HIV-1-targeted multabody constructs, compositions, and methods

Abstract

In aspects, fusion polypeptides comprising an HIV-1 binding moiety and a nanocage monomer (e.g., ferritin) or subunit thereof are described herein. In aspects, self-assembled polypeptide complexes comprising such fusion polypeptides are also described, including multispecific self-assembled polypeptide complexes whose HIV-1 binding moieties collectively target more than one epitope on HIV-1.

Description

HIV-1-TARGETED MULTABODY CONSTRUCTS, COMPOSITIONS, AND METHODS CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present application claims benefit of and priority to U.S. Provisional Patent Application No.63 / 582,462 filed September 13, 2023, and U.S. Provisional Patent Application No. 63 / 588,715 filed October 7, 2023, the entire contents of each of which are hereby incorporated by reference for all purposes. SEQUENCE LISTING

[0002] The present specification makes reference to a Sequence Listing which has been submitted electronically in XML format and is hereby incorporated by reference in its entirety. Said XML file, created on September 10, 2024, is named RBT-012_SL.xml and is 146 kilobytes in size. BACKGROUND

[0003] Infection with human immunodeficiency virus (HIV) can lead to acquired immunodeficiency syndrome (AIDS), which results in a gradual and persistent decline and failure of the immune system. Almost one million people die from HIV / AIDS each year, with HIV / AIDS being the leading cause of death in some countries.

[0004] Two main types of HIV have been identified, with HIV type 1 (HIV-1) being more prevalent and pathogenic than HIV-2.

[0005] The major HIV-1 envelope protein (HIV-1 Env) is a glycoprotein of approximately 160 kD (gp160). During infection, proteases of the host cell cleave gp160 into gp120 and gp41. gp41 is an integral membrane protein, while gp120 protrudes from the mature virus. Together gp120 and gp41 make up the HIV-1 envelope spike, which is a target for neutralizing antibodies.

[0006] While neutralizing antibodies exist against the HIV-1 Env, there remains a need for improved anti-HIV therapeutics.SUMMARY

[0007] The present invention addresses this need with the provision of self-assembled polypeptide complexes comprising, among other things, antibody fragments which target the HIV-1 envelope protein (HIV-1 Env).

[0008] In one aspect, provided are self-assembled polypeptide complexes comprising (a) one or more first fusion polypeptides, each first fusion polypeptide comprising (1) an HIV-1- binding moiety linked to (2) a nanocage monomer or subunit thereof; and (b) one or more second fusion polypeptides, each second fusion polypeptide comprising (1) an Fc polypeptide linked to (2) a nanocage monomer or subunit thereof, wherein the self-assembled polypeptide complex exhibits neutralizing activity against HIV-1 with a median IC80below 5 ng / mL.

[0009] In one aspect, provided are self-assembled polypeptide complexes comprising (a) one or more first fusion polypeptides, each first fusion polypeptide comprising (1) an HIV-1- binding moiety linked to (2) a nanocage monomer or subunit thereof; and (b) one or more second fusion polypeptides, each second fusion polypeptide comprising (1) an Fc polypeptide linked to (2) a nanocage monomer or subunit thereof, wherein the self-assembled polypeptide complex is capable of neutralizing at least 98% of the pseudoviruses in a reference HIV-1 pseudovirus panel at an IC80cutoff of < 10 µg / mL.

[0010] In some embodiments, provided self-assembled polypeptide complexes are capable of neutralizing at least 98% of the pseudoviruses in the reference HIV-1 pseudovirus panel at an IC80cutoff of < 1.0 µg / mL.

[0011] In some embodiments, provided self-assembled polypeptide complexes are capable of neutralizing at least 98% of the pseudoviruses in the reference HIV-1 pseudovirus panel at an IC80 cutoff of < 0.1 µg / mL.

[0012] In one aspect, provided are self-assembled polypeptide complexes comprising (a) one or more first fusion polypeptides, each first fusion polypeptide comprising (1) a first HIV-1-binding moiety linked to (2) a nanocage monomer or subunit thereof; (b) one or more second fusion polypeptides, each second fusion polypeptide comprising (1) a second HIV-1- binding moiety linked to (2) a nanocage monomer or subunit thereof; (c) one or more third fusion polypeptides, each third fusion polypeptide comprising (1) a third HIV-1-binding moiety linked to (2) a nanocage monomer or subunit thereof; and (d) one or more fourth fusion polypeptides, each fourth fusion polypeptide comprising (1) an Fc polypeptide linked to (2) a nanocage monomer or subunit thereof, wherein the first, second, and third HIV-1- binding moieties are collectively capable of binding to three different epitope classes of the HIV-1 envelope protein, wherein if two of the HIV-1 binding moieties are fragments ofPDGM1400 and 10E8v4, then none of the HIV-1 binding moieties are fragments of N49P7 or iMab.

[0013] In some embodiments, the first, second, and third HIV-1-binding moieties are collectively capable of binding to the V1 / V2 interface, the V3 glycan, and the CD4 binding site on HIV-1 Env.

[0014] In some embodiments, the first, second, and third HIV-1-binding moieties are collectively capable of binding to the V1 / V2 interface, the membrane-proximal external region (MPER), and the CD4 binding site on HIV-1 Env.

[0015] In one aspect, provided are fusion polypeptides comprising an HIV-1 binding antibody or HIV-1 binding fragment thereof linked to a nanocage monomer or subunit thereof, wherein the HIV-1 binding antibody or HIV-1 binding fragment thereof binds to an epitope selected from the group consisting of the gp140-gp41 interface and the silent face of HIV-1 Env.

[0016] In one aspect, provided are fusion polypeptides comprising an HIV-1-binding antibody or HIV-1 binding fragment thereof linked to a nanocage monomer or subunit thereof, wherein the HIV-1-binding antibody or HIV-1 binding fragment thereof comprises a heavy chain complementarity determining region 3 (CDR-H3) selected from the group consisting of SEQ ID NOs: 53, 61, 69, 77, 85, 93, 101, 109, 117, 125, 133, and 141, or a variant of the foregoing sequences which comprises no more than three, no more than two or no more than one amino acid substitution therefrom.

[0017] In some embodiments, the HIV-1-binding antibody or HIV-1 binding fragment thereof comprises a heavy chain complementarity determining region 3 (CDR-H3) selected from the group consisting of SEQ ID NOs: 53, 61, 69, 77, 85, 93, 101, 109, 117, 125, 133, and 141.

[0018] In some embodiments, the HIV-1-binding antibody or HIV-1 binding fragment thereof comprises a CDR-H3 sequence and a CDR-L3 sequence of (a) SEQ ID NO: 53 and SEQ ID NO: 57, respectively, (b) SEQ ID NO: 61 and SEQ ID NO: 65, respectively, (c) SEQ ID NO: 69 and SEQ ID NO: 73, respectively, (d) SEQ ID NO: 77 and SEQ ID NO: 81, respectively, (e) SEQ ID NO: 85 and SEQ ID NO: 89, respectively, (f) SEQ ID NO: 93 and SEQ ID NO: 97, respectively, (g) SEQ ID NO: 101 and SEQ ID NO: 105, respectively, (h) SEQ ID NO: 109 and SEQ ID NO: 113, respectively,(i) SEQ ID NO: 117 and SEQ ID NO: 121, respectively, (j) SEQ ID NO: 125 and SEQ ID NO: 129, respectively, (k) SEQ ID NO: 133 and SEQ ID NO: 137, respectively, (l) SEQ ID NO: 141 and SEQ ID NO: 145, respectively, or (m) or a CDR-H3 sequence and a CDR-L3 sequence which collectively differ by no more than three, no more than two, or one amino acid substitutions across both CDR-H3 and CDR-L3 sequences of any of the foregoing (a)-(l).

[0019] In some embodiments, the HIV-1-binding antibody or HIV-1 binding fragment thereof comprises a CDR-H3 sequence and a CDR-L3 sequence of (a) SEQ ID NO: 53 and SEQ ID NO: 57, respectively, (b) SEQ ID NO: 61 and SEQ ID NO: 65, respectively, (c) SEQ ID NO: 69 and SEQ ID NO: 73, respectively, (d) SEQ ID NO: 77 and SEQ ID NO: 81, respectively, (e) SEQ ID NO: 85 and SEQ ID NO: 89, respectively, (f) SEQ ID NO: 93 and SEQ ID NO: 97, respectively, (g) SEQ ID NO: 101 and SEQ ID NO: 105, respectively, (h) SEQ ID NO: 109 and SEQ ID NO: 113, respectively, (i) SEQ ID NO: 117 and SEQ ID NO: 121, respectively, (j) SEQ ID NO: 125 and SEQ ID NO: 129, respectively, (k) SEQ ID NO: 133 and SEQ ID NO: 137, respectively, or (l) SEQ ID NO: 141 and SEQ ID NO: 145, respectively.

[0020] In some embodiments, the HIV-1-binding antibody or HIV-1 binding fragment thereof comprises a heavy chain variable region comprising complementarity determining regions CDR-H1, CDR-H2, and CDR-H3, and a light chain variable region comprising complementarity determining regions CDR-L1, CDR-L2, and CDR-L3, having amino acid sequences of (a) SEQ ID NO: 51, 52, and 53 for CDR-H1, CDR-H2, and CDR-H3, respectively and SEQ ID NO: 55, 56, and 57 for CDR-L1, CDR-L2, and CDR-H3, respectively, (b) SEQ ID NO: 59, 60, and 61 for CDR-H1, CDR-H2, and CDR-H3, respectively and SEQ ID NO: 63, 64, and 65 for CDR-L1, CDR-L2, and CDR-H3, respectively, (c) SEQ ID NO: 67, 68, and 69 for CDR-H1, CDR-H2, and CDR-H3, respectively and SEQ ID NO: 71, 72, and 73 for CDR-L1, CDR-L2, and CDR-H3, respectively, (d) SEQ ID NO: 75, 76, and 77 for CDR-H1, CDR-H2, and CDR-H3, respectively and SEQ ID NO: 79, 80, and 81 for CDR-L1, CDR-L2, and CDR-H3, respectively,(e) SEQ ID NO: 83, 84, and 85 for CDR-H1, CDR-H2, and CDR-H3, respectively and SEQ ID NO: 87, 88, and 89 for CDR-L1, CDR-L2, and CDR-H3, respectively, (f) SEQ ID NO: 91, 92, and 93 for CDR-H1, CDR-H2, and CDR-H3, respectively and SEQ ID NO: 95, 96, and 97 for CDR-L1, CDR-L2, and CDR-H3, respectively, (g) SEQ ID NO: 99, 100, and 101 for CDR-H1, CDR-H2, and CDR-H3, respectively and SEQ ID NO: 103, 104, and 105 for CDR-L1, CDR-L2, and CDR-H3, respectively, (h) SEQ ID NO: 107, 108, and 109 for CDR-H1, CDR-H2, and CDR-H3, respectively and SEQ ID NO: 111, 112, and 113 for CDR-L1, CDR-L2, and CDR-H3, respectively, (i) SEQ ID NO: 115, 116, and 117 for CDR-H1, CDR-H2, and CDR-H3, respectively and SEQ ID NO: 119, 120, and 121 for CDR-L1, CDR-L2, and CDR-H3, respectively, (j) SEQ ID NO: 123, 124, and 125 for CDR-H1, CDR-H2, and CDR-H3, respectively and SEQ ID NO: 127, 128, and 129 for CDR-L1, CDR-L2, and CDR-H3, respectively, (k) SEQ ID NO: 131, 132, and 133 for CDR-H1, CDR-H2, and CDR-H3, respectively and SEQ ID NO: 135, 136, and 137 for CDR-L1, CDR-L2, and CDR-H3, respectively, (l) SEQ ID NO: 138, 139, and 140 for CDR-H1, CDR-H2, and CDR-H3, respectively and SEQ ID NO: 142, 143, and 144 for CDR-L1, CDR-L2, and CDR-H3, respectively, Or (m) CDR-H1, CDR-H2, CDR-H3, CDR-L1, CDR-L2, and CDR-L3 sequences which collectively differ by no more than three, no more than two, or one amino acid substitutions across all six CDRs from any of the foregoing sequences in (a)-(l).

[0021] In some embodiments, the HIV-1-binding antibody or HIV-1 binding fragment thereof comprises a heavy chain variable region comprising complementarity determining regions CDR-H1, CDR-H2, and CDR-H3, and a light chain variable region comprising complementarity determining regions CDR-L1, CDR-L2, and CDR-L3, having amino acid sequences of: (a) SEQ ID NO: 51, 52, and 53 for CDR-H1, CDR-H2, and CDR-H3, respectively and SEQ ID NO: 55, 56, and 57 for CDR-L1, CDR-L2, and CDR-H3, respectively, (b) SEQ ID NO: 59, 60, and 61 for CDR-H1, CDR-H2, and CDR-H3, respectively and SEQ ID NO: 63, 64, and 65 for CDR-L1, CDR-L2, and CDR-H3, respectively, (c) SEQ ID NO: 67, 68, and 69 for CDR-H1, CDR-H2, and CDR-H3, respectively and SEQ ID NO: 71, 72, and 73 for CDR-L1, CDR-L2, and CDR-H3, respectively, (d) SEQ ID NO: 75, 76, and 77 for CDR-H1, CDR-H2, and CDR-H3, respectively and SEQ ID NO: 79, 80, and 81 for CDR-L1, CDR-L2, and CDR-H3, respectively,(e) SEQ ID NO: 83, 84, and 85 for CDR-H1, CDR-H2, and CDR-H3, respectively and SEQ ID NO: 87, 88, and 89 for CDR-L1, CDR-L2, and CDR-H3, respectively, (f) SEQ ID NO: 91, 92, and 93 for CDR-H1, CDR-H2, and CDR-H3, respectively and SEQ ID NO: 95, 96, and 97 for CDR-L1, CDR-L2, and CDR-H3, respectively, (g) SEQ ID NO: 99, 100, and 101 for CDR-H1, CDR-H2, and CDR-H3, respectively and SEQ ID NO: 103, 104, and 105 for CDR-L1, CDR-L2, and CDR-H3, respectively, (h) SEQ ID NO: 107, 108, and 109 for CDR-H1, CDR-H2, and CDR-H3, respectively and SEQ ID NO: 111, 112, and 113 for CDR-L1, CDR-L2, and CDR-H3, respectively, (i) SEQ ID NO: 115, 116, and 117 for CDR-H1, CDR-H2, and CDR-H3, respectively and SEQ ID NO: 119, 120, and 121 for CDR-L1, CDR-L2, and CDR-H3, respectively, (j) SEQ ID NO: 123, 124, and 125 for CDR-H1, CDR-H2, and CDR-H3, respectively and SEQ ID NO: 127, 128, and 129 for CDR-L1, CDR-L2, and CDR-H3, respectively, (k) SEQ ID NO: 131, 132, and 133 for CDR-H1, CDR-H2, and CDR-H3, respectively and SEQ ID NO: 135, 136, and 137 for CDR-L1, CDR-L2, and CDR-H3, respectively, or (l) SEQ ID NO: 138, 139, and 140 for CDR-H1, CDR-H2, and CDR-H3, respectively and SEQ ID NO: 142, 143, and 144 for CDR-L1, CDR-L2, and CDR-H3, respectively.

[0022] In some embodiments, the HIV-1-binding antibody or HIV-1 binding fragment thereof comprises a heavy chain variable region and a light chain variable region, each having amino acid sequences that are at least 85%, at least 90%, at least 92.5%, at least 95%, at least 97.5%, at least 98%, at least 99%, or 100% identical to the sequences of (a) SEQ ID NO: 50 and SEQ ID NO: 54, respectively, (b) SEQ ID NO: 58 and SEQ ID NO: 62, respectively, (c) SEQ ID NO: 66 and SEQ ID NO: 70, respectively, (d) SEQ ID NO: 74 and SEQ ID NO: 78, respectively, (e) SEQ ID NO: 82 and SEQ ID NO: 86, respectively, (f) SEQ ID NO: 90 and SEQ ID NO: 94, respectively, (g) SEQ ID NO: 98 and SEQ ID NO: 102, respectively, (h) SEQ ID NO: 106 and SEQ ID NO: 110, respectively, (i) SEQ ID NO: 114 and SEQ ID NO: 118, respectively, (j) SEQ ID NO: 122 and SEQ ID NO: 126, respectively, (k) SEQ ID NO: 130 and SEQ ID NO: 134, respectively, or (l) SEQ ID NO: 138 and SEQ ID NO: 142, respectively.

[0023] In some embodiments, the nanocage monomer is a ferritin monomer or subunit thereof, e.g., a ferritin light chain or subunit thereof. In some embodiments, the ferritinmonomer or subunit thereof is a human ferritin or subunit thereof. In some embodiments, the ferritin monomer or subunit thereof is a ferritin monomer subunit.

[0024] In some embodiments, the HIV-1 antibody or an HIV-1-binding fragment thereof is a Fab fragment (e.g., a single chain Fab (scFab)) of an HIV-1 antibody.

[0025] In some embodiments, the HIV-1 binding antibody or HIV-1 binding fragment thereof is linked to the nanocage monomer via an amino acid linker, e.g., an amino acid linker comprising a (GnS)mlinker, e.g., a (GGGGS)mlinker.

[0026] In one aspect, provided are self-assembled polypeptide complexes comprising one or more fusion polypeptides, each fusion polypeptide being a fusion polypeptide as disclosed herein.

[0027] In one aspect, provided are self-assembled polypeptide complexes comprising (a) one or more first fusion polypeptides, each first fusion polypeptide comprising (1) a fragment of PDGM1400 linked to (2) a nanocage monomer or subunit thereof; (b) one or more second fusion polypeptides, each second fusion polypeptide comprising (1) a fragment of 10-1074 linked to (2) a nanocage monomer or subunit thereof; (c) one or more third fusion polypeptides, each third fusion polypeptide comprising (1) a fragment of N49P7 linked to (2) a nanocage monomer or subunit thereof; and (d) one or more fourth fusion polypeptides, each fourth fusion polypeptide comprising (1) an Fc polypeptide linked to (2) a nanocage monomer or subunit thereof.

