Anti-WT1 / HLA-a2 antibody and uses thereof

Abstract

Aspects of the application provide anti-WTl antibodies and methods of using the same in treating WT1-expressing cancer.

Description

ANTI-WT1 / HLA-A2 ANTIBODY AND USES THEREOF RELATED APPLICATIONS

[0001] This application claims the benefit under 35 U.S.C. § 119(e) of U.S. Provisional Application No. 63 / 664,147, filed on June 25, 2024; U.S. Provisional Application No. 63 / 664,149, filed June 25, 2024; and U.S. Provisional Application No. 63 / 664,152, filed June 25, 2024, the entire contents of each of which are hereby incorporated by reference in their entirety. REFERENCE TO AN ELECTRONIC SEQUENCE LISTING

[0002] The contents of the electronic sequence listing (A136170020WO00-SEQ- EMB.xml; Size: 91,644 bytes; Date of Creation: June 24, 2025) is herein incorporated by reference in its entirety. BACKGROUND

[0003] Wilms’ Tumor 1 (WT1) is a cancer-associated transcription factor that is overexpressed in many types of cancer (e.g., acute myelocytic and lymphocytic leukemia, chronic myelocytic leukemia, and solid tumors such as lung cancer). Fragments of WT1 can bind to HLA molecules in cancerous tissues to form a complex that is displayed on cancer cell surfaces and presented to immune cells for targeting. Accordingly, there is a need for antibodies that are capable of binding WT1 peptides that are complexed with HLA molecules. SUMMARY

[0004] The present disclosure, at least in part, relates to the development of antibodies that specifically recognize and bind WT1 peptides when they are complexed with HLA molecules (e.g., HLA-A2). For example, in one aspect, the disclosure features an isolated antibody (e.g., anti-WT1 / HLA-A2 antibody) that mimics a T cell receptor (TCR) that specifically binds a WT1 / HLA-A2 complex. In other aspects, the present disclosure provides T-cell engaging bispecific antibodies targeting WT1 / HLA-A2, which comprises a first antigen binding site that specifically binds a WT1 / HLA-A2 complex (e.g., any of the antigen binding site derived from any one of the anti-WT1 / HLA-A2 antibodies described herein), and a second antigen binding site that specifically binds a T cell antigen (e.g., CD3) (referred to as anti-WT1 / HLA- A2xT cell bispecific antibody). In some embodiments, an anti-WT1 / HLA-A2xT cell Docket No. A1361.70020WO00 1410150.1bispecific antibody recruits a T cell (e.g., cytotoxic T cell) to a cancer cell expressing WT1. In some embodiments, an anti-WT1 / HLA-A2xT cell bispecific antibody elicits T cell mediated immune response (e.g., cytotoxic T cell mediated immune response) against a cancer cell expressing WT1. In some embodiments, an anti-WT1 / HLA-A2xT cell bispecific antibody induces T cell mediated killing (e.g., cytotoxic T cell mediated immune response) of a cancer cell expressing WT1. In some embodiments, an anti-WT1 / HLA-A2xT cell bispecific antibody is useful for treating cancer (e.g., cancer expressing WT1). In other embodiments, the present disclosure also provides a chimeric T cell receptor (CAR) that comprises an antigen binding site of an anti-WT1 / HLA-A2. In some embodiments, a chimeric T cell expressing a CAR comprising an antigen binding site of an anti-WT1 / HLA-A2 can be used for treating cancer (e.g., cancer expressing WT1).

[0005] In some embodiments, the present disclosure provides a means for specifically binding a peptide / HLA-A2 complex, wherein the peptide / HLA-A2 complex is a member of a set of complexes of peptides bound by HLA-A2, each complex comprising a different peptide bound by HLA-A2, wherein each peptide comprises the amino acid sequence of RMFPNAPYL (SEQ ID NO: 75). In some embodiments, the present disclosure provides a means for specifically binding a WT1 / HLA-A2 complex, wherein the WT1 / HLA-A2 complex comprises a WT1 peptide comprising the amino acid sequence of RMFPNAPYL (SEQ ID NO: 75) bound by HLA-A2. In some embodiments, the means for specifically binding a peptide / HLA-A2 complex (e.g., peptide comprising the amino acid sequence of RMFPNAPYL (SEQ ID NO: 75) bound by HLA-A2) is an anti-WT1 / HLA-A2 antibody described herein (e.g., an antibody described in Table 1 or equivalents thereof). In some embodiments, the means for specifically binding a WT1 / HLA-A2 complex (e.g., peptide comprising the amino acid sequence of RMFPNAPYL (SEQ ID NO: 75) bound by HLA-A2) is an anti-WT1 / HLA-A2 antibody described herein (e.g., an antibody described in Table 1 or equivalents thereof).

[0006] In some embodiments, the present disclosure provides means for engaging a T cell to a cancer cell expressing WT1. In some embodiments, the means for engaging a T cell to a cancer cell expressing WT1 is an anti-WT1 / HLA-A2xT cell bispecific antibody described herein. In some embodiments, the present disclosure provides means for eliciting cytotoxic T cell immunity against cancer cells expressing WT1. In some embodiments, the means for eliciting cytotoxic T cell immunity against cancer cells expressing WT1 is an anti- WT1 / HLA-A2xT cell bispecific antibody described herein. Docket No. A1361.70020WO00 1410150.1

[0007] In some embodiments, the present disclosure provides an antibody that specifically binds WT1 / HLA-A2 complex, wherein the improvement comprises one or more of the HC CDR (e.g., HC CDR1, HC CDR2, or HC CDR3) amino acid sequences from any one of an anti-WT1 / HLA-A2 antibody selected from Table 1. In some embodiments, the present disclosure provides an antibody that specifically binds WT1 / HLA-A2 complex, wherein the improvement comprises the HC CDR1, HC CDR2, and HC CDR3 as provided for any one of the antibodies elected from Table 1. In some embodiments, the present disclosure provides an antibody that specifically binds WT1 / HLA-A2 complex, wherein the improvement comprises one or more of the LC CDRs (e.g., LC CDR1, LC CDR2, or LC CDR3) amino acid sequences from any one of an anti-WT1 / HLA-A2 antibody selected from Table 1. In some embodiments, the present disclosure provides an antibody that specifically binds WT1 / HLA-A2 complex, wherein the improvement comprises the LC CDR1, LC CDR2, and LC CDR3 s provided for any one of an anti-WT1 / HLA-A2 antibody selected from Table 1. In some embodiments, the present disclosure provides an antibody that specifically binds WT1 / HLA-A2 complex, wherein the improvement comprises HC CDR1, HC CDR2, and HC CDR3, LC CDR1, LC CDR2, and LC CDR3 as provided for any one of an anti-WT1 / HLA- A2 antibody selected from Table 1.

[0008] In some embodiments, an anti-WT1 / HLA-A2xT cell bispecific antibody comprises a second antigen binding site that specifically binds to CD3, wherein the improvement comprises a first antigen binding site that specifically binds to a WT1 / HLA-A2 complex that comprises any one of the anti-WT1 / HLA-A2 binding sites derived from an anti-WT1 / HLA- A2 antibody described herein (e.g., any one of the anti-WT1 / HLA-A2 binders described in Table 1).

[0009] In some aspects, provided herein is an antibody that binds Wilms’ tumor 1 protein / HLA-A2 complex (WT1 / HLA-A2) comprising: a heavy chain complementarity determining region 1 (HC CDR1) comprising the amino acid sequence X1X2X3X4X5X6X7, wherein: X1is S, R, or absent, X2is S, G, or absent, X3is G or D, X4is Y or S, X5is Y or A, X6 is W or M, and / or X7 is G, S, or H; a heavy chain complementarity determining region 2 (HC CDR2) comprising the amino acid sequence X1X2X3X4X5X6X7X8X9YX11X12SX14X15KX17, wherein: X1is Y, G, or absent, X2is S, E, or I, X3is I, F, or S, X4is Y, S, or W, X5is Y, H, F, or N, X6is S or G, X7is G or S, X8is S, T, or N, X9 is Y, N, or G, X11 is N or A, X12 is P or D, X14 is S or L, X15 is L or V, and / or X17 is S or G; and a heavy chain complementarity determining region 3 (HC CDR3) comprising the Docket No. A1361.70020WO00 1410150.1amino acid sequence X1X2X3X4X5WX7X8X9X10X11X12, wherein: X1is D or absent, X2is H, P, or N, X3 is E, I, or F, X4 is P, Q, or F, X5 is Y, L, or E, X7 is Y, F, or W, X8 is F, D, or G, X9 is D, Y, or T, X10 L, F, or absent, X11 is D or absent, and / or X12 is H, Y, or absent; and a light chain complementarity determining region 1 (LC CDR1) comprising the amino acid sequence RASQX5ISX8X9LX11 (SEQ ID NO: 105), wherein X5 is D or G, X8 is N or S, X9 is Y or W, and / or X11is A or T; and a light chain complementarity determining region 2 (LC CDR2) comprising the amino acid sequence AASX4X5X6S (SEQ ID NO: 106), wherein: X4 is S or T, X5 is L or S, and / or X6 is Q or E; and a light chain complementarity determining region 3 (LC CDR3) comprising the amino acid sequence X1X2X3X4X5X6PX8X9, wherein: X1is L or Q, X2is Q or H, X3is H, Y, or A, X4is N or R, X5is S, N, or T, X6is Y, L, or F, X7is P, X8is R, L, or F; and / or X9 is T.

[0010] In some aspects, provided herein is an antibody that binds Wilms’ tumor 1 protein / HLA-A2 complex (WT1 / HLA-A2) comprising a heavy chain complementarity determining region 1 (HC CDR1) comprising the amino acid sequence X1X2GYYWX3 (SEQ ID NO: 59), wherein X1 is S, T, N, Q, R, K, or absent, X2 is S, T, N, Q, G, or absent, X3 is S, T, N, Q, or G; and a heavy chain complementarity determining region 2 (HC CDR2) comprising the amino acid sequence X4X5YX6SGX7TX8YNPSLKS (SEQ ID NO: 60), wherein X4 is S, T, N, Q, E, or D, X5 is I, V, L, A, Y, W, or F, X6 is Y, W, H, or F, X7 is S, T, Q, or N, X8is Y, W, F, S, T, Q, or N; and a heavy chain complementarity determining region 3 (HC CDR3) comprising the amino acid sequence HEPYWYFDL (SEQ ID NO: 3); and a light chain complementarity determining region 1 (LC CDR1) comprising the amino acid sequence RASQDISNYLX9 (SEQ ID NO: 61), wherein X9 is A, I, V, L, S, N, Q, or T; and a light chain complementarity determining region 2 (LC CDR2) comprising the amino acid sequence AASX10LX11S (SEQ ID NO: 62), wherein X10 is S, T, N, or Q, X11 is S, T, N, Q, D, or E; and a light chain complementarity determining region 3 (LC CDR3) comprising the amino acid sequence X12X13X14X15X16X17PX18T, wherein X12is A, I, V, L, S, N, T, or Q, X13is S, N, T, Q or H, X14 is H, F, W or Y, X15 is S, T, Q, N, K, or R, X16 is S, Q, N, or T, X17 is Y, F, W, A, V, I or L, X18 is K, R, A, V, I, or L.

[0011] In some embodiments, for an antibody provided herein, X1is S, R, or absent, X2is S, G, or absent, X3is S or G, X4is S or E, X5is I or F, X6is Y, H, or F, X7is S, T, or N, X8is Y or N, X10 is S or T, X11 is Q or E, X12 is L or Q, X13 is Q or H, X14 is H or Y, X15 is N or R, X16 is S, N, or T, X17 is Y or L, and / or X18 is R or L. Docket No. A1361.70020WO00 1410150.1

[0012] In some aspects, the present disclosure provides an antibody that binds Wilms’ tumor 1 protein / HLA-A2 complex (WT1 / HLA-A2) comprising a heavy chain complementarity determining region 1 (HC CDR1) comprising the amino acid sequence GYYW (SEQ ID NO: 9), a heavy chain complementarity determining region 2 (HC CDR2) comprising the amino acid sequence YNPSLKS (SEQ ID NO: 10), a heavy chain complementarity determining region 3 (HC CDR3) comprising the amino acid sequence HEPYWYFDL (SEQ ID NO: 3); and a light chain complementarity determining region 1 (LC CDR1) comprising the amino acid sequence RASQDISNYL (SEQ ID NO: 16); and a light chain complementarity determining region 2 (LC CDR2) comprising the amino acid sequence AASX10LX11S (SEQ ID NO: 62), wherein X10is S, T, N, or Q, and / or X11is S, T, N, Q, D, or E; and a light chain complementarity determining region 3 (LC CDR3) comprising the amino acid sequence X12X13X14X15X16X17PX18T, wherein X12 is A, I, V, L, S, N, T, or Q, X13 is S, N, T, Q or H, X14 is H, F, W or Y, X15 is S, T, Q, N, K, or R, X16 is S, Q, N, or T, X17is Y, F, W, A, V, I or L, X18is K, R, A, V, I, or L.

[0013] In some aspects, the present disclosure provides an antibody that binds Wilms’ tumor 1 protein / HLA-A2 complex (WT1 / HLA-A2) comprising: a heavy chain complementarity determining region 1 (HC CDR1) comprising the amino acid sequence DYAMH (SEQ ID NO: 85); and a heavy chain complementarity determining region 2 (HC CDR2) comprising the amino acid sequence GISWNSGNX1GYADSVKG (SEQ ID NO: 95), wherein X1is A, L, V or I; and a heavy chain complementarity determining region 3 (HC CDR3) comprising the amino acid sequence DNFFEWWGTFDX2(SEQ ID NO: 96), wherein X2 is F, W, H or Y; and a light chain complementarity determining region 1 (LC CDR1) comprising the amino acid sequence RASQGISNYLA (SEQ ID NO: 88); and a light chain complementarity determining region 2 (LC CDR2) comprising the amino acid sequence AASSX3QS (SEQ ID NO: 97), wherein X3 is A, V, I, L, T, N, Q, or S; and a light chain complementarity determining region 3 (LC CDR3) comprising the amino acid sequence QQYNX4YPFT (SEQ ID NO: 98), wherein X4is T, Q, N or S.

[0014] In some embodiments, X1 is V or I; X2 is H or Y, H3 is L or S; and / or X4 N or S.

[0015] In some embodiments, an antibody comprises (a) a HC CDR1, a HC CDR2, and a HC CDR3 of a heavy chain variable region (VH) comprising the amino acid sequence of SEQ ID NO: 7, and a LC CDR1, a LC CDR2, and a LC CDR3 of a light chain variable region (VL) comprising the amino acid sequence of SEQ ID NO: 8; (b) a HC CDR1, a HC CDR2, and a HC CDR3 of a VH comprising the amino acid sequence of SEQ ID NO: 14; Docket No. A1361.70020WO00 1410150.1and a LC CDR1, LC CDR2, and LC CDR3 of a VL comprising the amino acid sequence of SEQ ID NO: 15; (c) a HC CDR1, a HC CDR2, and a HC CDR3 of a VH comprising the amino acid sequence of SEQ ID NO: 23; and a LC CDR1, LC CDR2, and LC CDR3 of a VL comprising the amino acid sequence of SEQ ID NO: 24; (d) a HC CDR1, a HC CDR2, and a HC CDR3 of a VH comprising the amino acid sequence of SEQ ID NO: 29; and a LC CDR1, LC CDR2, and LC CDR3 of a VL comprising the amino acid sequence of SEQ ID NO: 30; or (e) a HC CDR1, a HC CDR2, and a HC CDR3 of a VH comprising the amino acid sequence of SEQ ID NO: 35; and a LC CDR1, LC CDR2, and LC CDR3 of a VL comprising the amino acid sequence of SEQ ID NO: 36; (f) a HC CDR1, a HC CDR2, and a HC CDR3 of a heavy chain variable region (VH) comprising the amino acid sequence of SEQ ID NO: 83, and a LC CDR1, a LC CDR2, and a LC CDR3 of a light chain variable region (VL) comprising the amino acid sequence of SEQ ID NO: 84; (g) a HC CDR1, a HC CDR2, and a HC CDR3 of a heavy chain variable region (VH) comprising the amino acid sequence of SEQ ID NO: 90, and a LC CDR1, a LC CDR2, and a LC CDR3 of a light chain variable region (VL) comprising the amino acid sequence of SEQ ID NO: 91; and (h) a HC CDR1, a HC CDR2, and a HC CDR3 of a heavy chain variable region (VH) comprising the amino acid sequence of SEQ ID NO: 93, and a LC CDR1, a LC CDR2, and a LC CDR3 of a light chain variable region (VL) comprising the amino acid sequence of SEQ ID NO: 94.

[0016] In some embodiments, an antibody comprises (a) a HC CDR1 comprising the amino acid sequence of SEQ ID NO: 1, a HC CDR2 comprising the amino acid sequence of SEQ ID NO: 2, a HC CDR3 comprising the amino acid sequence of SEQ ID NO: 3, a LC CDR1 comprising the amino acid sequence of SEQ ID NO: 4, a LC CDR2 comprising the amino acid sequence of SEQ ID NO: 5, and a LC CDR3 comprising the amino acid sequence of SEQ ID NO: 6; (b) a HC CDR1 comprising the amino acid sequence of SEQ ID NO: 11, a HC CDR2 comprising the amino acid sequence of SEQ ID NO: 12, a HC CDR3 comprising the amino acid sequence of SEQ ID NO: 3, a LC CDR1 comprising the amino acid sequence of SEQ ID NO: 4, a LC CDR2 comprising the amino acid sequence of SEQ ID NO: 5, and a LC CDR3 comprising the amino acid sequence of SEQ ID NO: 13; (c) a HC CDR1 comprising the amino acid sequence of SEQ ID NO: 18, a HC CDR2 comprising the amino acid sequence of SEQ ID NO: 19, a HC CDR3 comprising the amino acid sequence of SEQ ID NO: 3, a LC CDR1 comprising the amino acid sequence of SEQ ID NO: 20, a LC CDR2 comprising the amino acid sequence of SEQ ID NO: 21, and a LC CDR3 comprising the amino acid sequence of SEQ ID NO: 22; (d) a HC CDR1 comprising the amino acid Docket No. A1361.70020WO00 1410150.1sequence of SEQ ID NO: 27, a HC CDR2 comprising the amino acid sequence of SEQ ID NO: 12, a HC CDR3 comprising the amino acid sequence of SEQ ID NO: 3, a LC CDR1 comprising the amino acid sequence of SEQ ID NO: 4, a LC CDR2 comprising the amino acid sequence of SEQ ID NO: 5, and a LC CDR3 comprising the amino acid sequence of SEQ ID NO: 28; or (e) a HC CDR1 comprising the amino acid sequence of SEQ ID NO: 1, a HC CDR2 comprising the amino acid sequence of SEQ ID NO: 33, a HC CDR3 comprising the amino acid sequence of SEQ ID NO: 3, a LC CDR1 comprising the amino acid sequence of SEQ ID NO: 20, a LC CDR2 comprising the amino acid sequence of SEQ ID NO: 21, and a LC CDR3 comprising the amino acid sequence of SEQ ID NO: 34; (f) a HC CDR1 comprising the amino acid sequence of SEQ ID NO: 78, a HC CDR2 comprising the amino acid sequence of SEQ ID NO: 79, a HC CDR3 comprising the amino acid sequence of SEQ ID NO: 80, a LC CDR1 comprising the amino acid sequence of SEQ ID NO: 81, a LC CDR2 comprising the amino acid sequence of SEQ ID NO: 5, and a LC CDR3 comprising the amino acid sequence of SEQ ID NO: 82; (g) a HC CDR1 comprising the amino acid sequence of SEQ ID NO: 85, a HC CDR2 comprising the amino acid sequence of SEQ ID NO: 86, a HC CDR3 comprising the amino acid sequence of SEQ ID NO: 87, a LC CDR1 comprising the amino acid sequence of SEQ ID NO: 88, a LC CDR2 comprising the amino acid sequence of SEQ ID NO: 5, and a LC CDR3 comprising the amino acid sequence of SEQ ID NO: 89; or (h) a HC CDR1 comprising the amino acid sequence of SEQ ID NO: 85, a HC CDR2 comprising the amino acid sequence of SEQ ID NO: 86, a HC CDR3 comprising the amino acid sequence of SEQ ID NO: 87, a LC CDR1 comprising the amino acid sequence of SEQ ID NO: 88, a LC CDR2 comprising the amino acid sequence of SEQ ID NO: 89, and a LC CDR3 comprising the amino acid sequence of SEQ ID NO: 92.

[0017] In some embodiments, an antibody comprises (a) a VH comprising the amino acid of SEQ ID NO: 7, and / or a VL comprising the amino acid sequence of SEQ ID NO: 8; (b) a VH comprising the amino acid of SEQ ID NO: 14, and / or a VL comprising the amino acid sequence of SEQ ID NO: 15; (c) a VH comprising the amino acid of SEQ ID NO: 23, and / or a VL comprising the amino acid sequence of SEQ ID NO: 24; (d) a VH comprising the amino acid of SEQ ID NO: 29, and / or a VL comprising the amino acid sequence of SEQ ID NO: 30; or (e) a VH comprising the amino acid of SEQ ID NO: 35, and / or a VL comprising the amino acid sequence of SEQ ID NO: 36; (f) a VH comprising the amino acid of SEQ ID NO: 83, and / or a VL comprising the amino acid sequence of SEQ ID NO: 84; (g) a VH comprising the amino acid of SEQ ID NO: 90, and / or a VL comprising the amino acid Docket No. A1361.70020WO00 1410150.1sequence of SEQ ID NO: 91; or (h) a VH comprising the amino acid of SEQ ID NO: 93, and / or a VL comprising the amino acid sequence of SEQ ID NO: 94.

[0018] In some embodiments, an antibody is a full-length IgG, a Fab fragment, a F(ab') fragment, a F(ab’)2 fragment, a scFv, or a Fv. In some embodiments, an antibody comprises a heavy chain constant region of the isotype IgG1, IgG2, IgG3, or IgG4.

[0019] In some aspects, the disclosure provides an antibody that specifically binds an epitope of a WT1 peptide that is complex with a single chain HLA-A2 molecule, wherein the WT1 peptide comprises the amino acid sequence RMFPNAPYL (SEQ ID NO: 75), wherein an antibody does not specifically bind to (i) a MED13L peptide that is complexed with the single chain HLA-A2 molecule, wherein the MED13L peptide comprising the amino acid sequence RMFPTPPSL (SEQ ID NO: 76); and (ii) a PIGQ peptide that is complexed with the single chain HLA-A2 molecule, wherein the PIGQ peptide comprises the amino acid sequence RMFPGEVAL (SEQ ID NO: 77).

[0020] In some embodiments, an antibody is obtained by a process comprising (1) exposing a single-chain HLA-A2 molecule in complex with the WT1 peptide to a library of antibodies under conditions in which antibodies of the library detectably bind to the single- chain HLA-A2 molecule in complex with the WT1 peptide; (2) obtaining the sequences of a heavy chain variable domain of at least one of the detectably binding antibodies of step (1); and (3) producing an antibody having at least a heavy chain complementarity determining region 3 (HC CDR3) of the heavy chain variable domain of step (2), thereby obtaining an antibody that specifically binds the WT1 peptide complexed with an HLA. In some embodiments, an antibody is obtained by a process further comprising (i) exposing an antibody obtained in step (3) to a MED13L peptide that is complexed with the single chain HLA-A2 molecule; (ii) determining that an antibody does not specifically bind to the MED13L peptide that is complexed with the single chain HLA-A2 molecule.

[0021] In some embodiments, the disclosure provides a chimeric antigen receptor (CAR) comprising an antibody provided herein. In some embodiments, the CAR further comprises a hinge region. In some embodiments, the CAR further comprises a transmembrane domain. In some embodiments, the CAR further comprises an intracellular domain. In some embodiments, the CAR further comprises a co-stimulatory domain.

[0022] In some embodiments, the present disclosure provides an isolated nucleic acid encoding the VH and / or VL of an antibody provided herein or a CAR provided herein. In some embodiments, the isolated nucleic acid comprises (a) the nucleic acid sequence of SEQ Docket No. A1361.70020WO00 1410150.1ID NO: 39, and / or the nucleic acid sequence of SEQ ID NO: 40; (b) the nucleic acid sequence of SEQ ID NO: 43, and / or the nucleic acid sequence of SEQ ID NO: 44; (c) the nucleic acid sequence of SEQ ID NO: 47, and / or the nucleic acid sequence of SEQ ID NO: 48; (d) the nucleic acid sequence of SEQ ID NO: 51, and / or the nucleic acid sequence of SEQ ID NO: 52; or (e) the nucleic acid sequence of SEQ ID NO: 55, and / or the nucleic acid sequence of SEQ ID NO: 56; (f) the nucleic acid sequence of SEQ ID NO: 99, and / or the nucleic acid sequence of SEQ ID NO: 100; (g) the nucleic acid sequence of SEQ ID NO: 101, and / or the nucleic acid sequence of SEQ ID NO: 102; and / or (h) the nucleic acid sequence of SEQ ID NO: 103, and / or the nucleic acid sequence of SEQ ID NO: 104.

[0023] In some embodiments, the disclosure provides an expression vector comprising an isolated nucleic acid provided herein.

[0024] In some embodiments, the disclosure provides a host cell comprising an antibody, a CAR, an isolated nucleic acid, or a vector provided herein.

[0025] In some embodiments, the disclosure provides an engineered cell expressing an antibody or a CAR provided herein. In some embodiments, the engineered cell is a T cell, a NK cell, or a NKT cell.

[0026] In some embodiments, the disclosure provides a composition comprising an antibody, a CAR, an isolated nucleic acid, a vector, a host cell, or an engineered cell provided herein. In some embodiments, the composition further comprises a pharmaceutically acceptable carrier.

[0027] In some embodiments, the disclosure provides a bispecific antibody comprising a first antigen binding site comprising an antibody provided herein, and a second antigen binding site. In some embodiments, the second antigen binding site specifically binds to a T cell antigen. In some embodiments, the T cell antigen is a CD3 complex. In some embodiments, the second antigen binding site specifically binds to CD3δ of the CD3 complex. In some embodiments, the second antigen binding site specifically binds to CD3ε of the CD3 complex. In some embodiments, the second antigen binding site the second antigen binding site specifically binds to CDγ of the CD3 complex. In some embodiments, the second antigen binding site binds to a CD3ε / δ heterodimer of the CD3 complex. In some embodiments, the second antigen binding site binds to a CD3ε / γ heterodimer of the CD3 complex.

[0028] In some embodiments, the bispecific antibody comprises a first arm that is configured as a Fab, a Fab’, or a scFv and that comprises the first antigen binding site. In Docket No. A1361.70020WO00 1410150.1some embodiments, the bispecific antibody comprises a second arm that is configured as a Fab, a Fab’, or a scFv and that comprises the second antigen binding site. In some embodiments, the bispecific antibody comprises a first arm that is configured as a Fab and a second arm that is configured as a scFv. In some embodiments, the bispecific antibody comprises a first arm that is configured as a scFv and a second arm that is configured as a Fab. In some embodiments, the ratio between the first antigen binding site and the second antigen binding site is 1:1, 1:2, 1:3, 2:1 or 3:1.

[0029] In some embodiments, the disclosure provides a host cell comprising a bispecific antibody provided herein.

[0030] In some embodiments, the disclosure provides an engineered cell comprising a bispecific antibody provided herein.

[0031] In some embodiments, the disclosure provides a composition comprising a bispecific antibody provided herein. In some embodiments, the composition further comprises a pharmaceutically acceptable carrier.

[0032] In some embodiments, the disclosure provides a method of treating cancer, wherein the method comprises administering to a subject in need thereof an effective amount of an antibody, an engineered cell, a composition, or a bispecific antibody provided herein.

[0033] The foregoing and other aspects, implementations, acts, functionalities, features and embodiments of the present teachings can be more fully understood from the following description in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate certain embodiments, and together with the written description, serve to provide non-limiting examples of certain aspects of the compositions and methods disclosed herein.

[0035] FIG. 1 shows the binding kinetics curves for anti-WT1 / HLA-A2 candidates binding the WT1 peptide RMFPNAPYL (SEQ ID NO: 75) in complex with HLA-A2.

[0036] FIG. 2 show binding strength of anti-WT1 / HLA-A2 candidates compared to Comparator antibodies as measured by mean fluorescence intensity (MFI).

[0037] FIG. 3 shows IL-2 release of CAR-T cells expressing an exemplary anti- WT1 / HLA-A2 candidate as a function of the ratio of CAR-T cells to SKM-1 leukemic cell line cells. Docket No. A1361.70020WO00 1410150.1

[0038] FIG. 4 shows tumor volume in immunodeficient mice injected with BV173 human B cell leukemia cell line cells receiving either mock transfected CAR-T cells or CAR-T cells expressing an exemplary anti-WT1 / HLA-A2 antibody. DETAILED DESCRIPTION

[0039] The present disclosure, at least in part, is based on the development of antibodies that specifically bind Wilms Tumor Protein (WT1)-HLA-A2 complex (WT1 / HLA-A2). In some embodiments, methods and related compositions are provided that are useful for targeting cells (e.g., tumor cells) that express WT1. Aspects of the disclosure provide anti- WT1 / HLA-A2 antibodies with high binding affinity and specificity to WT1 / HLA-A2 complexes.

[0040] WT1 is a transcription factor that, under normal conditions, is expressed only in the testis and placenta. However, WT1 over-expression has been observed in many types of cancer. As a transcription factor, WT1 is normally an intracellular protein, but in cancer cells, WT1 is broken down into peptides and peptide fragments, which are then bound by HLA molecules, forming a WT1 / MHC complex (e.g., a WT1 / MHC-I complex) or a WT1 / HLA complex (e.g., a WT1 / HLA-A2 complex) that is displayed on the cancer cell surface. Such complexes can be recognized by immune cells, including T effector cells. HLA molecules recognized by CD4+ T cells are encoded by the HLA-DP, HLA-DQ, and HLA-DR genes, while HLA molecules recognized by CD8+ T cells are encoded by the HLA-A, HLA-B, and HLA-C genes. Different alleles of genes encoding HLA molecules result in different HLA serotypes, such as HLA-A2 in the case of HLA-A. In some embodiments, an antibody provided herein specifically binds WT1 complexed with HLA-A2 (also referred to as HLA- A2, HLA-A02, HLA-A*02, or HLA-A*2). HLA-A2 can be further serotyped and separated by allele variation (e.g., HLA-A2:01, HLA-A2:01, HLA-A2:02, HLA-A2:03, HLA-A2:04, HLA-A2:05, HLA-A2:06, HLA-A2:07, HLA-A2:11, etc.). In some embodiments, an anti- WT1 / HLA-A2 antibody specifically binds WT1 complexed with HLA-A serotype HLA- A*02:01.

