AU2018399587A1

AU2018399587A1 - Bispecific HIV-1-neutralizing antibodies

Info

Publication number: AU2018399587A1
Application number: AU2018399587A
Authority: AU
Inventors: David D. Ho; Yaoxing Huang; Jian Yu
Original assignee: Columbia University of New York
Current assignee: Columbia University of New York
Priority date: 2017-12-21
Filing date: 2018-12-20
Publication date: 2020-07-09
Also published as: EP3728311A1; TWI745643B; CN111819196A; JP2021506945A; CN111819196B; EP3728311A4; WO2019135921A1; TW201938583A; CA3085351A1; JP7345861B2

Abstract

In various embodiments, the present invention relates generally to using bispecific antibodies in the prevention and treatment of HIV.

Description

BISPECIFIC HIV - 1 -NEUTRALIZIN G ANTIBODIES

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of ET.S. Patent Application No. 15/414,822, filed January 25, 2017, which is a divisional of ET.S. Patent Application No. 14/558,341, filed

December 2, 2014, which is patented as ET.S. Patent No. 9,587,012, which claims priority to and the benefit of U.S. Provisional Patent Application No. 61/910,685, filed December 2, 2013, each of which is hereby incorporated by reference in its entirety.

FIELD OF THE INVENTION

SEQUENCE LISTING

The instant application contains a Sequence Listing which has been submitted in ASCII format via EFS-Web and is hereby incorporated by reference in its entirety. Said ASCII copy, created December 21, 2017, is named ADR-00lCP_ST25.txt and is 145,851 bytes in size. BACKGROUND

Passive immunization with antibodies (Abs) is a recognized method of prophylaxis and treatment of infectious diseases. This approach may involve preparing human immunoglobulins from donors who recovered from an infectious disease and utilizing such preparations, containing Abs specific for the infectious organism, to protect a recipient against the same disease. Alternatively, therapeutic antibodies can be made by immunizing mice with an antigen, and then engineering/humanizing the mouse Ab into a human version. Monoclonal antibodies (mAbs) are homogeneous in terms of physical characteristics and immunochemical reactivity, and so offer the possibility of absolute specific activity. That specificity can ultimately be a limitation for some targets, so practitioners have developed “bi specific” mAbs composed of fragments of two different mAbs and which bind to two different types of antigen. This facilitates binding to antigens expressed only weakly, for example. Some bispecific mAbs can stimulate strong immune responses, limiting their clinical application. One recent approach to ameliorating this effect is“CrossMab” methodology, a bispecific antibody format that adopts a more native antibody-like structure.

The prospects for generating a highly potent bispecific or bivalent antibody against a pathogen, such as HIV, for clinical use involves many uncertainties. The low spike density and spike structure on HIV may impede bivalent binding of antibodies to HIV, for example, and the geometry and spatial relationship of cell surface anchoring are not well-characterized. Nor is it known whether sufficient epitope accessibility on the HIV envelope exists. CrossMab bispecific antibodies that are anchored to a host cell membrane offer the possibility of improved local antibody concentration, targeting of sequential and/or interdependent entry steps, and

compensating for monovalent binding. Further still, large-scale, commercial production of antibodies remains challenging. For example, the production of therapeutic antibodies often requires the use of very large cell cultures followed by extensive purification steps, under Good Manufacturing Practice conditions, thereby resulting in extremely high production costs. Other limitations such as poor insolubility, protein aggregation, and protein instability can also make manufacturing of antibodies less than optimal.

Accordingly, there remains a need for therapeutically effective HIV antibodies that can be easily produced at a commercial scale.

SUMMARY

In one aspect, the present invention pertains to a bispecific antibody for neutralizing HIV. The bispecific antibody includes portions of a first and a second antibody, in which the first antibody binds to a HIV envelope protein. In certain embodiments, the first antibody is selected from PGT145, PG9, PGT128, PGT121, 10-1074, 3BNC117, VRC01, PGT151, 4E10, 10E8 and a variant thereof. In certain embodiments, the bispecific antibody includes portions of a second antibody, in which the second antibody binds to a cell membrane protein. For example, the second antibody binds to a cell receptor protein or a cell membrane co-receptor protein. In an embodiment, the second antibody is selected from a CD4 antibody, a CCR5 antibody and a CXCR4 antibody, such as Pro 140, ibalizumab, 515H7, or a variant thereof. In various embodiments, the bispecific antibody has a CrossMab format.

In another aspect, the present invention provides a bispecific antibody including portions of a first antibody and a second antibody, wherein the first antibody binds to a HIV envelope protein and the second antibody binds to a cell membrane protein. In various embodiments, the bispecific antibody has a CrossMab format.

In various embodiments, pharmaceutical compositions including the bispecific antibodies disclosed herein are also provided. The pharmaceutical composition may be formulated for oral, intranasal, pulmonary, intradermal, transdermal, subcutaneous, intramuscular, intraperitoneal, or intravenous delivery.

In a further aspect, methods for neutralizing HIV are provided. The methods include the steps of contacting an antigen binding site with a bispecific antibody that binds a HIV envelope protein and contacting another antigen binding site with a bispecific antibody that binds a cell membrane protein. In another aspect, methods for treating a patient infected with HIV are also provided. The methods include administering to the patient any of the bispecific antibodies or pharmaceutical compositions as disclosed herein. In an embodiment, the patient is human.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, like reference characters generally refer to the same parts throughout the different views. Also, the drawings are not necessarily to scale, with an emphasis instead generally being placed upon illustrating the principles of the invention. In the following description, various embodiments of the present invention are described with reference to the following drawings, in which:

Figure l is a diagram illustrating a CrossMab antibody derived from two IgG monoclonal antibodies.

Figure 2A is a diagram illustrating an iMab antibody (shorthand for the monoclonal antibody ibalizumab) that targets CD4 and a Pro 140 antibody that targets CCR5.

Figure 2B is a diagram illustrating mAbs that target the HIV envelope gpl20.

Figure 3 is a graph comparing the maximum percentage inhibition (MPI) against cell-to-cell HIV transmission using a combination of iMab and 10E8 antibodies with CrossMab bispecific l0E8/iMab antibodies. Except otherwise stated, all iMab-based bispecific antibodies were constructed using the MV 1 variant.

Figures 4A-J are a series of graphs comparing the inhibition of various strains of X4 and dual- tropic HIV using varying concentrations of 10E8, Pro 140 or 10E8/P140 antibodies. P140 is shorthand for Pro 140.

Figures 5A-G are a series of graphs comparing the inhibition of various strains of HIV using varying concentrations of 10E8, Pro 140, 10E8/P140 or a combination of the individual 10E8 and Pro 140 monoclonal antibodies.

Figures 6A-D are a series of graphs comparing the inhibition of various strains of HIV using varying concentrations of 10E8, X19, 10E8/X19 or 10E8/P140 antibodies.

Figures 7A-H are a series of graphs comparing the inhibition of various strains of HIV using varying concentrations of 10E8, Pro 140, 10E8/P140 and lOE8/aHer2 antibodies.

Figure 8 A is a graph comparing the binding of CrossMab bispecific antibodies l0E8/iMab and D 10E8/iMab to the HIV-l glycoprotein MPER. Figures 8B-E are a series of graphs comparing the inhibition percentages of 10E8 (light gray lines) and D10E8 (dark gray lines) against iMab resistant R5 viruses (Figure 8B) and X4 viruses (Figure 8C), as well as the inhibition percentages of l0E8/iMab (light gray lines) and

D 10E8/iMab (dark gray lines) against iMab resistant R5 viruses (Figure 8D) and X4 viruses (Figure 8E).

Figures 9A-G are a series of graphs comparing the inhibition of various strains of HIV using varying concentrations of 10E8, D10E8, 4E10, 10E8/P140, D10E8/R140 and 4E10/P140 antibodies.

Figure 10 is a graph comparing the antiviral coverage of the CrossMab antibodies l0E8/Prol40 and l0E8/iMab, their parental monoclonal antibodies 10E8, Pro 140 and iMab, and various other HIV envelope-targeting monoclonal antibodies against a large panel of HIV envelope pseudotyped viruses.

Figures 11 A-E are a series of graphs comparing the maximum percentage inhibition (MPI) of a large panel of HIV envelope pseudotyped viruses with the monoclonal antibody iMab (grey bars in all panels) and the CrossMab antibodies PGTl45/ibalizumab (l45/iMab; Figure 11 A), PGTl28/ibalizumab (l28/iMab; Figure 11B), PGTl5l/ibalizumab (l5l/iMab; Figure 11C), 3BNC1 l7/ibalizumab (H7/iMab; Figure 11D) and l0E8/ibalizumab (l0E8/iMab; Figure 11E).

Figures 12A-E are a series of graphs comparing the maximum percentage inhibition (MPI) and IC80 antibody concentrations of the CrossMab antibodies PGTl45/ibalizumab (l45/iMab; Figure 12 A), PGTl28/ibalizumab (l28/iMab; Figure 12B), PGTl5l/ibalizumab (l5l/iMab;

Figure 12C), 3BNC1 l7/ibalizumab (H7/iMab; Figure 12D) and l0E8/ibalizumab (l0E8/iMab; Figure 12E) against a large panel of HIV envelope pseudotyped viruses.

Figures 13 A-E are a series of graphs comparing the IC80 antibody concentrations for iMab- and Prol40-based CrossMab bispecific antibodies and their parent antibodies for PGTl45/iMab and PGT145/Pro 140 (Figure 13A), 3BNCl l7/iMab and 3BNC117/Pro 140 (Figure 13B), PGTl28/iMab and PGTl28/Prol40 (Figure 13C), PGTl5l/iMab and PGTl5l/Prol40 (Figure 13D) and lOE8/iMab and l0E8/Prol40 (Figure 13E).

Figures 14A-E are a series of graphs comparing the IC50 antibody concentrations for iMab- and Prol40-based CrossMab bispecific antibodies and their parent antibodies for PGTl45/iMab and PGT145/Pro 140 (Figure 14 A), 3BNCl l7/iMab and 3BNC117/Pro 140 (Figure 14B),

PGTl28/iMab and PGTl28/Prol40 (Figure 14C), PGTl5l/iMab and PGTl5l/Prol40 (Figure 14D) and l0E8/iMab and l0E8/Prol40 (Figure 14E).

Figures 15A-E are graphs displaying the IC80 antibody concentrations for iMab-based

CrossMab bispecific antibodies and their parent antibodies against cell-to-cell transmission of HIV for l0E8/iMab (Figure 15A), 3BNC1 l7/iMab (Figure 15B), PGTl45/iMab (Figure 15C), PGTl28/iMab (Figure 15D) and PGTl5l/iMab (Figure 15E).

Figure 16 is a graph displaying the maximum percent inhibition (MPI) of CrossMab bispecific antibodies and parental antibodies against cell-to-cell transmission of HIV.

Figure 17A is a graph comparing the inhibition of an HIV strain against varying concentrations of 10E8, Pro 140, 10E8/P140 CrossMab bispecific antibody, and a combination of individual 10E8 and Pro 140 monoclonal antibodies.

Figure 17B is a graph comparing the inhibition of an HIV strain against varying concentrations of iMab, 10E8, l0E8/iMab CrossMab bispecific antibody, and a combination of individual 10E8 and iMab monoclonal antibodies. Figures 18A-D are a series of graphs comparing the inhibition of various HIV R5 strains against varying concentrations of 10E8, Prol40, 10E8/P140 and 10E8/515H7 antibodies.

Figures 18E-H are a series of graphs comparing the inhibition of various HIV X4 strains against various concentrations of 10E8, 515H7 and 10E8/515H7 antibodies. Figures 19A-B are a series of graphs comparing inhibition of various HIV strains against varying concentrations of l0E8/Prol40, l0E8/iMab, 10E8/515H7 and 10E8/X19 antibodies.

Figure 19C indicates the density of CD4, CCR5 and CXCR4 receptors present on TZM-bl cells.

Figure 20 compares the binding of CrossMab bispecific antibodies l0E8/Prol40, D10E8/RGO140 and 4E10/Pro 140 to the HIV-l glycoprotein MPER.

Figures 21A-G are a series of graphs comparing the inhibition of various strains of HIV against varying concentrations of 4E10, Prol40 and 4E10/P140 and 10E8/P140 antibodies.

Figure 22A is size exclusion chromatography analysis of the CrossMab antibodies l0E8/iMab, 10E8/P140 and 3BNC1 l7/iMab. Figure 22B is size exclusion chromatography analysis of the monoclonal antibodies iMab, 10E8 and Pro 140.

Figure 23 is size exclusion chromatography analysis of monoclonal antibody 10E8 and a chimeric antibody comprised of the 10E8 heavy chain paired with the 4E10 light chain.

Figures 24A-C are a series of size exclusion chromatography graphs of: the monoclonal antibodies 10E8 and 4E10 and a chimeric antibody comprised of the 10E8 heavy chain paired with the 4E10 light chain (Figure 24A), the monoclonal antibody 10E8 and 10E8 mutants with potentially stabilizing mutations genetically engineered in the 10E8 light chain (Figure 24B), and the monoclonal antibody 10E8 and 10E8 mutants genetically grafted with the kappa light chain of non-l0E8 antibodies (Figure 24C). Figure 25 is a size exclusion chromatography graph of the monoclonal antibody 4E10 and 4E10 mutants genetically grafted with the light regions of 10E8 that included the CDR1 region, CDR2 region, CDR3 region, or combined CDR1, CDR2 and CDR3 regions.

Figure 26A is a size exclusion chromatography graph of 10E8 chimeric antibodies. CDR123 is a chimeric antibody of the 10E8 heavy chain paired with a 10E8 light chain genetically grafted with the 10E8 antibody germline CDR region sequences. FW123 is a chimeric antibody of the 10E8 heavy chain paired with a 10E8 light chain genetically grafted with the 10E8 antibody germline framework region sequences.

Figure 26B is a table indicating the expression, HIV MPER binding ability, size exclusion chromatography profile, and HIV neutralization profile of the CDR123 and FW123 antibodies.

Figure 27 is a size exclusion chromatography graph of monoclonal antibody 10E8, its somatic variant H6L10, and a CrossMab bispecific antibody consisting of H6L10 paired with Prol40.

Figure 28 is a graph depicting the pharmacokinetics profiles of 10E8, H6LlO/Pro 140 and its parental antibodies in a mouse model. Figure 29 is a graph comparing the potency of l0E8_v i.o/iMab or P140 CrossMab antibodies with l0E8/iMab or P 140 antibodies.

Figure 30 is a graph depicting the pharmacokinetics of 10E8 and CrossMab antibodies derived from several 10E8 variants and iMab or P 140 in a mouse model.

Figures 31A-B are a series of graphs depicting the HIV viral coverage of 10E8_ni.i/R140 and lOE8v2.o/iMab antibodies.

Figures 31C-D are a series of graphs depicting size exclusion chromatography stability graphs of 10E8n_ΐ.i/R140 and lOE8_V2.o/iMab antibodies.

Figures 32A-B are a series of graphs depicting the size exclusion stability graphs of

10E8n_ΐ.i/R140 and lOE8_V2.o/iMab antibodies stored in PBS at 4°C. Figure 33 depicts a native mass spectroscopy analysis of the lOE8_V2.o/iMab (N297A) antibody.

Figures 34A-C are a series of graphs comparing the activity of 10E8_ni.i/R140 and lOE8_V2.o/iMab on a HIV Clade C panel, and the IC50 and IC80 activities of the antibodies. Figures 35 and 36 are graphs comparing the potency of 10E8_ni.i/R140, lOE8_V2.o/iMab, and various monoclonal antibodies against HIV.

Figures 37A-C demonstrate that a select number of l0E8V2.0/iMab (also referred to as lOE8.2/iMab) variants retained functional antiviral activity and increased solubility. Figure 37A demonstrates that some of the lOE8.2/iMab variants retained functional activity in an in vitro HIV-l neutralization assay. Figure 37B shows that lOE8.2/iMab and some of the lOE8.2/iMab variants have similar in vivo pharmacokinetic profiles. Figure 37C shows the precipitation profiles of lOE8.2/iMab and some of the lOE8.2/iMab variants under thermal stress-inducing conditions. Figures 38A-B show the results of size exclusion chromatography, which was used to identify lOE8.2/iMab variants with the least aggregation after thermal stress-inducing conditions.

Figures 39A-B illustrate the solubility of lOE8.2/iMab and the lOE8.4/iMab variant at 4°C after ultracentrifugati on .

Figure 40 demonstrates the turbidity of lOE8.2/iMab and the lOE8.4/iMab variant at different concentrations over time.

Figure 41 shows the thermostability of lOE8.2/iMab and the lOE8.4/iMab variant as assessed by differential scanning calorimetry.

Figure 42 demonstrates the turbidity of lOE8.2/iMab and the lOE8.4/iMab variant after forced degradation at 50°C for six days. For each set of histograms, the bars from left to right represent lOE8.2/iMab (pre-centrifugation), lOE8.4/iMab (pre-centrifugation), lOE8.2/iMab (post- centrifugation), and lOE8.4/iMab (post-centrifugation).

Figure 43 shows the anti-HIV coverage of lOE8.2/iMab and the lOE8.4/iMab variant.

Figure 44 is a graph showing the in vivo antiviral activity of lOE8.2/iMab and the lOE8.4/iMab variant in a humanized mouse model of HIV-l infection. Figure 45A, shows a sequence alignment of the light chains of lOE8.2/iMab (SEQ ID NO:33) and the lOE8.4/iMab variant (SEQ ID NO:44).

Figure 45B shows a sequence alignment of the heavy chains of lOE8.2/iMab (SEQ ID NO:34) and the lOE8.4/iMab variant (SEQ ID NO:42). ETnderlined sequences denote CDR1, CDR2, and CDR3. Italicized sequences denote constant light chain or constant heavy chain sequences.

Figure 46 is a graph showing exemplary variants of 10E8 antibodies that are stable while retaining anti-HIV activity.

DETAILED DESCRIPTION

Embodiments of the present invention provide for inhibition of HIV. In various

implementations, bispecific antibodies are formed, each including heavy chain and light chain components from two different parent antibodies. In various embodiments, one parent antibody specifically binds HIV, for example, the HIV envelope protein Env. In various embodiments, the other parent antibody specifically binds a cell membrane protein, for example CD4 and CCR5. In various embodiments, the bispecific antibody ( e.g ., a HIV CrossMab antibody) of the present invention has the natural architecture of an IgG molecule, but with bispecificity. In a bispecific antibody, a heavy chain and light chain from each of two parental antibodies are combined, providing an antibody in which the antigen binding sites of fragment antigen-binding 1 (Fabl) and Fab2 have different binding specificities. In certain embodiments, the bispecific antibody is a CrossMab format antibody, as shown in Figure 1. In a CrossMab format, one heavy chain includes a“knob” structure and the other heavy chain includes a corresponding“hole” structure, and the positions of the constant domains (i.e., CL and CH1) from one parental antibody are switched, which together ensure correct pairing of heavy chains and light chains during assembly. Various mAbs have been shown to block HIV infection by targeting and binding to the HIV envelope protein Env (Figures 2B and 10). These mAbs include, for example, PGT145, PG9, PGT128, PGT121, 10-1074, 3BNC117, VRC01, PGT151, 4E10, and 10E8. Figure 2B (adapted from www.scripps.edu/news/press/20l4/20l40424hiv.html) illustrates how the mAb PGT145 targets the V 1/V2 epitope on the HIV viral envelope gpl20; how mAb PGT128 targets the glycan on the V3 stem region of HIV gpl20; how mAb 3BNC117 targets the CD4 binding site of HIV gpl20; how mAb 10E8 targets the membrane proximal external region (MPER) of HIV gp4l; and how mAb PGT151 targets an epitope on both HIV gpl20 and HIV gp4l.