[0028] In one aspect, provided are self-assembled polypeptide complexes comprising (a) one or more first fusion polypeptides, each first fusion polypeptide comprising (1) a fragment of PDGM1400 linked to (2) a nanocage monomer or subunit thereof; (b) one or more second fusion polypeptides, each second fusion polypeptide comprising (1) a fragment of ePGT121 linked to (2) a nanocage monomer or subunit thereof; (c) one or more third fusion polypeptides, each third fusion polypeptide comprising (1) a fragment of N49P9.6FR linked to (2) a nanocage monomer or subunit thereof; and (d) one or more fourth fusion polypeptides, each fourth fusion polypeptide comprising (1) an Fc polypeptide linked to (2) a nanocage monomer or subunit thereof.

[0029] In one aspect, provided are self-assembled polypeptide complexes comprising (a) one or more first fusion polypeptides, each first fusion polypeptide comprising (1) a fragment of PDGM1400 linked to (2) a nanocage monomer or subunit thereof; (b) one or more second fusion polypeptides, each second fusion polypeptide comprising (1) a fragment of ePGT121 linked to (2) a nanocage monomer or subunit thereof; (c) one or more third fusionpolypeptides, each third fusion polypeptide comprising (1) a fragment of N49P7 linked to (2) a nanocage monomer or subunit thereof; and (d) one or more fourth fusion polypeptides, each fourth fusion polypeptide comprising (1) an Fc polypeptide linked to (2) a nanocage monomer or subunit thereof.

[0030] In some embodiments, the nanocage monomer is a ferritin monomer or subunit thereof, e.g., a ferritin light chain or subunit thereof. In some embodiments, the ferritin monomer or subunit thereof is a human ferritin or subunit thereof. In some embodiments, the ferritin monomer or subunit thereof is a ferritin monomer subunit.

[0031] In some embodiments, the self-assembled polypeptide complex does not comprise any ferritin heavy chains or subunits of ferritin heavy chains.

[0032] In some embodiments, the HIV-1-binding moiety comprises an HIV-1 antibody or an HIV-1-binding fragment thereof, e.g., a Fab fragment (e.g., a single chain Fab (scFab)) of an HIV-1 antibody.

[0033] In some embodiments, the HIV-1 antibody is a broadly neutralizing antibody.

[0034] In one aspect, provided are pharmaceutical compositions comprising self-assembled polypeptide complexes as described herein and a pharmaceutically acceptable excipient.

[0035] In one aspect, provided are methods for treating and / or preventing HIV-1 infection and / or an HIV-1-associated condition, the method comprising administering a self-assembled polypeptide complex disclosed herein or a pharmaceutical composition disclosed herein, to a subject in need thereof.

[0036] In some embodiments, the subject is a mammal, e.g., a human.

[0037] In some embodiments, the administering comprises systemic administration, e.g., intranasal, intravascular, intramuscular, or subcutaneous administration.

[0038] In one aspect, provided are uses of the self-assembled polypeptide complexes described herein, or of pharmaceutical compositions disclosed herein, for treating and / or preventing HIV-1 infection and / or an HIV-1-associated condition.

[0039] In one aspect, provided are self-assembled polypeptide complexes and pharmaceutical compositions for use in treating and / or preventing HIV-1 infection and / or an HIV-1-associated condition. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] FIG.1A is a diagrammatic representation of human ferritin light chain (hFTL) and exemplary N-half ferritin and C-half ferritin molecules.

[0041] FIGs.1B, 1C, and 1D are diagrammatic representations of exemplary Multabodiesformats of the disclosure.

[0042] FIG.2A is a schematic of the human apoferritin split design that drives hetero- dimerization of scFab-human apoferritin subunits.

[0043] FIG.2B is a schematic representation of Multabody (MB) components.

[0044] FIG.2C is a schematic depicting the second-generation Multabody design (“MB.v2”), which displays two distinct features in comparison to the original Multabody design: 1) the Fc (green) is fused to the C terminus of the second half of apoferritin in the split ferritin design; and 2) the single-chain Fc domain (green), fused to the C terminus of an apoferritin half protomer is reverted to a monomeric Fc chain. Dimerization of each Fc in MB.v2 drives assembly of four Fabs (two Fab2 and two Fab3 – bottom row) while only one Fab is assembled per Fc into the previous MB version (top row).

[0045] FIGs.2D and 2E depict further features of Multabody v2. FIG.2D depicts modification of the fusion of the Fc (green) from the N terminus of N-ferritin (top row) to the C terminus of C-ferritin (bottom row) inverts the orientation of the Fc in the Multabody. FIG. 2E depicts Fc dimerization of two Fc chains fused to the C terminus of two independent ferritin subunits at the 4-fold symmetry axes of the apoferritin nanocage acting as an additional driver of Multabody v2 assembly.

[0046] FIG.3A depicts a schematic of the structure of the HIV-1 envelope protein (HIV- Env), indicating different epitopes on HIV-1 Env: CD4-binding site, V1 / V2 apex, V3 glycan, and gp120-gp41 interface, along with representative antibodies of each epitope class. Representative antibodies for the silent face are also listed.

[0047] FIGs.4A-4F depicts potency in HIV-1 pseudovirus (PsV) neutralization assays for various epitope classes. FIG.4A depicts fold changes in IC50 (as compared to a corresponding IgG molecule) from 12-mer or 24-mer V1 / V2 apex MBs against a PsV panel. FIG.4A depicts IC50 values (µg / mL) for ePDGDM1400 IgG, 12-mer MBs, or 24-mer MBs against various PsVs. FIG.4C depicts fold changes in IC50 (as compared to a corresponding IgG molecule) from 12-mer or 24-mer V3 glycan MBs against a PsV panel. FIG.4D depicts IC50values (µg / mL) for ePGT121 IgG or 12-mer MBs against various PsVs. FIG.4E depicts fold changes in IC50 (as compared to a corresponding IgG molecule) from 12-mer or 24-mer CD4 binding site (CD4bs) MBs against a PsV panel. Data represented is based on n = 2, except for the bar marked *, which was based on n = 1. FIG.4F depicts fold changes in IC50(as compared to a corresponding IgG molecule) from 12-mer gp120-gp41 interface MBs against a PsV panel.

[0048] FIG.4G is a schematic showing a general pattern of decreased potency boosts for monospecific MBs based on bnAbs targeting epitopes more proximal to the viral membrane.

[0049] FIG.5A shows the IC80 values (µg / mL) of various MBs (ER33, H03, H05, and H04) as compared to corresponding cocktails of IgGs.

[0050] FIG.5B shows the IC80 values (µg / mL) of various MBs (ER33, HIV03 (H03), HIV05 (H05), and HIV04 (H04) against a 119-pseudovirus panel. Results for HIV-1 IgGs or cocktails of IgGs (corresponding to the scFab components within each MB) are also shown for comparison.

[0051] FIG.5C shows the fraction of virus neutralized (within a 119 pseudovirus panel) plotted on the y-axis vs. the IC80cutoff in µg / mL on the x-axis for H04 MB, ER33 MB, H04 IgG mix, PGDM IgG, ePGT121 IgG, and N49P9.6FR IgG.

[0052] FIG.6 shows an assessment of binding of various IgGs and monospecific or trispecific MBs against cardiolipin, keyhole limpit haemocyanin (KLH), insulin, and dsDNA.

[0053] FIG.7A shows the IC80values (µg / mL) of various MBs (ER33, HIV03 (H03), HIV05 (H05), and HIV04 (H04) against a 24-pseudovirus panel. Results for HIV-1 IgGs or cocktails of IgGs (corresponding to the scFab components within each MB) are also shown for comparison. Results for HIV-1 IgGs or cocktails of IgGs (corresponding to the scFab components within H04 MB) are also shown for comparison.

[0054] FIG.7B is a plot showing the fraction of pseudovirus neutralized (x-axis) in a 24- pseudovirus panel according to varying IC50cutoffs in ^g / mL (y-axis) for H04 MB.

[0055] FIG.8 is a diagrammatic representation of an exemplary Multabody formats called “v1.2”. (See Example 5.)

[0056] FIG.9 shows the IC80 values (µg / mL) of H04 MBs having format “v2” or format “v1.2” against a 119-pseudovirus panel. DETAILED DESCRIPTION

[0057] The inventors have previously described the generation and characterization of HIV- 1 targeting self-assembled polypeptide complexes (“Multabodies”) which comprise (1) fusion polypeptides comprising an HIV-1-binding antibody fragment linked to a nanocage monomer or subunit thereof; and optionally (2) fusion polypeptides comprising an Fc polypeptide linked to a nanocage monomer or subunit thereof. Described herein are improved Multabodies which exhibit improved potency and / or broader neutralization than previously disclosed Multabodies.

[0058] In some embodiments, provided self-assembled polypeptide complexes comprise distinct antibody fragments having different specificities which collectively target more than one epitope of the HIV-1 envelope protein. For example, in some embodiments, provided are self-assembled polypeptide complexes which collectively target the CD4 binding site, the V1 / V2 interface, and the V3 glycan epitopes of HIV-1 Env.

[0059] In some embodiments, provided self-assembled polypeptide complexes achieve broad neutralization of pseudoviruses in a panel such as the reference HIV-1 pseudovirus panel described herein.

[0060] Also provided are fusion polypeptides which form part of such self-assembling polypeptide complexes, e.g., fusion polypeptides which comprise a nanocage monomer (e.g., ferritin polypeptide, e.g., ferritin light chain), as well as methods of making or methods of using provided self-assembled polypeptide complexes. Definitions

[0061] The terms “about” and “approximately,” when used herein in reference to a value, are used interchangeably and refer to a value that is similar to the referenced value. In general, those skilled in the art, familiar with the context, will appreciate the relevant degree of variation encompassed by “about” or “approximately” in that context. For example, in some embodiments, the terms “about” and “approximately” may encompass a range of values that fall within 25%, 20%, 19%, 18%, 17%, 16%, 15%, 14%, 13%, 12%, 11%, 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, or less of the referred value.

[0062] As used herein, the terms “alter,” “altered,” “decrease,” “decreased,” “increase,” “increased,” or “reduction,” “reduced,” (e.g., in reference to certain outcomes or effects) have meanings relative to a reference level. In some embodiments, in the context of discussing mutations in an Fc chain or Fc polypeptide, the reference level is a level known or as determined with an IgG that does not contain the referenced mutation(s) in the Fc region.

[0063] The terms “ferritin” and “apoferritin” are used interchangeably herein and generally refer to a polypeptide (e.g., a ferritin chain) that is capable of assembling into a ferritin complex which typically comprises 24 protein subunits. In some embodiments, the ferritin is a human ferritin, e.g., a human ferritin light chain, e.g., a human ferritin light chain having at least 85% sequence identity to SEQ ID NO:1 or UniProt P02792. In some embodiments, the ferritin is a wild-type ferritin. For example, the ferritin may be a wild-type human ferritin.

[0064] The term “ferritin monomer,” is used herein to refer to a single chain of a ferritin that, in the presence of other ferritin chains, is capable of self-assembling into a polypeptide complex comprising a plurality of ferritin chains, e.g., 24 or more ferritin chains.

[0065] As used herein, the term “linker” is used to refer to an entity that connects two or more elements to form a multi-element agent. For example, those of ordinary skill in the art appreciate that a polypeptide (e.g., fusion polypeptide) whose structure includes two or more functional or organizational domains often includes a stretch of amino acids between such domains that links them to one another. In some embodiments, a polypeptide comprising a linker element has an overall structure of the general form S1-L-S2, wherein S1 and S2 may be the same or different and represent two domains associated with one another by the linker (L). In some embodiments, the linker is an “amino acid linker,” that is, it comprises amino acid residues, e.g., an amino acid linker may comprise at least 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, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100 or more amino acid residues. In some embodiments, a linker is characterized in that it tends not to adopt a rigid three-dimensional structure, but rather provides flexibility to the polypeptide.

[0066] The term “multispecific,” as used herein, refers to the characteristic of having at least two binding sites at which at least two different binding partners, e.g., an antigen or receptor (e.g., Fc receptor), can bind. For example, a polypeptide complex that comprises at least two Fab fragments, wherein each of the two Fab fragments is capable of binding to a different antigen, is “multispecific.” As an additional example, a polypeptide complex that comprises an Fc fragment (which is capable of binding to an Fc receptor) and a Fab fragment (which is capable of binding to an antigen) is “multispecific.”

[0067] The term “multivalent,” as used herein, refers to the characteristic of having at least two binding sites at which a binding partner, e.g., an antigen or receptor (e.g., Fc receptor), can bind. The binding partners that can bind to the at least two binding sites may be the same or different.

[0068] The term “nanocage monomer,” as used herein, refers to a single chain of a polypeptide that is capable of self-assembling with other nanocage monomers to form a self- assembled polypeptide complex comprising a plurality of nanocage monomers. In some embodiments, the nanocage monomer is selected from monomers of ferritin, apoferritin, encapsulin, sulfur oxygenase reductase (SOR), lumazine synthase, pyruvate dehydrogenase, carboxysome, vault proteins, GroEL, heat shock protein, E2P coat protein, MS2 coat protein, fragments thereof, and variants thereof.

[0069] The term “polypeptide,” as used herein, generally has its art-recognized meaning of a polymer of at least three amino acids, e.g., linked to each other by peptide bonds. Those of ordinary skill in the art will appreciate that the term “polypeptide” is intended to be sufficiently general as to encompass not only polypeptides having a complete sequence recited herein, but also to encompass polypeptides that represent functional fragments (i.e., fragments retaining at least one activity) of such complete polypeptides. Moreover, those of ordinary skill in the art understand that protein sequences generally tolerate some substitution without destroying activity. Thus, any polypeptide that retains activity and shares at least about 30-40% overall sequence identity, often greater than about 50%, 60%, 70%, or 80%, and further usually including at least one region of much higher identity, often greater than 90% or even 95%, 96%, 97%, 98%, or 99% in one or more highly conserved regions, usually encompassing at least 3-4 and often up to 20 or more amino acids, with another polypeptide of the same class, is encompassed within the relevant term “polypeptide” as used herein. Polypeptides may contain L-amino acids, D-amino acids, or both and may contain any of a variety of amino acid modifications or analogs known in the art. Useful modifications include, e.g., terminal acetylation, amidation, methylation, etc. In some embodiments, proteins may comprise natural amino acids, non-natural amino acids, synthetic amino acids, and combinations thereof

[0070] As used herein, the terms “alter,” “altered,” “decrease,” “decreased,” “increase,” “increased,” or “reduction,” “reduced,” (e.g., in reference to certain outcomes or effects) have meanings relative to a reference level. In some embodiments, in the context of discussing mutations in an Fc chain or Fc polypeptide, the reference level is a level known or as determined with an IgG that does not contain the referenced mutation(s) in the Fc region.

[0071] The term “self-assembled,” when used in reference to a macromolecular complex (e.g., a polypeptide complex), refers to the spontaneous formation of that complex when sufficient constituents of the complex (e.g., fusion polypeptides) to be formed are present. In some embodiments, complexes self-assemble in physiological conditions, or in a buffer (e.g., a solution) that corresponds to physiological conditions.

[0072] As used herein, the term “subject” to an organism, typically a mammal (e.g., a human). In some embodiments, a subject is suffering from or susceptible to a relevant disease, disorder or condition. In some embodiments, a subject displays one or more symptoms or characteristics of a disease, disorder or condition. In some embodiments, a subject is someone with one or more features characteristic of susceptibility to or risk of a disease, disorder, or condition. In some embodiments, a subject is a patient. In someembodiments, a subject is a subject to whom diagnosis and / or therapy is and / or has been administered.

[0073] As used herein, the term “treatment” (also “treat” or “treating”) refers to any administration of a therapy that partially or completely alleviates, ameliorates, relieves, inhibits, delays onset of, reduces severity of, and / or reduces incidence of one or more symptoms, features, and / or causes of a particular disease, disorder, and / or condition. In some embodiments, such treatment may be of a subject who does not exhibit signs of the relevant disease, disorder and / or condition and / or of a subject who exhibits only early signs of the disease, disorder, and / or condition. Alternatively, or additionally, such treatment may be of a subject who exhibits one or more established signs of the relevant disease, disorder and / or condition. In some embodiments, treatment may be of a subject who has been diagnosed as suffering from the relevant disease, disorder, and / or condition. In some embodiments, treatment may be of a subject known to have one or more susceptibility factors that are statistically correlated with increased risk of development of the relevant disease, disorder, and / or condition.

[0074] As used herein, the term “variant,” when used in reference to a polypeptide, polynucleotide, or subsequence or fragment thereof, refers to a polypeptide, polynucleotide, subsequence, or fragment thereof which is similar in sequence (e.g., amino acid sequence or nucleotide sequence) to the reference polypeptide, polynucleotide, or subsequence or fragment thereof, except for some amino acid residues or nucleotides which differ from the reference polypeptide, polynucleotide, or subsequence or fragment thereof. For example, in some embodiments, a variant of a reference complementarity-determining region (CDR) of an immunoglobulin variable domain may be identical to a reference CDR sequence except for one, two, or three amino acid differences (e.g., insertions, deletions, or substitutions). For example in some embodiments, a variant of a reference variable region of immunoglobulin chain may have at least 85%, at least 87.5%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identity (but less than 100%) amino acid sequence identity with the reference variable region. A. Fusion polypeptides

[0075] In many embodiments, fusion polypeptides compatible with compositions and methods disclosed herein generally comprise a nanocage monomer or subunit thereof linked to either an Fc polypeptide or to an HIV-1 binding moiety. Within the fusion polypeptide, theFc polypeptide or HIV-1 binding moiety may be linked to the nanocage monomer or subunit thereof at a particular terminus of the nanocage monomer or subunit thereof, e.g., the N- terminus or the C-terminus. In some embodiments, the Fc polypeptide or HIV-1 binding moiety is linked via an amino acid linker, such as a linker as described herein. 1. Nanocage monomers and subunits thereof

[0076] In some embodiments, the nanocage monomer is a ferritin monomer.

[0077] The term “ferritin monomer,” is used herein to refer to a single chain of a ferritin that, in the presence of other ferritin chains, is capable of self-assembling into a polypeptide complex comprising a plurality of ferritin chains, e.g., 24 or more ferritin chains. In some embodiments, the ferritin monomer is a ferritin light chain. In some embodiments, the ferritin monomer does not include a ferritin heavy chain or other ferritin components capable of binding to iron.