[0041] Also provided are the use of an anti-WT1 / HLA-A2 antibody and their variants in research, diagnostic / detection, and therapeutic applications. In some embodiments, an anti- WT1 / HLA-A2 antibody and / or an immune cell comprising a chimeric antigen receptor (CAR) comprising an anti-WT1 / HLA-A2 antibody is used to treat cancer in a subject. In some embodiments, an anti-WT1 / HLA-A2 antibody is a bispecific antibody and comprises a Docket No. A1361.70020WO00 1410150.1first binding site that specifically binds WT1 / HLA-A2 and a second binding site. In some embodiments, the second binding site specifically binds a T cell antigen. By having a binding site specific for WT1 / HLA-A2 and a binding moiety specific for a T cell antigen, the bispecific antibody can act as a scaffold, bringing a T cell to a WT1 / HLA-A2 expressing cell, e.g., a WT1 / HLA-A2 expressing cancer cell, to induce an immune response against the WT1 / HLA-A2 expressing cancer cell. One significant drawback to current antibodies targeting WT1-expressing cancer cells (e.g., current anti-WT1 / HLA antibodies) is that WT1 target peptides have high homology to regions of other endogenous proteins, e.g., PIGQ and M13L. Off-target binding of endogenous proteins or peptides can result in poor outcomes, including inflammation and / or autoimmunity. Accordingly, in some embodiments, antibodies described herein show high binding affinity and specificity to WT1 / HLA-A2 and do not exhibit binding to off-target peptides or proteins. The generation of the highly specific anti- WT1 / HLA-A2 antibodies provided by the present disclosure thus represents a significant advancement in the field.

[0042] The foregoing and other aspects, implementations, acts, functionalities, features and embodiments of the present teachings can be more fully understood from the following description in conjunction with the accompanying drawings. I. Definitions

[0043] Administering: As used herein, the terms “administering” or “administration” means to provide an antibody or a composition thereof to a subject in a manner that is physiologically and / or pharmacologically useful (e.g., to treat a condition in the subject).

[0044] Affinity Matured Antibody: “Affinity Matured Antibody” is used herein to refer to an antibody with one or more alterations in one or more CDRs, which result in an improvement in the affinity (e.g., KD, kd or ka) of an antibody for a target antigen compared to a parent antibody, which does not possess the alteration(s). Exemplary affinity matured antibodies will have nanomolar or even picomolar affinities for the target antigen. A variety of procedures for producing affinity matured antibodies are known in the art, including the screening of a combinatory antibody library that has been prepared using bio-display. For example, Marks et al., BioTechnology, 10: 779-783 (1992) describes affinity maturation by VH and VL domain shuffling. Random mutagenesis of CDR and / or framework residues is described by Barbas et al., Proc. Nat. Acad. Sci. USA, 91: 3809-3813 (1994); Schier et al., Gene, 169: 147-155 (1995); Yelton et al., J. Immunol., 155: 1994-2004 (1995); Jackson et al., Docket No. A1361.70020WO00 1410150.1J. Immunol., 154(7): 3310-3319 (1995); and Hawkins et al, J. Mol. Biol., 226: 889-896 (1992). Selective mutation at selective mutagenesis positions and at contact or hypermutation positions with an activity-enhancing amino acid residue is described in U.S. Pat. No. 6,914,128 B1.

[0045] Antibody: As used herein, the term “antibody” refers to a polypeptide that includes at least one immunoglobulin variable domain or at least one site, e.g., paratope, that specifically binds to an antigen. In some embodiments, an antibody comprises a paratope. In some embodiments, a paratope comprises one or more complementarity determining regions (CDRs). In some embodiments, an antibody is a full-length antibody. In some embodiments, an antibody is a chimeric antibody. In some embodiments, an antibody is a humanized antibody. However, in some embodiments, an antibody is an antigen-binding fragment, such as, but not limited to, a Fab fragment, a F(ab')2 fragment, a Fv fragment or a scFv fragment. In some embodiments, an antibody is a nanobody derived from a camelid antibody or a nanobody derived from shark antibody. In some embodiments, an antibody is a diabody. In some embodiments, an antibody comprises a framework having a human germline sequence. In another embodiment, an antibody comprises a heavy chain constant domain selected from the group consisting of IgG, IgG1, IgG2, IgG2A, IgG2B, IgG2C, IgG3, IgG4, IgA1, IgA2, IgD, IgM, and IgE constant domains. In some embodiments, an antibody comprises a heavy (H) chain variable region (abbreviated herein as VH), and / or a light (L) chain variable region (abbreviated herein as VL). In some embodiments, an antibody comprises a constant domain, e.g., an Fc region. An immunoglobulin constant domain refers to a heavy or light chain constant domain. Human IgG heavy chain and light chain constant domain amino acid sequences and their functional variations are known. With respect to the heavy chain, in some embodiments, the heavy chain of an antibody described herein can be an alpha (α), delta (∆), epsilon (ε), gamma (γ) or mu (µ) heavy chain. In some embodiments, the heavy chain of an antibody described herein can comprise a human alpha (α), delta (∆), epsilon (ε), gamma (γ) or mu (µ) heavy chain. In a particular embodiment, an antibody described herein comprises a human gamma 1 CH1, CH2, and / or CH3 domain. In some embodiments, the amino acid sequence of the VHdomain comprises the amino acid sequence of a human gamma (γ) heavy chain constant region, such as any known in the art. Non-limiting examples of human constant region sequences have been described in the art, e.g., see U.S. Pat. No. 5,693,780 and Kabat E A et al., (1991) supra. In some embodiments, the VH domain comprises an amino acid sequence that is at least 70%, 75%, 80%, 85%, 90%, 95%, 98%, or Docket No. A1361.70020WO00 1410150.1at least 99% identical to any of the variable chain constant regions provided herein. In some embodiments, an antibody is modified, e.g., modified via glycosylation, phosphorylation, sumoylation, and / or methylation. In some embodiments, an antibody is a glycosylated antibody, which is conjugated to one or more sugar or carbohydrate molecules. In some embodiments, the one or more sugar or carbohydrate molecule are conjugated to an antibody via N-glycosylation, O-glycosylation, C-glycosylation, glypiation (GPI anchor attachment), and / or phosphoglycosylation. In some embodiments, the one or more sugar or carbohydrate molecule are monosaccharides, disaccharides, oligosaccharides, or glycans. In some embodiments, the one or more sugar or carbohydrate molecule is a branched oligosaccharide or a branched glycan. In some embodiments, the one or more sugar or carbohydrate molecule includes a mannose unit, a glucose unit, an N-acetylglucosamine unit, or a phospholipid unit. In some embodiments, an antibody is a construct that comprises a polypeptide comprising one or more antigen binding fragments of the disclosure linked to a linker polypeptide or an immunoglobulin constant domain. Linker polypeptides comprise two or more amino acid residues joined by peptide bonds and are used to link one or more antigen binding portions. Examples of linker polypeptides have been reported (see e.g., Holliger, P., et al. (1993) Proc. Natl. Acad. Sci. USA 90:6444-6448; Poljak, R. J., et al. (1994) Structure 2:1121-1123). Still further, an antibody may be part of a larger immunoadhesion molecule, formed by covalent or noncovalent association of the antibody or antibody portion with one or more other proteins or peptides. Examples of such immunoadhesion molecules include use of the streptavidin core region to make a tetrameric scFv molecule (Kipriyanov, S. M., et al. (1995) Human Antibodies and Hybridomas 6:93-101) and use of a cysteine residue, a marker peptide and a C-terminal polyhistidine tag to make bivalent and biotinylated scFv molecules (Kipriyanov, S. M., et al. (1994) Mol. Immunol. 31:1047-1058).

[0046] Approximately: As used herein, the term “approximately” or “about,” as applied to one or more values of interest, refers to a value that is similar to a stated reference value. In certain embodiments, the term “approximately” or “about” refers to a range of values that fall within 15%, 14%, 13%, 12%, 11%, 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, or less in either direction (greater than or less than) of the stated reference value unless otherwise stated or otherwise evident from the context (except where such number would exceed 100% of a possible value).

[0047] Bispecific Antibody: As used herein, the term “bispecific antibody” refers to a polypeptide or a complex (e.g., two covalently linked polypeptides) that includes two Docket No. A1361.70020WO00 1410150.1different antigen binding, e.g., paratopes, that have different antigen binding specificities. For example, in one embodiment, a bispecific antibody is a polypeptide that includes two different antigen binding sites in which each antigen binding site binds to a different epitope of the same antigen. In other embodiments, a bispecific antibody is a polypeptide that includes two different antigen binding sites in which each site binds to a different antigen. In some embodiments, a bispecific antibody comprises two different sets of immunoglobulin variable domains, each of which set binds to a different epitope or group of epitopes. In some embodiments, at least one antigen to which an antigen binding site of a bispecific antibody specifically binds is a complex (e.g., a peptide complexed with a single chain HLA-A2 molecule).

[0048] Typically, each of the two antigen binding sites is present within an “arm” of a bispecific antibody. In some embodiments, an arm of a bispecific antibody is configured as a monospecific antibody, e.g., a full-length IgG or a fragment thereof. In some embodiments, a bispecific antibody comprises two arms, one or each of which is configured as an Fv region that confers specificity to distinct antigen residues. In some embodiments, a bispecific antibody comprises two arms of the same configuration, e.g., a Fab, a Fab’, a scFv, or any other suitable format. In some embodiments, a bispecific antibody comprises two arms of two different configurations, e.g., a Fab on one arm and a scFv on the other arm. In some embodiments, a bispecific antibody does not comprise an Fc region. In some embodiments, the two arms of a bispecific antibody are linked directly. In some embodiments, the two arms of a bispecific antibody are linked by a linker. In some embodiments, a bispecific antibody comprises an Fc region, e.g., a dimeric Fc or a monomeric Fc. In some embodiments, a bispecific antibody comprises a monomeric Fc. In some embodiments, a bispecific antibody comprises one arm linked to one end (e.g., the N terminal) of a monomeric Fc and a second arm linked to the other end (e.g., the C terminal) of the monomeric Fc (see, e.g., Shan et al., “In vivo pharmacokinetic enhancement of monomeric Fc and monovalent bispecific designs through structural guidance”, Communications Biology, Vol. 4, Article No. 1048 (2021)). In some embodiments, a bispecific antibody comprises a dimeric Fc region. In some embodiments, a bispecific antibody comprises two arms that are oriented symmetrically around an Fc region (e.g., each Fc monomer of a dimeric Fc region is linked to one arm). In some embodiments, a bispecific antibody comprises two distinct heavy chains and two distinct light chains, with each heavy chain / light chain pair having different antigen binding specificity. In some embodiments, a bispecific antibody comprises two arms that are oriented Docket No. A1361.70020WO00 1410150.1asymmetrically around an Fc (e.g., the two arms of the bispecific antibody are linked to one of the monomers of a dimeric Fc region). In some embodiments, because bispecific antibodies are capable of binding two different targets, they can be used as scaffolds to recruit or redirect cells to antigenic targets, e.g., to recruit immune cells to cancer cells. In some embodiments, a bispecific antibody contains a first antigen binding site that specifically binds a peptide:MHC complex (e.g., WT1 / HLA-A2 complex)and a second antigen binding site. In some embodiments, a bispecific antibody comprises a second antigen binding site specifically binds to a T cell antigen. In some embodiments, the T cell antigen is a CD3 complex or a portion thereof, e.g., CD3δ, CD3ε, CD3γ, a CD3ε / δ heterodimer, or a CD3ε / γ heterodimer. In some embodiments, a bispecific antibody comprises a first antigen binding site structured as a T cell receptor-mimic (TCRm) antibody that specifically binds to a peptide:MHC complex (e.g., WT1 / HLA-2 complex), and a second binding site that specifically binds to a T cell antigen (e.g., CD3).

[0049] CDR: As used herein, the term "CDR" refers to the complementarity determining region within antibody variable sequences. A typical antibody molecule comprises a heavy chain variable region (VH) and a light chain variable region (VL), which are usually involved in antigen binding. The VH and VL regions can be further subdivided into regions of hypervariability, also known as “complementarity determining regions” (“CDR”), interspersed with regions that are more conserved, which are known as “framework regions” (“FR”). Each VH and VL is typically composed of three CDRs and four FRs, arranged from amino-terminus to carboxy-terminus in the following order: FR1, CDR1, FR2, CDR2, FR3, CDR3, FR4. The extent of the framework region and CDRs can be precisely identified using methodology known in the art, for example, by the Kabat definition, the IMGT definition, the Chothia definition, the AbM definition, and / or the contact definition, all of which are well known in the art. See, e.g., Kabat, E.A., et al. (1991) Sequences of Proteins of Immunological Interest, Fifth Edition, U.S. Department of Health and Human Services, NIH Publication No. 91-3242; IMGT®, the international ImMunoGeneTics information system® http: / / www.imgt.org, Lefranc, M.-P. et al., Nucleic Acids Res., 27:209-212 (1999); Ruiz, M. et al., Nucleic Acids Res., 28:219-221 (2000); Lefranc, M.-P., Nucleic Acids Res., 29:207- 209 (2001); Lefranc, M.-P., Nucleic Acids Res., 31:307-310 (2003); Lefranc, M.-P. et al., In Silico Biol., 5, 0006 (2004) [[Epub]], 5:45-60 (2005); Lefranc, M.-P. et al., Nucleic Acids Res., 33:D593-597 (2005); Lefranc, M.-P. et al., Nucleic Acids Res., 37:D1006-1012 (2009); Lefranc, M.-P. et al., Nucleic Acids Res., 43:D413-422 (2015); Chothia et al., (1989) Nature Docket No. A1361.70020WO00 1410150.1342:877; Chothia, C. et al. (1987) J. Mol. Biol. 196:901-917, Al-lazikani et al (1997) J. Molec. Biol. 273:927-948; and Almagro, J. Mol. Recognit. 17:132-143 (2004). See also hgmp.mrc.ac.uk and bioinf.org.uk / abs. As used herein, a CDR may refer to the CDR defined by any method known in the art. Two antibodies having the same CDR means that the two antibodies have the same amino acid sequence of that CDR as determined by the same method, for example, the IMGT definition.

[0050] In certain embodiments, there are three CDRs in each of the variable regions of a heavy chain and a light chain, which are designated CDR1, CDR2 and CDR3, for each of the variable regions. The term "CDR set" as used herein refers to a group of three CDRs that occur in a single variable region capable of binding the antigen. The exact boundaries of these CDRs have been defined differently according to different systems. The system described by Kabat (Kabat et al., Sequences of Proteins of Immunological Interest (National Institutes of Health, Bethesda, Md. (1987) and (1991)) not only provides an unambiguous residue numbering system applicable to any variable region of an antibody, but also provides precise residue boundaries defining the three CDRs. These CDRs may be referred to as Kabat CDRs. Sub-portions of CDRs may be designated as LC CDR1, LC CDR2 and LC CDR3 or HC CDR1, HC CDR2 and HC CDR3 where the "LC" and the "HC" designate the light chain and the heavy chains regions, respectively. These regions may be referred to as Chothia CDRs, which have boundaries that overlap with Kabat CDRs. Other boundaries defining CDRs overlapping with the Kabat CDRs have been described by Padlan (FASEB J. 9:133- 139 (1995)) and MacCallum (J Mol Biol 262(5):732-45 (1996)). Still other CDR boundary definitions may not strictly follow one of the above systems, but will nonetheless overlap with the Kabat CDRs, although they may be shortened or lengthened in light of prediction or experimental findings that particular residues or groups of residues or even entire CDRs do not significantly impact antigen binding. The methods used herein may utilize CDRs defined according to any of these systems, although preferred embodiments use Kabat or Chothia defined CDRs.

[0051] In certain embodiments, the CDRs of an antibody may have different amino acid sequences when different definition systems are used (e.g., the IMGT definition, the Kabat definition, or the Chothia definition). A definition system annotates each amino acid in a given antibody sequence (e.g., VH or VL sequence) with a number, and numbers corresponding to the heavy chain and light chain CDRs are provided in Table 2. The CDRs listed in Table 1 are defined in accordance with the Kabat definition. One skilled in the art is Docket No. A1361.70020WO00 1410150.1able to derive the CDR sequences using the different numbering systems for the anti- WT1 / HLA-A2 antibodies provided in Table 1. Table 2. CDR Definitions IMGT1Kabat2Chothia31IMGT®, the international ic Acids Res.,27:209-212 (1999) (incorporated herein by reference)2Kabat et al. (1991) Sequences of Proteins of Immunological Interest, Fifth Edition, U.S. Department of Health and Human Services, NIH Publication No. 91-3242 (incorporated herein by reference)3Chothia et al., J. Mol. Biol. 196:901-917 (1987)) (incorporated herein by reference)

[0052] CDR-grafted antibody: The term "CDR-grafted antibody" refers to antibodies which comprise heavy and light chain variable region sequences from one species but in which the sequences of one or more of the CDR regions of VH and / or VL are replaced with CDR sequences of another species, such as antibodies having murine heavy and light chain variable regions in which one or more of the murine CDRs (e.g., CDR3) has been replaced with human CDR sequences.

[0053] Chemotherapeutic agent: As used herein, a "chemotherapeutic agent" refers to a chemical compound useful in the treatment of proliferative disorders, such as cancers (e.g., cancers expressing CD22). These agents can be, e.g., alkylating agents, such as thiotepa and cyclophosphamide (CYTOXAN®); alkylsulfonates such as busulfan, improsulfan and piposulfane; aziridines such as benzodopa, carbocuone, meturedopa and uredopa; ethylene imines and methylamelamines, including altretamine, triethylene methamine, triethylene phosphoramide, triethylene-thiophosphoramide and trimethylolomelamine; acetogenins (especially bulatacin and bulatacinone); delta-9-tetrahydrocannabinol (dronabinol, MARINOL); beta-lapacona; lapacol; Colchicines; betulinic acid; a camptothecin (which includes the synthetic analog topotecan (HYCAMTIN®), CPT-11 (irinotecan, CAMPTOSAR), acetylcamptothecin, scopolectin and 9-aminocamptothecin); Bryostatin; Callistatin; CC-1065 (including its synthetic analogs of adozelesin, carzelesin and bizelesin); podophyllotoxin; podophyllinic acid; teniposide; cryptophycins (particularly cryptophycin 1 and cryptophycin 8); dolastatin; duocarmycin (which include the synthetic analogs, KW-2189 and CB1-TM1); eleutherobin; pancratistatin; a sarcodictiina, -pongistatin; nitrogen mustards Docket No. A1361.70020WO00 1410150.1such as chlorambucil, chlornaphazine, colofosfamide, estramustine, ifosfamide, mechlorethamine, mechlorethamine oxide hydrochloride, melphalan, novembichin, phenesterin, prednimustine, trofosfamidea, uracil mustard; nitrosureas such as carmustine, chlorozotocin, fotemustine, lomustine, nimustine and ranimnustine; antibiotics, such as enediin antibiotics (e.g., calicheamicin, especially gammall calicheamicin and omegall calicheamicin (see, for example, Agnew, Chem Intl. Ed. Engl., 33: 183-186 (1994)); dynemycin, including dynemycin A; a esperamycin; as well as neocarzinostatin chromophore and chromophores of related chromoprotein antibiotics), aclacinomisins, actinomycin, autramycin, azaserin, bleomycin, cactinomycin, carabicin, carminomycin, carzinophilin, chromomycins, dactinomycin, daunorubicin, detorrubicin, 6-diazo-5-oxo- L-norleucine, doxorubicin (including morpholino-doxorubicin, cyanomorpholino-doxorubicin, 2-pyrrolino- doxorubicin and deoxydoxorubicin), epirubicin, esorubicin, idarubicin, marcellomycin, mitomycins such as mitomycin C, mycophenolic acid, nogalamycin, olivomycins, peplomycin, porfiromycin, puromycin , chelamicin, rodrububicin, streptonigrin, streptozocin, tubercidin, ubenimex, zinostatin, zorubicin; anti-metabolites such as methotrexate and 5- fluorouracil (5-FU); folic acid analogues such as denopterin, methotrexate, pteropterin, trimetrexate; purine analogues such as fludarabine, 6-mercaptopurine, tiamiprin, thioguanine; analogues of pyrimidine such as ancitabine, azacitidine, 6-azauridine, carmofur, cytarabine, dideoxyuridine, doxifluridine, enocythabin, floxuridine; androgens such as calusterone, dromostanolone propionate, epithiostanol, mepitiostane, testolactone; antisuprenal drugs such as aminoglutethimide, mitotane, trilostane; folic acid enhancer such as frolinic acid; aceglatone; aldophosphamide glycoside; aminolevulinic acid; eniluracil; amsacrine; bestrabuchil; bisantrene; edatraxate; defofamin; demecolcine; diazicuone; elfornitin; eliptinium acetate; an epothilone; etoglucid; gallium nitrate; hydroxyurea; lentinan; lonidainin; maytansinoids such as maytansine and ansamitocins; mitoguazone; mitoxantrone; mopidanmol; nitraerine; pentostatin; fenamet; pirarubicin; losoxantrone; 2-ethylhydrazide; procarbazine; PSK® polysaccharide complex (JHS Natural Products, Eugene, OR); razoxane; rhizoxin; sizofirano; spirogermanium; tenuazonic acid; triazicuone; 2,2 ', 2"- trichlorotriethylamine, trichothecenes (especially T-2 toxin, verracurin A, roridin A and anguidine), urethane, vindesine (ELDISINE, FILDESIN), dacarbazine, manomustine, mitobronitol, mitolactol, pipobroman, gacitosin, arabinoside ("Ara-C"), thiotepa, taxoids, for example, paclitaxel (TAXOL, Bristol-Myers Squibb Oncology, Princeton, NJ), Cremophor- free ABRAXANE ™, nanoparticle formulation modified with paclitaxel albumin (American Docket No. A1361.70020WO00 1410150.1Pharmaceutical Partners, Schaumberg, Illinois), and docetaxel (TAXOTERE®; Rhone- Poulenc Rorer, Antony, France); chloranbuchil; gemcitabine (GEMZAR); 6-thioguanine; mercaptopurine; methotrexate; platinum analogues such as cisplatin and carboplatin; vinblastine (VELBAN®); platinum; etoposide (VP-16); ifosfamide; mitoxantrone; vincristine (ONCOVIN®); oxaliplatin; leucovovina; vinorrelbine (NAVELBINE®); novantrone; edatrexate; Daunomycin; aminopterin; ibandronate; Topoisomerase inhibitor RFS 2000; difluoromethylornithine (DMFO); retinoids such as retinoic acid; capecitabine (XELODA®); pharmaceutically acceptable salts, acids or derivatives of any of the foregoing; as well as combinations of two or more of the foregoing such as CHOP, an abbreviation for a combination therapy of cyclophosphamide, doxorubicin, vincristine and prednisolone; CVP, an abbreviation for a combination therapy of cyclophosphamide, vincristine and prednisolone; and FOLFOX, an abbreviation for an oxaliplatin treatment regimen (ELOXATIN ™) combined with 5-FU and leucovorin.

[0054] Chimeric antibody: The term "chimeric antibody" refers to antibodies which comprise heavy and light chain variable region sequences from one species and constant region sequences from another species, such as antibodies having murine heavy and light chain variable regions linked to human constant regions.

[0055] Compete: The term “compete”, as used herein with regard to an antibody, means that a first antibody binds to an epitope of a protein (e.g., CD22) in a manner sufficiently similar to the binding of a second antibody, such that the result of binding of the first antibody with its epitope is detectably decreased in the presence of the second antibody compared to the binding of the first antibody in the absence of the second antibody. The alternative, where the binding of the second antibody to its epitope is also detectably decreased in the presence of the first antibody, can, but need not be the case. That is, a first antibody can inhibit the binding of a second antibody to its epitope without that second antibody inhibiting the binding of the first antibody to its respective epitope. However, where each antibody detectably inhibits the binding of the other antibody with its epitope or ligand, whether to the same, greater, or lesser extent, the antibodies are said to “Cross-compete” with each other for binding of their respective epitope(s). In some embodiments, antibodies that compete or cross-compete bind to the same or overlapping epitopes. Regardless of the mechanism by which such competition or cross-competition occurs (e.g., steric hindrance, conformational change, or binding to a common epitope, or portion thereof), the skilled Docket No. A1361.70020WO00 1410150.1artisan would appreciate that such competing and / or cross-competing antibodies are encompassed and can be useful for the methods and / or compositions provided herein.

[0056] Complementary: As used herein, the term “complementary” refers to the capacity for precise pairing between two nucleotides or two sets of nucleotides. In particular, complementary is a term that characterizes an extent of hydrogen bond pairing that brings about binding between two nucleotides or two sets of nucleotides. For example, if a base at one position of an oligonucleotide is capable of hydrogen bonding with a base at the corresponding position of a target nucleic acid (e.g., an mRNA), then the bases are considered to be complementary to each other at that position. Base pairings may include both canonical Watson-Crick base pairing and non-Watson-Crick base pairing (e.g., Wobble base pairing and Hoogsteen base pairing). For example, in some embodiments, for complementary base pairings, adenosine-type bases (A) are complementary to thymidine- type bases (T) or uracil-type bases (U), that cytosine-type bases (C) are complementary to guanosine-type bases (G), and that universal bases such as 3-nitropyrrole or 5-nitroindole can hybridize to and are considered complementary to any A, C, U, or T. Inosine (I) has also been considered in the art to be a universal base and is considered complementary to any A, C, U or T.

[0057] Conjugated: As used herein, “conjugated” means two entities are associated, preferably with sufficient affinity that a therapeutic / diagnostic benefit of the association between the two entities is realized. The association between the two entities can be either direct or via a linker, such as a polymer linker. Conjugated can include covalent or noncovalent bonding as well as other forms of association, such as entrapment, e.g., of one entity on or within the other, or of either or both entities on or within a third entity, such as a micelle.

[0058] Conservative amino acid substitution: As used herein, a “conservative amino acid substitution” refers to an amino acid substitution that does not alter the relative charge or size characteristics of the protein in which the amino acid substitution is made. Variants can be prepared according to methods for altering polypeptide sequence known to one of ordinary skill in the art such as are found in references which compile such methods, e.g. Molecular Cloning: A Laboratory Manual, J. Sambrook, et al., eds., Fourth Edition, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, New York, 2012, or Current Protocols in Molecular Biology, F.M. Ausubel, et al., eds., John Wiley & Sons, Inc., New York. Conservative substitutions of amino acids include substitutions made amongst amino acids within the Docket No. A1361.70020WO00 1410150.1following groups: (a) M, I, L, V; (b) F, Y, W; (c) K, R, H; (d) A, G; (e) S, T; (f) Q, N; and (g) E, D.

[0059] Cross-reactive: As used herein and in the context of a targeting agent (e.g., antibody), the term “cross-reactive,” refers to a property of the agent being capable of specifically binding to more than one antigen of a similar type or class (e.g., antigens of multiple homologs, paralogs, or orthologs) with similar affinity or avidity.

[0060] Cytotoxic agent: As used herein, the term "cytotoxic agent" refers to a substance that inhibits or prevents a cellular function and / or causes cell death or destruction. Such agents are well known in the art, and include, e.g., radioactive isotopes (e.g., At211, I131, I125, Y90, Re186, Re188, Sm153, Bi212, P32, Pb212and radioactive isotopes of Lu); chemotherapeutic agents or drugs (e.g., methotrexate, adriamycin, vinca alkaloids (vincristine, vinblastine, etoposide), doxorubicin, melphalan, mitomycin C, chlorambucil, daunorubicin, or other intercalating agents); growth inhibitory agents; enzymes and fragments thereof, such as nucleolytic enzymes; antibiotics; toxins such as small molecule toxins or enzymatically active toxins of bacterial, fungal, plant or animal origin, including fragments and / or variants thereof; and the various anti-tumor or anti-cancer agents described below.

[0061] Effective Amount: As used herein, “an effective amount” refers to the amount of each active agent (e.g., anti-WT1 / HLA-A2 antibody) required to confer a desired effect (e.g., a therapeutic effect on the subject), either alone or in combination with one or more other active agents. In some embodiments, the therapeutic effect is reduced WT1 level or activity and / or alleviated disease conditions (e.g., treatment of a WT1-expressing cancer and / or reduction of WT1-expressing tumor size).

[0062] Framework: As used herein, the term “framework” or “framework sequence” refers to the remaining sequences of a variable region minus the CDRs. Because the exact definition of a CDR sequence can be determined by different systems, the meaning of a framework sequence is subject to correspondingly different interpretations. The six CDRs (LC CDR1, LC CDR2, and LC CDR3 of light chain and HC CDR1, HC CDR2, and HC CDR3 of heavy chain) also divide the framework regions on the light chain and the heavy chain into four sub-regions (FR1, FR2, FR3 and FR4) on each chain, in which CDR1 is positioned between FR1 and FR2, CDR2 between FR2 and FR3, and CDR3 between FR3 and FR4. Without specifying the particular sub-regions as FR1, FR2, FR3 or FR4, a framework region, as referred to by others, represents the combined FRs within the variable region of a single, naturally occurring immunoglobulin chain. As used herein, a FR represents Docket No. A1361.70020WO00 1410150.1one of the four sub-regions, and FRs represents two or more of the four sub-regions constituting a framework region. Human heavy chain and light chain acceptor sequences are known in the art. In one embodiment, the acceptor sequences known in the art may be used in antibodies disclosed herein.

[0063] Human antibody: The term "human antibody", as used herein, is intended to include antibodies having variable and constant regions derived from human germline immunoglobulin sequences. The human antibodies of the disclosure may include amino acid residues not encoded by human germline immunoglobulin sequences (e.g., mutations introduced by random or site-specific mutagenesis in vitro or by somatic mutation in vivo), for example in the CDRs and in particular CDR3. However, the term "human antibody", as used herein, is not intended to include antibodies in which CDR sequences derived from the germline of another mammalian species, such as a mouse, have been grafted onto human framework sequences.

