Anti-HIV-1 antibodies and uses thereof

Abstract

The instant disclosure provides antibodies and antigen-binding fragments thereof that can bind to HIV-1, e.g. CD4 binding site of HIV-1 env, and can neutralize HIV-1 infection. Also provided are polynucleotides that encode an antibody, vectors that comprise such polynucleotides, host cells that can express the antibodies, related compositions, and methods of using the herein disclosed compositions to, for example, treat or prevent an HIV-1 infection.

Description

[0001] ANTI-HIV-1 ANTIBODIES AND USES THEREOF

[0002] REFERENCE TO AN ELECTRONIC SEQUENCE LISTING

[0003] This application contains a Sequence Listing which has been submitted electronically in xml format and is hereby incorporated by reference in its entirety. Said xml copy, created on October 22, 2025, is named SeqList-368561-44802.xml and is 128,101 bytes in size.

[0004] BACKGROUND

[0005] Despite significant advances in treatment over decades, an estimated -39.9 million patients worldwide currently live with human immunodeficiency virus (HIV) infection, with only 77% of these patients accessing anti-retroviral treatments (WHO 2023 HIV statistics). Current anti-retroviral treatment regimens can suppress HIV levels in the blood to transform HIV infection from a fatal illness to a manageable long-term illness, but the virus is not eliminated. Anti-retroviral treatment regimens often require taking medication daily over a lifetime. Many patients prefer long-acting regimens, and studies show that long-acting regimens have increased patient adherence over daily therapy.

[0006] Thus, there is a need for more effective and practical modalities for treating HIV (e.g., HIV-1) infection.

[0007] BRIEF SUMMARY

[0008] Disclosed herein are antibodies or antigen-binding fragments thereof that are capable of binding to the CD4 binding site on the env protein of human immunodeficiency virus ty pe 1 (HIV-1). An antibody or antigen-binding fragment thereof according to the present disclosure comprises: (i) a heavy chain variable domain (VH) comprising a complementarity determining region (CDR)HL a CDRH2, and a CDRH3 comprising the amino acid sequences set forth in SEQ ID NOS:l-3, respectively; (ii) a light chain variable domain (VL) comprising a CDRL1 comprising the amino acid sequence of SEQ ID NO: 4, a CDRL2 comprising the amino acid sequence of Thr-Ala-His (TAH). and a CDRL3 comprising the amino acid sequence of SEQ ID NO:6 or SEQ ID NO: 121; and (iii) a Fc polypeptide or fragment thereof comprising substitution mutations, wherein the substitution mutations comprise: (a) G236A, Y300L, M428L and N434S; (b) M428L and N434S; (c) M252Y, S254T, and T256E; (d) G236A, Y300L, M252Y, S254T, and T256E; (e) G236A, A330L,

[0009] 1

[0010] 178476135.1 I332E, M428L, and N434S; or (f) G236A, A330L, I332E, M252Y, S254T, T256E; wherein the amino acid residues are numbered according to the EU numbering system.

[0011] In some embodiments, the antibody or antigen-binding fragment thereof of the present disclosure comprises a VH that comprises, consists essentially of, or consists of an amino acid sequence having at least 80%, 85%, 90%, 95%, 97%, or 99% identity7to the amino acid sequence set forth in SEQ ID NO:7, and / or a VL that comprises, consists essentially of, or consists of an amino acid sequence having at least 80%, 85%, 90%, 95%, 97%, or 99% identity to amino acid sequence set forth in SEQ ID NO: 8.

[0012] In some embodiments, the antibody or antigen-binding fragment thereof of the present disclosure comprises a VH that comprises, consists essentially of, or consists of the amino acid sequence set forth in SEQ ID NO: 7, and / or a VL that comprises or consists of the amino acid sequence set forth in SEQ ID NO: 8.

[0013] In some embodiments, the antibody or antigen-binding fragment thereof of the present disclosure comprises a Fc polypeptide or fragment thereof that comprises substitution mutations G236A, Y300L. M428L and N434S.

[0014] In some embodiments, the antibody or antigen-binding fragment thereof of the present disclosure comprises a Fc polypeptide or fragment thereof that comprises substitution mutations M428L and N434S.

[0015] In some embodiments, the antibody or antigen-binding fragment thereof of the present disclosure comprises a Fc polypeptide or fragment thereof that comprises substitution mutations M252Y, S254T, and T256E.

[0016] In some embodiments, the antibody or antigen-binding fragment thereof of the present disclosure comprises a Fc polypeptide or fragment thereof that comprises substitution mutations G236A, Y300L. M252Y, S254T, and T256E.

[0017] In some embodiments, the antibody or antigen-binding fragment thereof of the present disclosure comprises a CHI domain and / or a CL domain.

[0018] In some embodiments, the antibody or antigen-binding fragment thereof of the present disclosure comprises a CL domain that is a kappa CL domain.

[0019] In some embodiments, the antibody or antigen-binding fragment thereof of the present disclosure comprises a CHI domain that comprises the amino acid sequence set forth in SEQ ID NO: 119 and / or a CL domain that comprises the amino acid sequence set forth in SEQ ID NO: 117 or ll8.

[0020] 2

[0021] 178476135.1 In some embodiments, the antibody or antigen-binding fragment thereof of the present disclosure comprises an IgG isotype.

[0022] In some embodiments, the antibody or antigen-binding fragment thereof of the present disclosure comprises an IgGl, IgG2, IgG3, or IgG4 isotype.

[0023] In some embodiments, the antibody or antigen-binding fragment thereof of the present disclosure is a human antibody.

[0024] In some embodiments, the antibody or antigen-binding fragment thereof of the present disclosure comprises a monoclonal antibody.

[0025] In some embodiments, the antibody or antigen-binding fragment thereof of the present disclosure comprises a Glm3 allotype, a Glml7 allotype, a Glml allotype, or any combination thereof.

[0026] In some embodiments, the antibody or antigen-binding fragment thereof of the present disclosure comprises a Fc polypeptide that comprises, consists essentially of, or consists of the amino acid sequence having at least 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence set forth in any one of SEQ ID NOS: 76-79, 57, 64, 88-91. 100-103. and 112-115.

[0027] In some embodiments, the antibody or antigen-binding fragment thereof of the present disclosure comprises a Fc polypeptide that comprises, consists essentially of, or consists of the amino acid sequence set forth in any one of SEQ ID NOS: 76-79, 57, 64, 88-91, 100-103, and 112-115.

[0028] In some embodiments, the antibody or antigen-binding fragment thereof of the present disclosure comprises: (i) ahinge-CH2-CH3 polypeptide comprising the amino acid sequence set forth in any one of SEQ ID NOS: 72-75, 56, 63, 84-87, 96-99, and 108-111 ; or (ii) a CH1-CH3 polypeptide comprising the amino acid sequence set forth in any one of SEQ ID NOS: 43, 46-49, 52-55, 58-60, 62, 65, 66, 68-71, 80-83, 92-95, 104-107, and 120.

[0029] In some embodiments, the antibody or antigen-binding fragment thereof of the present disclosure comprises: (i) a heavy chain comprising an amino acid sequence having at least 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%. 96%. 97%. 98%. or 99% identity’ to the amino acid sequence set forth in SEQ ID NO:9; and / or (ii) a light chain comprising an amino acid sequence having at least 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence set forth in SEQ ID NO: 10.

[0030] In some embodiments, the antibody or antigen-binding fragment thereof of the present disclosure comprises: (i) a heavy chain comprising, consisting essentially of, or consisting of

[0031] 3

[0032] 178476135.1 the amino acid sequence set forth in SEQ ID NOV; and / or (ii) a light chain comprising, consisting essentially of. or consisting of the amino acid sequence set forth in SEQ ID NOTO.

[0033] In some embodiments, the antibody or antigen-binding fragment of the present disclosure is afucosylated; has been produced in a host cell that is incapable of fucosylation or that is inhibited in its ability to fucosylate a polypeptide; has been produced under conditions that inhibit fucosylation thereof by a host cell; or any combination thereof.

[0034] In some embodiments, the antibody of the present disclosure comprises a heavy chain (HC) and a light chain (LC), wherein the HC and the LC comprise the amino acid sequences set forth in SEQ ID NO: 9 and SEQ ID NO: 10, respectively, and wherein the antibody is afucosylated.

[0035] Also provided herein are pharmaceutical compositions comprising the antibodies or antigen-binding fragments disclosed herein, polynucleotides encoding the antibodies or antigen-binding fragments disclosed herein, vectors comprising the polynucleotides encoding the antibodies or antigen-binding fragments disclosed herein, host cells comprising the polynucleotides or vectors, kits, methods of making the antibodies or antigen-binding fragments disclosed herein, and methods of using the antibodies or antigen-binding fragments disclosed herein for treatment or prevention of HIV infection.

[0036] BRIEF DESCRIPTION OF THE DRAWINGS

[0037] FIGS. 1A-1D show breadth and potency of A06 antibody as compared to two clinical stage antibodies (N6 and 3BNC117) that also target the CD4 binding site of HIV- 1 env. FIG. 1A shows the neutralizing activity (ICso) of the antibodies against a panel of 12 global reference pseudo virus strains of HIV- 1 with different envelope amino acid sequences when tested in the TZM-bl cell pseudovirus neutralization assay. FIG. IB shows the neutralizing activity (IC50) of A06 antibody against a multiclade panel of 99 pseudoviruses with different HIV-1 envelope amino acid sequences when tested in the TZM-bl cell pseudovirus neutralization assay. FIG. 1C shows the neutralizing activity (IC50) of the A06 antibody against a multi clade panel of 100 clade C HIV-1 pseudoviruses (Clade C panel) with different HIV-1 envelope amino acid sequences when tested in the TZM-bl cell pseudovirus neutralization assay. FIG. ID shows the neutralizing activity (IC50) of A06 antibody against a panel of 185 pseudoviruses with different HIV-1 envelope amino acid sequences when tested in the TZM-bl cell pseudovirus neutralization assay; viral strains of this pseudovirus

[0038] 4

[0039] 178476135.1 panel were generated from virus sequences obtained from the Antibody Mediated Prevention Trials.

[0040] FIG. 2A shows neutralizing activity of A06 antibody against currently circulating viruses from multiple clades as compared with HIV-1 env CD4 binding site antibodies N6 and 3BNC117.

[0041] FIG. 2B shows neutralizing activity of A06 antibody against live viruses as compared with N6 and 3BNC117 antibodies.

[0042] FIG. 2C shows neutralization coverage (%) and potency (ICso) of A06 antibody against a panel of 50 donor-derived bulk outgrowth isolates. Neutralization data of reference broad neutralizing antibodies (bNAbs) against replication competent viruses were retrieved from Schommers, P. et al. Restriction of HIV-1 Escape by a Highly Broad and Potent Neutralizing 587 Antibody. Cell 180, 471-489.e22 (2020). Samples were tested in duplicates.

[0043] FIG. 3 shows a schematic for testing anti-viral effect for A06 antibody in a humanized immune sy stem (HlS)-mouse model (upper left); and HIV-1 RNA plasma copy numbers (top row of graphs) and their logic change (bottom row of graphs, compared to baseline (HIV-1 RNA plasma copy number of day -1)) in humanized NRG mice infected with HIV-1 vu2 (HIV-1 strain NL4-3 virus with envelope gene substituted for that of YU2); mice were treated subcutaneously with a 1 mg loading dose per antibody, followed by subcutaneous injections of 0.5 mg per antibody every 3-4 days (lo er right).

[0044] FIG. 4A shows that A06 antibody suppresses VRC01 escape virus in vivo. HIV-1 RNA plasma copy numbers (top) and their logio change (bottom, compared to baseline (HIV- 1 RNA plasma copy number of day -1)) in humanized mice infected with HIV-1YU2 (NL4-3 virus with envelope gene substituted for that of YU2). Mice were treated subcutaneously with a 1 mg loading dose per antibody, followed by subcutaneous injections of 0.5 mg per antibody every 3-4 days. Mice treated with the known CD4 binding site antibody VRC01 show a transient reduction of viremia, w hich returned to baseline levels in most mice within 2-4 w eeks. Following viral rebound after four w eeks of treatment, addition of A06 antibody (1 mg loading dose subcutaneous (s.c.) followed by 0.5 mg given s.c. every 3 days to 4 days) resulted in a sustained reduction of viremia in all (100%) of treated mice.

[0045] FIG. 4B shows neutralizing activity of A06 antibody, N6 antibody, and 3BNC117 antibody against a panel of pseudo viruses with different HIV-1 envelope amino acid sequences when tested in the TZM-bl cell pseudovirus neutralization assay; tested virus strains were selected from a reference pseudovirus panel that is known as "Resistant panel to

[0046] 5

[0047] 178476135.1 CD4bs bNAbs'’ and is described in Zhou et al., PLoS Pathog. 2019 Jun 13;15(6):el007819. doi: 10.1371 / joumal.ppat. l007819. PMID: 31194843; PMCID: PMC6592578 2017 Sep 12;91 (19): e00991 - 17; the pseudoviruses of this published reference panel display extraordinary resistance against CD4 binding site broad neutralizing antibodies (bNAbs).

[0048] FIG. 5 shows that Fc modifications to A06 antibody increase ADCC effector function (A06-LS-GAYL-Afuc = afucosylated A06 antibody with M428L / N434S and G236A / Y300L substitutions; A06-LS-GAALIE = A06 antibody with M428L / N434S and G236A / A330L / I332E substitutions; A06-LS-GRLR = A06 antibody with M428L / N434S and G236R / L328R substitutions). GRLR substitutions eliminate effector function, and A06-LS- BRLR antibody serves as a negative control.

[0049] FIG. 6A shows the in vitro neutralization profile of A06-LS (M428L / N434S) antibody vs. afucosylated A06 antibody with M428L / N434S and G236A / Y300L substitutions (A06-LS-GAYL-Afuc) against a global panel of pseudovirus (left) an AMP mini-panel of pseudovirus (center), and in vitro neutralization profile of A06 antibody vs. A06-LS-GAYL- Afuc against live HIV virus.

[0050] FIGS. 6B-6C show in vitro neutralization profile of A06-LS-GAYL-Afuc antibody against HIV patient isolates compared to reference clinical stage N6-LS-GAALIE antibody and 3BNC117 antibody (no Fc modification).

[0051] FIG. 6D shows in vitro binding of A06-LS-GAYL-Afuc antibody, A06-LS-GAALIE antibody. A06-LS antibody, and A06-LS-GRLR antibody to gpl20 determined by ELISA.

[0052] FIG. 7A shows schematic for in vitro testing of FcyR signaling. FIG. 7B shows FcyRIIIa-V, FcyRIIIa-F, and FcyRIIa-H signaling induced by A06-LS antibody, A06-LS- GAYL-Afuc antibody, A06-LS-GAALIE antibody and A06-LS-GRLR antibody. FIG. 7C shows FcyRIIIa-V signaling induced by A06-LS antibody, A06-LS-GAYL-Afuc antibody, A06-LS-GAALIE antibody and A06-LS-GRLR antibody. FIG. 7D shows A06-LS, A06-LS- GAALIE, A06-LS-GRLR, and A06-LS-GAYL-afuc binding affinity to human FcyRIIIa (CD 16a), FcyRIIa (CD32a), and FcyRIIb (CD32b).

[0053] FIG. 8A shows testing of ADCC function properties of A06 LS-GAYL-AFUC antibody, A06-LS-GAALIE antibody, A06-LS antibody, and A06-LS-GRLR antibody. FIG. 8B shows testing of A06 Fc modified antibodies with PBMCs as effector cells. FIG. 8C shows effector functions of phagocytosis, antigen presentation, and T cell activation of A06 Fc modified antibodies.

[0054] 6

[0055] 178476135.1 FIG. 9 shows effector function properties of A06 antibody and N49 antibody (also binds to CD4 binding site of HIV- 1 env) having wildtype Fc, GAYL-Afuc modified Fc, and GRLR modified Fc. The A06 antibodies tested also contain the “LS” mutation in the Fc region.

[0056] FIG. 10 shows PK of A06-rIgGlml7,l-LS antibody, A06-rIgGlml7,l-LS-GAYL- afuc antibody, and sotrovimab (anti-SARS-CoV- spike protein antibody).

[0057] FIG. 11 shows PK data in Tg32 SCID mice and predicted human PK. Tg32 SCID mice (n=5) received a single intravenous dose of 5 mg / kg A06+LS+GAYL-afuc mAb. Serum concentration of A06+LS+GAYL-afuc was measured for 63 days (left graph). Allometric scaling of Tg32 SCID mice PK data was used to predict human PK parameters clearance (CL), volume of distribution (V), and terminal elimination half-life (T1 / 2) (right graph).

[0058] FIGS. 12A-12B show simulated A06+LS+GAYL-afuc mAb PK for humans over 4 months (FIG. 12A) and 6 months (FIG. 12B). Allometric scaling of Tg32 PK (from FIG. 11) was used to predict human PK and inform dose predictions. Intravenous doses anticipated to cover serum concentrations of 2 pg / mL. 10 pg / mL, 20 pg / mL, and 40 pg / mL in 90% of population for 4 months and 6 months are shown in FIGS. 12A and 12B, respectively.

[0059] FIG. 13 shows schematic of in vitro live HIV suppression assay using primary human CD4+ T cells (upper) and in vitro effects of A06-LS-GAYL-afuc antibody or A06-LS-GRLR antibody on HIV infected CD4+ T cells.

[0060] FIG. 14 shows experimental schematic of in vivo suppression of HIV infection in a humanized mouse model and results as measured by HIV RNA levels.

[0061] FIG. 15 show s effect of effector function on viral suppression in mouse model of HIV infection.

[0062] DETAILED DESCRIPTION

[0063] Provided herein are antibodies and antigen-binding fragments thereof that can bind to and, in certain embodiments, can potentially neutralize infection by HIV, such as HIV-1. In certain embodiments, the antibodies and antigen-binding fragments thereof comprise a modified Fc polypeptide. Also provided are polynucleotides that encode the antibodies and antigen-binding fragments, vectors, host cells, and related compositions, as well as methods of using the antibodies, polynucleotides, vectors, host cells, and related compositions to treat (e.g., reduce, delay, eliminate) and / or to prevent and / or to diagnose an HIV-1 infection in a

[0064] 7

[0065] 178476135.1 subject and / or in the manufacture of a medicament for treating and / or preventing an HIV-1 infection in a subject.

[0066] Prior to setting forth this disclosure in more detail, it may be helpful to an understanding thereof to provide definitions of certain terms to be used herein. Additional definitions are set forth throughout this disclosure.

[0067] In the present description, any concentration range, percentage range, ratio range, or integer range is to be understood to include the value of any integer within the recited range and, when appropriate, fractions thereof (such as one tenth and one hundredth of an integer), unless otherwise indicated. Also, any number range recited herein relating to any physical feature, such as polymer subunits, size or thickness, are to be understood to include any integer within the recited range, unless otherwise indicated. As used herein, the term "about" means ± 20% of the indicated range, value, or structure, unless otherwise indicated. It should be understood that the terms "a" and "an" as used herein refer to "one or more" of the enumerated components. The use of the alternative (e.g., "or") should be understood to mean either one, both, or any combination thereof of the alternatives. As used herein, the terms "include," "have," and "comprise" are used synonymously, which terms and vanants thereof are intended to be construed as non-limiting.

[0068] "Optional" or "optionally" means that the subsequently described element, component, event, or circumstance may or may not occur, and that the description includes instances in which the element, component, event, or circumstance occurs and instances in which they do not.

[0069] In addition, it should be understood that the individual constructs, or groups of constructs, derived from the various combinations of the structures and subunits described herein, are disclosed by the present application to the same extent as if each construct or group of constructs was set forth individually. Thus, selection of particular structures or particular subunits is within the scope of the present disclosure.

[0070] The term "consisting essentially of' is not equivalent to "comprising" and refers to the specified materials or steps of a claim, or to those that do not materially affect the basic characteristics of a claimed subject matter. For example, a protein domain, region, or module (e.g., a binding domain) or a protein "consists essentially of' a particular amino acid sequence when the amino acid sequence of a domain, region, module, or protein includes extensions, deletions, mutations, or a combination thereof (e.g., amino acids at the amino- or carboxy -terminus or between domains) that, in combination, contribute to at most 20% (e.g..

[0071] 8

[0072] 178476135.1 at most 15%, 10%, 8%, 6%, 5%, 4%, 3%, 2% or 1%) of the length of a domain, region, module, or protein and do not substantially affect (i.e., do not reduce the activity by more than 50%, such as no more than 40%, 30%, 25%, 20%, 15%, 10%, 5%, or 1%) the activity of the domain(s), region(s), module(s), or protein (e.g., the target binding affinity of a binding protein).

[0073] As used herein, "amino acid" refers to naturally occurring and synthetic amino acids, as well as amino acid analogs and amino acid mimetics that function in a manner similar to the naturally occurring amino acids. Naturally occurring amino acids are those encoded by the genetic code, as well as those amino acids that are later modified, e.g. , hydroxyproline, y- carboxyglutamate, and O-phosphoserine. Amino acid analogs refer to compounds that have the same basic chemical structure as a naturally occurring amino acid, i.e., an a-carbon that is bound to a hydrogen, a carboxyl group, an amino group, and an R group, e.g., homoserine, norleucine, methionine sulfoxide, methionine methyl sulfonium. Such analogs have modified R groups (e.g., norleucine) or modified peptide backbones, but retain the same basic chemical structure as a naturally occurring amino acid. Amino acid mimetics refer to chemical compounds that have a structure that is different from the general chemical structure of an amino acid, but that functions in a manner similar to a naturally occurring amino acid.

[0074] As used herein, "mutation" refers to a change in the sequence of a nucleic acid molecule or polypeptide molecule as compared to a reference or wild-type nucleic acid molecule or polypeptide molecule, respectively. A mutation can result in several different ty pes of change in sequence, including substitution, insertion or deletion of nucleotide(s) or amino acid(s).

[0075] A "conservative substitution" refers to amino acid substitutions that do not significantly affect or alter binding characteristics of a particular protein. Generally, conservative substitutions are ones in which a substituted amino acid residue is replaced with an amino acid residue having a similar side chain. Conservative substitutions include a substitution found in one of the following groups: Group 1 : Alanine (Ala or A), Glycine (Gly or G), Serine (Ser or S), Threonine (Thr or T); Group 2: Aspartic acid (Asp or D), Glutamic acid (Glu or Z); Group 3: Asparagine (Asn or N), Glutamine (Gin or Q); Group 4: Arginine (Arg or R), Lysine (Lys or K), Histidine (His or H); Group 5: Isoleucine (He or I), Leucine (Leu or L), Methionine (Met or M), Valine (Vai or V); and Group 6: Phenylalanine (Phe or F), Tyrosine (Tyr or Y), Tryptophan (Trp or W). Additionally or alternatively, amino acids can be grouped into conservative substitution groups by similar function, chemical structure.

[0076] 9

[0077] 178476135.1 or composition (e.g., acidic, basic, aliphatic, aromatic, or sulfur-containing). For example, an aliphatic grouping may include, for purposes of substitution, Gly. Ala, Vai. Leu, and He. Other conservative substitutions groups include: sulfur-containing: Met and Cysteine (Cys or C); acidic: Asp, Glu, Asn, and Gin; small aliphatic, nonpolar or slightly polar residues: Ala, Ser, Thr, Pro, and Gly; polar, negatively charged residues and their amides: Asp, Asn, Glu, and Gin; polar, positively charged residues: His, Arg, and Lys; large aliphatic, nonpolar residues: Met, Leu, He, Vai, and Cys; and large aromatic residues: Phe, Tyr, and Trp. Additional information can be found in Creighton (1984) Proteins, W.H. Freeman and Company.

[0078] As used herein, "protein" or "polypeptide" refers to a polymer of amino acid residues. Proteins apply to naturally occurring amino acid polymers, as well as to amino acid polymers in which one or more amino acid residue is an artificial chemical mimetic of a corresponding naturally occurring amino acid, and non-naturally occurring amino acid polymers. Variants of proteins, peptides, and polypeptides of this disclosure are also contemplated. In certain embodiments, variant proteins, peptides, and polypeptides comprise or consist of an amino acid sequence that is at least 70%. 75%. 80%. 85%. 90%. 91%. 92%. 93%. 94%. 95%. 96%. 97%, 98%, 99%, or 99.9% identical to an amino acid sequence of a defined or reference amino acid sequence as described herein.

[0079] "Nucleic acid molecule" or "polynucleotide" or "polynucleic acid" refers to a polymeric compound including covalently linked nucleotides, which can be made up of natural subunits (e.g., purine or pyrimidine bases) or non-natural subunits (e g, morpholine ring). Purine bases include adenine, guanine, hypoxanthine, and xanthine, and pyrimidine bases include uracil, thymine, and cytosine. Nucleic acid molecules include polyribonucleic acid (RNA), which includes messenger RNA (mRNA), microRNA (miRNA), small interfering RNA (siRNA), viral genomic RNA, and synthetic RNA, and polydeoxyribonucleic acid (DNA), which includes complementary DNA (cDNA), genomic DNA (gDNA), and synthetic DNA, either of which may be single or double stranded. If single-stranded, the nucleic acid molecule may be the coding strand or non-coding (antisense) strand. A nucleic acid molecule encoding an amino acid sequence includes all nucleotide sequences that encode the same amino acid sequence. Some versions of the nucleotide sequences may also include intron(s) to the extent that the intron(s) would be removed through co- or post-transcriptional mechanisms. In other words, different

[0080] 10

[0081] 178476135.1 nucleotide sequences may encode the same amino acid sequence as the result of the redundancy or degeneracy of the genetic code, or by splicing.

[0082] Variants of nucleic acid molecules and polypeptides of this disclosure are also contemplated. Variant nucleic acid molecules are at least 70%, 75%, 80%, 85%, 90%, and are preferably 95%, 96%, 97%, 98%, 99%, or 99.9% identical to a nucleic acid molecule of a defined or reference polynucleotide as described herein, or that hybridize to a polynucleotide under stringent hybridization conditions of 0.015M sodium chloride, 0.0015M sodium citrate at about 65-68°C or 0.015M sodium chloride, 0.0015M sodium citrate, and 50% formamide at about 42°C. Nucleic acid molecule variants retain the capacity to encode a binding domain thereof having a functionality described herein, such as binding a target molecule. Variant polypeptides of this disclosure are at least 70%, 75%, 80%, 85%, 90%. and are preferably 95%, 96%, 97%, 98%, 99%, or 99.9% identical to a polypeptide of a defined or reference polypeptide as described herein.

[0083] “mRNA’' refers to any form of messenger RNA having a protein-coding region able to be translated in a host cell to produce the protein coded, in particular an antibody or antigen-binding fragment.

[0084] In some embodiments, each distinct mRNA may encode only one protein, such as a heavy chain (HC) or a VH-containing fragment thereof, or a light chain (LC) or a VL- containing fragment thereof. In such embodiments, a RNA therapeutic containing such mRNA may include at least two distinct mRNAs, one encoding a HC or a VH-containing fragment thereof, and the other encoding a LC or a VL-containing fragment thereof, so that, upon expression of the mRNAs in the cell, the resulting VH and VL proteins may combine to form an antigen-binding domain.

[0085] In other embodiments, all proteins, or at least a protein comprising a VH and a protein comprising a VL, may be encoded in a single mRNA. In some such embodiments, the VH- comprising protein and the VL-comprising protein may be expressed as separate proteins due to other regulatory elements within the coding sequence or encoded amino acid sequence, such as signal peptides, spacers, and translation-regulatory sequences, such as internal ribosome entry site (IRES) sequences. In some embodiments, a mRNA encodes a selfcleaving (e.g, 2A, such as a F2A, T2A, P2A, or E2A) peptide. A 2A peptide, optionally with a short linker or spacer sequence at the N- and / or C-terminal end, may be disposed between a VH-comprising protein and a VL-comprising protein. In certain embodiments, the order in

[0086] 11

[0087] 178476135.1 which the VH-comprising protein and VL-comprising protein and / or other expressed proteins occur in the mRNA may be optimized.