[0078] In some embodiments, each fusion polypeptide within the self-assembled polypeptide complex comprises a ferritin light chain or a subunit of a ferritin light chain. In these embodiments, the self-assembled polypeptide complex does not comprise any ferritin heavy chains or subunits of ferritin heavy chains.

[0079] In some embodiments, the ferritin monomer is a human ferritin chain, e.g., a human ferritin light chain, e.g., a human ferritin light chain having the sequence of at least residues 2-175 of SEQ ID NO:1. In some embodiments, the ferritin monomer is a mouse ferritin chain.

[0080] A “subunit” of a ferritin monomer refers to a portion of a ferritin monomer that is capable of spontaneously associating with another, distinct subunit of a ferritin monomer, so that the subunits together form a ferritin monomer, which ferritin monomer, in turn, is capable of self-assembling with other ferritin monomers to form a polypeptide complex.

[0081] In some embodiments, the ferritin monomer subunit comprises approximately half of a ferritin monomer. As used herein, the term “N-half ferritin” refers to approximately half of a ferritin chain, which half comprises the N-terminus of the ferritin chain. As used herein, the term “C-half ferritin” refers to approximately half a ferritin chain, which half comprises the C-terminus of the ferritin chain. The exact point at which a ferritin chain may be divided to form the N-half ferritin and the C-half ferritin may vary depending on the embodiment. In the context of ferritin monomer subunits based on human ferritin light chain, for example, the halves may be divided at a point that corresponds to a position from about position 75 to about position 100 of SEQ ID NO:1 (or a substantial portion thereof). For example, in someembodiments, an N-half ferritin based on a human ferritin light chain has an amino acid sequence corresponding to residues 1-95 of SEQ ID NO: 1 (or a substantial portion thereof), and a C-half ferritin based on a human ferritin light chain has an amino acid sequence corresponding to residues 96-175 of SEQ ID NO: 1 (or a substantial portion thereof).

[0082] In some embodiments, the halves are divided at a point that corresponds to a position from about position 85 to about position 92 of SEQ ID NO:1. For example, in some embodiments, an N-half ferritin based on a human ferritin light chain has an amino acid sequence corresponding to residues 1-90 of SEQ ID NO:1, and a C-half ferritin based on a human ferritin light chain has an amino acid sequence corresponding to residues 91-175 of SEQ ID NO:1. 2. HIV-1 binding moiety

[0083] An “HIV-1 binding moiety” as used herein is a moiety that is capable of binding to an epitope on HIV-1. In some embodiments, the HIV-1 binding moiety is capable of binding to an epitope on the HIV-1 envelope protein (HIV-1 Env), for example, an epitope selected from the group consisting of the V1 / V2 apex, the V3 glycan, the CD4 binding site (“CD4bs”), the gp120-gp41 interface, or the silent interface.

[0084] In certain embodiments, the HIV-1 binding moiety comprises an HIV-1 antibody (an antibody capable of binding to an epitope on HIV-1) or HIV-1 binding fragment thereof (a fragment capable of binding to an epitope on HIV-1, interchangeably referred to as “HIV-1 antibody fragment”), such as a broadly neutralizing HIV-1 antibody (HIV-1 bnAb) or fragment thereof.

[0085] Examples of HIV-1 bnAbs which can be used, or whose antibody fragments can be used, in accordance with the present disclosure include, for example, those HIV-1 bnAbs whose heavy and light chain variable region sequences and complementarity-determining region (CDR) sequences (according to Kabat) are shown in Table 1. Table 1 includes examples of bnAbs that are capable of binding to the V1 / V2 apex, to the V3 glycan, to the CD4 binding site, to the gp120-gp41 interface, or to the silent face of HIV-1 Env. Table 1. Exemplary HIV-1 bnAbs and their heavy chain variable domain, light chain variable domain, and complementary-determining region sequences (according to Kabat) HIV-1 Heavy chain variable domain Light chain variable domain (VL) antibody (VH) V1 / V2 apex epitope classPGDM1400QAQLVQSGPEVRKPGTSVKVSCKADFVLTQSPHSLPVTPGESASISCK PGNTLKTYDLHWVRSVPGQGLQWM SSHSLIHGDRNNYLAWYVQKPGRS GWISHEGDKKVIVERFKAKVTIDW PQLLIYLASSRASGVPDRFSGSGS DRSTNTAYLQLSGLTSGDTAVYYC DKDFTLKISRVETEDVGTYYCMQG AKGSKHRLRDYALYDDDGALNWAV RESPWTFGQGTKVDIK (SEQ ID DVDYLSNLEFWGQGTAVTVSS NO: 54) (SEQ ID NO: 50) CDR-H1: KAPGNTLKTYDLH (SEQ CDR-L1:KSSHSLIHGDRNNYLA ID NO: 51) (SEQ ID NO: 55) CDR-H2: WISHEGDKKV (SEQ ID CDR-L2:YLASSRAS (SEQ ID NO: NO: 52) 56) CDR-H3: CDR-L3:MQGRESPWT (SEQ ID AKGSKHRLRDYALYDDDGALNWAV NO: 57) DVDYLSNLEF (SEQ ID NO: 53) ePGDM1400v9 QAQLVQSGPEVRKPGTSVKVSCKN DIVLTQSPLSLSVTPGESASISCK (obtained with PGNTLTTYDLHWVRQVPGQGLQWM SSQSLIHGDRNNYLAWYVQKPGRS permission GWISHEGDKKVIVERFKAKVTIDW PQLLIDLASERASGVPDRFSGSGS from the DRSTNTAYLQLSGLTSEDTAVYYC RKDFTLKISRVETEDVGTYYCMQG Scripps AKGSKHRLRDYALYDEDGALNWAV RESPWTFGQGTKVDIK (SEQ ID Research DVDYLANLEFWGQGTAVTVSS NO: 62) Institute and the (SEQ ID NO: 58) International AIDS Vaccine CDR-H1: KNPGNTLTTYDLH (SEQ CDR-L1:KSSQSLIHGDRNNYLA Initiative ID NO: 59) (SEQ ID NO: 63) (IAVI)) CDR-H2: WISHEGDKKV (SEQ ID CDR-L2:DLASERAS (SEQ ID NO: NO: 60) 64) CDR-H3: CDR-L3:MQGRESPWT (SEQ ID AKGSKHRLRDYALYDEDGALNWAV NO: 65) DVDYLANLEF (SEQ ID NO: 61)PG9QRLVESGGGVVQPGSSLRLSCAAS QSALTQPASVSGSPGQSITISCNG GFDFSRQGMHWVRQAPGQGLEWVA TSNDVGGYESVSWYQQHPGKAPKV FIKYDGSEKYHADSVWGRLSISRD VIYDVSKRPSGVSNRFSGSKSGNT NSKDTLYLQMNSLRVEDTATYFCV ASLTISGLQAEDEGDYYCKSLTST REAGGPDYRNGYNYYDFYDGYYNY RRRVFGTGTKLTVL (SEQ ID NO: HYMDVWGKGTTVTVSS (SEQ ID 70) NO: 66) CDR-H1: AASGFDFSRQGMH (SEQ CDR-L1:NGTSNDVGGYESVS ID NO: 67) (SEQ ID NO: 71) CDR-H2: FIKYDGSEKY (SEQ ID CDR-L2:YDVSKRPS (SEQ ID NO: NO: 68) 72) CDR-H3: CDR-L3:KSLTSTRRRV (SEQ ID VREAGGPDYRNGYNYYDFYDGYYN NO: 73) YHYMDV (SEQ ID NO: 69)PG16QEQLVESGGGVVQPGGSLRLSCLA QSALTQPASVSGSPGQTITISCNG SGFTFHKYGMHWVRQAPGKGLEWV TSSDVGGFDSVSWYQQSPGKAPKV ALISDDGMRKYHSDSMWGRVTISR MVFDVSHRPSGISNRFSGSKSGNT DNSKNTLYLQFSSLKVEDTAMFFC ASLTISGLHIEDEGDYFCSSLTDR AREAGGPIWHDDVKYYDFNDGYYN SHRIFGGGTKVTVL (SEQ ID NO: YHYMDVWGKGTTVTVSS (SEQ ID 78) NO: 74) CDR-H1: LASGFTFHKYGM (SEQ CDR-L1:NGTSSDVGGFDSVS ID NO: 75) (SEQ ID NO: 79) CDR-H2: LISDDGMRKY (SEQ ID CDR-L2:FDVSHRPS (SEQ ID NO: NO: 76) 80) CDR-H3: CDR-L3:SSLTDRSHRI (SEQ ID EAGGPIWHDDVKYYDFNDGYYNYH NO: 81) YMDV (SEQ ID NO: 77) V3 glycan epitope classePGT121 QMQLQESGPGLVKPGETLSLTCSV SDISVAPGETVRISCGGESIGSRA (obtained with SGASISSSYWSWLRETPGKGLEWI VQWYQHRAGQAPKLIIYNNQDRPP permission GYTHHSGDTNYAPSLKSRVHLGLH GIPERFSGSPDIDFGTTATLTITN from the PSKNQVSLSLTSVTAADTAVYYCA VEAGDEATYYCHIWDSRRPTNWVF Scripps RTLHGRRIYGVVAFNEFFTYFYWE GGGTTLTVL (SEQ ID NO: 86) Research VWGKGTQVTVSS (SEQ ID NO: Institute and 82) IAVI) CDR-H1: SVSGASISSSYWS (SEQ CDR-L1:GGESIGSRAVQ (SEQ ID ID NO: 83) NO: 87) CDR-H2: YTHHSGDTN (SEQ ID CDR-L2:YNNQDRPP (SEQ ID NO: NO: 84) 88) CDR-H3: CDR-L3:HIWDSRRPTNWV (SEQ ARTLHGRRIYGVVAFNEFFTYFYW ID NO: 89) EV (SEQ ID NO: 85) 10-1074QVQLQESGPGLVKPSETLSVTCSV SYVRPLSVALGETARISCGRQALG SGDSMNNYYWTWIRQSPGKGLEWI SRAVQWYQHRPGQAPILLIYNNQD GYISDRESATYNPSLNSRVVISRD RPSGIPERFSGTPDINFGTRATLT TSKNQLSLKLNSVTPADTAVYYCA ISGVEAGDEADYYCHMWDSRSGFS TARRGQRIYGVVSFGEFFYYYSMD WSFGGATRLTVL (SEQ ID NO: 94) VWGKGTTVTVSS (SEQ ID NO: 90) CDR-H1: SVSGDSMNNYYWT (SEQ CDR-L1:GRQALGSRAVQ (SEQ ID ID NO: 91) NO: 95) CDR-H2: YISDRESAT (SEQ ID CDR-L2:YNNQDRPS (SEQ ID NO: NO: 92) 96) CDR-H3: CDR-L3:HMWDSRSGFSWS (SEQ ATARRGQRIYGVVSFGEFFYYYSM ID NO: 97) DV (SEQ ID NO: 93)AIIMSP01QVQLQESGPGLVKPSETLSLTCTVQSVLTQPPSASGTPGQRVTISCSG SGGSMNSDYWSWIRQPPGKGLEWI GSPNIGSNWVYWYQHVPGTAPKLL GYIYYTGNTDSNPSRYNPSLKSRV IYTNDQRPSGVPDRFSGSKSGTTA TISIDSSKNQFSLKLRSVTAADTA SLAISGLRSEDEAHYYCAAWDDTL IYYCARDKVVPARWSGYYYYGMNI SSLLFGGGTKLTVL (SEQ ID NO: WGQGTTVTVSS (SEQ ID NO: 98) 102) CDR-H1: TVSGGSMNSDYWS (SEQ CDR-L1:SGGSPNIGSNWVY (SEQ ID NO: 99) ID NO: 103) CDR-H2: YIYYTGNTDSNPSR CDR-L2:YTNDQRPS (SEQ ID NO: (SEQ ID NO: 100) 104) CDR-H3: CDR-L3:AAWDDTLSSLL (SEQ ID ARDKVVPARWSGYYYYGMNI (SEQ NO: 105) ID NO: 101) CD4 binding site epitope class N49P7 ADLVQSGAVVKKPGDSVRISCEAQ QSALTQPRSVSASPGQSVTISCTG (obtained with GYRFPDYIIHWIRRAPGQGPEWMG THNLVSWCQHQPGRAPKLLIYDFN permission WMNPMGGQVNIPWKFQGRVSMTRD KRPSGVPDRFSGSGSGGTASLTIT from the TSIETAFLDLRGLKSDDTAVYYCV GLQDDDDAEYFCWAYEAFGGGTKL University of RDRSNGSGKRFESSNWFLDLWGRG TVL (SEQ ID NO: 110) Maryland) TAVTI (SEQ ID NO: 106) CDR-H1: EAQGYRFPDYIIH (SEQ CDR-L1:TGTHNLVS (SEQ ID NO: ID NO: 107) 111) CDR-H2: WMNPMGGQVN (SEQ ID CDR-L2:YDFNKRPS (SEQ ID NO: NO: 108) 112) CDR-H3: CDR-L3:WAYEA (SEQ ID NO: VRDRSNGSGKRFESSNWFLDL 113) (SEQ ID NO: 109)N49P9.6-FRHVQLVQSGGGVKKIGAAVRISCEV ASALTQPASMSASPGQSVTISCSG SGYNFMDQFINWVRQAPGQGLEWM TRHIISAWFQQYPGKPPKLIIFDD(obtained with GWMNPIYGQVNYSWRFQGRVTMTR DKRPSGVPSRFSASRPGDTASLTI permission QLSQDPDDPDWGTAFMELRGLRVD SNVQPEDEATYICNTYEFFGGGTK from the DTAVYYCARGPSGENYPFHYWGQG LTVL (SEQ ID NO: 118) University of VRVVVSS (SEQ ID NO: 114) CDR-L1:SGTRHIISA (SEQ ID Maryland) NO: 119) CDR-H1: EVSGYNFMDQFIN (SEQ CDR-L2:FDDDKRPS (SEQ ID NO: ID NO: 115) 120) CDR-H2: WMNPIYGQVN (SEQ ID CDR-L3:NTYEF (SEQ ID NO: NO: 116) 121) CDR-H3: ARGPSGENYPFHY (SEQ ID NO: 117) gp120-gp41 interface PGT151QLVESGGGVVQPGKSVRLSCVVSD DIVMTQTPLSLPVTPGQPASISCK FPFSKYPMYWVRQAPGKGLEWVAA SSESLRQSNGKTSLYWYRQKPGQS ISGDAWHVVYSNSVQGRFLVSRDN PQLLVFEVSNRFSGVSDRFVGSGS VKNTLYLEMNSLKIEDTAVYRCAR GTDFTLRISRVEAEDVGFYYCMQS MFQESGPPRLDRWSGRNYYYYSGM KDFPLTFGGGTKVDLK (SEQ ID DVWGQGTTVTVSS (SEQ ID NO: NO: 126) 122) CDR-H1: KYPMY (SEQ ID NO: CDR-L1:KSSESLRQSNGKTSLY 123) (SEQ ID NO: 127) CDR-H2: AISGDAWHVVYSNSVQG CDR-L2:EVSNRFS (SEQ ID NO: (SEQ ID NO: 124) 128) CDR-H3: CDR-L3:MQSKDFPLT (SEQ ID ARMFQESGPPRLDRWSGRNYYYYS NO: 129) GMDV (SEQ ID NO: 125) Silent interface SF5QVQLQESGPGLVKPSETLSVTCRV QIVLTQSPRTLSLSAGERATLLCR SGGSLDRYYWSWIRQPPGEGLQWI ASQSVSNVALAWYQHKPGQAPRLL GHVYFDGSYGDYDPSLRSRVTITA LHEASIRAAGIPDRFVGSGSGRDFDMSKYQIILRLRSVTPADTAVYYC TLTITSLHPEDFAVYYCQLSGRRL ARLGPGGIFDRWTGHYGDKWLDPW GPGTKVEIK (SEQ ID NO: 134) GQGTLVTVSS (SEQ ID NO: 130) CDR-H1: LDRYYWS (SEQ ID NO: CDR-L1:RASQSVSNVALA (SEQ 131) ID NO: 135) CDR-H2: HVYFDGSYGDYDPSLRS CDR-L2:EASIRAA (SEQ ID NO: (SEQ ID NO: 132) 136) CDR-H3: CDR-L3:QLSGRR (SEQ ID NO: ARLGPGGIFDRWTGHYGDKWLDP 137) (SEQ ID NO: 133) SF12QVQLQESGPGLVKPSETLSVTCRV QIDLTQSPRTLSLSAGERATLLCR SGGSLDLYYWSWIRQPPGKGLQWI ASQSVSNVALAWYQHKPGQAPRLL GFVYFDGSYGDYDPSLRSRVTISA LHEASTRATGIPDRFIGSGSGRDF DMSKNQISLRLKSVTPADTAVYYC TLTITSLEPEDFAVYYCQLSGRRL ARLGPGGIFDRWTGHYGDKWLDPW GQGTKVEIK (SEQ ID NO: 142) GQGTLVTVSS (SEQ ID NO: 138) CDR-H1: LYYWS (SEQ ID NO: CDR-L1:RASQSVSNVALA (SEQ 139) ID NO: 143) CDR-H2: FVYFDGSYGDYDPSLRS CDR-L2:EASTRAT (SEQ ID (SEQ ID NO: 140) NO:144) CDR-H3: CDR-L3:QLSGRR (SEQ ID NO: ARLGPGGIFDRWTGHYGDKWLDP 145) (SEQ ID NO: 141)

[0086] In some embodiments, the HIV-1 binding moiety comprises an immunoglobulin heavy chain variable domain, wherein the immunoglobulin heavy chain variable domain comprises a CDR-H3 (or a variant thereof) of an antibody described in Table 1. In some embodiments, the HIV-1 binding moiety also comprises an immunoglobulin light chain variable domain. In some embodiments, the HIV-1 binding moiety’s immunoglobulin heavychain variable domain comprises a CDR-H3 (or a variant thereof) of an antibody described in Table 1, and the HIV-1 binding moiety’s immunoglobulin light chain variable domain comprises a CDR-L3 (or a variant thereof) of the same antibody described in Table 1.