[0064] Humanized antibody: The term "humanized antibody" refers to antibodies which comprise heavy and light chain variable region sequences from a non-human species (e.g., a mouse) but in which at least a portion of the VH and / or VL sequence has been altered to be more "human-like", i.e., more similar to human germline variable sequences. One type of humanized antibody is a CDR-grafted antibody, in which human CDR sequences are introduced into non-human VH and VL sequences to replace the corresponding nonhuman CDR sequences. In one embodiment, humanized anti-WT1 / HLA-A2 antibodies and antigen binding portions are provided. Such antibodies may be generated by obtaining murine anti- WT1 monoclonal antibodies using traditional hybridoma technology followed by humanization using in vitro genetic engineering, such as those disclosed in Kasaian et al PCT publication No. WO 2005 / 123126 A2.

[0065] Humanized antibodies are human immunoglobulins (recipient antibody) in which residues from a complementary determining region (CDR) of the recipient are replaced by residues from a CDR of a non-human species (donor antibody) such as mouse, rat, or rabbit having the desired specificity, affinity, and capacity. In some embodiments, Fv framework region (FR) residues of the human immunoglobulin are replaced by corresponding non- human residues. Furthermore, the humanized antibody may comprise residues that are found neither in the recipient antibody nor in the imported CDR or framework sequences, but are included to further refine and optimize antibody performance. In general, the humanized antibody will comprise substantially all of at least one, and typically two, variable domains, Docket No. A1361.70020WO00 1410150.1in which all or substantially all of the CDR regions correspond to those of a non-human immunoglobulin and all or substantially all of the FR regions are those of a human immunoglobulin consensus sequence. The humanized antibody optimally also will comprise at least a portion of an immunoglobulin constant region or domain (Fc), typically that of a human immunoglobulin. Antibodies may have Fc regions modified as described in WO 99 / 58572. Other forms of humanized antibodies have one or more CDRs (one, two, three, four, five, six) which are altered with respect to the original antibody, which are also termed one or more CDRs derived from one or more CDRs from the original antibody. Humanized antibodies may also involve affinity maturation.

[0066] In some embodiments, humanization is achieved by grafting the CDRs (e.g., as shown in Table 1) into the human variable domains (e.g., IGKV1-NL1*01 and IGHV1-3*01 human variable domain). In some embodiments, the anti-WT1 / HLA-A2 antibody of the present disclosure is a humanized variant comprising one or more amino acid substitutions (e.g., in the VH framework region) as compared with any one of the VHs listed in Table 1, and / or one or more amino acid substitutions (e.g., in the VL framework region) as compared with any one of the VLs listed in Table 1.

[0067] Isolated antibody: An "isolated antibody", as used herein, is intended to refer to an antibody that is substantially free of other antibodies having different antigenic specificities (e.g., an isolated antibody that specifically binds WT1 / HLA-A2 is substantially free of antibodies that specifically bind antigens other than WT1 / HLA-A2). In some embodiments, an isolated antibody that specifically binds WT1 / HLA-A2 does not demonstrate cross-reactivity to other antigens. Moreover, an isolated antibody may be substantially free of other cellular material and / or chemicals.

[0068] Kabat numbering: The terms "Kabat numbering", "Kabat definitions” and "Kabat labeling" are used interchangeably herein. These terms, which are recognized in the art, refer to a system of numbering amino acid residues which are more variable (i.e. hypervariable) than other amino acid residues in the heavy and light chain variable regions of an antibody, or an antigen binding portion thereof (Kabat et al. (1971) Ann. NY Acad, Sci. 190:382-391 and, Kabat, E. A., et al. (1991) Sequences of Proteins of Immunological Interest, Fifth Edition, U.S. Department of Health and Human Services, NIH Publication No. 91-3242). For the heavy chain variable region, the hypervariable region ranges from amino acid positions 31 to 35 for CDR1, amino acid positions 50 to 65 for CDR2, and amino acid positions 95 to 102 for CDR3. For the light chain variable region, the hypervariable region ranges from amino Docket No. A1361.70020WO00 1410150.1acid positions 24 to 34 for CDR1, amino acid positions 50 to 56 for CDR2, and amino acid positions 89 to 97 for CDR3.

[0069] Multispecific Antibody: As used herein, the term “multispecific antibody” refers to a polypeptide or a complex (e.g., two or more covalently linked polypeptides) that includes at least two (e.g. two, three, or four) different immunoglobulin variable domains or at least two different sites, e.g., paratopes, that specifically bind to one or more antigens. For example, in one embodiment, a multispecific antibody is a polypeptide that includes at least two (e.g. two, three, or four) different sites in which each site binds to a different epitope of the same antigen. In other embodiments, a multispecific antibody is a polypeptide that includes at least two (e.g. two, three, or four) different sites in which each site binds to a different antigen. In some embodiments, an antigen to which a site of a multispecific antibody specifically binds is a complex (e.g., a peptide complexed with a single chain HLA- A2 molecule).

[0070] Recombinant antibody: The term "recombinant antibody", as used herein, is intended to include all antibodies that are prepared, expressed, created or isolated by recombinant means, such as antibodies expressed using a recombinant expression vector transfected into a host cell (described in more details in this disclosure), including, for example, antibodies isolated from a recombinant, combinatorial human antibody library (Hoogenboom H. R., (1997) TIB Tech. 15:62-70; Azzazy H., and Highsmith W. E., (2002) Clin. Biochem. 35:425-445; Gavilondo J. V., and Larrick J. W. (2002) BioTechniques 29:128- 145; Hoogenboom H., and Chames P. (2000) Immunology Today 21:371-378), antibodies isolated from an animal (e.g., a mouse) that is transgenic for human immunoglobulin genes (see e.g., Taylor, L. D., et al. (1992) Nucl. Acids Res. 20:6287-6295; Kellermann S-A., and Green L. L. (2002) Current Opinion in Biotechnology 13:593-597; Little M. et al (2000) Immunology Today 21:364-370) or antibodies prepared, expressed, created or isolated by any other means that involves splicing of human immunoglobulin gene sequences to other DNA sequences. In some embodiments, recombinant human antibodies are provided herein. In certain embodiments, such recombinant human antibodies have variable and constant regions derived from human germline immunoglobulin sequences. In certain embodiments, however, such recombinant human antibodies are subjected to in vitro mutagenesis (or, when an animal transgenic for human Ig sequences is used, in vivo somatic mutagenesis) and thus the amino acid sequences of the VH and VL regions of the recombinant antibodies are sequences that, while derived from and related to human germline VH and VL sequences, may not naturally Docket No. A1361.70020WO00 1410150.1exist within the human antibody germline repertoire in vivo. One embodiment of the disclosure provides fully human antibodies capable of binding human WT1 / HLA-A2 which can be generated using techniques well known in the art, such as, but not limited to, using human Ig phage libraries such as those disclosed in Jermutus et al., PCT publication No. WO 2005 / 007699 A2.

[0071] Selective: As used herein, the term “selective” or “selectively” refers to the ability of a molecule to produce an effect (e.g., inhibit, antagonize, agonize, etc.) in relation to its target molecule compared to a reference molecule. For example, a molecule that selectively inhibits its target molecule means that this molecule is capable of inhibiting its target molecule to a degree that is distinguishable from a reference molecule in an inhibition assay or other inhibitory context. For example, with respect to an inhibitor, the term, “selectively inhibits”, refers to the ability of the inhibitor to inhibit its target molecule with a degree that is distinguishable from a reference molecule that is not substantially inhibited in an inhibition assay, e.g., to an extent that permit selective inhibition of the target molecule, as described herein. Once the reaction is terminated, the signal produced by inhibiting the target molecule can be measured. The half maximal inhibitor concentration for the target molecule and the reference molecule can be calculated. In some embodiments, a molecule described herein selectively binds to a target molecule. In some embodiments, a molecule described herein selectively binds WT1 / HLA-A2. In some embodiments, a molecule described herein directs a T cell to target an WT1 / HLA-A2-expressing cell. In some embodiments, a molecule described herein binds to WT1 / HLA-A2 to induce killing of WT1 / HLA-A2 expressing cells, e.g., WT1 / HLA-A2 expressing tumor cells.

[0072] Specifically binds: As used herein, the term “specifically binds” refers to the ability of a molecule to bind to a binding partner with a degree of affinity or avidity that enables the molecule to be used to distinguish the binding partner from an appropriate control in a binding assay or other binding context. With respect to an antibody, the term, “specifically binds”, refers to the ability of an antibody to bind to a specific antigen with a degree of affinity or avidity, compared with an appropriate reference antigen or antigens, which enables the antibody to be used to distinguish the specific antigen from others, as described herein. In some embodiments, an antibody specifically binds to a target if the antibody has a KDfor binding the target of at least about 10-4M, 10-5M, 10-6M, 10-7M, 10-8M, 10-9M, 10-10M, 10-11M, 10-12M, 10-13M, or less. In some embodiments, an antibody specifically binds a WT1 peptide bound by HLA-A2. Docket No. A1361.70020WO00 1410150.1

[0073] Subject: As used herein, the term “subject” refers to a mammal. In some embodiments, a subject is a human. In some embodiments, a subject is a patient, e.g., a human patient that has or is suspected of having a disease. In some embodiments, the subject is a human patient who has or is suspected of having a WT1-expressing cancer or tumor and / or one or more conditions arising as a result of a WT1-expressing cancer or tumor.

[0074] Treatment: As used herein, the term “treating” or “treatment” refers to the application or administration of a composition including one or more active agents (e.g., anti WT1 / HLA-A2 antibodies) to a subject, who has a target disease or disorder (e.g., cancer expressing WT1), a symptom of the disease / disorder, or a predisposition toward the disease / disorder, with the purpose to cure, heal, alleviate, relieve, alter, remedy, ameliorate, improve, or affect the disorder, the symptom of the disease, or the predisposition toward the disease or disorder. Alleviating a target disease / disorder includes delaying or preventing the development or progression of the disease, or reducing disease severity.

[0075] Wilms’ tumor 1 (WT1): Wilms' tumor 1 (WT1) protein is a transcription factor that plays a critical role in the development of various tissues in the human body, especially the kidneys and gonads. Outside of homeostatic processes, WT1 is a cancer-associated antigen. Mutations in the gene encoding WT1 can result in the development of Wilms’ tumor, and WT1 over-expression is observed in a number of cancers (e.g., pediatric kidney cancer). Because WT1 is a transcription factor, it is typically a strictly intracellular protein, but in cancer cells, WT1 is intracellularly processed such that fragments of the protein are presented on MHC-I molecules on the cell surfaces, forming WT1 / HLA-A2 complexes in humans. II. Antibodies and Related Compositions (a) Anti-WT1 / HLA-A2 Antibodies

[0076] In some embodiments, the anti-WT1 / HLA-A2 antibody is an antibody specific for a WT1 / HLA-A2 complex. Provided herein, in some aspects, are antibodies that bind to human WT1 / HLA-A2 with high specificity and affinity. In some embodiments, the anti-WT1 / HLA- A2 antibody described herein specifically binds to any extracellular epitope of a WT1 / HLA- A2 or an epitope that becomes exposed to an antibody. In some embodiments, anti- WT1 / HLA-A2 antibodies provided herein bind to human WT1 / HLA-A2. In some embodiments, the anti-WT1 / HLA-A2 antibody described herein binds to an amino acid segment of a human. WT1 is a transcription factor involved in organ development but is also over-expressed in a number of cancers. WT1 is a strictly intracellular protein under normal Docket No. A1361.70020WO00 1410150.1circumstances, but in cancer cells, it is processed in the proteosome and displayed on MHC or HLA molecules on the cancer cell surface, forming a WT1 / MHC complex (e.g., a WT1 / MHC-I complex) or a WT1 / HLA complex (e.g., a WT1 / HLA-A2 complex). Such complexes can be recognized by immune cells, including T effector cells.

[0077] In some embodiments, the anti-WT1 / HLA-A2 antibody described herein specifically binds to a human WT1 bound by HLA-A2. Exemplary amino acid sequence of human WT1 is set forth in NCBI Accession Number BAR92607.1.

[0078] Human WT1 amino acid sequence (SEQ ID NO: 17): MGSDVRDLNALLPAVPSLGGGGGCALPVSGAAQWAPVLDFAPPGASAYGSLGGPAPPPAPPPPPPPPP HSFIKQEPSWGGAEPHEEQCLSAFTVHFSGQFTGTAGACRYGPFGPPPPSQASSGQARMFPNAPYLPS CLESQPAIRNQGYSTVTFDGTPSYGHTPSHHAAQFPNHSFKHEDPMGQQGSLGEQQYSVPPPVYGCHT PTDSCTGSQALLLRTPYSSDNLYQMTSQLECMTWNQMNLGATLKGVAAGSSSSVKWTEGQSNHSTGYE SDNHTTPILCGAQYRIHTHGVFRGIQDVRRVPGVAPTLVRSASETSEKRPFMCAYPGCNKRYFKLSHL QMHSRKHTGEKPYQCDFKDCERRFSRSDQLKRHQRRHTGVKPFQCKTCQRKFSRSDHLKTHTRTHTGK TSEKPFSCRWPSCQKKFARSDELVRHHNMHQRNMTKLQLAL

[0079] In some embodiments, the anti-WT1 / HLA-A2 antibody is an antibody specific for WT1 / HLA-A2. Provided herein, in some aspects, are antibodies that bind to human WT1 / HLA-A2 with high specificity and affinity. In some embodiments, the anti-WT1 / HLA- A2 antibody described herein specifically binds to any extracellular epitope of a WT1 / HLA- A2 or an epitope that becomes exposed to an antibody. WT1 is a transcription factor that was previously identified as a tumor suppressor gene, as mutations in the WT1 gene are associated with certain cancers, but in normal contexts, WT1 / HLA-A2 activates or represses different genes to direct the development of organs during embryogenesis and maintain certain tissues in adulthood. In cancer cells, WT1 is presented on the cell surface as a complex with MHC class I (e.g., as a WT1 / HLA-A2 complex). An exemplary WT1 sequence is provided below in Table 4. One challenge of designing antibodies specific to a WT1 peptide is that the immunodominant WT1 peptide has high homology to peptides belonging to other, endogenous proteins, e.g., M13L or PIGQ (also provided in Table 4). Table 4. Sequences of WT1 and off-target peptides, M13L and PIGQ Peptide Name SequenceDocket No. A1361.70020WO00 1410150.1

[0080] An anti-WT1 / HLA-A2 antibody provided herein bind WT1 complexes with high specificity, thus avoiding off-target binding and the associated ill effects.

[0081] In some embodiments, the anti-WT1 / HLA-A2 antibody described herein may bind to a fragment of a human WT1 / HLA-A2. The fragment of WT1 / HLA-A2 may be between about 5 and about 425 amino acids, between about 10 and about 400 amino acids, between about 50 and about 350 amino acids, between about 100 and about 300 amino acids, between about 150 and about 250 amino acids, between about 200 and about 300 amino acids, or between about 75 and about 150 amino acids in length. The fragment may comprise a contiguous number of amino acids from WT1 / HLA-A2. In some embodiments, the anti- WT1 / HLA-A2 antibody specifically binds an HLA-A2 (e.g., HLA-A*0201)-restricted fragment of WT1 comprising the amino acid sequence RMFPNAPYL (SEQ ID NO: 75). In some embodiments, the anti-WT1 / HLA-A2 antibody specifically binds a fragment of WT1 comprising the amino acid sequence RMFPNAPYL (SEQ ID NO: 75) that is bound to an HLA-A2 molecule (e.g., HLA-A*0201).

[0082] In some embodiments, an anti-WT1 / HLA-A2 antibody described herein are affinity matured clones. In some embodiments, an anti-WT1 / HLA-A2 antibody specifically binds a WT1 / HLA-A2 (e.g., a human WT1 / HLA-A2) with binding affinity (e.g., as indicated by KD) of at least about 10-4M, 10-5M, 10-6M, 10-7M, 10-8M, 10-9M, 10-10M, 10-11M, 10-12M, 10-13M, or less. For example, an anti-WT1 / HLA-A2 antibody of the present disclosure can bind to a WT1 / HLA-A2 protein (e.g., human WT1 / HLA-A2) with an affinity between 5 pM and 500 nM, between 50 pM and 100 nM, between 500 pM and 50 nM, between 1 nM and 50 nM, between 2 nM and 20 nM, between 1 nM and 10 nM, between 1 nM and 3 nM, or between 2 nM and 5 nM. The disclosure also includes antibodies that compete with any of the antibodies described herein for binding to a WT1 / HLA-A2 protein (e.g., human WT1 / HLA-A2) and that have an affinity of 100 nM or lower (e.g., 80 nM or lower, 50 nM or lower, 20 nM or lower, 10 nM or lower, 5 nM or lower, 500 pM or lower, 50 pM or lower, or 5 pM or lower). The affinity and binding kinetics of the anti-WT1 / HLA-A2 antibody can be tested using any suitable method including but not limited to biosensor technology (e.g., OCTET or BIACORE). In some embodiments, an anti-WT1 / HLA-A2 antibody described herein binds to WT1 / HLA-A2 with a KDof sub-nanomolar range or single-digit nanomolar range.

[0083] Binding affinity (or binding specificity) can be determined by a variety of methods including equilibrium dialysis, equilibrium binding, gel filtration, ELISA, surface plasmon Docket No. A1361.70020WO00 1410150.1resonance (SPR), florescent activated cell sorting (FACS) or spectroscopy (e.g., using a fluorescence assay). Exemplary conditions for evaluating binding affinity are in HBS-P buffer (10 mM HEPES pH7.4, 150 mM NaCl, 0.005% (v / v) surfactant P20) and PBS buffer (10mM PO4-3, 137mM NaCl, and 2.7mM KCl). These techniques can be used to measure the concentration of bound proteins as a function of target protein concentration. The concentration of bound protein ([[Bound]]) is generally related to the concentration of free target protein ([[Free]]) by the following equation: [[Bound]] = [[Free]] / (Kd+[[Free]])

[0084] It is not always necessary to make an exact determination of KA, though, since sometimes it is sufficient to obtain a quantitative measurement of affinity, e.g., determined using a method such as ELISA or FACS analysis, is proportional to KA, and thus can be used for comparisons, such as determining whether a higher affinity is, e.g., 2-fold higher, to obtain a qualitative measurement of affinity, or to obtain an inference of affinity, e.g., by activity in a functional assay, e.g., an in vitro or in vivo assay.

[0085] In some embodiments, an antibody is a full-length IgG, a Fab fragment, a F(ab’) fragment, a scFv, or a Fv. In some embodiments, an antibody comprises a heavy chain constant region of the isotype IgG1, IgG2, IgG3, or IgG4.

[0086] The heavy chain variable domain (VH) and light chain variable domain (VL), CDR sequences, and heavy chain and light chain constant region sequences of non-limiting examples of anti-WT1 antibodies are provided in Table 1. Table 1. Examples of anti-WT1 / HLA-A2 binders (CDRs according to the Kabat definition) anti-WT1 / HLA-A2 binderSequences SEQ ID NODocket No. A1361.70020WO00 1410150.1VHQVQLQESGPGLVKPSETLSLTCTVSGGSISGYYWSWIRQP 14 PGKGLEWIGEIYHSGSTNYNPSLKSRVTISVDKSKNQFSLDocket No. A1361.70020WO00 1410150.1LC CDR2AASSLQS5LC CDR3 89Table 5 Consensus Sequences for Antibodies #1 - #8 Antibody Structure Consensus SequenceDocket No. A1361.70020WO00 1410150.1X is P, Q, or F X i Y L ETable 6 Consensus Sequences for Antibodies #1 - #6 Antibody Structure Consensus Sequence SEQ ID NOTable 7 Consensus Sequences for Antibodies #7 - #8 Antibody Structure Consensus Sequence SEQ ID NODocket No. A1361.70020WO00 1410150.1Consensus sequence LC CDR2AASSX QS97 C n n n LC CDR3 98

[0087] In some embodiments, an anti-WT1 / HLA-A2 antibody of the present disclosure comprises one or more of the HC CDRs (e.g., HC CDR1, HC CDR2, or HC CDR3) amino acid sequences from any one of an anti-WT1 / HLA-A2 antibody selected from Table 1. In some embodiments, an anti-WT1 / HLA-A2 antibody of the present disclosure comprise the HC CDR1, HC CDR2, and HC CDR3 as provided for any one of the antibodies elected from Table 1. In some embodiments, the present disclosure provides an antibody that specifically binds WT1 / HLA-A2 complex, wherein the improvement comprises the HC CDR1, HC CDR2, and HC CDR3 as provided for any one of the antibodies elected from Table 1. In some embodiments, the present disclosure provides an antibody that specifically binds WT1 / HLA-A2 complex, wherein the improvement comprises one or more of the LC CDRs (e.g., LC CDR1, LC CDR2, or LC CDR3) amino acid sequences from any one of an anti- WT1 / HLA-A2 antibody selected from Table 1. In some embodiments, the present disclosure provides an antibody that specifically binds WT1 / HLA-A2 complex, wherein the improvement comprises the LC CDR1, LC CDR2, and LC CDR3 s provided for any one of an anti-WT1 / HLA-A2 antibody selected from Table 1. In some embodiments, the present disclosure provides an antibody that specifically binds WT1 / HLA-A2 complex, wherein the improvement comprises HC CDR1, HC CDR2, and HC CDR3, LC CDR1, LC CDR2, and LC CDR3 as provided for any one of an anti-WT1 / HLA-A2 antibody selected from Table 1.

[0088] In some embodiments, an anti-WT1 / HLA-A2 antibody of the present disclosure comprises one or more of the LC CDRs (e.g., LC CDR1, LC CDR2, or LC CDR3) amino acid sequences from any one of an anti-WT1 / HLA-A2 antibody selected from Table 1. In some embodiments, an anti-WT1 / HLA-A2 antibody of the present disclosure comprise the LC CDR1, LC CDR2, and LC CDR3 s provided for any one of the anti-WT1 antibodies selected from Table 1. In some embodiments, the present disclosure provides an antibody that specifically binds a WT1 / HLA-A2 complex, wherein the improvement comprises the HC CDR1, HC CDR2, HC CDR3, LC CDR1, LC CDR2, and LC CDR3 as provided for any one of an anti-WT1 / HLA-A2 antibody selected from Table 1.

[0089] In some embodiments, an anti-WT1 / HLA-A2 antibody of the present disclosure comprises the HC CDR1, HC CDR2, HC CDR3, LC CDR1, LC CDR2, and LC CDR3 as provided for any one of an anti-WT1 / HLA-A2 antibody selected from Table 1. In some embodiments, antibody heavy and light chain CDR3 domains may play a particularly Docket No. A1361.70020WO00 1410150.1important role in the binding specificity / affinity of an antibody for an antigen. Accordingly, an anti-WT1 / HLA-A2 antibody of the disclosure may include at least the heavy and / or light chain CDR3s of any one of an anti-WT1 / HLA-A2 antibody selected from Table 1.

[0090] In some embodiments, an anti-WT1 / HLA-A2 antibody of the present disclosure comprises the HC CDR1, HC CDR2, HC CDR3, LC CDR1, LC CDR2, and / or LC CDR3 of the antibody WT1 / HLA-A2 #1 antibody.

[0091] In some embodiments, an anti-WT1 / HLA-A2 antibody of the present disclosure comprises the HC CDR1, HC CDR2, HC CDR3, LC CDR1, LC CDR2, and / or LC CDR3 of the antibody WT1 / HLA-A2 #2 antibody.

[0092] In some embodiments, an anti-WT1 / HLA-A2 antibody of the present disclosure comprises the HC CDR1, HC CDR2, HC CDR3, LC CDR1, LC CDR2, and / or LC CDR3 of the antibody WT1 / HLA-A2 #3 antibody.

[0093] In some embodiments, an anti-WT1 / HLA-A2 antibody of the present disclosure comprises the HC CDR1, HC CDR2, HC CDR3, LC CDR1, LC CDR2, and / or LC CDR3 of the antibody WT1 / HLA-A2 #4 antibody.

[0094] In some embodiments, an anti-WT1 / HLA-A2 antibody of the present disclosure comprises the HC CDR1, HC CDR2, HC CDR3, LC CDR1, LC CDR2, and / or LC CDR3 of the antibody WT1 / HLA-A2 #5 antibody.

[0095] In some embodiments, an anti-WT1 / HLA-A2 antibody of the present disclosure comprises the HC CDR1, HC CDR2, HC CDR3, LC CDR1, LC CDR2, and / or LC CDR3 of the antibody WT1 / HLA-A2 #6 antibody.

[0096] In some embodiments, an anti-WT1 / HLA-A2 antibody of the present disclosure comprises the HC CDR1, HC CDR2, HC CDR3, LC CDR1, LC CDR2, and / or LC CDR3 of the antibody WT1 / HLA-A2 #7 antibody.

[0097] In some embodiments, an anti-WT1 / HLA-A2 antibody of the present disclosure comprises the HC CDR1, HC CDR2, HC CDR3, LC CDR1, LC CDR2, and / or LC CDR3 of the antibody WT1 / HLA-A2 #8 antibody.

[0098] In some embodiments, the isolated anti-WT1 / HLA-A2 antibody comprises a heavy chain variable region that comprises a heavy chain CDR1 (HC CDR1), a heavy chain CDR2 (HC CDR2), and a heavy chain CDR3 (HC CDR3).