[0088] In some embodiments, the antibody or antigen-binding fragment may include a signal peptide that causes secretion of the antibody or antigen-binding fragment from the host cell. mRNA of the present disclosure may further contain one or more modified nucleosides. In particular embodiments, the modified nucleosides may stabilize the mRNA and reduce degradation of the mRNA in vitro, such as during production, storage, or after reconstitution and prior to administration of the mRNA, a vector comprising or consisting of the mRNA, an mRNA therapeutic construct, or a composition containing any of the preceding. In particular embodiments, the modified nucleosides may stabilize and reduce degradation of the mRNA in vivo, such as in the skin, muscle, blood, interstitial fluid, other extracellular environment, or intracellular environment after administration of the mRNA, a vector or construct containing the mRNA, an mRNA therapeutic construct, or a composition containing any of the preceding. In particular embodiments, the modified nucleosides may reduce or avoid a cellular immune response to the mRNA. In particular embodiments, the modified nucleosides may enhance amplification of the mRNA in the host cell and / or expression of a protein or peptide encoded by the mRNA. Modified nucleosides may include pseudouridine, such as N1 -methylpseudouridine, 5 -methylcytidine, 2-thiouridine, N6-methyladenonsine.

[0089] "Percent sequence identity" refers to a relationship between two or more sequences, as determined by comparing the sequences. Preferred methods to determine sequence identity are designed to give the best match between the sequences being compared. For example, the sequences are aligned for optimal comparison purposes (e.g., gaps can be introduced in one or both of a first and a second amino acid or nucleic acid sequence for optimal alignment). Further, non-homologous sequences may be disregarded for comparison purposes. The percent sequence identity' referenced herein is calculated over the length of the reference sequence, unless indicated otherwise. Methods to determine sequence identity and similarity can be found in publicly available computer programs. Sequence alignments and percent identity calculations may be performed using a BLAST program (e.g., BLAST 2.0, BLASTP, BLASTN, or BLASTX). The mathematical algorithm used in the BLAST programs can be found in Altschul et al.. Nucleic Acids Res. 25:3389-3402, 1997. Within the context of this disclosure, it will be understood that where sequence analysis software is used for analysis, the results of the analysis are based on the "default values" of the program

[0090] 12

[0091] 178476135.1 referenced. "Default values" mean any set of values or parameters which originally load with the software when first initialized.

[0092] The term "isolated" means that the material is removed from its original environment (e.g. , the natural environment if it is naturally occurring). For example, a naturally occurring nucleic acid or polypeptide present in a living animal is not isolated, but the same nucleic acid or polypeptide, separated from some or all of the co-existing materials in the natural system, is isolated. Such nucleic acid could be part of a vector and / or such nucleic acid or polypeptide could be part of a composition (e.g, a cell lysate), and still be isolated in that such vector or composition is not part of the natural environment for the nucleic acid or polypeptide.

[0093] The term "gene" means the segment of DNA or RNA involved in producing a polypeptide chain; in certain contexts, it includes regions preceding and following the coding region (e.g., 5’ untranslated region (UTR) and 3’ UTR) as well as intervening sequences (introns) between individual coding segments (exons).

[0094] A "functional variant" refers to a polypeptide or polynucleotide that is structurally similar or substantially structurally similar to a parent or reference compound of this disclosure, but differs slightly in composition (e.g., one base, atom or functional group is different, added, or removed), such that the polypeptide or encoded polypeptide is capable of performing at least one function of the parent polypeptide with at least 50% efficiency, preferably at least 55%, 60%, 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99%, 99.9%, or 100% level of activity of the parent polypeptide. Tn other words, a functional variant of a polypeptide or encoded polypeptide of this disclosure has "similar binding," "similar affinity " or "similar activity" when the functional variant displays no more than a 50% reduction in performance in a selected assay as compared to the parent or reference polypeptide, such as an assay for measuring binding affinity (e.g., Biacore® or tetramer staining measuring an association (Ka) or a dissociation (KD) constant).

[0095] As used herein, a "functional portion" or "functional fragment" refers to a polypeptide or polynucleotide that comprises only a domain, portion or fragment of a parent or reference compound, and the polypeptide or encoded polypeptide retains at least 50% activity associated with the domain, portion or fragment of the parent or reference compound, preferably at least 55%, 60%, 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99%, 99.9%, or 100% level of activity of the parent polypeptide, or provides a biological benefit (e.g., effector function). A "functional portion" or "functional fragment" of a polypeptide or

[0096] 13

[0097] 178476135.1 encoded polypeptide of this disclosure has "similar binding" or "similar activity " when the functional portion or fragment displays no more than a 50% reduction in performance in a selected assay as compared to the parent or reference polypeptide (preferably no more than 20% or 10%, or no more than a log difference as compared to the parent or reference with regard to affinity).

[0098] As used herein, the term "engineered," "recombinant," or "non-natural" refers to an organism, microorganism, cell, nucleic acid molecule, or vector, that includes at least one genetic alteration or has been modified by introduction of an exogenous or heterologous nucleic acid molecule, wherein such alterations or modifications are introduced by genetic engineering (z.e., human intervention). Genetic alterations include, for example, modifications introducing expressible nucleic acid molecules encoding functional RNA, proteins, fusion proteins or enzymes, or other nucleic acid molecule additions, deletions, substitutions, or other functional disruption of a cell’s genetic material. Additional modifications include, for example, non-coding regulator}' regions in which the modifications alter expression of a polynucleotide, gene, or operon.

[0099] As used herein, "heterologous" or "non-endogenous" or "exogenous" refers to any gene, protein, compound, nucleic acid molecule, or activity that is not native to a host cell or a subj ect, or any gene, protein, compound, nucleic acid molecule, or activity' native to a host cell or a subject that has been altered. Heterologous, non-endogenous, or exogenous includes genes, proteins, compounds, or nucleic acid molecules that have been mutated or otherwise altered such that the structure, activity, or both is different as between the native and altered genes, proteins, compounds, or nucleic acid molecules. In certain embodiments, heterologous, non-endogenous, or exogenous genes, proteins, or nucleic acid molecules (e.g., receptors, ligands, etc.) may not be endogenous to a host cell or a subject, but instead nucleic acids encoding such genes, proteins, or nucleic acid molecules may have been added to a host cell by conjugation, transformation, transfection, electroporation, or the like, wherein the added nucleic acid molecule may integrate into a host cell genome or can exist as extra- chromosomal genetic material (e.g., as a plasmid or other self-replicating vector). The term "homologous" or "homolog" refers to a gene, protein, compound, nucleic acid molecule, or activity found in or derived from a host cell, species, or strain. For example, a heterologous or exogenous polynucleotide or gene encoding a polypeptide may be homologous to a native polynucleotide or gene and encode a homologous polypeptide or activity, but the polynucleotide or polypeptide may’ have an altered structure, sequence, expression level, or

[0100] 14

[0101] 178476135.1 any combination thereof. A non-endogenous polynucleotide or gene, as well as the encoded polypeptide or activity, may be from the same species, a different species, or a combination thereof.

[0102] In certain embodiments, a nucleic acid molecule or portion thereof native to a host cell will be considered heterologous to the host cell if it has been altered or mutated, or a nucleic acid molecule native to a host cell may be considered heterologous if it has been altered with a heterologous expression control sequence or has been altered with an endogenous expression control sequence not normally associated with the nucleic acid molecule native to a host cell. In addition, the term "heterologous" can refer to a biological activity that is different, altered, or not endogenous to a host cell. As described herein, more than one heterologous nucleic acid molecule can be introduced into a host cell as separate nucleic acid molecules, as a plurality of individually controlled genes, as a polycistronic nucleic acid molecule, as a single nucleic acid molecule encoding a fusion protein, or any combination thereof.

[0103] As used herein, the term "endogenous" or "native" refers to a polynucleotide, gene, protein, compound, molecule, or activity that is normally present in a host cell or a subject.

[0104] The term "expression", as used herein, refers to the process by which a polypeptide is produced based on the encoding sequence of a nucleic acid molecule, such as a gene. The process may include transcription, post-transcriptional control, post-transcriptional modification, translation, post-translational control, post-translational modification, or any combination thereof. An expressed nucleic acid molecule is typically operably linked to an expression control sequence (e.g., a promoter).

[0105] The term "operably linked" refers to the association of two or more nucleic acid molecules on a single nucleic acid fragment so that the function of one is affected by the other. For example, a promoter is operably linked with a coding sequence when it is capable of affecting the expression of that coding sequence (i.e., the coding sequence is under the transcriptional control of the promoter). "Unlinked" means that the associated genetic elements are not closely associated with one another and the function of one does not affect the other.

[0106] As described herein, more than one heterologous nucleic acid molecule can be introduced into a host cell as separate nucleic acid molecules, as a plurality of individually controlled genes, as a polycistronic nucleic acid molecule, as a single nucleic acid molecule encoding a protein (e.g. , a heavy chain of an antibody), or any combination thereof. When

[0107] 15

[0108] 178476135.1 two or more heterologous nucleic acid molecules are introduced into a host cell, it is understood that the two or more heterologous nucleic acid molecules can be introduced as a single nucleic acid molecule (e.g., on a single vector), on separate vectors, integrated into the host chromosome at a single site or multiple sites, or any combination thereof. The number of referenced heterologous nucleic acid molecules or protein activities refers to the number of encoding nucleic acid molecules or the number of protein activities, not the number of separate nucleic acid molecules introduced into a host cell.

[0109] The term "construct" refers to any polynucleotide that contains a recombinant nucleic acid molecule (or, when the context clearly indicates, a fusion protein of the present disclosure). A (polynucleotide) construct may be present in a vector (e g., a bacterial vector, a viral vector) or may be integrated into a genome. A "vector" is a nucleic acid molecule that is capable of transporting another nucleic acid molecule. Vectors may be, for example, plasmids, cosmids, viruses, an RNA vector or a linear or circular DNA or RNA molecule that may include chromosomal, non-chromosomal, semi-synthetic or synthetic nucleic acid molecules. Vectors of the present disclosure also include transposon systems (e.g., Sleeping Beauty, see, e.g.. Geurts et al.. Mol. Ther. 8: 108, 2003: Mates et al., Nat. Genet. 4T.15 , 2009). Exemplary vectors are those capable of autonomous replication (episomal vector), capable of delivering a polynucleotide to a cell genome (e.g., viral vector), or capable of expressing nucleic acid molecules to which they are linked (expression vectors).

[0110] As used herein, "expression vector" or "vector" refers to a DNA or RNA construct containing a nucleic acid molecule that is operably linked to a suitable control sequence capable of effecting the expression of the nucleic acid molecule in a suitable host. Such control sequences include a promoter to effect transcription, an optional operator sequence to control such transcription, a sequence encoding suitable mRNA ribosome binding sites, and sequences which control termination of transcription and translation. The vector may be a plasmid, a phage particle, a virus, or simply a potential genomic insert. Once transformed into a suitable host, the vector may replicate and function independently of the host genome, or may, in some instances, integrate into the genome itself or deliver the polynucleotide contained in the vector into the genome without the vector sequence. In the present specification, "plasmid," "expression plasmid," "virus," and "vector" are often used interchangeably. In some embodiments, the “vector” may comprise or consist of mRNA.

[0111] The term "introduced" in the context of inserting a nucleic acid molecule into a cell, means "transfection", "transformation." or "transduction" and includes reference to the

[0112] 16

[0113] 178476135.1 incorporation of a nucleic acid molecule into a eukaryotic or prokaryotic cell wherein the nucleic acid molecule may be incorporated into the genome of a cell (e.g, chromosome, plasmid, plastid, or mitochondrial DNA), converted into an autonomous replicon, or transiently expressed (e.g., transfected mRNA).

[0114] In certain embodiments, polynucleotides of the present disclosure may be operatively linked to certain elements of a vector. For example, polynucleotide sequences that are needed to affect the expression and processing of coding sequences to which they are ligated may be operatively linked. Expression control sequences may include appropriate transcription initiation, termination, promoter, and enhancer sequences; efficient RNA processing signals such as splicing and polyadenylation signals; sequences that stabilize cytoplasmic mRNA; sequences that enhance translation efficiency (z.e., Kozak consensus sequences); sequences that enhance protein stability; and possibly sequences that enhance protein secretion. Expression control sequences may be operatively linked if they are contiguous with the gene of interest and expression control sequences that act in trans or at a distance to control the gene of interest.

[0115] In certain embodiments, the vector comprises a plasmid vector or a viral vector (e.g., a lentiviral vector or a y-retro viral vector). Viral vectors include retrovirus, adenovirus, parvovirus (e.g, adeno-associated viruses), coronavirus, negative strand RNA viruses such as ortho-myxovirus (e.g, influenza virus), rhabdovirus (e.g. rabies and vesicular stomatitis virus), paramyxovirus (e.g, measles and Sendai), positive strand RNA viruses such as picomavirus and alphavirus, and double-stranded DNA viruses including adenovirus, herpesvirus (e.g., Herpes Simplex virus types 1 and 2, Epstein-Barr virus, cytomegalovirus), and poxvirus (e.g, vaccinia, fowlpox, and canarypox). Other viruses include, for example, Norwalk virus, togavirus, flavivirus. reoviruses. papovavirus, hepadnavirus, and hepatitis virus. Examples of retroviruses include avian leukosis-sarcoma, mammalian C-type, B-type viruses, D type viruses, HTLV-BLV group, lenti virus, spumavirus (Coffin, J. M., Retroviridae: The viruses and their replication, In Fundamental Virology, Third Edition, B. N. Fields et al.. Eds.. Lippincott-Raven Publishers, Philadelphia, 1996).

[0116] "Retroviruses" are viruses having an RNA genome, which is reverse-transcribed into DNA using a reverse transcriptase enzyme, the reverse-transcribed DNA is then incorporated into the host cell genome. "Gammaretrovirus" refers to a genus of the retroviridae family. Examples of gammaretroviruses include mouse stem cell virus, murine leukemia virus, feline leukemia virus, feline sarcoma virus, and avian reticuloendotheliosis viruses.

[0117] 17

[0118] 178476135.1 "Lentiviral vectors" include HIV-based lentiviral vectors for gene delivery7, which can be integrative or non-integrative, have relatively large packaging capacity7, and can transduce a range of different cell types. Lentiviral vectors are usually generated following transient transfection of three (packaging, envelope, and transfer) or more plasmids into producer cells. Like HIV, lentiviral vectors enter the target cell through the interaction of viral surface glycoproteins with receptors on the cell surface. On entry7, the viral RNA undergoes reverse transcription, which is mediated by the viral reverse transcriptase complex. The product of reverse transcription is a double-stranded linear viral DNA, which is the substrate for viral integration into the DNA of infected cells.

[0119] In certain embodiments, the viral vector can be a gammaretrovirus, e.g., Moloney murine leukemia virus (MLV)-derived vectors. In other embodiments, the viral vector can be a more complex retrovirus-derived vector, e.g., a lentivirus-derived vector. HIV- 1 -derived vectors belong to this category7. Other examples include lentivirus vectors derived from HIV- 2, FIV, equine infectious anemia virus, SIV, and Maedi-Visna virus (ovine lentivirus). Methods of using retroviral and lentiviral viral vectors and packaging cells for transducing mammalian host cells with viral particles containing transgenes are known in the art and have been previous described, for example, in: U.S. Patent 8,119,772; Walchli et al., PLoS One 6327930, 2011; Zhao et al., J. Immunol. 174:4415, 2005; Engels et al., Hum. Gene Ther. 14: 1155, 2003; Frecha et al.. Mol. Ther. 18: 1748, 2010; and Verhoeyen et al., Methods Mol. Biol. 506:97, 2009. Retroviral and lentiviral vector constructs and expression systems are also commercially available. Other viral vectors also can be used for polynucleotide delivery including DNA viral vectors, including, for Example adenovirus-based vectors and adeno- associated virus (AAV)-based vectors; vectors derived from herpes simplex viruses (HSVs), including amplicon vectors, replication-defective HSV and attenuated HSV (Krisky et al., Gene Ther. 5: 1517, 1998).

[0120] Other vectors that can be used with the compositions and methods of this disclosure include those derived from baculoviruses and a- viruses. (Jolly, D J. 1999. Emerging Viral Vectors, pp 209-40 in Friedmann T. ed. The Development of Human Gene Therapy. New York: Cold Spring Harbor Lab), or plasmid vectors (such as sleeping beauty or other transposon vectors).

[0121] When a viral vector genome comprises a plurality7of polynucleotides to be expressed in a host cell as separate transcripts, the viral vector may also comprise additional sequences between the two (or more) transcripts allowing for bicistronic or multicistronic expression.

[0122] 18

[0123] 178476135.1 Examples of such sequences used in viral vectors include internal ribosome entry sites (IRES), furin cleavage sites, viral 2A peptide, or any combination thereof.

[0124] Plasmid vectors, including DNA-based antibody or antigen-binding fragmentencoding plasmid vectors for direct administration to a subject, are described further herein.

[0125] As used herein, a “carrier” or “vehicle” can refer to a molecule able to introduce a polynucleotide into a host cell. In specific embodiments, the carrier may comprise a lipid, a lipid-derived delivery vehicle, such as a liposome, a solid lipid nanoparticle, an oily suspension, a submicron lipid emulsion, a lipid microbubble, an inverse lipid micelle, a cochlear liposome, a lipid microtubule, a lipid microcylinder, a lipid nanoparticle (LNP), a lipopolyplex (LPP), a cationic polypeptide, a polymeric nanoparticle, or a nanoscale platform, such as a nanoemulsion, (see. e.g., Li et al. Wilery Interdiscip Rev. Nanomed Nanobiotechnol. 11 (2): el 530 (2019), incorporated by reference herein with respect to its description of carriers and vehicles and methods of making and using such carriers and vehicles to form therapeutics).

[0126] Principles, reagents, and techniques for designing appropriate mRNA and formulating mRNA-LNP and delivering the same are described in, for example. Pardi et al. (J Control Release 217345-351 (2015)); Thess et al. (Mol Ther 23: 1456-1464 (2015)); Thran et al. (EMBO Mol Med 9(10):1434-1448 (2017); Kose et al. (Sci. Immunol. 4 eaaw6647 (2019); and Sabnis et al. (Mol. Ther. 26: 1509-1519 (2018)). which techniques, including capping, codon optimization, nucleoside modification, purification of mRNA, incorporation of the mRNA into stable lipid nanoparticles (e g., ionizable cationic lipid / phosphatidylcholine / cholesterol / PEG-lipid; ionizable lipid: distearoyl PC:cholesterol:polyethylene glycol lipid), and subcutaneous, intramuscular, intradermal, intravenous, intraperitoneal, and intratracheal administration of the same, are incorporated herein by reference.

[0127] In some embodiments, LNPs may be formed from a cationic lipid, in particular an ionizable lipid. In other embodiments, LNPs may be formed from lipidoids, which are molecules derived from ionizable lipids and dendrimers. LNPs, in some embodiments, may further include structural lipids, such as a phospholipid, cholesterol, or both. In some embodiments, the LNPs may comprise i) an ionizable lipid having a positive charge able to bind to the negatively charged RNA backbone, ii) a PEGylated lipid, iii) a cholesterol, and iv) a phospholipid.

[0128] 19

[0129] 178476135.1 As used herein, the term "host" refers to a cell or microorganism targeted for genetic modification with a heterologous nucleic acid molecule to produce a polypeptide of interest (e.g., an antibody of the present disclosure).

[0130] A host cell may include any individual cell or cell culture which may receive a vector or the incorporation of nucleic acids or express proteins. The term also encompasses progeny of the host cell, whether genetically or phenotypically the same or different. Suitable host cells may depend on the vector and may include mammalian cells, animal cells, human cells, simian cells, insect cells, yeast cells, and bacterial cells. These cells may be induced to incorporate the vector or other material by use of a viral vector, transformation via calcium phosphate precipitation, DEAE-dextran, electroporation, microinjection, or other methods. See, for example, Sambrook et al.. Molecular Cloning: A Laboratory Manual 2d ed. (Cold Spring Harbor Laboratory, 1989).

[0131] In the context of an HIV-1 infection, a "host" refers to a cell or a subject infected with HIV-1.

[0132] "Antigen" or "Ag". as used herein, refers to an immunogenic molecule that provokes an immune response. This immune response may involve antibody production, activation of specific immunologically-competent cells, activation of complement, antibody dependent cytotoxicity or any combination thereof. An antigen (immunogenic molecule) may be, for example, a peptide, glycopeptide, polypeptide, glycopolypeptide, polynucleotide, polysaccharide, lipid, or the like. It is readily apparent that an antigen can be synthesized, produced recombinantly, or derived from a biological sample. Exemplary biological samples that can contain one or more antigens include tissue samples, stool samples, cells, biological fluids, or combinations thereof. Antigens can be produced by cells that have been modified or genetically engineered to express an antigen. Antigens can also be expressed or presented on the surface of a cell infected by HIV-1. In certain embodiments, the antigen targeted by the antibodies of the present disclosure is HIV-1 envelope glycoprotein (env). In certain embodiments, the antigen targeted by the antibodies of the present disclosure is the CD4 binding site (CD4bs) within the gp!20 envelope protein of HIV- 1.

[0133] Human immunodeficiency virus 1 (HIV-1) refers to the most common type of HIV. HIV-1 is a single-stranded, positive-sense, enveloped RNA retrovirus that can cause AIDS, a chronic disease leading to immunodeficiency and susceptibility to opportunistic infections.

[0134] The term "epitope" or "antigenic epitope" includes any molecule, structure, amino acid sequence, or protein determinant that is recognized and specifically bound by a cognate

[0135] 20

[0136] 178476135.1 binding molecule, such as an immunoglobulin, or other binding molecule, domain, or protein. Epitopic determinants generally contain chemically active surface groupings of molecules, such as amino acids or sugar side chains, and can have specific three-dimensional structural characteristics, as well as specific charge characteristics. Where an antigen is or comprises a peptide or protein, the epitope can be comprised of consecutive amino acids (e.g., a linear epitope), or can be comprised of amino acids from different parts or regions of the protein that are brought into proximity by protein folding (e.g., a discontinuous or conformational epitope), or non-contiguous amino acids that are in close proximity irrespective of protein folding.

[0137] Antibodies, Antigen-Binding Fragments, and Compositions

[0138] In one aspect, the present disclosure provides an isolated antibody, or an antigenbinding fragment, that is capable of binding to an env protein from HIV-1 and / or neutralizing HIV-1 in a human subject, in particular the CD4 binding site of the HIV-1 gpl20 envelope glycoprotein (‘“env”). The antigen can be referred to as an env or HIV-1 env antigen, and the antibody or antigen-binding fragment as an “anti-env” or ”anti-HIV-l env” antibody or antigen-binding fragment. Any antibody or antigen-binding fragment of the present disclosure (including a multispecific antibody or antigen-binding fragment) can be described as an “anti-env” antibody or antigen-binding fragment, and / or as an “anti-env antigen” antibody or antigen-binding fragment. The antibodies or antigen-binding fragments of the present disclosure comprise a Fc polypeptide comprising specific substitution mutations as described herein.

[0139] In certain embodiments, an antibody or antigen-binding fragment of the present disclosure binds to env on the surface of an HIV-1 viral particle or env on the surface of an infected cell.

[0140] In certain embodiments, an antibody or antigen-binding fragment of the present disclosure is capable of neutralizing infection by HIV-1. As used herein, a "neutralizing antibody" is one that can neutralize, i.e., prevent, inhibit, reduce, impede, or interfere with, the ability of a pathogen to initiate and / or perpetuate an infection in a host. The terms "neutralizing antibody" and "an antibody that neutralizes" or "antibodies that neutralize" are used interchangeably herein. In any of the presently disclosed embodiments, the antibody or antigen-binding fragment is capable of preventing and / or neutralizing an HIV-1 infection in an m vitro model of infection, in an in vivo animal model of infection and / or in a human.

[0141] 21

[0142] 178476135.1 In certain embodiments, the antibody, or antigen-binding fragment thereof, is human, humanized, or chimeric.

[0143] Antibodies and antigen-binding fragments of the present disclosure include "chimeric antibodies" in which a portion of the heavy and / or light chain is identical with or homologous to corresponding sequences in antibodies derived from a particular species or belonging to a particular antibody class or subclass, while the remainder of the chain(s) is identical with or homologous to corresponding sequences in antibodies derived from another species or belonging to another antibody class or subclass, as well as fragments of such antibodies, so long as they exhibit the desired biological activity (see, U.S. Pat. Nos. 4,816,567; 5,530,101 and 7,498,415; and Morrison et al., Proc. Natl. Acad. Sci. USA, 57:6851-6855 (1984)). For example, chimeric antibodies may comprise human and non-human residues. Furthermore, chimeric antibodies may comprise residues that are not found in the recipient antibody or in the donor antibody. These modifications are made to further refine antibody performance. For further details, see Jones et al., Nature 321 :522-525 (1986); Riechmann et al., Nature 332:323-329 (1988); and Presta, Curr. Op. Struct. Biol. 2:593-596 (1992). Chimeric antibodies also include primatized and humanized antibodies.

[0144] A "humanized antibody" is generally considered to be a human antibody that has one or more amino acid residues introduced into it from a source that is non-human. These non- human amino acid residues are typically taken from a variable domain. Humanization may be performed following the method of Winter and co-workers (Jones et al.. Nature, 321:522- 525 (1986): Reichmann et al., Nature, 332323-321 (1988); Verhoeyen et al., Science, 239: 1534-1536 (1988)), by substituting non-human variable sequences for the corresponding sequences of a human antibody. Accordingly, such "humanized" antibodies are chimeric antibodies (U.S. Pat. Nos. 4,816,567; 5,530.101 and 7,498,415) wherein substantially less than an intact human variable domain has been substituted by the corresponding sequence from a non-human species. In some instances, a "humanized" antibody is one which is produced by a non-human cell or animal and comprises human sequences, e.g., CH domains.

[0145] A "human antibody" is an antibody containing only sequences that are present in an antibody that is produced by a human (i.e., sequences that are encoded by human antibodyencoding genes). However, as used herein, human antibodies may comprise residues or modifications not found in a naturally occurring human antibody (e.g., an antibody that is isolated from a human), including those modifications and variant sequences described herein. These are typically made to further refine or enhance antibody performance. In some

[0146] 22

[0147] 178476135.1 instances, human antibodies are produced by transgenic animals. For example, see U.S. Pat. Nos. 5,770,429; 6,596.541 and 7,049,426.

[0148] As used herein, "specifically binds" refers to an association or union of an antibody or antigen-binding fragment to an antigen with an affinity or Ka (i.e., an equilibrium association constant of a particular binding interaction with units of 1 / M) equal to or greater than 105M'1(which equals the ratio of the on-rate [Kon] to the off rate [Koff] for this association reaction), while not significantly associating or uniting with any other molecules or components in a sample. Alternatively, affinity may be defined as an equilibrium dissociation constant (Ka) of a particular binding interaction with units of M (e.g., 10'5M to ICT13M). Antibodies may be classified as "high-affinity" antibodies or as "low-affinity" antibodies. "High- affinity" antibodies refer to those antibodies having a Ka of at least 109M1, at least IO10M1, at least 1011M1, at least 1012M-1, or at least 1013M'1. "Low-affinity" antibodies refer to those antibodies having a Ka of up to 108M-1, up to 107M’1, up to 106M’1, up to 10’ M'1. Alternatively, affinity' may be defined as an equilibrium dissociation constant (Kd) of a particular binding interaction with units of M (e.g., 10’5M to 10’13M).

[0149] In some embodiments, various pharmacokinetic ("PK") parameters are used to describe or characterize the antibodies or antigen-binding fragments provided herein. Details regarding collection of antibody serum concentrations for purpose of evaluating PK parameters are described in association with the Examples herein. The term "ti / 2" or "halflife" refers to the elimination half-life of the antibody included in the pharmaceutical composition administered to a subject. The term "Clast" generally refers to the last measurable plasma concentration (z. e. , subsequent thereto, the substance is not present at a measurable concentration in plasma).