[0087] In some embodiments, the HIV-1 binding moiety comprises an immunoglobulin heavy chain variable domain and an immunoglobulin light chain variable domain, wherein the immunoglobulin heavy chain variable domain comprises a CDR-H1, CDR-H2, and CDR- H3, and the immunoglobulin light chain variable domain comprises a CDR-L1, CDR-L2, and CDR-L3, wherein the CDR-H1, CDR-H2, CDR-H3, CDR-L1, CDR-L2, and CDR-L3, are those of an antibody described in Table 1. In some embodiments, the HIV-1 binding moiety is a variant of an antibody described in Table 1 or is an HIV-1 binding fragment thereof, in that the HIV-1 binding moiety comprises immunoglobulin heavy and light chain variable regions which have CDR sequences that differ by no more than two amino acid residues (e.g., two or one amino acid residue(s)) per CDR from the CDR sequences of an antibody described in Table 1. In some embodiments, the HIV-1 binding moiety is a variant of an antibody described in Table 1 or is an HIV-1 binding fragment thereof, in that the HIV-1 binding moiety comprises immunoglobulin heavy and light chain variable regions which together have a set of six CDRs whose sequences collectively differ by no more than two amino acid residues (e.g., two or one amino acid residues) from the CDRs of an antibody described in Table 1.

[0088] In some embodiments, the HIV-1 binding moiety comprise an immunoglobulin heavy chain variable domain and an immunoglobulin light chain variable domain which comprises immunoglobulin heavy chain variable domain and immunoglobulin light chain variable sequences of an antibody described in Table 1. In some embodiments, the HIV-1 binding moiety is a variant of an antibody described in Table 1 or is an HIV-1 binding fragment thereof, in that the HIV-1 binding moiety has (1) an immunoglobulin heavy chain domain comprising an amino acid sequence that is at least 85%, at least 87.5%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to the amino acid sequence of the immunoglobulin heavy chain variable domain of an antibody described in Table 1; and (2) an immunoglobulin light chain domain comprising an amino acid sequence that is at least 85%, at least 87.5%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to the amino acid sequence of an immunoglobulin light chain variable domain of the same antibody described in Table 1.

[0089] In some embodiments, the HIV-1 binding moiety is an antibody fragment, e.g., a Fab. In some embodiments, the antibody fragment is a single-chain Fab (scFab); for example, a fusion polypeptide comprising both the heavy and light chains of a Fab, optionally linked by a linker (e.g., amino acid linker as disclosed herein) is used.

[0090] In certain embodiments, the HIV-1 antibody or HIV-1 binding antibody fragment comprises a heavy chain variable region (e.g., a VH). In certain embodiments, the HIV-1 antibody or HIV-1 binding antibody fragment comprises a heavy chain variable domain (e.g., VH) and a light chain variable domain (e.g., a VL or VK). In certain embodiments, the HIV-1 antibody or HIV-1 binding antibody fragment comprises a Fab which comprises a heavy chain variable domain (e.g., VH) and a light chain variable domain (e.g., a VLor VK).

[0091] In certain embodiments, the HIV-1 antibody or HIV-1 binding antibody fragment does not comprise any domains from the Fc region, e.g., does not comprise any CH2 or CH3 domains.

[0092] In embodiments where multiple types of fusion polypeptides having HIV-1 antibodies or HIV-1-binding antibody fragments are used, each HIV-1 antibody or HIV-1 binding antibody fragment may be capable of binding to the same epitope, or they may be capable of binding to epitopes that are distinct and non-overlapping. In some embodiments in which the epitopes are distinct and non-overlapping, the epitopes are from the same protein. 3. Fc polypeptides

[0093] As used herein, the term “Fc polypeptide” refers to a polypeptide comprising at least one immunoglobulin Fc chain (e.g., IgG Fc chain). In some embodiments, an Fc polypeptide comprises two Fc chains, e.g., Fc chains linked together.

[0094] In some embodiments, the Fc polypeptide comprises a single chain Fc (scFc), which comprises two Fc chains linked together by a covalent linker, e.g., via an amino acid linker.

[0095] An IgG Fc chain (e.g., IgG1 Fc chain) typically contains two constant heavy domains (CH2 and CH3) and a hinge region connected to the CH2 domain.

[0096] In certain embodiments, fragment crystallizable (Fc) polypeptides comprise Fc chains that each have one or more mutations relative to a reference Fc chain of the same Ig class. As explained further herein below, the reference Fc chain may be of, e.g., the IgG1, IgG2 class, or IgG4 class.

[0097] Unless otherwise noted, numbering of mutations within an antibody fragment, e.g., an Fc polypeptide, throughout this disclosure is according to the EU index.

[0098] In some embodiments, the Fc polypeptide is a human IgG Fc polypeptide, that is, except for mutations noted herein, the Fc polypeptide comprises an Fc chain that is substantially similar to that of an Fc chain within a wild type human IgG.

[0099] In some embodiments, the Fc polypeptide is an IgG1 Fc polypeptide (e.g., a human IgG1 Fc polypeptide), that is, except for mutations noted herein, the Fc polypeptide comprises an Fc chain that has an amino acid sequence that is substantially similar to that of the chains within a wild type IgG1 Fc. In some embodiments, the wild type IgG1 Fc is a human IgG1 Fc, in which each Fc chain has an amino acid sequence of SEQ ID NO:5.

[0100] For example, an IgG1 Fc polypeptide may comprise an Fc chain with an amino acid sequence that is at least 85%, at least 87.5%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to that of an Fc chain within a wild-type IgG1 Fc. In some embodiments, an IgG1 Fc polypeptide comprises an Fc chain that comprises the Fc mutations specifically described for that IgG1 Fc polypeptide, but has an amino acid sequence that is otherwise 100% identical to an Fc chain within a wild type IgG1 Fc. In some embodiments, the Fc polypeptide comprises an Fc chain that has an amino acid sequence that differs by at least one, at least two, at least three, or at least four amino acid residues from the sequence of SEQ ID NO:5. In some embodiments, the Fc polypeptide comprises an Fc chain that has an amino acid sequence that differs by no more than ten, no more than nine, no more than eight, no more than seven, no more than six, no more than five, or no more than four amino acid residues from the sequence of SEQ ID NO:5.

[0101] In some embodiments, the Fc polypeptide is an IgG2 Fc polypeptide, (e.g., a human IgG2 Fc polypeptide), that is, except for mutations noted herein, the Fc polypeptide comprises an Fc chain that has an amino acid sequence that is substantially similar to that of the chains within a wild type IgG2 Fc. In some embodiments, the wild type IgG2 Fc is a human IgG2 Fc, in which each Fc chain has an amino acid sequence of SEQ ID NO:46.

[0102] For example, an IgG2 Fc polypeptide may comprise an Fc chain with an amino acid sequence that is at least 85%, at least 87.5%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to that of an Fc chain within a wild-type IgG2 Fc. In some embodiments, an IgG2 Fc polypeptide comprises an Fc chain that comprises the Fc mutations specifically described for that IgG2 Fc polypeptide, but has an amino acid sequence that is otherwise 100% identical to an Fc chain within a wild type IgG2 Fc. In some embodiments, the Fc polypeptide comprises an Fc chain that has an amino acid sequence that differs by at leastone, at least two, at least three, or at least four amino acid residues from the sequence of SEQ ID NO:46. In some embodiments, the Fc polypeptide comprises an Fc chain that has an amino acid sequences that differs by no more than ten, no more than nine, no more than eight, no more than seven, no more than six, no more than five, or no more than four amino acid residues from the sequence of SEQ ID NO:46.

[0103] In some embodiments, the Fc polypeptide is an IgG4 Fc polypeptide, (e.g., a human IgG2 Fc polypeptide), that is, except for mutations noted herein, the Fc polypeptide comprises an Fc chain that has an amino acid sequence that is substantially similar to that of the chains within a wild type IgG4 Fc. In some embodiments, the wild type IgG4 Fc is a human IgG4 Fc, in which each Fc chain has an amino acid sequence of SEQ ID NO:9.

[0104] For example, an IgG4 Fc polypeptide may comprise an Fc chain with an amino acid sequence that is at least 85%, at least 87.5%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to that of an Fc chain within a wild-type IgG4 Fc. In some embodiments, an IgG4 Fc polypeptide comprises an Fc chain that comprises the Fc mutations specifically described for that IgG4 Fc polypeptide, but has an amino acid sequence that is otherwise 100% identical to an Fc chain within a wild type IgG4 Fc. In some embodiments, the Fc polypeptide comprises an Fc chain that has an amino acid sequence that differs by at least one, at least two, at least three, or at least four amino acid residues from the sequence of SEQ ID NO:9. In some embodiments, the Fc polypeptide comprises an Fc chain that has an amino acid sequences that differs by no more than ten, no more than nine, no more than eight, no more than seven, no more than six, no more than five, or no more than four amino acid residues from the sequence of SEQ ID NO:9.

[0105] In some embodiments, the Fc polypeptide is a single chain Fc (scFc), which comprises two Fc chains linked together by a covalent linker, e.g., via an amino acid linker.

[0106] In some embodiments, the Fc polypeptide is an Fc monomer, e.g., a single Fc chain having only one CH2 domain (second constant Ig domain of the heavy chain) and only one CH3 domain (third constant Ig domain of the heavy chain), which single Fc chain is typically capable of dimerizing with another single Fc chain.

[0107] In some embodiments, the one or more mutations comprises a mutation or set of mutations associated with an altered characteristic as further described herein. By “associated with,” it is meant that the mutation or set of mutations has been previously characterized, in the context of antibodies such as IgG antibodies, as conferring the altered characteristic (e.g., altered binding to FcRn, altered effector function, etc.) By “altered” it is meant that thecharacteristic (e.g., binding to an Fc receptor (e.g., FcRn)), is different than that observed without the mutation or set of mutations.

[0108] For example, in some embodiments, the altered characteristic comprises altered binding to an Fc receptor.

[0109] In some embodiments, the altered characteristic comprising altered binding to FcRn.

[0110] For example, the mutation or set of mutations associated with altered binding to FcRn may comprise a mutation at one or more residues selected from: M428, N434, or combinations thereof, e.g., the M428L / N434S (“LS”) mutation. 4. Linkers

[0111] In certain embodiments, linkers are used within fusion polypeptides and / or within single-chain molecules such as scFcs. In some embodiments, the linker is an amino acid linker. For example, a linker as employed herein may comprise from about 1 to about 100 amino acid residues, e.g., about 1 to about 70, about 2 to about 70, about 1 to about 30, or about 2 to about 30 amino acid residues. In some embodiments, the linker comprises at least 2, at least 3, at least 4, at least 5, at least 6, at least 7, at least 8, at least 9, or at least 10 amino acid residues.

[0112] In certain embodiments, the linker comprises a glycine-serine sequence, e.g., a (GnS)msequence (e.g., GGS, GGGS (SEQ ID NO:48), or GGGGS (SEQ ID NO:49) sequence) that is present in at least 1, at least 2, at least 3, at least 4, at least 5, at least 6, at least 7, at least 8, at least 9, at least 10, at least 11, at least 12, at least 13, or at least 14 copies within the linker. B. Self-assembled polypeptide complexes

[0113] In one aspect, provided are self-assembled polypeptide complexes comprising one or more fusion polypeptides as disclosed herein. Generally, provided self-assembled polypeptide complexes comprise (a) one or more first fusion polypeptides (“HIV-1 binding fusion polypeptides”), each first fusion polypeptide comprising (1) an HIV-1 binding moiety linked to (2) a nanocage monomer or subunit thereof and (b) one or more second fusion polypeptides, each second fusion polypeptide comprising (1) an Fc polypeptide linked to (2) a nanocage monomer or subunit thereof.

[0114] In some embodiments, the nanocage monomer is a ferritin monomer, and each fusion polypeptide within the self-assembled polypeptide complex comprises a ferritin light chain or a subunit of a ferritin light chain. In these embodiments, the self-assembledpolypeptide complex does not comprise any ferritin heavy chains, subunits of ferritin heavy chains, or other ferritin components capable of binding to iron.

[0115] In some embodiments, the nanocage monomer or subunit thereof is a ferritin monomer subunit, and (a) each first fusion polypeptide comprises a ferritin monomer subunit which is C-half-ferritin and each second fusion polypeptide comprises a ferritin monomer subunit which is N-half-ferritin; or (b) each first fusion polypeptide comprises a ferritin monomer subunit which is N-half ferritin and each second fusion polypeptide comprises a ferritin monomer subunit which is C-half-ferritin.

[0116] In some embodiments, the self-assembled polypeptide complex comprises from 24 to 48 fusion polypeptides in total. In some embodiments, the self-assembled polypeptide complex comprises 24 fusion polypeptides in total. In some embodiments, the self-assembled polypeptide complex comprises more than 24 fusion polypeptides, e.g., at least 26, at least 28, at least 30, at least 32 fusion polypeptides, at least 34 fusion polypeptides, at least 36 fusion polypeptides, at least 38 fusion polypeptides, at least 40 fusion polypeptides, at least 42 fusion polypeptides, at least 44 fusion polypeptides, at least 46 fusion polypeptides, or at least 48 fusion polypeptides in total. In some embodiments, the self-assembled polypeptide complex comprises about 32 fusion polypeptides.

[0117] In some embodiments, the self-assembled polypeptide complex comprises at least 4, at least 5, least 6, at least 7, or at least 8 first fusion polypeptides.

[0118] In some embodiments, the self-assembled polypeptide complex comprises at least 4, at least 5, least 6, at least 7, or at least 8 second fusion polypeptides.

[0119] In some embodiments, the self-assembled polypeptide complex further comprises at least 4, at least 5, least 6, at least 7, at least 8, at least 9, at least 10, least 11, at least 12, at least 13, at least 14, at least 15, or at least 16 third fusion polypeptides.

[0120] In some embodiments, the self-assembled polypeptide complex comprises a ratio of approximately 1:1, 1:2, 1:3, or 1:4 of first fusion polypeptides to all other fusion polypeptides. Multispecificity

[0121] In certain embodiments, a provided self-assembled polypeptide complex is multispecific. For example, in some embodiments, provided self-assembled polypeptide complexes comprise more than one type of HIV-1 binding fusion polypeptide, each HIV-1 binding fusion polypeptide comprising a different HIV-1 binding moiety (e.g., at least two, atleast three, or at least four different HIV-1 binding moieties). In some such self-assembled polypeptide complexes, the different HIV-1 binding moieties bind to different epitopes on HIV-1, e.g., different epitopes on HIV-1 Env, e.g., an epitope selected from the group consisting of the V1 / V2 apex, the V3 glycan, the CD4 binding site, the gp120-g41 interface, and the silent face. In some embodiments, the self-assembled polypeptide complexes collectively binds to at least two, at least three, or at least four different HIV-1 epitopes, such as at least two, at least three, or at least four different HIV-1 epitopes on HIV-1 Env.

[0122] In some embodiments, if two of the HIV-1 binding moieties are fragments of PGDM1400 and 10E8v4, then none of the HIV-1 binding moieties are fragments of N49P7 or iMab. Activity

[0123] In some embodiments, provided self-assembled polypeptide complex exhibits neutralizing activity against HIV-1. Neutralizing activity can be measured by any of a variety of methods known in the art, such as with the use of pseudovirus panels as described in Examples 1 and 2.

[0124] As used herein, the “reference HIV-1 pseudovirus panel” is the 119 pseudovirus (PsV) HIV-1 panel which has been described collectively in Seaman MS, et al., “Tiered categorization of a diverse panel of HIV-1 Env pseudoviruses for assessment of neutralizing antibodies.” J Virol.2010 Feb;84(3):1439-52 (which describes a panel of 109 molecularly cloned HIV-1 Env pseudoviruses representing a broad range of genetic and geographic diversity) and Pace CS, et al. “Bispecific antibodies directed to CD4 domain 2 and HIV envelope exhibit exceptional breadth and picomolar potency against HIV-1.” Proc Natl Acad Sci U S A.2013 Aug 13;110(33):13540-5) (which describes an expanded version of the panel in the Seaman et al. paper).

[0125] When neutralizing activity is determined using a panel, a median IC80 value can be determined based on the IC80values of a given test agent (e.g., a self-assembled polypeptide complex as provided herein, or a suitable control). In some embodiments, provided self- assembled polypeptide complexes exhibit neutralizing activity against HIV-1 with a median IC80 below 5 ng / mL, below 4 ng / mL, below 3 ng / mL, below 2 ng / mL, or below 1 ng / mL, when neutralizing activity is assessed using the reference HIV-1 pseudovirus panel.

[0126] In some embodiments, provided self-assembled polypeptide complexes are capable of neutralizing at least 98%, at least 99%, at least 99.5%, or 100% of the pseudoviruses in the reference HIV-1 pseudovirus panel at an IC80cutoff of < 10 µg / mL.

[0127] In some embodiments, provided self-assembled polypeptide complexes are capable of neutralizing at least 88%, at least 90%, at least 92.5%, at least 95%, at least 97%, at least 97.5%, at least 98%, or at least 99% of the pseudoviruses in the reference HIV-1 pseudovirus panel at an IC80cutoff of < 1.0 µg / mL.

[0128] In some embodiments, provided self-assembled polypeptide complexes are capable of neutralizing at least 82%, at least 85%, at least 87.5%, at least 90%, at least 92.5%, at least 95%, at least 97.5%, or at least 98% of the pseudoviruses in the reference HIV-1 pseudovirus panel at an IC80 cutoff of < 0.1 µg / mL.

[0129] In some embodiments, provided self-assembled polypeptide complexes are capable of neutralizing at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, or at least 92%, of the pseudoviruses in the reference HIV-1 pseudovirus panel at an IC80 cutoff of < 0.01 µg / mL. C. Compositions

[0130] In one aspect, provided are compositions comprising a self-assembled polypeptide complex or fusion polypeptide as described herein. Provided compositions may further comprising a pharmaceutically acceptable excipient, examples of which are known in the art. As a non-limiting example, a buffer such as a saline buffer may be suitable for use in a liquid composition.

[0131] Compositions may be formulated especially for the route of administration. D. Methods of treatment

[0132] In one aspect, provided are methods that may be useful for treating, ameliorating, or preventing HIV-1 infection and / or an HIV-1-associated condition, generally comprising a step of administering a composition comprising a self-assembled polypeptide complex of the present disclosure to a subject.