[0099] Also within the scope of the present disclosure are functional variants of any of the exemplary anti-WT1 / HLA-A2 antibodies as disclosed herein. A functional variant may contain one or more amino acid residue variations in the VH and / or VL, or in one or more of Docket No. A1361.70020WO00 1410150.1the HC CDRs and / or one or more of the LC CDRs as relative to the reference antibody, while retaining substantially similar binding and biological activities (e.g., substantially similar binding affinity, binding specificity, inhibitory activity, anti-inflammatory activity, or a combination thereof) as the reference antibody. [000100] In some embodiments, an anti-WT1 / HLA-A2 antibody of the disclosure have one or more CDRs (e.g., HC CDR or LC CDR) sequences substantially similar to any of the HC CDR1, HC CDR2, HC CDR3, LC CDR1, LC CDR2, and / or LC CDR3 sequences from one of an anti-WT1 / HLA-A2 antibody selected from Table 1. In some embodiments, the position of one or more CDRs along the VH (e.g., HC CDR1, HC CDR2, or HC CDR3) and / or VL (e.g., LC CDR1, LC CDR2, or LC CDR3) region of an antibody described herein can vary by one, two, three, four, five, or six amino acid positions so long as immunospecific binding to WT1 / HLA-A2 (e.g., human WT1 / HLA-A2) is maintained (e.g., substantially maintained, for example, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95% of the binding of the original antibody from which it is derived). For example, in some embodiments, the position defining a CDR of any antibody described herein can vary by shifting the N-terminal and / or C-terminal boundary of the CDR by one, two, three, four, five, or six amino acids, relative to the CDR position of any one of the antibodies described herein, so long as immunospecific binding to WT1 / HLA-A2 (e.g., human WT1 / HLA-A2) is maintained (e.g., substantially maintained, for example, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95% of the binding of the original antibody from which it is derived). In another embodiment, the length of one or more CDRs along the VH (e.g., HC CDR1, HC CDR2, or HC CDR3) and / or VL (e.g., LC CDR1, LC CDR2, or LC CDR3) region of an antibody described herein can vary (e.g., be shorter or longer) by one, two, three, four, five, or more amino acids, so long as immunospecific binding to WT1 / HLA- A2 (e.g., human WT1 / HLA-A2) is maintained (e.g., substantially maintained, for example, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95% of the binding of the original antibody from which it is derived). [000101] Accordingly, in some embodiments, a HC CDR1, HC CDR2, HC CDR3, LC CDR1, LC CDR2, and / or LC CDR3 described herein may be one, two, three, four, five or more amino acids shorter than one or more of the CDRs described herein (e.g., CDRS from an anti-WT1 / HLA-A2 antibody selected from Table 1) so long as immunospecific binding to WT1 / HLA-A2 (e.g., human WT1 / HLA-A2) is maintained (e.g., substantially maintained, for example, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95% Docket No. A1361.70020WO00 1410150.1relative to the binding of the original antibody from which it is derived). In some embodiments, a HC CDR1, HC CDR2, HC CDR3, LC CDR1, LC CDR2, and / or LC CDR3 described herein may be one, two, three, four, five or more amino acids longer than one or more of the CDRs described herein (e.g., CDRS from an anti-WT1 / HLA-A2 antibody selected from Table 1) so long as immunospecific binding to WT1 / HLA-A2 (e.g., human WT1 / HLA-A2) is maintained (e.g., substantially maintained, for example, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95% relative to the binding of the original antibody from which it is derived). In some embodiments, the amino portion of a HC CDR1, HC CDR2, HC CDR3, LC CDR1, LC CDR2, and / or LC CDR3 described herein can be extended by one, two, three, four, five or more amino acids compared to one or more of the CDRs described herein (e.g., CDRS from an anti-WT1 / HLA-A2 antibody selected from Table 1) so long as immunospecific binding to WT1 / HLA-A2 (e.g., human WT1 / HLA- A2) is maintained (e.g., substantially maintained, for example, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95% relative to the binding of the original antibody from which it is derived). In some embodiments, the carboxy portion of a HC CDR1, HC CDR2, HC CDR3, LC CDR1, LC CDR2, and / or LC CDR3 described herein can be extended by one, two, three, four, five or more amino acids compared to one or more of the CDRs described herein (e.g., CDRS from an anti-WT1 / HLA-A2 antibody selected from Table 1) so long as immunospecific binding to WT1 / HLA-A2 (e.g., human WT1 / HLA-A2) is maintained (e.g., substantially maintained, for example, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95% relative to the binding of the original antibody from which it is derived). In some embodiments, the amino portion of a HC CDR1, HC CDR2, HC CDR3, LC CDR1, LC CDR2, and / or LC CDR3 described herein can be shortened by one, two, three, four, five or more amino acids compared to one or more of the CDRs described herein (e.g., CDRS from any of the anti- WT1 / HLA-A2 antibodies selected from Table 1) so long as immunospecific binding to WT1 / HLA-A2 (e.g., human WT1 / HLA-A2) is maintained (e.g., substantially maintained, for example, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95% relative to the binding of the original antibody from which it is derived). In some embodiments, the carboxy portion of a HC CDR1, HC CDR2, HC CDR3, LC CDR1, LC CDR2, and / or LC CDR3 described herein can be shortened by one, two, three, four, five or more amino acids compared to one or more of the CDRs described herein (e.g., CDRS from an anti-WT1 / HLA-A2 antibody selected from Table 1) so long as immunospecific binding to WT1 / HLA-A2 (e.g., human WT1 / HLA-A2) is maintained Docket No. A1361.70020WO00 1410150.1(e.g., substantially maintained, for example, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95% relative to the binding of the original antibody from which it is derived). Any method can be used to ascertain whether immunospecific binding to WT1 / HLA-A2 (e.g., human WT1 / HLA-A2) is maintained, for example, using binding assays and conditions described in the art. [000102] In some examples, an anti-WT1 / HLA-A2 antibody of the disclosure has one or more CDR (e.g., HC CDR or LC CDR) sequences substantially similar to any one of an anti- WT1 / HLA-A2 antibody selected from Table 1. For example, antibodies may include one or more CDR sequence(s) from an anti-WT1 / HLA-A2 antibody selected from Table 1 containing up to 5, 4, 3, 2, or 1 amino acid residue variations as compared to the corresponding CDR region in any one of the CDRs provided herein (e.g., CDRs from an anti- WT1 / HLA-A2 antibody selected from Table 1) so long as immunospecific binding to WT1 / HLA-A2 (e.g., human WT1 / HLA-A2) is maintained (e.g., substantially maintained, for example, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95% relative to the binding of the original antibody from which it is derived). In some embodiments, any of the amino acid variations in any of the CDRs provided herein may be conservative variations. Conservative variations can be introduced into the CDRs at positions where the residues are not likely to be involved in interacting with a WT1 / HLA-A2 protein (e.g., a human WT1 / HLA-A2 protein), for example, as determined based on a crystal structure. Some aspects of the disclosure provide anti-WT1 / HLA-A2 antibodies that comprise one or more of the heavy chain variable (VH) and / or light chain variable (VL) domains provided herein. In some embodiments, any of the VH domains provided herein include one or more of the HC CDR sequences (e.g., HC CDR1, HC CDR2, and HC CDR3) provided herein, for example, any of the CDR-H sequences provided in any one of the anti- WT1 / HLA-A2 selected from Table 1. In some embodiments, any of the VL domains provided herein include one or more of the CDR-L sequences (e.g., LC CDR1, LC CDR2, and LC CDR3) provided herein, for example, any of the LC CDR sequences provided in any one of an anti-WT1 / HLA-A2 antibody selected from Table 1. [000103] In some embodiments, an anti-WT1 / HLA-A2 antibody of the disclosure includes any antibody that includes a heavy chain variable domain and / or a light chain variable domain of any one of an anti-WT1 / HLA-A2 antibody selected from Table 1, and variants thereof. In some embodiments, anti-WT1 / HLA-A2 antibodies of the disclosure include any Docket No. A1361.70020WO00 1410150.1antibody that includes the heavy chain variable and light chain variable pairs of any anti-WT1 antibodies selected from Table 1. [000104] Aspects of the disclosure provide anti-WT1 / HLA-A2 antibodies having a heavy chain variable (VH) and / or a light chain variable (VL) domain amino acid sequence homologous to any of those described herein. In some embodiments, the anti-WT1 / HLA-A2 antibody comprises a heavy chain variable sequence or a light chain variable sequence that is at least 75% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to the heavy chain variable sequence and / or any light chain variable sequence of any one of an anti-WT1 / HLA-A2 antibody selected from Table 1. In some embodiments, the homologous heavy chain variable and / or a light chain variable amino acid sequences do not vary within any of the CDR sequences provided herein. For example, in some embodiments, the degree of sequence variation (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) may occur within a heavy chain variable and / or a light chain variable sequence excluding any of the CDR sequences provided herein. In some embodiments, an anti-WT1 / HLA-A2 antibody provided herein comprise a heavy chain variable sequence and a light chain variable sequence that comprises a framework sequence that is at least 75%, (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) to the framework sequence of any anti-WT1 / HLA-A2 antibodies selected from Table 1. [000105] In some embodiments, the anti-WT1 / HLA-A2 antibody of the present disclosure is a humanized antibody (e.g., a humanized variant containing one or more CDRs of Table 1). In some embodiments, the anti-WT1 / HLA-A2 antibody of the present disclosure comprises a HC CDR1, a HC CDR2, a HC CDR3, a LC CDR1, a LC CDR2, and a LC CDR3 that are the same as the HC CDR1, HC CDR2, HC CDR3, LC CDR1, LC CDR2, and LC CDR3 shown in Table 1, and comprises a humanized heavy chain variable region and / or a humanized light chain variable region. [000106] In some embodiments, the anti-WT1 / HLA-A2 antibody of the present disclosure is a humanized antibody comprising a VH containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) as compared with the VH of an anti-WT1 / HLA-A2 antibody listed in Table 1. Docket No. A1361.70020WO00 1410150.1Alternatively or in addition, the anti-WT1 / HLA-A2 antibody of the present disclosure is a humanized antibody comprising a VL containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) as compared with the VL of any one of an anti-WT1 / HLA-A2 antibody listed in Table 1. Table 8 – Antibody #1 - #8 CDR Sequences Column A Column BTable 9 – Antibody #1 – Antibody #8 VH and VL Sequences Column A Column B[000107] In some embodiments, a VH region of the present disclosure comprises HC CDR1 (or a variant thereof in which 1, 2, or 3 amino acids in HC CDR1 are substituted with another amino acid), HC CDR2 (or a variant thereof in which 1, 2, or 3 amino acids in HC CDR2 are Docket No. A1361.70020WO00 1410150.1substituted with another amino acid) and HC CDR3 (or a variant thereof in which 1, 2, or 3 amino acids in HC CDR3 are substituted with another amino acid) as indicated in: row 1, row 2, row 3, row 4, row 5, row 6, row 7, or row 8 of column A of Table 8. [000108] In some embodiments, a VH region of the present disclosure comprises at least 80%, preferably one of ≥80%, ≥85%, ≥90%, ≥91%, ≥92%, ≥93%, ≥94%, ≥95%, ≥ 96%, ≥97%, ≥98%, ≥99%, or 100% amino acid sequence identity to the amino acid sequence of a VH region sequence as indicated in row 9, row 10, row 11, row 12, row 13, row 14, row 15, or row 16 of column A of Table 9. [000109] In some embodiments, a VL region of the present disclosure comprises LC CDR1 (or a variant thereof in which 1, 2, or 3 amino acids in LC CDR1 are substituted with another amino acid), LC CDR2 (or a variant thereof in which 1, 2, or 3 amino acids in LC CDR2 are substituted with another amino acid) and LC CDR3 (or a variant thereof in which 1, 2, or 3 amino acids in LC CDR3 are substituted with another amino acid) as indicated in: row 1, row 2, row 3, row 4, row 5, row 6, row 7, or row 8 of column B of Table 8. [000110] In some embodiments, a VL region of the present disclosure comprises at least 80%, preferably one of ≥80%, ≥85%, ≥90%, ≥91%, ≥92%, ≥93%, ≥94%, ≥95%, ≥ 96%, ≥97%, ≥98%, ≥99%, or 100% amino acid sequence identity to the amino acid sequence of a VH region sequence as indicated in row 9, row 10, row 11, row 12, row 13, row 14, row 15, or row 16 of column B of Table 9. [000111] In some embodiments, an antigen-binding molecule according to the present disclosure comprises a VH region according to any one of (1), (2), (3), (4), (5), (6), (7), or (8) as described hereinabove; and a VL region according to any one of (9), (10), (11), (12), (13), (14), (15), or (16) as described hereinabove. In the following paragraph, it will be appreciated that, for example, reference to “(1) and (9)” is shorthand for “a VH region according to (1), and a VL region according (9)”. [000112] In some embodiments, an antigen-binding molecule according to the present disclosure comprises: (1) and (9); (1) and (10); (1) and (11); (1) and (12); (1) and (13); (1) and (14); (1) and (15); (1) and (16); (2) and (9); (2) and (10); (2) and (11); (2) and (12); (2) and (13); (2) and (14); (2) and (15); (2) and (16); (3) and (9); (3) and (10); (3) and (11); (3) and (12); (3) and (13); (3) and (14); (3) and (15); (3) and (16); (4) and (9); (4) and (10); (4) and (11); (4) and (12); (4) and (13); (4) and (14); (4) and (15); (4) and (16); (5) and (9); (5) and (10); (5) and (11); (5) and (12); (5) and (13); (5) and (14); (5) and (15); (5) and (16); (6) and (9); (6) and (10); (6) and (11); (6) and (12); (6) and (13); (6) and (14); (6) and (15); (6) Docket No. A1361.70020WO00 1410150.1and (16); (7) and (9); (7) and (10); (7) and (11); (7) and (12); (7) and (13); (7) and (14); (7) and (15); (7) and (16); (8) and (9); (8) and (10); (8) and (11); (8) and (12); (8) and (13); (8) and (14); (8) and (15); (8) and (16). [000113] In some embodiments, a VH region of the present disclosure comprises HC CDR1 (or a variant thereof in which 1, 2, or 3 amino acids in HC CDR1 are substituted with another amino acid), HC CDR2 (or a variant thereof in which 1, 2, or 3 amino acids in HC CDR2 are substituted with another amino acid) and HC CDR3 (or a variant thereof in which 1, 2, or 3 amino acids in HC CDR3 are substituted with another amino acid) as indicated in: row 9, row 10, row 11, row 12, row 13, row 14, row 15, or row 16 of Column A of Table 9. [000114] In some embodiments, a VH region of the present disclosure comprises at least 80%, preferably one of ≥80%, ≥85%, ≥90%, ≥91%, ≥92%, ≥93%, ≥94%, ≥95%, ≥ 96%, ≥97%, ≥98%, ≥99%, or 100% amino acid sequence identity to the amino acid sequence of a VH region sequence as indicated in row 9, row 10, row 11, row 12, row 13, row 14, row 15, or row 16 of Column A of Table 9. [000115] In some embodiments, a VL region of the present disclosure comprises LC CDR1 (or a variant thereof in which 1, 2, or 3 amino acids in LC CDR1 are substituted with another amino acid), LC CDR2 (or a variant thereof in which 1, 2, or 3 amino acids in LC CDR2 are substituted with another amino acid) and LC CDR3 (or a variant thereof in which 1, 2, or 3 amino acids in LC CDR3 are substituted with another amino acid) as indicated in: row 9, row 10, row 11, row 12, row 13, row 14, row 15, or row 16 of column B of Table 9. [000116] In some embodiments, a VH region of the present disclosure comprises at least 80%, preferably one of ≥80%, ≥85%, ≥90%, ≥91%, ≥92%, ≥93%, ≥94%, ≥95%, ≥ 96%, ≥97%, ≥98%, ≥99%, or 100% amino acid sequence identity to the amino acid sequence of a VH region sequence as indicated in row 9, row 10, row 11, row 12, row 13, row 14, row 15, or row 16 of Column A of Table 9. [000117] In some embodiments, an antigen-binding molecule according to the present disclosure comprises a VH region according to any one of (9), (10), (11), (12), (13), (14), (15), or (16), column A of Table 9 as described hereinabove; and a VL region according to any one of (9), (10), (11), (12), (13), (14), (15), or (16), column B of Table 9 as described hereinabove. In the following paragraph, it will be appreciated that, for example, reference to “(1) and (9)” is shorthand for “a VH region according to (1), and a VL region according (9)”. [000118] In some embodiments, an antigen-binding molecule according to the present disclosure comprises: (1) and (9), (1) and (10), (1) and (11), (1) and (12), (1) and (13), (1) Docket No. A1361.70020WO00 1410150.1and (14), (1) and (15), (1) and (16), (2) and (9), (2) and (10), (2) and (11), and (2) and (12), (2) and (13), (2) and (14), (2) and (15), (2) and (16), (3) and (9), (3) and (10), (3) and (11), (3) and (12), (3) and (13), (3) and (14), (3) and (15), (3) and (16), (4) and (9), (4) and (10), (4) and (11), (4) and (12), (4) and (13), (4) and (14), (4) and (15), (4) and (16), and (5) and (9), (5) and (10), (5) and (11), (5) and (12), (5) and (13), (5) and (14), (5) and (15), (5) and (16), (6) and (9), (6) and (10), (6) and (11), (6) and (12), (6) and (13), (6) and (14), (6) and (15), (6) and (16), (7) and (9), (7) and (10), (7) and (11), (7) and (12), (7) and (13), (7) and (14), (7) and (15), (7) and (16), (8) and (9), (8) and (10), (8) and (11), (8) and (12), (8) and (13), (8) and (14), (8) and (15), or (8) or (16). [000119] In some embodiments, an anti-WT1 / HLA-A2 antibody of the present disclosure comprises a HC CDR1, HC CDR2 and HC CDR3 of a heavy chain variable domain (VH) having the amino acid sequence of antibody #1 in row 9; antibody #2 in row 10, antibody #3 in row 11, antibody #4 in row 12, antibody #5 in row 13, antibody #6 in row 14, antibody #7 in row 15, or antibody #8 in row 16, column A of Table 9. Alternatively or in addition, an anti-WT1 / HLA-A2 antibody of the present disclosure comprises a LC CDR1, LC CDR2 and LC CDR3 of a heavy chain variable domain (VL) having the amino acid sequence of antibody #1 in row 9; antibody #2 in row 10, antibody #3 in row 11, antibody #4 in row 12, antibody #5 in row 13, antibody #6 in row 14, antibody #7 in row 15, antibody #8 in row 16, column B of Table 9. [000120] In some embodiments, an anti-WT1 / HLA-A2 antibody of the present disclosure comprises a HC CDR1, a HC CDR2, a HC CDR3, a LC CDR1, a LC CDR2, and a LC CDR3 having the amino acid sequences of antibody #1 in row 1, antibody #2 in row 2, antibody #3 in row 3, antibody #4 in row 4, antibody #5 in row 5, antibody #6 in row 6, antibody #7 in row 7, or antibody #8 in row 8, columns A and B of Table 8. [000121] In some embodiments, an anti-WT1 / HLA-A2 antibody of the present disclosure comprises a HC CDR1, a HC CDR2, and a HC CDR3, which collectively contains no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation) as compared with the HC CDR1, the HC CDR2, and the HC CDR3 amino acid sequences of antibody #1 in row 1, antibody #2 in row 2, antibody #3 in row 3, antibody #4 in row 4, antibody #5 in row 5, antibody #6 in row 6, antibody #7 in row 7, or antibody #8 in row 8, column A of Table 8. “Collectively,” as used anywhere in the present disclosure, means that the total number of amino acid variations in all of the three heavy chain CDRs is within the defined range. Alternatively or in addition, the anti-WT1 / HLA-A2 antibody of the present Docket No. A1361.70020WO00 1410150.1disclosure comprises a LC CDR1, a LC CDR2, and a LC CDR3, which collectively contains no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2 or 1 amino acid variation) as compared with the LC CDR1, the LC CDR2, and the LC CDR3 amino acid sequences of antibody #1 in row 1, antibody #2 in row 2, antibody #3 in row 3, antibody #4 in row 4, antibody #5 in row 5, antibody #6 in row 6, antibody #7 in row 7, or antibody #8 in row 8, column B of Table 8. [000122] In some embodiments, an anti-WT1 / HLA-A2 antibody of the present disclosure comprises a HC CDR1, a HC CDR2, and a HC CDR3 that collectively are at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to the HC CDR1, the HC CDR2, and the HC CDR3 amino acid sequences of antibody #1 in row 1, antibody #2 in row 2, antibody #3 in row 3, antibody #4 in row 4, antibody #5 in row 5, antibody #6 in row 6, antibody #7 in row 7, or antibody #8 in row 8, column A of Table 8. Alternatively or in addition, the anti-WT1 / HLA-A2 antibody of the present disclosure comprises a LC CDR1, a LC CDR2, and a LC CDR3 that collectively are at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to the LC CDR1, the LC CDR2, and the LC CDR3 amino acid sequences of antibody #1 in row 1, antibody #2 in row 2, antibody #3 in row 3, antibody #4 in row 4, antibody #5 in row 5, antibody #6 in row 6, antibody #7 in row 7, or antibody #8 in row 8, column B of Table 8. [000123] In some embodiments, an anti-WT-1 / HLA-A2 antibody of the present disclosure comprises: a HC CDR1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation), a HC CDR2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation), and / or a HC CDR3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) as compared with the HC CDR1, the HC CDR2, and the HC CDR3 amino acid sequences of antibody #1 in row 1, antibody #2 in row 2, antibody #3 in row 3, antibody #4 in row 4, antibody #5 in row 5, antibody #6 in row 6, antibody #7 in row 7, or antibody #8 in row 8, column A of Table 8. Alternatively or in addition, the anti-WT1 / HLA-A2 antibody of the present disclosure comprises: a LC CDR1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) a LC CDR2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation), and / or a LC CDR3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) as compared with the LC Docket No. A1361.70020WO00 1410150.1CDR1, the LC CDR2, and the LC CDR3 amino acid sequences of antibody #1 in row 1, antibody #2 in row 2, antibody #3 in row 3, antibody #4 in row 4, antibody #5 in row 5, antibody #6 in row 6, antibody #7 in row 7, or antibody #8 in row 8, column B of Table 8. [000124] In some embodiments, an anti-WT1 / HLA-A2 antibody of the present disclosure comprises: a HC CDR1 that is at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to the HC CDR1, a HC CDR2 that is at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to the HC CDR2 and / or a HC CDR3 that is at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to the HC CDR3 amino acid sequence of antibody #1 in row 1, antibody #2 in row 2, antibody #3 in row 3, antibody #4 in row 4, antibody #5 in row 5, antibody #6 in row 6, antibody #7 in row 7, or antibody #8 in row 8, column A of Table 8. Alternatively or in addition, the anti-WT1 / HLA-A2 antibody of the present disclosure comprises: a LC CDR1 that is at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to the LC CDR1; a LC CDR2 that is at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to the LC CDR2; and / or a LC CDR3 that is at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to the LC CDR3 amino acid sequence of antibody #1 in row 1, antibody #2 in row 2, antibody #3 in row 3, antibody #4 in row 4, antibody #5 in row 5, antibody #6 in row 6, antibody #7 in row 7, or antibody #8 in row 8, column B of Table 8. [000125] In some embodiments, an anti-WT1 / HLA-A2 antibody of the present disclosure comprises a VH comprising the amino acid sequence of antibody #1 in row 9; antibody #2 in row 10, antibody #3 in row 11, antibody #4 in row 12, antibody #5 in row 1, antibody #6 in row 14, antibody #7 in row 15, antibody #8 in row 16, column A of Table 9. Alternatively or in addition, the anti-WT1 / HLA-A2 antibody of the present disclosure comprises a VL comprising the amino acid sequence of antibody #1 in row 9; antibody #2 in row 10, antibody Docket No. A1361.70020WO00 1410150.1#3 in row 11, antibody #4 in row 12, antibody #5 in row 13, antibody #6 in row 14, antibody #7 in row 15, antibody #8 in row 16, column B of Table 9. [000126] In some embodiments, the anti-WT1 / HLA-A2 antibody of the present disclosure comprises a VH containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) as compared with the VH amino acid sequence of antibody #1 in row 9; antibody #2 in row 10, antibody #3 in row 11, antibody #4 in row 12, antibody #5 in row 13, antibody #6 in row 14, antibody #7 in row 15, antibody #8 in row 16, column A of Table 9. Alternatively or in addition, the anti-WT1 / HLA-A2 antibody of the present disclosure comprises a VL containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) as compared with the VL amino acid sequence of antibody #1 in row 9; antibody #2 in row 10, antibody #3 in row 11, antibody #4 in row 12, antibody #5 in row 13, antibody #6 in row 14, antibody #7 in row 15, antibody #8 in row 16, column B of Table 9. In some embodiments, the number of amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) may occur within a VH amino acid sequence of antibody #1 in row 9; antibody #2 in row 10, antibody #3 in row 11, antibody #4 in row 12, antibody #5 in row 13, antibody #6 in row 14, antibody #7 in row 15, antibody #8 in row 16, column A of Table 9 and / or a VL amino acid sequence of antibody #1 in row 9; antibody #2 in row 10, antibody #3 in row 11, antibody #4 in row 12, antibody #5 in row 13, antibody #6 in row 14, antibody #7 in row 15, antibody #8 in row 16, column B of Table 9 excluding any of the CDR sequences therein. [000127] In some embodiments, an anti-WT1 / HLA-A2 antibody provided herein comprise a heavy chain variable sequence that comprises a framework sequence that that contains no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation to the framework sequence of a VH amino acid sequence of antibody #1 in row 9; antibody #2 in row 10, antibody #3 in row 11, antibody #4 in row 12, antibody #5 in row 13, antibody #6 in row 14, antibody #7 in row 15, antibody #8 in row 16, column A of Table 9, and / or a light chain variable sequence that comprises a framework sequence that that contains no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation to the framework sequence of a VL amino acid sequence of antibody #1 in row 9; antibody #2 in row 10, antibody #3 in row 11, antibody #4 in row 12, antibody #5 in row 13, antibody #6 in row 14, antibody #7 in row 15, antibody #8 in row 16, column B of Table 9. Docket No. A1361.70020WO00 1410150.1[000128] In some embodiments, the anti-WT1 / HLA-A2 antibody of the present disclosure comprises a VH comprising an amino acid sequence that is at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to the VH amino acid sequence of antibody #1 in row 9; antibody #2 in row 10, antibody #3 in row 11, antibody #4 in row 12, antibody #5 in row 13, antibody #6 in row 14, antibody #7 in row 15, antibody #8 in row 16, column A of Table 9. [000129] Alternatively or in addition, the anti-WT1 / HLA-A2 antibody of the present disclosure comprises a VL comprising an amino acid sequence that is at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to the VL antibody #1 in row 9; antibody #2 in row 10, antibody #3 in row 11, antibody #4 in row 12, antibody #5 in row 13, antibody #6 in row 14, antibody #7 in row 15, antibody #8 in row 16, column B of Table 9. [000130] In some embodiments, the degree of sequence variation (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) may occur within a VH of antibody #1 in row 9; antibody #2 in row 10, antibody #3 in row 11, antibody #4 in row 12, antibody #5 in row 13, antibody #6 in row 14, antibody #7 in row 15, antibody #8 in row 16, column A of Table 9, and / or a VL of antibody #1 in row 9; antibody #2 in row 10, antibody #3 in row 11, antibody #4 in row 12, antibody #5 in row 13, antibody #6 in row 14, antibody #7 in row 15, antibody #8 in row 16, column B of Table 9 excluding any of the CDR sequences therein. [000131] In some embodiments, an anti-WT1 / HLA-A2 antibody provided herein comprise a heavy chain variable sequence that is at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to the framework sequence of a VH of antibody #1 in row 9; antibody #2 in row 10, antibody #3 in row 11, antibody #4 in row 12, antibody #5 in row 13, antibody #6 in row 14, antibody #7 in row 15, antibody #8 in row 16, column A of Table 9, and / or a light chain variable sequence that comprises a framework sequence that at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to the framework sequence of a VL of antibody #1 in row 9; Docket No. A1361.70020WO00 1410150.1antibody #2 in row 10, antibody #3 in row 11, antibody #4 in row 12, antibody #5 in row 13, antibody #6 in row 14, antibody #7 in row 15, antibody #8 in row 16, column B of Table 9. [000132] In some embodiments, an anti-WT1 / HLA-A2 antibody of the present disclosure comprises a HC CDR1, HC CDR2 and HC CDR3 of a heavy chain variable domain having the amino acid sequence of SEQ ID NO: 7. Alternatively or in addition, the anti-WT1 / HLA- A2 antibody of the present disclosure comprises a LC CDR1, LC CDR2 and LC CDR3 of a light chain variable domain having the amino acid sequence of SEQ ID NO: 8. In some embodiments, according to the Kabat definition system, an anti-WT1 / HLA-A2 antibody of the present disclosure comprises a HC CDR1 having the amino acid sequence of X1X2GYYWX3(SEQ ID NO: 59), wherein X1is S, R, or absent; X2is S, G, or absent; and X3is S or G. In some embodiments, an anti-WT1 / HLA-A2 antibody of the present disclosure comprises a HC CDR1 having the amino acid sequence X1X2X3X4X5X6X7, wherein X1 is S, R, or absent, X2 is S, G, or absent, X3 is G or D, X4 is Y or S, X5 is Y or A, X6 is W or M, and X7is G, S, or H. In some embodiments, according to the Kabat definition system, an anti- WT1 / HLA-A2 antibody of the present disclosure comprises a HC CDR2 having an amino acid sequence of X4X5YX6SGX7TX8YNPSLKS (SEQ ID NO: 60), wherein X4 is S or E; X5 is I or F; X6is Y, H, or F; X7is S, T, or N; and X8is Y or N. In some embodiments, an anti- WT1 / HLA-A2 antibody of the present disclosure comprises a HC CDR2 having the amino acid sequence X1X2X3X4X5X6X7X8X9YX11X12SX14X15KX17, wherein X1 is Y, G, or absent, X2is S, E, or I, X3is I, F, or S, X4is Y, S, or W, X5is Y, H, F, or N, X6is S or G, X7is G or S, X8is S, T, or N, X9is Y, N, or G, X11is N or A, X12is P or D, X14is S or L, X15is L or V; and X17 is S or G. In some embodiments, according to the Kabat definition system, an anti- WT1 / HLA-A2 antibody of the present disclosure comprises a HC CDR3 of having the amino acid sequence of SEQ ID NO: 3. In some embodiments, an anti-WT1 / HLA-A2 antibody of the present disclosure comprises a HC CDR3 having the amino acid sequence X1X2X3X4X5WX7X8X9X10X11X12, wherein X1 is D or absent, X2 is H, P, or N, X3 is E, I, or F, X4is P, Q, or S; X5is Y, L, or E; X7is Y, F, or W; X8is F, D, or G; X9is D, Y, or T, X10is L, F, or absent; X11 is D or absent; and X12 is H, Y, or absent. [000133] Alternatively or in addition, according to the Kabat definition system, an anti- WT1 / HLA-A2 antibody of the present disclosure comprises a LC CDR1 having the amino acid sequence of RASQDISNYLX9(SEQ ID NO: 61), wherein X9is A or T In some embodiments, an anti-WT1 / HLA-A2 antibody of the present disclosure comprises an amino acid sequence of RASQX5ISX8X9LX11 (SEQ ID NO: 105), wherein X5 is D or G, X8 is N or Docket No. A1361.70020WO00 1410150.1S, X9is Y or W, and X11is A or T. In some embodiments, according to the Kabat definition system, an anti-WT1 / HLA-A2 antibody of the present disclosure comprises a LC CDR2 having the amino acid sequence of AASX10LX11S (SEQ ID NO: 62), wherein X10 is S or T, and X11is Q or E. In some embodiments, an anti-WT1 HLA-A2 antibody of the present disclosure comprises a LC CDR2 having the amino acid sequence of AASX4X5X6S (SEQ ID NO: 106), wherein X4 is S or T, X5 is L or S, and X6 is Q or E. In some embodiments, according to the Kabat definition system, an anti-WT1 / HLA-A2 antibody of the present disclosure comprises a LC CDR3 having the amino acid sequence of X12X13X14X15X16X17PX18T, wherein X12 is L or Q, X13 is Q or H, X14 is H or Y, X15 is N or R, X16is S, N, or T, X17is Y or L, and X18is R or L. In some embodiments, an anti- WT1 / HLA-A2 antibody of the present disclosure comprises a LC CDR3 having the amino acid sequence of X1X2X3X4X5X6PX8T, wherein X1 is L or Q; X2 is Q or H; X3 is H, Y, or A; X4 is N or R; X5 is S, N, or T; X6 Y, L, or F; and X8 is R, L, or F. [000134] In some embodiments, according to the Kabat definition system, an anti- WT1 / HLA-A2 antibody of the present disclosure comprises a HC CDR1 comprising the amino acid sequence X1X2GYYWX3 (SEQ ID NO: 59), wherein X1 is S, T, N, Q, R, K, or absent; X2is S, T, N, Q, G, or absent; and X3is S, T, N, Q, or G. In some embodiments, according to the Kabat definition system, an anti-WT1 / HLA-A2 antibody of the present disclosure comprises a HC CDR2 comprising the amino acid sequence X4X5YX6SGX7TX8YNPSLKS (SEQ ID NO: 60), wherein X4is S, T, N, Q, E, or D; X5is I, V, L, A, Y, W, or F; X6is Y, W, H, or F; X7is S, T, Q, or N; and X8is Y, W, F, S, T, Q, or N. In some embodiments, according to the Kabat definition system, an anti-WT1 / HLA-A2 antibody of the present disclosure comprises a HC CDR3 comprising the amino acid sequence HEPYWYFDL (SEQ ID NO: 3). In some embodiments, according to the Kabat definition system, an anti-WT1 / HLA-A2 antibody of the present disclosure comprises a light chain complementarity determining region 1 (LC CDR1) comprising the amino acid sequence RASQDISNYLX9(SEQ ID NO: 61), wherein X9is A, I, V, L, S, N, Q, or T. In some embodiments, according to the Kabat definition system, an anti-WT1 / HLA-A2 antibody of the present disclosure comprises a LC CDR2 comprising the amino acid sequence AASX10LX11S (SEQ ID NO: 62), wherein X10is S, T, N, or Q; and X11is S, T, N, Q, D, or E. In some embodiments, according to the Kabat definition system, an anti- WT1 / HLA-A2 antibody of the present disclosure comprises a LC CDR3 comprising the amino acid sequence X12X13X14X15X16X17PX18T, wherein X12 is A, I, V, L, S, N, T, or Q; X13 Docket No. A1361.70020WO00 1410150.1is S, N, T, Q or H; X14is H, F, W or Y; X15is S, T, Q, N, K, or R; X16is S, Q, N, or T; X17is Y, F, W, A, V, I or L; and X18 is K, R, A, V, I, or L. [000135] An anti-WT1 / HLA-A2 antibody described herein can be in any antibody form, including, but not limited to, intact (i.e., full-length) antibodies, antigen-binding fragments thereof (such as Fab, F(ab'), F(ab')2, Fv), single chain antibodies, bi-specific antibodies, or nanobodies. In some embodiments, the anti-WT1 / HLA-A2 antibody described herein is a scFv. In some embodiments, the anti-WT1 / HLA-A2 antibody described herein is a scFv-Fab (e.g., scFv fused to a portion of a constant region). Provided herein, in some embodiments, is a bispecific antibody. In some embodiments, the first antigen binding site of the bispecific antibody specifically binds WT1 / HLA-A2. In some embodiments, the second antigen binding site specifically binds a T cell antigen. In some antibodies, the T cell antigen is a CD3 complex or a portion thereof. [000136] In some embodiments, conservative mutations can be introduced into antibody sequences (e.g., CDRs or framework sequences) at positions where the residues are not likely to be involved in interacting with a target antigen (e.g., WT1 / HLA-A2), for example, as determined based on a crystal structure. In some embodiments, one, two or more mutations (e.g., amino acid substitutions) are introduced into the Fc region of an anti-WT1 antibody described herein (e.g., in a CH2 domain (residues 231-340 of human IgG1) and / or CH3 domain (residues 341-447 of human IgG1) and / or the hinge region, with numbering according to the Kabat numbering system (e.g., the EU index in Kabat)) to alter one or more functional properties of the antibody, such as serum half-life, complement fixation, Fc receptor binding and / or antigen-dependent cellular cytotoxicity. [000137] In some embodiments, one, two or more mutations (e.g., amino acid substitutions) are introduced into the hinge region of the Fc region (CH1 domain) such that the number of cysteine residues in the hinge region are altered (e.g., increased or decreased) as described in, e.g., U.S. Pat. No. 5,677,425. The number of cysteine residues in the hinge region of the CH1 domain can be altered to, e.g., facilitate assembly of the light and heavy chains, or to alter (e.g., increase or decrease) the stability of an antibody or to facilitate linker conjugation. [000138] In some embodiments, one, two or more mutations (e.g., amino acid substitutions) are introduced into the Fc region of an antibody described herein (e.g., in a CH2 domain (residues 231-340 of human IgG1) and / or CH3 domain (residues 341-447 of human IgG1) and / or the hinge region, with numbering according to the Kabat numbering system (e.g., the EU index in Kabat)) to increase or decrease the affinity of an antibody for an Fc receptor Docket No. A1361.70020WO00 1410150.1(e.g., an activated Fc receptor) on the surface of an effector cell. Mutations in the Fc region of an antibody that decrease or increase the affinity of an antibody for an Fc receptor and techniques for introducing such mutations into the Fc receptor or fragment thereof are known to one of skill in the art. Examples of mutations in the Fc receptor of an antibody that can be made to alter the affinity of the antibody for an Fc receptor are described in, e.g., Smith P et al., (2012) PNAS 109: 6181-6186, U.S. Pat. No. 6,737,056, and International Publication Nos. WO 02 / 060919; WO 98 / 23289; and WO 97 / 34631, which are incorporated herein by reference. [000139] In some embodiments, one, two or more amino acid mutations (i.e., substitutions, insertions or deletions) are introduced into an IgG constant domain, or FcRn-binding fragment thereof (preferably an Fc or hinge-Fc domain fragment) to alter (e.g., decrease or increase) half-life of an antibody in vivo. See, e.g., International Publication Nos. WO 02 / 060919; WO 98 / 23289; and WO 97 / 34631; and U.S. Pat. Nos. 5,869,046, 6,121,022, 6,277,375 and 6,165,745 for examples of mutations that will alter (e.g., decrease or increase) the half-life of an antibody in vivo. [000140] In some embodiments, one, two or more amino acid mutations (i.e., substitutions, insertions, or deletions) are introduced into an IgG constant domain, or FcRn-binding fragment thereof (preferably an Fc or hinge-Fc domain fragment) to decrease the half-life of the anti-WT1 / HLA-A2 antibody in vivo. [000141] In some embodiments, one, two or more amino acid mutations (i.e., substitutions, insertions or deletions) are introduced into an IgG constant domain, or FcRn-binding fragment thereof (preferably an Fc or hinge-Fc domain fragment) to increase the half-life of an antibody in vivo. In some embodiments, antibodies can have one or more amino acid mutations (e.g., substitutions) in the second constant (CH2) domain (residues 231-340 of human IgG1) and / or the third constant (CH3) domain (residues 341-447 of human IgG1), with numbering according to the EU index in Kabat (Kabat E A et al., (1991) supra). In some embodiments, the constant region of the IgG1 of an antibody described herein comprises a methionine (M) to tyrosine (Y) substitution in position 252, a serine (S) to threonine (T) substitution in position 254, and a threonine (T) to glutamic acid (E) substitution in position 256, numbered according to the EU index as in Kabat. See U.S. Pat. No. 7,658,921, which is incorporated herein by reference. This type of mutant IgG, referred to as "YTE mutant" has been shown to display fourfold increased half-life as compared to wild-type versions of the same antibody (see Dall'Acqua W F et al., (2006) J Biol Chem 281: 23514-24). In some Docket No. A1361.70020WO00 1410150.1embodiments, an antibody comprises an IgG constant domain comprising one, two, three or more amino acid substitutions of amino acid residues at positions 251-257, 285-290, 308- 314, 385-389, and 428-436, numbered according to the EU index as in Kabat. [000142] In some embodiments, one, two or more amino acid substitutions are introduced into an IgG constant domain Fc region to alter the effector function(s) of the anti-WT1 / HLA- A2 antibody. The effector ligand to which affinity is altered can be, for example, an Fc receptor or the C1 component of complement. This approach is described in further detail in U.S. Pat. Nos. 5,624,821 and 5,648,260 (e.g., a L234A and L235A mutation). In some embodiments, the deletion or inactivation (through point mutations or other means) of a constant region domain can reduce Fc receptor binding of the circulating antibody thereby increasing tumor localization. See, e.g., U.S. Pat. Nos. 5,585,097 and 8,591,886 for a description of mutations that delete or inactivate the constant domain and thereby increase tumor localization. In some embodiments, one or more amino acid substitutions may be introduced into the Fc region of an antibody described herein to remove potential glycosylation sites on Fc region, which may reduce Fc receptor binding (see, e.g., Shields R L et al., (2001) J Biol Chem 276: 6591-604). [000143] In some embodiments, one or more amino in the constant region of an anti- WT1 / HLA-A2 antibody described herein can be replaced with a different amino acid residue such that the antibody has altered Clq binding and / or reduced or abolished complement dependent cytotoxicity (CDC). This approach is described in further detail in U.S. Pat. No. 6,194,551 (Idusogie et al). In some embodiments, one or more amino acid residues in the N- terminal region of the CH2 domain of an antibody described herein are altered to thereby alter the ability of the antibody to fix complement. This approach is described further in International Publication No. WO 94 / 29351. In some embodiments, the Fc region of an antibody described herein is modified to increase the ability of the antibody to mediate antibody dependent cellular cytotoxicity (ADCC) and / or to increase the affinity of the antibody for an Fcγ receptor. This approach is described further in International Publication No. WO 00 / 42072. [000144] In some embodiments, the heavy and / or light chain variable domain(s) sequence(s) of the antibodies provided herein can be used to generate, for example, CDR-grafted, chimeric, humanized, or