[0150] A variety of assays are known for identifying antibodies of the present disclosure that bind a particular target, as well as determining binding domain or binding protein affinities, such as Western blot, ELISA (e.g., direct, indirect, or sandwich), analytical ultracentrifugation, spectroscopy, and surface plasmon resonance (Biacore®) analysis (see, e.g., Scatchard et al.. Ann. N. Y. Acad. Set. 57:660, 1949; Wilson, Science 295:2103, 2002; Wolff et al., Cancer Res. 53:2560. 1993; and U.S. Patent Nos. 5,283.173. 5,468,614. or the equivalent). Assays for assessing affinity or apparent affinity or relative affinity are also known.

[0151] In certain examples, binding can be determined by recombinantly expressing an env antigen in a host cell (e.g, by transfection) and immunostaining the (e.g. fixed, or fixed and

[0152] 23

[0153] 178476135.1 permeabilized) host cell with antibody and analyzing binding by flow cytometry (e.g., using a ZE5 Cell Analyzer (BioRad®) and Flow Jo software (TreeStar). In some embodiments, positive binding can be defined by differential staining by antibody of env-expressing cells versus control (e.g., mock) cells.

[0154] In some embodiments an antibody or antigen-binding fragment of the present disclosure binds to env, as measured using biolayer interferometry, or by surface plasmon resonance.

[0155] In some embodiments an antibody or antigen-binding fragment of the present disclosure may be assessed for competitive binding against another antibody or antigenbinding fragment in using surface plasmon resonance.

[0156] Certain characteristics of presently disclosed antibodies or antigen-binding fragments may be described using IC50 or EC50 values. In certain embodiments, the IC50 is the concentration of a composition (e.g., antibody) that results in half-maximal inhibition of the indicated biological or biochemical function, activity, or response. In certain embodiments, the EC50 is the concentration of a composition that provides the half-maximal response in the assay. In some embodiments, e.g., for describing the ability of a presently disclosed antibody or antigen-binding fragment to neutralize infection by HIV-1, IC50 and ECso are used interchangeably.

[0157] Terms understood by those in the art of antibody technology- are each given the meaning acquired in the art, unless expressly defined differently herein. For example, the term "antibody" refers to an intact antibody comprising at least two heavy (H) chains and two light (L) chains inter-connected by disulfide bonds, as well as any antigen-binding portion or fragment of an intact antibody that has or retains the ability to bind to the antigen target molecule recognized by the intact antibody, such as an scFv, Fab. or Fab'2 fragment. Thus, the term "antibody" herein includes polyclonal and monoclonal antibodies, including intact antibodies and functional (antigen-binding) antibody fragments that include a Fc polypeptide. The term encompasses genetically engineered and / or otherwise modified forms of immunoglobulins, such as chimeric antibodies, fully human antibodies, humanized antibodies, heteroconjugate antibodies, and multispecific, e.g., bispecific antibodies. Unless otherwise stated, the term "antibody" should be understood to encompass functional antibody fragments. The term also encompasses intact or full-length antibodies, including antibodies of any class or sub-class, including IgG and sub-classes thereof (IgGl, IgG2, IgG3, IgG4), IgM, IgE, IgA. and IgD.

[0158] 24

[0159] 178476135.1 The terms "VL" or "VL" and "VH" or "VH" refer to the variable binding region from an antibody light chain and an antibody heavy chain, respectively. In certain embodiments, a VL is a kappa (K) class (also "VK" herein). In certain embodiments, a VL is a lambda (X) class. The variable binding regions comprise discrete, well-defined sub-regions known as "complementarity determining regions" (CDRs) and "framework regions" (FRs). The terms "complementarity determining region." and "CDR," are synonymous with "hypervariable region" or "HVR," and refer to sequences of amino acids within antibody variable regions, which, in general, together confer the antigen specificity and / or binding affinity of the antibody, wherein consecutive CDRs (i.e., CDR1 and CDR2, CDR2 and CDR3) are separated from one another in primary structure by a framework region. There are three CDRs in each variable region (CDRH1, CDRH2, CDRH3; CDRL1, CDRL2. CDRL3; also referred to as CDRHs and CDRLs, respectively). In certain embodiments, an antibody VH comprises four FRs and three CDRs as follows: FR1-CDRH1-FR2-CDRH2-FR3-CDRH3- FR4; and an antibody VL comprises four FRs and three CDRs as follows: FR1-CDRL1-FR2- CDRL2-FR3-CDRL3-FR4. In general, the VH and the VL together form the antigen-binding site through their respective CDRs. In certain embodiments, one or more CDRs do not contact antigen and / or do not contribute energetically to antigen binding.

[0160] As used herein, a "variant" of a CDR refers to a functional variant of a CDR sequence having up to 1-3 amino acid substitutions (e g., conservative or non-conservative substitutions), deletions, or combinations thereof.

[0161] Numbering of CDR and framework regions may be according to any known method or scheme, such as the Kabat, Chothia, EU, IMGT, Contact, North, Martin, AbM, and AHo numbering schemes (see, e.g., Kabat et al., "Sequences of Proteins of Immunological Interest, U.S. Dept. Health and Human Services, Public Health Service National Institutes of Health, 1991, 5th ed.; Chothia and Lesk, J. Mol. Biol. 196:901-917 (1987)); Lefranc et al., Dev. Comp. Immunol. 27:55, 2003; Honegger and Pluckthun, J. Mol. Bio. 309:657-670 (2001); North et al. J Mol Biol. (2011) 406:228-56; doi: 10. 1016 / j.jmb.2010. 10.030; Abhinandan and Martin. Mol Immunol. (2008) 45:3832-9. 10. 1016 / j.molimm.2008.05.022). The antibody and CDR numbering systems of these references are incorporated herein by reference. Equivalent residue positions can be annotated and for different molecules to be compared using Antigen receptor Numbering And Receptor Classification (ANARCI) software tool (2016, Bioinformatics 15:298-300). Accordingly, identification of CDRs of an exemplary variable domain (VH or VL) sequence as provided herein according to one numbering

[0162] 25

[0163] 178476135.1 scheme is not exclusive of an antibody comprising CDRs of the same variable domain as determined using a different numbering scheme.

[0164] In certain embodiments, the antibody or antigen binding fragment is an anti-env antibody or antigen-binding fragment as set forth in Table 1 or Table 2.

[0165] Table 1 summarizes IMGT CDR amino acid sequences and variable heavy and light chain amino acid sequences (SEQ ID NOs.) of certain antibodies of the present disclosure. Table 2 summarizes heavy chain and light chain amino acid sequences, variable heavy chain and variable light chain amino acid sequences, and heavy chain constant region and light chain constant region amino acid sequences (SEQ ID NOs.) of certain antibodies of the present disclosure.

[0166] TABLE 1. CDR (IMGT) and variable light and heavy chain amino acid sequences (SEQ

[0167] ID NOs.) of certain antibodies

[0168] TABLE 2. Variable heavy and light chain amino acid sequences and heavy and light chain amino acid sequences (SEQ ID NOs) of certain antibodies.

[0169] 26

[0170] 178476135.1

[0171] 27

[0172] 178476135.1

[0173] 28

[0174] 178476135.1

[0175] 29

[0176] 178476135.1

[0177] In certain embodiments, the antibody or antigen-binding fragment comprises a CDRH1, a CDRH2, a CDRH3, a CDRL1, a CDRL2, and a CDRL3, wherein the CDRH1, CDRH2, CDRH3, CDRL1, CDRL2. and CDRL3 comprise, consist essentially of, or consist of the amino acid sequences set forth in: (i) SEQ ID NOS: 1 -6, respectively; (ii) SEQ ID NOS: 1-5 and 121, respectively; (iii) SEQ ID NOS: 11-16, respectively; (iv) SEQ ID NOS 19, 2. 3, and 4, 20, 21, respectively; (v) SEQ ID NOS: 24-26 and 14-16, respectively; or (vi) SEQ ID NOS: 11, 29, 30, and 14-16, respectively.

[0178] In certain embodiments, the antibody or antigen-binding fragment comprises a CDRH1, a CDRH2, a CDRH3, a CDRL1, a CDRL2, and a CDRL3, wherein the CDRH1,

[0179] 30

[0180] 178476135.1 CDRH2, CDRH3, CDRL1, CDRL2, and CDRL3 comprise, consist essentially of, or consist of the amino acid sequences set forth in SEQ ID NOS: 1-6, respectively.

[0181] In certain embodiments, the antibody or antigen-binding fragment comprises a CDRH1, a CDRH2, a CDRH3, a CDRL1, a CDRL2, and a CDRL3, wherein the CDRH1, CDRH2, CDRH3, CDRL1, CDRL2, and CDRL3 comprise, consist essentially of, or consist of the amino acid sequences set forth in SEQ ID NOS: 1-5 and 121, respectively.

[0182] In certain embodiments, the antibody or antigen-binding fragment comprises a CDRH1, a CDRH2, a CDRH3, a CDRL1, a CDRL2, and a CDRL3, wherein the CDRH1, CDRH2, CDRH3, CDRL1, CDRL2, and CDRL3 comprise, consist essentially of, or consist of the amino acid sequences set forth in SEQ ID NOS: 11-16, respectively.

[0183] In certain embodiments, the antibody or antigen-binding fragment comprises a CDRH1, a CDRH2, a CDRH3, a CDRL1, a CDRL2, and a CDRL3, wherein the CDRH1, CDRH2, CDRH3, CDRL1, CDRL2, and CDRL3 comprise, consist essentially of, or consist of the amino acid sequences set forth in SEQ ID NOS: 19, 2, 3, and 4, 20, 21, respectively.

[0184] In certain embodiments, the antibody or antigen-binding fragment comprises a CDRH1, a CDRH2, a CDRH3, a CDRL1. a CDRL2, and a CDRL3, wherein the CDRH1, CDRH2, CDRH3, CDRL1, CDRL2, and CDRL3 comprise, consist essentially of, or consist of the amino acid sequences set forth in SEQ ID NOS: 24-26 and 14-16, respectively.

[0185] In certain embodiments, the antibody or antigen-binding fragment comprises a CDRH1, a CDRH2, a CDRH3, a CDRL1. a CDRL2, and a CDRL3, wherein the CDRH1, CDRH2, CDRH3, CDRL1 , CDRL2, and CDRL3 comprise, consist essentially of, or consist of the amino acid sequences set forth in SEQ ID NOS: 11, 29, 30, and 14-16, respectively.

[0186] In some embodiments, an antibody or antigen-binding fragment comprises a CDRH1, a CDRH2, a CDRH3, a CDRL1. a CDRL2, and / or a CDRL3. or functional variants thereof (and in certain embodiments, comprises a CDRH1, a CDRH2, a CDRH3, a CDRLL a CDRL2, and a CDRL3, or functional variants thereof) of the VH and VL amino acid sequences set forth in: (i) SEQ ID NOs.: 7 and 8, respectively; (ii) SEQ ID NOS: 17 and 18, respectively; (iii) SEQ ID NOS: 22 and 23, respectively; (iv) SEQ ID NOS: 27 and 28. respectively; or (v) SEQ ID NOS: 31 and 32, respectively.

[0187] In some embodiments, the antibody or antigen-binding fragment comprises a CDRH1, a CDRH2, a CDRH3, a CDRL1, a CDRL2, and / or a CDRL3, or functional variants thereof, of the VH and VL amino acid sequences set forth in SEQ ID NOS: 7 and 8, respectively.

[0188] 31

[0189] 178476135.1 In some embodiments, the antibody or antigen-binding fragment comprises a CDRH1, a CDRH2, a CDRH3, a CDRL1. a CDRL2, and / or a CDRL3. or functional variants thereof, of the VH and VL amino acid sequences set forth in SEQ ID NOS: 17 and 18, respectively.

[0190] In some embodiments, the antibody or antigen-binding fragment comprises a CDRH1, a CDRH2, a CDRH3, a CDRL1, a CDRL2, and / or a CDRL3, or functional variants thereof, of the VH and VL amino acid sequences set forth in SEQ ID NOS: 22 and 23, respectively.

[0191] In some embodiments, the antibody or antigen-binding fragment comprises a CDRH1, a CDRH2, a CDRH3, a CDRL1, a CDRL2, and / or a CDRL3, or functional variants thereof, of the VH and VL amino acid sequences set forth in SEQ ID NOS: 27 and 28, respectively.

[0192] In some embodiments, the antibody or antigen-binding fragment comprises a CDRH1, a CDRH2, a CDRH3, a CDRLL a CDRL2, and / or a CDRL3. or functional variants thereof, of the VH and VL amino acid sequences set forth in SEQ ID NOS: 31 and 32, respectively.

[0193] In some embodiments, the antibody or antigen-binding fragment comprises a variable heavy domain (VH) and a variable light domain (VL), wherein the VH and the VL comprise, consist essentially of, or consist of, amino acid sequences having at least 75%, at least 80%, at least 85%, 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% identity or similarity to, or comprising or consisting essentially of, or consisting of, the VH and VL amino acid sequences set forth in: (i) SEQ ID NOs.: 7 and 8, respectively; (ii) SEQ ID NOS: 17 and 18, respectively; (iii) SEQ ID NOS: 22 and 23, respectively; (iv) SEQ ID NOS: 27 and 28. respectively; or (v) SEQ ID NOS: 31 and 32, respectively.

[0194] In some embodiments, the antibody or antigen-binding fragment comprises a VH and VL comprising, consisting essentially of, or consisting of amino acid sequences having at least 75%, at least 80%, at least 85%, 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% identity or similarity to, or comprising, consisting essentially of, or consisting of, the VH and VL amino acid sequences set forth in SEQ ID NOS: 7 and 8, respectively.

[0195] In some embodiments, the antibody or antigen-binding fragment comprises a VH and VL comprising, consisting essentially of, or consisting of amino acid sequences having at least 75%, at least 80%, at least 85%, 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% identity or similarity to, or comprising, consisting essentially of, or consisting of, the VH and VL amino acid sequences set forth in SEQ ID NOS: 17 and 18, respectively.

[0196] 32

[0197] 178476135.1 In some embodiments, the antibody or antigen-binding fragment comprises a VH and VL comprising, consisting essentially of, or consist of, amino acid sequences having at least 75%, at least 80%, at least 85%, 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% identity or similarity to, or comprising, consisting essentially of, or consisting of, the VH and VL amino acid sequences set forth in SEQ ID NOS: 22 and 23, respectively.

[0198] In some embodiments, the antibody or antigen-binding fragment comprises a VH and VL comprising, consisting essentially of, or consisting of amino acid sequences having at least 75%, at least 80%, at least 85%, 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% identity or similarity to, or comprising, consisting essentially of, or consisting of, the VH and VL amino acid sequences set forth in SEQ ID NOS: 27 and 28, respectively.

[0199] In some embodiments, the antibody or antigen-binding fragment comprises a VH and VL comprising, consisting essentially of, or consisting of amino acid sequences having at least 75%, at least 80%, at least 85%, 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% identity or similarity to, or comprising, consisting essentially of, or consisting of, the VH and VL amino acid sequences set forth in SEQ ID NOS: 31 and 32, respectively.

[0200] In certain embodiments, an antibody or an antigen-binding fragment of the present disclosure comprises a VH and a VL of any one of the antibodies shown in Tables 1 and 2.

[0201] In some embodiments, the antibody or antigen-binding fragment comprises a heavy chain (HC) and a light chain (LC), wherein the HC and the LC comprise, consist essentially of, or consist of, amino acid sequences having at least 75%, at least 80%, at least 85%, 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% identity or similarity to, or comprising, consisting essentially of, or consisting of, the HC and LC amino acid sequences set forth in SEQ ID NOS: 9 and 10, respectively.

[0202] In some embodiments, the antibody, or antigen-binding fragment thereof comprises a heavy chain comprising, consisting essentially of, or consisting of the amino acid sequence set forth in SEQ ID NO:9; and / or a light chain comprising, consisting essentially of, or consisting of the amino acid sequence set forth in SEQ ID NO: 10.

[0203] In some embodiments, the antibody or antigen-binding fragment comprises a heavy chain (HC) and a light chain (LC) wherein: (i) the HC comprises a VH that comprises.

[0204] 33

[0205] 178476135.1 consists essentially of, or consists of, an amino acid sequence having at least 75%, at least 80%, at least 85%, 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% identity or similarity to, or comprising, consisting essentially of, or consisting of the amino acid sequence of a VH selected from Table 2, and a heavy chain constant region (CH) that comprises, consists essentially of, or consists of, an amino acid sequence having at least 75%, at least 80%, at least 85%, 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% identity or similarity to, or comprising, consisting essentially of, or consisting of the amino acid sequence of the corresponding CH from Table 2; and (ii) the LC comprises a VL that comprises, consists essentially of, or consists of. an amino acid sequence having at least 75%, at least 80%, at least 85%, 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% identity or similarity to, or comprising, consisting essentially of, or consisting of the amino acid sequence of the corresponding VL selected from Table 2, and a light chain constant region (CL) that comprises, consists essentially of, or consists of, an amino acid sequence having at least 75%, at least 80%, at least 85%, 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% identity or similarity' to, or comprising, consisting essentially of, or consisting of the amino acid sequence of a corresponding CL selected from Table 2

[0206] Additional examples of heavy chain and light chain sequences for exemplary antibodies or antigen-binding fragments of the present disclosure, and combinations of VH, VL, CH, and CL sequences making up the heavy and light chains of exemplary' antibodies or antigen-binding fragments of the present disclosure are provided in Tables 2 and 4.

[0207] In certain embodiments, an antibody or an antigen-binding fragment of the present disclosure comprises a VH, a VL, a CH, and a CL selected from Table 4.

[0208] The term “CL” refers to an “immunoglobulin light chain constant region” or a “light chain constant region,” i.e., a constant region from an antibody light chain. The term “CH” refers to an “immunoglobulin heavy chain constant region” or a “heavy chain constant region,” which is further divisible, depending on the antibody isotype, into CHI, CH2, and CH3 (IgA, IgD, IgG), or CHI, CH2, CH3, and CH4 domains (IgE, IgM). The Fc region of an antibody heavy chain is described further herein.

[0209] 34

[0210] 178476135.1 In any of the presently disclosed embodiments, an antibody or antigen-binding fragment of the present disclosure comprises any one or more of CL, a CHI, a CH2, and a CH3. In certain embodiments, a CL comprises an amino acid sequence having 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%, at least 99%, or 100% identity (or similarity) to the amino acid sequence of a human IgG kappa constant domain (e.g., to SEQ ID NO: 117) or to a human IgG lambda constant domain (e.g., to SEQ ID NO: 118). In certain embodiments, a CHl-hinge-CH2-CH3 (also referred to as “CH1-CH3”) comprises an amino acid sequence having 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%, at least 99%, or 100% identity (or similarity) to the amino acid sequence of a human IgGl isotype, an engineered human IgGl isotvpe. a human IgG3 isotype, or an engineered human IgG3 isotype. In certain embodiments, a CHl-hinge-CH2-CH3 (also referred to herein as “CH 1 -CH3”) comprises an amino acid sequence having 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%, at least 99%, or 100% identity (or similarity) to the amino acid sequence of any one of SEQ ID NOs.:43. 46-49, 52-55, 58-60. 62. 65. 66, 68-71, 80-83. 92-95, 104-107, and 120.

[0211] It will be understood that, for example, production in a mammalian cell line can remove one or more C-terminal lysine residues of an antibody heavy chain (see, e.g.. Liu et al. mAbs 6(5): 1145-1154 (2014)). Accordingly, an antibody or antigen-binding fragment of the present disclosure can comprise a heavy chain, a CHI -CH3, a CH3, or an Fc polypeptide wherein a C-terminal lysine residue is present or is absent; in other words, encompassed are embodiments where the C-terminal residue of a heavy chain, a CH1-CH3, or an Fc polypeptide is not a lysine, and embodiments where a lysine is the C-terminal residue. In certain embodiments, a composition comprises a plurality of an antibody and / or an antigenbinding fragment of the present disclosure, wherein one or more antibody or anti gen -binding fragment does not comprise a lysine residue at the C-terminal end of the heavy chain, CH1- CH3, or Fc polypeptide, and wherein one or more antibody or antigen-binding fragment comprises a lysine residue at the C-terminal end of the heavy chain, CH1-CH3, or Fc polypeptide. In some embodiments, an antibody or antigen-binding fragment of the present disclosure can comprise a heavy chain, a CH1-CH3, a CH3, or an Fc polypeptide wherein a C-terminal lysine is present or absent (e.g., the last amino acid of any one of SEQ ID NOS.: 43-60, 62-66, 68-115, and 120).

[0212] 35

[0213] 178476135.1 In some embodiments, an antibody or antigen-binding fragment of the present disclosure can comprise a heavy chain, a CH1-CH3, a CH3, or an Fc polypeptide wherein a C-terminal glycine-lysine (GK) sequence (e.g., the last two amino acids of any one of SEQ ID NOS.: 43-60, 62-66, 68-115, and 120) is present or is absent.

[0214] In some embodiments, an antibody or antigen-binding fragment of the present disclosure can comprise a heavy chain, a CH1-CH3, a CH3, or an Fc polypeptide wherein a C-terminal glycine-lysine (GK) sequence (e.g., the last two amino acids of any one of SEQ ID NOS.: 43-60, 62-66, 68-115, and 120) is substituted with the amino acids glutamic acid- leucine (EL).

[0215] For each embodiment of the antibodies, antigen-binding fragment, and compositions above, in parallel embodiments, a combination of two or more antibodies or antigen-binding fragments thereof of the present disclosure, either as separate antibodies in a single composition, or in a bi specific antibody, may have the same HIV-1 env binding, neutralizing, infection preventing and / or treating, and other recited properties.

[0216] For each embodiment of the antibodies, antigen-binding fragment, and compositions above, in parallel embodiments, a combination of two or more antibodies or antigen-binding fragments thereof, wherein the first antibody is an antibody of the present disclosure.

[0217] In some embodiments, within the combination of two or more antibodies, antigenbinding fragment, and compositions, the first antibody or antigen-fragment thereof comprises a CDRH1, a CDRH2, a CDRH3, a CDRL1. a CDRL2, and a CDRL3, wherein the CDRH1, CDRH2, CDRH3, CDRL1 , CDRL2, and CDRL3 comprise, consist essentially of, or consist of the amino acid sequences set forth in SEQ ID NOS: 1-6, respectively.

[0218] In some embodiments, within the combination of two or more antibodies, antigenbinding fragment, and compositions, the first antibody or antigen-binding fragment comprises a CDRH1, a CDRH2, a CDRH3, a CDRL1, a CDRL2, and a CDRL3, wherein the CDRH1, CDRH2, CDRH3, CDRL1, CDRL2, and CDRL3 comprise, consist essentially of, or consist of the amino acid sequences set forth in SEQ ID NOS: 1-5 and 121, respectively.

[0219] In some embodiments, within the combination of two or more antibodies, antigenbinding fragment, and compositions, the first antibody or antigen-binding fragment comprises a VH and a VL comprising, consisting essentially of, or consisting of the amino acid sequences set forth in SEQ ID NOS: 7 and 8, respectively.

[0220] In some embodiments, within the combination of two or more antibodies, antigenbinding fragment, and compositions, the first antibody or antigen-binding fragment comprises

[0221] 36

[0222] 178476135.1 a heavy chain and a light chain comprising, consisting essentially of, or consisting of the amino acid sequences set forth in SEQ ID NOS: 9 and 10, respectively.

[0223] Antibodies and antigen binding fragments may be constructed in various formats. Exemplar}^ antibody formats disclosed in Spiess et al., Mol. Immunol. 67(2):95 (2015), and in Brinkmann and Kontermann, mAbs 9(2):282-212 (2017), which formats and methods of making the same are incorporated herein by reference and include, for example, Knobs-Into- Holes (KIH) assemblies, KIH Common Light-Chain antibodies, tetravalent HCabs, CrossMabs, Dual Action Fabs (DAFs) (two-in-one or four-in-one), DutaMabs, DT-IgG, Charge Pairs, Fab-arm Exchange, SEEDbodies, Triomabs, LUZ-Y assemblies, Fcabs, KZ- bodies, orthogonal Fabs, DVD-Igs (e.g, US Patent No. 8,258,268, which formats are incorporated herein by reference in their entirety). IgG(H)-scFv, scFv-(H)IgG, IgG(L)-scFv. scFv-(L)IgG, IgG(L,H)-Fv, IgG(H)-V, V(H)-IgG, IgG(L)-V, V(L)-IgG, KIH IgG-scFab, 2scFv-IgG, IgG-2scFv, scFv4-Ig, Zybody, and DVI-IgG (four-in-one), as well as so-called FIT-Ig (e.g., PCT Publication No. WO 2015 / 103072, which formats are incorporated herein by reference in their entirety), so-called WuxiBody formats (e.g, PCT Publication No. WO 2019 / 057122, which formats are incorporated herein by reference in their entirety), and so- called In-Elbow-Insert Ig formats (lEI-Ig; e.g., PCT Publication Nos. WO 2019 / 024979 and WO 2019 / 025391, which formats are incorporated herein by reference in their entirety).

[0224] In certain embodiments, an antibody or antigen-binding fragment of the present disclosure is monospecific (e.g.. binds to a single epitope) or is multispecific (e.g., binds to multiple epitopes and / or target molecules).

[0225] Monospecific or multispecific antibodies or antigen-binding fragments of the present disclosure can comprise any combination of the VH and VL sequences and / or any combination of the CDRH1, CDRH2, CDRH3, CDRL1, CDRL2. and CDRL3 sequences disclosed herein. A bispecific or multispecific antibody or antigen-binding fragment may, in some embodiments, comprise one, two, or more antigen-binding domains (e.g., a VH and a VL) of the instant disclosure. Two or more binding domains may be present that bind to the same or a different antigen epitope, and a bispecific or multispecific antibody or antigenbinding fragment as provided herein can, in some embodiments, comprise a further antigenspecific binding domain, and / or can comprise a binding domain that binds to a different antigen or pathogen altogether.

[0226] Monospecific or multispecific antibodies or antigen-binding fragments of the present disclosure constructed comprise as a first VH and a first VL having any combination of the

[0227] 37

[0228] 178476135.1 VH and VL sequences and / or any combination of the CDRH1, CDRH2, CDRH3, CDRL1, CDRL2, and CDRL3 sequences disclosed herein in Table 1 or Table 2, respectively; and a second VH and a second VL having any combination of the VH and VL sequences and / or any combination of the CDRH1, CDRH2, CDRH3, CDRL1, CDRL2, and CDRL3 sequences disclosed herein in in Table 1 or Table 2, respectively. The first VH and the first VL together form a first antigen-binding site, and wherein the second VH and the second VL together form a second antigen-binding site.

[0229] An antibody or antigen-binding fragment may be of any allotype or combination of allotypes. “Allotype” refers to the allelic variation found among the IgG subclasses. For example, an allotype may comprise Glml (or Glm(a)), Glm2 (or Glm(x)), Glm3 (or Glm(f)), Glml7 (or Gm(z))m), Glm27, and / or Glm28. Glm27 and Glm28 have been described as “alloallotypes”.

[0230] The Glm3 and Glml7 allotypes are located at the same position in the CHI domain (position 214 according to EU numbering). Glm3 comprises R214 (EU), while Glml7 comprises K214 (EU). The Glml allotype is located in the CH3 domain (at positions 356 and 358 (EU)) and refers to the replacements E356D and M358L. The Glm2 allotype refers to a replacement of the alanine in position 431 (EU) by a glycine. Glm allotypes, alloallotypes, and features thereof are known in the art and described at, for example, www.imgt.org / IMGTrepertoire / Proteins / allotypes / human / IGH / IGHC / Glm_allotypes.html and Lefranc, M.-P. and Lefranc, G. Human Gm. Km and Am allotypes and their molecular characterization: a remarkable demonstration of polymorphism In: B. Tait, F. Christiansen (Eds.), Immunogenetics, chap. 34, Humana Press, Springer, New York, USA. Methods Mol. Biol. 2012; 882, 635-680. PMID: 22665258, LIGM: 406, the contents and allotypes and allotype information of which are incorporated herein by reference.

[0231] The Glml allotype may be combined, for example, with the Glm3, Glml7, Glm27, Glm2, and / or Glm28 allotype. In some embodiments, an allotype is GIm3 with no Glml (GIm3,-l). In some embodiments, an allotype is Glml 7,1 allotype. In some embodiments, an allotype is Glm3,l. In some embodiments, an allotype is Glml7 with no Glml (Glml7,-1). Optionally, these allotypes may be combined (or not combined) with the Glm2, Glm27 or GIm28 allotype. For example, an allotype may be Glml7,l,2.