[0133] In one aspect, provided are uses of self-assembled polypeptide complexes or pharmaceutical compositions described herein for treating and / or preventing HIV-1 infection and / or an HIV-1-associated condition. In one aspect, provided are self-assembled polypeptide complexes and pharmaceutical compositions for use in treating and / or preventing HIV-1 infection and / or an HIV-1-associated condition.

[0134] Examples of HIV-associated conditions include acquired immunodeficiency, an opportunistic infection, or a cancer (e.g., cervical cancer, Kaposi sarcoma, lymphomas) which may occur in a subject infected with HIV-1.

[0135] In some embodiments, the subject is a mammal, e.g., a human.

[0136] Compositions for administration to subjects generally comprise a self-assembled polypeptide complex as disclosed herein. In some embodiments, such compositions further comprise a pharmaceutically acceptable excipient.

[0137] Compositions may be formulated for administration for any of a variety of routes of administration, including systemic routes (e.g., oral, intravenous, intraperitoneal, subcutaneous, or intramuscular administration). EXAMPLES Example 1. Epitope dependency of neutralization potency boosts in Multabodies (MBs)

[0138] Previously, the inventors had shown that multimerizing broadly-neutralizing antibodies (bnAbs) against HIV-1 into a monospecific Multabody (MB) format can result in 4- to 40-fold increase in potency against HIV-1 pseudoviruses, relative to the bnAbs in IgG format. In particular, the inventors previously showed that V1 / V2 and V3 bnAbs exhibited boosts in neutralization when assembled as MBs, whereas CD4b and membrane-proximal external region (MPER) bnAbs only showed modest or no improvement in potency when assembled as MBs, and only when assembled as 20-24-mer MBs.

[0139] The present Example further explored whether the boosts in potency against HIV-1 were epitope-dependent. Monospecific MBs were generated against each of four epitope classes (V1 / V2 apex, V3 glycan, CD4 binding site (“CD4bs”), and gp120-gp41 interface) within the HIV-1 envelope protein (HIV-1 Env), and their activities were assessed in HIV-1 pseudovirus panels. (See FIG.3 for a depiction of the epitopes on HIV-1 Env.) Materials and Methods

[0140] Multabody generation. Fusion proteins were generated by fusing together a human ferritin light chain (hFTL, SEQ ID NO:1) with a single-chain Fab (scFab) of an HIV-1 bnAb via a (Glyn-Ser)m peptide linker as described herein.

[0141] Genes encoding the light chain of human apoferritin and the scFab-human apoferritin fusions were synthesized and cloned by GeneArt (Life Technologies) into the pHLsec or pcDNA3.4 expression vector.200 mL of HEK 293F cells (Thermo FisherScientific) were seeded at a density of 0.8 x 106cells / mL in Freestyle expression media and incubated with 125 rpm oscillation at 37 ºC, 8% CO2, and 70% humidity in a Multitron Pro shaker (Infors HT). Within 24 h of seeding, cells were transiently transfected using 50 μg of filtered DNA preincubated for 10 min at room temperature (RT) with a transfection reagent (e.g., FectoPRO (Polyplus Transfections) at a 1:1 ratio or polyethylenimine “Max” (“PEI Max”) transfection reagent (Polysciences, Inc.)). For 12-mer MBs, plasmids encoding scFab- human apoferritin (light chain) and human apoferritin (light chain) were mixed at a ratio of 1:1. For 24-mer MBs, only plasmids encoding scFab-human apoferritin (light chain) were used. After 6-7 days, cell suspensions were harvested by centrifugation at 5000 ×g for 15 min and the supernatants filtered through a 0.22 μm Steritop filter (EMD Millipore). The particles were purified by affinity chromatography to the Fab and eluted after a wash. Fractions containing protein were pooled, concentrated and loaded onto a Superose 610 / 300 GL size exclusion column (GE Healthcare) in 20 mM sodium phosphate, pH 8.0, 150 mM NaCl.

[0142] scFabs of the following HIV-1 bnAbs were used for each epitope class as shown in Table 2: Table 2: Epitope classes, HIV-1 bnAbs, and valencies of produced MBs Epitope class HIV-1 bnAb(s) Valency of MBs produced V1 / V2 apex PGDM1400 12-mers and 24-mers ePGDM1400v9 12-mers and 24-mers V3 glycan ePGT121 12-mers 10-1074 12-mers and 24-mers DH270.6 12-mers AIIMS-P01 12-mers CD4bs N49P7 12-mers and 24-mers N49P9.7FR 12-mers N49P9.6FR 12-mers N49P7.6FR3-VHv10 12-mers N49P9.6-FR3-VHv8 12-mers N6 12-mers VRC07 12-mers 1-18 12-mersgp120-gp41 PGT151 12-mers interface silent face SF12 12-mers • ePGT121, ePGDM1400v9, N49P7.6FR3-VHv10, and N49P9.6-FR3-VHv8 were obtained with permission from the Scripps Research Institute and the International AIDS Vaccine Initiative (IAVI). • N49P7, N49P9.7FR, and N49P9.6FR were obtained with permission from the University of Maryland.

[0143] Neutralization assays. Pseudovirus (PsV) panels were generated by cotransfecting 293T cells with HIV-1 Env expression plasmids. Neutralization was determined in a single- cycle neutralization assay using the standard TZM-bl neutralization assay (Montefiori D. C., Measuring HIV neutralization in a luciferase reporter gene assay. Methods Mol. Biol.485, 395–405 (2009)). IgGs and Multabodies were incubated with a 10 to 15% tissue culture infectious dose of PsV for 1 h at 37 °C prior to a 44- to 72-h incubation with TZM-bl cells. Virus neutralization was monitored by either (1) adding Britelite plus reagent (PerkinElmer) to the cells and measuring luminescence in relative light units using a Synergy Neo2 Multi- Mode Assay Microplate Reader (BioTek Instruments) or (2) quantifying luciferase expression 48 h after infection upon cell lysis and addition of luciferin substrate (Promega).

[0144] MBs were tested against pseudovirus panels specific for the epitope class, as shown in Table 3 below. PsVs for each epitope class were selected for screening based on medium sensitivity (IC80^ 0.1-1 µg / mL) to bnAbs with that epitope class. Table 3: Pseudoviruses in panels tested for each epitope class Epitope class Pseudovirus panel V1 / V2 apex PVO.04, Q461, T266, X1193, Ch119, and A03349M1.vrc4a V3 glycan 3817.V2.c59, 16845-2.22, SC422661.8, DU422.1, QH0692.42, and PVO.04 CD4bs 3817.V2.c59, CAAN5342.A2, T257-31, and PVO.04 gp120-gp41 interface CAAN5342.A2, REJO, Q23.17, and P0402.c2.11 or silent face Results

[0145] MBs made using scFabs from bnAbs against the V1 / V2 apex (“V1 / V2 apex MBs) demonstrated boosts in potency relative to their corresponding bnAbs. ePGDM1400v9-based MBs exhibited at least comparable, but generally better boosts in potency than did PGDM1400-based MBs. Greater boosts in potency were observed with 24-mer MBs as compared to 12-mer MBs. (See FIGs.4A and 4B).

[0146] Of the MBs made using scFabs from bnAbs against the V3 glycan (“V3 glycan MBs”), ePGT121-based MBs exhibited the greatest boost in potency, with more than 3-fold and up to 40-fold improvements on most of the PsVs tested. Other MBs tested in this epitope class showed modest boosts on only one or two of the PsVs tested. For 10-1074, which was tested as both as 12-mer and a 24-mer MB, no significant improvement in potency was observed with the 24-mer MB as compared to the 12-mer MB. (See FIGs.4C and 4D.)

[0147] Overall, MBs made using scFabs from bnAbs against CD4bs, the gp120-gp41 interface or the silent face (“CD4bs MBs,” “gp120-gp41 MBs,” and “silent face MBs” respectively) did not exhibit boosts in potency across the PsVs tested. In many cases, the corresponding IgGs exhibited better potency than the MBs. (See FIG.4E for results from the CD4bs MBs and FIG.4F for the results from the gp120-gp41 MBs and the silent face MBs.)

[0148] These results generally fit a pattern in which boosts in potency of monospecific MBs decrease along the length of the HIV envelope, with the monospecific MBs based on the epitopes closer to the viral membrane exhibiting less potency than those based on more distal epitopes. (See FIG.4G.) However, these results do not rule out using Fabs from CD4bs bnAbs, gp120-gp41 bnAbs, or silent face bnAbs in multispecific MBs which target multiple epitope classes. Example 2. Multabodies with improved potency against HIV-1 pseudoviruses

[0149] Previously, the inventors showed that trispecific MBs which incorporate scFabs based on three different HIV-1 bnAbs exhibited improved breadth and potency in pseudovirus (PsV)-based neutralization assays, as compared to individual IgGs or cocktails of corresponding IgGs. Moreover, the inventors have demonstrated that increasing the number of Fabs displayed using a MB format which employs fusion proteins comprising half-ferritin chains and Fabs resulted in further improvements in breadth and potency. A trispecific MB (ER33) using this format demonstrated broad neutralization of 83% of PsVs in a 119-PsV panel (Pace CS, et al. “Bispecific antibodies directed to CD4 domain 2 and HIV envelope exhibit exceptional breadth and picomolar potency against HIV-1.” Proc Natl Acad Sci U S A.2013 Aug 13;110(33):13540-5) with an IC80 cut-off of 1 µg / mL.

[0150] The present Example explored whether it was possible to improve further the activity of ER33 using Fabs based on different combinations of bnAbs. Materials and methods

[0151] Generation of Multabodies

[0152] Generation of ER33: Genes encoding fusion proteins (1) PGDM1400-hFTL (SEQ ID NO:27), (2) scFab of N49P7 fused to the N-terminus of N_hFTL (N49P7-N_hFTL (SEQ ID NO:29), and (3) an Fc monomer with M428L / N434S (“LS”) mutations fused to the C- terminus of 10E8-C_hFTL (10E8v4-C_hFTL-IgG1_LS, SEQ ID NO:33) were prepared, mixed at a molar ratio of 3:1:1, and transiently transfected into HEK 293F cells for the production and formation of ER33. See, FIG.1D. (10E8-C_hFTL contains the scFab of HIV- neutralizing antibody 10E8v4 fused to the N-terminus of C_hFTL. Thus, the construct 10E8v4-C_hFTL-Fc (SEQ ID NO:32) contains a C-half ferritin with the Fab3 at the N- terminus of the C-half ferritin and an Fc monomer at the C-terminus of the C-half ferritin.)

[0153] The Multabodies were purified using Protein A affinity chromatography, optionally followed by Protein L affinity chromatography. Fractions containing the Multabodies were concentrated and further purified by size-exclusion chromatography (SEC) in sodium phosphate buffer. After SEC purification, negative-stain electron microscopy (EM) and / or SEC with inline multi-angle light scattering (SEC-MALS) was used to evaluate the size the of the of the formed Multabodies.

[0154] Generation of additional MBs: Additional MBs (H03, H04, and H05) were generated substantially as described above for ER33, except a different combination of Fabs (collectively targeting the V1 / V2 apex, V3 glycan, and CD4bs epitope classes) was used.

[0155] The combinations used in the various MBs are as shown in Table 4. Thus, H03 is like ER33 except that the 10E8v4 Fabs are replaced with 10-1074. Similarly, H05 is like ER33, except that 10E8v4 Fabs are replace with ePGT121 (obtained with permission from the International AIDS Vaccine Initiative (IAVI)). H04 is like H05, except that N49P7 is replaced with N49P9.6FR (obtained with permission from University of Maryland). Table 4: Combinations of Fabs used in MBs MB bnAbs on which scFabs were based V1 / V2 apex V3 glycan CD4bs ER33 PGDM1400 10E8v4 N49P7 H03 PGDM1400 10-1074 N49P7H05 PGDM1400 ePGT121 N49P7 H04 PGDM1400 ePGT121 N49P9.6FR

[0156] Pseudovirus neutralization assays were performed substantially similarly as described in Example 1. A wider 119 HIV-1 PsV panel was also used for some experiments. (For information about the 119 PsV panel, see Seaman MS, et al., “Tiered categorization of a diverse panel of HIV-1 Env pseudoviruses for assessment of neutralizing antibodies.” J Virol. 2010 Feb;84(3):1439-52, which describes a panel of 109 molecularly cloned HIV-1 Env pseudoviruses representing a broad range of genetic and geographic diversity, and an expanded panel described in Pace CS, et al. “Bispecific antibodies directed to CD4 domain 2 and HIV envelope exhibit exceptional breadth and picomolar potency against HIV-1.” Proc Natl Acad Sci U S A.2013 Aug 13;110(33):13540-5).) Results

[0157] The H03, H04, and H05 trispecific MBs provided significant (2-12x-fold) enhancements in potency against PsVs used in the initial screen (Du422.1, 3817, and REJO) relative to the potencies observed with corresponding IgG cocktails. (See FIG.5A) Whereas ER33 MB has an IC80 > 10 µg / mL against 3817 and Du422.1 PsVs, each of the H03, H04, and H05 trispecific MBs demonstrated potencies at IC80< 1 µg / mL across all three PsVs tested in the initial screen.

[0158] For reference, below are published IC80 values for various bnAbs against certain PsVs. Table 5: Published IC80values of certain HIV-1 bnAbs PsV PGDM1400 N49P7 10E8v4 10-1074 ePGT121 N49P6FR Du422.1 >10 >50 1.88 0.15 0.18 0.18 3817 >50 35.52 N / A 1.40 7.20 0.69 REJO 0.01 0.02 1.69 >20 12.90 0.03

[0159] In the 119-PsV panel, the trispecific MBs exhibited ~50-100-fold improvements in median IC80values relative to their corresponding IgG cocktails. (See FIG.5B.) H03, H04, and H05 MBs provided significant enhancements in both breadth of neutralization (as shown in Table 6 below) and potency compared to ER33 MB. H04 MB had a median IC80 of < 1 ng / mL, demonstrating an IC80 of > 1 µg / mL for only one of the PsVs. As shown in FIG.5C,the neutralization breadth of H04 MB is comparable to that of ER33 MB at high concentrations. However, H04 achieves 100% neutralization breadth, whereas ER33 does not in the same assay. The neutralization breadth of H04 MB is considerably superior to that of ER33 MB at lower concentrations. Table 6: Percentage of PsVs neutralized in the 119-PsV panel IC80 cutoff ER33 H03 H05 H04 IC80< 10 µg / mL 97% 99% 99% 100% IC80< 1.0 µg / mL 88% 97% 99% 99% IC80< 0.1 µg / mL 80% 90% 95% 98% IC80 < 0.01 µg / mL 66% 64% 66% 92%

[0160] Compared to bnAbs that have entered the clinic, H04 MB exhibits remarkable neutralization. For example, using a cutoff of IC80< 1 µg / mL, H04 MB neutralizes > 99% of the PsVs in the 119-PsV panel. In the same panel, 1-18 neutralized about 80% of the PsVs. (See e.g., Schommers P, et al., “Restriction of HIV-1 Escape by a Highly Broad and Potent Neutralizing Antibody.” Cell.2020 Feb 6;180(3):471-489.e22 for IC80values of 1-18 and other bnAbs in the same PsV panel.) Using a cutoff of 0.01 µg / mL, H04 MB still neutralizes more than 92% of PsVs in this panel, compared to only about 0 to 5% for bnAbs in the clinic.

[0161] Thus, this Example demonstrates the improved potency and neutralization breadths of the presently disclosed MBs as compared to previously described MBs and to bnAbs currently in the clinic. Example 3. Low polyreactivity of HIV-1-neutralizing Multabodies

[0162] The polyreactivity of the trispecific H04 MB and of two monospecific MBs which contained subcomponents of H04 MB (monospecific PDGM1400 MB and monospecific N49P9.6FR MB) was studied by assessing binding to antigens cardiolipin, keyhole limpet haemocyanin (KLH), insulin, and dsDNA at 15 µg / mL.

[0163] No binding was detected in these experiments to any of the antigens tested for the H04 MB and for monospecific MBs comprising subcomponents of H04 MB. (See FIG.6.) H03, H05, and ER33 MBs and corresponding subcomponent monospecific MBs and IgGs were also tested and showed negligible binding to antigens tested at 15 µg / mL.

[0164] Thus, the presently disclosed MBs exhibit favorable developability characteristics in these experiments.Example 4. HIV-1-targeting Multabodies exhibit neutralizing ability against additional HIV-1 strains

[0165] The trispecific HIV-1-targeting MBs tested in Example 2 were further tested in a 24- pseudovirus subpanel representative of a 76-pseudovirus panel isolated from patients in placebo-controlled groups in the VRC01 Antibody Mediated Prevention (AMP) efficacy trials (Mkhize NN et al. “Neutralization profiles of HIV-1 viruses from the VRC01 Antibody Mediated Prevention (AMP) trials.” PLoS Pathog.2023 Jun 29;19(6):e1011469). This 24- pseudovirus subpanel is distinct from the 119-pseudovirus panel used in Example 2 and is more representative of currently circulating HIV-1 strains. Other than the pseudovirus panel, the materials and methods for these experiments were substantially as described in Example 2. Results

[0166] In this pseudovirus panel, the trispecific HIV-1-targeting MBs also exhibited ~7-60- fold improvements in median IC80 values relative to their corresponding IgG cocktails. (FIG. 7A.) Table 7 summarizes the percentage of pseudoviruses neutralized for each MB tested based on different IC80cutoffs. H04 exhibited 100% neutralization breadth with IC80cut off values of 0.1 ^g / mL or higher. (FIG.7B and Table 7.) Table 7: Percentage of PsVs neutralized in the 24-PsV panel IC80 cutoff ER33 H03 H05 H04 IC80< 10 µg / mL 88% 100% 100% 100% IC80< 1.0 µg / mL 83% 100% 100% 100% IC80 < 0.1 µg / mL 71% 75% 92% 100% IC80 < 0.01 µg / mL 42% 17% 25% 79%

[0167] These results further demonstrate that MBs of the present disclosure exhibit broad neutralization, including against an additional set of HIV-1 variants more reflective of currently circulating statins.Example 5. HIV-1-targeting Multabodies of different formats exhibit broad neutralizing ability

[0168] To examine the ability of the present disclosure’s MBs to neutralize virus when the MBs are constructed with different formats, two versions the H04 MB (henceforth, “H04.A” and “H04.D”) were generated and tested against the 119-PsV panel. (See Example 2.) H04.A has the format of the H04 MB generated and tested as described in Examples 2-4 (MB.v2 format; see FIG.2C, bottom row). H04.D has a MB format as shown in FIG.8.