In addition, monoclonal antibodies Pro 140 (“P140”), Ibalizumab (“iMab”) and 515H7 have been shown to block HIV infection by targeting and binding to CCR5, CD4 and CXCR4 human cell membrane proteins, respectively (Figure 2A). Specifically, Figure 2A shows how iMab targets CD4, the primary receptor for HIV-l entry that is expressed on human T-cells; and how Pro 140 targets CCR5, a co-receptor for HIV-l entry by CCR5 tropic HIV-l.

Although the ensuing discussion focuses on the use of bispecific antibodies directed to Env and the cell membrane proteins CD4 and CCR5, it is to be understood that this is solely for ease of presentation, and that any suitable antibody directed to any HIV epitope and any suitable antibody directed to any suitable cell membrane protein may be used and are within the scope of the invention.

Accordingly, in various embodiments, the present invention provides bispecific antibodies that target and bind to the HIV Env protein as well as the cell membrane proteins CCR5, CD4 and/or CXCR4. In certain embodiments, the bispecific antibodies include sequences (for example, heavy and light chain sequences) derived from, but not limited to, the PGT145, PG9, PGT128, PGT121, 10-1074, 3BNC117, VRC01, PGT151, 4E10, and/or 10E8 antibodies and variants thereof. The amino acid sequences defining the heavy and light chains of the PGT145 antibody can be found, for example, at www.ncbi.nlm.nih.gov/protein/3UlS_H and http://www.ncbi.nlm.nih.gov/protein/3UlS_L, respectively, the entire contents of which are incorporated herein by reference.

The amino acid sequences defining the heavy and light chains of the PG9 antibody can be found, for example, at www dot ncbi dot nlm dot nih dot gov/protein/3U4E_H and www dot ncbi dot nlm dot nih dot gov/protein/3MUH_L, respectively, the entire contents of which are incorporated herein by reference.

The amino acid sequences defining the heavy and light chains of the PGT128 antibody can be found, for example, at www dot ncbi dot nlm dot nih dot gov /protein/3 TYG H and www dot ncbi dot nlm dot nih dot gov protein/3 TYG L, respectively, the entire contents of which are incorporated herein by reference.

The amino acid sequences defining the heavy and light chains of the PGT121 antibody can be found, for example, at www dot ncbi dot nlm dot nih dot gov /protein/4FQC_H and www dot ncbi dot nlm dot nih dot gov/protein/4FQC_L, respectively, the entire contents of which are incorporated herein by reference. The amino acid sequences defining the heavy and light chains of the 10-1074 antibody can be found, for example, in Mouquet FL, et al. , (2012) PNAS, 109(47): E3268-77 (including supplementary information), the entire contents of which are incorporated herein by reference.

The amino acid sequences defining the heavy and light chains of the 3BNC117 antibody can be found, for example, at www dot ncbi dot nlm dot nih dot gov/protein/4LSV_H and www dot ncbi dot nlm dot nih dot gov/protein/4LSV_L, respectively, the entire contents of which are incorporated herein by reference.

The amino acid sequences defining the heavy and light chains of the VRC01 antibody can be found, for example, at www dot ncbi dot nlm dot nih dot gov/protein/4LST_H and www dot ncbi dot nlm dot nih dot gov/protein/4LST_L, respectively, the entire contents of which are incorporated herein by reference. The amino acid sequences defining the heavy and light chains of the PGT151 antibody can be found, for example, at www dot ncbi dot nlm dot nih dot gov/protein/4NUG_H and www dot ncbi dot nlm dot nih dot gov/protein/4NUG_L, respectively, the entire contents of which are incorporated herein by reference. The amino acid sequences defining the heavy and light chains of the 4E10 antibody can be found, for example, at www dot ncbi dot nlm dot nih dot gov/protein/4LLV_H and www dot ncbi dot nlm dot nih dot gov/protein/4LLV_L, respectively, the entire contents of which are incorporated herein by reference.

The amino acid sequences defining the heavy and light chains of the 10E8 antibody can be found, for example, at www dot ncbi dot nlm dot nih dot gov/protein/4G6F_B and www dot ncbi dot nlm dot nih dot gov/protein/4G6F_D, respectively, the entire contents of which are incorporated herein by reference.

In certain embodiments, the bispecific antibodies include sequences (for example, heavy and light chain sequences) derived from, but not limited to, the P140, iMab (or the MV1 variant) and/or 515H7 antibodies and variants thereof. The heavy and light chain sequences of the Pro 140, iMab (or its MV1 variant), and 515H7 antibodies are further described, for example, in Olson, W. C. et al. , (1999) J Virol., 73(5):4l45-55, Trkola, A. et al. , (2001) J Virol., 75(2):579- 88, U.S. Patent No. 7,122,185, Burkly L. C. et al. , (1992) J Immunol., 149(5): 1779-87, Moore J. P. et al. , (1992) J Virol., 66(8):4784-93, Reimann K. A., et al, (1997) AIDS Res Hum

Retroviruses, 13(11):933-43, International Patent Publication No. W02014100139, and

European Patent Publication No. EP2246364, the entire contents of all of which are incorporated herein by reference.

As used herein, an antibody“variant” refers to an antibody which has an amino acid sequence which differs from the amino acid sequence of a parent antibody from which it is derived. In various embodiments, the variant has one or more amino acid alterations with respect to the parent antibody. In various embodiments, the bispecific antibody of the present invention includes a heavy and light chain sequence from the PGT145, PG9, PGT128, PGT121, 10-1074, 3BNC117, VRC01, PGT151, 4E10, or 10E8 antibody or a variant thereof and a heavy and light chain sequence from the P140, iMab (or the MV1 variant), or 515H7 antibody or a variant thereof. In exemplary embodiments, a series of HIV CrossMab antibodies have been constructed including but not limited to, for example, 145/MV1, 117/MV1, 128/MV1, 10E8/MV1, 145/P140, 128/P140, 117/P140, 10E8/P140, lOE8/alpha-Her2, 10E8/X19, and 4E10/P140. PGT145 (“145”), 3BNC117 (“117”), PGT128 (“128”), and 10E8 are four different HIV envelope antibodies. Pro 140 (“P140”) is a mAb that binds to the cell surface receptor CCR5. MV1 is a CD4 antibody that is a modified variant of the mAb Ibalizumab (“iMab”; see, for example, International Patent Publication No. W02014100139, incorporated herein by reference in its entirety). XI 9 is one of the antibody variants of the anti-cell surface receptor CXCR4 (see, for example, U.S. Patent No. 8,329,178, incorporated herein by reference in its entirety) that does not bind to cells expressing CXCR4 (and is therefore used as a non-surface binding control). Alpha-Her2 is a mAb that binds to the Her2 receptor expressed on cells. Many of these

CrossMab antibodies increase the breadth of HIV neutralization as compared to their parental antibodies (i.e., monoclonal antibodies MV1, 145, 117 or 10E8). In various embodiments, the bispecific antibodies of the invention significantly increase the potency of neutralization against HIV as compared to their parental antibodies. The amino acid sequences defining the heavy and light chains of various exemplary HIV

CrossMab antibodies are shown below.

145/MV 1 antibody:

Amino acid sequence defining the MV1 derived light chain of the 145/MV 1 antibody - MV1- VLCH1 (SEQ ID NO:l): DIVMTQSPDSLAVSLGERVTMNCKSSQSLLYSTNQKNYLAWYQQKPGQSPKLLIYWASTRESGVPDRFSG SGSGTDFTLT I S SVQAEDVAVYYCQQYY SYRT FGGGTKLE IKSSASTKGPSVFPLAPS SKST SGGTAALG CLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDK

KVEPKSC

Amino acid sequence defining the MV1 derived heavy chain of the 145/MV 1 antibody - MV1- HC-Hole-Cross (SEQ ID NO:2): QVQLQQSGPEVVKPGASVKMSCKASGYTFTSYVIHWVRQKPGQGLDWIGYINPYNDGTDYDEKFKGKATL TSDTSTSTAYMELSSLRSEDTAVYYCAREKDNYATGAWFAYWGQGTLVTVSSASTAAPSVFI FPPSDEQL KSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYACE VTHQGLSSPVTKSFNRGECDKTHTCPPCPAPEFEGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDP EVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPASIEKTISKAKG QPREPQVCTLPPSRDELTKNQVSLSCAVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLVSKLT VDKSRWQQGNVFSCSVLHEALHSHYTQKSLSLSPGK

Amino acid sequence defining the PGT145 derived light chain of the 145/MV1 antibody - PGT145-LC (SEQ ID NO:3):

EVVITQSPLFLPVTPGEAASLSCKCSHSLQHSTGANYLAWYLQRPGQTPRLLIHLATHRASGVPDRFSGS GSGTDFTLKISRVESDDVGTYYCMQGLHSPWTFGQGTKVEIKRTVAAPSVFI FPPSDEQLKSGTASVVCL

LNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYACEVTHQGLSSPV TKSFNRGEC

Amino acid sequence defining the PGT145 derived heavy chain of the 145/MV1 antibody - PGTl45-HC-Knob (SEQ ID NO:4): QVQLVQSGAEVKKPGSSVKVSCKASGNSFSNHDVHWVRQATGQGLEWMGWMSHEGDKTGLAQKFQGRVTI TRDSGASTVYMELRGLTADDTAIYYCLTGSKHRLRDYFLYNEYGPNYEEWGDYLATLDVWGHGTAVTVSS ASTKGPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVT VPSSSLGTQTYICNVNHKPSNTKVDKKVEPKSCDKTHTCPPCPAPEFEGGPSVFLFPPKPKDTLMISRTP EVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKA LPASIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPV LDSDGSFFLYSKLTVDKSRWQQGNVFSCSVLHEALHSHYTQKSLSLSPGK

117/MV 1 antibody: Amino acid sequence defining the MV1 derived light chain of the 117/MV 1 antibody - MV1- VLCH1 (SEQ ID NO:!):

DIVMTQSPDSLAVSLGERVTMNCKSSQSLLYSTNQKNYLAWYQQKPGQSPKLLIYWASTRESGVPDRFSG SGSGTDFTLTISSVQAEDVAVYYCQQYYSYRTFGGGTKLEIKSSASTKGPSVFPLAPSSKSTSGGTAALG CLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDK KVEPKSC

Amino acid sequence defining the MV1 derived heavy chain of the 117/MV 1 antibody - MV1- HC-Hole-Cross (SEQ ID NO:2):

QVQLQQSGPEVVKPGASVKMSCKASGYTFTSYVIHWVRQKPGQGLDWIGYINPYNDGTDYDEKFKGKATL TSDTSTSTAYMELSSLRSEDTAVYYCAREKDNYATGAWFAYWGQGTLVTVSSASTAAPSVFI FPPSDEQL KSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYACE VTHQGLSSPVTKSFNRGECDKTHTCPPCPAPEFEGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDP EVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPASIEKTISKAKG QPREPQVCTLPPSRDELTKNQVSLSCAVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLVSKLT VDKSRWQQGNVFSCSVLHEALHSHYTQKSLSLSPGK

Amino acid sequence defining the 3BNC117 derived light chain of the 117/MV 1 antibody - 3BNC117-LC (SEQ ID NO: 5):

DIQMTQSPSSLSASVGDTVTITCQANGYLNWYQQRRGKAPKLLIYDGSKLERGVPSRFSGRRWGQEYNLT INNLQPEDIATYFCQVYEFVVFGQGTKVQVDIKRTVAAPSVFIFPPSDEQLKSGTASVVCLLNNFYPREA KVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYACEVTHQGLSSPVTKSFNRGEC

Amino acid sequence defining the 3BNC117 derived heavy chain of the 117/MV 1 antibody - 3BNC1 l7-HC-Knob (SEQ ID NO: 6):

QVQLLQSGAAVTKPGASVRVSCEASGYNIRDYFIHWWRQAPGQGLQWVGWINPKTGQPNNPRQFQGRVSL TRHASWDFDTFSFYMDLKALRSDDTAVYFCARQRSDYWDFDVWGQGTLVTVSSASTKGPSVFPLAPSSKS TSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNH KPSNTKVDKKVEPKSCDKTHTCPPCPAPEFEGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVK FNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPASIEKTISKAKGQPR EPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDK

SRWQQGNVFSCSVLHEALHSHYTQKSLSLSPGK

128/MV 1 antibody:

Amino acid sequence defining the MV1 derived light chain of the 128/MV 1 antibody - MV1- VLCH1 (SEQ ID NO:l):

DIVMTQSPDSLAVSLGERVTMNCKSSQSLLYSTNQKNYLAWYQQKPGQSPKLLIYWASTRESGVPDRFSG SGSGTDFTLTISSVQAEDVAVYYCQQYYSYRTFGGGTKLEIKSSASTKGPSVFPLAPSSKSTSGGTAALG CLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDK KVEPKSC Amino acid sequence defining the MV1 derived heavy chain of the 128/MV 1 antibody - MV1- HC-Hole-Cross (SEQ ID NO:2):

Amino acid sequence defining the PGT128 derived light chain of the 128/MV 1 antibody - PGT128-LC (SEQ ID NO: 7):

QSALTQPPSASGSPGQSITISCTGTSNNFVSWYQQHAGKAPKLVIYDVNKRPSGVPDRFSGSKSGNTASL TVSGLQTDDEAVYYCGSLVGNWDVIFGGGTKLTVLGQPKAAPSVTLFPPSSEELQANKATLVCLISDFYP GAVTVAWKADSSPVKAGVETTTPSKQSNNKYAASSYLSLTPEQWKSHRSYSCQVTHEGSTVEKTVAPTEC S Amino acid sequence defining the PGT128 derived heavy chain of the 128/MV 1 antibody - PGTl28-HC-Knob (SEQ ID NO:8): QPQLQESGPTLVEASETLSLTCAVSGDSTAACNSFWGWVRQPPGKGLEWVGSLSHCASYWNRGWTYHNPS LKSRLTLALDTPKNLVFLKLNSVTAADTATYYCARFGGEVLRYTDWPKPAWVDLWGRGTLVTVSSASTKG PSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSS LGTQTYICNVNHKPSNTKVDKKVEPKSCDKTHTCPPCPAPEFEGGPSVFLFPPKPKDTLMISRTPEVTCV VVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPASI EKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDG SFFLYSKLTVDKSRWQQGNVFSCSVLHEALHSHYTQKSLSLSPGK

10E8/MV1 antibody:

Amino acid sequence defining the MV1 derived light chain of the 10E8/MV1 antibody - MV1- VLCH1 (SEQ ID NO: l):

Amino acid sequence defining the MV1 derived heavy chain of the 10E8/MV1 antibody - MV1- HC-Hole-Cross (SEQ ID NO:2):

Amino acid sequence defining the 10E8 derived light chain of the 10E8/MV1 antibody - 10E8-LC (SEQ ID NO: 9):

YELTQETGVSVALGRTVTITCRGDSLRSHYASWYQKKPGQAPILLFYGKNNRPSGVPDRFSGSASGNRAS

LTISGAQAEDDAEYYCSSRDKSGSRLSVFGGGTKLTVLSQPKAAPSVTLFPPSSEELQANKATLVCLISD FYPGAVTVAWKADSSPVKAGVETTTPSKQSNNKYAASSYLSLTPEQWKSHRSYSCQVTHEGSTVEKTVAP

TECS

Amino acid sequence defining the 10E8 derived heavy chain of the 10E8/MV1 antibody - 10E8- HC-Knob (SEQ ID NO: 10):

EVQLVESGGGLVKPGGSLRLSCSASGFDFDNAWMTWVRQPPGKGLEWVGRITGPGEGWSVDYAAPVEGRF TISRLNSINFLYLEMNNLRMEDSGLYFCARTGKYYDFWSGYPPGEEYFQDWGRGTLVTVSSASTKGPSVF PLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQ TYICNVNHKPSNTKVDKKVEPKSCDKTHTCPPCPAPEFEGGPSVFLFPPKPKDTLMISRTPEVTCVVVDV SHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPASIEKTI SKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFL YSKLTVDKSRWQQGNVFSCSVLHEALHSHYTQKSLSLSPGK

Al0E8/MVl antibody

Amino acid sequence defining the MV1 derived light chain of the D 10E8/MV 1 antibody MV1- VLCH1 (SEQ ID NO: l):

Amino acid sequence defining the MV1 derived heavy chain of the D 10E8/MV 1 antibody MV1- HC-Hole-Cross (SEQ ID NO:2):

QVQLQQSGPEVVKPGASVKMSCKASGYTFTSYVIHWVRQKPGQGLDWIGYINPYNDGTDYDEKFKGKATL TSDTSTSTAYMELSSLRSEDTAVYYCAREKDNYATGAWFAYWGQGTLVTVSSASTAAPSVFI FPPSDEQL KSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYACE VTHQGLSSPVTKSFNRGECDKTHTCPPCPAPEFEGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDP EVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPASIEKTISKAKG QPREPQVCTLPPSRDELTKNQVSLSCAVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLVSKLT

VDKSRWQQGNVFSCSVLHEALHSHYTQKSLSLSPGK

Amino acid sequence defining the D 10E8 derived light chain of the AlOE8/MVl antibody D10E8- LC (SEQ ID NO:2l): YELTQETGVSVALGRTVTITCRGDSLRSHYASWYQKKPGQAPILLFYGKNNRPSGVPDRFSGASGNRASL TISGAQAEDDAEYYCSSRDKSGSRLSVFGGGTKLTVLSQPKAAPSVTLFPPSSEELQANKATLVCLISDF YPGAVTVAWKADSSPVKAGVETTTPSKQSNNKYAASSYLSLTPEQWKSHRSYSCQVTHEGSTVEKTVAPT ECS

Amino acid sequence defining the D 10E8 derived heavy chain of the D 10E8/MV 1 antibody 10E8- HC-Knob (SEQ ID NO:22):

151/MV1 antibody

Amino acid sequence defining the MV1 derived light chain of the 151/MV1 antibody - MV1- VLCH1 (SEQ ID NO: 1):

DIVMTQSPDSLAVSLGERVTMNCKSSQSLLYSTNQKNYLAWYQQKPGQSPKLLIYWASTRESGVPDRFSG SGSGTDFTLTISSVQAEDVAVYYCQQYYSYRTFGGGTKLEIKSSASTKGPSVFPLAPSSKSTSGGTAALG CLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDK KVEPKSC Amino acid sequence defining the MV 1 derived heavy chain of the 15 l/MV 1 antibody MV 1 -HC-