[0232] In some embodiments, an antibody or antigen-binding fragment of the present disclosure comprises a Glm3 allotype or a Glm3.1 allotype. In some embodiments, an antibody or antigen-binding fragment of the present disclosure comprises a Glml 7,1

[0233] 38

[0234] 178476135.1 allotype. In some embodiments, the antibody of Glm3, Glm3,l, or the Glml7,l allotype further comprises one, two, three, four, five, or more mutations that modify binding to an Fc receptor (FcR). In some embodiments, a mutation improves half-life of the polypeptide by enhancing binding to a human FcRn. In some embodiments, a mutation can improve effector function by altered binding to a human FcyR. Examples of Glm3, Glm3,l, or the Glml7,l allotype Fc polypeptides and heavy chain constant regions that can be used in the antibodies or antigen binding fragments of the present disclosure are provided in Table 4.

[0235] In certain embodiments, the antibody or antigen-binding fragment comprises a Fc polypeptide, or a fragment thereof. The "Fc", also referred to as Fc region, Fc moiety, or Fc polypeptide, comprises the carboxy-terminal portions (i.e., the CH2 and CH3 domains of IgG) of both antibody H chains held together by disulfides. A Fc may comprise a dimer comprised of two Fc polypeptides (i.e., two CH2-CH3 polypeptides). Antibody "effector functions" refer to those biological activities attributable to the Fc region (a native sequence Fc region or amino acid sequence variant Fc region) of an antibody, and vary with the antibody isotype. Examples of antibody effector functions include: Clq binding and complement dependent cytotoxicity; Fc receptor binding; antibody-dependent cell-mediated cytotoxicity (ADCC); phagocytosis; down regulation of cell surface receptors (e.g., B cell receptor); and B cell activation. As discussed herein, modifications (e.g., amino acid substitutions) may be made to a Fc polypeptide in order to modify (e.g., improve, reduce, or ablate) one or more functionality of a Fc-containing polypeptide (e.g., an antibody of the present disclosure). Such functions include, for example, Fc receptor (FcR) binding, antibody half-life modulation (e.g., by binding to FcRn), ADCC function, protein A binding, protein G binding, and complement binding.

[0236] Presently disclosed polypeptides include those that comprise a variant of: an IgG Fc polypeptide or a fragment thereof, wherein the variant comprises one or more modifications as compared to the IgG Fc polypeptide or fragment thereof. It will be understood that, unless stated otherwise, a “reference’' polypeptide or antibody (e.g., reference IgG Fc polypeptide or fragment thereof, reference antibody, reference CH2 polypeptide, reference IgG hinge-CH2, reference IgG hinge-Fc polypeptide, reference CH3 polypeptide) is preferably identical to the recited molecule (e.g., variant of an Fc polypeptide or fragment thereof; polypeptide comprising such a variant; antibody comprising a variant of an Fc polypeptide) except for the recited difference or differences.

[0237] In any of the presently disclosed embodiments, the antibody or antigen-binding

[0238] 39

[0239] 178476135.1 fragment comprises a Fc polypeptide or a fragment thereof, including a CH2 (or a fragment thereof), a CH3 (or a fragment thereof), or a CH2 and a CH3. wherein the CH2, the CH3, or both can be of any isotype (e.g., IgGl, IgG2, IgG3, IgG4, IgA, IgE, or IgM isotype) and may contain amino acid substitutions or other modifications as compared to a corresponding wildtype CH2 or CH3, respectively. In certain embodiments, a Fc of the present disclosure comprises two CH2-CH3 polypeptides that associate to form a dimer. Examples of CH2- CH3 polypeptides are provided in Table 4, including SEQ ID NOS: 45, 51, 57. 64, 76-79, 88- 91, 100-103, and 112-115.

[0240] In certain embodiments, the antibody or antigen-binding fragment of the present disclosure comprises a hinge-CH2-CH3 polypeptide. The hinge-CH2-CH3 polypeptide may be of any isotype (e.g.. IgGl, IgG2, IgG3. IgG4, IgA. IgE, or IgM isotype) and may contain amino acid substitutions or other modifications as compared to a corresponding wild-type hinge, CH2, or CH3, respectively. Examples of hinge-CH2-CH3 polypeptides are provided in Table 4, including SEQ ID NOS: 44, 50, 56, 63, 72-75, 84-87, 96-99, and 108-111.

[0241] In certain embodiments, the Fc polypeptide or fragment thereof may comprise or consist of at least a portion of an Fc polypeptide or fragment thereof that is involved in FcRn binding. In certain embodiments, the Fc polypeptide or fragment thereof comprises one or more amino acid modifications that improve binding affinity for (e.g., enhance binding to) FcRn (e.g., at a pH of about 6.0) and, in some embodiments, thereby extend in vivo half-life of a molecule comprising the Fc polypeptide or fragment thereof (e.g., as compared to a reference Fc polypeptide or fragment thereof or antibody that is otherw ise the same but does not comprise the modification(s)). In certain embodiments, the Fc polypeptide or fragment thereof comprises or is derived from an IgG Fc and a half-life-extending mutation comprises any one or more of: M428L; N434S; M252Y; S254T; T256E (EU numbering). In certain embodiments, the Fc polypeptide or fragment thereof comprises or is derived from an IgGl Fc and a half-life-extending mutation comprises any one or more of: M428L; N434S; M252Y; S254T; T256E (EU numbering).

[0242] In certain embodiments, the Fc polypeptide or fragment thereof comprises a half-life- extending mutation comprising M428L / N434S substitutions (EU numbering, also referred to herein as "MLNS", "LS", "_LS", and "-LS"). In particular, an antibody having LS mutations may comprise an amino acid sequence set forth in any of SEQ ID NOs: 55-60, 68-79, and 92- 103.

[0243] 40

[0244] 178476135.1 In certain embodiments, the Fc polypeptide or fragment thereof comprises a half-life- extending mutation comprises M252Y / S254T / T256E substitutions (EU numbering, also referred to as “YTE”). In particular, an antibody having YTE mutations may comprise an amino acid sequence set forth in any of SEQ ID NOs: 61-67, 80-91, 104-115, and 120.

[0245] Additional half-life extending mutation(s) that may be considered includes any one or more of N434H, N434A, T250Q, P257I, Q311I. D376V, T307A, and E380A (EU numbering). In some embodiments, a half-life extending mutation comprises T250Q / M428L, P257I / Q31 II, P257I / N434H, D376V / N434H, T307A / E380A / N434A, or M428L / N434A.

[0246] In certain embodiments, the antibody or antigen-binding fragment (e.g., comprising an IgGl isotype) has an in vivo half-life in a mouse (e.g., a tg32 mouse) in a range from about 10 days to about 17 days, about 10 days to about 16 days, about 10 days to about 15 days, about 10 days to about 14 days, about 10 days to about 13 days, about 10 days to about

[0247] 12 days, about 11 days to about 17 days, about 11 days to about 16 days, about 11 days to about 15 days, about 11 days to about 14 days, about 11 days to about 13 days, about 11 days to about 12 days, about 12 days to about 17 days, about 12 days to about 16 days, about 12 days to about 15 days, about 12 days to about 14 days, about 12 days to about 13 days, about 12.5 days to about 16 days, about 12.5 days to about 15.5 days, about 12.5 days to about 15 days, about 12.5 days to about 14.5 days, about 12.5 days to about 14 days, about 12.5 days to about 13.5 days, about 12.5 days to about 13 days, about 13 days to about 16 days, about

[0248] 13 days to about 15.5 days, about 13 days to about 15 days, about 13 days to about 14.5 days about 13 days to about 14 days, about 13 days to about 13.5 days, about 13.5 days to about 16 days, about 13.5 days to about 15.5 days, about 13.5 days to about 15 days, about 13.5 days to about 14.5 days, about 13.5 days to about 14 days, about 14 days to about 16 days, about

[0249] 14 days to about 15.5 days, about 14 days to about 15 days, about 14 days to about 14.5 days, about 14.5 days to about 16 days, about 14.5 days to about 15.5 days, about 14.5 days to about 15 days, about 15 days to about 16 days, about 15 days to about 15.5 days, about 15.5 days to about 16 days, or of about 10, 11, 12, 12.5, 13, 13.5, 14, 14.5, 15, 15.5, 16, or 17 days.

[0250] FcR binding can be mediated by the interaction of the Fc moiety (of an antibody) with Fc receptors (FcRs), which are specialized cell surface receptors on cells including hematopoietic cells. Fc receptors belong to the immunoglobulin superfamily, and have been shown to mediate both the removal of antibody-coated pathogens by phagocytosis of immune complexes, and the lysis of erythrocytes and various other cellular targets (e.g. tumor cells)

[0251] 41

[0252] 178476135.1 coated with the corresponding antibody, via antibody dependent cell mediated cytotoxicity (ADCC; Van de Winkel, J. G., and Anderson, C. L., J. Leukoc. Biol. 49 (1991) 511-524). FcRs are defined by their specificity for immunoglobulin classes; Fc receptors for IgG antibodies are referred to as FcyR, for IgE as FcsR, for IgA as FcaR and so on, and neonatal Fc receptors are referred to as FcRn. Fc receptor binding is described, for example, in Ravetch, J. V, and Kinet, J. P.. Annu. Rev. Immunol. 9 (1991) 457-492; Capel, R J., et al., Immunomethods 4 (1994) 25-34; de Haas, M., et al., J Lab. Clin. Med. 126 (1995) 330-341; and Gessner, J. E., et al., Ann. Hematol. 76 (1998) 231-248.

[0253] Cross-linking of receptors by the Fc region of native IgG antibodies (FcyR) triggers a wide variety of effector functions including phagocytosis, antibody-dependent cellular cytotoxicity, and release of inflammatory mediators, as well as immune complex clearance and regulation of antibody production. Fc moieties providing cross-linking of receptors (e.g., FcyR) are contemplated herein. In humans, three classes of FcyR have been characterized to- date, which are: (i) FcyRI (CD64), which binds monomeric IgG with high affinity and is expressed on macrophages, monocytes, neutrophils and eosinophils; (ii) FcyRII (CD32), which binds complexed IgG with medium to low affinity, is widely expressed, in particular on leukocytes, is believed to be a central player in antibody-mediated immunity, and which can be divided into FcyRIIA, FcyRIIB and FcyRIIC, which perform different functions in the immune system, but bind with similar low affinity to the IgG-Fc, and the ectodomains of these receptors are highly homologous; and (iii) FcyRIII (CD 16). which binds IgG with medium to low affinity and has been found in two forms: FcyRIIIA, which has been found on NK cells, macrophages, eosinophils, and some monocytes and T cells, and is believed to mediate ADCC; and FcyRIIIB, which is highly expressed on neutrophils.

[0254] FcyRIIA is found on many cells involved in killing (e.g. macrophages, monocytes, neutrophils) and seems able to activate the killing process. FcyRIIB seems to play a role in inhibitory processes and is found on B-cells, macrophages and on mast cells and eosinophils. Importantly, it has been show n that 75% of all FcyRIIB is found in the liver (Ganesan, L. P. et al., 2012: "FcyRIIb on liver sinusoidal endothelium clears small immune complexes," Journal of Immunology 189: 4981-4988). FcyRIIB is abundantly expressed on Liver Sinusoidal Endothelium, called LSEC, and in Kupffer cells in the liver and LSEC are the major site of small immune complexes clearance (Ganesan, L. P. et al., 2012: FcyRIIb on liver sinusoidal endothelium clears small immune complexes. Journal of Immunology' 189: 4981-4988).

[0255] 42

[0256] 178476135.1 On B cells, FcyRIIB may function to suppress further immunoglobulin production and isotype switching to. for example, the IgE class. On macrophages, FcyRIIB is thought to inhibit phagocytosis as mediated through FcyRIIA. On eosinophils and mast cells, the B form may help to suppress activation of these cells through IgE binding to its separate receptor.

[0257] In certain embodiments, the Fc polypeptide or fragment thereof comprises an effector function enhancing mutation. In certain embodiments, an antibody or antigen-binding fragment can comprise a Fc polypeptide or fragment thereof comprising a mutation G236A / A330L / I332E (EU numbering, also referred to herein as "GAALIE"). In some embodiments, the Fc polypeptide or fragment thereof does not comprise S239D. In some embodiments, the Fc polypeptide or fragment thereof comprises serine (S) at position 239 (EU numbering). An antibody having GAALIE mutations may comprise the amino acid sequence set forth in any one of SEQ ID NOS: 43-48 and 92-115.

[0258] In certain embodiments, an antibody or antigen-binding fragment can comprise a Fc polypeptide or fragment thereof comprising G236A / Y300L mutations (EU numbering, also referred to as "GAYL"). An antibody having GAYL mutations may comprise the amino acid sequence set forth in any one of SEQ ID NOS: 49-54 and 68-91.

[0259] In certain embodiments, the Fc polypeptide of an antibody or antigen-binding fragment comprises a half-life extending mutation and an effector function enhancing mutation. In certain embodiments, an antibody or antigen-binding fragment can comprise a Fc polypeptide or fragment thereof comprising G236A / Y300L / M428L / N434S mutations (EU numbering; also referred to as '‘GAYL + LS” or “GAYL-LS” or “LS-GAYL” or “LS + GAYL”). An antibody having GAYL + LS mutations may comprise the amino acid sequence set forth in any one of SEQ ID NOS:68-79.

[0260] In certain embodiments, an antibody or antigen-binding fragment can comprise a Fc polypeptide or fragment thereof comprising G236A / Y300L / M252Y / S254T / T256E (EU numbering; also referred to as “GAYL + YTE” or “GAYL-YTE” or “YTE-GAYL” or “YTE + GAYL”). An antibody having GAYL + YTE mutations may comprise the amino acid sequence set forth in any one of SEQ ID NOS: 80-91.

[0261] In certain embodiments, an antibody or antigen-binding fragment can comprise a Fc polypeptide or fragment thereof comprising G236A / A330L / I332E / M428L / N434S mutations (EU numbering, also referred to as “GAALIE + LS” or “GAALIE-LS” or “LS + GAALIE” or “LS-GAALIE”). An antibody having GAALIE + LS mutations may comprise the amino acid sequence of any one of SEQ ID NOS: 92-103.

[0262] 43

[0263] 178476135.1 In certain embodiments, an antibody or antigen-binding fragment can comprise a Fc polypeptide or fragment thereof comprising G236A / A330L / I332E / M252Y / S254T / T256E (EU numbering; also referred to as “GAALIE + YTE” or '‘GAALIE + YTE” or “YTE- GAALIE” or “YTE + GAALIE”). An antibody having GAALIE + YTE mutations may comprise the amino acid sequence of any one of SEQ ID NOS: 104-115.

[0264] In certain embodiments, an antibody or antigen-binding fragment can comprise a Fc polypeptide or fragment thereof comprising any one or more of N434H, N434A, T250Q. P257I, Q311I, D376V, T307A, E380A (EU numbering). In some embodiments, a half-life extending mutation compnses T250Q / M428L, P257I / Q311I, P257I / N434H, D376V / N434H, T307A / E380A / N434A, or M428L / N434A.

[0265] Examples of further Fc polypeptide mutations for modifying effector function are provided as follows. Amino acid modifications that modify (e.g., improve, reduce, or ablate) Fc functionalities include, for example, the T250Q / M428L, M252Y / S254T / T256E, H433K / N434F, M428L / N434A, E233P / L234V / L235A / G236 + A327G / A330S / P331S, E333A, S239D / A330L / I332E. P257I / Q311, K326W / E333S, S239D / I332E / G236A, N297Q, K322A, S228P, L235E + E318A / K320A / K322A. L234A / L235 A (also referred to herein as "LALA"), and L234A / L235A / P329G mutations. S267E and L328F mutations enhance FcyRIIB binding.

[0266] Modification in native IgG of at least one of E233-G236, P238, D265, N297, A327 and P329 reduces binding to FcyRI. IgG2 residues at positions 233-236, substituted into corresponding positions IgGl and IgG4, reduces binding of IgGl and IgG4 to FcyRI by 103- fold and eliminated the human monocyte response to antibody-sensitized red blood cells (Armour, K. L., et al. Eur. J. Immunol. 29 (1999) 2613-2624).

[0267] An IgG mutation at any one or more of E233-G236. P238, D265, N297, A327, P329. D270, Q295, A327, R292 and K414 reduced binding for FcyRIIA.

[0268] Two allelic forms of human FcyRIIA are the "H131" variant, which binds to IgGl Fc with higher affinity, and the "R131" variant, which binds to IgGl Fc with low affinity. See, e.g., Bruhns et al., Blood 113:3716-3725 (2009).

[0269] Reduced binding to FcyRIIIA is found, e.g., for mutation of at least one of E233- G236, P238, D265, N297, A327, P329, D270, Q295, A327, S239, E269, E293, Y296, V303, A327, K338 and D376.

[0270] 44

[0271] 178476135.1 Two allelic forms of human FcyRIIIA are the "F158" variant, which binds to IgGl Fc with lower affinity, and the "VI 58" variant, which binds to IgGl Fc with higher affinity. See, e.g., Bruhns et al., Blood 113:3716-3725 (2009).

[0272] Two regions of native IgG Fc appear to be involved in interactions between FcyRIIs and IgGs, namely (i) the lower hinge site of IgG Fc, in particular amino acid residues L, L, G, G (234 - 237, EU numbering), and (ii) the adjacent region of the CH2 domain of IgG Fc, in particular a loop and strands in the upper CH2 domain adjacent to the lower hinge region, e.g. in a region of P331 (Wines, B.D., et al., J. Immunol. 2000; 164: 5313 - 5318).

[0273] In certain embodiments, a polypeptide comprises only the specified or recited amino acid mutations (e.g. substitutions), and does not comprise any further amino acid substitutions or mutations; e.g., relative to the reference polypeptide (e.g., a w ild-type Fc polypeptide or fragment thereof). For example, in some embodiments, a variant Fc polypeptide comprising the amino acid substitutions G236A / Y300L / M252Y / S254T / T256E does not comprise any other amino acid substitutions or mutations; i.e., comprises an amino acid sequence that is wild-type except for G236A. Y300L, M252Y, S254T, and T256E.

[0274] In certain embodiments, an antibody or antigen-binding fragment comprises an amino acid modification (e.g., a substitution mutation) to remove an undesired risk of oxidation, deamidation, and / or isomerization.

[0275] In certain embodiments, the antibody or antigen-binding fragment is capable of antibody dependent cellular phagocytosis (ADCP). An example of a method of antibody dependent cellular phagocytosis is described in Example 3.

[0276] In certain embodiments, the antibody or antigen-binding fragment is capable of inducing antigen presentation. An example of a method of measuring antigen presentation is described in Example 3. In certain embodiments, antigen presentation is determined by measuring monocyte derived dendritic cell activation. An example of a method of measuring monocyte derived dendritic cell activation is described in Example 3.

[0277] In certain embodiments, the antibody or antigen-binding fragment is capable of inducing T cell activation. An example of a method of measuring T cell activation is described in Example 3.

[0278] In certain embodiments, the antibody or antigen-binding fragment comprises a mutation that alters glycosylation, wherein the mutation that alters glycosylation comprises N297A, N297Q, or N297G, and / or the antibody or antigen-binding fragment is partially or fully aglycosylated and / or is partially or fully afucosylated. Host cell lines and methods of

[0279] 45

[0280] 178476135.1 making partially or fully aglycosylated or partially or fully afucosylated antibodies and antigen-binding fragments are known (see, e.g., PCT Publication No. WO 2016 / 181357; Suzuki et al. Clin. Cancer Res. 13(6): 1875-82 (2007); Huang et al. MAbs 6: 1-12 (2018)).

[0281] An antibody or antigen-binding fragment of the present disclosure can be fucosylated (e.g., comprising one or more fucosyl moiety7, and ty pically comprising a native (wild-type) fucosylation partem or a fucosylation partem that includes one or more additional, or fewer, fucosyl moieties as compared to native), or can be afucosylated. In particular, native IgGl antibodies carry a glycan site at N297, and this is typically the only site where a core fucose moiety may be found in the antibody, though some glycan sites may arise through mutation (e.g. in the variable domains) during antibody development. Fucosylation of an Fc polypeptide or fragment thereof, or of an antibody, can be affected by introducing amino acid mutations to introduce or disrupt a fucosylation site (e.g. a mutation at N297, such as N297Q or N297A, to disrupt formation of a glycan that can include a core fucose moiety ), though ty pically it is preferred to maintain N297 and the glycan thereof, such as by expressing the polypeptide in a host cell which has been genetically engineered to lack the ability (or have an inhibited or compromised ability) to fucosylate the polypeptide; by expressing the polypeptide under conditions in which a host cell is impaired in its ability7to fucosylate the polypeptide (e.g., in the presence of 2-fluoro-L-fucose (2FF)), or the like. An afucosylated polypeptide can comprise no fucose moieties, or substantially no fucose moieties, and / or can be expressed by a host cell that is genetically engineered to lack the ability (or have an inhibited or compromised ability ) to fucosylate the polypeptide and / or can be expressed under conditions in which a host cell is impaired in its ability to fucosylate the polypeptide (e.g., in the presence of 2-fluoro-L-fucose (2FF)). In some embodiments, a polypeptide does not comprise a core fucose moiety at Asn297. In some embodiments, afucosylated polypeptides have increased binding to FcyRIIIA. In some contexts, addition of 2FF to a culture media comprising host cells expressing an antibody' results in about 85% or more of the antibodies not carry ing a fucose moiety7. Accordingly, a plurality7of antibodies may be described as “afucosylated” when the plurality7was produced in the presence of 2FF or like reagent. In some contexts, a plurality of polypeptides or antibodies may be described as, for example, afucosylated, meaning that about 85% or more of the single polypeptide or antibody molecules of the plurality' do not comprise a fucose moiety'. In certain preferred embodiments, an afucosylated antibody or polypeptide or a population or a plurality thereof comprises an asparagine (N) at EU position 297. Fucosylation or lack thereof can be

[0282] 46

[0283] 178476135.1 assessed using, for example, mass spectrometry (e.g. Electrospray mass spectrometry (ESIMS)). In some embodiments, compositions are provided that comprise a plurality of any one or more of the presently disclosed polypeptides, wherein the composition comprises afucosylated polypeptides.

[0284] In some embodiments, the antibody comprises a heavy chain (HC) and a light chain (LC). wherein the HC and the LC comprise, consist essentially of, or consist of, amino acid sequences set forth in SEQ ID NOs.: 9 and 10, respectively, and is afucosylated.

[0285] In some embodiments, the antibody or antigen-binding fragment may comprise a Fc polypeptide or fragment thereof that comprises or consists of amino acid sequences having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, 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% identity to, or comprises or consists of, the amino acid sequences set forth in any one of SEQ ID NOs: 45, 51, 57, 64, 76-79, 88-91, 100-103, and 112-115. Unless otherwise specified, human IgGl Fc mutations discussed herein are identified with reference to the amino acid sequence provided in any one of SEQ ID NOs: 45, 51, 57, 64, 76-79, 88-91, 100- 103, and 112-115 or Table 4.

[0286] In certain embodiments, the antibody or antigen-binding fragment comprises a CDRH1, a CDRH2, a CDRH3, a CDRL1, a CDRL2, and a CDRL3, wherein the CDRH1, CDRH2, CDRH3, CDRL1, CDRL2. and CDRL3 comprise, consist essentially of, or consist of the amino acid sequences set forth in SEQ ID NOS: 1-6, respectively; and a Fc polypeptide or fragment thereof comprising substitution mutations, wherein the substitution mutations comprise: (a) G236A, Y300L, M428L and N434S; (b) G236A, Y300L, M252Y, S254T, and T256E; (c) G236A, A330L, I332E, M428L, and N434S; (d) G236A, A330L, I332E, M252Y, S254T, T256E; (e) M428L and N434S; or (f) M252Y, S254T, and T256E; wherein the amino acid residues are numbered according to the EU numbering system.

[0287] In certain embodiments, the antibody or antigen-binding fragment comprises a CDRH1, a CDRH2, a CDRH3, a CDRL1, a CDRL2, and a CDRL3, wherein the CDRH1, CDRH2, CDRH3, CDRL1, CDRL2. and CDRL3 comprise, consist essentially of, or consist of the amino acid sequences set forth in SEQ ID NOS: 1-5 and 121, respectively; and a Fc polypeptide or fragment thereof comprising substitution mutations, w herein the substitution mutations comprise: (a) G236A, Y300L, M428L and N434S; (b) G236A, Y300L, M252Y, S254T, and T256E; (c) G236A, A330L, I332E, M428L, and N434S; (d) G236A, A330L,

[0288] 47

[0289] 178476135.1 I332E, M252Y, S254T, T256E; (e) M428L and N434S; or (f) M252Y, S254T, and T256E; wherein the amino acid residues are numbered according to the EU numbering system.

[0290] In certain embodiments, the antibody or antigen-binding fragment comprises a CDRH1, a CDRH2, a CDRH3, a CDRL1, a CDRL2, and a CDRL3, wherein the CDRH1, CDRH2, CDRH3, CDRL1, CDRL2, and CDRL3 comprise, consist essentially of, or consist of the amino acid sequences set forth in SEQ ID NOS: 11-16. respectively; and a Fc polypeptide or fragment thereof comprising substitution mutations, wherein the substitution mutations comprise: (a) G236A, Y300L, M428L and N434S; (b) G236A, Y300L, M252Y, S254T, and T256E; (c) G236A, A330L, I332E, M428L, and N434S; (d) G236A, A330L, I332E, M252Y, S254T, T256E; (e) M428L and N434S; or (f) M252Y, S254T, and T256E; wherein the amino acid residues are numbered according to the EU numbering system.

[0291] In certain embodiments, the antibody or antigen-binding fragment comprises a CDRH1, a CDRH2, a CDRH3, a CDRL1, a CDRL2, and a CDRL3, wherein the CDRH1, CDRH2, CDRH3, CDRL1, CDRL2, and CDRL3 comprise, consist essentially of, or consist of the amino acid sequences set forth in SEQ ID NOS: 19, 2, 3, and 4, 20, 21, respectively; and a Fc polypeptide or fragment thereof comprising substitution mutations, wherein the substitution mutations comprise: (a) G236A, Y300L, M428L and N434S; (b) G236A, Y300L, M252Y, S254T, and T256E; (c) G236A, A330L, I332E, M428L, and N434S; (d) G236A, A330L, I332E, M252Y. S254T, T256E; (e) M428L and N434S; or (f) M252Y, S254T. and T256E; wherein the amino acid residues are numbered according to the EU numbering system.

[0292] In certain embodiments, the antibody or antigen-binding fragment comprises a CDRH1, a CDRH2, a CDRH3, a CDRL1, a CDRL2, and a CDRL3, wherein the CDRH1, CDRH2, CDRH3, CDRL1, CDRL2. and CDRL3 comprise, consist essentially of, or consist of the amino acid sequences set forth in SEQ ID NOS: 24-26 and 14-16, respectively; and a Fc polypeptide or fragment thereof comprising substitution mutations, wherein the substitution mutations comprise: (a) G236A, Y300L, M428L and N434S; (b) G236A, Y300L, M252Y, S254T, and T256E; (c) G236A, A330L, I332E, M428L, and N434S; (d) G236A, A330L, I332E, M252Y. S254T, T256E; (e) M428L and N434S; or (!) M252Y, S254T, and T256E; wherein the amino acid residues are numbered according to the EU numbering system.

[0293] In certain embodiments, the antibody or antigen-binding fragment comprises a CDRH1, a CDRH2, a CDRH3, a CDRL1. a CDRL2, and a CDRL3, wherein the CDRH1,

[0294] 48

[0295] 178476135.1 CDRH2, CDRH3, CDRL1, CDRL2, and CDRL3 comprise, consist essentially of, or consist of the amino acid sequences set forth in SEQ ID NOS: 11, 29, 30, and 14-16. respectively; and a Fc polypeptide or fragment thereof comprising substitution mutations, wherein the substitution mutations comprise: (a) G236A, Y300L, M428L and N434S; (b) G236A, Y300L, M252Y, S254T, and T256E; (c) G236A, A330L, I332E, M428L, and N434S; (d) G236A, A330L, I332E, M252Y. S254T, T256E; (e) M428L and N434S; or (f) M252Y, S254T, and T256E; wherein the amino acid residues are numbered according to the EU numbering system.