composite human antibodies or antigen-binding fragments, as described elsewhere herein. As understood by one of ordinary skill in the art, any variant, CDR-grafted, chimeric, humanized, or composite antibodies derived from any of the Docket No. A1361.70020WO00 1410150.1antibodies provided herein may be useful in the compositions and methods described herein and will maintain the ability to specifically bind WT1 / HLA-A2, such that the variant, CDR- grafted, chimeric, humanized, or composite antibody has at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95% or more binding to WT1 / HLA-A2 relative to the original antibody from which it is derived. [000145] In some embodiments, antibodies provided herein comprise mutations that confer desirable properties to the antibodies. For example, to avoid potential complications due to Fab-arm exchange, which is known to occur with native IgG4 mAbs, the antibodies provided herein may comprise a stabilizing ‘Adair’ mutation (Angal S., et al., “A single amino acid substitution abolishes the heterogeneity of chimeric mouse / human (IgG4) antibody,” Mol Immunol 30, 105-108; 1993), where serine 228 (EU numbering; residue 241 Kabat numbering) is converted to proline resulting in an IgG1-like hinge sequence. Accordingly, any of the antibodies may include a stabilizing ‘Adair’ mutation. [000146] In some embodiments, an antibody is modified, e.g., modified via glycosylation, phosphorylation, sumoylation, and / or methylation. In some embodiments, an antibody is a glycosylated antibody, which is conjugated to one or more sugar or carbohydrate molecules. In some embodiments, the one or more sugar or carbohydrate molecule are conjugated to an antibody via N-glycosylation, O-glycosylation, C-glycosylation, glypiation (GPI anchor attachment), and / or phosphoglycosylation. In some embodiments, the one or more sugar or carbohydrate molecules are monosaccharides, disaccharides, oligosaccharides, or glycans. In some embodiments, the one or more sugar or carbohydrate molecule is a branched oligosaccharide or a branched glycan. In some embodiments, the one or more sugar or carbohydrate molecule includes a mannose unit, a glucose unit, an N-acetylglucosamine unit, an N-acetylgalactosamine unit, a galactose unit, a fucose unit, or a phospholipid unit. In some embodiments, there are about 1-10, about 1-5, about 5-10, about 1-4, about 1-3, or about 2 sugar molecules. In some embodiments, a glycosylated antibody is fully or partially glycosylated. In some embodiments, an antibody is glycosylated by chemical reactions or by enzymatic means. In some embodiments, an antibody is glycosylated in vitro or inside a cell, which may optionally be deficient in an enzyme in the N- or O- glycosylation pathway, e.g. a glycosyltransferase. In some embodiments, an antibody is functionalized with sugar or carbohydrate molecules as described in International Patent Application Publication WO2014065661, published on May 1, 2014, entitled, “Modified antibody, antibody- conjugate and process for the preparation thereof”. Docket No. A1361.70020WO00 1410150.1[000147] In some embodiments, any one of an anti-WT1 / HLA-A2 antibody described herein may comprise a signal peptide in the heavy and / or light chain sequence (e.g., a N-terminal signal peptide). In some embodiments, the anti-WT1 / HLA-A2 antibody described herein comprises any one of the VH and VL sequences, any one of the IgG heavy chain and light chain sequences, or any one of the F(ab’) heavy chain and light chain sequences described herein, and further comprises a signal peptide (e.g., a N-terminal signal peptide). [000148] In some embodiments, any one of the antibodies described herein is a multispecific antibody that specifically binds WT1 / HLA-A2 and one or more additional target antigens. In some embodiments, an antibody is a bispecific antibody that specifically binds to WT1 / HLA- A2 and one additional target antigen. In some embodiments, the multispecific antibody or bispecific antibody can be obtained by known technology in the art. In some embodiments, the one or more additional target includes are not limited to CD3, CD4, CD8, CD20, CD19, CD21, CD23, CD46, CD80, HLA-DR, CD74, CD22, CD14, CD15, CD16, CD123, TCR gamma / delta, NKp46, or KIR. [000149] In some embodiments, the antibodies described herein are conjugated directly or indirectly to one or more molecular payloads or labels. For example, in some embodiments, antibodies described herein are conjugated to molecular payload, e.g., a molecular payload providing a therapeutic benefit for a subject, e.g., an antibody-drug conjugate (ADC). In some embodiments, a molecular payload may be a small molecule, protein, nucleic acid, oligonucleotide, or any molecular entity capable of modulating the activity or function of a gene, protein, and / or nucleic acid, e.g., in a cell. In some embodiments, the molecular payload is a cytotoxic agent or a chemotherapeutic agent. In some embodiments, antibodies described herein are conjugated directly or indirectly to a detectable label, e.g., for diagnostic purposes. [000150] In some embodiments, the present disclosure also provides fusion proteins comprising an anti-WT1 / HLA-A2 antibody described herein fused directly or indirectly (e.g., via a linker) to one or more polypeptide or protein. (b) Chimeric Antigen Receptors [000151] In some aspects, the present disclosure also contemplates engineering any of the anti-WT1 / HLA-A2 antibody to be an extracellular ligand-binding domain of a CAR expressed by genetically modified immune cells (e.g., T cells, NK cells, or NKT cells) described herein. Aspects of the present disclosure also provide chimeric antigen receptors Docket No. A1361.70020WO00 1410150.1(CARs) comprising an extracellular ligand-binding domain. In some embodiments, the ligand-binding domain binds to a cell surface marker on a target cell (e.g., a cancer cell). In some embodiments, the ligand-binding domain binds to a cell surface marker on a target cell in a particular disease state (e.g., WT1 / HLA-A2 on tumor cells in cancer). Generally, a CAR (e.g., anti-WT1 / HLA-A2 CAR) of the present disclosure comprises at least an extracellular domain and an intracellular domain. In some embodiments, the extracellular domain of an anti-WT1 / HLA-A2 CAR comprises a target-specific binding element (e.g., an antibody that specifically binds to WT1 / HLA-A2 (e.g., human WT1 / HLA-A2)) otherwise referred to herein as a ligand-binding domain (also referred to herein as an antigen-binding domain). In some embodiments, the extracellular ligand-binding domain of an anti-WT1 / HLA-A2 CAR is an antigen-binding domain or a portion thereof. In some embodiments, the extracellular ligand-binding domain of an anti-WT1 / HLA-A2 CAR is a Fab. In some embodiments, the extracellular ligand-binding domain of an anti-WT1 / HLA-A2 CAR is a scFv. In some embodiments, an extracellular ligand-binding domain of a CAR described herein comprises an anti-WT1 antibody or antigen binding fragments thereof as described in Table 1 (e.g., anti- WT1 / HLA-A2 antibody). [000152] In some embodiments, an anti-WT1 / HLA-A2 CAR of the present disclosure comprises a HC CDR1, HC CDR2 and HC CDR3 of a heavy chain variable domain having the amino acid sequence of antibody #1 in row 9; antibody #2 in row 10, antibody #3 in row 11, antibody #4 in row 12, antibody #5 in row 13, antibody #6 in row 14, antibody #7 in row 15, or antibody #8 in row 16, column A of Table 9. Alternatively or in addition, an anti- WT1 / HLA-A2 CAR of the present disclosure comprises a LC CDR1, LC CDR2 and LC CDR3 of antibody #1 in row 9; antibody #2 in row 10, antibody #3 in row 11, antibody #4 in row 12, antibody #5 in row 13, antibody #6 in row 14, antibody #7 in row 15, antibody #8 in row 16, column B of Table 9. [000153] In some embodiments, an anti-WT1 / HLA-A2 CAR of the present disclosure comprises a HC CDR1, a HC CDR2, a HC CDR3, a LC CDR1, a LC CDR2, and a LC CDR3 having the amino acid sequences of antibody #1 in row 1, antibody #2 in row 2, antibody #3 in row 3, antibody #4 in row 4, antibody #5 in row 5, antibody #6 in row 6, antibody #7 in row 7, or antibody #8 in row 8, columns A and B of Table 8. [000154] In some embodiments, an anti-WT1 / HLA-A2 CAR of the present disclosure comprises a HC CDR1, a HC CDR2, and a HC CDR3, which collectively contains no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation) as Docket No. A1361.70020WO00 1410150.1compared with the HC CDR1, the HC CDR2, and the HC CDR3 amino acid sequences of antibody #1 in row 1, antibody #2 in row 2, antibody #3 in row 3, antibody #4 in row 4, antibody #5 in row 5, antibody #6 in row 6, antibody #7 in row 7, or antibody #8 in row 8, column A of Table 8. “Collectively,” as used anywhere in the present disclosure, means that the total number of amino acid variations in all of the three heavy chain CDRs is within the defined range. Alternatively or in addition, the anti-WT1 / HLA-A2 CAR of the present disclosure comprises a LC CDR1, a LC CDR2, and a LC CDR3, which collectively contains no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2 or 1 amino acid variation) as compared with the LC CDR1, the LC CDR2, and the LC CDR3 amino acid sequences of antibody #1 in row 1, antibody #2 in row 2, antibody #3 in row 3, antibody #4 in row 4, antibody #5 in row 5, antibody #6 in row 6, antibody #7 in row 7, or antibody #8 in row 8, column B of Table 8. [000155] In some embodiments, an anti-WT1 / HLA-A2 CAR of the present disclosure comprises a HC CDR1, a HC CDR2, and a HC CDR3 that collectively are at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to the HC CDR1, the HC CDR2, and the HC CDR3 amino acid sequences of antibody #1 in row 1, antibody #2 in row 2, antibody #3 in row 3, antibody #4 in row 4, antibody #5 in row 5, antibody #6 in row 6, antibody #7 in row 7, or antibody #8 in row 8, column A of Table 8. Alternatively or in addition, the anti-WT1 / HLA-A2 CAR of the present disclosure comprises a LC CDR1, a LC CDR2, and a LC CDR3 that collectively are at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to the LC CDR1, the LC CDR2, and the LC CDR3 amino acid sequences of antibody #1 in row 1, antibody #2 in row 2, antibody #3 in row 3, antibody #4 in row 4, antibody #5 in row 5, antibody #6 in row 6, antibody #7 in row 7, or antibody #8 in row 8, column B of Table 8. [000156] In some embodiments, an anti-WT-1 / HLA-A2 CAR of the present disclosure comprises: a HC CDR1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation), a HC CDR2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation), and / or a HC CDR3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) as compared with the HC CDR1, the HC CDR2, and the HC CDR3 amino acid sequences of antibody #1 in row 1, antibody #2 in row 2, antibody #3 in row 3, antibody #4 in row 4, antibody #5 in row 5, Docket No. A1361.70020WO00 1410150.1antibody #6 in row 6, antibody #7 in row 7, or antibody #8 in row 8, column A of Table 8. Alternatively or in addition, the anti-WT1 / HLA-A2 CAR of the present disclosure comprises: a LC CDR1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) a LC CDR2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation), and / or a LC CDR3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) as compared with the LC CDR1, the LC CDR2, and the LC CDR3 amino acid sequences of antibody #1 in row 1, antibody #2 in row 2, antibody #3 in row 3, antibody #4 in row 4, antibody #5 in row 5, antibody #6 in row 6, antibody #7 in row 7, or antibody #8 in row 8, column B of Table 8. [000157] In some embodiments, an anti-WT1 / HLA-A2 CAR of the present disclosure comprises: a HC CDR1 that is at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to the HC CDR1, a HC CDR2 that is at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to the HC CDR2, and / or a HC CDR3 that is at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to the HC CDR3 amino acid sequence of antibody #1 in row 1, antibody #2 in row 2, antibody #3 in row 3, antibody #4 in row 4, antibody #5 in row 5, antibody #6 in row 6, antibody #7 in row 7, or antibody #8 in row 8, column A of Table 8. Alternatively or in addition, the anti-WT1 / HLA-A2 CAR of the present disclosure comprises: a LC CDR1 that is at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to the LC CDR1; a LC CDR2 that is at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to the LC CDR2; and / or a LC CDR3 that is at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to the LC CDR3 amino acid sequence of antibody #1 in row 1, antibody #2 in row 2, antibody #3 in row 3, antibody #4 in row 4, antibody #5 in row 5, antibody #6 in row 6, antibody #7 in row 7, or antibody #8 in row 8, column B of Table 8. Docket No. A1361.70020WO00 1410150.1[000158] In some embodiments, an anti-WT1 / HLA-A2 CAR of the present disclosure comprises a VH comprising the amino acid sequence of antibody #1 in row 9; antibody #2 in row 10, antibody #3 in row 11, antibody #4 in row 12, antibody #5 in row 1, antibody #6 in row 14, antibody #7 in row 15, antibody #8 in row 16, column A of Table 9. Alternatively or in addition, the anti-WT1 / HLA-A2 CAR of the present disclosure comprises a VL comprising the amino acid sequence of antibody #1 in row 9; antibody #2 in row 10, antibody #3 in row 11, antibody #4 in row 12, antibody #5 in row 13, antibody #6 in row 14, antibody #7 in row 15, antibody #8 in row 16, column B of Table 9. [000159] In some embodiments, the anti-WT1 / HLA-A2 CAR of the present disclosure comprises a VH containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) as compared with the VH amino acid sequence of antibody #1 in row 9; antibody #2 in row 10, antibody #3 in row 11, antibody #4 in row 12, antibody #5 in row 13, antibody #6 in row 14, antibody #7 in row 15, antibody #8 in row 16, column A of Table 9. Alternatively or in addition, the anti-WT1 / HLA-A2 CAR of the present disclosure comprises a VL containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) as compared with the VL amino acid sequence of antibody #1 in row 9; antibody #2 in row 10, antibody #3 in row 11, antibody #4 in row 12, antibody #5 in row 13, antibody #6 in row 14, antibody #7 in row 15, antibody #8 in row 16, column B of Table 9. In some embodiments, the number of amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) may occur within a VH amino acid sequence of antibody #1 in row 9; antibody #2 in row 10, antibody #3 in row 11, antibody #4 in row 12, antibody #5 in row 13, antibody #6 in row 14, antibody #7 in row 15, antibody #8 in row 16, column A of Table 9 and / or a VL amino acid sequence of antibody #1 in row 9; antibody #2 in row 10, antibody #3 in row 11, antibody #4 in row 12, antibody #5 in row 13, antibody #6 in row 14, antibody #7 in row 15, antibody #8 in row 16, column B of Table 9 excluding any of the CDR sequences therein. [000160] In some embodiments, an anti-WT1 / HLA-A2 CAR provided herein comprise a heavy chain variable sequence that comprises a framework sequence that that contains no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation to the framework sequence of a VH amino acid sequence of antibody #1 in row 9; antibody #2 in row 10, antibody #3 in row 11, antibody #4 in row 12, antibody #5 in row 13, antibody #6 in row 14, antibody #7 in row 15, antibody #8 in row 16, column A of Table 9, Docket No. A1361.70020WO00 1410150.1and / or a light chain variable sequence that comprises a framework sequence that that contains no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation to the framework sequence of a VL amino acid sequence of antibody #1 in row 9; antibody #2 in row 10, antibody #3 in row 11, antibody #4 in row 12, antibody #5 in row 13, antibody #6 in row 14, antibody #7 in row 15, antibody #8 in row 16, column B of Table 9. [000161] In some embodiments, the anti-WT1 / HLA-A2 CAR of the present disclosure comprises a VH comprising an amino acid sequence that is at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to the VH amino acid sequence of antibody #1 in row 9; antibody #2 in row 10, antibody #3 in row 11, antibody #4 in row 12, antibody #5 in row 13, antibody #6 in row 14, antibody #7 in row 15, antibody #8 in row 16, column A of Table 9. Alternatively or in addition, the anti-WT1 / HLA-A2 CAR of the present disclosure comprises a VL comprising an amino acid sequence that is at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to the VL antibody #1 in row 9; antibody #2 in row 10, antibody #3 in row 11, antibody #4 in row 12, antibody #5 in row 13, antibody #6 in row 14, antibody #7 in row 15, antibody #8 in row 16, column B of Table 9. [000162] In some embodiments, the degree of sequence variation (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) may occur within a VH of antibody #1 in row 9; antibody #2 in row 10, antibody #3 in row 11, antibody #4 in row 12, antibody #5 in row 13, antibody #6 in row 14, antibody #7 in row 15, antibody #8 in row 16, column A of Table 9, and / or a VL of antibody #1 in row 9; antibody #2 in row 10, antibody #3 in row 11, antibody #4 in row 12, antibody #5 in row 13, antibody #6 in row 14, antibody #7 in row 15, antibody #8 in row 16, column B of Table 9 excluding any of the CDR sequences therein. [000163] In some embodiments, an anti-WT1 / HLA-A2 CAR provided herein comprise a heavy chain variable sequence that is at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to the framework sequence of a VH of antibody #1 in row 9; antibody #2 in row 10, antibody #3 in row 11, antibody #4 in row 12, antibody #5 in row 13, antibody #6 in row 14, antibody #7 in row 15, antibody #8 in row 16, column A of Table 9, and / or a light chain variable sequence that comprises a framework Docket No. A1361.70020WO00 1410150.1sequence that at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to the framework sequence of a VL of antibody #1 in row 9; antibody #2 in row 10, antibody #3 in row 11, antibody #4 in row 12, antibody #5 in row 13, antibody #6 in row 14, antibody #7 in row 15, antibody #8 in row 16, column B of Table 9. [000164] In some embodiments, an anti-WT1 / HLA-A2 CAR comprises a HC CDR1, a HC CDR2 and a HC CDR3 of a heavy chain variable domain (VH) having the amino acid sequence of SEQ ID NO: 7. Alternatively or in addition, an anti-WT1 CAR comprises a LC CDR1, a LC CDR2 and a LC CDR3 of a light chain variable domain (VL) having the amino acid sequence of SEQ ID NO: 8. [000165] In some embodiments, the anti-WT1 / HLA-A2 CAR of the present disclosure comprises a HC CDR1, HC CDR2 and HC CDR3 of a heavy chain variable domain having the amino acid sequence of SEQ ID NO: 7. Alternatively or in addition, the anti-WT1 / HLA- A2 antibody of the present disclosure comprises a LC CDR1, LC CDR2 and LC CDR3 of a light chain variable domain having the amino acid sequence of SEQ ID NO: 8. In some embodiments, the anti-WT1 / HLA-A2 CAR of the present disclosure comprises a HC CDR1 having the amino acid sequence of X1X2GYYWX3(SEQ ID NO: 59), wherein X1is S, R, or absent; X2 is S, G, or absent; and X3 is S or G, and / or a HC CDR2 having an amino acid sequence of X4X5YX6SGX7TX8YNPSLKS (SEQ ID NO: 60), wherein X4 is S or E; X5 is I or F; X6is Y, H, or F; X7is S, T, or N; and X8is Y or N, and / or a HC CDR3 having an amino acid sequence of SEQ ID NO: 3. Alternatively or in addition, according to the Kabat definition system, the anti-WT1 / HLA-A2 CAR of the present disclosure comprises a LC CDR1 having the amino acid sequence of RASQDISNYLX9 (SEQ ID NO: 61), wherein X9 is A or T; and / or a LC CDR2 having the amino acid sequence of AASX10LX11S (SEQ ID NO: 62), wherein X10 is S or T, and X11 is Q or E; and / or a LC CDR3 having the amino acid sequence of X12X13X14X15X16X17PX18T, wherein X12 is L or Q, X13 is Q or H, X14 is H or Y, X15is N or R, X16is S, N, or T, X17is Y or L, and X18is R or L. [000166] In some embodiments, the anti-WT1 / HLA-A2 CAR of the present disclosure comprises a HC CDR1 having the amino acid sequence X1X2X3X4X5X6X7, wherein X1 is S, R, or absent, X2is S, G, or absent, X3is G or D, X4is Y or S, X5is Y or A, X6is W or M, and X7is G, S, or H; a HC CDR2 having the amino acid sequence X1X2X3X4X5X6X7X8X9YX11X12SX14X15KX17, wherein X1 is Y, G, or absent, X2 is S, E, or I, X3 is I, F, or S, X4 is Y, S, or W, X5 is Y, H, F, or N, X6 is S or G, X7 is G or S, X8 is S, T, or Docket No. A1361.70020WO00 1410150.1N, X9is Y, N, or G, X11is N or A, X12is P or D, X14is S or L, X15is L or V; and X17is S or G; and a HC CDR3 having the amino acid sequence X1X2X3X4X5WX7X8X9X10X11X12, wherein X1 is D or absent, X2 is H, P, or N, X3 is E, I, or F, X4 is P, Q, or S; X5 is Y, L, or E; X7is Y, F, or W; X8is F, D, or G; X9is D, Y, or T, X10is L, F, or absent; X11is D or absent; and X12 is H, Y, or absent. In some embodiments, the anti-WT1 / HLA-A2 CAR comprises a HC CDR3 having the amino acid sequence of SEQ ID NO: 3. [000167] In some embodiments, an anti-WT1 / HLA-A2 CAR comprises an extracellular ligand-binding domain that comprises a single-chain variable fragment (scFv). In some embodiments, the VH and the VL of an anti-WT1 / HLA-A2 CAR (e.g., an anti-WT1 / HLA- A2 scFv) are joined together by a linker. In some embodiments, a linker may have a length of about 2 to 10 amino acids, 5 to 20 amino acids, 10 to 30 amino acids, 20-50 amino acids, 40 to 60 amino acids, 60 to 80 amino acids, or more than 80 amino acids. In some embodiments, a linker may include, without limitation, any of those encompassed by U.S. Patent Nos. 8,445,251 and 9,434,931. [000168] In some embodiments, an anti-WT1 / HLA-A2 CAR comprises an extracellular ligand-binding domain that comprises a scFv comprising a VH and a VL, and the C-terminus of the VH is joined with the N terminus of the VL via a linker. In some embodiments, an anti-WT1 / HLA-A2 CAR comprises an extracellular ligand-binding domain that comprises scFv comprising a VH and a VL, and the C-terminus of the VL is joined with the N terminus of the VH via a linker. In some embodiments, an anti-WT1 / HLA-A2 CAR of the present disclosure further comprises a hinge region. Any suitable known hinge region can be used in the anti-WT1 / HLA-A2 CAR described herein, e.g., hinge regions derived from CD4, CD8, CD28, CD3, IgG1, IgG4, IgD, IgA, or IgM, a hybrid or variant therefore (see, e.g., Jayaraman et al., CAR-T design: Elements and their synergistic function, eBioMedicine, VOLUME 58, 102931, AUGUST 2020); Guedan et al., Engineering and Design of Chimeric Antigen Receptors, Mol Ther Methods Clin Dev. 2019 Mar 15; 12: 145–156). [000169] In some embodiments, an anti-WT1 / HLA-A2 CAR of the present disclosure further comprises a transmembrane domain, which links the extracellular ligand-binding domain with the intracellular signaling and co-stimulatory domains. With respect to the transmembrane domain, the CAR can be designed to comprise a transmembrane domain that is fused to the extracellular domain (e.g., the antigen binding domain) of the CAR directly or via the hinge region. Any transmembrane domain is contemplated for use herein as long as Docket No. A1361.70020WO00 1410150.1the domain is capable of anchoring a CAR comprising the domain to a cell membrane. In some embodiments, the transmembrane domain that naturally is associated with one of the domains in the CAR is used. In some instances, the transmembrane domain can be selected or modified by amino acid substitution to avoid binding of such domains to the transmembrane domains of the same or different surface membrane proteins to minimize interactions with other members of the receptor complex. One skilled in the art would appreciate that the full transmembrane domain, or portion thereof, is implemented with the cytoplasmic domain, or a portion thereof. The transmembrane domain may be derived either from a natural or from a synthetic source. Where the source is natural, the domain may be derived from any membrane-bound or transmembrane protein. In some embodiments, the transmembrane domain may be synthetic, in which case it will comprise predominantly hydrophobic residues such as leucine and valine. Preferably a triplet of phenylalanine, tryptophan and valine will be found at each end of a synthetic transmembrane domain. Optionally, a short oligo- or polypeptide linker, preferably between 2 and 10 amino acids in length may form the linkage between the transmembrane domain and the cytoplasmic signaling domain of the CAR. A glycine-serine doublet provides a particularly suitable linker. In some embodiments, the transmembrane domain can be any suitable transmembrane domain known in the art, e.g., transmembrane domain derived from TCRα, TCRβ, TCRζ, CD3ζ, CD3ε, CD3γ, CD3δ, CD4, CD5, CD8, CD9, CD16, CD22, CD28, CD32, CD33, CD34, CD37, CD45, CD64, CD80, CD86, CD134, CD137, CD154, or inducible T cell costimulator (ICOS). However, any transmembrane domain is contemplated for use herein as long as the domain is capable of anchoring a CAR comprising the extracellular domain to a cell membrane. Transmembrane domains can be identified using any method known in the art or described herein, e.g., by using the UniProt Database. [000170] In some embodiments, an anti-WT1 / HLA-A2 CAR further comprises an intracellular (or cytoplasmic) domain. In some embodiments, the intracellular domain of the CAR is responsible for activation of at least one of the normal effector functions of the immune cell in which the CAR has been placed in. The term “effector function” refers to a specialized function of a cell (e.g., a T cell, a NK cell, or a NKT cell). Effector function of a cell (e.g., a T cell, a NK cell, or a NKT cell), for example, may be cytolytic activity or helper activity including the secretion of cytokines. Thus, the term “intracellular signaling domain” refers to the portion of a protein which transduces the effector function signal and directs the cell to perform a specialized function. While usually the entire intracellular signaling domain Docket No. A1361.70020WO00 1410150.1can be employed, in many cases it is not necessary to use the entire domain. To the extent that a truncated portion of the intracellular signaling domain is used, such truncated portion may be used in place of the intact domain as long as it transduces the effector function signal. The term intracellular signaling domain is thus meant to include any truncated portion of the intracellular signaling domain sufficient to transduce the effector function signal. In certain embodiments, the intracellular (or cytoplasmic) domain of a chimeric antigen receptor as disclosed herein may include, but is not limited to, a 4-1BB intracellular domain, a OX40 intracellular domain, a CD30 intracellular domain, a CD40 intracellular domain, an ICOS intracellular domain, a LFA-1 intracellular domain, a CD2 intracellular domain, a CD3 ζ intracellular domain, a CD3 γ intracellular domain, a CD3 δ intracellular domain, a CD3 ε intracellular domain, and a CD7 intracellular domain. [000171] In some embodiments, the intracellular domain further comprises one or more intracellular co-stimulatory domains, such as those described herein, which transmit a co- stimulatory signal which promotes cell proliferation, cell survival, and / or cytokine secretion after binding of the extracellular domain. In some embodiments, such intracellular co- stimulatory domains include, without limitation, any co-stimulatory domain disclosed herein or those domains known in the art, including but not limited to CD28, ICOS, 4-1BB, OX40, or CD27. [000172] The intracellular signaling domain of a chimeric antigen receptor of the present disclosure is responsible for activation of at least one of the normal effector functions of the cell in which the CAR has been placed and / or activation of proliferative and cell survival pathways. [000173] It is to be understood that a chimeric antigen receptor as disclosed herein can include a domain (e.g., an extracellular domain, a transmembrane domain, an intracellular (cytoplasmic) domain, a co-stimulatory domain, a signaling domain, or any combination thereof) having a sequence as set forth herein, or a variant thereof, or a fragment thereof, of any one or more of the domains disclosed herein (e.g., a variant and / or fragment that retains the function required for the chimeric antigen receptor activity). (c) T cell engaging bispecific antibodies targeting a WT1 / HLA-A2 complex [000174] In some aspects, the present disclosure provides a multispecific (e.g., a bispecific) antibody comprising one or more first antigen binding sites targeting a WT1 / HLA-A2 complex, and one or more second binding sites targeting one or more different epitopes on a Docket No. A1361.70020WO00 1410150.1WT1 / HLA-A2 complex. In some aspects, the present disclosure provides a multispecific (e.g., a bispecific) antibody comprising one or more first antigen binding sites targeting a WT1 / HLA-A2 complex and one or more second antigen binding sites targeting one or more different antigens. [000175] In some embodiments, the present disclosure provides a bispecific antibody comprising a first antigen binding site targeting a WT1 / HLA-A2 complex, and a second binding site. In some embodiments, the present disclosure provides a bispecific antibody comprising a first antigen binding site targeting a WT1 / HLA-A2 complex, and a second antigen binding site that specifically binds a different epitope on a WT1 / HLA-A2 complex. In some embodiments, the present disclosure provides a bispecific antibody comprising a first antigen binding site targeting a WT1 / HLA-A2 complex, and a second antigen binding site that specifically binds a different epitope on a different antigen. In some embodiments, a bispecific antibody described herein comprises a first antigen binding site comprising an antigen binding site of any one of the WT1 / HLA-A2 complex antibodies described in Table 1. In some embodiments, a bispecific antibody described herein comprises a first antigen binding site comprising a HC CDR1, HC CDR2, HC CDR3, LC CDR1, LC CDR2, and / or LC CDR3 of any one of the anti-WT1 / HLA-A2 complex antibodies described in Table 1. In some embodiments, a bispecific antibody described herein comprises a first antigen binding site comprising a VH and / or VL of any one of the anti-WT1 / HLA-A2 complex antibodies described in Table 1. [000176] In some embodiments, a bispecific antibody described herein is a T cell engaging antibody that also targets a WT1 / HLA-A2 complex. In some embodiments, a bispecific antibody described herein comprises a first antigen binding site that specifically binds a WT1 / HLA-A2 complex and a second antigen binding site that specifically binds a T cell antigen (referred to as an anti-WT1 / HLA-A2xT cell bispecific antibody. In some embodiments, an anti-WT1 / HLA-A2xT cell bispecific antibody comprises a second antigen binding site that specifically binds a T cell receptor specifically binds a CD3 complex. In some embodiments, the second antigen binding site specifically binds to CD3ε of a CD3 complex. In some embodiments, the second antigen binding site specifically binds to CD3γ of a CD3 complex. In some embodiments, the second antigen binding site specifically binds to CD3δ of a CD3 complex. In some embodiments, the second antigen binding site specifically binds to a CD3ε / δ heterodimer of a CD3 complex. In some embodiments, the second antigen binding site specifically binds to a CD3ε / γ heterodimer of a CD3 complex. Docket No. A1361.70020WO00 1410150.1Any suitable antigen binding site that specifically binds to CD3 derived from an anti-CD3 antibody can be combined with an antigen binding site that specifically binds to a WT1 / HLA- A2 complex as described herein to form an anti-WT1 / HLA-A2xT cell bispecific antibody of the present disclosure. In some embodiments, an anti-WT1 / HLA-A2xT cell bispecific antibody comprises a second antigen binding site that specifically binds to CD3 that is derived from any one of the anti-CD3 antibodies previously described, e.g., in US10968276, US20060275292, WO1997044362, WO2005118635, WO2007042261, WO2011050262, WO2011078332, WO2012073985, WO2012158818, WO2012098238, WO2012162067, WO2013026835, WO2013026839, WO2013026833, WO2013026831, WO2013065708, WO2014047231, WO2014012085, WO2015095392, WO2015143079, WO2015181098, WO2016116626, WO2016020332, WO2016180721, WO2016204966, WO2016014974, WO2017127499, WO2017210443, WO2018208864, WO2018237148, WO2018052503, WO2019228406, WO2019234241, WO2019224717, WO2019224711, WO2019078697, WO2020047176, WO2020018820, WO2020212947, WO2022266660, the anti-CD3 antibodies described in each are incorporated herein by reference. [000177] In some embodiments, a need for recruiting a T cell to a cancer cell expressing WT1 for killing the cancer cell exists. In some embodiments, the present disclosure provides means for engaging a T cell to a cancer cell expressing WT1. In some embodiments, the means for engaging a T cell to a cancer cell expressing WT1 is an anti-WT1 / HLA-A2xT cell bispecific antibody described herein. In some embodiments, the present disclosure provides means for eliciting cytotoxic T cell immunity against cancer cells expressing WT1. In some embodiments, the means for eliciting cytotoxic T cell immunity against cancer cells expressing WT1 is an anti-WT1 / HLA-A2xT cell bispecific antibody described herein. [000178] In some embodiments, an anti-WT1 / HLA-A2xT cell bispecific antibody comprises a second antigen binding site that specifically binds to CD3, wherein the improvement comprises a first antigen binding site that specifically binds to a WT1 / HLA-A2 complex that comprises any one of the anti-WT1 / HLA-A2 binding site derived from an anti-WT1 / HLA- A2 antibody described herein (e.g., any one of the anti-WT1 / HLA-A2 antibody described in Table 1). [000179] In some embodiments, an anti-WT1 / HLA-A2 A2xT of the present disclosure comprises a HC CDR1, HC CDR2 and HC CDR3 of a heavy chain variable domain having the amino acid sequence of antibody #1 in row 9; antibody #2 in row 10, antibody #3 in row 11, antibody #4 in row 12, antibody #5 in row 13, antibody #6 in row 14, antibody #7 in row Docket No. A1361.70020WO00 1410150.115, or antibody #8 in row 16, column A of Table 9. Alternatively or in addition, an anti- WT1 / HLA-A2 antibody of the present disclosure comprises a LC CDR1, LC CDR2 and LC CDR3 of antibody #1 in row 9; antibody #2 in row 10, antibody #3 in row 11, antibody #4 in row 12, antibody #5 in row 13, antibody #6 in row 14, antibody #7 in row 15, antibody #8 in row 16, column B of Table 9. [000180] In some embodiments, an anti-WT1 / HLA-A2 A2xT of the present disclosure comprises a HC CDR1, a HC CDR2, a HC CDR3, a LC CDR1, a LC CDR2, and a LC CDR3 having the amino acid sequences of antibody #1 in row 1, antibody #2 in row 2, antibody #3 in row 3, antibody #4 in row 4, antibody #5 in row 5, antibody #6 in row 6, antibody #7 in row 7, or antibody #8 in row 8, columns A and B of Table 8. [000181] In some embodiments, an anti-WT1 / HLA-A2 A2xT of the present disclosure comprises a HC CDR1, a HC CDR2, and a HC CDR3, which collectively contains no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation) as compared with the HC CDR1, the HC CDR2, and the HC CDR3 amino acid sequences of antibody #1 in row 1, antibody #2 in row 2, antibody #3 in row 3, antibody #4 in row 4, antibody #5 in row 5, antibody #6 in row 6, antibody #7 in row 7, or antibody #8 in row 8, column A of Table 8. “Collectively,” as used anywhere in the present disclosure, means that the total number of amino acid variations in all of the three heavy chain CDRs is within the defined range. Alternatively or in addition, the anti-WT1 / HLA-A2 antibody of the present disclosure comprises a LC CDR1, a LC CDR2, and a LC CDR3, which collectively contains no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2 or 1 amino acid variation) as compared with the LC CDR1, the LC CDR2, and the LC CDR3 amino acid sequences of antibody #1 in row 1, antibody #2 in row 2, antibody #3 in row 3, antibody #4 in row 4, antibody #5 in row 5, antibody #6 in row 6, antibody #7 in row 7, or antibody #8 in row 8, column B of Table 8. [000182] In some embodiments, an anti-WT1 / HLA-A2 A2xT of the present disclosure comprises a HC CDR1, a HC CDR2, and a HC CDR3 that collectively are at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to the HC CDR1, the HC CDR2, and the HC CDR3 amino acid sequences of antibody #1 in row 1, antibody #2 in row 2, antibody #3 in row 3, antibody #4 in row 4, antibody #5 in row 5, antibody #6 in row 6, antibody #7 in row 7, or antibody #8 in row 8, column A of Table 8. Alternatively or in addition, the anti-WT1 / HLA-A2 A2xT of the present disclosure comprises Docket No. A1361.70020WO00 1410150.1a LC CDR1, a LC CDR2, and a LC CDR3 that collectively are at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to the LC CDR1, the LC CDR2, and the LC CDR3 amino acid sequences of antibody #1 in row 1, antibody #2 in row 2, antibody #3 in row 3, antibody #4 in row 4, antibody #5 in row 5, antibody #6 in row 6, antibody #7 in row 7, or antibody #8 in row 8, column B of Table 8. [000183] In some embodiments, an anti-WT-1 / HLA-A2 A2xT of the present disclosure comprises: a HC CDR1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation), a HC CDR2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation), and / or a HC CDR3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) as compared with the HC CDR1, the HC CDR2, and the HC CDR3 amino acid sequences of antibody #1 in row 1, antibody #2 in row 2, antibody #3 in row 3, antibody #4 in row 4, antibody #5 in row 5, antibody #6 in row 6, antibody #7 in row 7, or antibody #8 in row 8, column A of Table 8. Alternatively or in addition, the anti-WT1 / HLA-A2 A2xT of the present disclosure comprises: a LC CDR1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) a LC CDR2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation), and / or a LC CDR3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) as compared with the LC CDR1, the LC CDR2, and the LC CDR3 amino acid sequences of antibody #1 in row 1, antibody #2 in row 2, antibody #3 in row 3, antibody #4 in row 4, antibody #5 in row 5, antibody #6 in row 6, antibody #7 in row 7, or antibody #8 in row 8, column B of Table 8. [000184] In some embodiments, an anti-WT1 / HLA-A2 A2xT of the present disclosure comprises: a HC CDR1 that is at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to the HC CDR1, a HC CDR2 that is at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to the HC CDR2, and / or a HC CDR3 that is at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to the HC CDR3 amino acid sequence of antibody #1 in row 1, antibody #2 in row 2, antibody #3 in row 3, antibody #4 in row 4, antibody #5 in row 5, antibody #6 in row 6, antibody #7 in row 7, or antibody #8 in Docket No. A1361.70020WO00 1410150.1row 8, column A of Table 8. Alternatively or in addition, the anti-WT1 / HLA-A2 A2xT of the present disclosure comprises: a LC CDR1 that is at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to the LC CDR1; a LC CDR2 that is at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to the LC CDR2; and / or a LC CDR3 that is at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to the LC CDR3 amino acid sequence of antibody #1 in row 1, antibody #2 in row 2, antibody #3 in row 3, antibody #4 in row 4, antibody #5 in row 5, antibody #6 in row 6, antibody #7 in row 7, or antibody #8 in row 8, column B of Table 8. [000185] In some embodiments, an anti-WT1 / HLA-A2 A2xT of the present disclosure comprises a VH comprising the amino acid sequence of antibody #1 in row 9; antibody #2 in row 10, antibody #3 in row 11, antibody #4 in row 12, antibody #5 in row 1, antibody #6 in row 14, antibody #7 in row 15, antibody #8 in row 16, column A of Table 9. Alternatively or in addition, the anti-WT1 / HLA-A2 A2xT of the present disclosure comprises a VL comprising the amino acid sequence of antibody #1 in row 9; antibody #2 in row 10, antibody #3 in row 11, antibody #4 in row 12, antibody #5 in row 13, antibody #6 in row 14, antibody #7 in row 15, antibody #8 in row 16, column B of Table 9. [000186] In some embodiments, the anti-WT1 / HLA-A2 A2xT of the present disclosure comprises a VH containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) as compared with the VH amino acid sequence of antibody #1 in row 9; antibody #2 in row 10, antibody #3 in row 11, antibody #4 in row 12, antibody #5 in row 13, antibody #6 in row 14, antibody #7 in row 15, antibody #8 in row 16, column A of Table 9. Alternatively or in addition, the anti-WT1 / HLA-A2 A2xT of the present disclosure comprises a VL containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) as compared with the VL amino acid sequence of antibody #1 in row 9; antibody #2 in row 10, antibody #3 in row 11, antibody #4 in row 12, antibody #5 in row 13, antibody #6 in row 14, antibody #7 in row 15, antibody #8 in row 16, column B of Table 9. In some embodiments, the number of amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid Docket No. A1361.70020WO00 1410150.1variation) may occur within a VH amino acid sequence of antibody #1 in row 9; antibody #2 in row 10, antibody #3 in row 11, antibody #4 in row 12, antibody #5 in row 13, antibody #6 in row 14, antibody #7 in row 15, antibody #8 in row 16, column A of Table 9 and / or a VL amino acid sequence of antibody #1 in row 9; antibody #2 in row 10, antibody #3 in row 11, antibody #4 in row 12, antibody #5 in row 13, antibody #6 in row 14, antibody #7 in row 15, antibody #8 in row 16, column B of Table 9 excluding any of the CDR sequences therein. [000187] In some embodiments, an anti-WT1 / HLA-A2 A2xT provided herein comprise a heavy chain variable sequence that comprises a framework sequence that that contains no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation to the framework sequence of a VH amino acid sequence of antibody #1 in row 9; antibody #2 in row 10, antibody #3 in row 11, antibody #4 in row 12, antibody #5 in row 13, antibody #6 in row 14, antibody #7 in row 15, antibody #8 in row 16, column A of Table 9, and / or a light chain variable sequence that comprises a framework sequence that that contains no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation to the framework sequence of a VL amino acid sequence of antibody #1 in row 9; antibody #2 in row 10, antibody #3 in row 11, antibody #4 in row 12, antibody #5 in row 13, antibody #6 in row 14, antibody #7 in row 15, antibody #8 in row 16, column B of Table 9. [000188] In some embodiments, the anti-WT1 / HLA-A2 A2xT of the present disclosure comprises a VH comprising an amino acid sequence that is at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to the VH amino acid sequence of