Hole-Cross (SEQ ID NO:2): QVQLQQSGPEVVKPGASVKMSCKASGYTFTSYVIHWVRQKPGQGLDWIGYINPYNDGTDYDEKFKGKATL TSDTSTSTAYMELSSLRSEDTAVYYCAREKDNYATGAWFAYWGQGTLVTVSSASTAAPSVFI FPPSDEQL KSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYACE VTHQGLSSPVTKSFNRGECDKTHTCPPCPAPEFEGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDP EVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPASIEKTISKAKG QPREPQVCTLPPSRDELTKNQVSLSCAVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLVSKLT VDKSRWQQGNVFSCSVLHEALHSHYTQKSLSLSPGK

Amino acid sequence defining the PGT151 derived light chain of the 151/MV1 antibody PGT151- LC (SEQ ID NO:23): DIVMTQTPLSLSVTPGQPASISCKSSESLRQSNGKTSLYWYRQKPGQSPQLLVFEVSNRFSGVSDRFVGS GSGTDFTLRISRVEAEDVGFYYCMQSKDFPLTFGGGTKVDLKRTVAAPSVFI FPPSDEQLKSGTASVVCL LNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYACEVTHQGLSSPV TKSFNRGEC

Amino acid sequence defining the PGT151 derived heavy chain of the 151/MV1 antibody PGT 151 -HC-Knob (SEQ ID NO:24):

RVQLVESGGGVVQPGKSVRLSCVVSDFPFSKYPMYWVRQAPGKGLEWVAAISGDAWHVVYSNSVQGRFLV SRDNVKNTLYLEMNSLKIEDTAVYRCARMFQESGPPRLDRWSGRNYYYYSGMDVWGQGTTVTVSSASTKG PSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSS LGTQTYICNVNHKPSNTKVDKKVEPKSCDKTHTCPPCPAPEFEGGPSVFLFPPKPKDTLMISRTPEVTCV VVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPASI EKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDG SFFLYSKLTVDKSRWQQGNVFSCSVLHEALHSHYTQKSLSLSPGK

145/P 140 antibody:

Amino acid sequence defining the Pro 140 derived light chain of the 145/P 140 antibody - PRO 140- VLCH1 (SEQ ID NO: 11):

DIVMTQSPLSLPVTPGEPASISCRSSQRLLSSYGHTYLHWYLQKPGQSPQLLIYEVSNRFSGVPDRFSGS GSGTDFTLKISRVEAEDVGVYYCSQSTHVPLTFGQGTKVEIKSSASTKGPSVFPLAPSSKSTSGGTAALG CLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDK

KVEPKSC

Amino acid sequence defining the Pro 140 derived heavy chain of the 145/P 140 antibody - PRO 140-HC -Hole-Cross (SEQ ID NO: 12): EVQLVESGGGLVKPGGSLRLSCAASGYTFSNYWIGWVRQAPGKGLEWIGDIYPGGNYIRNNEKFKDKTTL SADTSKNTAYLQMNSLKTEDTAVYYCGSSFGSNYVFAWFTYWGQGTLVTVSSASTAAPSVFI FPPSDEQL KSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYACE VTHQGLSSPVTKSFNRGECDKTHTCPPCPAPEFEGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDP EVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPASIEKTISKAKG QPREPQVCTLPPSRDELTKNQVSLSCAVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLVSKLT VDKSRWQQGNVFSCSVLHEALHSHYTQKSLSLSPGK

Amino acid sequence defining the PGT145 derived light chain of the 145/P 140 antibody - PGT145-LC (SEQ ID NO:3):

EVVITQSPLFLPVTPGEAASLSCKCSHSLQHSTGANYLAWYLQRPGQTPRLLIHLATHRASGVPDRFSGS GSGTDFTLKISRVESDDVGTYYCMQGLHSPWTFGQGTKVEIKRTVAAPSVFI FPPSDEQLKSGTASVVCL LNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYACEVTHQGLSSPV TKSFNRGEC

Amino acid sequence defining the PGT145 derived heavy chain of the 145/P 140 antibody - PGTl45-HC-Knob (SEQ ID NO:4): QVQLVQSGAEVKKPGSSVKVSCKASGNSFSNHDVHWVRQATGQGLEWMGWMSHEGDKTGLAQKFQGRVTI TRDSGASTVYMELRGLTADDTAIYYCLTGSKHRLRDYFLYNEYGPNYEEWGDYLATLDVWGHGTAVTVSS ASTKGPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVT VPSSSLGTQTYICNVNHKPSNTKVDKKVEPKSCDKTHTCPPCPAPEFEGGPSVFLFPPKPKDTLMISRTP EVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKA LPASIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPV LDSDGSFFLYSKLTVDKSRWQQGNVFSCSVLHEALHSHYTQKSLSLSPGK

117/P 140 antibody: Amino acid sequence defining the Pro 140 derived light chain of the 117/P 140 antibody - PRO 140- VLCH1 (SEQ ID NO: 11):

DIVMTQSPLSLPVTPGEPASISCRSSQRLLSSYGHTYLHWYLQKPGQSPQLLIYEVSNRFSGVPDRFSGS GSGTDFTLKISRVEAEDVGVYYCSQSTHVPLTFGQGTKVEIKSSASTKGPSVFPLAPSSKSTSGGTAALG CLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDK KVEPKSC

Amino acid sequence defining the Pro 140 derived heavy chain of the 117/P140 antibody - PRO 140-HC -Hole-Cross (SEQ ID NO: 12):

EVQLVESGGGLVKPGGSLRLSCAASGYTFSNYWIGWVRQAPGKGLEWIGDIYPGGNYIRNNEKFKDKTTL SADTSKNTAYLQMNSLKTEDTAVYYCGSSFGSNYVFAWFTYWGQGTLVTVSSASTAAPSVFI FPPSDEQL KSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYACE VTHQGLSSPVTKSFNRGECDKTHTCPPCPAPEFEGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDP EVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPASIEKTISKAKG QPREPQVCTLPPSRDELTKNQVSLSCAVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLVSKLT VDKSRWQQGNVFSCSVLHEALHSHYTQKSLSLSPGK

Amino acid sequence defining the 3BNC117 derived light chain of the 117/P140 antibody - 3BNC117-LC (SEQ ID NO: 5):

Amino acid sequence defining the 3BNC117 derived heavy chain of the 117/P140 antibody - 3BNC1 l7-HC-Knob (SEQ ID NO: 6):

QVQLLQSGAAVTKPGASVRVSCEASGYNIRDYFIHWWRQAPGQGLQWVGWINPKTGQPNNPRQFQGRVSL TRHASWDFDTFSFYMDLKALRSDDTAVYFCARQRSDYWDFDVWGQGTLVTVSSASTKGPSVFPLAPSSKS TSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNH KPSNTKVDKKVEPKSCDKTHTCPPCPAPEFEGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVK

FNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPASIEKTISKAKGQPR EPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDK

SRWQQGNVFSCSVLHEALHSHYTQKSLSLSPGK

128/P 140 antibody:

Amino acid sequence defining the Pro 140 derived light chain of the 128/P 140 antibody - PRO 140- VLCH1 (SEQ ID NO: 11):

DIVMTQSPLSLPVTPGEPASISCRSSQRLLSSYGHTYLHWYLQKPGQSPQLLIYEVSNRFSGVPDRFSGS GSGTDFTLKISRVEAEDVGVYYCSQSTHVPLTFGQGTKVEIKSSASTKGPSVFPLAPSSKSTSGGTAALG CLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDK KVEPKSC Amino acid sequence defining the Pro 140 derived heavy chain of the 128/P 140 antibody - PRO 140-HC -Hole-Cross (SEQ ID NO: 12):

Amino acid sequence defining the PGT128 derived light chain of the 128/P 140 antibody - PGT128-LC (SEQ ID NO: 7):

QSALTQPPSASGSPGQSITISCTGTSNNFVSWYQQHAGKAPKLVIYDVNKRPSGVPDRFSGSKSGNTASL TVSGLQTDDEAVYYCGSLVGNWDVIFGGGTKLTVLGQPKAAPSVTLFPPSSEELQANKATLVCLISDFYP GAVTVAWKADSSPVKAGVETTTPSKQSNNKYAASSYLSLTPEQWKSHRSYSCQVTHEGSTVEKTVAPTEC S Amino acid sequence defining the PGT128 derived heavy chain of the 128/P 140 antibody - PGTl28-HC-Knob (SEQ ID NO:8): QPQLQESGPTLVEASETLSLTCAVSGDSTAACNSFWGWVRQPPGKGLEWVGSLSHCASYWNRGWTYHNPS LKSRLTLALDTPKNLVFLKLNSVTAADTATYYCARFGGEVLRYTDWPKPAWVDLWGRGTLVTVSSASTKG PSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSS LGTQTYICNVNHKPSNTKVDKKVEPKSCDKTHTCPPCPAPEFEGGPSVFLFPPKPKDTLMISRTPEVTCV VVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPASI EKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDG SFFLYSKLTVDKSRWQQGNVFSCSVLHEALHSHYTQKSLSLSPGK

10E8/P140 antibody:

Amino acid sequence defining the Pro 140 derived light chain of the 10E8/P140 antibody - PRO140-VLCH1 (SEQ ID NO: l l):

DIVMTQSPLSLPVTPGEPASISCRSSQRLLSSYGHTYLHWYLQKPGQSPQLLIYEVSNRFSGVPDRFSGS GSGTDFTLKISRVEAEDVGVYYCSQSTHVPLTFGQGTKVEIKSSASTKGPSVFPLAPSSKSTSGGTAALG CLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDK KVEPKSC Amino acid sequence defining the Pro 140 derived heavy chain of the 10E8/P140 antibody - PRO 140-HC -Hole-Cross (SEQ ID NO: 12):

Amino acid sequence defining the 10E8 derived light chain of the 10E8/P140 antibody - 10E8-LC (SEQ ID NO: 9):

YELTQETGVSVALGRTVTITCRGDSLRSHYASWYQKKPGQAPILLFYGKNNRPSGVPDRFSGSASGNRAS

TECS

Amino acid sequence defining the 10E8 derived heavy chain of the 10E8/P140 antibody - 10E8- HC-Knob (SEQ ID NO: 10):

D10E8/R140 antibody

Amino acid sequence defining the PRO 140 derived light chain of the D10E8/R140 antibody - PRO140-VLCH1 (SEQ ID NO: 11):

Amino acid sequence defining the PRO 140 derived heavy chain of the D10E8/R140 antibody - PRO 140-Hole-Cross (SEQ ID NO: 12):

EVQLVESGGGLVKPGGSLRLSCAASGYTFSNYWIGWVRQAPGKGLEWIGDIYPGGNYIRNNEKFKDKTTL SADTSKNTAYLQMNSLKTEDTAVYYCGSSFGSNYVFAWFTYWGQGTLVTVSSASTAAPSVFI FPPSDEQL KSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYACE VTHQGLSSPVTKSFNRGECDKTHTCPPCPAPEFEGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDP EVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPASIEKTISKAKG QPREPQVCTLPPSRDELTKNQVSLSCAVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLVSKLT

VDKSRWQQGNVFSCSVLHEALHSHYTQKSLSLSPGK

Amino acid sequence defining the D10E8 derived light chain of the D10E8/R140 antibody - Al0E8-LC (SEQ ID NO:2l): YELTQETGVSVALGRTVTITCRGDSLRSHYASWYQKKPGQAPILLFYGKNNRPSGVPDRFSGASGNRASL TISGAQAEDDAEYYCSSRDKSGSRLSVFGGGTKLTVLSQPKAAPSVTLFPPSSEELQANKATLVCLISDF YPGAVTVAWKADSSPVKAGVETTTPSKQSNNKYAASSYLSLTPEQWKSHRSYSCQVTHEGSTVEKTVAPT ECS

Amino acid sequence defining the D10E8 derived heavy chain of the D10E8/R140 antibody - l0E8-HC-Knob (SEQ ID NO:22):

151/P140 antibody

Amino acid sequence defining the PRO140 derived light chain of the 151/P140 antibody - PRO140-VLCH1 (SEQ ID NO: 11):

DIVMTQSPLSLPVTPGEPASISCRSSQRLLSSYGHTYLHWYLQKPGQSPQLLIYEVSNRFSGVPDRFSGS GSGTDFTLKISRVEAEDVGVYYCSQSTHVPLTFGQGTKVEIKSSASTKGPSVFPLAPSSKSTSGGTAALG CLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDK KVEPKSC Amino acid sequence defining the PRO140 derived heavy chain of the 151/P140 antibody - PRO 140-Hole-Cross (SEQ ID NO: 12): EVQLVESGGGLVKPGGSLRLSCAASGYTFSNYWIGWVRQAPGKGLEWIGDIYPGGNYIRNNEKFKDKTTL SADTSKNTAYLQMNSLKTEDTAVYYCGSSFGSNYVFAWFTYWGQGTLVTVSSASTAAPSVFI FPPSDEQL KSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYACE VTHQGLSSPVTKSFNRGECDKTHTCPPCPAPEFEGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDP EVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPASIEKTISKAKG QPREPQVCTLPPSRDELTKNQVSLSCAVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLVSKLT VDKSRWQQGNVFSCSVLHEALHSHYTQKSLSLSPGK

Amino acid sequence defining the PGT151 derived light chain of the 151/P140 antibody - PGT151-LC (SEQ ID NO:23): DIVMTQTPLSLSVTPGQPASISCKSSESLRQSNGKTSLYWYRQKPGQSPQLLVFEVSNRFSGVSDRFVGS GSGTDFTLRISRVEAEDVGFYYCMQSKDFPLTFGGGTKVDLKRTVAAPSVFI FPPSDEQLKSGTASVVCL LNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYACEVTHQGLSSPV TKSFNRGEC

Amino acid sequence defining the PGT151 derived heavy chain of the 151/P140 antibody - PGT 151 -HC-Knob (SEQ ID NO:24):

RVQLVESGGGVVQPGKSVRLSCVVSDFPFSKYPMYWVRQAPGKGLEWVAAISGDAWHVVYSNSVQGRFLV SRDNVKNTLYLEMNSLKIEDTAVYRCARMFQESGPPRLDRWSGRNYYYYSGMDVWGQGTTVTVSSASTKG PSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSS LGTQTYICNVNHKPSNTKVDKKVEPKSCDKTHTCPPCPAPEFEGGPSVFLFPPKPKDTLMISRTPEVTCV VVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPASI EKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDG SFFLYSKLTVDKSRWQQGNVFSCSVLHEALHSHYTQKSLSLSPGK lOE8/Alpha-Her2 antibody:

Amino acid sequence defining the alpha-Her2 derived light chain of the lOE8/Alpha-Her2 antibody - antiHer2-VLCHl (SEQ ID NO: 13):

DIVMTQSHKFMSTSVGDRVSITCKASQDVNTAVAWYQQKPGHSPKLLIYSASFRYTGVPDRFTGNRSGTD FTFTISSVQAEDLAVYYCQQHYTTPPTFGGGTKVEIKSSASTKGPSVFPLAPSSKSTSGGTAALGCLVKD YFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDKKVEPK SC

Amino acid sequence defining the alpha-Her2 derived heavy chain of the lOE8/Alpha-Her2 antibody - antiHer2-HC -Hole-Cross (SEQ ID NO: 14):

QVQLQQSGPELVKPGASLKLSCTASGFNIKDTYIHWVKQRPEQGLEWIGRIYPTNGYTRYDPKFQDKATI TADTSSNTAYLQVSRLTSEDTAVYYCSRWGGDGFYAMDYWGQGASVTVSSASTAAPSVFI FPPSDEQLKS GTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYACEVT HQGLSSPVTKSFNRGECDKTHTCPPCPAPEFEGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEV KFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPASIEKTISKAKGQP REPQVCTLPPSRDELTKNQVSLSCAVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLVSKLTVD KSRWQQGNVFSCSVLHEALHSHYTQKSLSLSPGK

Amino acid sequence defining the 10E8 derived light chain of the lOE8/Alpha-Her2 antibody - 10E8-LC (SEQ ID NO: 9):

YELTQETGVSVALGRTVTITCRGDSLRSHYASWYQKKPGQAPILLFYGKNNRPSGVPDRFSGSASGNRAS

LTISGAQAEDDAEYYCSSRDKSGSRLSVFGGGTKLTVLSQPKAAPSVTLFPPSSEELQANKATLVCLISD

FYPGAVTVAWKADSSPVKAGVETTTPSKQSNNKYAASSYLSLTPEQWKSHRSYSCQVTHEGSTVEKTVAP

TECS

Amino acid sequence defining the 10E8 derived heavy chain of the lOE8/Alpha-Her2 antibody - l0E8-HC-Knob (SEQ ID NO: 10):

4E10/P140 antibody: Amino acid sequence defining the Pro 140 derived light chain of the 4E10/P140 antibody - PRO140-VLCH1 (SEQ ID NO: 11):

Amino acid sequence defining the Pro 140 derived heavy chain of the 4E10/P140 antibody - PRO 140-HC -Hole-Cross (SEQ ID NO: 12):

Amino acid sequence defining the 4E10 derived light chain of the 4E10/P140 antibody - 4E10-LC (SEQ ID NO: 17):

EIVLTQSPGTQSLSPGERATLSCRASQSVGNNKLAWYQQRPGQAPRLLIYGASSRPSGVADRFSGSGSGT DFTLTISRLEPEDFAVYYCQQYGQSLSTFGQGTKVEVKRTVAAPSVFI FPPSDEQLKSGTASVVCLLNNF YPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYACEVTHQGLSSPVTKSF NRGEC

Amino acid sequence defining the 4E10 derived heavy chain of the 4E10/P140 antibody - PGTl45-HC-Knob (SEQ ID NO: 18):

QVQLVQSGAEVKRPGSSVTVSCKASGGSFSTYALSWVRQAPGRGLEWMGGVIPLLTITNYAPRFQGRITI TADRSTSTAYLELNSLRPEDTAVYYCAREGTTGAGWLGKPIGAFAHWGQGTLVTVSSASTKGPSVFPLAP SSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYIC NVNHKPSNTKVDKKVEPKSCDKTHTCPPCPAPEFEGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHED PEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPASIEKTISKAK GQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKL TVDKSRWQQGNVFSCSVLHEALHSHYTQKSLSLSPGK

10E8/X19 antibody: Amino acid sequence defining the X19 derived light chain of the 10E8/X19 antibody - X19- VLCH1 (SEQ ID NO: 19):

EIVLTQSPATLSVSPGRRATLSCRASQSVNTNLAWYQQKPGQAPRLLIYGASSRATGIPDRFSGSGSGTD FTLTISRLEPEDFAVYYCQHYGSSPLTFGGGTKLEIKSSASTKGPSVFPLAPSSKSTSGGTAALGCLVKD YFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDKKVEPK

sc

Amino acid sequence defining the X19 derived heavy chain of the 10E8/X19 antibody - X19-HC- Hole-Cross (SEQ ID NO:20):