[0169] Table 8 summarizes the percentage of pseudoviruses neutralized for H04.A (MB.v2) and for H04.D (MB.v1.2) based on different IC80 cutoffs. MBs of both formats demonstrated good neutralization at IC80cutoffs of 0.01 ^g / mL or greater, with the H04.A MB exhibiting 100% neutralization with an IC80cutoff of < 1 ^g / mL. (FIG.9 and Table 8.)

[0170] Table 8: Percentage of PsVs neutralized in the 119 PsV panel IC80 cutoff H04.A (MB.v2) H04 / D (v1.2MB) IC80 < 1.0 µg / mL 100% 98% IC80 < 0.1 µg / mL 98% 98% IC80< 0.01 µg / mL 92% 87%

[0171] These results demonstrate that the presently disclosed MBs can achieve broad neutralization in a variety of formats. SEQUENCE LISTING Underlining within sequences indicate linker sequences; bolding within sequences indicate ferritin or ferritin subunit sequences; boxed and bolded residues indicate residues that are mutated relative to a reference molecule, e.g. relative to an IgG1 Fc. SEQ ID NO: 1 hFTL MSSQIRQNYSTDVEAAVNSLVNLYLQASYTYLSLGFYFDRDDVALEGVSHFFRELAEEKREG YERLLKMQNQRGGRALFQDIKKPAEDEWGKTPDAMKAAMALEKKLNQALLDLHALGSARTDP HLCDFLETHFLDEEVKLIKKMGDHLTNLHRLGGPEAGLGEYLFERLTLRHDSEQ ID NO: 2 N_hFTL MSSQIRQNYSTDVEAAVNSLVNLYLQASYTYLSLGFYFDRDDVALEGVSHFFRELAEEKREG YERLLKMQNQRGGRALFQDIKKPAEDEW SEQ ID NO: 3 C_hFTL GKTPDAMKAAMALEKKLNQALLDLHALGSARTDPHLCDFLETHFLDEEVKLIKKMGDHLTNL HRLGGPEAGLGEYLFERLTLRHD SEQ ID NO: 4 C_hFTL R / K Variant GKTPDAMKAAMALEKKLNQALLDLHALGSARTDPHLCDFLETHFLDEEVKLIKKMGDHLTNL HRLGGPEAGLGEYLFERLTLKHD SEQ ID NO: 5 IgG1 Fc DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGV EVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPR EPQVYTLPPSREEMTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFL YSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGK SEQ ID NO:6 IgG1 scFc DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGV EVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPR EPQVYTLPPSREEMTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFL YSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGKGGGGSGGGGSGGGGSGGGGSG GGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGDKTHTCPPCPAPEL LGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQY NSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSREEM TKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQG NVFSCSVMHEALHNHYTQKSLSLSPGK SEQ ID NO: 7 Mouse IgG2a Fc KPCPPCKCPAPNLLGGPSVFIFPPKIKDVLMISLSPIVTCVVVDVSEDDPDVQISWFVNNVE VHTAQTQTHREDYNSTLRVVSALPIQHQDWMSGKEFKCKVNNKDLPAPIERTISKPKGSVRA PQVYVLPPPEEEMTKKQVTLTCMVTDFMPEDIYVEWTNNGKTELNYKNTEPVLDSDGSYFMY SKLRVEKKNWVERNSYSCSVVHEGLHNHHTTKSFSRTPGKSEQ ID NO: 8 IgG2 scFc VECPPCPAPPVAGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVQFNWYVDGVEVHN AKTKPREEQFNSTFRVVSVLTVVHQDWLNGKEYKCKVSNKGLPAPIEKTISKTKGQPREPQV YTLPPSREEMTKNQVSLTCLVKGFYPSDISVEWESNGQPENNYKTTPPMLDSDGSFFLYSKL TVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGKGGGGSGGGGSGGGGSGGGGSGGGGS GGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGVECPPCPAPPVAGPSVFL FPPKPKDTLMISRTPEVTCVVVDVSHEDPEVQFNWYVDGVEVHNAKTKPREEQFNSTFRVVS VLTVVHQDWLNGKEYKCKVSNKGLPAPIEKTISKTKGQPREPQVYTLPPSREEMTKNQVSLT CLVKGFYPSDISVEWESNGQPENNYKTTPPMLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVM HEALHNHYTQKSLSLSPGK SEQ ID NO: 9 IgG4 Fc KYGPPCPSCPAPEFLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSQEDPEVQFNWYVDGV EVHNAKTKPREEQFNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKGLPSSIEKTISKAKGQPR EPQVYTLPPSQEEMTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFL YSRLTVDKSRWQEGNVFSCSVMHEALHNHYTQKSLSLSLGK SEQ ID NO: 10 IgG4 scFc KYGPPCPSCPAPEFLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSQEDPEVQFNWYVDGV EVHNAKTKPREEQFNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKGLPSSIEKTISKAKGQPR EPQVYTLPPSQEEMTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFL YSRLTVDKSRWQEGNVFSCSVMHEALHNHYTQKSLSLSLGKGGGGSGGGGSGGGGSGGGGSG GGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGKYGPPCPSCPAPEF LGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSQEDPEVQFNWYVDGVEVHNAKTKPREEQF NSTYRVVSVLTVLHQDWLNGKEYKCKVSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQEEM TKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQEG NVFSCSVMHEALHNHYTQKSLSLSLGK SEQ ID NO: 11 PGDM1400 IgG1 HC QAQLVQSGPEVRKPGTSVKVSCKAPGNTLKTYDLHWVRSVPGQGLQWMGWISHEGDKKVIVE RFKAKVTIDWDRSTNTAYLQLSGLTSGDTAVYYCAKGSKHRLRDYALYDDDGALNWAVDVDY LSNLEFWGQGTAVTVSSASTKGPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGA LTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDKKVEPKSCDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHN AKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQV YTLPPSREEMTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKL TVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGK SEQ ID NO: 12 PGDM1400 LC DFVLTQSPHSLSVTPGESASISCKSSHSLIHGDRNNYLAWYVQKPGRSPQLLIYLASSRASG VPDRFSGSGSDKDFTLKISRVETEDVGTYYCMQGRESPWTFGQGTKVDIKRTVAAPSVFIFP PSDEQLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTL SKADYEKHKVYACEVTHQGLSSPVTKSFNRGEC SEQ ID NO: 13 PGDM1400 HC (Fab) QAQLVQSGPEVRKPGTSVKVSCKAPGNTLKTYDLHWVRSVPGQGLQWMGWISHEGDKKVIVE RFKAKVTIDWDRSTNTAYLQLSGLTSGDTAVYYCAKGSKHRLRDYALYDDDGALNWAVDVDY LSNLEFWGQGTAVTVSSASTKGPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGA LTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDKKVEPKSC SEQ ID NO: 14 PGDM1400 scFab DFVLTQSPHSLSVTPGESASISCKSSHSLIHGDRNNYLAWYVQKPGRSPQLLIYLASSRASG VPDRFSGSGSDKDFTLKISRVETEDVGTYYCMQGRESPWTFGQGTKVDIKRTVAAPSVFIFP PSDEQLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTL SKADYEKHKVYACEVTHQGLSSPVTKSFNRGECGGGGSGGGGSGGGGSGGGGSGGGGSGGGG SGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSQAQLVQSGPEVRKPGTSVKVS CKAPGNTLKTYDLHWVRSVPGQGLQWMGWISHEGDKKVIVERFKAKVTIDWDRSTNTAYLQL SGLTSGDTAVYYCAKGSKHRLRDYALYDDDGALNWAVDVDYLSNLEFWGQGTAVTVSSASTK GPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLS SVVTVPSSSLGTQTYICNVNHKPSNTKVDKKVEPKSC SEQ ID NO: 15 N49P7 IgG1 HC ADLVQSGAVVKKPGDSVRISCEAQGYRFPDYIIHWIRRAPGQGPEWMGWMNPMGGQVNIPWK FQGRVSMTRDTSIETAFLDLRGLKSDDTAVYYCVRDRSNGSGKRFESSNWFLDLWGRGTAVT IQSASTKGPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQS SGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDKKVEPKSCDKTHTCPPCPAPELLGGP SVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSREEMTKNQ VSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFS CSVMHEALHNHYTQKSLSLSPGK SEQ ID NO: 16 N49P7 LC QSALTQPRSVSASPGQSVTISCTGTHNLVSWCQHQPGRAPKLLIYDFNKRPSGVPDRFSGSG SGGTASLTITGLQDDDDAEYFCWAYEAFGGGTKLTVLGQPKAAPSVTLFPPSSEELQANKAT LVCLISDFYPGAVTVAWKADSSPVKAGVETTTPSKQSNNKYAASSYLSLTPEQWKSHRSYSC QVTHEGSTVEKTVAPTEC SEQ ID NO: 17 N49P7 HC (Fab) ADLVQSGAVVKKPGDSVRISCEAQGYRFPDYIIHWIRRAPGQGPEWMGWMNPMGGQVNIPWK FQGRVSMTRDTSIETAFLDLRGLKSDDTAVYYCVRDRSNGSGKRFESSNWFLDLWGRGTAVT IQSASTKGPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQS SGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDKKVEPKSC SEQ ID NO: 18 N49P7 scFab QSALTQPRSVSASPGQSVTISCTGTHNLVSWCQHQPGRAPKLLIYDFNKRPSGVPDRFSGSG SGGTASLTITGLQDDDDAEYFCWAYEAFGGGTKLTVLGQPKAAPSVTLFPPSSEELQANKAT LVCLISDFYPGAVTVAWKADSSPVKAGVETTTPSKQSNNKYAASSYLSLTPEQWKSHRSYSC QVTHEGSTVEKTVAPTECGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGG SGGGGSGGGGSGGGGSGGGGSGGGGSADLVQSGAVVKKPGDSVRISCEAQGYRFPDYIIHWI RRAPGQGPEWMGWMNPMGGQVNIPWKFQGRVSMTRDTSIETAFLDLRGLKSDDTAVYYCVRD RSNGSGKRFESSNWFLDLWGRGTAVTIQSASTKGPSVFPLAPSSKSTSGGTAALGCLVKDYF PEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVD KKVEPKSC SEQ ID NO: 19 10E8v4 IgG1 HC EVRLVESGGGLVKPGGSLRLSCSASGFDFDNAWMTWVRQPPGKGLEWVGRITGPGEGWSVDY AESVKGRFTISRDNTKNTLYLEMNNVRTEDTGYYFCARTGKYYDFWSGYPPGEEYFQDWGQG TLVIVSSASTKGPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPA VLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDKKVEPKSCDKTHTCPPCPAPEL LGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQY NSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQG NVFSCSVMHEALHNHYTQKSLSLSPGK SEQ ID NO: 20 10E8v4 LC SELTQDPAVSVALKQTVTITCRGDSLRSHYASWYQKKPGQAPVLLFYGKNNRPSGIPDRFSG SASGNRASLTITGAQAEDEADYYCSSRDKSGSRLSVFGGGTKLTVLSQPKAAPSVTLFPPSS EELQANKATLVCLISDFYPGAVTVAWKADSSPVKAGVETTTPSKQSNNKYAASSYLSLTPEQ WKSHRSYSCQVTHEGSTVEKTVAPTECS SEQ ID NO: 21 10E8v4 HC (Fab) EVRLVESGGGLVKPGGSLRLSCSASGFDFDNAWMTWVRQPPGKGLEWVGRITGPGEGWSVDY AESVKGRFTISRDNTKNTLYLEMNNVRTEDTGYYFCARTGKYYDFWSGYPPGEEYFQDWGQG TLVIVSSASTKGPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPA VLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDKKVEPKSC SEQ ID NO: 22 10E8v4 scFab SELTQDPAVSVALKQTVTITCRGDSLRSHYASWYQKKPGQAPVLLFYGKNNRPSGIPDRFSG SASGNRASLTITGAQAEDEADYYCSSRDKSGSRLSVFGGGTKLTVLSQPKAAPSVTLFPPSS EELQANKATLVCLISDFYPGAVTVAWKADSSPVKAGVETTTPSKQSNNKYAASSYLSLTPEQ WKSHRSYSCQVTHEGSTVEKTVAPTECGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGS GGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSEVRLVESGGGLVKPGGSLRLSCSASGF DFDNAWMTWVRQPPGKGLEWVGRITGPGEGWSVDYAESVKGRFTISRDNTKNTLYLEMNNVR TEDTGYYFCARTGKYYDFWSGYPPGEEYFQDWGQGTLVIVSSASTKGPSVFPLAPSSKSTSG GTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYI CNVNHKPSNTKVDKKVEPKSC SEQ ID NO: 23 iMab IgG1 HC QVQLQQSGPEVVKPGASVKMSCKASGYTFTSYVIHWVRQKPGQGLDWIGYINPYNDGTDYDE KFKGKATLTSDTSTSTAYMELSSLRSEDTAVYYCAREKDNYATGAWFAYWGQGTLVTVSSAS TKGPSVFPLAPCSRSTSESTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYS LSSVVTVPSSSLGTKTYTCNVDHKPSNTKVDKRVESKYCDKTHTCPPCPAPELLGGPSVFLF PPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSV LTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSREEMTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMH EALHNHYTQKSLSLSPGK SEQ ID NO: 24 iMab LC DIVMTQSPDSLAVSLGERVTMNCKSSQSLLYSTNQKNYLAWYQQKPGQSPKLLIYWASTRES GVPDRFSGSGSGTDFTLTISSVQAEDVAVYYCQQYYSYRTFGGGTKLEIKRTVAAPSVFIFP PSDEQLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTL SKADYEKHKVYACEVTHQGLSSPVTKSFNRGEC SEQ ID NO: 25 iMab HC (Fab) QVQLQQSGPEVVKPGASVKMSCKASGYTFTSYVIHWVRQKPGQGLDWIGYINPYNDGTDYDE KFKGKATLTSDTSTSTAYMELSSLRSEDTAVYYCAREKDNYATGAWFAYWGQGTLVTVSSAS TKGPSVFPLAPCSRSTSESTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYS LSSVVTVPSSSLGTKTYTCNVDHKPSNTKVDKRVESKYC SEQ ID NO: 26 iMab scFab DIVMTQSPDSLAVSLGERVTMNCKSSQSLLYSTNQKNYLAWYQQKPGQSPKLLIYWASTRES GVPDRFSGSGSGTDFTLTISSVQAEDVAVYYCQQYYSYRTFGGGTKLEIKRTVAAPSVFIFP PSDEQLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTL SKADYEKHKVYACEVTHQGLSSPVTKSFNRGECGGGGSGGGGSGGGGSGGGGSGGGGSGGGG SGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSQVQLQQSGPEVVKPGASVKMS CKASGYTFTSYVIHWVRQKPGQGLDWIGYINPYNDGTDYDEKFKGKATLTSDTSTSTAYMEL SSLRSEDTAVYYCAREKDNYATGAWFAYWGQGTLVTVSSASTKGPSVFPLAPSSKSTSGGTA ALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNV NHKPSNTKVDKKVEPKSC SEQ ID NO: 27 PGDM1400-hFTL DFVLTQSPHSLSVTPGESASISCKSSHSLIHGDRNNYLAWYVQKPGRSPQLLIYLASSRASG VPDRFSGSGSDKDFTLKISRVETEDVGTYYCMQGRESPWTFGQGTKVDIKRTVAAPSVFIFP PSDEQLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTL SKADYEKHKVYACEVTHQGLSSPVTKSFNRGECGGGGSGGGGSGGGGSGGGGSGGGGSGGGG SGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSQAQLVQSGPEVRKPGTSVKVS CKAPGNTLKTYDLHWVRSVPGQGLQWMGWISHEGDKKVIVERFKAKVTIDWDRSTNTAYLQL SGLTSGDTAVYYCAKGSKHRLRDYALYDDDGALNWAVDVDYLSNLEFWGQGTAVTVSSASTKGPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLS SVVTVPSSSLGTQTYICNVNHKPSNTKVDKKVEPKSCDGGGGSGGGGSGGGGSGGGGSGGGG SGGSSQIRQNYSTDVEAAVNSLVNLYLQASYTYLSLGFYFDRDDVALEGVSHFFRELAEEKR EGYERLLKMQNQRGGRALFQDIKKPAEDEWGKTPDAMKAAMALEKKLNQALLDLHALGSART DPHLCDFLETHFLDEEVKLIKKMGDHLTNLHRLGGPEAGLGEYLFERLTLRHD SEQ ID NO: 28 N49P7-C_hFTL QSALTQPRSVSASPGQSVTISCTGTHNLVSWCQHQPGRAPKLLIYDFNKRPSGVPDRFSGSG SGGTASLTITGLQDDDDAEYFCWAYEAFGGGTKLTVLGQPKAAPSVTLFPPSSEELQANKAT LVCLISDFYPGAVTVAWKADSSPVKAGVETTTPSKQSNNKYAASSYLSLTPEQWKSHRSYSC QVTHEGSTVEKTVAPTECGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGG SGGGGSGGGGSGGGGSGGGGSGGGGSADLVQSGAVVKKPGDSVRISCEAQGYRFPDYIIHWI RRAPGQGPEWMGWMNPMGGQVNIPWKFQGRVSMTRDTSIETAFLDLRGLKSDDTAVYYCVRD RSNGSGKRFESSNWFLDLWGRGTAVTIQSASTKGPSVFPLAPSSKSTSGGTAALGCLVKDYF PEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVD KKVEPKSCGGGGSGGGGSGGGGSGGGGSGGGGSGGGKTPDAMKAAMALEKKLNQALLDLHAL GSARTDPHLCDFLETHFLDEEVKLIKKMGDHLTNLHRLGGPEAGLGEYLFERLTLRHD SEQ ID NO: 29 N49P7-N_hFTL QSALTQPRSVSASPGQSVTISCTGTHNLVSWCQHQPGRAPKLLIYDFNKRPSGVPDRFSGSG SGGTASLTITGLQDDDDAEYFCWAYEAFGGGTKLTVLGQPKAAPSVTLFPPSSEELQANKAT LVCLISDFYPGAVTVAWKADSSPVKAGVETTTPSKQSNNKYAASSYLSLTPEQWKSHRSYSC QVTHEGSTVEKTVAPTECGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGG SGGGGSGGGGSGGGGSGGGGSGGGGSADLVQSGAVVKKPGDSVRISCEAQGYRFPDYIIHWI RRAPGQGPEWMGWMNPMGGQVNIPWKFQGRVSMTRDTSIETAFLDLRGLKSDDTAVYYCVRD RSNGSGKRFESSNWFLDLWGRGTAVTIQSASTKGPSVFPLAPSSKSTSGGTAALGCLVKDYF PEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVD KKVEPKSCGGGGSGGGGSGGGGSGGGGSGGGGSGGSSQIRQNYSTDVEAAVNSLVNLYLQAS YTYLSLGFYFDRDDVALEGVSHFFRELAEEKREGYERLLKMQNQRGGRALFQDIKKPAEDEW SEQ ID NO: 30 10E8v4-C_hFTL SELTQDPAVSVALKQTVTITCRGDSLRSHYASWYQKKPGQAPVLLFYGKNNRPSGIPDRFSG SASGNRASLTITGAQAEDEADYYCSSRDKSGSRLSVFGGGTKLTVLSQPKAAPSVTLFPPSS EELQANKATLVCLISDFYPGAVTVAWKADSSPVKAGVETTTPSKQSNNKYAASSYLSLTPEQWKSHRSYSCQVTHEGSTVEKTVAPTECGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGS GGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSEVRLVESGGGLVKPGGSLRLSCSASGF DFDNAWMTWVRQPPGKGLEWVGRITGPGEGWSVDYAESVKGRFTISRDNTKNTLYLEMNNVR TEDTGYYFCARTGKYYDFWSGYPPGEEYFQDWGQGTLVIVSSASTKGPSVFPLAPSSKSTSG GTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYI CNVNHKPSNTKVDKKVEPKSCGGGGSGGGGSGGGGSGGGGSGGGGSGGGGKTPDAMKAAMAL EKKLNQALLDLHALGSARTDPHLCDFLETHFLDEEVKLIKKMGDHLTNLHRLGGPEAGLGEY LFERLTLRHD SEQ ID NO: 31 iMab-C_hFTL DIVMTQSPDSLAVSLGERVTMNCKSSQSLLYSTNQKNYLAWYQQKPGQSPKLLIYWASTRES GVPDRFSGSGSGTDFTLTISSVQAEDVAVYYCQQYYSYRTFGGGTKLEIKRTVAAPSVFIFP PSDEQLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTL SKADYEKHKVYACEVTHQGLSSPVTKSFNRGECGGGGSGGGGSGGGGSGGGGSGGGGSGGGG SGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSQVQLQQSGPEVVKPGASVKMS CKASGYTFTSYVIHWVRQKPGQGLDWIGYINPYNDGTDYDEKFKGKATLTSDTSTSTAYMEL SSLRSEDTAVYYCAREKDNYATGAWFAYWGQGTLVTVSSASTKGPSVFPLAPSSKSTSGGTA ALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNV NHKPSNTKVDKKVEPKSCGGGGSGGGGSGGGGSGGGGSGGGGSGGGGKTPDAMKAAMALEKK LNQALLDLHALGSARTDPHLCDFLETHFLDEEVKLIKKMGDHLTNLHRLGGPEAGLGEYLFE RLTLRHD SEQ ID NO: 32 10E8v4-C_hFTL-IgG1_Fc SELTQDPAVSVALKQTVTITCRGDSLRSHYASWYQKKPGQAPVLLFYGKNNRPSGIPDRFSG SASGNRASLTITGAQAEDEADYYCSSRDKSGSRLSVFGGGTKLTVLSQPKAAPSVTLFPPSS EELQANKATLVCLISDFYPGAVTVAWKADSSPVKAGVETTTPSKQSNNKYAASSYLSLTPEQ WKSHRSYSCQVTHEGSTVEKTVAPTECGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGS GGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSEVRLVESGGGLVKPGGSLRLSCSASGF DFDNAWMTWVRQPPGKGLEWVGRITGPGEGWSVDYAESVKGRFTISRDNTKNTLYLEMNNVR TEDTGYYFCARTGKYYDFWSGYPPGEEYFQDWGQGTLVIVSSASTKGPSVFPLAPSSKSTSG GTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYI CNVNHKPSNTKVDKKVEPKSCGGGGSGGGGSGGGGSGGGGSGGGGSGGGGKTPDAMKAAMAL EKKLNQALLDLHALGSARTDPHLCDFLETHFLDEEVKLIKKMGDHLTNLHRLGGPEAGLGEY LFERLTLRHDGGSGGSGGSGGSGGGSGGSGGSGGSGDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTV LHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSREEMTKNQVSLTCLVK GFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEAL HNHYTQKSLSLSPGK SEQ ID NO: 33 10E8v4-C_hFTL-IgG1_LS SELTQDPAVSVALKQTVTITCRGDSLRSHYASWYQKKPGQAPVLLFYGKNNRPSGIPDRFSG SASGNRASLTITGAQAEDEADYYCSSRDKSGSRLSVFGGGTKLTVLSQPKAAPSVTLFPPSS EELQANKATLVCLISDFYPGAVTVAWKADSSPVKAGVETTTPSKQSNNKYAASSYLSLTPEQ WKSHRSYSCQVTHEGSTVEKTVAPTECGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGS GGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSEVRLVESGGGLVKPGGSLRLSCSASGF DFDNAWMTWVRQPPGKGLEWVGRITGPGEGWSVDYAESVKGRFTISRDNTKNTLYLEMNNVR TEDTGYYFCARTGKYYDFWSGYPPGEEYFQDWGQGTLVIVSSASTKGPSVFPLAPSSKSTSG GTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYI CNVNHKPSNTKVDKKVEPKSCGGGGSGGGGSGGGGSGGGGSGGGGSGGGGKTPDAMKAAMAL EKKLNQALLDLHALGSARTDPHLCDFLETHFLDEEVKLIKKMGDHLTNLHRLGGPEAGLGEY LFERLTLRHDGGSGGSGGSGGSGGGSGGSGGSGGSGDKTHTCPPCPAPELLGGPSVFLFPPK PKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTV LHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSREEMTKNQVSLTCLVKHSHYTQKSLSLSPGK SEQ ID NO: 34 IgG1_scFc-N_hFTL DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGV EVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPR EPQVYTLPPSREEMTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFL YSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGKGGGGSGGGGSGGGGSGGGGSG GGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGDKTHTCPPCPAPEL LGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQY NSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSREEM TKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQG NVFSCSVMHEALHNHYTQKSLSLSPGKGGGGSGGGGSGGGGSGGGGSGGGGSGGSSQIRQNY STDVEAAVNSLVNLYLQASYTYLSLGFYFDRDDVALEGVSHFFRELAEEKREGYERLLKMQN QRGGRALFQDIKKPAEDEWSEQ ID NO: 35 IgG2_scFc-N_hFTL VECPPCPAPPVAGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVQFNWYVDGVEVHN AKTKPREEQFNSTFRVVSVLTVVHQDWLNGKEYKCKVSNKGLPAPIEKTISKTKGQPREPQV YTLPPSREEMTKNQVSLTCLVKGFYPSDISVEWESNGQPENNYKTTPPMLDSDGSFFLYSKL TVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGKGGGGSGGGGSGGGGSGGGGSGGGGS GGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGVECPPCPAPPVAGPSVFL FPPKPKDTLMISRTPEVTCVVVDVSHEDPEVQFNWYVDGVEVHNAKTKPREEQFNSTFRVVS VLTVVHQDWLNGKEYKCKVSNKGLPAPIEKTISKTKGQPREPQVYTLPPSREEMTKNQVSLT CLVKGFYPSDISVEWESNGQPENNYKTTPPMLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVM HEALHNHYTQKSLSLSPGKGGGGSGGGGSGGGGSGGGGSGGGGSGGSSQIRQNYSTDVEAAV NSLVNLYLQASYTYLSLGFYFDRDDVALEGVSHFFRELAEEKREGYERLLKMQNQRGGRALF QDIKKPAEDEW SEQ ID NO: 36 IgG4_scFc-N_hFTL KYGPPCPSCPAPEFLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSQEDPEVQFNWYVDGV EVHNAKTKPREEQFNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKGLPSSIEKTISKAKGQPR EPQVYTLPPSQEEMTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFL YSRLTVDKSRWQEGNVFSCSVMHEALHNHYTQKSLSLSLGKGGGGSGGGGSGGGGSGGGGSG GGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGKYGPPCPSCPAPEF LGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSQEDPEVQFNWYVDGVEVHNAKTKPREEQF NSTYRVVSVLTVLHQDWLNGKEYKCKVSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQEEM TKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQEG NVFSCSVMHEALHNHYTQKSLSLSLGKGGGGSGGGGSGGGGSGGGGSGGGGSGGSSQIRQNY STDVEAAVNSLVNLYLQASYTYLSLGFYFDRDDVALEGVSHFFRELAEEKREGYERLLKMQN QRGGRALFQDIKKPAEDEW SEQ ID NO: 37 IgG1_P329G_scFc-N_hFTL DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGV EVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALGAPIEKTISKAKGQPR EPQVYTLPPSREEMTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFL YSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGKGGGGSGGGGSGGGGSGGGGSG GGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGDKTHTCPPCPAPEL LGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALGAPIEKTISKAKGQPREPQVYTLPPSREEMNVFSCSVMHEALHNHYTQKSLSLSPGKGGGGSGGGGSGGGGSGGGGSGGGGSGGSSQIRQNY STDVEAAVNSLVNLYLQASYTYLSLGFYFDRDDVALEGVSHFFRELAEEKREGYERLLKMQN QRGGRALFQDIKKPAEDEW SEQ ID NO: 38 IgG1_LALA_scFc-N_hFTL DKTHTCPPCPAPEAAGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGV EVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPR EPQVYTLPPSREEMTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFL YSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGKGGGGSGGGGSGGGGSGGGGSG GGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGDKTHTCPPCPAPEA AGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQY NSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSREEM TKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQG NVFSCSVMHEALHNHYTQKSLSLSPGKGGGGSGGGGSGGGGSGGGGSGGGGSGGSSQIRQNY STDVEAAVNSLVNLYLQASYTYLSLGFYFDRDDVALEGVSHFFRELAEEKREGYERLLKMQN QRGGRALFQDIKKPAEDEW SEQ ID NO: 39 IgG1_LALAP_scFc-N_hFTL DKTHTCPPCPAPEAAGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGV EVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALGAPIEKTISKAKGQPR EPQVYTLPPSREEMTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFL YSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGKGGGGSGGGGSGGGGSGGGGSGNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALGAPIEKTISKAKGQPREPQVYTLPPSREEM TKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQG NVFSCSVMHEALHNHYTQKSLSLSPGKGGGGSGGGGSGGGGSGGGGSGGGGSGGSSQIRQNY STDVEAAVNSLVNLYLQASYTYLSLGFYFDRDDVALEGVSHFFRELAEEKREGYERLLKMQN QRGGRALFQDIKKPAEDEWSEQ ID NO: 40 IgG1_K288A_scFc-N_hFTL DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGV EVHNAATKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPR EPQVYTLPPSREEMTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFL YSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGKGGGGSGGGGSGGGGSGGGGSG GGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGDKTHTCPPCPAPELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQG NVFSCSVMHEALHNHYTQKSLSLSPGKGGGGSGGGGSGGGGSGGGGSGGGGSGGSSQIRQNY STDVEAAVNSLVNLYLQASYTYLSLGFYFDRDDVALEGVSHFFRELAEEKREGYERLLKMQN QRGGRALFQDIKKPAEDEWEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPR EPQVYTLPPSREEMTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFL YSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGKGGGGSGGGGSGGGGSGGGGSG GGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGDKTHTCPPCPAPEL LGGPSVFLFPPKPKDTLMASRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQY NSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSREEM TKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQG NVFSCSVMHEALHNHYTQKSLSLSPGKGGGGSGGGGSGGGGSGGGGSGGGGSGGSSQIRQNY STDVEAAVNSLVNLYLQASYTYLSLGFYFDRDDVALEGVSHFFRELAEEKREGYERLLKMQN QRGGRALFQDIKKPAEDEW SEQ ID NO: 42 IgG1_I253V_scFc-N_hFTL DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMVSRTPEVTCVVVDVSHEDPEVKFNWYVDGV EVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPR EPQVYTLPPSREEMTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFL YSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGKGGGGSGGGGSGGGGSGGGGSG GGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGDKTHTCPPCPAPEL LGGPSVFLFPPKPKDTLMVSRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSREEM TKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQG NVFSCSVMHEALHNHYTQKSLSLSPGKGGGGSGGGGSGGGGSGGGGSGGGGSGGSSQIRQNY STDVEAAVNSLVNLYLQASYTYLSLGFYFDRDDVALEGVSHFFRELAEEKREGYERLLKMQN QRGGRALFQDIKKPAEDEW SEQ ID NO: 43 N_hFTLEMTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQ QGNVFSCSVMHEALHNHYTQKSLSLSPGKGGGGSGGGGSGGGGSGGGGSGGGGSGGSSQIRQ NYSTDVEAAVNSLVNLYLQASYTYLSLGFYFDRDDVALEGVSHFFRELAEEKREGYERLLKM QNQRGGRALFQDIKKPAEDEW SEQ ID NO: 44 IgG1_LALAP_K288A_scFc-N_hFTL DKTHTCPPCPAPEAAGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGV EVHNAATKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALGAPIEKTISKAKGQP REPQVYTLPPSREEMTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFF LYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGKGGGGSGGGGSGGGGSGGGGSEMTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQ QGNVFSCSVMHEALHNHYTQKSLSLSPGKGGGGSGGGGSGGGGSGGGGSGGGGSGGSSQIRQ NYSTDVEAAVNSLVNLYLQASYTYLSLGFYFDRDDVALEGVSHFFRELAEEKREGYERLLKM QNQRGGRALFQDIKKPAEDEWSEQ ID NO: 45 IgG2_P329G_K288A_scFc-N_hFTL VECPPCPAPPVAGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVQFNWYVDGVEVHN AATKPREEQFNSTFRVVSVLTVVHQDWLNGKEYKCKVSNKGLGAPIEKTISKTKGQPREPQ VYTLPPSREEMTKNQVSLTCLVKGFYPSDISVEWESNGQPENNYKTTPPMLDSDGSFFLYSK LTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGKGGGGSGGGGSGGGGSGGGGSGGGG SGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGVECPPCPAPPVAGPSVFTCLVKGFYPSDISVEWESNGQPENNYKTTPPMLDSDGSFFLYSKLTVDKSRWQQGNVFSCSV MHEALHNHYTQKSLSLSPGKGGGGSGGGGSGGGGSGGGGSGGGGSGGSSQIRQNYSTDVEAA VNSLVNLYLQASYTYLSLGFYFDRDDVALEGVSHFFRELAEEKREGYERLLKMQNQRGGRAL FQDIKKPAEDEW SEQ ID NO: 46 IgG2 Fc VECPPCPAPPVAGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVQFNWYVDGVEVHN AKTKPREEQFNSTFRVVSVLTVVHQDWLNGKEYKCKVSNKGLPAPIEKTISKTKGQPREPQV YTLPPSREEMTKNQVSLTCLVKGFYPSDISVEWESNGQPENNYKTTPPMLDSDGSFFLYSKL TVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGK SEQ ID NO: 47 His tagged MPER peptide HHHHHHNEQELLELDKWASLWNWFNITNWLWYIKKKK SEQ ID NO: 48 Example GS repeat GGGS SEQ ID NO: 49 Example GS repeat GGGGS SEQ ID NOs: 50-145 are as shown in Table 1. EQUIVALENTS / OTHER EMBODIMENTS

