenylene, C2- alkynylene, C3-10 cycloalkylene, C3-10 cycloalkenylene, Cs- cycloalkynylene, C3-10 heterocycloalkylene, C3-10heterocycloalkenylene, or Cs- heterocycloalkynylene, each optionally substituted with one or more substituents selected from List 1 ;when X is a bond, A is C1-10 alkylene, C2-10 alkenylene, C2- alkynylene, C3-10 cycloalkylene, C3-10 cycloalkenylene, Cs- cycloalkynylene, C3-10 heterocycloalkylene, C3-10 heterocycloalkenylene, or Cs- heterocycloalkynylene, each optionally substituted with one or more substituents selected from List 1 ;R1 and R4 are each independently H, or C1-6 alkyl or C3-6 cycloalkyl;or: R1 and R4 together with the carbon atoms to which they are attached form a 5- to 7-membered carbocyclic ring which is substituted by a group -NH-C(=O)-Rs;R2 is H, halogen or C1-6 alkyl;R3 is C1-6 alkyl; andRs is C1-6 alkyl or-NR’R”, wherein R’ and R” are each independently H or C1-6 alkyl;L is a linker of formula (LX”):> >>wherein:R is C1-6 alkyl;EO is an ethylene glycol moiety, the terminal carbon of which is attached to the group -N(R)-and the terminal oxygen of which is attached to the group -(CH2)W- when w is 1 to 10, or to the - C(=O) group when w is 0;v is 0 or 1 to 40;w is 0 or 1 to 10;P is a peptide moiety consisting of 1 to 10 amino acid residues;Re and R7 are each independently H or C1-6 alkyl, or Re and R7 together with the carbon atom to which they are attached form a 3- to 10-membered carbocyclic ring;position (1) is bonded to the group Y; andposition (2) is bonded to the U atom of the -L-U- moiety; andY is a group capable of conjugating with a binding molecule to generate a conjugate.

19. A compound according to claim 18, wherein R is methyl.

20. A compound according to claim 18 or 19, wherein P consists of 1 to 6 amino acid residues.

21. A compound according to any one of claims 18 to 20, wherein P comprises any of AA1, AA1-Gly, Val-Cit, Val-Ala, Val-AA1, Val-AA1-Gly, AA1-Ala-Asn, Ala-Ala-Ala, Ala-Ala-Asn, Glu- Val-Cit, Glu-Val-AA1, Glu-Glu, Glu-Gly-Cit, Glu-Gly-AA1, or Gly-Gly- AA1-Gly (GGFG) where AA1represents any amino acid residue.

22. A compound according to any one of claims 18 to 21 , wherein P comprises any of AA1, AA1-Gly, Val-Cit, Val-Ala, Val-AA1, Val-AA1-Gly, AA1-Ala-Asn, Ala-Ala-Ala, Ala-Ala-Asn, Glu- Val-Cit, Glu-Val-AA1, Glu-Glu, Glu-Gly-Cit, Glu-Gly-AA1, Gly-Gly-Phe-Gly (GGFG) or Gly- Gly-Pya-Gly, where AA1represents any amino acid residue and Pya represents a (2- pyridyl)alanine, (3-pyridyl)alanine or (4-pyridyl)alanine residue.

23. A compound according to claim 21 or 22, wherein the amino acid residue represented24. A compound according to claim 21 or 22, wherein P comprises Val-AA1-Gly, where AA125. A compound according to claim 21 or 22, wherein P comprises a GGFG peptide moiety.

26. A compound according to claim 21 or 22, wherein P comprises a GG(Pya)G peptide moiety wherein Pya represents a (2-pyridyl)alanine, (3-pyridyl)alanine or (4-pyridyl)alanine residue.

27. A compound according to any one of claims 18 to 26, wherein v is 2.

28. A compound according to any one of claims 18 to 27, wherein w is 1.

29. A compound according to any one of claims 18 to 28, wherein R6and R7are each independently H.

30. A compound according to claim 17 or 18 wherein L is a group selected from the group consisting of formulae (L1) to (L5), wherein position (1) is bonded to the group Y in formula (ll-Y); and position (2) is bonded to the II atom of the -L-U- moiety in formula (I l-Y):

31. A compound according to claim 17 or 18, wherein L is a group of formula (L1):wherein:position (1) is bonded to the group Y in formula (I l-Y); andposition (2) is bonded to the II atom of the -L-U- moiety in formula (ll-Y).

32. A compound according to claim 17 or 18, wherein L is a group of formula (L2):wherein:position (1) is bonded to the group Y in formula (ll-Y); andposition (2) is bonded to the II atom of the -L-U- moiety in formula (ll-Y).

33. A compound according to claim 17 or 18, wherein L is a group of formula (L3):wherein:position (1) is bonded to the group Y in formula (I l-Y); andposition (2) is bonded to the II atom of the -L-U- moiety in formula (ll-Y).

34. A compound according to claim 17 or 18, wherein L is a group of formula (L4):wherein:position (1) is bonded to the group Y in for mula (ll-Y); andposition (2) is bonded to the U atom of the -L -U- moiety in formula (ll-Y).

35. A compound according to claim 17 or 18, wherein L is a group of formula (L5):wherein:position (1) is bonded to the group Y in formula (ll-Y); andposition (2) is bonded to the II atom of the -L-U- moiety in formula (ll-Y).

36. A compound according to claim 17 or 18, which is a compound of formula 11-1 through II- 51 or a pharmaceutically acceptable salt or solvate thereof:<"">"<> < > " <<""">><>><wherein Ac is -C(=0)-CH3.

37. A compound of formula (lll-Y):or a pharmaceutically acceptable salt or solvate thereof, wherein:BM is a binding molecule or a fragment thereof;X, II, A, L, Ri, R2, R3, R4 and Rs are as defined in claim 17 or claim 18; andq is an integer from 1 to 16.

38. A compound according to claim 37, wherein BM is an antibody or fragment thereof.

39. A compound according to claim 37 or 38, wherein BM specifically binds to a target expressed on the surface of a tumour cell.

40. A compound according to claim 39, wherein the target is selected from B7H3, TROP2, HER2 and HER3.

41. A pharmaceutical composition comprising a compound according to any one of claims 1-40 and a pharmaceutically acceptable carrier.

42. A compound according to any one of claims 1-40 for use in medicine.

43. A compound according to any one of claims 1-40 for use in treating cancer.

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