QVQLVQSGGGVVQPGRSLRLSCAASGFTFSSYPMHWVRQAPGKGLEWMTVISSDGRNKYYPDSVKGRFTI SRDNSKNTLYLQMNSLRPEDTAVYYCARGGYHDFWSGPDYWGQGTLVTVSSASTAAPSVFIFPPSDEQLK SGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYACEV THQGLSSPVTKSFNRGECDKTHTCPPCPAPEFEGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPE VKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPASIEKTISKAKGQ PREPQVCTLPPSRDELTKNQVSLSCAVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLVSKLTV DKSRWQQGNVFSCSVLHEALHSHYTQKSLSLSPGK Amino acid sequence defining the 10E8 derived light chain of the 10E8/X19 antibody - 10E8-LC (SEQ ID NO: 9):

YELTQETGVSVALGRTVTITCRGDSLRSHYASWYQKKPGQAPILLFYGKNNRPSGVPDRFSGSASGNRAS LTISGAQAEDDAEYYCSSRDKSGSRLSVFGGGTKLTVLSQPKAAPSVTLFPPSSEELQANKATLVCLISD FYPGAVTVAWKADSSPVKAGVETTTPSKQSNNKYAASSYLSLTPEQWKSHRSYSCQVTHEGSTVEKTVAP TECS Amino acid sequence defining the 10E8 derived heavy chain of the 10E8/X19 antibody - PGT145- HC-Knob (SEQ ID NO: 10):

10E8/515H7 antibody

Amino acid sequence defining the 515H7 derived light chain of the 10E8/515H7 antibody - 515H7-VLCH1 (SEQ ID NO:25):

DIVMSQSPSSLAVSAGEKVTMSCKSSQSLFNSRTRKNYLAWYQQKPGQSPKLLIYWASARDSGVPARFTG SGSETYFTLTISRVQAEDLAVYYCMQSFNLRTFGGGTKLEIKASTKGPSVFPLAPSSKSTSGGTAALGCL VKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDKKV EPKSC

Amino acid sequence defining the 515H7 derived heavy chain of the 10E8/515H7 antibody - 515H7 -Hole-Cross (SEQ ID NO:26):

EVNLVESGGGLVQPGGSLRLSCATSGFTFTDNYMSWVRQPPGKALEWLGFIRNKANGYTTDYSASVRGRF TISRDNSQSILYLQMNALRAEDSATYYCARDVGSNYFDYWGQGTTLTVSSASTAAPSVFI FPPSDEQLKS GTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYACEVT HQGLSSPVTKSFNRGECDKTHTCPPCPAPEFEGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEV KFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPASIEKTISKAKGQP REPQVCTLPPSRDELTKNQVSLSCAVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLVSKLTVD KSRWQQGNVFSCSVLHEALHSHYTQKSLSLSPGK Amino acid sequence defining the 10E8 derived light chain of the 10E8/515H7 antibody - 10E8- LC (SEQ ID NO:9):

YELTQETGVSVALGRTVTITCRGDSLRSHYASWYQKKPGQAPILLFYGKNNRPSGVPDRFSGSASGNRAS

LTISGAQAEDDAEYYCSSRDKSGSRLSVFGGGTKLTVLSQPKAAPSVTLFPPSSEELQANKATLVCLISD

FYPGAVTVAWKADSSPVKAGVETTTPSKQSNNKYAASSYLSLTPEQWKSHRSYSCQVTHEGSTVEKTVAP

TECS

Amino acid sequence defining the 10E8 derived heavy chain of the 10E8/515H7 antibody - 10E8- HC-Knob (SEQ ID NO: 10):

Chimeric CDR123 antibody (SEQ ID NO:27):

SELTQDPAVSVALGQTVRITCRGDSLRSHYASWYQQKPGQAPVLVIYGKNNRPSGIPDRFSGSSSGNTAS

LTITGAQAEDEADYYCSSRDKSGSRLSVFGGGTKLTVLSQPKAAPSVTLFPPSSEELQANKATLVCLISD

FYPGAVTVAWKADSSPVKAGVETTTPSKQSNNKYAASSYLSLTPEQWKSHRSYSCQVTHEGSTVEKTVAP

TECS

Chimeric FW123 (SEQ ID NO:28):

YELTQETGVSVALGRTVTITCQGDSLRSYYASWYQKKPGQAPILLFYGKNNRPSGVPDRFSGSASGNRAS

LTISGAQAEDDAEYYCNSRDSSGNHLVVFGGGTKLTVLSQPKAAPSVTLFPPSSEELQANKATLVCLISD

FYPGAVTVAWKADSSPVKAGVETTTPSKQSNNKYAASSYLSLTPEQWKSHRSYSCQVTHEGSTVEKTVAP

TECS !0E8Vl.0/iMab antibody

Amino acid sequence defining the MV1 derived light chain of the l0E8vl.0/MVl antibody MV1- VLCH1 (SEQ ID NO: l):

DIVMTQSPDSLAVSLGERVTMNCKSSQSLLYSTNQKNYLAWYQQKPGQSPKLLIYWASTRESGVPDRFSG SGSGTDFTLTISSVQAEDVAVYYCQQYYSYRTFGGGTKLEIKSSASTKGPSVFPLAPSSKSTSGGTAALG

CLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDK KVEPKSC

Amino acid sequence defining the MV1 derived heavy chain of the l0E8vl.0/MVl antibody MV 1 -HC -Hole-Cross (SEQ ID NO:2): QVQLQQSGPEVVKPGASVKMSCKASGYTFTSYVIHWVRQKPGQGLDWIGYINPYNDGTDYDEKFKGKATL TSDTSTSTAYMELSSLRSEDTAVYYCAREKDNYATGAWFAYWGQGTLVTVSSASTAAPSVFI FPPSDEQL KSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYACE VTHQGLSSPVTKSFNRGECDKTHTCPPCPAPEFEGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDP EVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPASIEKTISKAKG QPREPQVCTLPPSRDELTKNQVSLSCAVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLVSKLT VDKSRWQQGNVFSCSVLHEALHSHYTQKSLSLSPGK

Amino acid sequence defining the lOE8vl.O derived light chain of the l0E8vl .0/iMab antibody - l0E8vl.0-LC (SEQ ID NO:29):

ASELTQDPAVSVALKQTVTITCRGDSLRSHYVSWYQKKPGQAPVLVFYGKNNRPSGIPDRFSGSSSGNTA SLTIAGAQAEDDADYYCSSRDKSGSRLSVFGGGTKLTVLSQPKAAPSVTLFPPSSEELQANKATLVCLIS DFYPGAVTVAWKADSSPVKAGVETTTPSKQSNNKYAASSYLSLTPEQWKSHRSYSCQVTHEGSTVEKTVA PTECS

Amino acid sequence defining the lOE8vl.O derived heavy chain of the l0E8vl.0/iMab antibody - 10E8v 1.0-HC-Knob (SEQ ID NO:30): EVRLVESGGGLVKPGGSLRLSCSASGFNFDDAWMTWVRQPPGKGLEWVGRISGPGEGWSVDYAESVKGRF TISRLNSINFLYLEMNNVRTEDTGYYFCARTGKHYDFWSGYPPGEEYFQDWGQGTLVIVSSASTKGPSVF PLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQ TYICNVNHKPSNTKVDKKVEPKSCDKTHTCPPCPAPEFEGGPSVFLFPPKPKDTLMISRTPEVTCVVVDV SHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPASIEKTI SKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFL YSKLTVDKSRWQQGNVFSCSVLHEALHSHYTQKSLSLSPGK lOE8Vl.l/iMab antibody

Amino acid sequence defining the MVl derived light chain of the l0E8vl. l/iMab antibody MV1- VLCH1 (SEQ ID NO: l):

Amino acid sequence defining the MV1 derived heavy chain of the l0E8vl.l/iMab antibody MV 1 -HC -Hole-Cross (SEQ ID NO:2): QVQLQQSGPEVVKPGASVKMSCKASGYTFTSYVIHWVRQKPGQGLDWIGYINPYNDGTDYDEKFKGKATL TSDTSTSTAYMELSSLRSEDTAVYYCAREKDNYATGAWFAYWGQGTLVTVSSASTAAPSVFI FPPSDEQL KSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYACE VTHQGLSSPVTKSFNRGECDKTHTCPPCPAPEFEGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDP EVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPASIEKTISKAKG QPREPQVCTLPPSRDELTKNQVSLSCAVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLVSKLT VDKSRWQQGNVFSCSVLHEALHSHYTQKSLSLSPGK

Amino acid sequence defining the l0E8vl.l derived light chain of the l0E8vl. l/iMab antibody - l0E8vl.l-LC (SEQ ID NO:3 l):

ASELTQDPAVSVALKQTVTITCRGDSLRSHYVSWYQKKPGQAPVLVFYGKNNRPSGIPDRFSGSSSGNTA SLTIAGAQAEDDADYYCSSRDKSGSRLSVFGGGTKLTVLSQPKAAPSVTLFPPSSEELQANKATLVCLIS DFYPGAVTVAWKADSSPVKAGVETTTPSKQSNNKYAASSYLSLTPEQWKSHRSYSCQVTHEGSTVEKTVA

PTECS Amino acid sequence defining the lOE8vl.l derived heavy chain of the lOE8vl. l/iMab antibody - l0E8vl.l HC-Knob (SEQ ID NO:32):

EVRLVESGGGLVKPGGSLRLSCSASGFNFDDAWMTWVRQPPGKGLEWVGRISGPGEGWSVDYAESVKGRF TISRLNSINFLYLEMNNVRTEDTGYYFCARTGKYYDFWSGYPPGEEYFQDWGQGTLVIVSSASTKGPSVF PLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQ

TYICNVNHKPSNTKVDKKVEPKSCDKTHTCPPCPAPEFEGGPSVFLFPPKPKDTLMISRTPEVTCVVVDV SHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPASIEKTI SKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFL YSKLTVDKSRWQQGNVFSCSVLHEALHSHYTQKSLSLSPGK l0E8V2.0/iMab antibody (also referred to as lOE8.2/iMab antibody)

Amino acid sequence defining the MV1 derived light chain of the l0E8v2.0/iMab antibody MV1- VLCH1 (SEQ ID NO: 1):

Amino acid sequence defining the MV1 derived heavy chain of the l0E8v2.0/iMab antibody MV 1 -HC -Hole-Cross (SEQ ID NO:2):

QVQLQQSGPEVVKPGASVKMSCKASGYTFTSYVIHWVRQKPGQGLDWIGYINPYNDGTDYDEKFKGKATL TSDTSTSTAYMELSSLRSEDTAVYYCAREKDNYATGAWFAYWGQGTLVTVSSASTAAPSVFI FPPSDEQL KSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYACE VTHQGLSSPVTKSFNRGECDKTHTCPPCPAPEFEGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDP EVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPASIEKTISKAKG QPREPQVCTLPPSRDELTKNQVSLSCAVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLVSKLT VDKSRWQQGNVFSCSVLHEALHSHYTQKSLSLSPGK Amino acid sequence defining the 10E8n2.0 derived light chain of the l0E8v2.0/iMab antibody - l0E8v2.0-LC (SEQ ID NO:33):

ASELTQDPAVSVALKQTVTITCRGDSLRSHYASWYQKKPGQAPILLFYGKNNRPSGVPDRFSGSASGNRA SLTISGAQAEDDAEYYCSSRDKSGSRLSVFGGGTKLTVLSQPKAAPSVTLFPPSSEELQANKATLVCLIS DFYPGAVTVAWKADSSPVKAGVETTTPSKQSNNKYAASSYLSLTPEQWKSHRSYSCQVTHEGSTVEKTVA PTECS

Amino acid sequence defining the 10E8n2.0 derived heavy chain of the l0E8v2.0/iMab antibody - 10E8v2.0-HC-Knob (SEQ ID NO:34):

EVRLVESGGGLVKPGGSLRLSCSASGFNFDDAWMTWVRQPPGKGLEWVGRISGPGEGWSVDYAESVKGRF TISRLNSINFLYLEMNNVRTEDTGYYFCARTGKHYDFWSGYPPGEEYFQDWGQGTLVIVSSASTKGPSVF PLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQ TYICNVNHKPSNTKVDKKVEPKSCDKTHTCPPCPAPEFEGGPSVFLFPPKPKDTLMISRTPEVTCVVVDV SHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPASIEKTI SKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFL YSKLTVDKSRWQQGNVFSCSVLHEALHSHYTQKSLSLSPGK l0E8V3.0/iMab antibody

Amino acid sequence defining the MV1 derived light chain of the l0E8v3.0/iMab antibody MV1- VLCH1 (SEQ ID NO: 1):

Amino acid sequence defining the MV1 derived heavy chain of the l0E8v3.0/iMab antibody MV 1 -HC -Hole-Cross (SEQ ID NO:2): QVQLQQSGPEVVKPGASVKMSCKASGYTFTSYVIHWVRQKPGQGLDWIGYINPYNDGTDYDEKFKGKATL TSDTSTSTAYMELSSLRSEDTAVYYCAREKDNYATGAWFAYWGQGTLVTVSSASTAAPSVFI FPPSDEQL KSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYACE VTHQGLSSPVTKSFNRGECDKTHTCPPCPAPEFEGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDP EVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPASIEKTISKAKG QPREPQVCTLPPSRDELTKNQVSLSCAVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLVSKLT VDKSRWQQGNVFSCSVLHEALHSHYTQKSLSLSPGK

Amino acid sequence defining the 10E8n3.0 derived light chain of the l0E8v3.0/iMab antibody - l0E8v3.0-LC (SEQ ID NO: 15):

SELTQETGVSVALGRTVTITCRGDSLRSHYASWYQKKPGQAPILLFYGKNNRPSGIHDRFSGSASGNRAS

LTISGAQAEDDAEYYCSSRDKSGSRLSVFGGGTKLTVLSQPKAAPSVTLFPPSSEELQANKATLVCLISD

FYPGAVTVAWKADSSPVKAGVETTTPSKQSNNKYAASSYLSLTPEQWKSHRSYSCQVTHEGSTVEKTVAP

TECS

Amino acid sequence defining the 10E8n3.0 derived heavy chain of the l0E8v3.0/iMab antibody - 10E8v3.0-HC-Knob (SEQ ID NO:l6):

EVQLVESGGDLVKPGGSLRLSCSASGFSFKNTWMTWVRQAPGKGLEWVGRITGPGEGWTSDYAATVQGRF TISRNNMIDMLYLEMNRLRTDDTGLYYCVHTEKYYNFWGGYPPGEEYFQHWGRGTLVIVSSASTKGPSVF PLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQ TYICNVNHKPSNTKVDKKVEPKSCDKTHTCPPCPAPEFEGGPSVFLFPPKPKDTLMISRTPEVTCVVVDV SHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPASIEKTI SKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFL YSKLTVDKSRWQQGNVFSCSVLHEALHSHYTQKSLSLSPGK

10E8V1.0/P140 (H6L10/PR0140) antibody

Amino acid sequence defining the PRO140 derived light chain of the 10E8V1.0/P140 antibody - PRO140-VLCH1 (SEQ ID NO: 11):

KVEPKSC Amino acid sequence defining the PRO140 derived heavy chain of the 10E8V1.0/P140 antibody - PRO 140-Hole-Cross (SEQ ID NO: 12):

EVQLVESGGGLVKPGGSLRLSCAASGYTFSNYWIGWVRQAPGKGLEWIGDIYPGGNYIRNNEKFKDKTTL SADTSKNTAYLQMNSLKTEDTAVYYCGSSFGSNYVFAWFTYWGQGTLVTVSSASTAAPSVFI FPPSDEQL KSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYACE

VTHQGLSSPVTKSFNRGECDKTHTCPPCPAPEFEGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDP EVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPASIEKTISKAKG QPREPQVCTLPPSRDELTKNQVSLSCAVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLVSKLT VDKSRWQQGNVFSCSVLHEALHSHYTQKSLSLSPGK Amino acid sequence defining the L10 derived light chain of the 10E8V1.0/P140 antibody - L10- LC (SEQ ID NO:29):

Amino acid sequence defining the H6 derived heavy chain of the 10E8V1.0/P140 antibody - H6- HC-Knob (SEQ ID NO:30):

EVRLVESGGGLVKPGGSLRLSCSASGFNFDDAWMTWVRQPPGKGLEWVGRISGPGEGWSVDYAESVKGRF TISRLNSINFLYLEMNNVRTEDTGYYFCARTGKHYDFWSGYPPGEEYFQDWGQGTLVIVSSASTKGPSVF PLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQ TYICNVNHKPSNTKVDKKVEPKSCDKTHTCPPCPAPEFEGGPSVFLFPPKPKDTLMISRTPEVTCVVVDV SHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPASIEKTI SKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFL YSKLTVDKSRWQQGNVFSCSVLHEALHSHYTQKSLSLSPGK 10E8V1.1/P140 antibody Amino acid sequence defining the PRO140 derived light chain of the 10E8n1.1/R140 antibody PRO140-VLCH1 (SEQ ID NO: 11):

Amino acid sequence defining the P140 derived heavy chain of the 10E8n1.1/R140 antibody PRO 140-HC -Hole-Cross (SEQ ID NO: 12):

Amino acid sequence defining the l0E8vl.l derived light chain of the 10E8n1.1/R140 antibody - l0E8vl.l-LC (SEQ ID NO:3 l):

Amino acid sequence defining the l0E8vl.l derived heavy chain of the 10E8n1.1/R140 antibody - l0E8vl.l HC-Knob (SEQ ID NO:32):

EVRLVESGGGLVKPGGSLRLSCSASGFNFDDAWMTWVRQPPGKGLEWVGRISGPGEGWSVDYAESVKGRF TISRLNSINFLYLEMNNVRTEDTGYYFCARTGKYYDFWSGYPPGEEYFQDWGQGTLVIVSSASTKGPSVF PLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQ TYICNVNHKPSNTKVDKKVEPKSCDKTHTCPPCPAPEFEGGPSVFLFPPKPKDTLMISRTPEVTCVVVDV SHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPASIEKTI

SKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFL

YSKLTVDKSRWQQGNVFSCSVLHEALHSHYTQKSLSLSPGK

10E8V2.0/P140 antibody Amino acid sequence defining the PRO140 derived light chain of the 10E8n2.0/R140 antibody PRO140-VLCH1 (SEQ ID NO: 11):

Amino acid sequence defining the P140 derived heavy chain of the 10E8n2.0/R140 antibody PRO 140-HC -Hole-Cross (SEQ ID NO: 12):

EVQLVESGGGLVKPGGSLRLSCAASGYTFSNYWIGWVRQAPGKGLEWIGDIYPGGNYIRNNEKFKDKTTL SADTSKNTAYLQMNSLKTEDTAVYYCGSSFGSNYVFAWFTYWGQGTLVTVSSASTAAPSVFI FPPSDEQL KSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYACE VTHQGLSSPVTKSFNRGECDKTHTCPPCPAPEFEGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDP EVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPASIEKTISKAKG QPREPQVCTLPPSRDELTKNQVSLSCAVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLVSKLT VDKSRWQQGNVFSCSVLHEALHSHYTQKSLSLSPGK Amino acid sequence defining the 10E8n2.0 derived light chain of the 10E8n2.0/R140 antibody - l0E8v2.0-LC (SEQ ID NO:33):