[0296] In some embodiments, the antibody or antigen-binding fragment comprises a VH and VL comprising the VH and VL amino acid sequences set forth in SEQ ID NOS: 7 and 8, respectively; and a Fc polypeptide or fragment thereof comprising substitution mutations, wherein the substitution mutations comprise: (a) G236A, Y300L, M428L and N434S; (b) G236A, Y300L, M252Y, S254T, and T256E; (c) G236A, A330L, I332E, M428L, and N434S; (d) G236A, A330L, I332E, M252Y, S254T, T256E; (e) M428L and N434S; or (f) M252Y, S254T, and T256E; wherein the amino acid residues are numbered according to the EU numbering system.

[0297] In some embodiments, the antibody or antigen-binding fragment comprises a VH and VL comprising the VH and VL amino acid sequences set forth in SEQ ID NOS: 17 and 18, respectively; and a Fc polypeptide or fragment thereof comprising substitution mutations, wherein the substitution mutations comprise: (a) G236A, Y300L. M428L and N434S; (b) G236A, Y300L, M252Y, S254T, and T256E; (c) G236A, A330L, I332E, M428L, and N434S; (d) G236A, A330L, I332E, M252Y, S254T, T256E; (e) M428L and N434S; or (f) M252Y, S254T, and T256E; wherein the amino acid residues are numbered according to the EU numbering system.

[0298] In some embodiments, the antibody or antigen-binding fragment comprises a VH and VL comprising the VH and VL amino acid sequences set forth in SEQ ID NOS: 22 and 23, respectively; and a Fc polypeptide or fragment thereof comprising substitution mutations, wherein the substitution mutations comprise: (a) G236A, Y300L, M428L and N434S; (b) G236A, Y300L, M252Y, S254T, and T256E; (c) G236A. A330L, I332E. M428L, and N434S; (d) G236A, A330L, I332E, M252Y, S254T, T256E; (e) M428L and N434S; or (f) M252Y, S254T, and T256E; wherein the amino acid residues are numbered according to the EU numbering system.

[0299] 49

[0300] 178476135.1 In some embodiments, the antibody or antigen-binding fragment comprises a VH and VL comprising the VH and VL amino acid sequences set forth in SEQ ID NOS: 27 and 28, respectively; and a Fc polypeptide or fragment thereof comprising substitution mutations, wherein the substitution mutations comprise: (a) G236A, Y300L, M428L and N434S; (b) G236A, Y300L, M252Y, S254T, and T256E; (c) G236A, A330L, I332E, M428L, and N434S; (d) G236A, A330L, I332E, M252Y, S254T, T256E; (e) M428L and N434S; or (f) M252Y, S254T, and T256E; wherein the amino acid residues are numbered according to the EU numbering system.

[0301] In some embodiments, the antibody or antigen-binding fragment comprises a VH and VL comprising the VH and VL amino acid sequences set forth in SEQ ID NOS: 31 and 32, respectively; and a Fc polypeptide or fragment thereof comprising substitution mutations, wherein the substitution mutations comprise: (a) G236A, Y300L, M428L and N434S; (b) G236A, Y300L, M252Y, S254T, and T256E; (c) G236A, A330L, I332E, M428L, and N434S; (d) G236A, A330L, I332E, M252Y, S254T, T256E; (e) M428L and N434S; or (f) M252Y, S254T, and T256E; wherein the amino acid residues are numbered according to the EU numbering system.

[0302] Polynucleotides, Vectors, and Host cells

[0303] In another aspect, the present disclosure provides isolated polynucleotides that encode any of the presently disclosed antibodies or an antigen-binding fragment, or a portion thereof (e.g. , a CDR, a VH, a VL, a heavy chain, or a light chain). In certain embodiments, the polynucleotide is codon-optimized for expression in a host cell. Once a coding sequence is known or identified, codon optimization can be performed using known techniques and tools, e.g., using the GenScript® OptimiumGene™ tool, or the like. Codon-optimized sequences include sequences that are partially codon-optimized (i.e., one or more codon is optimized for expression in the host cell) and those that are fully codon-optimized.

[0304] It will also be appreciated that polynucleotides encoding antibodies and antigenbinding fragments of the present disclosure may possess different nucleotide sequences while still encoding a same antibody or antigen-binding fragment due to, for example, the degeneracy of the genetic code, splicing, and the like.

[0305] In any of the presently disclosed embodiments, the polynucleotide can comprise deoxyribonucleic acid (DNA) or ribonucleic acid (RNA). In some embodiments, the RNA comprises messenger RNA (mRNA).

[0306] 50

[0307] 178476135.1 In specific embodiments, polynucleotides encoding antibodies or antigen-binding fragments that bind CD4 binding site of HIV- 1 env comprise nucleotides encoding a VH and / or VL of Table 1 or Table 2 in a polynucleotide sequence, and / or at least two portions of any of the preceding sequences encoding a CDRH1, CDRH2, CDRH3, CDRL1, CDRL2, or CDRL1, and / or a functional variant thereof comprising nucleotides that encode the same protein or a protein with one, two, or three amino acid substitutions, one or more of which substitutions is optionally a conservative substitution and / or is a substitution to a germline- encoded amino acid, and / or a nucleotide sequence having at least 80% (e.g., 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or more) identity to the nucleotide sequence.

[0308] In specific embodiments, polynucleotides encoding antibodies or antigen-binding fragments that bind CD4 binding site of HIV-1 env comprise nucleotides encoding a heavy chain and / or light chain of Table 2 or Table 4 in a polynucleotide sequence.

[0309] Vectors are also provided, wherein the vectors comprise or contain a polynucleotide as disclosed herein (e.g., a polynucleotide that encodes an antibody or antigen-binding fragment that binds to CD4 binding site of HIV- 1 env). A vector can comprise any one or more of the vectors disclosed herein. In particular embodiments, a vector is provided that comprises a DNA plasmid construct encoding the antibody or antigen-binding fragment, or a portion thereof (e.g., so-called "DMAb"; see, e.g.. Muthumani el al., J Infect Dis. 274(3):369- 378 (2016); Muthumani et al.. Hum Vaccin Immunother 9:2253-2262 (2013)); Flingai et al., Sci Rep. 5: 12616 (2015); and Elliott et al. , NPJ Vaccines 18 (2017), which antibody-coding DNA constructs and related methods of use, including administration of the same, are incorporated herein by reference). In certain embodiments, a DNA plasmid construct comprises a single open reading frame encoding a heavy chain and a light chain (or a VH and a VL) of the antibody or antigen-binding fragment, wherein the sequence encoding the heavy chain and the sequence encoding the light chain are optionally separated by polynucleotide encoding a protease cleavage site and / or by a polynucleotide encoding a self-cleaving peptide. In some embodiments, the substituent components of the antibody or antigenbinding fragment are encoded by a polynucleotide comprised in a single plasmid. In other embodiments, the substituent components of the antibody or antigen-binding fragment are encoded by a polynucleotide comprised in two or more plasmids (e.g., a first plasmid comprises a polynucleotide encoding a heavy chain, VH, or VH+CH, and a second plasmid comprises a polynucleotide encoding the cognate light chain, VL, or VL+CL). In certain

[0310] 51

[0311] 178476135.1 embodiments, a single plasmid comprises a polynucleotide encoding a heavy chain and / or a light chain from two or more antibodies or antigen-binding fragments of the present disclosure. In some embodiments, the vector comprises a plasmid vector or a viral vector. In some embodiments, the viral vector is a retroviral vector, such as a lentiviral vector. An exemplary expression vector is pVaxl, available from Invitrogen®. A DNA plasmid of the present disclosure can be delivered to a subject by, for example, electroporation (e.g., intramuscular electroporation), or with an appropriate formulation (e.g, hyaluronidase).

[0312] In a further aspect, the present disclosure also provides a host cell expressing or capable of expressing an antibody or antigen-binding fragment according to the present disclosure; or comprising or containing a vector or polynucleotide according to the present disclosure.

[0313] Examples of such cells include but are not limited to, eukaryotic cells, e.g., yeast cells, animal cells, insect cells, plant cells; and prokaryotic cells, including E. coli. In some embodiments, the cells are mammalian cells, such as B cells. In some embodiments, the cells are human cells, such as human B cells. In certain embodiments, the B cell is immortalized. In certain such embodiments, the cells are a mammalian cell line such as CHO cells (e.g., DHFR- CHO cells (Urlaub et al., PNAS 77A2 6 (1980)), human embryonic kidney cells (e.g, HEK293T cells), PER.C6 cells, Y0 cells, Sp2 / 0 cells. NSO cells, human liver cells, e.g. Hepa RG cells, myeloma cells or hybridoma cells. Other examples of mammalian host cell lines include mouse sertoli cells (e.g, TM4 cells); monkey kidney CV1 line transformed by SV40 (COS-7); baby hamster kidney cells (BHK); African green monkey kidney cells (VERO-76); monkey kidney cells (CV1); human cervical carcinoma cells (HELA); human lung cells (W138); human liver cells (Hep G2); canine kidney cells (MDCK; buffalo rat liver cells (BRL 3A); mouse mammary tumor (MMT 060562); TRI cells; MRC 5 cells; and FS4 cells. Mammalian host cell lines suitable for antibody production also include those described in, for example, Yazaki and Wu, Methods in Molecular Biology, Vol. 248 (B. K. C. Lo, ed., Humana Press, Totowa, N.J.), pp. 255-268 (2003).

[0314] In certain embodiments, a host cell is a prokaryotic cell, such as an E. coli. The expression of peptides in prokaryotic cells such as E. coli is well established (see, e.g., Pluckthun, A. Bio / Technology 9:545-551 (1991). For example, antibodies may be produced in bacteria, in particular when glycosylation and Fc effector function are not needed. For expression of antibody fragments and polypeptides in bacteria, see, e.g., U.S. Pat. Nos. 5,648,237; 5.789,199; and 5.840,523.

[0315] 52

[0316] 178476135.1 In particular embodiments, the host cell may be transfected with a vector according to the present description. The term "transfection" refers to the introduction of nucleic acid molecules, such as DNA or RNA (e.g. mRNA) molecules, into cells, such as into eukaryotic cells. In the context of the present description, the term "transfection" encompasses any method know n to the skilled person for introducing nucleic acid molecules into cells, such as into eukaryotic cells, including into mammalian cells. Such methods encompass, for example, electroporation, lipofection, e.g., based on cationic lipids and / or liposomes, calcium phosphate precipitation, nanoparticle based transfection, virus based transfection, or transfection based on cationic polymers, such as DEAE-dextran or polyethylenimine, etc. In certain embodiments, the introduction is non-viral.

[0317] Moreover, host cells of the present disclosure may be transfected stably or transiently with a vector according to the present disclosure, e.g. for expressing an antibody, or an antigen-binding fragment, according to the present disclosure. In such embodiments, the cells may be stably transfected with the vector as described herein. Alternatively, cells may be transiently transfected with a vector according to the present disclosure encoding an antibody or antigen-binding fragment as disclosed herein. In any of the presently disclosed embodiments, a polynucleotide may be heterologous to the host cell.

[0318] Accordingly, the present disclosure also provides recombinant host cells that heterologously express an antibody or antigen-binding fragment of the present disclosure. For example, the cell may be of a species that is different to the species from which the antibody was fully or partially obtained (e.g., CHO cells expressing a human antibody or an engineered human antibody). In some embodiments, the cell type of the host cell does not express the antibody or antigen-binding fragment in nature. Moreover, the host cell may impart a post-translational modification (PTM; e.g.. glycosylation or fucosylation), or a lack thereof, on the antibody or antigen-binding fragment that is not present in a native state of the antibody or antigen-binding fragment (or in a native state of a parent antibody from which the antibody or antigen binding fragment was engineered or derived). Such a PTM, or a lack thereof, may result in a functional difference (e.g, reduced immunogenicity). Accordingly, an antibody or antigen-binding fragment of the present disclosure that is produced by a host cell as disclosed herein may include one or more post-translational modification that is distinct from the antibody (or parent antibody) in its native state (e.g., a human antibody produced by a host cell can comprise one or more post-translational modification, or can

[0319] 53

[0320] 178476135.1 include fewer post-translational modification(s), such that it is distinct from the antibody when isolated from the human and / or produced by the native human B cell or plasma cell).

[0321] Insect cells useful expressing a binding protein of the present disclosure are known in the art and include, for example, Spodoptera frugipera Sf9 cells, Trichoplusia ni BTI- TN5B1-4 cells, and Spodoptera frugipera SfSWTOl "Mimic™" cells. See, e.g., Palmberger et al., J. Biotechnol. 753(3-4): 160-166 (2011). Numerous baculoviral strains have been identified which may be used in conjunction with insect cells, particularly for transfection of Spodoptera frugiperda cells.

[0322] Eukaiyotic microbes such as filamentous fungi or yeast are also suitable hosts for cloning or expressing protein-encoding vectors, and include fungi and yeast strains with "humanized" glycosylation pathways, resulting in the production of an antibody with a partially or fully human glycosylation pattern. See Gemgross, Nat. Biotech. 22: 1409-1414 (2004); Li et al., Nat. Biotech. 24:210-215 (2006).

[0323] Plant cells can also be utilized as hosts for expressing an antibody or antigen-binding fragment of the present disclosure. For example, PL ANTIBODIES™ technology (described in, for example, U.S. Pat. Nos. 5,959,177; 6,040,498; 6.420,548; 7.125,978; and 6.417,429) employs transgenic plants to produce antibodies.

[0324] In certain embodiments, the host cell comprises a mammalian cell. In particular embodiments, the host cell is a B cell, CHO cell, an ExpiCHO cell, aHEK293 cell, a PER.C6 cell, a Y0 cell, a Sp2 / 0 cell, a NS0 cell, a human liver cell, a myeloma cell, or a hybridoma cell.

[0325] In a related aspect, the present disclosure provides methods for producing an antibody or antigen-binding fragment, wherein the methods comprise culturing a host cell of the present disclosure under conditions and for a time sufficient to produce the antibody, or the antigen-binding fragment. Methods useful for isolating and purifying recombinantly produced antibodies, by way of example, may include obtaining supernatants from suitable host cell / vector systems that secrete the recombinant antibody into culture media and then concentrating the media using a commercially available filter. Following concentration, the concentrate may be applied to a single suitable purification matrix or to a series of suitable matrices, such as an affinity matrix or an ion exchange resin. One or more reverse phase HPLC steps may be employed to further purify a recombinant polypeptide. These purification methods may also be employed when isolating an antibody from its natural environment. Methods for large scale production of one or more of the isolated / recombinant

[0326] 54

[0327] 178476135.1 antibodies described herein include batch cell culture, which is monitored and controlled to maintain appropriate culture conditions. Purification of soluble antibodies may be performed according to methods described herein and known in the art and that comport with laws and guidelines of domestic and foreign regulatory agencies.

[0328] Compositions

[0329] Also provided herein are compositions that comprise a presently disclosed antibody, antigen-binding fragment, polynucleotide, vector, or host cell, singly or in any combination, and can further comprise a pharmaceutically acceptable carrier, excipient, or diluent. Such compositions, as well as carriers, excipients, and diluents, are discussed in further detail herein. In some embodiments, the composition includes two or more antibodies or antigenbinding fragments thereof, one of which is described in Tables 1, 2, and 4.

[0330] In certain embodiments, the two antibodies or antigen-binding fragments thereof may exhibit improved or synergistic neutralization or prevention or / treatment of infection by HIV-1.

[0331] In certain embodiments, a composition comprises a first vector comprising a first plasmid, and a second vector comprising a second plasmid, wherein the first plasmid comprises a polynucleotide encoding a heavy chain, VH, or VH+CH, and a second plasmid comprises a polynucleotide encoding the cognate light chain, VL, or VL+CL of the antibody or antigen-binding fragment. In certain embodiments, a composition comprises a polynucleotide (e.g., mRNA) coupled to a suitable delivery vehicle or carrier. Exemplary vehicles or carriers for administration to a human subject include a lipid or lipid-derived delivery vehicle, such as a liposome, solid lipid nanoparticle, oily suspension, submicron lipid emulsion, lipid microbubble, inverse lipid micelle, cochlear liposome, lipid microtubule, lipid microcylinder, or lipid nanoparticle (LNP) or a nanoscale platform (see, e.g, Li et al. Wilery Inter dis cip Rev. Nanomed Nanobiotechnol. 77(2):el530 (2019)). Principles, reagents, and techniques for designing appropriate mRNA and formulating mRNA-LNP and delivering the same are described in, for example, Pardi et al. (J Control Release 277345-351 (2015)); Thess et al. (Mol Ther 23: 1456-1464 (2015)); Thran et l. (EMBO Mol Med 9(10): 1434- 1448 (2017); Kose et al. (Sci. Immunol. 4 eaaw6647 (2019); and Sabnis et a (Mol. Ther. 26: 1509-1519 (2018)), which techniques, include capping, codon optimization, nucleoside modification, purification of mRNA, incorporation of the mRNA into stable lipid nanoparticles (e.g.. ionizable cationic lipid / phosphatidylcholine / cholesterol / PEG-lipid;

[0332] 55

[0333] 178476135.1 ionizable lipid:distearoyl PC: cholesterol polyethylene glycol lipid), and subcutaneous, intramuscular, intradermal, intravenous, intraperitoneal, and intratracheal administration of the same, are incorporated herein by reference.

[0334] In some embodiments, the composition includes two or more antibodies or antigenbinding fragments having a VH and / or a VL according to an antibody described in Table 2, or having at least 85%. at least 90%. at least 95%, or at least 98% sequence identity’ thereto, or having a combination of CDRH1-3 and / or CDRL1-3 according to any antibody described in, Table 1.

[0335] Methods and Uses

[0336] Also provided herein are methods of treating or preventing a subject using an antibody or antigen-binding fragment, nucleic acid, vector, cell, or composition of the present disclosure, or a composition comprising the same, wherein the subject has, is believed to have, or is at risk for having an infection by HIV-1. "Treat," "treatment," or "ameliorate" refers to medical management of a disease, disorder, or condition of a subject (e.g, a human or non-human mammal, such as a primate, horse, cat, dog, goat, mouse, or rat). In general, an appropriate dose or treatment regimen comprising an antibody or binding fragment, nucleic acid, vector, cell, or composition of the present disclosure is administered in an amount sufficient to elicit a therapeutic or prophylactic benefit. Therapeutic or prophylactic / preventive benefit includes failure to develop a disease, disorder, or condition, delayed onset of clinical symptoms of the disease in a susceptible subject, improved clinical outcome; lessening or alleviation of symptoms associated with a disease; decreased occurrence of symptoms; improved quality of life; longer disease-free status; diminishment of extent of disease, stabilization of disease state; delay or prevention of disease progression; remission; survival; prolonged survival; or any combination thereof. In certain embodiments, therapeutic benefit includes reduction or prevention of hospitalization for treatment of an HIV-1 infection (i.e., in a statistically significant manner). In certain embodiments, therapeutic benefit includes a reduced duration of hospitalization for treatment of an HIV-1 infection (i.e., in a statistically significant manner). A therapeutic treatment can be a treatment administered to a subject infected with HIV-1 but who does not exhibit signs of a disease or exhibits only early signs, for the purpose of decreasing the risk of developing pathology. A therapeutic treatment can also be a treatment administered to a subject after signs and symptoms of the disease have developed. In certain embodiments, therapeutic

[0337] 56

[0338] 178476135.1 benefit includes reversing a late-stage disease pathology and / or reducing mortality. Of note, the terms "treatment" and "therapy " / "therapeutic" for HIV-1 infection include (complete) cure as well as attenuation / reduction of HIV- 1 infection and / or related symptoms (e.g., attenuation / reduction of severity of infection and / or symptoms, number of symptoms, duration of infection and / or symptoms, or any combination thereof). A prophylactic treatment can be a treatment administered to a subject not infected with HIV-1 for the purpose of prevention of HIV- 1 infection, including pre- and post-exposure prophylaxis.

[0339] A "therapeutically effective amount" or "effective amount" of an antibody, antigenbinding fragment, polynucleotide, vector, host cell, or composition of this disclosure refers to an amount of the composition or molecule sufficient to result in a therapeutic effect, including improved clinical outcome; lessening or alleviation of symptoms associated with a disease; decreased occurrence of symptoms; improved quality of life; prevention of one or more signs or symptoms of disease from developing; longer disease-free status; diminishment of extent of disease, stabilization of disease state; delay of disease progression; remission; survival; or prolonged survival in a statistically significant manner. When referring to an individual active ingredient, administered alone, a therapeutically effective amount refers to the effects of that ingredient or cell expressing that ingredient alone. When referring to a combination, a therapeutically effective amount refers to the combined amounts of active ingredients or combined adjunctive active ingredient with a cell expressing an active ingredient that results in a therapeutic effect, whether administered serially, sequentially, or simultaneously.

[0340] Accordingly, in certain embodiments, methods are provided for treating or preventing an HIV-1 infection in a subject, wherein the methods comprise administering to the subject an effective amount of an antibody, antigen-binding fragment, polynucleotide, vector, host cell, or composition as disclosed herein. In certain embodiments, the subject is human. In certain embodiments, the subject is HIV positive for the purposes of therapeutic treatment. In certain embodiments, the subject is HIV negative for the purpose of prophylactic treatment.

[0341] Subjects that can be treated by the present disclosure are, in general, human and other primate subjects, such as monkeys and apes for veterinary medicine purposes. Other model organisms, such as mice and rats, may also be treated according to the present disclosure. In any of the aforementioned embodiments, the subject may be a human subject. The subjects can be male or female and can be any suitable age, including infant juvenile, adolescent, adult, and geriatric subjects.

[0342] 57

[0343] 178476135.1 A number of criteria are believed to contribute to high risk for severe symptoms or death associated with an HIV-1 infection. These include, but are not limited to, age, occupation, general health, pre-existing health conditions, locale, and lifestyle habits. In some embodiments, a subject treated according to the present disclosure comprises one or more risk factors.

[0344] In certain embodiments, a human subject treated according to the present disclosure is an infant, a child, a young adult, an adult of middle age. or an elderly person. In certain embodiments, a human subject treated according to the present disclosure is less than 1 year old, or is 1 to 5 years old, or is between 5 and 125 years old (e.g., 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, or 125 years old, including any and all ages therein or therebetween). In certain embodiments, a human subject treated according to the present disclosure is 0-19 years old, 20-44 years old, 45-54 years old, 55-64 years old, 65-74 years old, 75-84 years old, or 85 years old, or older. Persons of middle, and especially of elderly age are believed to be at particular risk. In particular embodiments, the human subject is 20-44 years old, 45-54 years old, 55-64 years old, 65-74 years old, or older. In some embodiments, the human subject is male. In some embodiments, the human subject is female.

[0345] In a therapeutic setting, the subject is typically infected with HIV-1, diagnosed with HIV-1 infection, and / or showing symptoms of HIV- 1 infection. In some embodiments, the subject is infected with HIV-1 and has been virologically suppressed for at least 6 months. Virological suppression can have been achieved through the use of antiretroviral medication. In some embodiments, virological suppression is defined by HIV-RNA levels, also referred to as viral load, in the blood or plasma of <50 copies / mL. In some embodiments, the antiretroviral medication is a nucleoside reverse transcriptase inhibitor (NRTI). nonnucleoside reserve transcriptase inhibitor (NNRTI), protease inhibitor (PI), fusion inhibitor, CCR5 antagonist, integrase strand transfer inhibitor (INSTI), attachment inhibitor, postattachment inhibitor, capsid inhibitor, pharmocokinetic enhancer, or any combination thereof. In some embodiments, the antiretroviral medication is a long-acting antiretroviral medication which can include, but are not limited to, cabotegravir, rilpivinne, and lenacapavir. In some embodiments, the antibody or antigen-binding fragment is administered to the subject in combination with an antiretroviral medication, such as a long-acting antiretroviral medication. In some embodiments, the antibody or antigen-binding fragment is not administered in combination with an antiretroviral medication. In some embodiments,

[0346] 58

[0347] 178476135.1 treatment of the subject with the antibody or antigen-binding fragment results in viral suppression for at least 6 months, at least 9 months, or at least 12 months, following the administration of a single dose of the antibody or antigen-binding fragment. Viral suppression following treatment can be a blood or plasma HIV-RNA level of <50 copies / mL.

[0348] In some embodiments, the treatment of the subject infected with HIV-1 with a single dose of the antibody or antigen-binding fragment, polynucleotide, vector, host cell, or composition of the present disclosure results in maintenance of blood or plasma levels of HIV-RNA below 50 copies / mL for at least 6 months. In some embodiments, blood or plasma levels of HIV-RNA below 50 copies / mL are maintained for at least one year following administration of the single dose. In some embodiments, administration of a long-acting antiretroviral in combination with the single dose antibody or antigen-binding fragment, polynucleotide, vector, host cell, or composition of the present disclosure is required to maintain a blood or plasma level of HIV-RNA below 50 copies / mL. In some embodiments, a long-acting antiretroviral is not administered in combination with the single dose in order to maintain a blood or plasma level of HIV-RNA below 50 copies / mL.

[0349] In certain embodiments, the antibody, antigen-binding fragment, polynucleotide, vector, host cell, or composition as disclosed herein is administered to a subject who has received, is currently receiving, or will receive anti-retroviral therapy. In certain embodiments, the subject is infected with HIV-1. In certain embodiments, anti-retroviral therapy comprises a nucleoside reverse transcriptase inhibitor, a non-nucleoside reverse transcriptase inhibitor, a protease inhibitor, a fusion inhibitor, a CCR5 antagonist, an integrase strand transfer inhibitor, an attachment inhibitor, a post-attachment inhibitor, a capsid inhibitor, a pharmacokinetic enhancer, an anti-HIV antibody, a combination antiretroviral therapy, or any combination thereof. Examples of nucleoside reverse transcriptase inhibitors include abacavir, emtricitabine, lamivudine, tenofovir disoproxil fumarate, tenofovir alafenamide fumarate, zidovudine, or any combination thereof. Examples of non-nucleoside reverse transcriptase inhibitors include doravirine, efavirenz, etravirine, nevirapine, rilpivirine, or any combination thereof. Examples of protease inhibitors include atazanavir, darunavir, fosamprenavir, ritonavir, tipranavir, lopinavir, saquinavir, nelfinavir, or any combination thereof. A fusion inhibitor may comprise enfuvirtide. A CCR5 antagonist may comprise maraviroc. Examples of integrase strand transfer inhibitors include cabotegravir, dolutegravir, raltegravir, bictegravir, elvitegravir, or any combination thereof. An attachment inhibitor may comprise fostemsavir. A post-attachment inhibitor may comprise ibalizumab-

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[0351] 178476135.1 uiyk. A capsid inhibitor may comprise lenacapavir. A pharmacokinetic enhancer may comprise cobicistat. In some embodiments, an anti-HIV antibody is a broadly neutralizing antibody (bNAb). Examples of combination antiretroviral therapies, which contain two or more anti-HIV therapies from one or more drug classes, include: Epzicom (abacavir and lamivudine); Triumeq (abacavir, dolutegravir, and lamivudine); Trizivir (abacavir, lamivudine, and zidovudine); Evotaz (atazanavir and cobicistat); Biktarvy (bictegravir. emtricitabine, and tenofovir alafenamide); Cabenuva (cabotegravir and rilpivirine); Prezcobix (darunavir and cobicistat); Symtuza (darunavir, cobicistat, emtricitabine, and tenofovir alafenamide); Dovato (dolutegravir and lamivudine); Juluca (dolutegravir and rilpivirine); Destrigo (doravirine, lamivudine, and tenofovir disoproxil fumarate); Symfi (efavirenz, lamivudine, and tenofovir disoproxil fumarate); Genvoya (elvitegravir, cobicistat, emtricitabine, and tenofovir alafenamide); Stribild (elvitegravir, cobicistat, emtricitabine, and tenofovir disoproxil fumarate); Odefsey (emtricitabine, rilpivirine, and tenofovir alafenamide); Complera (emtricitabine, rilpivirine, and tenofovir disoproxil fumarate); Descovy (emtricitabine and tenofovir alafenamide); Truvada (emtricitabine and tenofovir disoproxil fumarate); Cimduo (lamivudine and tenofovir disoproxil fumarate); and Kaletra (lopinavir and ritonavir). Examples of broadly neutralizing anti-HIV antibodies include N6, N6-LS, 3BNC117, 3BNC117-LS, 10-1074, 10-1074-LS, VRC07, VRC07-523, and VRC07- 523-LS. N6 antibody binds to CD4 binding site of gp!20 (See, W02016154003, incorporated by reference in its entirety). N6-LS (also known as GSK3810109A; VH3810109) is an Fc modified version of N6 antibody containing N434S and M428L Fc modifications. 3BNC117 antibody targets the CD4 binding site on gpl20 (Scheid et al. Science (2011) 333: 1633-1637, U.S. Patent 9,783,594; each of which is incorporated by reference in its entirety). 3BNC117-LS. also known as teropavimab, is an Fc modified version of 3BNC 117 antibody containing N434S and M428L Fc modifications. 10-1074 antibody targets the HIV-1 envelope V3 glycan supersite (See, W02014063059, incorporated by reference in its entirety). 10-1074-LS, also know n as zinlirvimab, is an Fc modified version of 10-1074 antibody containing N434S and M428L Fc modifications. VRC07 antibody targets the CD4 binding site of gp!20 (See, U.S. Patent 9,695,230, incorporated by reference in its entirety). VRC07-523 antibody is an optimized version of VRC07, and VRC07-523-LS antibody is an Fc modified version ofVRC07-523 containing N434S and M428L Fc modifications (See, Wu et al., Science 329:856-861; and Asokan et al. Proc. Natl. Acad. Sci. 117: 18754-18763; each of which is incorporated by reference in its entirety). In

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[0353] 178476135.1 some embodiments, the anti-retroviral therapy comprises any anti-retroviral medication listed in Table 3, including any combination thereof.