antibody #1 in row 9; antibody #2 in row 10, antibody #3 in row 11, antibody #4 in row 12, antibody #5 in row 13, antibody #6 in row 14, antibody #7 in row 15, antibody #8 in row 16, column A of Table 9. Alternatively or in addition, the anti-WT1 / HLA-A2 A2xT of the present disclosure comprises a VL comprising an amino acid sequence that is at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to the VL antibody #1 in row 9; antibody #2 in row 10, antibody #3 in row 11, antibody #4 in row 12, antibody #5 in row 13, antibody #6 in row 14, antibody #7 in row 15, antibody #8 in row 16, column B of Table 9. [000189] In some embodiments, the degree of sequence variation (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) may occur within a VH of antibody Docket No. A1361.70020WO00 1410150.1#1 in row 9; antibody #2 in row 10, antibody #3 in row 11, antibody #4 in row 12, antibody #5 in row 13, antibody #6 in row 14, antibody #7 in row 15, antibody #8 in row 16, column A of Table 9, and / or a VL of antibody #1 in row 9; antibody #2 in row 10, antibody #3 in row 11, antibody #4 in row 12, antibody #5 in row 13, antibody #6 in row 14, antibody #7 in row 15, antibody #8 in row 16, column B of Table 9 excluding any of the CDR sequences therein. [000190] In some embodiments, an anti-WT1 / HLA-A2 A2xT provided herein comprise a heavy chain variable sequence that is at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to the framework sequence of a VH of antibody #1 in row 9; antibody #2 in row 10, antibody #3 in row 11, antibody #4 in row 12, antibody #5 in row 13, antibody #6 in row 14, antibody #7 in row 15, antibody #8 in row 16, column A of Table 9, and / or a light chain variable sequence that comprises a framework sequence that at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to the framework sequence of a VL of antibody #1 in row 9; antibody #2 in row 10, antibody #3 in row 11, antibody #4 in row 12, antibody #5 in row 13, antibody #6 in row 14, antibody #7 in row 15, antibody #8 in row 16, column B of Table 9. [000191] In some embodiments, an anti-WT1 / HLA-A2xT cell bispecific antibody described herein comprises a second antigen binding site that specifically binds to CD3. [000192] Typically, each of the two antigen binding sites is present within an “arm” of a bispecific antibody. In some embodiments, an arm of a bispecific antibody is configured as a monospecific antibody, e.g., a full-length IgG or a fragment thereof. In some embodiments, a bispecific antibody comprises two arms, one or each of which is configured as an Fv region that confers specificity to distinct antigen residues. In some embodiments, a bispecific antibody comprises two arms of the same configuration in any other suitable format. In some embodiments, a bispecific antibody comprises two arms of two different configurations. In some embodiments, an anti-WT1 / HLA-A2xT cell bispecific antibody comprises a first arm that is configured as a Fab, a Fab’, or a scFv and that comprises the first antigen binding site. In some embodiments, an anti-WT1 / HLA-A2xT cell bispecific antibody comprises a second arm that is configured as a Fab, a Fab’, or a scFv and that comprises the second antigen binding site. In some embodiments, an anti-WT1 / HLA-A2xT cell bispecific antibody comprises a first arm that is configured as an scFv that comprises a first antigen binding site (e.g., a first antigen binding site that specifically binds WT1 / HLA-A2 complex). In some Docket No. A1361.70020WO00 1410150.1embodiments, an anti-WT1 / HLA-A2xT cell bispecific antibody comprises a first arm that is configured as a Fab that comprises a first antigen binding site (e.g., a first antigen binding site that specifically binds WT1 / HLA-A2 complex). In some embodiments, an anti-WT1 / HLA- A2xT cell bispecific antibody comprises a first arm that is configured as a Fab’ that comprises a first antigen binding site (e.g., a first antigen binding site that specifically binds WT1 / HLA-A2 complex). In some embodiments, an anti-WT1 / HLA-A2xT cell bispecific antibody comprises a second arm that is configured as an scFv that comprises a second antigen binding site (e.g., a second antigen binding site that specifically binds CD3). In some embodiments, an anti-WT1 / HLA-A2xT cell bispecific antibody comprises a second arm that is configured as a Fab that comprises a second antigen binding site (e.g., a second antigen binding site that specifically binds CD3). In some embodiments, an anti-WT1 / HLA-A2xT cell bispecific antibody comprises a second arm that is configured as a Fab’ that comprises a second antigen binding site (e.g., a second antigen binding site that specifically binds CD3). [000193] In some embodiments, an anti-WT1 / HLA-A2xT cell bispecific antibody comprises a first arm that is configured as an scFv that comprises a first antigen binding site (e.g., a first antigen binding site that specifically binds WT1 / HLA-A2 complex) and a second arm that is configured as an scFv that comprises a second antigen binding site (e.g., a second antigen binding site that specifically binds CD3). In some embodiments, an anti-WT1 / HLA-A2xT cell bispecific antibody comprises a first arm that is configured as an scFv that comprises a first antigen binding site (e.g., a first antigen binding site that specifically binds WT1 / HLA- A2 complex), and a second arm that is configured as a Fab that comprises a second antigen binding site (e.g., a second antigen binding site that specifically binds CD3). In some embodiments, an anti-WT1 / HLA-A2xT cell bispecific antibody comprises a first arm that is configured as an scFv that comprises a first antigen binding site (e.g., a first antigen binding site that specifically binds WT1 / HLA-A2 complex), and a second arm that is configured as a Fab’ that comprises a second antigen binding site (e.g., a second antigen binding site that specifically binds CD3). In some embodiments, an anti-WT1 / HLA-A2xT cell bispecific antibody comprises a first arm that is configured as a Fab that comprises a first antigen binding site (e.g., a first antigen binding site that specifically binds WT1 / HLA-A2 complex), and a second arm that is configured as a Fab’ that comprises a second antigen binding site (e.g., a second antigen binding site that specifically binds CD3). In some embodiments, an anti-WT1 / HLA-A2xT cell bispecific antibody comprises a first arm that is configured as a Fab that comprises a first antigen binding site (e.g., a first antigen binding site that Docket No. A1361.70020WO00 1410150.1specifically binds WT1 / HLA-A2 complex), and a second arm that is configured as an scFv that comprises a second antigen binding site (e.g., a second antigen binding site that specifically binds CD3). In some embodiments, an anti-WT1 / HLA-A2xT cell bispecific antibody comprises a first arm that is configured as a Fab that comprises a first antigen binding site (e.g., a first antigen binding site that specifically binds WT1 / HLA-A2 complex), and a second arm that is configured as a Fab that comprises a second antigen binding site (e.g., a second antigen binding site that specifically binds CD3). In some embodiments, an anti-WT1 / HLA-A2xT cell bispecific antibody comprises a first arm that is configured as a Fab’ that comprises a first antigen binding site (e.g., a first antigen binding site that specifically binds WT1 / HLA-A2 complex), and a second arm that is configured as a Fab’ that comprises a second antigen binding site (e.g., a second antigen binding site that specifically binds CD3) that is a Fab’. In some embodiments, an anti-WT1 / HLA-A2xT cell bispecific antibody comprises a first arm that is configured as a Fab’ that comprises a first antigen binding site (e.g., a first antigen binding site that specifically binds WT1 / HLA-A2 complex), and a second arm that is configured as a Fab that comprises a second antigen binding site (e.g., a second antigen binding site that specifically binds CD3). In some embodiments, an anti-WT1 / HLA-A2xT cell bispecific antibody comprises a first arm that is configured as a Fab’ that comprises a first antigen binding site (e.g., a first antigen binding site that specifically binds WT1 / HLA-A2 complex), and a second arm that is configured as an scFv that comprises a second antigen binding site (e.g., a second antigen binding site that specifically binds CD3). [000194] In some embodiments, an anti-WT1 / HLA-A2xT cell bispecific antibody does not comprise an Fc region. In some embodiments, the two arms of an anti-WT1 / HLA-A2xT cell bispecific antibody are linked directly. In some embodiments, the two arms of an anti- WT1 / HLA-A2xT cell bispecific antibody are linked by a linker. In some embodiments, an anti-WT1 / HLA-A2xT cell bispecific antibody comprises an Fc region, e.g., a dimeric Fc or a monomeric Fc. In some embodiments, an anti-WT1 / HLA-A2xT cell bispecific antibody comprises a monomeric Fc. In some embodiments, an anti-WT1 / HLA-A2xT cell bispecific antibody comprises one arm linked to one end (e.g., the N terminal) of a monomeric Fc and a second arm linked to the other end (e.g., the C terminal) of the monomeric Fc. In some embodiments, an anti-WT1 / HLA-A2xT cell bispecific antibody comprises a dimeric Fc region. In some embodiments, an anti-WT1 / HLA-A2xT cell bispecific antibody comprises two arms that are oriented symmetrically around an Fc region (e.g., each Fc monomer of a Docket No. A1361.70020WO00 1410150.1dimeric Fc region is linked to one arm). In some embodiments, an anti-WT1 / HLA-A2xT cell bispecific antibody comprises two distinct heavy chains and two distinct light chains, with each heavy chain / light chain pair having different antigen binding specificity. In some embodiments, an anti-WT1 / HLA-A2xT cell bispecific antibody comprises two arms that are oriented asymmetrically around an Fc (e.g., the two arms of the anti-WT1 / HLA-A2xT cell bispecific antibody are linked to one of the monomers of a dimeric Fc region). [000195] In some embodiments, an anti-WT1 / HLA-A2x T cell bispecific antibody comprises a monomeric Fc containing mutations which abolish Fc gamma receptor (FcγR) binding, resulting in loss of effector functions in immune cells that would typically bind FcγRs, such as phagocytosis and cytokine release. In some embodiments, an anti-WT1 / HLA-A2xT cell bispecific antibody comprises a monomeric human serum albumin (HSA). In some embodiments, an anti-WT1 / HLA-A2x T cell bispecific antibody comprises an anti-HSA domain. In some embodiments, an anti-WT1 / HLA-A2x T cell bispecific antibody comprises an anti-HSA domain configured as a VHH antibody. [000196] In some embodiments, the ratio of the first antigen binding site (e.g., a first antigen binding site that specifically binds WT1 / HLA-A2 complex) and a second antigen binding site (e.g., a second antigen binding site that specifically binds CD3) of an anti-WT1 / HLA-A2xT cell bispecific antibody is 1:1, 1:2, 1:3, 1:4, 1:5, 2:3, 2:5, 3:4, 3:5, 4:5, 5:4, 5:3, 5:2, 3:2, 5:1, 4:1, 3:1, or 2:1. In some embodiments, an anti-WT1 / HLA-A2xT cell bispecific antibody comprises a first Fc region and a second Fc region. In some embodiments, an anti- WT1 / HLA-A2xT cell bispecific antibody does not include a Fc region. In some embodiments, an anti-WT1 / HLA-A2xT cell bispecific antibody can be constructed and assembled using any suitable methods into any suitable configurations, e.g., methods and configurations described by Ma et al., Bispecific Antibodies: From Research to Clinical Application, Front. Immunol., 05 May 2021, Sec. Cancer Immunity and Immunotherapy, Volume 12 – 2021, the entire contents are incorporated herein by reference. III. Preparation of an anti-WT1 / HLA-A2 antibody [000197] Antibodies capable of binding WT1 / HLA-A2 as described herein can be made by any method known in the art. See, for example, Harlow and Lane, (1998) Antibodies: A Laboratory Manual, Cold Spring Harbor Laboratory, New York. [000198] In some embodiments, antibodies specific to a target antigen (e.g., WT1 / HLA-A2) can be made by the conventional hybridoma technology. The full-length target antigen or a Docket No. A1361.70020WO00 1410150.1fragment thereof, optionally coupled to a carrier protein such as KLH, can be used to immunize a host animal for generating antibodies binding to that antigen. The route and schedule of immunization of the host animal are generally in keeping with established and conventional techniques for antibody stimulation and production, as further described herein. General techniques for production of mouse, humanized, and human antibodies are known in the art and are described herein. It is contemplated that any mammalian subject including humans or antibody producing cells therefrom can be manipulated to serve as the basis for production of mammalian, including human hybridoma cell lines. Typically, the host animal is inoculated intraperitoneally, intramuscularly, orally, subcutaneously, intraplantar, and / or intradermally with an amount of immunogen, including as described herein. [000199] If desired, an antibody (monoclonal or polyclonal) of interest (e.g., produced by a hybridoma) may be sequenced and the polynucleotide sequence may then be cloned into a vector for expression or propagation. The sequence encoding an antibody of interest may be maintained in vector in a host cell and the host cell can then be expanded and frozen for future use. In an alternative, the polynucleotide sequence may be used for genetic manipulation to "humanize" an antibody or to improve the affinity (affinity maturation), or other characteristics of the antibody. For example, the constant region may be engineered to more resemble human constant regions to avoid immune response if an antibody is used in clinical trials and treatments in humans. It may be desirable to genetically manipulate an antibody sequence to obtain greater affinity to the target antigen and greater efficacy. It will be apparent to one of skill in the art that one or more polynucleotide changes can be made to an antibody and still maintain its binding specificity to the target antigen. [000200] In other embodiments, fully human antibodies can be obtained by using commercially available mice that have been engineered to express specific human immunoglobulin proteins. Transgenic animals that are designed to produce a more desirable (e.g., fully human antibodies) or more robust immune response may also be used for generation of humanized or human antibodies. Examples of such technology are XenomouseRTM from Amgen, Inc. (Fremont, CA) and HuMAb-MouseRTM and TC MouseTM from Medarex, Inc. (Princeton, NJ) or H2L2 mice from Harbour Antibodies BV (Holland). In another alternative, antibodies may be made recombinantly by phage display or yeast technology. See, for example, U.S. Pat. Nos. 5,565,332; 5,580,717; 5,733,743; and 6,265,150; and Winter et al., (1994) Annu. Rev. Immunol. 12:433-455. Alternatively, the phage display technology (McCafferty et al., (1990) Nature 348:552-553) can be used to Docket No. A1361.70020WO00 1410150.1produce human antibodies and antibody fragments in vitro, from immunoglobulin variable (V) domain gene repertoires from unimmunized donors. [000201] Antigen-binding fragments of an intact antibody (full-length antibody) can be prepared via routine methods. For example, F(ab')2 fragments can be produced by pepsin digestion of an antibody molecule, and Fab fragments that can be generated by reducing the disulfide bridges of F(ab')2 fragments. Genetically engineered antibodies, such as humanized antibodies, chimeric antibodies, single-chain antibodies, and bi-specific antibodies, can be produced via, e.g., conventional recombinant technology. In one example, DNA encoding a monoclonal antibodies specific to a target antigen can be readily isolated and sequenced using conventional procedures (e.g., by using oligonucleotide probes that are capable of binding specifically to genes encoding the heavy and light chains of the monoclonal antibodies). The hybridoma cells serve as a preferred source of such DNA. Once isolated, the DNA may be placed into one or more expression vectors, which are then transfected into host cells such as E. coli cells, simian COS cells, Chinese hamster ovary (CHO) cells, human HEK293 cells, or myeloma cells that do not otherwise produce immunoglobulin protein, to obtain the synthesis of monoclonal antibodies in the recombinant host cells. See, e.g., PCT Publication No. WO 87 / 04462. The DNA can then be modified, for example, by substituting the coding sequence for human heavy and light chain constant domains in place of the homologous murine sequences, Morrison et al., (1984) Proc. Nat. Acad. Sci. 81:6851, or by covalently joining to the immunoglobulin coding sequence all or part of the coding sequence for a non-immunoglobulin polypeptide. In that manner, genetically engineered antibodies, such as “chimeric” or “hybrid” antibodies; can be prepared that have the binding specificity of a target antigen. [000202] A single-chain antibody can be prepared via recombinant technology by linking a nucleotide sequence coding for a heavy chain variable region and a nucleotide sequence coding for a light chain variable region. Preferably, a flexible linker is incorporated between the two variable regions. [000203] Alternatively, techniques described for the production of single chain antibodies (U.S. Patent Nos. 4,946,778 and 4,704,692) can be adapted to produce a phage or yeast scFv library and scFv clones specific to WT1 / HLA-A2 can be identified from the library following routine procedures. Positive clones can be subjected to further screening to identify those that have high WT1 / HLA-A2 binding affinity. Docket No. A1361.70020WO00 1410150.1[000204] Antibodies obtained following a method known in the art and described herein can be characterized using methods well known in the art. For example, one method is to identify the epitope to which the antigen binds, or “epitope mapping.” There are many methods known in the art for mapping and characterizing the location of epitopes on proteins, including solving the crystal structure of an antibody-antigen complex, competition assays, gene fragment expression assays, and synthetic peptide-based assays, as described, for example, in Chapter 11 of Harlow and Lane, Using Antibodies, a Laboratory Manual, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y., 1999. In one example, epitope mapping can be accomplished using H / D-Ex (hydrogen deuterium exchange) coupled with proteolysis and mass spectrometry. In an additional example, epitope mapping can be used to determine the sequence to which an antibody binds. The epitope can be a linear epitope, i.e., contained in a single stretch of amino acids, or a conformational epitope formed by a three- dimensional interaction of amino acids that may not necessarily be contained in a single stretch (primary structure linear sequence). Peptides of varying lengths (e.g., at least 4-6 amino acids long) can be isolated or synthesized (e.g., recombinantly) and used for binding assays with an antibody. In another example, the epitope to which an antibody binds can be determined in a systematic screening by using overlapping peptides derived from the target antigen sequence and determining binding by the antibody. According to the gene fragment expression assays, the open reading frame encoding the target antigen is fragmented either randomly or by specific genetic constructions and the reactivity of the expressed fragments of the antigen with an antibody to be tested is determined. The gene fragments may, for example, be produced by PCR and then transcribed and translated into protein in vitro, in the presence of radioactive amino acids. The binding of an antibody to the radioactively labeled antigen fragments is then determined by immunoprecipitation and gel electrophoresis. Certain epitopes can also be identified by using large libraries of random peptide sequences displayed on the surface of phage particles (phage libraries). Alternatively, a defined library of overlapping peptide fragments can be tested for binding to the test antibody in simple binding assays. In an additional example, mutagenesis of an antigen binding domain, domain swapping experiments and alanine scanning mutagenesis can be performed to identify residues required, sufficient, and / or necessary for epitope binding. Alternatively, competition assays can be performed using other antibodies known to bind to the same antigen to determine whether an antibody binds to the same epitope as the other antibodies. Competition assays are well known to those of skill in the art. Docket No. A1361.70020WO00 1410150.1[000205] In some examples, an anti-WT1 / HLA-A2 antibody is prepared by recombinant technology as exemplified below. Nucleic acids encoding the heavy and light chain of an anti-WT1 / HLA-A2 antibody as described herein can be cloned into one expression vector, each nucleotide sequence being in operable linkage to a suitable promoter. In one example, each of the nucleotide sequences encoding the heavy chain and light chain is in operable linkage to a distinct promoter. Alternatively, the nucleotide sequences encoding the heavy chain and the light chain can be in operable linkage with a single promoter, such that both heavy and light chains are expressed from the same promoter. When necessary, an internal ribosomal entry site (IRES) can be inserted between the heavy chain and light chain encoding sequences. [000206] In some examples, the nucleotide sequences encoding the two chains of an antibody are cloned into two vectors, which can be introduced into the same or different cells. When the two chains are expressed in different cells, each of them can be isolated from the host cells expressing such and the isolated heavy chains and light chains can be mixed and incubated under suitable conditions allowing for the formation of an antibody. [000207] Generally, a nucleic acid sequence encoding one or all chains of an antibody can be cloned into a suitable expression vector in operable linkage with a suitable promoter using methods known in the art. For example, the nucleotide sequence and vector can be contacted, under suitable conditions, with a restriction enzyme to create complementary ends on each molecule that can pair with each other and be joined together with a ligase. Alternatively, synthetic nucleic acid linkers can be ligated to the termini of a gene. These synthetic linkers contain nucleic acid sequences that correspond to a particular restriction site in the vector. The selection of expression vectors / promoter would depend on the type of host cells for use in producing antibodies. [000208] A variety of promoters can be used for expression of the antibodies described herein, including, but not limited to, cytomegalovirus (CMV) intermediate early promoter, a viral LTR such as the Rous sarcoma virus LTR, HIV-LTR, HTLV-1 LTR, the simian virus 40 (SV40) early promoter, E. coli lac UV promoter, and the herpes simplex tk virus promoter. [000209] Regulatable promoters can also be used. Such regulatable promoters include those using the lac repressor from E. coli as a transcription modulator to regulate transcription from lac operator bearing mammalian cell promoters [[Brown, M. et al., Cell, 49:603-612 (1987)]], those using the tetracycline repressor (tetR) [[Gossen, M., and Bujard, H., Proc. Natl. Acad. Docket No. A1361.70020WO00 1410150.1Sci. USA 89:5547-555115 (1992); Yao, F. et al., Human Gene Therapy, 9:1939-1950 (1998); Shockelt, P., et al., Proc. Natl. Acad. Sci. USA, 92:6522-6526 (1995)]]. Other systems include FK506 dimer, VP16 or p65 using astradiol, RU486, diphenol murislerone, or rapamycin. Inducible systems are available from Invitrogen, Clontech and Ariad, among others. [000210] Regulatable promoters that include a repressor with the operon can be used. In one embodiment, the lac repressor from E. coli can function as a transcriptional modulator to regulate transcription from lac operator-bearing mammalian cell promoters [[M. Brown et al., Cell, 49:603-612 (1987)]]; Gossen and Bujard (1992); [[M. Gossen et al., Natl. Acad. Sci. USA, 89:5547-5551(1992)]] combined the tetracycline repressor (tetR) with the transcription activator (VP 16) to create a tetR-mammalian cell transcription activator fusion protein, tTa (tetR-VP 16), with the tetO bearing minimal promoter derived from the human cytomegalovirus (hCMV) promoter to create a tetR-tet operator system to control gene expression in mammalian cells. In one embodiment, a tetracycline inducible switch is used. The tetracycline repressor (tetR) alone, rather than the tetR-mammalian cell transcription factor fusion derivatives can function as potent trans-modulator to regulate gene expression in mammalian cells when the tetracycline operator is properly positioned downstream for the TATA element of the CMVIE promoter (Yao et al., Human Gene Therapy). One particular advantage of this tetracycline inducible switch is that it does not require the use of a tetracycline repressor-mammalian cells transactivator or repressor fusion protein, which in some instances can be toxic to cells (Gossen 5 et al., Natl. Acad. Sci. USA, 89:5547-5551 (1992); Shockett et al., Proc. Natl. Acad. Sci. USA, 92:6522-6526 (1995)), to achieve its regulatable effects. [000211] Additionally, the vector can contain, for example, some or all of the following: a selectable marker gene, such as the neomycin gene for selection of stable or transient transfectants in mammalian cells; enhancer / promoter sequences from the immediate early gene of human CMV for high levels of transcription; transcription termination and RNA processing signals from SV40 for mRNA stability; SV40 polyoma origins of replication and ColE1 for proper episomal replication; internal ribosome binding sites (IRESes), versatile multiple cloning sites; and T7 and SP6 RNA promoters for in vitro transcription of sense and antisense RNA. Suitable vectors and methods for producing vectors containing transgenes are well known and available in the art. Examples of polyadenylation signals useful to practice the methods described herein include, but are not limited to, human collagen I Docket No. A1361.70020WO00 1410150.1polyadenylation signal, human collagen II polyadenylation signal, and SV40 polyadenylation signal. [000212] One or more vectors (e.g., expression vectors) comprising nucleic acids encoding any of antibodies (e.g., the nucleic acid coding sequence listed in Table 3) may be introduced into suitable host cells for producing the antibodies. Non-limiting examples of the host cells include Chinese hamster ovary (CHO) cells, dhfr- CHO cell, human embryonic kidney (HEK)-293 cells, verda reno (VERO) cells, nonsecreting null (NS0) cells, human embryonic retinal (PER.C6) cells, Sp2 / 0 cells, baby hamster kidney (BHK) cells, Madin-Darby Canine Kidney (MDCK) cells, Madin-Darby Bovine Kidney (MDBK) cells, and monkey kidney CV1 line transformed by SV40 (COS) cells. In some embodiments, the host cell expressing an anti-WT1 / HLA-A2 antibody are CHO cells. The host cells can be cultured under suitable conditions for expression of an antibody or any polypeptide chain thereof. Such antibodies or polypeptide chains thereof can be recovered by the cultured cells (e.g., from the cells or the culture supernatant) via a conventional method, e.g., affinity purification. If necessary, polypeptide chains of an antibody can be incubated under suitable conditions for a suitable period of time allowing for production of the antibody. In some embodiments, the host cell comprises the nucleic acid encoding the heavy chain of the anti-WT1 / HLA-A2 antibody. In some embodiments, the host cell comprises the nucleic acid encoding the light chain of the anti-WT1 / HLA-A2 antibody. In some embodiments, the host cell comprises the nucleic acid encoding the heavy chain and the nucleic acid encoding the light chain. [000213] In some embodiments, methods for preparing an antibody described herein involve a recombinant expression vector that encodes both the heavy chain and the light chain of an anti-WT1 / HLA-A2 antibody, as also described herein. The recombinant expression vector can be introduced into a suitable host cell (e.g., a dhfr- CHO cell) by a conventional method, e.g., calcium phosphate mediated transfection. Positive transformant host cells can be selected and cultured under suitable conditions allowing for the expression of the two polypeptide chains that form an antibody, which can be recovered from the cells or from the culture medium. When necessary, the two chains recovered from the host cells can be incubated under suitable conditions allowing for the formation of an antibody. [000214] In one example, two recombinant expression vectors are provided, one encoding the heavy chain of the anti-WT1 / HLA-A2 antibody and the other encoding the light chain of the anti-WT1 / HLA-A2 antibody. Both of the two recombinant expression vectors can be Docket No. A1361.70020WO00 1410150.1introduced into a suitable host cell (e.g., dhfr- CHO cell) by a conventional method, e.g., calcium phosphate-mediated transfection. [000215] Alternatively, each of the expression vectors can be introduced into a suitable host cells. Positive transformants can be selected and cultured under suitable conditions allowing for the expression of the polypeptide chains of an antibody. When the two expression vectors are introduced into the same host cells, an antibody produced therein can be recovered from the host cells or from the culture medium. If necessary, the polypeptide chains can be recovered from the host cells or from the culture medium and then incubated under suitable conditions allowing for formation of an antibody. When the two expression vectors are introduced into different host cells, each of them can be recovered from the corresponding host cells or from the corresponding culture media. The two polypeptide chains can then be incubated under suitable conditions for formation of an antibody. [000216] Standard molecular biology techniques are used to prepare the recombinant expression vector, transfect the host cells, select for transformants, culture the host cells and recovery of the antibodies from the culture medium. For example, some antibodies can be isolated by affinity chromatography with a Protein A or Protein G coupled matrix. [000217] Any of the nucleic acids encoding the heavy chain, the light chain, or both of an anti-WT1 / HLA-A2 antibody as described herein (e.g., as provided in Table 3), vectors (e.g., expression vectors) containing such; and host cells comprising the vectors are within the scope of the present disclosure. [000218] Table 3: Nucleic acids sequences encoding the VH / VL of anti-WT1 / HLA-A2 antibodies listed in Table. Binder / Antibody Nucleic Acid Sequences SEQ IDDocket No. A1361.70020WO00 1410150.1anti- VHCAGGTGCAGCTGCAGGAGTCGGGCCCAGGACTGGTGAAGCCTTCG43 WT1 / HLA-A2 GAGACCCTGTCCCTCACCTGCACTGTCTCTGGTGGCTCCATCAGTDocket No. A1361.70020WO00 1410150.1AAGTTCAGCGGCAGTGGATCTGGGACAGATTTCACTCTCACCATC AGCAGCCTGCAGCCTGAAGATTTTGCAACTTATTACTGCCAACAG[000219] In some embodiments, the present disclosure provides an isolated nucleic acid comprising a sequence at least 60% (e.g., 60%, 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO: 39. In some Docket No. A1361.70020WO00 1410150.1embodiments, the present disclosure provides an isolated nucleic acid comprising a sequence at least 60% (e.g., 60%, 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO: 40. [000220] In some embodiments, the present disclosure provides an isolated nucleic acid comprising a sequence at least 60% (e.g., 60%, 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO: 43. In some embodiments, the present disclosure provides an isolated nucleic acid comprising a sequence at least 60% (e.g., 60%, 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO: 44. [000221] In some embodiments, the present disclosure provides an isolated nucleic acid comprising a sequence at least 60% (e.g., 60%, 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO: 47. In some embodiments, the present disclosure provides an isolated nucleic acid comprising a sequence a nucleic acid at least 60% (e.g., 60%, 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO: 48. [000222] In some embodiments, the present disclosure provides an isolated nucleic acid comprising a sequence at least 60% (e.g., 60%, 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO: 51. In some embodiments, the present disclosure provides an isolated nucleic acid comprising a sequence at least 60% (e.g., 60%, 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO: 52. [000223] In some embodiments, the present disclosure provides an isolated nucleic acid comprising a sequence at least 60% (e.g., 60%, 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO: 55. In some embodiments, the present disclosure provides an isolated nucleic acid comprising a sequence at least 60% (e.g., 60%, 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO: 56. [000224] In some embodiments, the present disclosure provides an isolated nucleic acid comprising a sequence at least 60% (e.g., 60%, 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO: 99. In some embodiments, the present disclosure provides an isolated nucleic acid comprising a sequence at least 60% (e.g., 60%, 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO: 100. Docket No. A1361.70020WO00 1410150.1[000225] In some embodiments, the present disclosure provides an isolated nucleic acid comprising a sequence at least 60% (e.g., 60%, 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO: 101. In some embodiments, the present disclosure provides an isolated nucleic acid comprising a sequence at least 60% (e.g., 60%, 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO: 102. [000226] In some embodiments, the present disclosure provides an isolated nucleic acid comprising a sequence at least 60% (e.g., 60%, 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO: 103. In some embodiments, the present disclosure provides an isolated nucleic acid comprising a sequence at least 60% (e.g., 60%, 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO: 104. [000227] In some embodiments, the present disclosure provides an expression vector encoding the anti-WT1 / HLA-A2 antibody described herein. [000228] In some embodiments, the expression vector comprises an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 39. In some embodiments, the expression vector comprises an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 40. In some embodiments, the expression vector comprises an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 39, and an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 40. [000229] In some embodiments, the anti-WT1 / HLA-A2 antibody described herein is produced by expressing in a recombinant cell: (i) an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, Docket No. A1361.70020WO00 1410150.1at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 39, and / or (ii) an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 40. [000230] In some embodiments, the anti-WT1 / HLA-A2 antibody described herein is produced by expressing in a recombinant cell an expression vector comprising: (i) an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 39, and / or (ii) an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 40. [000231] In some embodiments, the present disclosure provides an expression vector encoding the anti-WT1 / HLA-A2 antibody described herein. In some embodiments, the expression vector comprises an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 43. In some embodiments, the expression vector comprises an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 44. In some embodiments, the expression vector comprises an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 43, and an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 44. [000232] In some embodiments, the anti-WT1 / HLA-A2 antibody described herein is produced by expressing in a recombinant cell: (i) an isolated nucleic acid at least 60% (e.g., Docket No. A1361.70020WO00 1410150.1at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 43, and / or (ii) an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 44. [000233] In some embodiments, the anti-WT1 / HLA-A2 described herein is produced by expressing in a recombinant cell an expression vector comprising: (i) an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 43, and / or (ii) an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 44. [000234] In some embodiments, the present disclosure provides an expression vector encoding the anti-WT1 / HLA-A2 antibody described herein. In some embodiments, the expression vector comprises an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 47. In some embodiments, the expression vector comprises an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 48. In some embodiments, the expression vector comprises an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 47, and an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 48. Docket No. A1361.70020WO00 1410150.1[000235] In some embodiments, the anti-WT1 / HLA-A2 antibody described herein is produced by expressing in a recombinant cell: (i) an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 47, and / or (ii) an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 48. [000236] In some embodiments, the anti-WT1 / HLA-A2 described herein is produced by expressing in a recombinant cell an expression vector comprising: (i) an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 47, and / or (ii) an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 48. [000237] In some embodiments, the present disclosure provides an expression vector encoding the anti-WT1 / HLA-A2 antibody described herein. In some embodiments, the expression vector comprises an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 51. In some embodiments, the expression vector comprises an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 52. In some embodiments, the expression vector comprises an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 51, and an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least Docket No. A1361.70020WO00 1410150.193%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 52. [000238] In some embodiments, the anti-WT1 / HLA-A2 antibody described herein is produced by expressing in a recombinant cell: (i) an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 51, and / or (ii) an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 52. [000239] In some embodiments, the anti-WT1 / HLA-A2 described herein is produced by expressing in a recombinant cell an expression vector comprising: (i) an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 51, and / or (ii) an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 52. [000240] In some embodiments, the present disclosure provides an expression vector encoding the anti-WT1 / HLA-A2 antibody described herein. In some embodiments, the expression vector comprises an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 55. In some embodiments, the expression vector comprises an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 56. In some embodiments, the expression vector comprises an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ Docket No. A1361.70020WO00 1410150.1ID NO: 55, and an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 56. [000241] In some embodiments, the anti-WT1 / HLA-A2 antibody described herein is produced by expressing in a recombinant cell: (i) an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 55, and / or (ii) an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 56. [000242] In some embodiments, the anti-WT1 / HLA-A2 described herein is produced by expressing in a recombinant cell an expression vector comprising: (i) an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 55, and / or (ii) an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 56. [000243] In some embodiments, the present disclosure provides an expression vector encoding the anti-WT1 / HLA-A2 antibody described herein. In some embodiments, the expression vector comprises an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 99. In some embodiments, the expression vector comprises an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 100. In some embodiments, the expression vector comprises an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, Docket No. A1361.70020WO00 1410150.1at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 99, and an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 100. [000244] In some embodiments, the anti-WT1 / HLA-A2 antibody described herein is produced by expressing in a recombinant cell: (i) an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 99, and / or (ii) an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 100. [000245] In some embodiments, the anti-WT1 / HLA-A2 described herein is produced by expressing in a recombinant cell an expression vector comprising: (i) an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 99, and / or (ii) an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 100. [000246] In some embodiments, the present disclosure provides an expression vector encoding the anti-WT1 / HLA-A2 antibody described herein. In some embodiments, the expression vector comprises an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 101. In some embodiments, the expression vector comprises an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) Docket No. A1361.70020WO00 1410150.1identical to SEQ ID NO: 102. In some embodiments, the expression vector comprises an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 101, and an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 102. [000247] In some embodiments, the anti-WT1 / HLA-A2 antibody described herein is produced by expressing in a recombinant cell: (i) an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 101, and / or (ii) an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 102. [000248] In some embodiments, the anti-WT1 / HLA-A2 described herein is produced by expressing in a recombinant cell an expression vector comprising: (i) an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 101, and / or (ii) an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 102. [000249] In some embodiments, the present disclosure provides an expression vector encoding the anti-WT1 / HLA-A2 antibody described herein. In some embodiments, the expression vector comprises an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 101. In some embodiments, the expression vector comprises an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, Docket No. A1361.70020WO00 1410150.1at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 