ASELTQDPAVSVALKQTVTITCRGDSLRSHYASWYQKKPGQAPILLFYGKNNRPSGVPDRFSGSASGNRA SLTISGAQAEDDAEYYCSSRDKSGSRLSVFGGGTKLTVLSQPKAAPSVTLFPPSSEELQANKATLVCLIS DFYPGAVTVAWKADSSPVKAGVETTTPSKQSNNKYAASSYLSLTPEQWKSHRSYSCQVTHEGSTVEKTVA PTECS Amino acid sequence defining the 10E8n2.0 derived heavy chain of the 10E8n2.0/R140 antibody - 10E8n2.0 HC-Knob (SEQ ID NO:34):

EVRLVESGGGLVKPGGSLRLSCSASGFNFDDAWMTWVRQPPGKGLEWVGRISGPGEGWSVDYAESVKGRF TISRLNSINFLYLEMNNVRTEDTGYYFCARTGKHYDFWSGYPPGEEYFQDWGQGTLVIVSSASTKGPSVF PLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQ TYICNVNHKPSNTKVDKKVEPKSCDKTHTCPPCPAPEFEGGPSVFLFPPKPKDTLMISRTPEVTCVVVDV SHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPASIEKTI SKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFL YSKLTVDKSRWQQGNVFSCSVLHEALHSHYTQKSLSLSPGK 10E8V3.0/P140 antibody

Amino acid sequence defining the PRO 140 derived light chain of the 10E8n3.0/R140 antibody PRO140-VLCH1 (SEQ ID NO: 11):

Amino acid sequence defining the P140 derived heavy chain of the 10E8n3.0/R140 antibody PRO 140-HC -Hole-Cross (SEQ ID NO: 12):

EVQLVESGGGLVKPGGSLRLSCAASGYTFSNYWIGWVRQAPGKGLEWIGDIYPGGNYIRNNEKFKDKTTL SADTSKNTAYLQMNSLKTEDTAVYYCGSSFGSNYVFAWFTYWGQGTLVTVSSASTAAPSVFI FPPSDEQL KSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYACE VTHQGLSSPVTKSFNRGECDKTHTCPPCPAPEFEGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDP EVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPASIEKTISKAKG QPREPQVCTLPPSRDELTKNQVSLSCAVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLVSKLT VDKSRWQQGNVFSCSVLHEALHSHYTQKSLSLSPGK Amino acid sequence defining the 10E8n3.0 derived light chain of the 10E8n3.0/R140 antibody - l0E8v3.0-LC (SEQ ID NO: 15):

SELTQETGVSVALGRTVTITCRGDSLRSHYASWYQKKPGQAPILLFYGKNNRPSGIHDRFSGSASGNRAS

LTISGAQAEDDAEYYCSSRDKSGSRLSVFGGGTKLTVLSQPKAAPSVTLFPPSSEELQANKATLVCLISD

FYPGAVTVAWKADSSPVKAGVETTTPSKQSNNKYAASSYLSLTPEQWKSHRSYSCQVTHEGSTVEKTVAP

TECS

Amino acid sequence defining the 10E8n3.0 derived heavy chain of the 10E8n3.0/R140 antibody - 10E8n3.0 HC-Knob (SEQ ID NO: 16):

EVQLVESGGDLVKPGGSLRLSCSASGFSFKNTWMTWVRQAPGKGLEWVGRITGPGEGWTSDYAATVQGRF TISRNNMIDMLYLEMNRLRTDDTGLYYCVHTEKYYNFWGGYPPGEEYFQHWGRGTLVIVSSASTKGPSVF PLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQ TYICNVNHKPSNTKVDKKVEPKSCDKTHTCPPCPAPEFEGGPSVFLFPPKPKDTLMISRTPEVTCVVVDV SHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPASIEKTI SKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFL YSKLTVDKSRWQQGNVFSCSVLHEALHSHYTQKSLSLSPGK lOE8.2. l/iMab

Amino acid sequence defining the MV1 derived light chain of the lOE8.2/iMab antibody MV1- VLCH1 (SEQ ID NO: 1)

Amino acid sequence defining the MV1 derived heavy chain of the lOE8.2/iMab antibody MV1- HC-Hole-Cross (SEQ ID NO: 2)

QVQLQQSGPEVVKPGASVKMSCKASGYTFTSYVIHWVRQKPGQGLDWIGYINPYNDGTDYDEKFKGKATL TSDTSTSTAYMELSSLRSEDTAVYYCAREKDNYATGAWFAYWGQGTLVTVSSASTAAPSVFI FPPSDEQL KSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYACE VTHQGLSSPVTKSFNRGECDKTHTCPPCPAPEFEGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDP

EVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPASIEKTISKAKG

QPREPQVCTLPPSRDELTKNQVSLSCAVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLVSKLT

VDKSRWQQGNVFSCSVLHEALHSHYTQKSLSLSPGK

Amino acid sequence defining the 10E8.2 derived light chain of the lOE8.2/iMab antibody - 10E8.2-LC (SEQ ID NO: 33)

Amino acid sequence defining the 10E8.2.1 derived heavy chain of the lOE8.2.l/iMab antibody - 10E 8.2.1 -HC -Knob (SEQ ID NO:35)

EVRLVESGGGLVKPGGSLRLSCSASGFNFDDAWMTWVRQPPGKGLEWVGRISGPGEGWSVDYAESVKGRF TISRDNTKNTLYLEMNNVRTEDTGYYFCARTGKHYDFWSGYPPGEEYFQDWGQGTLVIVSSASTKGPSVF PLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQ TYICNVNHKPSNTKVDKKVEPKSCDKTHTCPPCPAPEFEGGPSVFLFPPKPKDTLMISRTPEVTCVVVDV SHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPASIEKTI SKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFL YSKLTVDKSRWQQGNVFSCSVLHEALHSHYTQKSLSLSPGK lOE8.2.2/iMab

Amino acid sequence defining the MV1 derived heavy chain of the lOE8.2/iMab antibody MV1- HC-Hole-Cross (SEQ ID NO: 2) QVQLQQSGPEVVKPGASVKMSCKASGYTFTSYVIHWVRQKPGQGLDWIGYINPYNDGTDYDEKFKGKATL TSDTSTSTAYMELSSLRSEDTAVYYCAREKDNYATGAWFAYWGQGTLVTVSSASTAAPSVFI FPPSDEQL KSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYACE VTHQGLSSPVTKSFNRGECDKTHTCPPCPAPEFEGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDP EVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPASIEKTISKAKG QPREPQVCTLPPSRDELTKNQVSLSCAVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLVSKLT VDKSRWQQGNVFSCSVLHEALHSHYTQKSLSLSPGK

Amino acid sequence defining the 10E8.2.2 derived heavy chain of the lOE8.2.2/iMab antibody - lOE8.2.2-HC-Knob (SEQ ID NO:36)

EVRLVESGGGLVKPGGSLRLSCSASGFNFDDAWMTWVRQPPGKGLEWVGRISGPGEGWSVDYAESVKGRF TISRLNSINFLYLEMNNVRTEDTGYYFCARTGKHYDFWSGYPPGEEYFQDWGQGTKVIVSSASTKGPSVF PLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQ TYICNVNHKPSNTKVDKKVEPKSCDKTHTCPPCPAPEFEGGPSVFLFPPKPKDTLMISRTPEVTCVVVDV SHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPASIEKTI SKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFL YSKLTVDKSRWQQGNVFSCSVLHEALHSHYTQKSLSLSPGK lOE8.2.3/iMab

DIVMTQSPDSLAVSLGERVTMNCKSSQSLLYSTNQKNYLAWYQQKPGQSPKLLIYWASTRESGVPDRFSG SGSGTDFTLTISSVQAEDVAVYYCQQYYSYRTFGGGTKLEIKSSASTKGPSVFPLAPSSKSTSGGTAALG CLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDK

KVEPKSC Amino acid sequence defining the MV1 derived heavy chain of the lOE8.2/iMab antibody MV1- HC-Hole-Cross (SEQ ID NO: 2)

Amino acid sequence defining the 10E8.2.3 derived heavy chain of the lOE8.2.3/iMab antibody - 10E 8.2.3 -HC -Knob (SEQ ID NO:37)

EVRLVESGGGLVKPGGSLRLSCSASGFNFDDAWMTWVRQPPGKGLEWVGRISGPGEGWSVDYAESVKGRF TISRDNTKNTLYLEMNNVRTEDTGYYFCARTGKHYDFWSGYPPGEEYFQDWGQGT KVIVSSASTKGPSVF PLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQ TYICNVNHKPSNTKVDKKVEPKSCDKTHTCPPCPAPEFEGGPSVFLFPPKPKDTLMISRTPEVTCVVVDV SHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPASIEKTI SKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFL YSKLTVDKSRWQQGNVFSCSVLHEALHSHYTQKSLSLSPGK lOE8.2.4/iMab

Amino acid sequence defining the MV1 derived light chain of the lOE8.2.4/iMab antibody MV1-VLCH1-LM52 (SEQ ID NO:38) DIVMTQSPDSLAVSLGERVTMNCKSSQSLLYSTNQKNYLAWYQQKPGQSPKLLIYWANSTESGVPDRFSG SGSGTDFTLTISSVQAEDVAVYYCQQYYSYRTFGGGTKLEIKSSASTKGPSVFPLAPSSKSTSGGTAALG CLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDK KVEPKSC

Amino acid sequence defining the 10E8.2.3 derived heavy chain of the lOE8.2.3/iMab antibody - 10E 8.2.3 -HC -Knob (SEQ ID NO:39)

EVRLVESGGGLVKPGGSLRLSCSASGFNFDDAWMTWVRQPPGKGLEWVGRISGPGEGWSVDYAESVKGRF TISRDNTKNTLYLEMNNVRTEDTGYYFCARTGKHYDFWSGYPPGEEYFQDWGQGTKVIVSSASTKGPSVF PLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQ TYICNVNHKPSNTKVDKKVEPKSCDKTHTCPPCPAPEFEGGPSVFLFPPKPKDTLMISRTPEVTCVVVDV SHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPASIEKTI SKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFL YSKLTVDKSRWQQGNVFSCSVLHEALHSHYTQKSLSLSPGK !0E8.2.5/iMab

Amino acid sequence defining the 10E8.2.5 derived heavy chain of the 10E8.2.5 /iMab antibody - 10E8.2.5 -HC-Knob (SEQ ID NO:40)

EVRLVESGGGLVKPGGSLRLSCSASGFNFDDAWMTWVRQPPGKGLEWVGRISGPGEGWSVDYAESVKGRF TISRKNSINTLYLEMNNVRTEDTGYYFCARTGKHYDFWSGYPPGEEYFQDWGQGTKVIVSSASTKGPSVF PLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQ

TYICNVNHKPSNTKVDKKVEPKSCDKTHTCPPCPAPEFEGGPSVFLFPPKPKDTLMISRTPEVTCVVVDV SHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPASIEKTI

SKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFL

YSKLTVDKSRWQQGNVFSCSVLHEALHSHYTQKSLSLSPGK lOE8.2.6/iMab

Amino acid sequence defining the 10E8.2.6 derived heavy chain of the lOE8.2.6/iMab antibody - lOE8.2.6-HC-Knob (SEQ ID NO:4l) EVRLVESGGGLVKPGGSLRLSCSASGFNFDDAWMTWVRQPPGKGLEWVGRISGPGEGWSVDYAESVKGRF TISRDNSINTLYLEMNNVRTEDTGYYFCARTGKHYDFWSGYPPGEEYFQDWGQGTKVIVSSASTKGPSVF PLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQ TYICNVNHKPSNTKVDKKVEPKSCDKTHTCPPCPAPEFEGGPSVFLFPPKPKDTLMISRTPEVTCVVVDV SHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPASIEKTI SKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFL YSKLTVDKSRWQQGNVFSCSVLHEALHSHYTQKSLSLSPGK lOE8.2.7/iMab

ASELTQDPAVSVALKQTVTITCRGDSLRSHYASWYQKKPGQAPILLFYGKNNRPSGVPDRFSGSASGNRA SLTISGAQAEDDAEYYCSSRDKSGSRLSVFGGGTKLTVLSQPKAAPSVTLFPPSSEELQANKATLVCLIS DFYPGAVTVAWKADSSPVKAGVETTTPSKQSNNKYAASSYLSLTPEQWKSHRSYSCQVTHEGSTVEKTVA

PTECS Amino acid sequence defining the 10E8.4 derived heavy chain of the lOE8.4/iMab antibody - lOE8.4-HC-Knob (SEQ ID NO:42)

EVRLVESGGGLVKPGGSLRLSCSASGFNFDDAWMTWVRQPPGKGLEWVGRISGPGEGWSVDYAESVKGRF TISRKNSKNTLYLEMNNVRTEDTGYYFCARTGKHYDFWSGYPPGEEYFQDWGQGTKVIVSSASTKGPSVF PLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQ TYICNVNHKPSNTKVDKKVEPKSCDKTHTCPPCPAPEFEGGPSVFLFPPKPKDTLMISRTPEVTCVVVDV SHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPASIEKTI SKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFL YSKLTVDKSRWQQGNVFSCSVLHEALHSHYTQKSLSLSPGK lOE8.2.8/iMab

Amino acid sequence defining the 10E8.2 derived light chain of the lOE8.2/iMab antibody - 10E8.2-LC (SEQ ID NO: 33) ASELTQDPAVSVALKQTVTITCRGDSLRSHYASWYQKKPGQAPILLFYGKNNRPSGVPDRFSGSASGNRA SLTISGAQAEDDAEYYCSSRDKSGSRLSVFGGGTKLTVLSQPKAAPSVTLFPPSSEELQANKATLVCLIS DFYPGAVTVAWKADSSPVKAGVETTTPSKQSNNKYAASSYLSLTPEQWKSHRSYSCQVTHEGSTVEKTVA PTECS

Amino acid sequence defining the 10E8.2.8 derived heavy chain of the lOE8.2.8/iMab antibody - 10E 8.2.8 -HC -Knob (SEQ ID NO:43)

EVRLVESGGGLVKPGGSLRLSCSASGFNFDDAWMTWVRQPPGKGLEWVGRISGPGEGWSVDYAESVKGRF TISRDNSKNTLYLEMNNVRTEDTGYYFCARTGKHYDFWSGYPPGEEYFQDWGQGTKVIVSSASTKGPSVF PLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQ TYICNVNHKPSNTKVDKKVEPKSCDKTHTCPPCPAPEFEGGPSVFLFPPKPKDTLMISRTPEVTCVVVDV SHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPASIEKTI SKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFL YSKLTVDKSRWQQGNVFSCSVLHEALHSHYTQKSLSLSPGK lOE8.2. lO/iMab

QVQLQQSGPEVVKPGASVKMSCKASGYTFTSYVIHWVRQKPGQGLDWIGYINPYNDGTDYDEKFKGKATL TSDTSTSTAYMELSSLRSEDTAVYYCAREKDNYATGAWFAYWGQGTLVTVSSASTAAPSVFI FPPSDEQL KSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYACE VTHQGLSSPVTKSFNRGECDKTHTCPPCPAPEFEGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDP EVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPASIEKTISKAKG QPREPQVCTLPPSRDELTKNQVSLSCAVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLVSKLT VDKSRWQQGNVFSCSVLHEALHSHYTQKSLSLSPGK Amino acid sequence defining the 10E8.4 derived light chain of the lOE8.4/iMab antibody - 10E8.4-LC (SEQ ID NO:44)

ASELTQDPAVSVALKQTVTITCRGDSLRSHYASWYQKKTGQAPKLLFYGKNNRPSGVPDRFSGSASGNRA SLTISGAQAEDDAEYYCSSRDKSGSRLSVFGGGTKLTVLSQPKAAPSVTLFPPSSEELQANKATLVCLIS DFYPGAVTVAWKADSSPVKAGVETTTPSKQSNNKYAASSYLSLTPEQWKSHRSYSCQVTHEGSTVEKTVA PTECS

Amino acid sequence defining the 10E8.2.8 derived heavy chain of the lOE8.2.8/iMab antibody - 10E 8.2.8 -HC -Knob (SEQ ID NO:45)

EVRLVESGGGLVKPGGSLRLSCSASGFNFDDAWMTWVRQPPGKGLEWVGRISGPGEGWSVDYAESVKGRF TISRDNSKNTLYLEMNNVRTEDTGYYFCARTGKHYDFWSGYPPGEEYFQDWGQGTKVIVSSASTKGPSVF PLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQ TYICNVNHKPSNTKVDKKVEPKSCDKTHTCPPCPAPEFEGGPSVFLFPPKPKDTLMISRTPEVTCVVVDV SHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPASIEKTI SKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFL YSKLTVDKSRWQQGNVFSCSVLHEALHSHYTQKSLSLSPGK lOE8.4/iMab

QVQLQQSGPEVVKPGASVKMSCKASGYTFTSYVIHWVRQKPGQGLDWIGYINPYNDGTDYDEKFKGKATL TSDTSTSTAYMELSSLRSEDTAVYYCAREKDNYATGAWFAYWGQGTLVTVSSASTAAPSVFI FPPSDEQL KSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYACE VTHQGLSSPVTKSFNRGECDKTHTCPPCPAPEFEGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDP EVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPASIEKTISKAKG

QPREPQVCTLPPSRDELTKNQVSLSCAVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLVSKLT

VDKSRWQQGNVFSCSVLHEALHSHYTQKSLSLSPGK

Amino acid sequence defining the 10E8.4 derived light chain of the lOE8.4/iMab antibody - 10E8.4-LC (SEQ ID NO:46)

Amino acid sequence defining the 10E8.4 derived heavy chain of the lOE8.4/iMab antibody - lOE8.4-HC-Knob (SEQ ID NO:47)

EVRLVESGGGLVKPGGSLRLSCSASGFNFDDAWMTWVRQPPGKGLEWVGRISGPGEGWSVDYAESVKGRF TISRKNSKNTLYLEMNNVRTEDTGYYFCARTGKHYDFWSGYPPGEEYFQDWGQGTKVIVSSASTKGPSVF PLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQ TYICNVNHKPSNTKVDKKVEPKSCDKTHTCPPCPAPEFEGGPSVFLFPPKPKDTLMISRTPEVTCVVVDV SHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPASIEKTI SKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFL YSKLTVDKSRWQQGNVFSCSVLHEALHSHYTQKSLSLSPGK

In various embodiments, at least one of the heavy chain and/or light chain sequences derived from the PGT145, PG9, PGT128, PGT121, 10-1074, 3BNC117, VRC01, PGT151, 4E10, 10E8, P140, iMab (or the MV1 variant), 515H7 antibodies and variants thereof are paired together to form a bispecific antibody ( e.g ., a HIV CrossMab antibody). In an exemplary embodiment, at least one of the disclosed heavy and light chains selected from SEQ ID NOs: 1-36 are paired together to form a bispecific antibody (e.g., a HIV CrossMab antibody).