[0354] TABLE 3. FDA- approved HIV medications as of July 31, 2024

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[0356] 178476135.1

[0357] It will be understood that reference herein to a reduced number and / or severity of symptoms, which reduction results from administration of a presently disclosed pharmaceutical composition, describes a comparison with a reference subject who did not receive a disclosed pharmaceutical composition. A reference subject can be, for example, (i) the same subj ect during an earlier period of time (e.g. , pre-HIV- 1 infection), (ii) a subj ect of a same or a similar: age or age group; gender; pregnancy status; chronic medical condition (such as chronic cardiac, pulmonary, renal, metabolic, neurodevelopmental, liver or hematologic diseases) or lack thereof; and / or immunosuppressive condition or lack thereof; or (iii) a typical subject within a population (e g., local, regional, or national, including of a same or similar age or age range and / or general state of health). Prophylaxis can be determined by, for example, the failure to develop a diagnosed HIV-1 infection.

[0358] In certain embodiments, the methods provided herein include administering a therapeutically effective amount of a composition according to the present disclosure to a subject at immediate risk of HIV- 1 infection.

[0359] Typical routes of administering the presently disclosed compositions include, without limitation, oral, topical, transdermal, inhalation, parenteral, sublingual, buccal, rectal, vaginal, and intranasal. The term "parenteral", as used herein, includes subcutaneous injections, intravenous, intramuscular, intrastemal injection or infusion techniques. In certain embodiments, administering comprises administering by a route that is selected from intravenous, parenteral, subcutaneous, transdermal, and intramuscular. In some embodiments, the method comprises subcutaneous administration of the antibody. In other embodiments, the method comprises intravenous administration of the antibody.

[0360] Pharmaceutical compositions according to certain embodiments of the present invention are formulated so as to allow the active ingredients contained therein to be bioavailable upon administration of the composition to a patient. Compositions that will be

[0361] 62

[0362] 178476135.1 administered to a subject or patient may take the form of one or more dosage units, where for example, a pre-filled syringe for subcutaneous administration or an infusion bag for intravenous administration may be a single dosage unit,. Actual methods of preparing such dosage forms are known, or will be apparent, to those skilled in this art; for example, see Remington: The Science and Practice of Pharmacy, 20th Edition (Philadelphia College of Pharmacy and Science, 2000). The composition to be administered will, in any event, contain an effective amount of an antibody or antigen-binding fragment, polynucleotide, vector, host cell, or composition of the present disclosure, for treatment of a disease or condition of interest in accordance with teachings herein.

[0363] Liquid pharmaceutical compositions, whether they be solutions, suspensions or other like form, may include one or more of the following adjuvants: sterile diluents such as water for injection, saline solution, preferably physiological saline, Ringer’s solution, isotonic sodium chloride, fixed oils such as synthetic mono or diglycerides which may serve as the solvent or suspending medium, polyethylene glycols, glycerin, propylene glycol or other solvents; antibacterial agents such as benzyl alcohol or methyl paraben; antioxidants such as ascorbic acid or sodium bisulfite; chelating agents such as ethylenediaminetetraacetic acid; buffers such as acetates, citrates or phosphates and agents for the adjustment of tonicity such as sodium chloride or dextrose. The parenteral preparation can be enclosed in ampoules, disposable syringes or multiple dose vials made of glass or plastic. Physiological saline is a preferred adjuvant. An injectable pharmaceutical composition is preferably sterile.

[0364] A liquid composition intended for either parenteral should contain an amount of an antibody or antigen-binding fragment as herein disclosed such that a suitable dosage will be obtained. Typically, this amount is at least 0.01% of the antibody or antigen-binding fragment in the composition. In certain embodiments, pharmaceutical compositions and preparations according to the present invention are prepared so that a parenteral dosage unit contains between 0.01 to 10% by weight of antibody or antigen-binding fragment prior to dilution.

[0365] In certain embodiments, the present disclosure provides a lyophilized pharmaceutical formulation of an antibody or antigen-binding fragment disclosed herein. “Lyophilized,” also referred to a “freeze-dried,” refers to a process by which the material to be dried is first frozen and then the ice or frozen solvent is removed by sublimation in a vacuum environment. An excipient may be included in the pre-lyophilized formulation to enhance the stability of the lyophilized product in storage. The lyophilized formulation enables

[0366] 63

[0367] 178476135.1 reconstitution of the antibody or antigen-binding fragment thereof by dissolving the lyophilized formulation in a diluent such that the antibody or antigen-binding fragment thereof is dispersed in the reconstituted formulation. The lyophilized formulation may be reconstituted at a desired concentration. In some embodiments, the reconstituted formulation is suitable for administration to the subject, e.g., parenteral administration, optionally, subcutaneous or intravenous administration. In some embodiments, the lyophilized formulation is reconstituted prior to administration to the subject. In some embodiments, the antibody or antigen-binding fragment formulation is lyophilized in the same container in which reconstitution takes place, e.g., a glass vial.

[0368] The pharmaceutical compositions may be prepared by methodology well known in the pharmaceutical art. For example, a composition intended to be administered by injection can be prepared by combining a composition that comprises an antibody or antigen-binding fragment as described herein and optionally, one or more of salts, buffers and / or stabilizers, with sterile, distilled water so as to form a solution. A surfactant may be added to facilitate the formation of a homogeneous solution or suspension. Surfactants are compounds that non- covalently interact with the peptide composition so as to facilitate dissolution or homogeneous suspension of the antibody or antigen-binding fragment in the aqueous delivery system.

[0369] In general, an appropriate dose and treatment regimen provide the composition(s) in an amount sufficient to provide therapeutic and / or prophylactic benefit (such as described herein, including an improved clinical outcome e.g., a decrease in frequency, duration, or severity of diarrhea or associated dehydration, or inflammation, or longer disease-free and / or overall survival, or a lessening of symptom severity). For prophylactic use, a dose should be sufficient to prevent, delay the onset of, or diminish the severity of a disease associated with disease or disorder. Prophylactic benefit of the compositions administered according to the methods described herein can be determined by performing pre-clinical (including in vitro and in vivo animal studies) and clinical studies and analyzing data obtained therefrom byappropriate statistical, biological, and clinical methods and techniques, all of which can readily be practiced by a person skilled in the art.

[0370] Compositions are administered in an effective amount (e.g., to HIV-1 infection), which will vary depending upon a variety of factors including the activity of the specific compound employed; the metabolic stability and length of action of the compound; the age, body weight, general health, sex, and diet of the subject; the mode and time of administration;

[0371] 64

[0372] 178476135.1 the rate of excretion; the drug combination; the severity of the particular disorder or condition; and the subject undergoing therapy. In certain embodiments, following administration of therapies according to the formulations and methods of this disclosure, test subjects will exhibit about a 10% up to about a 99% reduction in one or more symptoms associated with the disease or disorder being treated as compared to placebo-treated or other suitable control subjects.

[0373] Generally, a therapeutically effective dose of an antibody or antigen binding fragment is (for a 70 kg mammal) from about 0.001 mg / kg (z.e., 0.07 mg) to about 100 mg / kg (i.e., 7.0 g); preferably a therapeutically effective dose is (for a 70 kg mammal) from about 0.01 mg / kg (i.e., 0.7 mg) to about 50 mg / kg (i.e., 3.5 g); more preferably a therapeutically effective dose is (for a 70 kg mammal) from about 1 mg / kg (i.e.. 70 mg) to about 25 mg / kg (i.e., 1.75 g). For polynucleotides, vectors, host cells, and related compositions of the present disclosure, a therapeutically effective dose may be different than for an antibody or antigen-binding fragment.

[0374] In certain embodiments, an antibody or antigen-binding fragment of the present disclosure is administered intravenously to the subject at a dose from about 1 mg / kg (i.e., about 70 mg for a 70 kg mammal) to about 120 mg / kg (i.e., about 8,400 mg for a 70 kg mammal), about 2 mg / kg (i.e., about 140 mg) to about 115 mg / kg (i.e., about 8,050 mg), about 2 mg / kg (i.e., about 140 mg) to about 110 mg / kg (i.e., about 7,700 mg), about 2 mg / kg (i.e., about 140 mg) to about 50 mg / kg (i.e., about 3,500 mg), about 2 mg / kg (i.e., about 140 mg) to about 45 mg / kg (i.e., about 3,150 mg), about 5 mg / kg (i.e., about 350 mg) to about 115 mg / kg (i.e., about 8,050 mg), or about 5 mg / kg (i.e., about 350 mg) to about 110 mg / kg (i.e., about 7,700 mg).

[0375] In certain embodiments, an antibody or antigen-binding fragment of the present disclosure is administered intravenously to the subject at a dose of about 1 mg / kg (i.e., about 70 mg), about 2 mg / kg (i.e., about 140 mg), about 5 mg / kg (i.e., 350 mg), about 10 mg / kg (i.e., about 700 mg), about 15 mg / kg (i.e., about 1,050 mg), about 20 mg / kg (i.e., about 1,400 mg), about 25 mg / kg (i.e., about 1,750 mg), about 30 mg / kg (i.e., about 2,100 mg), about 35 mg / kg (i.e., about 2,450 mg), about 40 mg / kg (i.e., about 2,800 mg), about 45 mg / kg (i.e., about 3,150 mg), about 50 mg / kg (i.e., about 3,500 mg), about 55 mg / kg (i.e., about 3,850 mg), about 60 mg / kg (i.e., about 4,200 mg), about 65 mg / kg (i.e., about 4,550 mg), about 70 mg / kg (i.e., about 4,900 mg), about 75 mg / kg (i.e., about 5,250 mg), about 80 mg / kg (i.e., about 5,600 mg), about 85 mg / kg (i.e.. about 5,950 mg), about 90 mg / kg (i.e., about 6,300

[0376] 65

[0377] 178476135.1 mg), about 95 mg / kg (i.e., about 6,650 mg), about 100 mg / kg (i.e, about 700 mg), about 105 mg / kg (i.e., about 7,350 mg), about 110 mg / kg (i.e.. about 7,700 mg), about 115 mg / kg (i.e., about 8,050 mg), or about 120 mg / kg (i.e., about 8,400 mg).

[0378] In certain embodiments, an antibody or antigen-binding fragment of the present disclosure is administered intravenously to the subject at a dose of about 100 mg, 200 mg, 300 mg, 400 mg. 500 mg, 600 mg, 700 mg, 800 mg, 900 mg, 1000 mg, 1100 mg, 1200 mg, 1300 mg. 1400 mg, 1500 mg, 1600 mg, 1700 mg, 1800 mg. 1900 mg, 2000 mg, 2250 mg,

[0379] 2500 mg, 2750 mg, 3000 mg, 3250 mg, 3500 mg , 3750 mg, 4000 mg, 4250 mg, 4500 mg,

[0380] 4750 mg, 5000 mg, 5250 mg, 5500 mg, 5750 mg, 6000 mg, 6250 mg, 6500 mg, 6750 mg,

[0381] 7000 mg. 7250 mg, 7500 mg, 7750 mg, 8000 mg, 8250 mg. 8500 mg, 8750 mg, 9000 mg,

[0382] 9250 mg. 9500 mg, 9750 mg, 10000 mg, 11000 mg, 12000 mg. 13000 mg, 14000 mg, 15000 mg, 16000 mg, 17000 mg, 18000 mg, 19000 mg, 20000 mg, 22500 mg, or 25000 mg.

[0383] In certain embodiments, an antibody or antigen-binding fragment of the present disclosure is administered intravenously to the subject at a dose of about 50 mg / kg (about 3500 mg for a 70 kg mammal) to the subject. A dose of about 50 mg / kg is estimated to achieve 10-20 pg / ml trough concentration for 6 months or 40 pg / ml trough concentration for 4 months. Trough concentration is the concentration of a drug in the blood immediately before the next dose is administered. In certain embodiments, the antibody or antigenbinding fragment thereof is administered at a dose of about 50 mg / kg to the subject and the antibody or antigen-binding fragment is capable of achieving a serum concentration of at least about 10-20 pg / ml for 6 months or at least about 40 pg / ml for 4 months in the subject.

[0384] In certain embodiments, a method comprises administering a single dose of the antibody, antigen-binding fragment, polynucleotide, vector, host cell, or composition to the subject. In certain embodiments, a method comprises administering the antibody, antigenbinding fragment, polynucleotide, vector, host cell, or composition to the subject at 2, 3, 4, 5, 6, 7, 8, 9, 10 times, or more.

[0385] In certain embodiments, a method comprises administering the antibody, antigenbinding fragment, polynucleotide, vector, host cell, or composition to the subject a plurality of times, wherein a second or successive administration is performed at about 1 month, 2 months, 3 months, 4 months, 5 months , 6 months, 7 months, 8 months, 9 months, 10 months, 11 months, 12 months, 18 months, or 24 months, or more, following a first or prior administration, respectively.

[0386] 66

[0387] 178476135.1 In certain embodiments, a method comprises administering the antibody, antigenbinding fragment, polynucleotide, vector, host cell, or composition to the subject for at least 3 months, at least 6 months, at least 12 months, 18 months, 24 months, 36 months, 48 months, 60 months, 72 months, 84 months, 96 months, 108 months, 120 months, or longer.

[0388] In certain embodiments, a method comprises administering the antibody, antigenbinding fragment, polynucleotide, vector, host cell, or composition at least one time prior to the subject being infected by HIV-1.

[0389] Compositions comprising an antibody, antigen-binding fragment, polynucleotide, vector, host cell, or composition of the present disclosure may also be administered simultaneously with, prior to, or after administration of one or more other therapeutic agents, such as, for example, an antiretroviral listed in Table 3. Such combination therapy may include administration of a single pharmaceutical dosage formulation which contains a compound of the invention and one or more additional active agents, as well as administration of compositions comprising an antibody or antigen-binding fragment of the disclosure and each active agent in its own separate dosage formulation. For example, an antibody or antigen-binding fragment as described herein and the other active agent can be administered to the patient together in a single oral dosage composition such as a tablet or capsule, or each agent administered in separate oral dosage formulations. Similarly, an antibody or antigen-binding fragment as described herein and the other active agent can be administered to the subject together in a single parenteral dosage composition such as in a saline solution or other physiologically acceptable solution, or each agent administered in separate parenteral dosage formulations. Where separate dosage formulations are used, the compositions comprising an antibody or antigen-binding fragment and one or more additional active agents can be administered at essentially the same time, i.e., concurrently, or at separately staggered times, i.e., sequentially and in any order; combination therapy is understood to include all these regimens.

[0390] In some embodiments, an antibody (or one or more nucleic acid, host cell, vector, or composition) is administered to a subject who has previously received one or more antiretroviral, therapies such as any of those listed in Table 3. In some embodiments, the antiretroviral therapy is a long-acting antiretroviral, such as cabotegravir, rilpivirine, and / or lenacapavir.

[0391] In some embodiments, an antibody, polynucleotide, vector, or composition as described herein is administered to prevent or treat an HIV-1 infection.

[0392] 67

[0393] 178476135.1 In a related aspect, uses of the presently disclosed antibodies, antigen-binding fragments, vectors, host cells, and compositions (e.g, in the diagnosis, prophylaxis, and / or treatment of HIV- 1 infection, in the manufacture of a medicament for preventing or treating HIV-1 infection) are provided.

[0394] In certain embodiments, an antibody, antigen-binding fragment, polynucleotide, vector, host cell, or composition is provided for use in a method of treating an HIV-1 infection in a subject.

[0395] In certain embodiments, an antibody, antigen-binding fragment, or composition is provided for use in a method of manufacturing or preparing a medicament for treating or preventing HIV-1 infection in a subject.

[0396] The present disclosure further provides a kit comprising one or more of any antibodies, antigen-binding fragments, polynucleotides, nucleic acids, vectors, or other compositions disclosed herein. The kit may further include one or more of a container, such as a tube, vial, or syringe, an activator, a valve, a subcontainer, or instructions for use, such as for administering to a subject.

[0397] Also provided herein are methods for use of an antibody or antigen-binding fragment, nucleic acid, vector, cell, or composition of the present disclosure in the diagnosis of an HIV- 1 infection (e.g. , in a human subject, or in a sample obtained from a human subject).

[0398] Methods of diagnosis (e.g., in vitro, ex vivo) may include contacting an antibody, antibody fragment (e.g., antigen binding fragment) with a sample. Such samples may be isolated from a subject, for example an isolated tissue sample taken from, for example, nasal passages, sinus cavities, salivary' glands, lung, liver, pancreas, kidney, ear, eye, placenta, alimentary tract, heart, ovaries, pituitary, adrenals, thyroid, brain, skin or blood. The methods of diagnosis may also include the detection of an antigen / antibody complex, in particular following the contacting of an antibody or antibody fragment with a sample. Such a detection step can be performed at the bench, i.e. without any contact to the human or animal body. Examples of detection methods are well-known to the person skilled in the art and include, e.g., ELISA (enzyme-linked immunosorbent assay), including direct, indirect, and sandwich ELISA.

[0399] 68

[0400] 178476135.1 TABLE 4. ANTIBODY, CONSTANT DOMAIN, AND FC SEQUENCES

[0401] 69

[0402] 178476135.1

[0403] 70

[0404] 178476135.1

[0405] 71

[0406] 178476135.1

[0407] 72

[0408] 178476135.1

[0409] 73

[0410] 178476135.1

[0411] 74

[0412] 178476135.1

[0413] 75

[0414] 178476135.1

[0415] 76

[0416] 178476135.1

[0417] 178476135.1

[0418] 78

[0419] 178476135.1

[0420] 79

[0421] 178476135.1 Numbered Embodiments:

[0422] The following embodiments recite non-limiting permutations of combinations of features disclosed herein. Other permutations of combinations of features are also contemplated. In particular, each of these numbered embodiments is contemplated as depending from or relating to every7previous or subsequent numbered embodiment, independent of their order as listed.

[0423] Embodiment 1. An antibody or antigen-binding fragment thereof that is capable of binding to the CD4 binding site on env protein of human immunodeficiency virus type 1 (HIV-1), comprising: (i) a heavy chain variable domain (VH) comprising a complementarity7determining region (CDR)H1, a CDRH2, and a CDRH3 comprising the amino acid sequences set forth in SEQ ID NOS: 1-3, respectively; (ii) a light chain variable domain (VL) comprising a CDRL1 comprising the amino acid sequence of SEQ ID NO:4, a CDRL2 comprising the amino acid sequence of Thr-Ala-His (TAH), and a CDRL3 comprising the amino acid sequence of SEQ ID NO:6 or SEQ ID NO: 121; and (iii) a Fc polypeptide or fragment thereof comprising substitution mutations, wherein the substitution mutations comprise: (a) G236A, Y300L. M428L and N434S; (b) M428L and N434S; (c) M252Y. S254T, and T256E; (d) G236A, Y300L, M252Y, S254T, and T256E; (e) G236A, A330L, I332E, M428L, and N434S; or (f) G236A, A330L, I332E, M252Y, S254T, T256E; wherein the amino acid residues are numbered according to the EU numbering system.

[0424] Embodiment 2. The antibody or antigen-binding fragment thereof of embodiment 1. wherein the VH comprises, consists essentially of, or consists of an amino acid sequence having at least 80%, 85%, 90%, 95%, 97%, or 99% identity7to the amino acid sequence set forth in SEQ ID NO:7, and / or the VL comprises, consists essentially of, or consists of an amino acid sequence having at least 80%, 85%, 90%, 95%, 97%, or 99% identity to amino acid sequence set forth in SEQ ID NO: 8.

[0425] Embodiment 3. The antibody or antigen-binding fragment thereof of embodiment 1 or 2, wherein the VH comprises, consists essentially of, or consists of the amino acid sequence set forth in SEQ ID NO: 7, and / or the VL comprises or consists of the amino acid sequence set forth in SEQ ID NO: 8.

[0426] Embodiment 5. An antibody or antigen-binding fragment thereof that is capable of binding to the CD4 binding site on env protein of human immunodeficiency virus type 1 (HIV-1), comprising: (i) a heavy chain variable domain (VH) comprising a complementarity determining region (CDR)H1, a CDRH2, and a CDRH3 comprising the amino acid

[0427] 80

[0428] 178476135.1 sequences set forth in SEQ ID NOS: 11-13, respectively; (ii) a light chain variable domain (VL) comprising a CDRL1 comprising the amino acid sequence of SEQ ID NO: 14, a CDRL2 comprising the amino acid sequence of ‘ DGS’’, and a CDRL3 comprising the amino acid sequence of SEQ ID NO: 16; and (iii) a Fc polypeptide or fragment thereof comprising substitution mutations, wherein the substitution mutations comprise: (a) G236A, Y300L, M428L and N434S; (b) M428L and N434S; (c) M252Y, S254T, and T256E; (d) G236A, Y300L, M252Y. S254T. and T256E; (e) G236A, A330L. I332E, M428L, and N434S; or (1) G236A, A330L, I332E, M252Y, S254T, T256E; wherein the amino acid residues are numbered according to the EU numbering system.

[0429] Embodiment 6. The antibody or antigen-binding fragment thereof of embodiment 5, wherein the VH comprises, consists essentially of, or consists of an amino acid sequence having at least 80%, 85%, 90%, 95%, 97%, or 99% identity to the amino acid sequence set forth in SEQ ID NO: 17, and / or the VL comprises, consists essentially of, or consists of an amino acid sequence having at least 80%, 85%, 90%, 95%, 97%, or 99% identity to amino acid sequence set forth in SEQ ID NO: 18; or wherein the VH comprises, consists essentially of, or consists of the amino acid sequence set forth in SEQ ID NO: 17, and / or the VL comprises or consists of the amino acid sequence set forth in SEQ ID NO: 18.

[0430] Embodiment 7. An antibody or antigen-binding fragment thereof that is capable of binding to the CD4 binding site on env protein of human immunodeficiency virus type 1 (HIV-1), comprising: (i) a heavy chain variable domain (VH) comprising a complementarity determining region (CDR)Hl, a CDRH2, and a CDRH3 comprising the amino acid sequences set forth in SEQ ID NOS: 19, 2, and 3, respectively; (ii) a light chain variable domain (VL) comprising a CDRL1 comprising the amino acid sequence of SEQ ID NO:4, a CDRL2 comprising the amino acid sequence of “TTS”, and a CDRL3 comprising the amino acid sequence of SEQ ID NO:21; and (iii) a Fc polypeptide or fragment thereof comprising substitution mutations, wherein the substitution mutations comprise: (a) G236A, Y300L, M428L and N434S; (b) M428L and N434S; (c) M252Y, S254T, and T256E; (d) G236A, Y300L, M252Y, S254T, and T256E; (e) G236A, A330L, I332E, M428L, and N434S; or (1) G236A, A330L, I332E, M252Y. S254T, T256E; wherein the amino acid residues are numbered according to the EU numbering system.

[0431] Embodiment 8. The antibody or antigen-binding fragment thereof of embodiment 7, wherein the VH comprises, consists essentially of, or consists of an amino acid sequence having at least 80%, 85%, 90%, 95%, 97%, or 99% identity to the amino acid sequence set

[0432] 81

[0433] 178476135.1 forth in SEQ ID NO:22, and / or the VL comprises, consists essentially of, or consists of an amino acid sequence having at least 80%, 85%, 90%, 95%, 97%, or 99% identity to amino acid sequence set forth in SEQ ID NO:23; or wherein the VH comprises, consists essentially of, or consists of the amino acid sequence set forth in SEQ ID NO:22, and / or the VL comprises or consists of the amino acid sequence set forth in SEQ ID NO:23.

[0434] Embodiment 9. An antibody or antigen-binding fragment thereof that is capable of binding to the CD4 binding site on env protein of human immunodeficiency virus type 1 (HIV-1), comprising: (i) a heavy chain variable domain (VH) comprising a complementarity determining region (CDR)H1, a CDRH2, and a CDRH3 comprising the amino acid sequences set forth in SEQ ID NOS:24-26, respectively; (ii) a light chain variable domain (VL) comprising a CDRL1 comprising the amino acid sequence of SEQ ID NO: 14, a CDRL2 comprising the amino acid sequence of ‘ DGS’’, and a CDRL3 comprising the amino acid sequence of SEQ ID NO: 16; and (iii) a Fc polypeptide or fragment thereof comprising substitution mutations, wherein the substitution mutations comprise: (a) G236A, Y300L, M428L and N434S; (b) M428L and N434S; (c) M252Y, S254T, and T256E; (d) G236A, Y300L, M252Y. S254T. and T256E; (e) G236A, A330L. I332E, M428L, and N434S; or (f) G236A, A330L, I332E, M252Y, S254T, T256E; wherein the amino acid residues are numbered according to the EU numbering system.

[0435] Embodiment 10. The antibody or antigen-binding fragment thereof of embodiment 9, wherein the VH comprises, consists essentially of, or consists of an amino acid sequence having at least 80%, 85%, 90%, 95%, 97%, or 99% identity to the amino acid sequence set forth in SEQ ID NO:27, and / or the VL comprises, consists essentially of, or consists of an amino acid sequence having at least 80%, 85%, 90%, 95%, 97%, or 99% identity to amino acid sequence set forth in SEQ ID NO:28; or wherein the VH comprises, consists essentially of, or consists of the amino acid sequence set forth in SEQ ID NO:27, and / or the VL comprises or consists of the amino acid sequence set forth in SEQ ID NO:28.

[0436] Embodiment 11. An antibody or antigen-binding fragment thereof that is capable of binding to the CD4 binding site on env protein of human immunodeficiency virus type 1 (HIV-1), comprising: (i) a heavy chain variable domain (VH) comprising a complementarity determining region (CDR)H1, a CDRH2, and a CDRH3 comprising the amino acid sequences set forth in SEQ ID NOS: 11, 29, and 30, respectively; (ii) a light chain variable domain (VL) comprising a CDRL1 comprising the amino acid sequence of SEQ ID NO: 14, a CDRL2 comprising the amino acid sequence of “DGS”, and a CDRL3 comprising the amino

[0437] 82

[0438] 178476135.1 acid sequence of SEQ ID NO: 15; and (iii) a Fc polypeptide or fragment thereof comprising substitution mutations, wherein the substitution mutations comprise: (a) G236A, Y300L. M428L and N434S; (b) M428L and N434S; (c) M252Y, S254T, and T256E; (d) G236A, Y300L, M252Y, S254T, and T256E; (e) G236A, A330L, I332E, M428L, and N434S; or (f) G236A, A330L, I332E, M252Y, S254T, T256E; wherein the amino acid residues are numbered according to the EU numbering system.