[0172] While the invention has been described in connection with specific embodiments thereof, it will be understood that it is capable of further modifications and this application is intended to cover any variations, uses, or adaptations of the invention following, in general,the principles of the invention and including such departures from the present disclosure that come within known or customary practice within the art to which the invention pertains and may be applied to the essential features herein before set forth.

Claims

CLAIMS 1. A self-assembled polypeptide complex comprising (a) one or more first fusion polypeptides, each first fusion polypeptide comprising (1) an HIV-1-binding moiety linked to (2) a nanocage monomer or subunit thereof; and (b) one or more second fusion polypeptides, each second fusion polypeptide comprising (1) an Fc polypeptide linked to (2) a nanocage monomer or subunit thereof, wherein the self-assembled polypeptide complex exhibits neutralizing activity against HIV-1 with a median IC80below 5 ng / mL.

2. A self-assembled polypeptide complex comprising (a) one or more first fusion polypeptides, each first fusion polypeptide comprising (1) an HIV-1-binding moiety linked to (2) a nanocage monomer or subunit thereof; and (b) one or more second fusion polypeptides, each second fusion polypeptide comprising (1) an Fc polypeptide linked to (2) a nanocage monomer or subunit thereof, wherein the self-assembled polypeptide complex is capable of neutralizing at least 98% of the pseudoviruses in a reference HIV-1 pseudovirus panel at an IC80 cutoff of < 10 µg / mL.

3. The self-assembled polypeptide complex of claim 2, wherein the self-assembled polypeptide complex is capable of neutralizing at least 98% of the pseudoviruses in the reference HIV-1 pseudovirus panel at an IC80 cutoff of < 1.0 µg / mL.

4. The self-assembled polypeptide complex of claim 3, wherein the self-assembled polypeptide complex is capable of neutralizing at least 98% of the pseudoviruses in the reference HIV-1 pseudovirus panel at an IC80 cutoff of < 0.1 µg / mL.

5. A self-assembled polypeptide complex comprising (a) one or more first fusion polypeptides, each first fusion polypeptide comprising (1) a first HIV-1-binding moiety linked to (2) a nanocage monomer or subunit thereof; (b) one or more second fusion polypeptides, each second fusion polypeptide comprising (1) a second HIV-1-binding moiety linked to (2) a nanocage monomer or subunit thereof;(c) one or more third fusion polypeptides, each third fusion polypeptide comprising (1) a third HIV-1-binding moiety linked to (2) a nanocage monomer or subunit thereof; and (d) one or more fourth fusion polypeptides, each fourth fusion polypeptide comprising (1) an Fc polypeptide linked to (2) a nanocage monomer or subunit thereof, wherein the first, second, and third HIV-1-binding moieties are collectively capable of binding to three different epitope classes of the HIV-1 envelope protein, wherein if two of the HIV-1 binding moieties are fragments of PDGM1400 and 10E8v4, then none of the HIV-1 binding moieties are fragments of N49P7 or iMab.