In various embodiments, the amino acid sequence of the bispecific antibody (e.g, HIV

CrossMab antibody) further includes an amino acid analog, an amino acid derivative, or other non-classical amino acids. In various embodiments, the bispecific antibody ( e.g ., HIV CrossMab antibody) comprises a sequence that is at least 60% identical to a wild-type heavy or light chain sequence of the PGT145, PG9, PGT128, PGT121, 10-1074, 3BNC117, VRC01, PGT151, 4E10, or 10E8 antibody. In various embodiments, the bispecific antibody (e.g., HIV CrossMab antibody) comprises a sequence that is at least 60% identical to a wild-type heavy chain or light chain sequence of the P140, iMab (or the MV1 variant), or 515H7 antibody. In exemplary

embodiments, the bispecific antibody (e.g, HIV CrossMab antibody) comprises a sequence that is at least 60% identical to any of the sequences disclosed herein.

In various embodiments, the bispecific antibody (e.g, HIV CrossMab antibody) may comprise a sequence that is at least about 60%, at least about 61%, at least about 62%, at least about 63%, at least about 64%, at least about 65%, at least about 66%, at least about 67%, at least about 68%, at least about 69%, at least about 70%, at least about 71%, at least about 72%, at least about 73%, at least about 74%, at least about 75%, at least about 76%, at least about 77%, at least about 78%, at least about 79%, at least about 80%, at least about 81%, at least about 82%, at least about 83%, at least about 84%, at least about 85%, at least about 86%, at least about 87%, at least about 88%, at least about 89%, at least about 90%, at least about 91%, at least about 92%, at least about 93%, at least about 94%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identical to a wild-type heavy chain or light chain sequence of the PGT145, PG9, PGT128, PGT121, 10-1074, 3BNC117, VRC01, PGT151, 4E10, or 10E8 antibody.

In various embodiments, the bispecific antibody (e.g, HIV CrossMab antibody) may comprise a sequence that is at least about 60%, at least about 61%, at least about 62%, at least about 63%, at least about 64%, at least about 65%, at least about 66%, at least about 67%, at least about 68%, at least about 69%, at least about 70%, at least about 71%, at least about 72%, at least about 73%, at least about 74%, at least about 75%, at least about 76%, at least about 77%, at least about 78%, at least about 79%, at least about 80%, at least about 81%, at least about 82%, at least about 83%, at least about 84%, at least about 85%, at least about 86%, at least about 87%, at least about 88%, at least about 89%, at least about 90%, at least about 91%, at least about 92%, at least about 93%, at least about 94%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identical to a wild-type heavy chain or light chain sequence of the P140, iMab (or the MV1 variant), or 515H7 antibody.

In exemplary embodiments, the bispecific antibody ( e.g ., HIV CrossMab antibody) may comprise a sequence that is at least about 60%, at least about 61%, at least about 62%, at least about 63%, at least about 64%, at least about 65%, at least about 66%, at least about 67%, at least about 68%, at least about 69%, at least about 70%, at least about 71%, at least about 72%, at least about 73%, at least about 74%, at least about 75%, at least about 76%, at least about 77%, at least about 78%, at least about 79%, at least about 80%, at least about 81%, at least about 82%, at least about 83%, at least about 84%, at least about 85%, at least about 86%, at least about 87%, at least about 88%, at least about 89%, at least about 90%, at least about 91%, at least about 92%, at least about 93%, at least about 94%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identical to any of the sequences disclosed herein. Homology or identity may be determined in various ways that are within the skill in the art, for instance, using publicly available computer software such as BLAST, BLAST-2, ALIGN or Megalign (DNASTAR) software. BLAST (Basic Local Alignment Search Tool) analysis using the algorithm employed by the programs blastp, blastn, blastx, tblastn and tblastx (Karlin et al ., (1990) PROC. NATL. ACAD. SCI. USA 87, 2264-2268; Altschul, (1993) J. MOL. EVOL. 36, 290- 300; Altschul et al., (1997) NUCLEIC ACIDS RES. 25, 3389-3402, incorporated by reference) are tailored for sequence similarity searching. The approach used by the BLAST program is to first consider similar segments between a query sequence and a database sequence, then to evaluate the statistical significance of all matches that are identified and finally to summarize only those matches which satisfy a preselected threshold of significance. For a discussion of basic issues in similarity searching of sequence databases see Altschul et al., (1994) NATURE GENETICS 6, 119- 129 which is fully incorporated by reference. Those skilled in the art can determine appropriate parameters for measuring alignment, including any algorithms needed to achieve maximal alignment over the full length of the sequences being compared. The search parameters for histogram, descriptions, alignments, expect (i.e., the statistical significance threshold for reporting matches against database sequences), cutoff, matrix and filter are at the default settings. The default scoring matrix used by blastp, blastx, tblastn, and tblastx is the BLOSUM62 matrix (Henikoff et al ., (1992) PROC. NATL. ACAD. SCI. USA 89, 10915-10919, fully incorporated by reference). Four blastn parameters may be adjusted as follows: Q=l0 (gap creation penalty); R=l0 (gap extension penalty); wink=l (generates word hits at every wink.sup.th position along the query); and gapw=l6 (sets the window width within which gapped alignments are

generated). The equivalent Blastp parameter settings may be Q=9; R=2; wink=l; and gapw=32. Searches may also be conducted using the NCBI (National Center for Biotechnology

Information) BLAST Advanced Option parameter ( e.g . : -G, Cost to open gap [Integer]: default = 5 for nucleotides/ 11 for proteins; -E, Cost to extend gap [Integer]: default = 2 for nucleotides/ 1 for proteins; -q, Penalty for nucleotide mismatch [Integer]: default = -3; -r, reward for nucleotide match [Integer]: default = 1; -e, expect value [Real]: default = 10; -W, wordsize [Integer]: default = 11 for nucleotides/ 28 for megablast/ 3 for proteins; -y, Dropoff (X) for blast extensions in bits: default = 20 for blastn/ 7 for others; -X, X dropoff value for gapped alignment (in bits): default = 15 for all programs, not applicable to blastn; and -Z, final X dropoff value for gapped alignment (in bits): 50 for blastn, 25 for others). ClustalW for pairwise protein alignments may also be used (default parameters may include, e.g., Blosum62 matrix and Gap Opening Penalty = 10 and Gap Extension Penalty = 0.1). A Bestfit comparison between sequences, available in the GCG package version 10.0, uses DNA parameters GAP=50 (gap creation penalty) and LEN=3 (gap extension penalty) and the equivalent settings in protein comparisons are GAP=8 and LEN=2.

In various embodiments, the bispecific antibody (e.g, HIV CrossMab antibody) comprises a sequence that includes at least one amino acid alteration with respect to a wild-type heavy or light chain sequence of the PGT145, PG9, PGT128, PGT121, 10-1074, 3BNC117, VRC01, PGT151, 4E10, or 10E8 antibody. In various embodiments, the bispecific antibody (e.g, HIV

CrossMab antibody) comprises a sequence that includes at least one amino acid alteration with respect to a wild-type heavy or light chain sequence of the P140, iMab (or the MV1 variant), 515H7 antibody. In exemplary embodiments, the bispecific antibody (e.g, HIV CrossMab antibody) comprises a sequence that includes at least one amino acid alteration with respect to any of the sequences disclosed herein.

In various embodiments, the bispecific antibody ( e.g ., HIV CrossMab antibody) comprises a sequence that includes at least about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19,

20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45,

46, 47, 40, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71

72, 73, 74, 75, 76, 77, 78, 79, or 80 amino acid alterations with respect to a wild-type heavy or light chain sequence of the PGT145, PG9, PGT128, PGT121, 10-1074, 3BNC117, VRC01, PGT151, 4E10, or 10E8 antibody.

In various embodiments, the bispecific antibody (e.g, HIV CrossMab antibody) comprises a sequence that includes at least about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19,

20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 40, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71,

72, 73, 74, 75, 76, 77, 78, 79, or 80 amino acid alterations with respect to a wild-type heavy or light chain sequence of the P140, iMab (or the MV1 variant), or 515H7 antibody.

In exemplary embodiments, the bispecific antibody (e.g., HIV CrossMab antibody) comprises a sequence that includes at least about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19,

72, 73, 74, 75, 76, 77, 78, 79, or 80 amino acid alterations with respect to any of the sequences disclosed herein.

The amino acid alteration can be an amino acid deletion, insertion, substitution, or modification. In one embodiment, the amino acid alteration is an amino acid deletion. In another embodiment, the amino acid alteration is an amino acid substitution.

In various embodiments, the amino acid alteration may be in the Complementarity Determining Regions (CDRs) of the bispecific antibody (e.g, the CDR1, CDR2 or CDR3 regions). In another embodiment, the amino acid alteration may be in the framework regions (FWs) of the bispecific antibody ( e.g ., the FW1, FW2, FW3, or FW4 regions). In a further embodiment, the amino acid alteration may be in the joining regions (J regions) of the bispecific antibody (e.g., the Jl, J2, J3, J4, J5, J6, or J7 regions). Also provided herein are chimeric antibody derivatives of the bispecific antibodies, i.e., antibody molecules 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. For example, the bispecific antibody may include a heavy and/or light chain in which one or more CDRs or FWs derived from an antibody selected from a PGT145, PG9, PGT128, PGT121, 10-1074, 3BNC117, VRC01, PGT151, 4E10, 10E8, P140, iMab (or the MV1 variant), or 515H7 antibody are replaced with one or more CDRs or FWs derived from a different antibody selected from a PGT145, PG9, PGT128, PGT121, 10-1074, 3BNC117, VRC01, PGT151, 4E10, 10E8, P140, iMab (or the MVl variant), or 515H7 antibody.

In various embodiments, the present invention provides improved bispecific antibodies that demonstrate advantageous properties related to solubility, stability, and therapeutic activity. It is contemplated that such antibodies may be particularly suited for large-scale commercial production. For example, such antibodies may exhibit increased solubility, reduced aggregation, reduced precipitation, and/or enhanced stability or resistance to degradation during

manufacturing.

In an exemplary embodiment, the improved bispecific antibody is a variant of the

l0E8V2.0/iMab antibody (also referred to as lOE8.2/iMab antibody). In such embodiments, the variant may exhibit enhanced solubility, stability, and/or therapeutic activity (e.g., antiviral activity) compared to the parent !0E8V2.0/iMab antibody. In some embodiments, the bispecific antibody (e.g., HIV CrossMab antibody) may comprise a sequence that is at least about 60%, at least about 61%, at least about 62%, at least about 63%, at least about 64%, at least about 65%, at least about 66%, at least about 67%, at least about 68%, at least about 69%, at least about 70%, at least about 71%, at least about 72%, at least about 73%, at least about 74%, at least about 75%, at least about 76%, at least about 77%, at least about 78%, at least about 79%, at least about 80%, at least about 81%, at least about 82%, at least about 83%, at least about 84%, at least about 85%, at least about 86%, at least about 87%, at least about 88%, at least about 89%, at least about 90%, at least about 91%, at least about 92%, at least about 93%, at least about 94%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identical to the heavy chain or light chain sequences of the l0E8V2.0/iMab antibody (i.e., SEQ ID NO: l, SEQ ID NO:2, SEQ ID NO: 33, or SEQ ID NO:34).

In various embodiments, the bispecific antibody ( e.g ., HIV CrossMab antibody) may comprise a sequence that includes at least about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19,

72, 73, 74, 75, 76, 77, 78, 79, or 80 amino acid alterations with respect to the heavy chain or light chain sequences of the l0E8V2.0/iMab antibody (i.e., SEQ ID NO: l, SEQ ID NO:2, SEQ ID NO: 33, or SEQ ID NO:34).

In various embodiments, the bispecific antibody may comprise one or more amino acid alterations in the Complementarity Determining Regions (CDRs) of the l0E8V2.0/iMab antibody (e.g, the CDR1, CDR2 or CDR3 regions). In another embodiment, the bispecific antibody may comprise one or more amino acid alterations in the framework regions (FWs) of the bispecific antibody (e.g, the FW1, FW2, FW3, or FW4 regions). In a further embodiment, the amino acid alterations may be in the joining regions (J regions) of the l0E8V2.0/iMab antibody (e.g, the Jl, J2, J3, J4, J5, J6, or J7 regions). In some embodiments, the bispecific antibody comprises a variant heavy chain derived from 10E8V2.0 (i.e., SEQ ID NO:34). In such embodiments, the bispecific antibody may include one or more mutations at positions selected from L72, 175, F77, L89, Y98, FlOOa, WlOOb, YlOOe, PlOOf, PlOOg, L108, and/or L170 of the heavy chain (the mutation positions on SEQ ID NO: 34 are determined by the Kabat numbering system). In some embodiments, the bispecific antibody may include one or more mutations at positions selected from L72, 175, F77, and/or L108. In some embodiment, the bispecific antibody may include the one or more mutations selected from L72K, I75K, F77T, and L108K. In an embodiment, the bispecific antibody comprises a heavy chain comprising the amino acid sequence of SEQ ID NO: 47.

In some embodiments, the bispecific antibody comprises a variant light chain derived from 10E8V2.0 (i.e., SEQ ID NO:33). In such embodiments, the bispecific antibody may include one or more mutations at positions selected from L15, P40, 145, and Pl 12 of the light chain (the mutation positions on SEQ ID NO: 33 are determined by the Kabat numbering system). In some embodiments, the bispecific antibody may include one or more mutations at positions selected from P40 and 145. In some embodiments, the bispecific antibody may include one or more mutations selected from P40T and I45K. In an embodiment, the bispecific antibody comprises a light chain comprising the amino acid sequence of SEQ ID NO: 46.

In some embodiments, the bispecific antibody comprises a variant light chain derived from MV1 (i.e., SEQ ID NO: 1). In such embodiments, the bispecific antibody may include mutations at positions 52-54 (the mutation position on SEQ ID NO: 1 is determined by the Kabat numbering system). In some embodiments, the bispecific antibody may include amino acid mutations at positions 52-54. In some embodiments, the amino acid at position 52 is mutated to Asn (N), the amino acid at position 53 is mutated to Ser (S), and the amino acid at position 54 is mutated to Thr (T). In some embodiments, the Asn mutation at position 52 is N-linked glycosylated. In an embodiment, the bispecific antibody comprises a light chain comprising the amino acid sequence of SEQ ID NO: 38. In illustrative embodiment, the bispecific antibody comprises a heavy and light chain derived from 10E8 comprising the amino acid sequence of SEQ ID NO: 47 and SEQ ID NO:46, respectively. The bispecific antibody further comprises a heavy and light chain derived from MV1 comprising the amino acid sequence of SEQ ID NO: 1 and SEQ ID NO:2, respectively. Modification of the amino acid sequence of recombinant binding protein is achieved using any known technique in the art e.g ., site-directed mutagenesis or PCR based mutagenesis. Such techniques are described, for example, in Sambrook et al. , Molecular Cloning: A Laboratory Manual , Cold Spring Harbor Press, Plainview, N.Y., 1989 and Ausubel et al, Current Protocols in Molecular Biology, John Wiley & Sons, New York, N.Y., 1989. Methods for producing antibodies, such as those disclosed herein, are known in the art. For example, DNA molecules encoding light chain variable regions and/or heavy chain variable regions can be chemically synthesized using the sequence information provided herein.

Synthetic DNA molecules can be ligated to other appropriate nucleotide sequences, including, e.g, expression control sequences, to produce conventional gene expression constructs encoding the desired antibodies. Production of defined gene constructs is within routine skill in the art. Alternatively, the sequences provided herein can be cloned out of hybridomas by conventional hybridization techniques or polymerase chain reaction (PCR) techniques, using synthetic nucleic acid probes whose sequences are based on sequence information provided herein, or prior art sequence information regarding genes encoding the heavy and light chains. Nucleic acids encoding desired antibodies can be incorporated (ligated) into expression vectors, which can be introduced into host cells through conventional transfection or transformation techniques. Exemplary host cells are E. coli cells, Chinese hamster ovary (CHO) cells, human embryonic kidney 293 (HEK 293) cells, HeLa cells, baby hamster kidney (BHK) cells, monkey kidney cells (COS), human hepatocellular carcinoma cells (e.g, Hep G2), and myeloma cells that do not otherwise produce IgG protein. Transformed host cells can be grown under conditions that permit the host cells to express the genes that encode the immunoglobulin light and/or heavy chain variable regions. Specific expression and purification conditions will vary depending upon the expression system employed.

In various embodiments, the bispecific antibodies of the present invention ( e.g ., HIV CrossMab antibodies) are used in therapy. For example, the bispecific antibody (e.g., HIV CrossMab antibody) can be used to neutralize HIV in a mammal (e.g., a human patient). For example, antibodies of the invention can bind to HIV so as to partially or completely inhibit one or more biological activities of the virus. In an embodiment, the bispecific antibody (e.g, HIV CrossMab antibody) neutralizes a R5-tropic HIV. In another embodiment, the bispecific antibody (e.g, HIV CrossMab antibody) neutralizes a X4-tropic HIV. In a further embodiment, the bispecific antibody (e.g, HIV CrossMab antibody) neutralizes a R5X4 dual -tropic HIV. In some embodiments, use of the antibody to neutralize HIV in a mammal comprises administering to the mammal a therapeutically effective amount of the antibody.

Generally, a therapeutically effective amount of active component is in the range of, for example, about 0.1 mg/kg to about 100 mg/kg, e.g., about 1 mg/kg to about 100 mg/kg, e.g., about 1 mg/kg to about 10 mg/kg of the body weight of the patient. In various embodiments, a therapeutically effective amount of active component is in a range of about 0.01 mg/kg to about 30 mg/kg of the body weight of the patient, for example, about 0.01 mg/kg, about 0.02 mg/kg, about 0.03 mg/kg, about 0.04 mg/kg, about 0.05 mg/kg, about 0.06 mg/kg, about 0.07 mg/kg, about 0.08 mg/kg, about 0.09 mg/kg, about 0.1 mg/kg, about 0.2 mg/kg, about 0.3 mg/kg, about 0.4 mg/kg, about 0.5 mg/kg, about 0.6 mg/kg, about 0.7 mg/kg, about 0.8 mg/kg, about 0.9 mg/kg, about 1 mg/kg, about 1.1 mg/kg, about 1.2 mg/kg, about 1.3 mg/kg, about 1.4 mg/kg, about 1.5 mg/kg, about 1.6 mg/kg, about 1.7 mg/kg, about 1.8 mg/kg, 1.9 mg/kg, about 2 mg/kg, about 3 mg/kg, about 4 mg/kg, about 5 mg/kg, about 6 mg/kg, about 7 mg/kg, about 8 mg/kg, about 9 mg/kg, about 10 mg/kg, about 11 mg/kg, about 12 mg/kg, about 13 mg/kg, about 14 mg/kg, about 15 mg/kg, about 16 mg/kg, about 17 mg/kg, about 18 mg/kg, about 19 mg/kg, about 20 mg/kg, about 21 mg/kg, about 22 mg/kg, about 23 mg/kg, about 24 mg/kg, about 25 mg/kg, about 26 mg/kg, about 27 mg/kg, about 28 mg/kg, about 29 mg/kg, about 30 mg/kg body weight, inclusive of all values and ranges there between. In some embodiments, the therapeutically effective amount of active component is any value between about 1 to 10 mg/kg, between about 10 to 20 mg/kg, between about 20 to 30 mg/kg, between about 30 to 40 mg/kg, between about 40 to 50 mg/kg, between about 50 to 60 mg/kg, between about 60 to 70 mg/kg, between about 70 to 80 mg/kg, between about 80 to 90 mg/kg, or between about 90 to 100 mg/kg.