[0439] Embodiment 12. The antibody or antigen-binding fragment thereof of embodiment 11, wherein the VH comprises, consists essentially of, or consists of an amino acid sequence having at least 80%, 85%, 90%, 95%, 97%, or 99% identity to the amino acid sequence set forth in SEQ ID NO:31, and / or the VL comprises, consists essentially of, or consists of an amino acid sequence having at least 80%, 85%, 90%, 95%, 97%, or 99% identity to amino acid sequence set forth in SEQ ID NO: 32; or wherein the VH comprises, consists essentially of, or consists of the amino acid sequence set forth in SEQ ID NO:31, and / or the VL comprises or consists of the amino acid sequence set forth in SEQ ID NO:32.

[0440] Embodiment 13. The antibody or antigen-binding fragment thereof of any one of embodiments 1-12, wherein the Fc polypeptide or fragment thereof comprises substitution mutations G236A, Y300L, M428L and N434S.

[0441] Embodiment 14. The antibody or antigen-binding fragment thereof of any one of embodiments 1-12, wherein the Fc polypeptide or fragment thereof comprises substitution mutations M428L and N434S.

[0442] Embodiment 15. The antibody or antigen-binding fragment thereof of any one of embodiments 1-12, wherein the Fc polypeptide or fragment thereof comprises substitution mutations M252Y, S254T, and T256E.

[0443] Embodiment 16. The antibody or antigen-binding fragment thereof of any one of embodiments 1-12, wherein the Fc polypeptide or fragment thereof comprises substitution mutations G236A, Y300L, M252Y, S254T, and T256E.

[0444] Embodiment 17. The antibody or antigen-binding fragment thereof of any one of embodiments 1-16, wherein the antibody or antigen-binding fragment thereof comprises a CHI domain and / or a CL domain.

[0445] Embodiment 18. The antibody or antigen-binding fragment thereof of embodiment 17, wherein the CL domain is a kappa CL domain.

[0446] Embodiment 19. The antibody or antigen-binding fragment thereof of embodiment 17 or 18. wherein the CHI domain comprises the amino acid sequence set forth in SEQ ID

[0447] 83

[0448] 178476135.1 NO: 119 and / or the CL domain comprises the amino acid sequence set forth in SEQ ID

[0449] NO: 117 or 118.

[0450] Embodiment 20. The antibody or antigen-binding fragment thereof of any one of embodiments 1-19, wherein the antibody or antigen -binding fragment thereof comprises an IgG isotype.

[0451] Embodiment 21. The antibody or antigen-binding fragment thereof of embodiment 20, wherein the antibody or antigen-binding fragment thereof comprises an IgGl, IgG2, IgG3, or IgG4 isotype.

[0452] Embodiment 22. The antibody or antigen-binding fragment thereof of any one of embodiments 1-21, wherein the antibody or antigen-binding fragment is a human antibody.

[0453] Embodiment 23. The antibody or antigen-binding fragment thereof of any one of embodiments 1-22, wherein the antibody or antigen -binding fragment thereof comprises a monoclonal antibody.

[0454] Embodiment 24. The antibody or antigen-binding fragment thereof of any one of embodiments 1-23, wherein the antibody, or antigen-binding fragment thereof comprises a Glm3 allotype, a Glml7 allotype, a Glml allotype, or any combination thereof.

[0455] Embodiment 25. The antibody or antigen-binding fragment thereof of any one of embodiments 1-24, wherein the Fc polypeptide comprises, consists essentially of, or consists of the amino acid sequence having at least 80%. 85%. 90%. 91%. 92%. 93%, 94%, 95%, 96%. 97%. 98%. or 99% identity to the amino acid sequence set forth in any one of SEQ ID NOS: 76-79, 57, 64, 88-91, 100-103, and 112-115.

[0456] Embodiment 26. The antibody or antigen-binding fragment thereof of embodiment 25, wherein the Fc polypeptide comprises, consists essentially of, or consists of the amino acid sequence set forth in any one of SEQ ID NOS: 76-79, 57, 64, 88-91. 100-103. and 112- 115.

[0457] Embodiment 27. The antibody or antigen-binding fragment thereof of any one of embodiments 1-26, wherein the antibody or antigen-binding fragment thereof comprises: (i) a hinge-CH2-CH3 polypeptide comprising the amino acid sequence set forth in any one of SEQ ID NOS: 72-75, 56, 63, 84-87. 96-99, and 108-111; or (n) a CH1-CH3 polypeptide comprising the amino acid sequence set forth in any one of SEQ ID NOS: 43, 46-49, 52-55, 58-60, 62, 65, 66, 68-71, 80-83, 92-95, 104-107, and 120.

[0458] Embodiment 28. The antibody or antigen-binding fragment thereof of embodiments 1-3 and 13-27, wherein the antibody, or antigen-binding fragment thereof comprises: (i) a

[0459] 84

[0460] 178476135.1 heavy chain comprising an amino acid sequence having at least 80%, 85%, 90%, 91%, 92%, 93%, 94%. 95%. 96%. 97%. 98%. or 99% identity’ to the amino acid sequence set forth in SEQ ID NO:9; and / or (ii) a light chain comprising an amino acid sequence having at least 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence set forth in SEQ ID NO: 10.

[0461] Embodiment 29. The antibody or antigen-binding fragment thereof of any one of embodiments 1-3 and 13-27, wherein the antibody, or antigen-binding fragment thereof comprises: (i) a heavy chain comprising, consisting essentially of, or consisting of the amino acid sequence set forth in SEQ ID NO:9; and / or (ii) a light chain comprising, consisting essentially of, or consisting of the amino acid sequence set forth in SEQ ID NOTO.

[0462] Embodiment 30. The antibody or antigen-binding fragment of any one of embodiments 1-29, wherein the antibody or antigen -binding fragment is afucosylated; has been produced in a host cell that is incapable of fucosylation or that is inhibited in its ability to fucosylate a polypeptide; has been produced under conditions that inhibit fucosylation thereof by a host cell; or any combination thereof.

[0463] Embodiment 31. An antibody comprising a heavy chain (HC) and a light chain (LC), wherein the EIC and the LC comprise the amino acid sequences set forth in SEQ ID NO: 9 and SEQ ID NOTO, respectively, and wherein the antibody is afucosylated.

[0464] Embodiment 32. An isolated polynucleotide encoding the antibody or antigenbinding fragment of any one of embodiments 1 -31 , or encoding a VH, a heavy chain, a VL, and / or a light chain of the antibody or the antigen-binding fragment of any one of embodiments 1-31.

[0465] Embodiment 33. The polynucleotide of embodiment 32, wherein the polynucleotide comprises deoxyribonucleic acid (DNA) or ribonucleic acid (RNA), wherein the RNA optionally comprises messenger RNA (mRNA).

[0466] Embodiment 34. The polynucleotide of embodiment 32 or 33, wherein the polynucleotide is codon-optimized for expression in a host cell.

[0467] Embodiment 35. The polynucleotide of embodiment 34, wherein the host cell comprises a human cell or a CHO cell.

[0468] Embodiment 36. The polynucleotide of embodiment 34 or 35, wherein the host cell is a production host cell.

[0469] 85

[0470] 178476135.1 Embodiment 37. The polynucleotide of embodiment 35, wherein the host cell is an in vivo human host cell.

[0471] Embodiment 38. A recombinant vector comprising the polynucleotide of any one of embodiments 32-37.

[0472] Embodiment 39. A host cell comprising the polynucleotide of any one of embodiments 32-37, and / or the recombinant vector of embodiment 38, wherein the polynucleotide is optionally heterologous to the host cell and / or wherein the host cell is capable of expressing the encoded antibody or antigen-binding fragment or polypeptide.

[0473] Embodiment 40. An isolated human B cell comprising the polynucleotide of any one of embodiments 32-37, and / or the recombinant vector of embodiment 38, wherein polynucleotide is optionally heterologous to the human B cell and / or wherein the human B cell is immortalized.

[0474] Embodiment 41. A composition or combination comprising: (i) the antibody or antigen-binding fragment of any one of embodiments 1-31; (ii) the polynucleotide of any one of embodiments 32-37; (iii) the recombinant vector of embodiment 38; (iv) the host cell of embodiment 39; and / or (v) the human B cell of embodiment 40, and, optionally, a pharmaceutically acceptable excipient, carrier, or diluent.

[0475] Embodiment 42. A method of making an antibody or antigen-binding fragment of any one of embodiments 1-31, comprising culturing the host cell of embodiment 39 or the human B cell of embodiment 40 for a time and under conditions sufficient for the host cell or human B cell, respectively, to express the antibody or antigen-binding fragment.

[0476] Embodiment 43. The method of making an antibody or antigen-binding fragment of embodiment 42, wherein the host cell of embodiment 39 or the human B cell of embodiment 40 comprises the polynucleotide of any one of embodiment 32-37 and / or recombinant vector of embodiment 38.

[0477] Embodiment 44. The method of embodiment 42 or 43, further comprising isolating the antibody or antigen-binding fragment.

[0478] Embodiment 45. A method of treating or preventing EIIV-1 infection in a subject, the method comprising administering to the subject an effective amount of (i) the antibody or antigen-binding fragment of any one of embodiments 1-31; (ii) the polynucleotide of any one of embodiments 32-37; (iii) the recombinant vector of embodiment 38; (iv) the host cell of

[0479] 86

[0480] 178476135.1 embodiment 39; (v) the human B cell of embodiment 40; and / or (vi) the composition of embodiment 41.

[0481] Embodiment 46. The method of embodiment 45, comprising administering a single dose of the antibody or antigen-binding fragment, polynucleotide, recombinant vector, host cell, human B cell, or composition to the subject.

[0482] Embodiment 47. The method of embodiment 45 or 46, comprising administering two or more doses of the antibody or antigen-binding fragment, polypeptide, polynucleotide, recombinant vector, host cell, human B cell, or composition to the subject.

[0483] Embodiment 48. The method of any one of embodiments 45-47, wherein the antibody or antigen-binding fragment, polypeptide, polynucleotide, recombinant vector, host cell, human B cell, or composition is administered to the subject once even,' 6 months or longer.

[0484] Embodiment 49. The method of any one of embodiments 45-48, comprising administering the antibody or antigen-binding fragment, polynucleotide, recombinant vector, host cell, human B cell, or composition to the subject subcutaneously.

[0485] Embodiment 50. The method of any one of embodiments 45-48, comprising administering the antibody or antigen-binding fragment, polynucleotide, recombinant vector, host cell, human B cell, or composition to the subject intravenously.

[0486] Embodiment 51. The method of any one of embodiments 45-50, wherein the subject is HIV positive.

[0487] Embodiment 52. The method of any one of embodiments 36-51, wherein the subject has received, is receiving, or will receive anti-retroviral therapy.

[0488] Embodiment 53. The method of embodiment 52, wherein the anti-retroviral therapy comprises a nucleoside reverse transcriptase inhibitor, a non-nucleoside reverse transcriptase inhibitor, a protease inhibitor, a fusion inhibitor, a CCR5 antagonist, an integrase strand transfer inhibitor, an attachment inhibitor, a post-attachment inhibitor, a capsid inhibitor, a pharmacokinetic enhancer, an anti-HIV antibody, a combination antiretroviral therapy, or any combination thereof.

[0489] Embodiment 54. The method of embodiment 52 or 53, wherein the anti-retroviral therapy is a long-acting retroviral therapy.

[0490] 87

[0491] 178476135.1 Embodiment 55. The method of embodiment 54, wherein the long-acting retroviral therapy comprises cabotegravir, rilpivirine, and / or lenacapavir.

[0492] Embodiment 56. The method of embodiment 53, wherein: (a) the nucleoside reverse transcriptase inhibitor comprises abacavir, emtricitabine, lamivudine, tenofovir disoproxil fumarate, tenofovir alafenamide fumarate, zidovudine, or any combination thereof; (b) the non-nucleoside reverse transcriptase inhibitor comprises doravirme, efavirenz, etravinne, nevirapine, rilpivirine, or any combination thereof; (c) the protease inhibitor comprises atazanavir, darunavir, fosamprenavir, ritonavir, tipranavir, or any combination thereof; (d) the fusion inhibitor comprises enfuvirtide; (e) the CCR5 antagonist comprises maraviroc; (f) the integrase strand transfer inhibitor comprises cabotegravir, dolutegravir, raltegravir, bictegravir, or any combination thereof; (g) the attachment inhibitor comprises fostemsavir; (h) the post-attachment inhibitor comprises ibalizumab-uiyk; (i) the capsid inhibitor comprises lenacapavir; (j) the pharmacokinetic enhancer comprises cobicistat; (k) the antiHIV antibody comprises N6-LS antibody, 3BNC117-LS antibody, 10-1074-LS antibody, or VRC07-523-LS antibody; or (1) the combination antiretroviral therapy comprises Epzicom (abacavir and lamivudine); Triumeq (abacavir, dolutegravir, and lamivudine); Trizivir (abacavir, lamivudine, and zidovudine); Evotaz (atazanavir and cobicistat); Biktarvy (bictegravir, emtricitabine. and tenofovir alafenamide); Cabenuva (cabotegravir and rilpivirine); Prezcobix (darunavir and cobicistat); Symtuza (darunavir, cobicistat, emtricitabine, and tenofovir alafenamide); Dovato (dolutegravir and lamivudine); Juluca (dolutegravir and rilpivirine); Destrigo (doravirine, lamivudine, and tenofovir disoproxil fumarate); Symfi (efavirenz, lamivudine, and tenofovir disoproxil fumarate); Genvoya (elvitegravir, cobicistat, emtricitabine, and tenofovir alafenamide); Stribild (elvitegravir, cobicistat, emtricitabine, and tenofovir disoproxil fumarate); Odefsey (emtricitabine, rilpivirine,and tenofovir alafenamide); Complera (emtricitabine, rilpivirine, and tenofovir disoproxil fumarate); Descovy (emtricitabine and tenofovir alafenamide); Truvada (emtricitabine and tenofovir disoproxil fumarate); Cimduo (lamivudine and tenofovir disoproxil fumarate); or Kaletra (lopinavir and ritonavir).

[0493] Embodiment 57. The method of any one of embodiments 45-56, wherein the subject has a blood or plasma level of <50 copies / mL of HIV-RNA at 6 months following administration of a single dose of the antibody or antigen-binding fragment.

[0494] 88

[0495] 178476135.1 Embodiment 58. The method of any one of embodiments 45-57, wherein the subject has a blood or plasma level of <50 copies / mL of HIV-RNA at 12 months following administration of a single dose of the antibody or antigen-binding fragment.

[0496] Embodiment 59. The method of any one of embodiments 45-58, wherein the antibody or antigen-binding fragment thereof is administered intravenously to the subject at a dose from about 1 mg / kg (i.e., about 70 mg for a 70 kg subject) to about 120 mg / kg (i.e., about 8,400 mg for a 70 kg subject); about 2 mg / kg (i.e., about 140 mg for a 70 kg mammal) to about 115 mg / kg (i.e., about 8,050 mg for a 70 kg subject); about 2 mg / kg (i.e., about 140 mg for a 70 kg subject) to about 110 mg / kg (i.e., about 7,700 mg for a 70 kg subject); about 2 mg / kg (i.e., about 140 mg for a 70 kg subject) to about 50 mg / kg (i.e., about 3,500 mg for a 70 kg subject); about 2 mg / kg (i.e., about 140 mg for a 70 kg subject) to about 45 mg / kg (i.e., about 3,150 mg for a 70 kg subject); about 5 mg / kg (i.e., about 350 mg for a 70 subject) to about 115 mg / kg (i.e., about 8,050 mg for a 70 kg subject); or about 5 mg / kg (i.e., about 350 mg for a 70 kg subject) to about 110 mg / kg (i.e., about 7,700 mg for a 70 kg subject).

[0497] Embodiment 60. The method of any one of embodiments 45-59, wherein the antibody or antigen-binding fragment thereof is administered intravenously to the subject at a dose of about 100 mg, 200 mg, 300 mg, 400 mg, 500 mg, 600 mg, 700 mg, 800 mg, 900 mg, 1000 mg. 1100 mg, 1200 mg, 1300 mg, 1400 mg, 1500 mg. 1600 mg, 1700 mg, 1800 mg,

[0498] 1900 mg, 2000 mg, 2250 mg, 2500 mg, 2750 mg, 3000 mg, 3250 mg, 3500 mg , 3750 mg,

[0499] 4000 mg, 4250 mg, 4500 mg, 4750 mg, 5000 mg, 5250 mg, 5500 mg, 5750 mg, 6000 mg,

[0500] 6250 mg. 6500 mg, 6750 mg, 7000 mg, 7250 mg, 7500 mg. 7750 mg, 8000 mg, 8250 mg,

[0501] 8500 mg. 8750 mg, 9000 mg, 9250 mg, 9500 mg, 9750 mg. 10000 mg, 11000 mg, 12000 mg, 13000 mg, 14000 mg, 15000 mg, 16000 mg, 17000 mg, 18000 mg, 19000 mg, 20000 mg, 22500 mg, or 25000 mg.

[0502] Embodiment 61. The antibody or antigen-binding fragment of any one of embodiments 1-31, the polynucleotide of any one of embodiments 32-37, the recombinant vector of embodiment 38, the host cell of embodiment 39, the human B cell of embodiment 40. and / or the composition of embodiment 41, for use in a method of treating or preventing HIV-1 infection in a subject.

[0503] Embodiment 62. The antibody or antigen-binding fragment of any one of embodiments 1-31, the polynucleotide of any one of embodiments 32-37, the recombinant

[0504] 89

[0505] 178476135.1 vector of embodiment 38, the host cell of embodiment 39, the human B cell of embodiment 40, and / or the composition of embodiment 41, for use in the preparation of a medicament for treating or preventing HIV-1 infection in a subject.

[0506] EXAMPLES EXAMPLE 1

[0507] A06 ANTIBODY HAS BROAD AND POTENT NEUTRALIZING ACTIVITY

[0508] Antibody “A06” was isolated from an HIV-1 infected individual who was previously identified as having exceptional serum neutralizing activity against HIV-1 in in vitro assays. Antibody A06 is an IgGl monoclonal antibody having a VH amino acid sequence according to SEQ ID NO:7 and a VL amino acid sequence according to SEQ ID NO:8.

[0509] To determine the overall neutralizing potency and breadth, A06 antibody as well as other antibodies were tested for neutralizing activity in the TZM-bl cell neutralization assay (Sarzotti-Kelsoe et al., J Immunol Methods. 2014 Jul; 409: 131-46; Seaman et al., J Virol. 2010 Feb;84(3): 1439-52) against a reference panel of 12 HIV-1 pseudovirus strains that is referred to as “global panel” (Figure 1A). This panel of pseudoviruses was previously designed to be a representation of the diversity of the global HIV-1 epidemic and enable a standardized assessment of the activity of neutralizing antibodies. A06 antibody was compared with N6 antibody and 3BNC117 antibody, which are also HIV-1 env CD4 binding site antibody that are currently in clinical testing. A06 antibody neutralizes 100% (12 / 12) strains of the “global panel” and displays a high level of potency as measured by geometric mean IC50.

[0510] A06 antibody was tested against an extended panel of 99 HIV-1 pseudoviruses, which provides a representation of the genetic and global diversity of HIV-1 Env variants. It includes HIV-1 variants of different clades or subtypes, including variants isolated from transmi tted / founder viruses and difficult-to-neutralize viruses. A06 antibody demonstrated high neutralizing potency and breadth when tested on the 99 pseudovirus multicade panel (Figure IB). A06 antibody neutralized 99% of the tested pseudoviruses and exhibited a geometric mean IC50 of 0.036 pg / ml against the neutralized pseudoviruses. A06 breadth and potency were equivalent or superior to N6 and 3BNC117 antibodies that also target the CD4 binding site.

[0511] A06 antibody was tested against a published reference clade C panel that consists of 100 HIV-1 pseudo viruses isolated from different stages of infection and difficult-to-neutralize

[0512] 90

[0513] 178476135.1 viruses. The clade C panel is described in Hraber et al., J Virol., 2017 Sep 12;91(19):e00991- 17. A06 antibody demonstrated high neutralizing potency and breadth when tested against the Clade C panel (Figure 1C). A06 antibody neutralized 99% of the tested pseudoviruses and showed a geometric mean ICso of 0.057 pg / ml against the neutralized pseudoviruses.

[0514] Antibody Mediated Prevention (AMP) Trials showed that A06 antibody neutralized up to 98% of 185 pseudovirus strains (Figure ID) generated from the virus sequences obtained from the AMP trials (as described in Corey L, Two Randomized Trials of Neutralizing Antibodies to Prevent HIV-1 Acquisition. N Engl J Med. 2021 Mar 18;384(11): 1003-1014). A06 antibody exhibited a GeoMean ICso (0.084 pg / ml) against the virus panel.

[0515] Additional neutralization activity against multiple clades for A06 antibody is shown in Figure 2A and against a virus panel (100) for A06 antibody is shown in Figure 2B, including breadth and geometric mean ICso, as compared to N6 and 3BNC117 antibodies, which both target CD4 binding site of HIV env.

[0516] A06 antibody has broad and potent neutralizing activity against hundreds of pseudoviruses, has equivalent or superior breadth and potency compared to clinical stage antibodies that target the CD4 binding site of HIV- 1 env, and has broad and potent neutralizing activity against currently circulating viruses.

[0517] The neutralization activity of 04_A06 antibody against replication-competent donor derived outgrowth viruses, which are more challenging to neutralize than pseudoviruses (Cohen, Y. Z. et al. Neutralizing Activity of Broadly Neutralizing Anti-HIV-1 Antibodies against Clade B Clinical Isolates Produced in Peripheral Blood Mononuclear Cells. J. Virol. 682 92, eO 1883- 17 (2018)). Replication-competent donor derived outgrowth viruses were obtained by isolating CD4+ T cells from the peripheral blood mononuclear cells of people living with HIV and culturing these cells in the presence of irradiated PBMCs from healthy donors. Once HIV was detected by the presence of p24, the supernatants were harvested, frozen and used in neutralization assays. Against these replication-competent HIV viruses, 04_A06 demonstrated substantial breadth and potency (GeoMean IC50 / IC80=0.45 / 1.736 pg / ml, Breadth=94% / 88%) comparable or greater than all of the tested reference antibodies (FIG. 2C)

[0518] 91

[0519] 178476135.1 EXAMPLE 2

[0520] A06 ANTIBODY SUPPRESSES LIVE VIRUSES IN VIVO MODEL OF HIV-1 INFECTION

[0521] Humanized mice infected with replication competent, recombinant HIV-1YU2 (Zhang et al., 2002, J. Virol. 76:6332-43) provide a model to study the antiviral activity of neutralizing HIV-1 antibodies in vivo. To generate humanized mice, immunodeficient NRG mice are irradiated within the first days after birth and injected intrahepatically with human hematopoietic CD34+stem cells. This results in the development of human lymphocytes that can be infected with replication-competent HIV-1. These mice can maintain stable levels of viremia (i.e. , HIV-1 RNA copy numbers in plasma) and show a rate of HIV- 1 sequence diversification that is similar to what is observed in humans (Klein et al., Nature. 2012 Dec 6; 492(7427): 118-22. doi: 10. 1038 / naturel 1604). Mice were treated with A06 antibody or control antibodies that also bind the CD4 binding site of HIV-1 env (VRC01 or VRC07 antibodies). For VRC01 and VR07 antibodies, only a transient reduction of the HIV-1 RNA copy number was observed, and viremia returned to baseline levels in most mice within 2-4 weeks (Figure 3). A06 antibody viral suppression was observed in all treated mice for a period of 84 days of treatment (Figure 3). In all mice (100%), the HIV-1 RNA plasma copy number was reduced to levels below the limit of accuracy of the used assay. No escape virus was detected at high viral load or at A06 antibody washout. Thus, A06 antibody is capable to effectively induce and maintain viral suppression in HIV-lvu2-infected humanized mice even when given as monotherapy.

[0522] Failure of antibody monotherapy using CD4 binding site antibodies in HIV- 1 -infected humanized mice results in viral rebound and is associated with viral resistance against the administered antibody (Freund et al., 2015, PLoS Pathog. H:el005238; Horwitz et al, 2013, Proc. Natl. Acad. Sci. USA 110: 16538-16543; Klein et al, 2012, supra, Freund et al., 2017, Sci Transl Med. 9, eaal2144).

[0523] HIV-lyu2-infected humanized mice treated with CD4 binding site antibody VRC01 showed a transient reduction of viremia, which returned to baseline levels in most mice within 2-4 weeks (Figure 4A). Addition of A06 antibody to the treatment regimen at four weeks following the viral rebound resulted in sustained reduction of viremia in all mice (Figure 4A). Compared to another CD4 binding site antibody in advanced stage of clinical testing (VRC01), A06 antibody has a strong resistance profile and suppresses VRC01 escape virus in vivo.

[0524] Antibody-resistant HIV-1 variants exist. Neutralization profile of A06 antibody was

[0525] 92

[0526] 178476135.1 determined against a panel of resistant pseudoviruses. Compared with other CD4 binding site antibodies (N6 and 3BNC117), A06 antibody neutralizes resistant variants with much higher breadth and / or potency (Figure 4B).

[0527] EXAMPLE 3 CHARACTERIZATION OF FC MODIFIED A06 ANTIBODY

[0528] Modifications to Fc of the parent A06 antibody were made in change interaction FcyRs and increase the antibody half-life. A06-LS antibody is the parent A06 antibody with M428L / N434S (LS) amino acid substitutions. A06-LS-GAYL-afuc antibody is afucosylated A06 antibody with M428L / N434S (LS) and G236A / Y300L amino acid substitutions (GAYL). A06-LS-GAALIE antibody is A06 antibody with M428L / N434S and G236A / A330L / I332E amino acid substitutions. A06-LS-GRLR antibody is A06 antibody with M428L / N434S and G236R / L328R amino acid substitutions (used a negative control for effector function assays).

[0529] Fc modifications to A06 antibody were tested for antibody dependent cell killing (Figure 5). To test antibody-dependent cellular cy totoxicity' (ADCC), human NK cells isolated from PBMC were mixed with A06 antibodies with differing Fc mutations and target CHO cells expressing the HIV envelope protein. A06-LS-GAYL-Afuc antibody and A06-LS- GAALIE antibody show improved ADCC effector function compared to A06-LS antibody.

[0530] Fc modified A06 antibodies were also tested for FcyR signaling (FcyRIIIa-V, FcyRIIIa-F, and FcyRIIa-H) (Figure 7A). Jurkat FcyR signaling reporter cells were mixed ith Fc-modified A06 antibodies and target CHO cells expressing the HIV envelope protein. A06-LS-GAYL-afuc antibody showed strong FcyR signaling compared to either A06-LS- GAALIE and parent A06-LS (Figure 7B). In addition, Jurkat FcyR signaling reporter cells were mixed with Fc-modified A06 antibodies and primary' human CD4 T cells infected with HIV as the target cells. A06-LS-GAYL-afuc antibody showed improved FcyR signaling in response to HIV-infected target cells consistent with robust effector function properties (Figure 7C). A06-LS, A06-LS-GAALIE, A06-LS-GRLR, and A06-LS-GAYL-afuc antibodies were tested for binding affinity to FcyRIIa (CD32a), FcyRIIb (CD32b), and FcyRIIIa (CD16a). A06 Fc variant antibodies show changes in FcyR binding consistent with historical data of other monoclonal antibodies of the same Fc variant. A06-LS-GAALIE, and A06-LS-GAYL-afuc show' increased FcyRIIIa binding; A06-LS-GAYL-afuc shows greater fold increase in FcyRIIa binding than A06-LS-GAALIE (Figure 7D).