6. The self-assembled polypeptide complex of claim 5, wherein the first, second, and third HIV-1-binding moieties are collectively capable of binding to the V1 / V2 interface, the V3 glycan, and the CD4 binding site on HIV-1 Env.

7. The self-assembled polypeptide complex of claim 5, wherein the first, second, and third HIV-1-binding moieties are collectively capable of binding to the V1 / V2 interface, the membrane-proximal external region (MPER), and the CD4 binding site on HIV-1 Env.

8. A fusion polypeptide comprising an HIV-1 binding antibody or HIV-1 binding fragment thereof linked to a nanocage monomer or subunit thereof, wherein the HIV-1 binding antibody or HIV-1 binding fragment thereof binds to an epitope selected from the group consisting of the gp140-gp41 interface and the silent face of HIV-1 Env.

9. A fusion polypeptide comprising an HIV-1-binding antibody or HIV-1 binding fragment thereof linked to a nanocage monomer or subunit thereof, wherein the HIV-1-binding antibody or HIV-1 binding fragment thereof comprises a heavy chain complementarity determining region 3 (CDR-H3) selected from the group consisting of SEQ ID NOs: 53, 61, 69, 77, 85, 93, 101, 109, 117, 125, 133, and 141, or a variant of the foregoing sequences which comprises no more than three, no more than two or no more than one amino acid substitution therefrom.

10. The fusion polypeptide of claim 9, wherein the HIV-1-binding antibody or HIV-1 binding fragment thereof comprises a heavy chain complementarity determining region 3 (CDR-H3) selected from the group consisting of SEQ ID NOs: 53, 61, 69, 77, 85, 93, 101, 109, 117, 125, 133, and 141.

11. The fusion polypeptide of claim 9 or 10, wherein the HIV-1-binding antibody or HIV- 1 binding fragment thereof comprises a CDR-H3 sequence and a CDR-L3 sequence of (a) SEQ ID NO: 53 and SEQ ID NO: 57, respectively, (b) SEQ ID NO: 61 and SEQ ID NO: 65, respectively,(c) SEQ ID NO: 69 and SEQ ID NO: 73, respectively, (d) SEQ ID NO: 77 and SEQ ID NO: 81, respectively, (e) SEQ ID NO: 85 and SEQ ID NO: 89, respectively, (f) SEQ ID NO: 93 and SEQ ID NO: 97, respectively, (g) SEQ ID NO: 101 and SEQ ID NO: 105, respectively, (h) SEQ ID NO: 109 and SEQ ID NO: 113, respectively, (i) SEQ ID NO: 117 and SEQ ID NO: 121, respectively, (j) SEQ ID NO: 125 and SEQ ID NO: 129, respectively, (k) SEQ ID NO: 133 and SEQ ID NO: 137, respectively, (l) SEQ ID NO: 141 and SEQ ID NO: 145, respectively, or (m) or a CDR-H3 sequence and a CDR-L3 sequence which collectively differ by no more than three, no more than two, or one amino acid substitutions across both CDR-H3 and CDR-L3 sequences of any of the foregoing (a)-(l).

12. The fusion polypeptide of claim 11 , wherein the HIV-1-binding antibody or HIV-1 binding fragment thereof comprises a CDR-H3 sequence and a CDR-L3 sequence of (a) SEQ ID NO: 53 and SEQ ID NO: 57, respectively, (b) SEQ ID NO: 61 and SEQ ID NO: 65, respectively, (c) SEQ ID NO: 69 and SEQ ID NO: 73, respectively, (d) SEQ ID NO: 77 and SEQ ID NO: 81, respectively, (e) SEQ ID NO: 85 and SEQ ID NO: 89, respectively, (f) SEQ ID NO: 93 and SEQ ID NO: 97, respectively, (g) SEQ ID NO: 101 and SEQ ID NO: 105, respectively, (h) SEQ ID NO: 109 and SEQ ID NO: 113, respectively, (i) SEQ ID NO: 117 and SEQ ID NO: 121, respectively, (j) SEQ ID NO: 125 and SEQ ID NO: 129, respectively, (k) SEQ ID NO: 133 and SEQ ID NO: 137, respectively, or (l) SEQ ID NO: 141 and SEQ ID NO: 145, respectively.

13. The fusion polypeptide of claim 11, wherein the HIV-1-binding antibody or HIV-1 binding fragment thereof comprises a heavy chain variable region comprising complementarity determining regions CDR-H1, CDR-H2, and CDR-H3, and a light chain variable region comprising complementarity determining regions CDR-L1, CDR-L2, and CDR-L3, having amino acid sequences of (a) SEQ ID NO: 51, 52, and 53 for CDR-H1, CDR-H2, and CDR-H3, respectively and SEQ ID NO: 55, 56, and 57 for CDR-L1, CDR-L2, and CDR-H3, respectively, (b) SEQ ID NO: 59, 60, and 61 for CDR-H1, CDR-H2, and CDR-H3, respectively and SEQ ID NO: 63, 64, and 65 for CDR-L1, CDR-L2, and CDR-H3, respectively, (c) SEQ ID NO: 67, 68, and 69 for CDR-H1, CDR-H2, and CDR-H3, respectively and SEQ ID NO: 71, 72, and 73 for CDR-L1, CDR-L2, and CDR-H3, respectively, (d) SEQ ID NO: 75, 76, and 77 for CDR-H1, CDR-H2, and CDR-H3, respectively and SEQ ID NO: 79, 80, and 81 for CDR-L1, CDR-L2, and CDR-H3, respectively, (e) SEQ ID NO: 83, 84, and 85 for CDR-H1, CDR-H2, and CDR-H3, respectively and SEQ ID NO: 87, 88, and 89 for CDR-L1, CDR-L2, and CDR-H3, respectively, (f) SEQ ID NO: 91, 92, and 93 for CDR-H1, CDR-H2, and CDR-H3, respectively and SEQ ID NO: 95, 96, and 97 for CDR-L1, CDR-L2, and CDR-H3, respectively, (g) SEQ ID NO: 99, 100, and 101 for CDR-H1, CDR-H2, and CDR-H3, respectively and SEQ ID NO: 103, 104, and 105 for CDR-L1, CDR-L2, and CDR-H3, respectively, (h) SEQ ID NO: 107, 108, and 109 for CDR-H1, CDR-H2, and CDR-H3, respectively and SEQ ID NO: 111, 112, and 113 for CDR-L1, CDR-L2, and CDR-H3, respectively, (i) SEQ ID NO: 115, 116, and 117 for CDR-H1, CDR-H2, and CDR-H3, respectively and SEQ ID NO: 119, 120, and 121 for CDR-L1, CDR-L2, and CDR-H3, respectively, (j) SEQ ID NO: 123, 124, and 125 for CDR-H1, CDR-H2, and CDR-H3, respectively and SEQ ID NO: 127, 128, and 129 for CDR-L1, CDR-L2, and CDR-H3, respectively, (k) SEQ ID NO: 131, 132, and 133 for CDR-H1, CDR-H2, and CDR-H3, respectively and SEQ ID NO: 135, 136, and 137 for CDR-L1, CDR-L2, and CDR-H3, respectively, (l) SEQ ID NO: 138, 139, and 140 for CDR-H1, CDR-H2, and CDR-H3, respectively and SEQ ID NO: 142, 143, and 144 for CDR-L1, CDR-L2, and CDR-H3, respectively, or(m) CDR-H1, CDR-H2, CDR-H3, CDR-L1, CDR-L2, and CDR-L3 sequences which collectively differ by no more than three, no more than two, or one amino acid substitutions across all six CDRs from any of the foregoing sequences in (a)-(l).

14. The fusion polypeptide of claim 12, wherein the HIV-1-binding antibody or HIV-1 binding fragment thereof comprises a heavy chain variable region comprising complementarity determining regions CDR-H1, CDR-H2, and CDR-H3, and a light chain variable region comprising complementarity determining regions CDR-L1, CDR-L2, and CDR-L3, having amino acid sequences of: (a) SEQ ID NO: 51, 52, and 53 for CDR-H1, CDR-H2, and CDR-H3, respectively and SEQ ID NO: 55, 56, and 57 for CDR-L1, CDR-L2, and CDR-H3, respectively, (b) SEQ ID NO: 59, 60, and 61 for CDR-H1, CDR-H2, and CDR-H3, respectively and SEQ ID NO: 63, 64, and 65 for CDR-L1, CDR-L2, and CDR-H3, respectively, (c) SEQ ID NO: 67, 68, and 69 for CDR-H1, CDR-H2, and CDR-H3, respectively and SEQ ID NO: 71, 72, and 73 for CDR-L1, CDR-L2, and CDR-H3, respectively, (d) SEQ ID NO: 75, 76, and 77 for CDR-H1, CDR-H2, and CDR-H3, respectively and SEQ ID NO: 79, 80, and 81 for CDR-L1, CDR-L2, and CDR-H3, respectively, (e) SEQ ID NO: 83, 84, and 85 for CDR-H1, CDR-H2, and CDR-H3, respectively and SEQ ID NO: 87, 88, and 89 for CDR-L1, CDR-L2, and CDR-H3, respectively, (f) SEQ ID NO: 91, 92, and 93 for CDR-H1, CDR-H2, and CDR-H3, respectively and SEQ ID NO: 95, 96, and 97 for CDR-L1, CDR-L2, and CDR-H3, respectively, (g) SEQ ID NO: 99, 100, and 101 for CDR-H1, CDR-H2, and CDR-H3, respectively and SEQ ID NO: 103, 104, and 105 for CDR-L1, CDR-L2, and CDR-H3, respectively, (h) SEQ ID NO: 107, 108, and 109 for CDR-H1, CDR-H2, and CDR-H3, respectively and SEQ ID NO: 111, 112, and 113 for CDR-L1, CDR-L2, and CDR-H3, respectively, (i) SEQ ID NO: 115, 116, and 117 for CDR-H1, CDR-H2, and CDR-H3, respectively and SEQ ID NO: 119, 120, and 121 for CDR-L1, CDR-L2, and CDR-H3, respectively, (j) SEQ ID NO: 123, 124, and 125 for CDR-H1, CDR-H2, and CDR-H3, respectively and SEQ ID NO: 127, 128, and 129 for CDR-L1, CDR-L2, and CDR-H3, respectively, (k) SEQ ID NO: 131, 132, and 133 for CDR-H1, CDR-H2, and CDR-H3, respectively and SEQ ID NO: 135, 136, and 137 for CDR-L1, CDR-L2, and CDR-H3, respectively, or(l) SEQ ID NO: 138, 139, and 140 for CDR-H1, CDR-H2, and CDR-H3, respectively and SEQ ID NO: 142, 143, and 144 for CDR-L1, CDR-L2, and CDR-H3, respectively.

15. The fusion polypeptide of claim 8, wherein the HIV-1-binding antibody or HIV-1 binding fragment thereof comprises a heavy chain variable region and a light chain variable region, each having amino acid sequences that are at least 85%, at least 90%, at least 92.5%, at least 95%, at least 97.5%, at least 98%, at least 99%, or 100% identical to the sequences of (a) SEQ ID NO: 50 and SEQ ID NO: 54, respectively, (b) SEQ ID NO: 58 and SEQ ID NO: 62, respectively, (c) SEQ ID NO: 66 and SEQ ID NO: 70, respectively, (d) SEQ ID NO: 74 and SEQ ID NO: 78, respectively, (e) SEQ ID NO: 82 and SEQ ID NO: 86, respectively, (f) SEQ ID NO: 90 and SEQ ID NO: 94, respectively, (g) SEQ ID NO: 98 and SEQ ID NO: 102, respectively, (h) SEQ ID NO: 106 and SEQ ID NO: 110, respectively, (i) SEQ ID NO: 114 and SEQ ID NO: 118, respectively, (j) SEQ ID NO: 122 and SEQ ID NO: 126, respectively, (k) SEQ ID NO: 130 and SEQ ID NO: 134, respectively, or (l) SEQ ID NO: 138 and SEQ ID NO: 142, respectively.

16. The fusion polypeptide of any one of claims 8-14, wherein the nanocage monomer is a ferritin monomer or subunit thereof.

17. The fusion polypeptide of claim 15, wherein the ferritin monomer or subunit thereof is a ferritin light chain or subunit thereof.

18. The fusion polypeptide of claim 15 or 16, wherein the ferritin monomer or subunit thereof is a human ferritin or subunit thereof.

19. The fusion polypeptide of any one of claims 15 to 18, wherein the ferritin monomer or subunit thereof is a ferritin monomer subunit.

20. The fusion polypeptide of any one of claims 8-19, wherein the HIV-1 antibody or an HIV-1-binding fragment thereof is a Fab fragment of an HIV-1 antibody.

21. The fusion polypeptide of claim 19, wherein the Fab fragment is a single chain Fab (scFab).

22. The fusion polypeptide of any one of claims 8-21, wherein the HIV-1 binding antibody or HIV-1 binding fragment thereof is linked to the nanocage monomer via an amino acid linker.

23. The fusion polypeptide of claim 22, wherein the amino acid linker comprises a (GnS)m linker.

24. The fusion polypeptide of claim 23, wherein the (GnS)m linker is a (GGGGS)m linker.

25. A self-assembled polypeptide complex comprising one or more fusion polypeptides, each fusion polypeptide being a fusion polypeptide of any one of claims 8-24.

26. A self-assembled polypeptide complex comprising (a) one or more first fusion polypeptides, each first fusion polypeptide comprising (1) a fragment of PDGM1400 linked to (2) a nanocage monomer or subunit thereof; (b) one or more second fusion polypeptides, each second fusion polypeptide comprising (1) a fragment of 10-1074 linked to (2) a nanocage monomer or subunit thereof; (c) one or more third fusion polypeptides, each third fusion polypeptide comprising (1) a fragment of N49P7 linked to (2) a nanocage monomer or subunit thereof; and (d) one or more fourth fusion polypeptides, each fourth fusion polypeptide comprising (1) an Fc polypeptide linked to (2) a nanocage monomer or subunit thereof.

27. A self-assembled polypeptide complex comprising (a) one or more first fusion polypeptides, each first fusion polypeptide comprising (1) a fragment of PDGM1400 linked to (2) a nanocage monomer or subunit thereof; (b) one or more second fusion polypeptides, each second fusion polypeptide comprising (1) a fragment of ePGT121 linked to (2) a nanocage monomer or subunit thereof; (c) one or more third fusion polypeptides, each third fusion polypeptide comprising (1) a fragment of N49P9.6FR linked to (2) a nanocage monomer or subunit thereof; and (d) one or more fourth fusion polypeptides, each fourth fusion polypeptide comprising (1) an Fc polypeptide linked to (2) a nanocage monomer or subunit thereof.

28. A self-assembled polypeptide complex comprising (a) one or more first fusion polypeptides, each first fusion polypeptide comprising (1) a fragment of PDGM1400 linked to (2) a nanocage monomer or subunit thereof;(b) one or more second fusion polypeptides, each second fusion polypeptide comprising (1) a fragment of ePGT121 linked to (2) a nanocage monomer or subunit thereof; (c) one or more third fusion polypeptides, each third fusion polypeptide comprising (1) a fragment of N49P7 linked to (2) a nanocage monomer or subunit thereof; and (d) one or more fourth fusion polypeptides, each fourth fusion polypeptide comprising (1) an Fc polypeptide linked to (2) a nanocage monomer or subunit thereof.

29. The self-assembled polypeptide complex of any one of claims 1-7 and 25-28, wherein the nanocage monomer is a ferritin monomer or subunit thereof.

30. The self-assembled polypeptide complex of claim 29, wherein the ferritin monomer or subunit thereof is a ferritin light chain or subunit thereof.

31. The self-assembled polypeptide complex of claim 30 or 31, wherein the ferritin monomer or subunit thereof is a human ferritin or subunit thereof.

32. The self-assembled polypeptide complex of any one of claims 29 to 31, wherein the ferritin monomer or subunit thereof is a ferritin monomer subunit.

33. The self-assembled polypeptide complex of any one of claims 29 to 32 , wherein the self-assembled polypeptide complex does not comprise any ferritin heavy chains or subunits of ferritin heavy chains.

34. The self-assembled polypeptide complex of any one of claims 1-7 and 25-32, wherein the HIV-1-binding moiety comprises an HIV-1 antibody or an HIV-1-binding fragment thereof.

35. The self-assembled polypeptide complex of claim 34, wherein the HIV-1-binding moiety is a Fab fragment of an HIV-1 antibody.

36. The self-assembled polypeptide complex of claim 35, wherein the HIV-1 antibody is a broadly neutralizing antibody.

37. The self-assembled polypeptide complex of claim 35 or 36, wherein the Fab fragment is a single chain Fab (scFab).

38. A pharmaceutical composition comprising the self-assembled polypeptide complex of any one of claims 1-7 and 25-37 and a pharmaceutically acceptable excipient.

39. A method for treating and / or preventing HIV-1 infection and / or an HIV-1-associated condition, the method comprising administering the self-assembled polypeptide complex ofany one of claims 1-7 or 25-37, or the pharmaceutical composition of claim 38, to a subject in need thereof.

40. The method of claim 39, wherein the subject is a mammal.

41. The method of claim 40, wherein the subject is a human.

42. The method of any one of claims 39 to 41, wherein the administering comprises systemic administration.

43. The method of claim 42, wherein the systemic administration comprises intranasal, intravascular, intramuscular, or subcutaneous administration.

44. Use of the self-assembled polypeptide complex of any one of claims 1-7, 25-37, or the pharmaceutical composition of claim 38, for treating and / or preventing HIV-1 infection and / or an HIV-1-associated condition.

45. The self-assembled polypeptide complex of any one of claims 1-7, 25-37, or the pharmaceutical composition of claim 38, for use in treating and / or preventing HIV-1 infection and / or an HIV-1-associated condition.

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