102. In some embodiments, the expression vector comprises an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 101, and an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 102. [000250] In some embodiments, the anti-WT1 / HLA-A2 antibody described herein is produced by expressing in a recombinant cell: (i) an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 101, and / or (ii) an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 102. [000251] In some embodiments, the anti-WT1 / HLA-A2 described herein is produced by expressing in a recombinant cell an expression vector comprising: (i) an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 101, and / or (ii) an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 102. [000252] In some embodiments, the present disclosure provides an expression vector encoding the anti-WT1 / HLA-A2 antibody described herein. In some embodiments, the expression vector comprises an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least Docket No. A1361.70020WO00 1410150.199%, or 100%) identical to SEQ ID NO: 103. In some embodiments, the expression vector comprises an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 104. In some embodiments, the expression vector comprises an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 103, and an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 104. [000253] In some embodiments, the anti-WT1 / HLA-A2 antibody described herein is produced by expressing in a recombinant cell: (i) an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 103, and / or (ii) an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 104. [000254] In some embodiments, the anti-WT1 / HLA-A2 described herein is produced by expressing in a recombinant cell an expression vector comprising: (i) an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 103, and / or (ii) an isolated nucleic acid at least 60% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 104. [000255] In some embodiments, the present disclosure provides a recombinant cell (e.g., a recombinant cell for producing an antibody) expressing the anti-WT1 / HLA-A2 antibody described herein. Docket No. A1361.70020WO00 1410150.1[000256] Accordingly, the present disclosure provides methods for producing an antibody, the methods comprising culturing the recombinant cells under conditions suitable for expression of the antibody from the expression vector by the recombinant cell. Recombinant cells expressing an antibody can be cultured in any suitable condition known in the art. In some embodiments, the method further comprises isolating an antibody from the culture media in which the cell or cells were cultured using any suitable known methods in the art. IV. Pharmaceutical Composition [000257] Antibodies, as well as the encoding nucleic acids or nucleic acid sets, vectors comprising such, or host cells comprising the vectors, as described herein can be mixed with a pharmaceutically acceptable carrier (excipient) to form a pharmaceutical composition for use in treating a target disease. “Acceptable” means that the carrier must be compatible with the active ingredient of the composition (and preferably, capable of stabilizing the active ingredient) and not deleterious to the subject to be treated. Pharmaceutically acceptable excipients (carriers) including buffers, which are well known in the art. See, e.g., Remington: The Science and Practice of Pharmacy 20th Ed. (2000) Lippincott Williams and Wilkins, Ed. K. E. Hoover. [000258] The anti-WT1 / HLA-A2 antibody containing pharmaceutical composition disclosed herein may further comprise a suitable buffer agent. A buffer agent is a weak acid or base used to maintain the pH of a solution near a chosen value after the addition of another acid or base. In some examples, the buffer agent disclosed herein can be a buffer agent capable of maintaining physiological pH despite changes in carbon dioxide concentration (produced by cellular respiration). Exemplary buffer agents include, but are not limited to, a HEPES (4-(2- hydroxyethyl)-1-piperazineethanesulfonic acid) buffer, Dulbecco's phosphate-buffered saline (DPBS) buffer, or Phosphate-buffered Saline (PBS) buffer. Such buffers may comprise disodium hydrogen phosphate and sodium chloride, or potassium dihydrogen phosphate and potassium chloride. [000259] In some embodiments, the buffer agent in the pharmaceutical composition described herein may maintain a pH value of about 5-8. For example, the pH of the pharmaceutical composition can be about 7.1, 7.2, 7.3, 7.4, 7.5, 7.6, 7.7, 7.8, 7.9, or 8.0. In other examples, the pharmaceutical composition may have a pH value lower than 7, for example, about 7, 6.8, 6.5, 6.3, 6, 5.8, 5.5, 5.3, or 5. [000260] The pharmaceutical composition described herein comprises one or more suitable Docket No. A1361.70020WO00 1410150.1salts. A salt is an ionic compound that can be formed by the neutralization reaction of an acid and a base. (Skoog, D.A; West, D.M.; Holler, J.F.; Crouch, S.R. (2004). “Chapters 14–16”. Fundamentals of Analytical Chemistry (8th ed.)). Salts are composed of related numbers of cations (positively charged ions) and anions (negative ions) so that the product is electrically neutral (without a net charge). [000261] In some embodiments, the pharmaceutical compositions can comprise pharmaceutically acceptable carriers, excipients, or stabilizers in the form of lyophilized formulations or aqueous solutions. (Remington: The Science and Practice of Pharmacy 20th Ed. (2000) Lippincott Williams and Wilkins, Ed. K. E. Hoover). In some embodiments, the pharmaceutical composition can be formulated for intravenous injection. In some embodiments, the pharmaceutical composition can be formulated for subcutaneous injection. The pharmaceutical compositions to be used for in vivo administration must be sterile. This is readily accomplished by, for example, filtration through sterile filtration membranes. Therapeutic antibody compositions are generally placed into a container having a sterile access port, for example, an intravenous or subcutaneous solution bag or vial having a stopper pierceable by a hypodermic injection needle. V. Methods of Use [000262] Aspects of the disclosure relate to compositions and methods for treating cancer. WT1 is over-expressed in hematological malignancies and has been ranked among the top tumor antigens (Van Driessche, et al., The Oncologist, 2012. 17(2):250-259). Despite its high expression in cancers, therapies to specifically target WT1-expressing tumor cells have remained elusive due to the high homology shared with other endogenous peptides. For example, peptides of the M13L and PIGQ proteins are top off-target peptides in targeting WT1 (Ataie et al., J Mol Biol, 2016. 428(1):194-205). This is problematic because inadvertently targeting these proteins can result in poor outcomes, such as diseases associated with their loss (e.g., epilepsy). Thus, the discovery of antibodies that target WT1 and WT1 / HLA-A2 complexes with high specificity and little-to-no off-targeting binding was unexpected and represents a profound advancement in cancer therapeutics. [000263] WT1 is a transcription factor and is therefore expressed in the nucleus in normal cells. However, in cancerous cells, WT1 is processed by the proteosome and presented on Docket No. A1361.70020WO00 1410150.1MHC / HLA molecules, forming a WT1 / MHC complex (e.g., a WT1 / MHC-I complex) or WT1 / HLA (e.g., a WT1 / HLA-A2 complex). [000264] An anti-WT1 / HLA-A2 antibody comprise two binding moieties, one that specifically binds to WT1 / HLA-A2. In some embodiments, the second binding moiety specifically binds to a T cell antigen. In some embodiments, the T cell antigen is a CD3 complex. In some embodiments, the second binding moiety specifically binds to CD3δ of the CD3 complex. In some embodiments, the second binding moiety specifically binds to CD3ε of the CD3 complex. In some embodiments, the second binding moiety specifically binds to CD3γ of the CD3 complex. In some embodiments, the second binding moiety specifically binds to a CD3δ / ε heterodimer of the CD3 complex. In some embodiments, the second binding moiety specifically binds to a CD3ε / γ heterodimer of the CD3 complex. By binding WT1 / HLA-A2 with a first binding moiety and a T cell antigen with a second binding moiety, an anti-WT1 / HLA-A2 antibody direct cytotoxic T cells against WT1 / HLA-A2 expressing cancer cells, inducing death in those cancer cells. [000265] In some aspects, the disclosure features a method for treating cancer (e.g., cancer expressing WT1), the method comprising administering to a subject in need an effective amount of a therapeutic agent, wherein the therapeutic agent is or comprises: (i) any one or more of the antibodies or antigen-binding fragments thereof described herein (including conjugates), (ii) any one or more of the fusion proteins described herein, (iii) any one or more of the bispecific or multispecific polypeptides described herein; (iv) any one or more of the nucleic acids described herein; (v) any one or more of the expression vectors described herein; (vi) any one or more of the recombinant cells described herein; (vii) any one or more of the isolated polypeptides described herein; and / or (viii) any one or more of the pharmaceutical compositions described herein. [000266] In certain embodiments, the therapeutic agent can be administered through injection by intravenous, intraperitoneal, intracerebral (intra-parenchymal), intracerebroventricular, intramuscular, subcutaneously, intra-ocular, intraarterial, intraportal, or intralesional routes; by sustained release systems or by implantation devices. In certain embodiments, the compositions can be administered by bolus injection or continuously by infusion, or by implantation device. [000267] Determination of whether an amount of an antibody (e.g., anti-WT1 antibody) achieved the therapeutic effect would be evident to one of skill in the art based on the teachings provided herein. Effective amounts vary, as recognized by those skilled in the art, Docket No. A1361.70020WO00 1410150.1depending on the particular condition being treated, the severity of the condition, the individual patient parameters including age, physical condition, size, gender and weight, the duration of the treatment, the nature of concurrent therapy (if any), the specific route of administration and like factors within the knowledge and expertise of the health practitioner. The particular dosage regimen, i.e., dose, timing and repetition, used in the method described herein will depend on the particular subject and that subject's medical history, as discussed herein. [000268] Empirical considerations, such as time to maximum effect, the half-life, and / or time above a specific concentration generally will contribute to the determination of the dosage. For example, antibodies that are compatible with the human immune system, such as humanized antibodies or fully human antibodies, may be used to prolong half-life of an antibody and to prevent the antibody being attacked by the host's immune system. Other reasons for dose-adjusting include differences in pharmacokinetics or pharmacodynamic response driven by sex, age, individual response, polymorphisms on an antibody target and / or receptors involved in antibody clearance. Frequency of administration may be determined and adjusted over the course of therapy, and is generally, but not necessarily, based on treatment and / or suppression and / or amelioration and / or delay of a target disease / disorder. Alternatively, sustained continuous release formulations of an antibody may be appropriate. Various formulations and devices for achieving sustained release are known in the art. [000269] Dosing frequencies may vary in accordance with the claimed methods. In some embodiments, a composition may be administered once. In some embodiments, a composition will be administered on multiple occasions. In some embodiments, dosing frequency is every week, every 2 weeks, every 3 weeks, every 4 weeks, every 5 weeks, every 6 weeks, every 7 weeks, every 8 weeks, every 9 weeks, or every 10 weeks; or once every month, every 2 months, or every 3 months, or longer. In some embodiments, a composition will be administered daily, biweekly, weekly, bimonthly, monthly, or at any time interval that provides suitable (e.g., maximal) efficacy while minimizing safety risks to the subject. Generally, the efficacy and the treatment and safety risks may be monitored throughout the course of treatment. [000270] In some embodiments, a subject may be administered a composition provided herein (e.g., an anti-WT1 / HLA-A2 antibody) at one or more intervals during a set period of time. In some cases, periods of time during which a subject is administered a composition at one or more intervals may be separated by periods of time in which the subject is not Docket No. A1361.70020WO00 1410150.1administered the composition. In some embodiments, the relative durations of respective periods of time may depend on the subject’s response to treatment or severity of disease or both and / or may be determined based on the judgment of a treating physician. [000271] In some embodiments, an antibody can be administered parenterally. For example, a parenterally administered composition may be administered by subcutaneous, intracutaneous, intravenous, intraperitoneal, intratumor, intramuscular, intraarticular, intraarterial, or infusion techniques. In addition, it can be administered to the subject via injectable depot routes of administration such as using 1-, 3-, or 6-month depot injectable or biodegradable materials and methods. [000272] In some embodiments, an antibody (e.g., an anti-WT1 / HLA-A2 antibody) is administered intravenously. In some embodiments, an antibody (e.g., an anti-WT1 / HLA-A2 antibody) is administered subcutaneously. [000273] For intravenous injection, water soluble antibodies can be administered by the drip method, whereby a pharmaceutical formulation containing an antibody and a physiologically acceptable excipient is infused. Physiologically acceptable excipients may include, for example, 5% dextrose, 0.9% saline. Ringer’s solution or other suitable excipients. Other injectable compositions may contain various carriers such as vegetable oils, dimethylactamide, dimethyformamide, ethyl lactate, ethyl carbonate, isopropyl myristate, ethanol, and polyols (glycerol, propylene glycol, liquid polyethylene glycol, and the like). In some cases, preparations, e.g., a sterile formulation of a suitable soluble salt form of an antibody, can be dissolved and administered in a pharmaceutical excipient such as Water-for- Injection, 0.9% saline, or 5% glucose solution. [000274] In one embodiment, an antibody is administered via site-specific or targeted local delivery techniques. Examples of site-specific or targeted local delivery techniques include various implantable depot sources of an antibody or local delivery catheters, such as infusion catheters, an indwelling catheter, or a needle catheter, synthetic grafts, adventitial wraps, shunts and stents or other implantable devices, site specific carriers, direct injection, or direct application. See, e.g., PCT Publication No. WO 00 / 53211 and U.S. Pat. No. 5,981,568. [000275] In some embodiments, more than one antibody, or a combination of an antibody and another suitable therapeutic agent, may be administered to a subject in need of the treatment. An antibody can also be used in conjunction with other agents that serve to enhance and / or complement the effectiveness of the agents. Treatment efficacy for a target disease / disorder can be assessed by methods well-known in the art. Docket No. A1361.70020WO00 1410150.1[000276] The anti-WT1 / HLA-A2 antibody and treatment methods involving such as described in the present disclosure may be utilized in combination with other types of therapy for the target disease or disorder disclosed herein. In this context, an antibody composition and a therapeutic agent may be given either simultaneously or sequentially. Examples include chemotherapy, immune therapy, surgery, radiation, gene therapy, and so forth, or anti- infection therapy. Such therapies can be administered simultaneously or sequentially (in any order) with the treatment according to the present disclosure. [000277] For example, the combination therapy can include the anti-WT1 / HLA-A2 antibody and pharmaceutical composition described herein, co-formulated with and / or co-administered with, at least one additional therapeutic agent. Such combination therapies may advantageously utilize lower dosages of the administered therapeutic agents, thus preventing possible toxicities or complications associated with the various monotherapies. [000278] In some embodiments, the antibodies described herein are conjugated directly or indirectly to one or more molecular payloads or labels. For example, in some embodiments, antibodies described herein are conjugated to molecular payload, e.g., a molecular payload providing a therapeutic benefit for a subject, e.g., an antibody-drug conjugate (ADC). Accordingly, in some embodiments, methods are provided for delivering a molecular payloads to a subject for therapeutic purposes. In such embodiments, the molecular payload may be a small molecule, protein, nucleic acid, oligonucleotide, or any molecular entity capable of modulating the activity or function of a gene, protein, and / or nucleic acid, e.g., in a cell. In some embodiments, the molecular payload is a cytotoxic agent or a chemotherapeutic agent. [000279] An anti-WT1 / HLA-A2 antibody disclosed herein can also be used for detecting presence of WT1 / HLA-A2 complexes in vitro or in vivo. Results obtained from such detection methods can be used for diagnostic purposes (e.g., diagnosing diseases associated with WT1 / HLA-A2) or for scientific research purposes (e.g., identifying new WT1 secreting cell types, studying bioactivity and / or regulation of secreted WT1). For assay uses such as diagnostic uses, an anti-WT1 / HLA-A2 antibody as described herein may be conjugated with a detectable label (e.g., an imaging agent such as a contrast agent) for detecting presence of WT1 / HLA-A2 complexes, either in vivo or in vitro. [000280] In other embodiments, an anti-WT1 / HLA-A2 antibody as described herein can be attached to a detectable label, which is a compound that is capable of releasing a detectable signal, either directly or indirectly, such that the aptamer can be detected, measured, and / or Docket No. A1361.70020WO00 1410150.1qualified, in vitro or in vivo. Examples of such “detectable labels" are intended to include, but are not limited to, fluorescent labels, chemiluminescent labels, colorimetric labels, enzymatic markers, radioactive isotopes, and affinity tags such as biotin. Such labels can be conjugated to the aptamer, directly or indirectly, by conventional methods. [000281] In some embodiments, the detectable label is an agent suitable for detecting WT1 expressing cells in vitro, which can be a radioactive molecule, a radiopharmaceutical, or an iron oxide particle. Radioactive molecules suitable for in vivo imaging include, but are not limited to,122I,123I,124I,125I,131I,18F,75Br,76Br,77Br,211At,225Ac,177Lu,153Sm,186Re,188Re,67Cu,213Bi,212Bi,212Pb, and67Ga. Exemplary radiopharmaceuticals suitable for in vivo imaging include111In Oxyquinoline,131I Sodium iodide,99mTc Mebrofenin, and99mTc Red Blood Cells,123I Sodium iodide,99mTc Exametazime,99mTc Macroaggregate Albumin,99mTc Medronate,99mTc Mertiatide,99mTc Oxidronate,99mTc Pentetate,99mTc Pertechnetate,99mTc Sestamibi,99mTc Sulfur Colloid,99mTc Tetrofosmin, Thallium-201, or Xenon-133. [000282] The reporting agent can also be a dye, e.g., a fluorophore, which is useful in detecting a disease mediated by WT1 / HLA-A2-expressing cells in tissue samples. [000283] To perform a diagnostic assay in vitro, an anti-WT1 / HLA-A2 antibody can be brought in contact with a sample suspected of containing WT1 / HLA-A2, e.g., WT1 / HLA-A2 expressing cells or soluble WT1 / HLA-A2 in disease microenvironment. An antibody and the sample may be incubated under suitable conditions for a suitable period to allow for binding of the antibody to the WT1 / HLA-A2 antigen. Such an interaction can then be detected via routine methods, e.g., ELISA, histological staining or FACS. To perform a diagnostic assay in vivo, a suitable amount of anti-WT1 / HLA-A2 antibodies, conjugated with a label (e.g., an imaging agent or a contrast agent), can be administered to a subject in need of the examination. Presence of the labeled antibody can be detected based on the signal released from the label by routine methods. [000284] To perform scientific research assays, an anti-WT1 / HLA-A2 antibody can be used to study bioactivity of WT1 / HLA-A2, detect the presence of WT1 / HLA-A2 intracellularly, and or regulate the effect of WT1 / HLA-A2. For example, a suitable amount of anti- WT1 / HLA-A2 can be brought in contact with a sample (e.g. a new cell type that is not previously identified as WT1 / HLA-A2 producing cells) suspected of producing WT1 / HLA- A2. The cells are permeabilized prior to contacting the anti-WT1 / HLA-A2 antibody. An antibody and the sample may be incubated under suitable conditions for a suitable period to Docket No. A1361.70020WO00 1410150.1allow for binding of the antibody to the WT1 / HLA-A2 antigen. Such an interaction can then be detected via routine methods, e.g., ELISA, histological staining or FACS. VI. Kits for Therapeutic and Diagnostic Applications [000285] The present disclosure also provides kits for the therapeutic or diagnostic applications as disclosed herein. Such kits can include one or more containers comprising an anti-WT1 / HLA-A2 antibody, e.g., any of those described herein. [000286] In some embodiments, the kit can comprise instructions for use in accordance with any of the methods described herein. The included instructions can comprise a description of administration of the anti-WT1 / HLA-A2 antibody to treat, delay the onset, or alleviate a target disease as those described herein. The kit may further comprise a description of selecting an individual suitable for treatment based on identifying whether that individual has the target disease. In still other embodiments, the instructions comprise a description of administering an antibody to an individual at risk of the target disease. [000287] The instructions relating to the use of an anti-WT1 / HLA-A2 antibody generally include information as to dosage, dosing schedule, and route of administration for the intended treatment. The containers may be unit doses, bulk packages (e.g., multi-dose packages) or sub-unit doses. Instructions supplied in the kits of the invention are typically written instructions on a label or package insert (e.g., a paper sheet included in the kit), but machine-readable instructions (e.g., instructions carried on a magnetic or optical storage disk) are also acceptable. [000288] The label or package insert indicates that the composition is used for treating, delaying the onset and / or alleviating a disease or disorder. Instructions may be provided for practicing any of the methods described herein. [000289] The kits of this invention are in suitable packaging. Suitable packaging includes, but is not limited to, vials, bottles, jars, flexible packaging (e.g., sealed Mylar or plastic bags), and the like. [000290] Also contemplated are packages for use in combination with a specific device, such as an infusion device, such as a minipump. A kit may have a sterile access port (for example the container may be an intravenous solution bag or a vial having a stopper pierceable by a hypodermic injection needle). The container may also have a sterile access port (for example the container may be an intravenous solution bag or a vial having a stopper pierceable by a hypodermic injection needle). At least one active agent in the composition is an anti- Docket No. A1361.70020WO00 1410150.1WT1 / HLA-A2 antibody as those described herein. [000291] Kits may optionally provide additional components such as buffers and interpretive information. Normally, the kit comprises a container and a label or package insert(s) on or associated with the container. In some embodiments, the invention provides articles of manufacture comprising contents of the kits described above. [000292] Also provided herein are kits for use in detecting WT1 / HLA-A2 in a sample. Such a kit may comprise an anti-WT1 / HLA-A2 antibody described herein. In some instances, the anti-WT1 / HLA-A2 antibody can be conjugated with a detectable label as those described herein. As used herein, “conjugated” or “attached” means two entities are associated, preferably with sufficient affinity that the therapeutic / diagnostic benefit of the association between the two entities is realized. The association between the two entities can be either direct or via a linker, such as a polymer linker. Conjugated or attached can include covalent or noncovalent bonding as well as other forms of association, such as entrapment, e.g., of one entity on or within the other, or of either or both entities on or within a third entity, such as a micelle. [000293] Alternatively or in addition, the kit may comprise a secondary antibody capable of binding to anti-WT1 / HLA-A2 antibody. The kit may further comprise instructions for using the anti-WT1 / HLA-A2 antibody for detecting WT1 / HLA-A2. EXAMPLES Example 1. Generation of candidate anti-WT1 / HLA-A2 candidates. [000294] To generate antibodies against WT1 / HLA-A2 (WT1 peptide sequence: RMFPNAPYL (SEQ ID NO: 75)), ATX-Gk™ mice, which produce human antibodies, were immunized subcutaneously with WT1 / HLA-A2 complex carrying an His-tag on a weekly basis. After a total of 5 injections, mice were sacrificed and their splenocytes were used for antigen-specific B cell isolation by fluorescence-assisted cell sorting and to build immune- phage libraries. [000295] For titer measurement, mouse sera were prepared and used in an enzyme-linked immunosorbent assay (ELISA) against WT1 / HLA-A2 protein complex. Briefly, WT1 / HLA- A2 protein complex was coated on an ELISA plate. Plates were blocked with 3% BSA buffer for 1hr and after PBS wash, sera dilutions were transferred to the ELISA plate and incubated for 1hr. After PBS wash, a secondary antibody specific for mouse IgG was added to the ELISA plate for 1 hr. After PBS wash, TMB solution was added, and reaction was then Docket No. A1361.70020WO00 1410150.1stopped using sulfuric acid. [000296] Splenic B cells were stained with a panel of surface marker antibodies and a fluorescently labeled WT1 / HLA-A2 biotinylated using previously published protocols (Tiller et al., J Immunol Methods, 2009. 350(1-2):183-193). WT1 / HLA-A2-specific B cells were sorted one cell per well in lysis buffer and were frozen. Heavy and light chain sequences were retrieved using previously published protocols (Tiller et al., J Immunol Methods, 2009. 350(1-2):183-193; Tiller et al., J Immunol Methods, 2008. 329(1-2):112-124). After sequencing, heavy and light chain genes were cloned into expression vectors. Purified antibodies were tested for binding to WT1 / HLA-A2 monomer and to non-relevant pHLA-A2 monomer. In addition, remaining splenic B cells were used to generate heavy chain and light chain repertoire libraries that will be sequenced using Miseq. Example 2. Binding kinetics of anti-WT1 / HLA-A2 candidates. [000297] Kinetic experiments were performed on Carterra LSA with a running buffer HBSTE, 10mM HEPES pH7.4, 150mM NaCl, 3mM EDTA, 0.05% Tween 20. Antibodies were captured on an anti-human Fc capture chip prepared with a HC30M chip. For kinetics analysis, WT1(RMFPNAPYL (SEQ ID NO: 75) / HLA*02.01 monomer complex at a concentration from 0.076 nM to 1500 nM (a serial 3-fold dilution) was injected sequentially at analyte in the binding kinetics experiment. For each concentration, there was 5 Min association followed by 15 Min dissociation. Results were processed and analyzed in Carterra LSA Kinetics Software. The kinetic data was referenced with the interstitial reference spots and double-referenced to a buffer cycle, and then fit globally to a 1:1 binding model to determine their apparent association and dissociation kinetic rate constants (ka and kd values). The ratio of kd / ka was used to derive the KD value of each antigen / mAb interaction, i.e. KD=kd / ka. Example 3. Cell Binding Assay of anti-WT1 / HLA-A2 candidates. [000298] T2 cells at a concentration of 106cells / mL were incubated with 50 μM peptide of interest or control peptide overnight in serum-free RPMI medium supplemented with 5 mg / mL human b2-microglobulin (Sigma, St. Louis, MO, USA). After the incubation, T2 cell was washed with PBS. In an antibody-cell binding experiment, the antibodies were tested at a concentration from 100 nM to 0.6 pM (a serial 3-fold dilution) for binding on the prepared T2 cells for 45 min at 4°C. Cells were then incubated with the secondary antibody R- Docket No. A1361.70020WO00 1410150.1Phycoerythrin AffiniPure Goat Anti-Human IgG (Jackson Immunoresearch 109-115-098). The data was acquired on FACSCanto II (BD) or on Intellicyt iQue3. Median fluorescence intensities (MFI) were plotted against the concentrations of the antibodies (FIG. 1). EC50 was derived from fitting to 4 parameter dose-response curve. Values are shown in Table E1 below (n.a. = antibody did not reach plateau). Table E1. Binding affinity and kinetics Candidate Ka (1 / Ms) Kd (1 / s) KD (M) EC50 4Example 4. Polyspecificity testing of anti-WT1 / HLA-A2 candidates. [000299] Cells engineered to express anti-WT1 / HLA-A2 antibodies were co-cultured with cancer cell lines either expressing WT1 with HLA-A2 (SKM-1 cells) or cell lines that express WT1 without HLA-A2 (K562 cells) or HLA-A2 without WT1 (T2 cells). Anti-WT1 / HLA- A2 antibodies provided by the present disclosure were found to specifically bind SKM-1 cells at comparable strength to Comparator Antibodies, while they did not bind off-target cell lines K562 or T2 (FIG. 2). Example 5. CAR-T cells expressing an anti-WT1 / HLA-A2 candidate are functional and control tumor growth in immunodeficient mice. [000300] CAR-T cells were either mock transfected or transfected with a construct encoding the anti-WT1 / HLA-A2 #1 antibody. CAR-T cells were then co-cultured in various ratios with Docket No. A1361.70020WO00 1410150.1SKM-1 cells, a leukemic cell line that expresses WT1 / HLA-A2. Anti-WT1 / HLA-A2 antibody-expressing CAR-T cells produced interleukin-2 (IL-2) at all ratios of CAR-T cells:SKM-1 cells (FIG. 3), indicating functional responsiveness to cancer cells in vitro. [000301] To determine the functionality of CAR-T cells expressing an anti-WT1 / HLA-A2 antibody, immunodeficient NOD scid gamma (NSG) were injected in the flank with BV-173 human B cell leukemia cells. BV-173 cells were co-injected with either mock transfected CAR-T cells or CAR-T cells expressing an anti-WT1 / HLA-A2 antibody (e.g., anti- WT1 / HLA-A2 #1). Tumor size was measured using calipers at days 8, 15, 22, and 29 post- injection. Mice receiving CAR-T cells expressing an anti-WT1 / HLA-A2 antibody had markedly reduced tumor growth compared to mice that did not receive any CAR-T cells (FIG. 4). Example 6. Functional testing of anti-WT1 / HLA-A2 candidate activity in human tissue [000302] Bispecific antibodies containing anti-WT1 / HLA-A2 binding arms engineered in an anti-CD3-containing format will be tested in co-culture assays using Jurkat NFAT-luciferase reporter cells co-cultured with T2 accessory cells pulsed with target (WT1-SLL) or irrelevant (WT1-VLD) peptides. Human PBMCs from several unique HLA-A*02.01 donors will be acquired and CD8+ T cells will be isolated and cryopreserved. These CD8+ T cells will be co-cultured with a variety of human tumor cell lines, including controls which are WT1-SLL positive or negative, and controls which are HLA-A*02.01 positive or negative. Functional readouts will include: target cell cytotoxicity (measured by live-cell imaging and / or flow cytometry), cytokine production from the co-culture supernatant (measured by multiplexed electrochemiluminescence ELISA). Additionally, bulk PBMCs from several unique HLA- A*02.01 donors will be co-cultured with a variety of human tumor cell lines, including controls which are WT1-SLL positive or negative, and controls which are HLA-A*02.01 positive or negative. Functional readouts will include: target cell cytotoxicity (measured by flow cytometry), immunoprofiling including T-cell activation / exhaustion (measured by flow cytometry). Example 7. Toxicity and Tissue reactivity of anti-WT1 / HLA-A2 candidate activity. [000303] Bispecific antibodies containing anti-WT1 / HLA-A2 binding arms engineered in an anti-CD3-containing format will be incubated with whole blood from several unique human donors to quantify whether there is CD3-dependent cytokine release, indicative of potential Docket No. A1361.70020WO00 1410150.1clinical toxicities. Additionally, a variety of normal human tissues and normal human cells lines (i.e., not cancer cell lines) will be procured and bispecific antibodies will be assessed for off-target binding to any proteins or HLA / peptide complexes present in normal healthy human tissue. OTHER EMBODIMENTS [000304] All of the features disclosed in this specification may be combined in any combination. Each feature disclosed in this specification may be replaced by an alternative feature serving the same, equivalent, or similar purpose. Thus, unless expressly stated otherwise, each feature disclosed is only an example of a generic series of equivalent or similar features. [000305] From the above description, one skilled in the art can easily ascertain the essential characteristics of the present invention, and without departing from the spirit and scope thereof, can make various changes and modifications of the invention to adapt it to various usages and conditions. Thus, other embodiments are also set forth as follows: EQUIVALENTS AND SCOPE [000306] In the claims, articles such as “a,” “an,” and “the” may mean one or more than one unless indicated to the contrary or otherwise evident from the context. Claims or descriptions that include “or” between one or more members of a group are considered satisfied if one, more than one, or all of the group members are present in, employed in, or otherwise relevant to a given product or process unless indicated to the contrary or otherwise evident from the context. The invention includes embodiments in which exactly one member of the group is present in, employed in, or otherwise relevant to a given product or process. The invention includes embodiments in which more than one, or all of the group members are present in, employed in, or otherwise relevant to a given product or process. [000307] Furthermore, the invention encompasses all variations, combinations, and permutations in which one or more limitations, elements, clauses, and descriptive terms from one or more of the listed claims is introduced into another claim. For example, any claim that is dependent on another claim can be modified to include one or more limitations found in any other claim that is dependent on the same base claim. Where elements are presented as lists, e.g., in Markush group format, each subgroup of the elements is also disclosed, and any element(s) can be removed from the group. It should be understood that, in general, where the Docket No. A1361.70020WO00 1410150.1invention, or aspects of the invention, is / are referred to as comprising particular elements and / or features, certain embodiments of the invention or aspects of the invention consist, or consist essentially of, such elements and / or features. For purposes of simplicity, those embodiments have not been specifically set forth in haec verba herein. [000308] The phrase “and / or,” as used herein in the specification and in the claims, should be understood to mean “either or both” of the elements so conjoined, i.e., elements that are conjunctively present in some cases and disjunctively present in other cases. Multiple elements listed with “and / or” should be construed in the same fashion, i.e., “one or more” of the elements so conjoined. Other elements may optionally be present other than the elements specifically identified by the “and / or” clause, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, a reference to “A and / or B”, when used in conjunction with open-ended language such as “comprising” can refer, in one embodiment, to A only (optionally including elements other than B); in another embodiment, to B only (optionally including elements other than A); in yet another embodiment, to both A and B (optionally including other elements); etc. [000309] As used herein in the specification and in the claims, “or” should be understood to have the same meaning as “and / or” as defined above. For example, when separating items in a list, “or” or “and / or” shall be interpreted as being inclusive, i.e., the inclusion of at least one, but also including more than one, of a number or list of elements, and, optionally, additional unlisted items. Only terms clearly indicated to the contrary, such as “only one of” or “exactly one of,” or, when used in the claims, “consisting of,” will refer to the inclusion of exactly one element of a number or list of elements. In general, the term “or” as used herein shall only be interpreted as indicating exclusive alternatives (i.e. “one or the other but not both”) when preceded by terms of exclusivity, such as “either,” “one of,” “only one of,” or “exactly one of.” “Consisting essentially of,” when used in the claims, shall have its ordinary meaning as used in the field of patent law. [000310] As used herein in the specification and in the claims, the phrase “at least one,” in reference to a list of one or more elements, should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including at least one of each and every element specifically listed within the list of elements and not excluding any combinations of elements in the list of elements. This definition also allows that elements may optionally be present other than the elements specifically identified within the list of elements to which the phrase “at least one” refers, whether related or Docket No. A1361.70020WO00 1410150.1unrelated to those elements specifically identified. Thus, as a non-limiting example, “at least one of A and B” (or, equivalently, “at least one of A or B,” or, equivalently “at least one of A and / or B”) can refer, in one embodiment, to at least one, optionally including more than one, A, with no B present (and optionally including elements other than B); in another embodiment, to at least one, optionally including more than one, B, with no A present (and optionally including elements other than A); in yet another embodiment, to at least one, optionally including more than one, A, and at least one, optionally including more than one, B (and optionally including other elements); etc. [000311] It should also be understood that, unless clearly indicated to the contrary, in any methods claimed herein that include more than one step or act, the order of the steps or acts of the method is not necessarily limited to the order in which the steps or acts of the method are recited. [000312] In the claims, as well as in the specification above, all transitional phrases such as “comprising,” “including,” “carrying,” “having,” “containing,” “involving,” “holding,” “composed of,” and the like are to be understood to be open-ended, i.e., to mean including but not limited to. Only the transitional phrases “consisting of” and “consisting essentially of” shall be closed or semi-closed transitional phrases, respectively, as set forth in the United States Patent Office Manual of Patent Examining Procedures, Section 2111.03. It should be appreciated that embodiments described in this document using an open-ended transitional phrase (e.g., “comprising”) are also contemplated, in alternative embodiments, as “consisting of” and “consisting essentially of” the feature described by the open-ended transitional phrase. For example, if the application describes “a composition comprising A and B,” the application also contemplates the alternative embodiments “a composition consisting of A and B” and “a composition consisting essentially of A and B.” [000313] Where ranges are given, endpoints are included. Furthermore, unless otherwise indicated or otherwise evident from the context and understanding of one of ordinary skill in the art, values that are expressed as ranges can assume any specific value or sub-range within the stated ranges in different embodiments of the invention, to the tenth of the unit of the lower limit of the range, unless the context clearly dictates otherwise. [000314] This application refers to various issued patents, published patent applications, journal articles, and other publications, all of which are incorporated herein by reference. If there is a conflict between any of the incorporated references and the instant specification, the specification shall control. In addition, any particular embodiment of the present invention Docket No. A1361.70020WO00 1410150.1that falls within the prior art may be explicitly excluded from any one or more of the claims. Because such embodiments are deemed to be known to one of ordinary skill in the art, they may be excluded even if the exclusion is not set forth explicitly herein. Any particular embodiment of the invention can be excluded from any claim, for any reason, whether or not related to the existence of prior art. [000315] Those skilled in the art will recognize or be able to ascertain using no more than routine experimentation many equivalents to the specific embodiments described herein. The scope of the present embodiments described herein is not intended to be limited to the above Description, but rather is as set forth in the appended claims. Those of ordinary skill in the art will appreciate that various changes and modifications to this description may be made without departing from the spirit or scope of the present invention, as defined in the following claims. [000316] The recitation of a listing of chemical groups in any definition of a variable herein includes definitions of that variable as any single group or combination of listed groups. The recitation of an embodiment for a variable herein includes that embodiment as any single embodiment or in combination with any other embodiments or portions thereof. The recitation of an embodiment herein includes that embodiment as any single embodiment or in combination with any other embodiments or portions thereof. Docket No. A1361.70020WO00 1410150.1