In some embodiments, the therapeutically effective amount of active component is about 1 mg/kg, about 2 mg/kg, about 3 mg/kg, about 6 mg/kg, about 10 mg/kg, about 20 mg/kg, about 30 mg/kg, or about 60 mg/kg delivered intravenously (IV).

In some embodiments, the therapeutically effective amount of active component is about 2.5 mg/kg, about 5 mg/kg, about 10 mg/kg, or about 20 mg/kg delivered subcutaneously (s.c.) or intramuscularly (i.m).

The amount administered will depend on variables such as the type and extent of disease or indication to be treated, the overall health of the patient, the in vivo potency of the antibody, the pharmaceutical formulation, and the route of administration. The initial dosage can be increased beyond the upper level in order to rapidly achieve the desired blood-level or tissue level.

Alternatively, the initial dosage can be smaller than the optimum, and the dosage may be progressively increased during the course of treatment. Human dosage can be optimized, e.g ., in a conventional Phase I dose escalation study designed to run from, for example, 0.5 mg/kg to 20 mg/kg. Dosing frequency can vary, depending on factors such as route of administration, dosage amount and the disease being treated. Exemplary dosing frequencies are more than once daily, about once per day, about twice a day, about three times a day, about four times a day, about five times a day, about every other day, about every third day, about once a week, about once every two weeks, about once every month, about once every two months, about once every three months, about once every six months, or about once every year. Formulation of antibody -based drugs is within ordinary skill in the art. In various embodiments, the antibodies of the invention may be administered for a prolonged period. For example, the antibodies may be administered for at least about 1 week, at least about 4 weeks, about 8 weeks, or at least about 12 weeks. In some embodiments, the regimen is for at least about 1 month, at least about 6 months, at least about 12 months, at least about 1 year, at least about 2 years, at least about 3 years, at least about 4 years, at least about 5 years, at least about 6 years, at least about 7 years, at least about 8 years, at least about 9 years, at least about 10 years, at least about 15 years, at least about 20 years, at least about 30 years, at least about 40 years, or at least about 50 years.

For therapeutic use, an antibody may be combined with a pharmaceutically acceptable carrier. As used herein,“pharmaceutically acceptable carrier” means buffers, carriers, and excipients suitable for use in contact with the tissues of human beings and animals without excessive toxicity, irritation, allergic response, or other problem or complication, commensurate with a reasonable benefit/risk ratio. The carrier(s) should be“acceptable” in the sense of being compatible with the other ingredients of the formulations and not deleterious to the recipient. Pharmaceutically acceptable carriers include buffers, solvents, dispersion media, coatings, isotonic and absorption delaying agents, and the like, that are compatible with pharmaceutical administration. The use of such media and agents for pharmaceutically active substances is known in the art.

Pharmaceutical compositions containing antibodies, such as those disclosed herein, can be presented in a dosage unit form and can be prepared by any suitable method. A pharmaceutical composition should be formulated to be compatible with its intended route of administration. Examples of routes of administration are intravenous (IV), intradermal, inhalation, transdermal, topical, transmucosal, and rectal administration. In an embodiment, the route of administration for antibodies of the invention is IV infusion. Useful formulations can be prepared by methods well known in the pharmaceutical art. For example, see Remington's Pharmaceutical Sciences ,

18th ed. (Mack Publishing Company, 1990). In some embodiments, the pharmaceutical compositions are formulated as a composition adapted for oral administration. Compositions for oral delivery can be in the form of tablets, lozenges, aqueous or oily suspensions, granules, powders, sprinkles, emulsions, capsules, syrups, or elixirs, for example. Orally administered compositions can comprise one or more agents, for example, sweetening agents such as fructose, aspartame or saccharin; flavoring agents such as peppermint, oil of wintergreen, or cherry; coloring agents; and preserving agents, to provide a

pharmaceutically palatable preparation.

In some embodiments, the pharmaceutical compositions are formulated as a composition adapted for parenteral administration. Dosage forms suitable for parenteral administration ( e.g .

intravenous, subcutaneous, intramuscular, or intraperitoneal injection and infusion) include, for example, solutions, suspensions, dispersions, emulsions, and the like. They may also be manufactured in the form of sterile solid compositions (e.g. lyophilized composition), which can be dissolved or suspended in sterile injectable medium immediately before use. They may contain, for example, suspending or dispersing agents. In some embodiments, the compositions may additionally include pharmaceutically acceptable excipients or carriers. Exemplary excipients include sodium citrate, dicalcium phosphate, etc., and/or a) fillers or extenders such as starches, lactose, sucrose, glucose, mannitol, silicic acid, microcrystalline cellulose, and Bakers Special Sugar, etc., b) binders such as, for example, carboxymethylcellulose, alginates, gelatin, polyvinylpyrrolidone, sucrose, acacia, polyvinyl alcohol, polyvinylpolypyrrolidone, methylcellulose, hydroxypropyl cellulose (HPC), and hydroxymethyl cellulose etc., c) humectants such as glycerol, etc., d) disintegrating agents such as agar-agar, calcium carbonate, potato or tapioca starch, alginic acid, certain silicates, sodium carbonate, cross-linked polymers such as crospovidone (cross-linked polyvinylpyrrolidone), croscarmellose sodium (cross-linked sodium carboxymethylcellulose), sodium starch glycolate, etc., e) solution retarding agents such as paraffin, etc., f) absorption accelerators such as quaternary ammonium compounds, etc., g) wetting agents such as, for example, cetyl alcohol and glycerol monostearate, etc., h) absorbents such as kaolin and bentonite clay, etc., and i) lubricants such as talc, calcium stearate, magnesium stearate, solid polyethylene glycols, sodium lauryl sulfate, glyceryl behenate, etc., and mixtures of such excipients. One of skill in the art will recognize that particular excipients may have two or more functions.

Pharmaceutical formulations preferably are sterile. Sterilization can be accomplished, for example, by filtration through sterile filtration membranes. Where the composition is lyophilized, filter sterilization can be conducted prior to or following lyophilization and reconstitution.

EXAMPLES

Example 1. Construction and Characterization of HIV CrossMab Antibodies

Figures [[13]] 13A-E and Figures 14A-E [[14]] demonstrate that some iMab-based CrossMabs have greater potency and breadth than parental Abs. Except otherwise stated, all iMab-based bispecific antibodies were constructed using the MV1 variant. IC80, the antibody concentration that confers 80% neutralization of viral infectivity, is one method to evaluate antibody potency against HIV. The lower the IC80 number (indicated in the y-axis of the graphs in term of antibody concentration (pg/ml)), the more potent the antibody is at neutralizing a particular HIV strain or isolate. IC50, the antibody concentration that confers 50% neutralization of viral infectivity, is another method to evaluate antibody potency against HIV. The lower the IC50 number (indicated in the y-axis of the graphs in term of antibody concentration (pg/ml)), the more potent the antibody is at neutralizing a particular HIV strain or isolate.

Various sets of antibodies were tested against a large panel of HIV-l pseudoviruses (118 different HIV viral isolates) representative of HIV envelope diversity by geography, clade, tropism, and stage of infection. IC80 and IC50 were used to evaluate the strength of antiviral potency and breadth. Figures 13E and 14E clearly demonstrate that, as compared to the parental antibodies iMab and 10E8, the bispecific CrossMab of the two together (l0E8/iMab) neutralizes almost all HIV viruses (each virus is indicated as a dot) more potently. The other antibody sets (used to make l45/iMab, 1 l7/iMab, l28/iMab and l5l/iMab) sometimes enhance HIV potency compared to their parental components and sometimes do not. As shown in Figures 15A-E , the antibody iMab is also relatively potent in cell-cell neutralizing assays. PGT145, 3BNC117, 10E8, PGT128 and PGT151 are relatively potent at neutralizing cell-free viral infection, but are poor in neutralizing viruses in cell-cell transmission assays. Creating bispecific antibodies including PGT145, 3BNC117, 10E8, PGT128 and PGT151 with iMab makes these chimeric antibodies active at neutralizing viruses in a cell-cell transmission assay. It can be seen that l0E8/iMab is the most potent antibody in these comparative studies. It is also found that l0E8/iMab is most active in preventing cell-cell transmission in vitro.

As illustrated in Figure 16, the improved potency of l0E8/iMab is statistically significant.

Figure 3 shows that improved potency requires covalent linkage of the antibody, i.e., the

CrossMab format (since co-administration of two parental antibodies, iMab and 10E8, provides a lower MPI than the fused and physically linked bispecific l0E8/iMab antibody). Figures 10,

11 A-E, 12A-E, 13 A-E, and 14A-E provide further evidence of the improved potency of iMab- derived CrossMab antibodies over its parental antibodies.

In summary, it is found that, for the iMab-based CrossMabs (fused with PGT145, 3BNC117, PGT151, PGT128 and 10E8), 1 l7/iMab improves breadth but not potency; l45/iMab, l5l/iMab and l28/iMab improve breadth and potency; and l0E8/iMab markedly improves breadth and potency. In terms of epitope location/accessibility and potential models of neutralization, l0E8/iMab appears to exhibit pre- and post-attachment neutralization; l45/iMab, l5l/iMab and 1 l7/iMab appear to exhibit pre-attachment neutralization; and 1 l7/iMab may show signs of steric restriction and potentially reduced potency for some viruses. l0E8/iMab also exhibits potent activity against HIV cell-to-cell transmission.

As also shown in Figures 13A-D and 14A-D, Pro l40-based CrossMab activities are sometimes weaker than their parental antibodies and corresponding iMab-based CrossMabs, as shown by the high concentrations required to reach IC80 and IC50. Anchoring of these four mAbs to the host cell receptor CCR5 via another host cell receptor-binding antibody called Pro 140 does not improve the antiviral potency or breadth (as measured by IC80 against a large panel of HIV isolates) compared to their respective parental antibodies. These panels indicate that Prol40- based CrossMabs for these four antibodies are weaker than their corresponding iMab-based CrossMabs (IC50 and IC80 comparisons of Prol40-based vs. iMab-based CrossMabs).

As shown in Figures 13E and 14E, 10E8/P140, a fifth Pro l40-based CrossMab, is more potent than its parental antibodies and l0E8/iMab CrossMab. These panels illustrate a comparison of the potency (IC80 or IC50) of parental mAb Prol40 (right-most column of data points in Figures 13E and 14E), bispecific CrossMab 10E8/P140 (second from right column of data points in Figures 13E and 14E), and parental mAb 10E8 (center column of data points in Figures 13E and 14E) against a large panel of HIV isolates. These panels also illustrate a comparison of the potency (IC80 or IC50) of parental mAb iMab (left-most column of data points in Figures 13E and 14E), bispecific CrossMab l0E8/iMab (second from left column of data points in Figures 13E and 14E), and parental mAb 10E8 (center column of data points in Figures 13E and 14E) against a large panel of HIV isolates. The second from left and second from right columns of data points in Figures 13E and 14E illustrate a comparison of the potency (IC80 or IC50) of the bispecific CrossMabs l0E8/iMab and 10E8/P140 against a large panel of HIV isolates. Pro 140 is known to not have activity against X4 HIV viruses, as X4 viruses use CXCR4 as a co- receptor for HIV-l entry, and Pro 140 binds to CCR5. 10E8 alone has very weak activity against X4 viruses. However, the bispecific CrossMab l0E8/Pro 140 can neutralize all X4 viruses tested to date better than either of the parent antibodies. Figures 4A-J illustrate the effectiveness of 10E8, Pro 140, and 10E8/P140 bispecific CrossMab antibody in inhibition of various strains of HIV.

As shown in Figures 5A-G, l0E8/Prol40 CrossMab is a more potent inhibitor of various strains of HIV than the co-administration of the two parental antibodies, demonstrating a synergistic, not merely additive, enhancement of potency with this particular bispecific antibody.

As shown in Figures 6A-D, a CrossMab of 10E8 fused to a non-membrane bound antibody (XI 9) does not provide enhanced potency, as can be seen when compared to membrane bound 10E8/P140. Thus, the potency of the 10E8/P140 CrossMab appears to require anchoring of 10E8 to the cell membrane. However, membrane binding alone does not afford the enhanced potency of these CrossMabs. Figures 7A-H show that anchoring 10E8 on HER2 does not provide substantial potency enhancement as compared to anchoring 10E8 on CCR5. Anchoring of 10E8 to a viral receptor specifically (in this case CCR5 via Pro 140 or CD4 via iMab) provides enhanced antiviral activity.

D10E8 is a mutant version of the 10E8 mAh that has a one amino acid deletion in the light chain FR3. Compared to 10E8, D10E8 has a much weaker epitope binding activity, as illustrated in Figures 8A-C. However, once the D10E8 was anchored on a cell receptor (by combining D10E8 and iMab in a CrossMab antibody - iMab specifically binds cell receptor CD4), Figures 8D-E, show that its inhibition activity is improved. These data suggest the contribution of specific cell receptor anchoring, i.e., anchoring on a viral receptor or a viral co-receptor, in enhancing the activity of this HIV antibody. Still, while D10E8/R140 CrossMab has improved antiviral activity over D10E8, it is still not as potent as 10E8/P140 CrossMab. D10E8/R140 CrossMab is comparatively more effective in neutralizing R5 viruses than it is in neutralizing X4 viruses. 4E10 is an anti-gp4l MPER mAh known to be less potent than the anti-gp4l MPER mAh 10E8.

Similar to the results for D10E8, Figures 20 and 21 A-G show that anchoring 4E10 on co-receptor CCR5 (via Pro 140 in a CrossMab antibody) enhanced antiviral activity of 4E10 significantly. Taken together, this suggests that the anchoring of a number of anti-gp4l MPER Abs to either CCR5 or CD4 (via combining the MPER Abs with P140 or iMab in a CrossMab antibody bispecific) can greatly improve the potency and breadth of the respective anti-gp4l MPER Ab.

Multiple parameters contribute to enhanced activity of certain bispecific CrossMabs against HIV, including parental Ab potency, affinity, and pre- and post-attachment neutralization abilities. In particular, the l0E8/Prol40 CrossMab represents an effective combination in terms of overcoming energetic, spatial and temporal constraints, targeting sequential/interdependent steps in the entry process, epitope location/accessibility, binding affinity, pre-and post-attachment neutralization, and binding geometry. As shown in Figure 20, 4El0/Prol40 has a greater binding affinity for MPER than D10E8/RGO140 and !0E8/Prol40. Figures 9A-G show the inhibition potency of 10E8/RIΌ140, D10E8/RGO140 and 4El0/Prol40, and their parental antibodies 10E8, D10E8 and 4E10 against various strains of HIV. Figures 10, 13A-E, 14A-E, 15A-E, 16, and 17A-B provide additional evidence of the greater potency of CrossMab antibodies as compared to their parental antibodies individually and the parental antibodies in combination.

The enhanced antiviral coverage of l0E8/iMab and l0E8/Prol40 CrossMabs is illustrated in Figure 10, which depict the potency and breadth of several antibodies against HIV. The x-axis indicates the concentration of a particular antibody, the y-axis indicates the percent of a large panel of HIV viral isolates neutralized by a particular antibody at a specific concentration, and each line indicates a different antibody evaluated. The left-most lines along the x-axis and those that can closely approach or reach 100% on the y-axis indicate a highly potent and broad antibody against HIV. 10E8/P140 CrossMab and l0E8/iMab CrossMab are among the most effective antibodies with respect to both viral coverage and potency, and are significantly more effective than their parental antibodies. Figures 18A-H and 19A-C show the potency of the CrossMab 10E8/515H7 antibody as compared to its parental antibodies and previously discussed antibodies. The potency of a CrossMab antibody does not appear to correlate directly with the density of cell membrane protein targets, as the density of CCR5 (the target of Prol40) is less than that of CD4 (the target of ibalizumab), yet the potency of l0E8/Prol40-derived CrossMab antibody is greater than that of l0E8/iMab-derived CrossMab antibody.

As shown in Figures 22A-B, the lack of single, sharp peaks in size exclusion chromatography indicates a type of instability indicative of multiple molecular species for 10E8 and l0E8-derived CrossMab antibodies. Table 1 recites various process and formulation modifications used to resolve the 10E8 instability. However, as indicated by the“X” in the SEC or Size Exclusion Chromatography column, the modifications were unsuccessful in providing a single, sharp peak. Table 1 : Process and formulation screen to resolve 10E8 instability

Pairing the 10E8 heavy chain with the light chain of 4E10 resolves the instability issue, as shown in Figure 23, producing a functional, though less potent, antibody. This result indicates that the instability of 10E8 is due to the light chain. Various modifications of the 10E8 light chain, shown in Figures 24B-C, such as removal of a C-terminal serine, engineering a lambda-variable region and kappa-constant region chimera, engineering an additional disulfide bond between the 10E8 heavy and light chains, or genetically grafting kappa light chain regions of non-l0E8 antibodies onto the 10E8 light chain do not fully resolve 10E8 instability. As shown in Figures 25 and 26A-B, the instability is likely due to a combination of the Complementarity Determining

Regions (“CDRs”) and the framework regions (“FWs”) of 10E8. ETsing 10E8-HC/4E10-LC, each 10E8 light chain CDR was grafted into 4E10LC individually or in concert, as shown in Figure 25. Addition of 10E8 LC CDR2 and CDR3 are well tolerated, but addition of 10E8 LC CDR1 disrupts the single peak. When all 10E8 CDRs are grafted onto 4E10, the peak is broad. Grafting 10E8 CDRs or frameworks onto its germline light chain l results in a single peak, as shown in Figure 26A, but effectiveness in MPER binding and HIV neutralization is decreased. Table 2 summarizes the 10E8 light chain variants tested and the efficacy thereof. Table 2: Generated 10E8 LC variants

Variant H6L10 of 10E8 antibody was found to be active, non-autoreactive, and stable by size exclusion chromatography, as shown in Figure 27. H6LlO/Pro 140 and its parental antibodies were found to have comparable pharmacokinetics profiles in mice, as shown in Figure 28.

However, as shown in Figure 29, the H6L10 variant of 10E8 (referred to as l0E8_v I.O) combined with P140 in a bispecific antibody is substantially less potent than 10E8/P140 when tested against a large panel of HIV strains. The H6L10 variant of 10E8 (referred to as 10E8_{n i.}o) combined with iMab in a bispecific antibody retains the same relative amount of potency as compared to l0E8/iMab when tested against a large panel of HIV strains, but l0E8_v i.o/iMab possesses the same instability as l0E8/iMab as determined by size exclusion chromatography and indicated by an X in Table 3. In an embodiment, the H6L10 variant may further include a S74W mutation.

Table 3 below lists exemplary variants, their activities, size exclusion chromatography results, and pharmacokinetics (“PK”) results (see also Figure 46).