[0531] 93

[0532] 178476135.1 A06-LS antibody, A06-LS-GAYL-afuc antibody, A06-LS-GAALIE antibody, and A06-LS-GRLR antibodies were tested for target cell killing, and phagocytosis, antigen presentation, and T cell activation (Figures 8A-8C). Fc modifications to A06 antibody were tested for ADCC using human NK cells with specific FcyRIIIa genotypes (Figure 8A). A06- LS-GAYL-Afuc antibody showed improved ADCC effector function irrespective of FcyRIIIa genotype. Next, total human PBMCs were used as effector cells to kill target CHO cells expressing HIV envelope protein (Figure 8B). Primary human CD14+monocytes were isolated from healthy PBMC with GM-CSF (100 ng / mL) and IL-4 (100 ng / mL). On day 6, immature monocyte derived dendritic cells (moDCs) were harvested and used to assess phagocytosis. CHO-HIV JRFL ENV target cells were labeled with pHrodo red dye solution, washed, and mixed with moDCs. HIV bnAbs were added to target cells, prior to addition of effector cells at 10:1 E:T ratio. Samples for ADCP were imaged on an Incucyte imager. Alternately samples were collected following overnight incubation, stained with anti-CD83, anti-CD86, and anti-HLA-DR antibodies, and analy zed by flow cytometry to assess moDC activation. Cryopreserved PBMCs from HIV positive donors were thawed, washed, and stained with CellTrace Violet (CTV) dye. CTV labeled samples were washed mixed with CHO-HIV JRFL ENV target cells pretreated with various HIV bnAbs. Following 5 days coculture, samples were stained with anti-CD3, anti-CD8, anti-CD25 antibodies and analyzed by flow cytometry to assess the proliferation and activation of CD8+ T cells. PBMCs from either healthy subjects or PBMCs from people living with HIV (PLWH) were tested as effector cells. A06-LS-GAYL-Afuc antibody showed improved HIV envelope expressing target cell killing using PBMC from PLWH. Next, A06 Fc modified antibodies were tested in a series of effector functions to phagocytosis, antigen presentation, and T cell activation (Figure 8C). The antibody dependent cellular phagocytosis (ADCP) assay and moDC activation assays both used monocyte-derived dendritic cells (moDCs) as effector cells and CHO cells expressing HIV envelope protein as target cells. A06-LS-GAYL-Afuc antibody showed the strongest phagocytic activity in the ADCP assay and the greatest activation of moDCs as measured by upregulation of the cell surface molecule CD83. After phagocytosis of antigen, moDCs can present antigen to stimulate T cell responses. To test the ability of A06-LS-GAYL-Afuc antibody to increase the ability of moDCs to stimulate T cell responses, the activation and proliferation of CD8 T cells from PLWH, mixed with moDCs, CHO cells expressing HIV envelope protein, and A06 Fc modified antibodies was tested. A06-LS- GAYL-Afuc antibody showed the strongest induction of CD8 T cell activation and

[0533] 94

[0534] 178476135.1 proliferation. Overall, A06-LS-GAYL-afuc antibody showed strong effector function properties in all assays tested. A06-LS-GAYL-afuc antibody performs as well or better than A06-LS-GAALIE antibody in the in vitro effector function assays.

[0535] Effector functions for A06 antibody and a comparator N49 “tool” antibody, that also targets the CD4 binding site of HIV-1 env, were evaluated as wildtype Fc polypeptide, “LS- GAYL-afuc” modified Fc, and “LS-GRLR” modified Fc (Figure 9). Overall. LS-GAYL-afuc showed increased effector functions compared to wildtype Fc in the context of the N49 tool antibody, showing that the increased effector function of the LS-GAYL-afuc modification for HIV antibodies is not limited to the A06 antibody.

[0536] A06-LS-GAYL-Afuc antibody was tested against parent A06-LS antibody for in vitro pseudovirus neutralization. HIV envelope pseudotyped viruses were generate using 293T cells and neutralization measured using TZM-bl target cells. Two pseudovirus panels were used for testing. First, a global panel of pseudoviruses, which represents the diversity of envelopes across HIV clades. Second, a panel of pseudoviruses selected from the AMP study (AMP mini-panel of pseudoviruses) (Figure 6A). The AMP mini-panel strains were specifically selected for less sensitivity to A06 antibody. The A06-LS parent antibody and A06-LS-GAYL-Afuc antibody were also tested for in vitro neutralization against a panel of HIV clinical strains, focused on Clade B (Figure 6A). These data confirm that the breadth and potency determined for the parent A06-LS antibody on -400 pseudo viruses is similar for A06-LS-GAYL-Afuc antibody. Thus, the Fc modification to A06-LS-GAYL-Afuc antibody does not compromise the neutralization profile of A06 parent antibody. A06-LS-GAYL-afuc antibody showed exceptional neutralization against HIV isolates from patients compared to reference clinical stage anti-CD4 binding site broad neutralizing antibodies (bnAbs) N6 and 3BNC117 (Figures 6B, 6C). showing that Fc modification does not compromise the neutralization profile of the parent A06 mAb. The Fc modification to A06-LS-GAYL-Afuc antibody also does not compromise binding activity to gpl20 compared to the A06 parent antibody (Figure 6D). IC50, ICso, and IC90 values for A06 parent antibody and A06-LS- GAYL antibody determining using neutralization assays with a panel of live HIV virus isolates or a panel of pseudoviruses are provided in Table 5A. IC50 values of A06-LS-GAYL antibody compared with other broad neutralizing antibodies targeting the CD4 binding site are provided in Table 5B.

[0537] 95

[0538] 178476135.1 TABLE 5A. Inhibitory concentration for A06 antibody and A06-LS-GAYL antibody

[0539] TABLE 5B. IC50 concentration for A06-LS-GAYL antibody, N6 antibody, and 3BNC117 antibody

[0540] Initial PK assessment of A06-rIgGlml7,l-LS antibody and A06-rIgGlml7,l-LS- GAYL-afuc antibody were measured in 2 month old Tg32 SCID mice (n=5) following single dose intravenous administration of 5mg / kg (Figure 10). Sotrovimab was used as a control antibody. MSD quantification (anti-LS / anti-CH2) and NCA analysis (terminal elimination 7- 63 d) were performed. PK of the antibodies were within normal IgGl range. A06- rIgGlml7,l-LS-GAYL-afuc antibody had a PK of 11.7 days. GAYL-afucosylation modifications do not impact PK of the antibody, and the PK is similar to sotrovimab in Tg32 SCID mice (Table 5C).

[0541] TABLE 5C. PK Data in Tg32 SCID Mice

[0542] 96

[0543] 178476135.1 EXAMPLE 4 A06-RIGG1M17,1-LS-GAYL-AFUC PK STUDY IN MICE AND PREDICTED HUMAN PK

[0544] Non-human primate PK study was positive for anti-drug antibody (ADA) response, resulting in limited ability to estimate and report key PK parameters used for allometric scaling. As an alternative, Tg32 SCID mice PK data was obtained and leveraged for allometric scaling. Tg32 SCID mice (n=5) were administered a single intravenous dose of 5 mg / kg A06-LS-GAYL-afuc antibody and serum sampling continued for 63 days (Figure 11, left). The PK of A06-LS-GAYL-afuc antibody in Tg32 SCID mice was fit to a two- compartment PK model. The terminal elimination half-life (T1 / 2) in Tg32 SCID mice is approximately 12 days. Human PK parameters were scaled from Tg32 mice using an allometric scaling approach for human IgGs containing half-life extending LS modifications (Figure 11, right). The allometric coefficients of 0.78 for clearance and 0.95 volume of distribution, were estimated from internal LS-modified mAb platform. The predicted human clearance (CL) of A06-LS-GAYL-afuc is approximately 0.114 L / day, and the predicted volume of distribution (V) is approximately 8.9 L assuming human weight of 70 kg. The projected human terminal elimination half-life (T1 / 2) is approximately 54 days.

[0545] Estimated intravenous doses to maintain serum concentrations > 2 pg / mL, 10 pg / mL, 20 pg / mL, and 40 pg / mL for 4 months or 6 months in 90% of patient population were calculated (Figures 12A-12B).

[0546] EXAMPLE 5

[0547] An in vitro live virus suppression assay was performed using primary' human CD4+ T cells to measure the effect of the combination of neutralization and effector functions in tested antibodies. (Figure 13). A06-LS-GAYL-afuc antibody demonstrated enhancement of PBMC-mediated inhibition of p24+ target CD4+ T cells compared to A06-LS-GRLR antibody, showing that GAYL-afuc Fc-medicated effector functions contribute to HIV suppression.

[0548] EXAMPLE 6 A06-LS-GAYL-AFUC ANTIBODY SUPPRESSES HIV INFECTION IN VIVO

[0549] Immunodeficient NXG mice irradiated within the first days after birth and injected intrahepatically with human hematopoietic CD34+stem cells (CD34+ HSCs) were used as a

[0550] 97

[0551] 178476135.1 humanized mouse model of HIV infection. These mice develop human lymphocytes that can be infected with replication-competent HIV-1. Humanized NXG mice with humanized immune system (HIS) infected with replication competent HIV-1YU2 were treated with 1 mg / week A06-LS-GAYL-afuc antibody, A06-LS-GRLR antibody, or S2E12 antibody (negative control) for 8 weeks starting at 4 weeks post-infection (see schematic in Figure 14). HIV suppression was determined by measuring HIV-RNA levels. Results showed that Fc effector function enhanced A06-LS-GAYL-afuc antibody demonstrated a strong anti-viral effect with no viral escape, suppressing viral load below detectable limits in all animals by day 56, and A06-LS-GAYL-afuc antibody is more potent in vivo compared to effector function null A06-LS-GRLR antibody (Figure 14). A06-LS-GAYL-afuc antibody showed increased anti-viral effect by initial viral load drop and number of animals suppressing virus at 56 days. Thus, both neutralization and effector function contribute to anti-viral effect.

[0552] Effector function enhanced A06-LS-GAYL-afuc antibody has enhanced anti-viral activity in vivo compared to effector function normal (A06) / null Fc variant (A06-LS-GRLR) (Figure 15). Fc-enhanced A06-LS-GAYL-afuc antibody drives earlier achievement of undetectable virus in mouse model of HIV infection compared to A06 antibody with wildtype Fc.

[0553] The various embodiments described above can be combined to provide further embodiments. All of the U.S. patents. U.S. patent application publications. U.S. patent applications, foreign patents, foreign patent applications and non-patent publications referred to in this specification and / or listed in the Request, including U.S. Provisional Application No. 63 / 726,179 filed on November 27, 2024, and U.S. Provisional Application No. 63 / 807,217 filed on May 16. 2025, are incorporated herein by reference, in their entirety. Aspects of the embodiments can be modified, if necessary to employ concepts of the various patents, applications and publications to provide yet further embodiments.

[0554] These and other changes can be made to the embodiments in light of the abovedetailed description. In general, in the following claims, the terms used should not be construed to limit the claims to the specific embodiments disclosed in the specification and the claims, but should be construed to include all possible embodiments along with the full scope of equivalents to which such claims are entitled. Accordingly, the claims are not limited by the disclosure.

[0555] 98

[0556] 178476135.1

Claims

CLAIMSWhat is claimed is:

1. An antibody or antigen-binding fragment thereof that is capable of binding to the CD4 binding site on env protein of human immunodeficiency virus type 1 (HIV-1), comprising:(i) a heavy chain variable domain (VH) comprising a complementarity determining region (CDR)H1, a CDRH2, and a CDRH3 comprising the amino acid sequences set forth in SEQ ID NOS: 1-3, respectively;(ii) a light chain variable domain (VL) comprising a CDRL1 comprising the amino acid sequence of SEQ ID NO:4, a CDRL2 comprising the amino acid sequence of Thr- Ala-His (TAH), and a CDRL3 comprising the amino acid sequence of SEQ ID NO: 6 or SEQ ID NO:121; and(iii) a Fc polypeptide or fragment thereof comprising substitution mutations, wherein the substitution mutations comprise:(a) G236A. Y300L, M428L and N434S;(b) M428L and N434S;(c) M252Y, S254T, and T256E;(d) G236A, Y300L, M252Y, S254T, and T256E;(e) G236A, A330L. I332E, M428L, and N434S; or(f) G236A, A330L, I332E, M252Y S254T, T256E; wherein the amino acid residues are numbered according to the EU numbering system.

2. The antibody or antigen-binding fragment thereof of claim 1 , wherein the VH comprises, consists essentially of, or consists of an amino acid sequence having at least 80%, 85%, 90%, 95%, 97%, or 99% identity to the amino acid sequence set forth in SEQ ID NO:7, and / or the VL comprises, consists essentially of, or consists of an amino acid sequence having at least 80%, 85%, 90%, 95%, 97%, or 99% identity to amino acid sequence set forth in SEQ ID NO: 8.99178476135.

13. The antibody or antigen-binding fragment thereof of claim 1 or 2, wherein the VH comprises, consists essentially of, or consists of the amino acid sequence set forth in SEQ ID NO:7, and / or the VL comprises or consists of the amino acid sequence set forth in SEQ ID NO:8.

4. The antibody or antigen-binding fragment thereof of any one of claims 1-3, wherein the Fc polypeptide or fragment thereof comprises substitution mutations G236A, Y300L, M428L and N434S.

5. The antibody or antigen-binding fragment thereof of any one of claims 1-3, wherein the Fc polypeptide or fragment thereof comprises substitution mutations M428L and N434S.

6. The antibody or antigen-binding fragment thereof of any one of claims 1-3, wherein the Fc polypeptide or fragment thereof comprises substitution mutations M252Y, S254T. and T256E.

7. The antibody or antigen-binding fragment thereof of any one of claims 1-3, wherein the Fc polypeptide or fragment thereof comprises substitution mutations G236A, Y300L, M252Y, S254T, and T256E.

8. The antibody or antigen-binding fragment thereof of any one of claims 1-7, wherein the antibody or antigen-binding fragment thereof comprises a CHI domain and / or a CL domain.

9. The antibody or antigen-binding fragment thereof of claim 8, wherein the CL domain is a kappa CL domain.

10. The antibody or antigen-binding fragment thereof of claim 8 or 9, w herein the CHI domain comprises the amino acid sequence set forth in SEQ ID NO: 119 and / or the CL domain comprises the amino acid sequence set forth in SEQ ID NO: 117 or 118.100178476135.

111. The antibody or antigen-binding fragment thereof of any one of claims 1-10, wherein the antibody or antigen-binding fragment thereof comprises an IgG isotype.

12. The antibody or antigen-binding fragment thereof of claim 11, wherein the antibody or antigen-binding fragment thereof comprises an IgGl, IgG2, IgG3, or IgG4 isotype.

13. The antibody or antigen-binding fragment thereof of any one of claims 1-12, wherein the antibody or antigen-binding fragment is a human antibody.

14. The antibody or antigen-binding fragment thereof of any one of claims 1-13, wherein the antibody or antigen-binding fragment thereof comprises a monoclonal antibody.

15. The antibody or antigen-binding fragment thereof of any one of claims 1-14, wherein the antibody, or antigen-binding fragment thereof comprises a Glm3 allotype, a Glml7 allotype, a Glml allotype, or any combination thereof.

16. The antibody or antigen-binding fragment thereof of any one of claims 1-15, wherein the Fc polypeptide comprises, consists essentially of. or consists of the amino acid sequence having at least 80%, 85%, 90%, 91%, 92%, 93%, 94%. 95%, 96%. 97%. 98%. or 99% identity to the amino acid sequence set forth in any one of SEQ ID NOS: 76-79, 57, 64, 88-91, 100-103, and 112-115.

17. The antibody or antigen-binding fragment thereof of claim 16, wherein the Fc polypeptide comprises, consists essentially of, or consists of the amino acid sequence set forth in any one of SEQ ID NOS: 76-79, 57, 64, 88-91, 100-103, and 112-115.

18. The antibody or antigen-binding fragment thereof of any one of claims 1-17, wherein the antibody or antigen-binding fragment thereof comprises:(i) a hinge-CH2-CH3 polypeptide comprising the amino acid sequence set forth in any one of SEQ ID NOS: 72-75, 56, 63, 84-87, 96-99, and 108-111; or101178476135.1(ii) a CH1-CH3 polypeptide comprising the amino acid sequence set forth in any one of SEQ ID NOS: 43, 46-49, 52-55, 58-60.

62.

65. 66, 68-71, 80-83, 92-95, 104-107, and 120.

19. The antibody or antigen-binding fragment thereof of claims 1-18, wherein the antibody, or antigen-binding fragment thereof comprises:(i) a heavy chain comprising an amino acid sequence having at least 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence set forth in SEQ ID NO:9; and / or(ii) a light chain comprising an amino acid sequence having at least 80%, 85%, 90%. 91%. 92%. 93%. 94%. 95%. 96%. 97%. 98%. or 99% identity to the amino acid sequence set forth in SEQ ID NOTO.

20. The antibody or antigen-binding fragment thereof of any one of claims 1-19, wherein the antibody, or antigen-binding fragment thereof comprises:(i) a heavy chain comprising, consisting essentially of, or consisting of the amino acid sequence set forth in SEQ ID NO:9; and / or(ii) a light chain comprising, consisting essentially of, or consisting of the amino acid sequence set forth in SEQ ID NOTO.21 . The antibody or antigen-binding fragment of any one of claims 1-20, wherein the antibody or antigen-binding fragment is afucosylated; has been produced in a host cell that is incapable of fucosylation or that is inhibited in its ability to fucosylate a polypeptide; has been produced under conditions that inhibit fucosylation thereof by a host cell; or any combination thereof.

22. An antibody comprising a heavy chain (HC) and a light chain (LC), wherein the HC and the LC comprise the amino acid sequences set forth in SEQ ID NO: 9 and SEQ ID NOTO, respectively, and wherein the antibody is afucosylated.

23. An isolated polynucleotide encoding the antibody or antigen-binding fragment of any one of claims 1 -22, or encoding a VH, a heavy chain, a VL, and / or a light chain of the antibody or the antigen-binding fragment of any one of claims 1-22.102178476135.

124. The polynucleotide of claim 23, wherein the polynucleotide comprises deoxyribonucleic acid (DNA) or ribonucleic acid (RNA), wherein the RNA optionally comprises messenger RNA (mRNA).

25. The polynucleotide of claim 23 or 24, wherein the polynucleotide is codon- optimized for expression in a host cell.

26. The polynucleotide of claim 25, wherein the host cell comprises a human cell or a CHO cell.

27. The polynucleotide of claim 25, wherein the host cell is a production host cell.

28. The polynucleotide of claim 25, wherein the host cell is an in vivo human host cell.

29. A recombinant vector comprising the polynucleotide of any one of claims 23- 28.

30. A host cell comprising the polynucleotide of any one of claims 23-28, and / or the recombinant vector of claim 29, wherein the polynucleotide is optionally heterologous to the host cell and / or wherein the host cell is capable of expressing the encoded antibody or antigen-binding fragment or polypeptide.

31. An isolated human B cell comprising the polynucleotide of any one of claims 23-28, and / or the recombinant vector of claim 26. wherein polynucleotide is optionally heterologous to the human B cell and / or wherein the human B cell is immortalized.

32. A composition or combination comprising:(i) the antibody or antigen-binding fragment of any one of claims 1-22;(ii) the polynucleotide of any one of claims 23-28;(iii) the recombinant vector of claim 29;103178476135.1(iv) the host cell of claim 30; and / or(v) the human B cell of claim 31, and, optionally, a pharmaceutically acceptable excipient, carrier, or diluent.

33. A method of making an antibody or antigen-binding fragment of any one of claims 1-22, comprising culturing the host cell of claim 30 or the human B cell of claim 31 for a time and under conditions sufficient for the host cell or human B cell, respectively, to express the antibody or antigen-binding fragment.

34. The method of making an antibody or antigen-binding fragment of claim 33, wherein the host cell of claim 30 or the human B cell of claim 31 comprises the polynucleotide of any one of claim 23-28 and / or recombinant vector of claim 29.

35. The method of claim 33 or 34, further comprising isolating the antibody or antigen-binding fragment.

36. A method of treating or preventing HIV-1 infection in a subject, the method comprising administering to the subject an effective amount of(i) the antibody or antigen-binding fragment of any one of claims 1-22;(ii) the polynucleotide of any one of claims 23-28;(iii) the recombinant vector of claim 29;(iv) the host cell of claim 30;(v) the human B cell of claim 31 ; and / or(vi) the composition of claim 32.

37. The method of claim 36, comprising administering a single dose of the antibody or antigen-binding fragment, polynucleotide, recombinant vector, host cell, human B cell, or composition to the subject.104178476135.

138. The method of claim 36 or 37, comprising administering two or more doses of the antibody or antigen-binding fragment, polypeptide, polynucleotide, recombinant vector, host cell, human B cell, or composition to the subject.

39. The method of any one of claims 36-38, wherein the antibody or antigenbinding fragment, polypeptide, polynucleotide, recombinant vector, host cell, human B cell, or composition is administered to the subject once every 6 months or longer.

40. The method of any one of claims 36-39, comprising administering the antibody or antigen-binding fragment, polynucleotide, recombinant vector, host cell, human B cell, or composition to the subject subcutaneously.

41. The method of any one of claims 36-39, comprising administering the antibody or antigen-binding fragment, polynucleotide, recombinant vector, host cell, human B cell, or composition to the subject intravenously.

42. The method of any one of claims 36-41, wherein the subject is HIV positive.

43. The method of any one of claims 36-42, wherein the subject has received, is receiving, or will receive anti-retroviral therapy.

44. The method of claim 43, wherein the anti-retroviral therapy comprises a nucleoside reverse transcriptase inhibitor, a non-nucleoside reverse transcriptase inhibitor, a protease inhibitor, a fusion inhibitor, a CCR5 antagonist, an integrase strand transfer inhibitor, an attachment inhibitor, a post-attachment inhibitor, a capsid inhibitor, a pharmacokinetic enhancer, an anti-HIV antibody, a combination antiretroviral therapy, or any combination thereof.

45. The method of claim 43 or 44, wherein the anti-retroviral therapy is a long- acting retroviral therapy.105178476135.

146. The method of claim 45, wherein the long-acting retroviral therapy comprises cabotegravir. rilpivirine, and / or lenacapavir.

47. The method of claim 44, wherein:(a) the nucleoside reverse transcriptase inhibitor comprises abacavir, emtricitabine, lamivudine, tenofovir disoproxil fumarate, tenofovir alafenamide fumarate, zidovudine, or any combination thereof;(b) the non-nucleoside reverse transcriptase inhibitor comprises doravirine, efavirenz, etravirine. nevirapine, rilpivirine, or any combination thereof;(c) the protease inhibitor comprises atazanavir, darunavir, fosamprenavir, ritonavir, tipranavir, or any combination thereof;(d) the fusion inhibitor comprises enfuvirtide;(e) the CCR5 antagonist comprises maraviroc;(f) the integrase strand transfer inhibitor comprises cabotegravir, dolutegravir, raltegravir, bictegravir. or any combination thereof;(g) the attachment inhibitor comprises fostemsavir;(h) the post-attachment inhibitor comprises ibalizumab-uiyk;(i) the capsid inhibitor comprises lenacapavir;(j) the pharmacokinetic enhancer comprises cobicistat;(k) the anti-HIV antibody comprises N6-LS antibody, 3BNC117-LS antibody, 10-1074-LS antibody, or VRC07-523-LS antibody; or(l) the combination antiretroviral therapy comprises Epzicom (abacavir and lamivudine); Triumeq (abacavir, dolutegravir, and lamivudine); Trizivir (abacavir, lamivudine, and zidovudine); Evotaz (atazanavir and cobicistat); Biktarvy (bictegravir, emtricitabine. and tenofovir alafenamide); Cabenuva (cabotegravir and rilpivirine); Prezcobix (darunavir and cobicistat); Symtuza (darunavir, cobicistat, emtricitabine, and tenofovir alafenamide); Dovato (dolutegravir and lamivudine); Juluca (dolutegravir and rilpivirine); Destrigo (doravirine. lamivudine, and tenofovir disoproxil fumarate); Syrnfi (efavirenz, lamivudine, and tenofovir disoproxil fumarate); Genvoya (elvitegravir, cobicistat, emtricitabine, and tenofovir alafenamide); Stribild (elvitegravir, cobicistat. emtricitabine, and tenofovir disoproxil106178476135.1fumarate); Odefsey (emtricitabine, rilpivirine,and tenofovir alafenamide); Complera (emtricitabine, rilpivirine, and tenofovir disoproxil fumarate); Descovy (emtricitabine and tenofovir alafenamide); Truvada (emtricitabine and tenofovir disoproxil fumarate); Cimduo (lamivudine and tenofovir disoproxil fumarate); or Kaletra (lopinavir and ritonavir).

48. The method of any one of claims 36-47, wherein the subject has a blood or plasma level of <50 copies / mL of HIV-RNA at 6 months following administration of a single dose of the antibody or antigen-binding fragment.

49. The method of any one of claims 36-48, wherein the subject has a blood or plasma level of <50 copies / mL of HIV-RNA at 12 months following administration of a single dose of the antibody or antigen-binding fragment.

50. The method of any one of claims 36-49, wherein the antibody or antigenbinding fragment thereof is administered intravenously to the subject at a dose from about 1 mg / kg (i.e., about 70 mg for a 70 kg subject) to about 120 mg / kg (i.e., about 8,400 mg for a 70 kg subject); about 2 mg / kg (i.e., about 140 mg for a 70 kg mammal) to about 115 mg / kg (i.e., about 8,050 mg for a 70 kg subject); about 2 mg / kg (i.e., about 140 mg for a 70 kg subject) to about 110 mg / kg (i.e., about 7,700 mg for a 70 kg subject); about 2 mg / kg (i.e., about 140 mg for a 70 kg subject) to about 50 mg / kg (i.e.. about 3,500 mg for a 70 kg subject); about 2 mg / kg (i.e.. about 140 mg for a 70 kg subject) to about 45 mg / kg (i.e., about 3,150 mg for a 70 kg subject); about 5 mg / kg (i.e., about 350 mg for a 70 subject) to about 115 mg / kg (i.e., about 8,050 mg for a 70 kg subject); or about 5 mg / kg (i.e., about 350 mg for a 70 kg subject) to about 110 mg / kg (i.e., about 7.700 mg for a 70 kg subject).

51. The method of any one of claims 36-49, wherein the antibody or antigenbinding fragment thereof is administered intravenously to the subject at a dose of about 100 mg, 200 mg, 300 mg, 400 mg, 500 mg, 600 mg, 700 mg, 800 mg, 900 mg, 1000 mg, 1100 mg, 1200 mg, 1300 mg, 1400 mg, 1500 mg, 1600 mg, 1700 mg, 1800 mg, 1900 mg, 2000 mg, 2250 mg, 2500 mg, 2750 mg, 3000 mg. 3250 mg, 3500 mg , 3750 mg, 4000 mg, 4250 mg, 4500 mg, 4750 mg, 5000 mg, 5250 mg, 5500 mg, 5750 mg, 6000 mg, 6250 mg, 6500 mg, 6750 mg, 7000 mg, 7250 mg, 7500 mg, 7750 mg, 8000 mg, 8250 mg, 8500 mg, 8750107178476135.1mg, 9000 mg, 9250 mg, 9500 mg, 9750 mg, 10000 mg, 11000 mg, 12000 mg, 13000 mg, 14000 mg, 15000 mg, 16000 mg, 17000 mg, 18000 mg, 19000 mg. 20000 mg, 22500 mg, or 25000 mg.

52. The antibody or antigen-binding fragment of any one of claims 1-22, the polynucleotide of any one of claims 23-28, the recombinant vector of claim 29, the host cell of claim 30, the human B cell of claim 31, and / or the composition of claim 32, for use in a method of treating or preventing HIV-1 infection in a subject.

53. The antibody or antigen-binding fragment of any one of claims 1-22, the polynucleotide of any one of claims 23-28, the recombinant vector of claim 29, the host cell of claim 30, the human B cell of claim 31. and / or the composition of claim 32, for use in the preparation of a medicament for treating or preventing HIV-1 infection in a subject.108178476135.1

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