Table 3: Exemplary variants that are stable while retaining anti -HIV activity

As indicated above, lOE8vi.o is a somatic variant of 10E8 known as H6L10. As a mAb, H6L10 has a single peak by SEC but reduced activity compared to 10E8. H6L10/Pro 140 CrossMab has single SEC peak and good mouse PK, but reduced anti -HIV activity. H6LlO/iMab CrossMab has double SEC peaks and poor mouse PK, but its activity against HIV is roughly the same as l0E8/iMab. l0E8vi.i includes a single point mutation in H6L10. When paired with Prol40 in a CrossMab bispecific, this construct has single SEC peak and good mouse PK. Its activity against HIV is improved as compared to l0E8Vl .0/Prol40, but still slightly less than that of

l0E8/Prol40. When paired with iMab in a CrossMab bispecific, this construct has double SEC peaks and poor mouse PK, and its activity against HIV is still roughly the same as l0E8/iMab and l0E8Vl.0/iMab. lOE8v2.o is a chimeric antibody variant of 10E8 in which the FW1, CDR1 and part of FW2 are from lOE8vi_.o and in which the remaining part of FW2, CDR2, FW3, CDR3 and FW4 are from 10E8. When paired with Prol40 in a CrossMab bispecific, this construct has double SEC peaks and has reduced activity against HIV as compared to l0E8/Prol40. When paired with iMab in a CrossMab bispecific, this construct has a single SEC peak, good PK, and activity against HIV that is improved over l0E8/iMab. lOE8v3.o is a somatic variant of 10E8 known as Hl 1L1. Hl lLl/Prol40 CrossMab has a single SEC peak and better anti-HIV activity than any other l0E8/Prol40 construct (including the original one identified), but has poor mouse PK due to autoreactivity. Hl lLl/iMab CrossMab has a single SEC peak and anti-HIV activity that is better than the original l0E8/iMab identified and roughly equivalent activity to that observed for !0E8V2.0/iMab, but has poor mouse PK due to autoreactivity. The variant of 10E8 that produced a single SEC peak in the context of a particular CrossMab bispecific was different when paired with Prol40 or iMab. It appears that the stability of the 10E8 arm of these CrossMab bispecific antibodies is context dependent and will vary depending of what antibody it is paired with. Thus, one variant (l0E8vn) was identified that was stable by SEC and with good mouse PK and good anti-HIV activity when paired with Prol40. Another variant (lOE8v2.o) was also identified that was stable by SEC with good mouse PK and with better anti -HIV activity than the originally identified l0E8/iMab.

Table 4 below describes the autoreactivity of tested variants, where“ANA” refers to anti-nuclear activity and“ACA” refers to anti-cardiolipin activity.

Table 4: Autoreactivity assessment in vitro

Figure 30 depicts the pharmacokinetics of 10E8 and CrossMab antibodies derived from several 10E8 variants and iMab or P140 in a mouse model. As shown in Figures [[31]] 31 A-D and 32A- B [[32]], 10E8n_ΐ.i/R140 and lOE8_V2.o/iMab improve anti-HIV activity and stability, and have good stability when stored in PBS at 4°C. Figure 33 depicts a native mass spectroscopy analysis of lOE8v2.o/iMab (N297A). Figures 34A-C compare the activity of 10E8_ni.i/R140 and lOE8v2.o/iMab on a HIV Clade C panel, and compares their IC50 and IC80 efficacy. Figures 35 and 36 compare the potency of 10E8_ni.i/R140, lOE8_V2.o/iMab, and various monoclonal antibodies against HIV.

Example 2. Development of HIV CrossMab Antibodies with Improved Solubility, Stability, and/or Potency

Experiments were conducted to develop l0E8/iMab CrossMab antibodies with improved solubility, stability, and activity.

Initially, a number of hydrophobic residues were identified on the surface of the lOE8.2/iMab antibody (also referred to as the lOE8_V2.o/iMab antibody) which may negatively affect solubility and stability of the bispecific antibody. The hydrophobic residues are presented in Table 5 below (with reference to the Kabat numbering system):

Table 5.

The hydrophobic residues were mutated either alone or in combination to yield lOE8.2/iMab variants that were assessed for their functional activity against HIV and in vivo pharmacokinetic profiles (see Figures 37A-B). The amino acid sequences of the various lOE8.2/iMab variants are provided elsewhere herein.

Specifically, in vitro neutralization assays were performed to test the activity of the lOE8.2/iMab variants against HIV. Pseudoviruses were prepared as previously described in Sun et al. 2014. JAIDS. 66, 473-483. Virus neutralization was assessed with a single cycle assay using TZM-bl cells and HIV-l pseudoviruses as described previously (Seaman et al. 2010. J. Virol. 84, 1439- 1452). As shown in Figure 37A, some of the lOE8.2/iMab variants (e.g., lOE8.2. l/iMab, lOE8.2.2/iMab, and lOE8.2.3/iMab antibodies) retained functional activity in the in vitro HIV-l neutralization assay as compared to the parental lOE8.2/iMab antibody. For in vivo pharmacokinetics analysis, BALB/c mice were divided into groups of three, and mice in each group were administered intraperitoneally with 100 pg of the indicated antibody. Blood was drawn from all animals at Days 1, 2, 4, 7 and 10 post antibody administration, and serum was isolated and analyzed for levels of antibody in individual mice. CoStar 96-Well EIA/RIA plates were coated with 100 ng per well of goat anti-human IgG Fc-g fragment overnight at 4°C. Plates were washed three times with PBS + Tween and blocked with PBS containing 5% milk and 0.5% BSA for 2 hours at room temperature. Mouse serum from the treated animals, and purified antibody in PBS for the standard curves, were added to the wells in 1 :2 serial dilutions in PBS containing 2% milk and 0.2% BSA and incubated for 2 hours. After washing, peroxidase-conjugated goat anti-human IgG was incubated for 1 hour at room temperature. Samples were detected by TMB Liquid Substrate System and spectrophotometric readings were performed at 450 nm. As shown in Figure 37B, some of the lOE8.2/iMab variants (e.g., lOE8.2. l/iMab, lOE8.2.2/iMab, and lOE8.2.3/iMab antibodies) exhibited similar

pharmacokinetic profiles as the parental lOE8.2/iMab antibody.

Additionally, the precipitation profiles of the variants were evaluated under thermal stress- inducing conditions. Specifically, lOE8.2/iMab variants were expressed in 293 cells, purified using a Protein A column, exchanged into a solution of PBS (pH 7.4), and concentrated to >30 mg/mL using a membrane with a nominal molecular weight limit of 50 kDa. Samples were then incubated at 50°C and assessed visually for precipitation at the indicated time points. Results from the thermal stress analysis are shown in Figure 37C. These results indicate that the lOE8.2.3/iMab variant retained the best combination of favorable antiviral activity by in vitro neutralization, favorable in vivo pharmacokinetics, and increased solubility (decreased precipitation) under thermal stress inducing conditions.

Based on the favorable properties of lOE8.2.3/iMab in the precipitation assay, additional hydrophilic variants and combinations were created off of this bispecific antibody backbone variant. Each of these new variants was evaluated for its aggregation potential by size exclusion chromatography (SEC) after incubation in thermal stress-inducing conditions (see Figures 38A- B). In particular, SEC was used to assess the physicochemical homogeneity of the bispecific antibody variants and to resolve monomers from non-monomeric species. Results indicated that the variants lOE8.4/iMab and lOE8.2. lO/iMab exhibited the least aggregation, as indicated by a decreased peak size between 7 mL and 11 mL in Figure 38B. The lOE8.4/iMab variant was advanced into additional solubility and stability studies. This variant comprises a combination of 6 hydrophobic to hydrophilic residue mutations as compared to the parental lOE8.2/iMab antibody. Figures 45A-B provide a sequence alignment of the parental lOE8.2/iMab antibody and the lOE8.4/iMab variant.

Based on the favorable functional and pharmacokinetic characteristics and the reduction in precipitation and aggregation characteristics of the lOE8.4/iMab antibody, additional studies were performed to evaluate the solubility, turbidity, thermostability and forced degradation characteristics of the lOE8.4/iMab antibody in comparison to the lOE8.2/iMab antibody.

For example, the solubility of the lOE8.4/iMab antibody at 4°C was determined. In one set of experiments, the lOE8.2/iMab and lOE8.4/iMab antibodies were each buffer exchanged into target buffers and were concentrated via ultracentrifugation at 3000-5000g, 4°C. Protein concentrations at different time points were determined by absorbance at 280nm using a

NanoDrop 2000 spectrophotometer. All measurements were repeated twice with 2.5 pL sample each time and an average was taken, and then protein concentration was plotted versus time. The maximum protein concentration achieved was determined as the solubility of the protein. As shown in Figures 39A-B, at concentrations above 50mg/mL, the lOE8.4/iMab antibody showed consistently higher protein concentrations and solubility as compared to the lOE8.2/iMab antibody in buffers 1 (acetate buffer, pH 4.5) and 2 (histidine buffer, pH 5.5). The turbidity characteristics of the lOE8.4/iMab antibody were also analyzed. In the analysis, the lOE8.2/iMab and lOE8.4/iMab antibodies were each buffer exchanged into target buffers and were concentrated via ultracentrifugation at 3000-5000g, 4°C. Absorbance at 280 nm and 350 nm were measured over time using a NanoDrop 2000 spectrophotometer. All measurements were repeated twice with 2.5 pL sample each time and an average was taken, and protein concentration (A280) was plotted versus turbidity (A350) for similar timepoints during the ultracentrifugation process. As shown in Figure 40, the turbidity of both lOE8.2/iMab and lOE8.4/iMab antibodies increased with protein concentration over time. In particular, the lOE8.2/iMab antibody showed higher turbidity than lOE8.4/iMab at the same protein

concentrations over 100 mg/mL in both buffer conditions tested. Additionally, the thermostability profile of the lOE8.4/iMab antibody was compared against the parental lOE8.2/iMab antibody using differential scanning calorimetry (DSC). DSC is a thermoanalytical technique in which the difference in the amount of heat required to increase the temperature of a sample and reference is measured as a function of temperature. Each peak in the thermogram corresponds to a heat effect associated with a specific process, such as

crystallization or melting, and is an indication of the stability of a molecule as temperature is increased. To determine the thermostability of the lOE8.2/iMab and lOE8.4/iMab antibodies, each bispecific antibody was buffer exchanged into identical buffer compositions using ultra- filtration centrifugal devices under the condition of 4°C and 3000-5000g. The protein concentrations were then adjusted to -10 mg/mL and aseptically filtered with 0.22-pm filter. Samples were then diluted to 1 mg/mL with reference buffers. Reference buffers (400 pL) were added into the odd-numbered wells of a 96-well plate and 400 pL of samples were added into the even-numbered wells of the same plate. The plates were scanned from 20 °C to 90 °C with a rate of 200 °C/hr. Analysis of thermograms was performed with MicroCal VP-Capillary DSC Automated data analysis software. As shown in Figure 41, both lOE8.2/iMab and lOE8.4/iMab antibodies exhibited similar thermostability when evaluated by DSC.

Figure 42 shows the results from a turbidity analysis after forced degradation of the lOE8.2/iMab and lOE8.4/iMab antibodies. The lOE8.2/iMab and lOE8.4/iMab antibodies were each buffer exchanged into identical buffer compositions using ultra-filtration centrifugal devices under the condition of 4°C and 3000-5000g. The protein concentrations were then adjusted to -10 mg/mL and aseptically filtered with 0.22-pm filter. Samples were then incubated at 50 °C to induce forced degradation, and both pre-centrifugation and post-centrifugation samples of lOE8.2/iMab and lOE8.4/iMab were measured for development of turbidity by absorbance at 350 nm at 0 days, 3 days and 6 days after incubation began. Results indicate that the lOE8.2/iMab antibody exhibited overall higher turbidity than lOE8.4/iMab at all time points studied.

Molecule purity after forced degradation of the lOE8.2/iMab and lOE8.4/iMab antibodies was also assessed. The lOE8.2/iMab and lOE8.4/iMab antibodies were each buffer exchanged into two buffer compositions using ultra-filtration centrifugal devices under the condition of 4°C and 3000-5000g. The protein concentrations were then adjusted to -10 mg/mL and aseptically filtered with 0.22-pm filter. Samples were then incubated at 50 °C to induce forced degradation, and the percentage of molecule purity by SDS-Gel Capillary Electrophoresis in non-reducing conditions was determined at 0 days, 3 days and 6 days after incubation began. To conduct SDS-Gel Capillary Electrophoresis, a denaturing solution was prepared by mixing sample buffer, 10% SDS and 100 mM N-Ethylmaleimide at 20: 1 :0.7 volume ratio. Two microliters of samples and 7pL denaturing solution were mixed well, incubated at 70 °C for 10 mins and spun down.

35 pL FhO was added to the sample, then 42 pL of the mixture was transferred into 96-well plate and centrifuged at 4000 rpm for 20 mins to remove air bubbles. After the plate was loaded, samples were sipped, stained, separated and detected in the Microchip which was filled with destaining-gel, fluorescent dye and marker. The data was then analysed with LabChip GX Reviewer to determine the percentage of intact bispecific antibody molecule versus smaller antibody fragments in each sample. As indicated in Table 6 below, the !0E8.4/iMab antibody showed better intact molecule purity than the lOE8.2/iMab antibody in both buffers at all timepoints studied:

Table 6.

An aggregation analysis was also performed. Specifically, the lOE8.2/iMab and lOE8.4/iMab antibodies were each buffer exchanged into two buffer compositions using ultra-filtration centrifugal devices under the condition of 4°C and 3000-5000g. The protein concentrations were then adjusted to -10 mg/mL and aseptically filtered with 0.22-pm filter. Samples were then incubated at 50 °C to induce forced degradation, and the high molecular weight (HMW) fraction in each protein sample was determined by SE-HPLC (size exclusion chromatography) as a measurement of aggregation. Size exclusion chromatography was performed using an Agilent 1260 Infinity system and a TSKGel G3000SWXL column (300x7.8 mm, 5pm). The mobile phase was 50mM PB, 300 mM NaCl, pH 7.0±0.2 and the flow rate was set as 1.0 mL/min.

Samples were centrifuged (-10000 rpm for 2 min at 4 °C), injected and detected at 280 nm to determine the percentage of HMW in the samples. As shown in Table 7 below, although the lOE8.4/iMab antibody had a larger HMW population at TO, it showed a less rapid change in HMW percentage over time during incubation at the forced degradation-inducing conditions as compared to !0E8.2/iMab.

Table 7.

Additionally, as shown in Figure 43, the functional activities of the lOE8.2/iMab and

lOE8.4/iMab antibodies were compared in vitro. In particular, virus neutralization was assessed with a single cycle assay using TZM-bl cells and 118 HIV-l tier-2 HIV-l Env pseudoviruses representing diverse clades and origins as described previously (Seaman et al. 2010. J. Virol. 84, 1439-1452). Results indicate that, in addition to its improvement in solubility, decrease in turbidity and improvement in biophysical properties under thermal stress inducing conditions, the lOE8.4/iMab antibody also exhibited an approximately 2.5-fold enhancement in

neutralization activity against a large panel of HIV-l Env pseudotyped viruses as compared to lOE8.2/iMab.

The functional activities of the lOE8.2/iMab and lOE8.4/iMab antibodies were also compared in vivo. Immunodeficient NSG mice (NOD . Cg-Prkdc ^cul II2rg ^u ' ^l,jll Sz J ) were reconstituted with human hematopoietic stem cells and infected with Tier-2 clade B HIV- l JR-CSK four weeks prior to the initiation of antibody treatment. Mice were then treated weekly with modified variants of lOE8.2/iMab or lOE8.4/iMab that allowed for their evaluation in humanized mice. As shown in Figure 44, a maximum mean viral load reduction of -1.7 log was observed in mice treated with lOE8.2/iMab, and a maximum mean viral load reduction of -2.4 log was observed in mice treated with lOE8.4/iMab.” The terms and expressions employed herein are used as terms and expressions of description and not of limitation, and there is no intention, in the use of such terms and expressions, of excluding any equivalents of the features shown and described or portions thereof. In addition, having described certain embodiments of the invention, it will be apparent to those of ordinary skill in the art that other embodiments incorporating the concepts disclosed herein may be used without departing from the spirit and scope of the invention. Accordingly, the described embodiments are to be considered in all respects as only illustrative and not restrictive.

Claims

1. A bispecific antibody in a CrossMab format capable of neutralizing HIV, wherein the antibody comprises a light chain and heavy chain portion of a first antibody 10E8, or a variant thereof, that binds to a HIV envelope protein, and a light chain and heavy chain portion of a second antibody ibalizumab, or a variant thereof, that binds to a cell membrane receptor protein or a cell membrane co-receptor protein, wherein

the light chain portion of the first antibody 10E8 comprises an amino acid sequence having at least 97% identity with SEQ ID NO: 33, wherein SEQ ID NO: 33 incorporates 1-4 mutations and the heavy chain portion of the first antibody 10E8 comprises an amino acid sequence having at least 97% identity with SEQ ID NO: 34, wherein SEQ ID NO: 34 incorporates 4-12 mutations; and the light chain portion of the second antibody ibalizumab comprises an amino acid sequence having at least 97% identity with SEQ ID NO: 1, and the heavy chain portion of the second antibody ibalizumab comprises an amino acid sequence having at least 97% with SEQ ID NO: 2; and wherein any amino acid alterations relative to SEQ ID NOS: 1, 2, 33, and 34 are within the variable regions.

2. The bispecific antibody of claim 1, wherein the mutations to SEQ ID NO: 33 are amino acid positions selected from L15, P40, 145, and/or Pl 12.

3. The bispecific antibody of claim 1, wherein the mutations to SEQ ID NO: 33 are amino acid positions selected from P40 and 145.

4. The bispecific antibody of claim 1, wherein the mutations to SEQ ID NO: 33 are P40T and I45K.

5. The bispecific antibody of claim 1, wherein the mutations to SEQ ID NO: 34 are amino acid positions selected from L72, 175, F77, L89, Y98, FlOOa, WlOOb, YlOOe, PlOOf, PlOOg,

L108, and/or L170.

6. The bispecific antibody of claim 1, wherein the mutations to SEQ ID NO: 34 are amino acid positions selected from L72, 175, F77, and/or L108.

7. The bispecific antibody of claim 1, wherein the mutations to SEQ ID NO: 34 are L72K, I75K, F77T, and/or L108K.

8. The bispecific antibody of claim 1, wherein the antibody comprises a light chain portion of an ibalizumab antibody comprising the amino acid sequence of SEQ ID NO: 1

9. The bispecific antibody of claim 1, wherein the antibody comprises a heavy chain portion of an ibalizumab antibody comprising the amino acid sequence of SEQ ID NO: 2.

10. A pharmaceutical composition comprising the bispecific antibody of claim 1, and a

pharmaceutically acceptable carrier.

11. The pharmaceutical composition of claim 10, wherein the composition is formulated for oral, intranasal, pulmonary, intradermal, transdermal, subcutaneous, intramuscular,

intraperitoneal, or intravenous delivery.