Claims

1. CLAIMS What is claimed is:

1. An antibody that binds Wilms’ tumor 1 protein / HLA-A2 complex (WT1 / HLA-A2) comprising: a heavy chain complementarity determining region 1 (HC CDR1) comprising the amino acid sequence X1X2X3X4X5X6X7, wherein: X1 is S, R, or absent, X2 is S, G, or absent, X3is G or D, X4is Y or S, X5 is Y or A, X6 is W or M, and / or X7is G, S, or H; a heavy chain complementarity determining region 2 (HC CDR2) comprising the amino acid sequence X1X2X3X4X5X6X7X8X9YX11X12SX14X15KX17, wherein: X1is Y, G, or absent, X2 is S, E, or I, X3 is I, F, or S, X4is Y, S, or W, X5is Y, H, F, or N, X6 is S or G, X7 is G or S, X8is S, T, or N, X9 is Y, N, or G, X11 is N or A, X12is P or D, X14 is S or L, X15 is L or V, and / or X17is S or G; and a heavy chain complementarity determining region 3 (HC CDR3) comprising the amino acid sequence X1X2X3X4X5WX7X8X9X10X11X12, wherein:; X1 is D or absent, Docket No. A1361.70020WO00 1410150.1 X2is H, P, or N, X3 is E, I, or F, X4 is P, Q, or F, X5is Y, L, or E, X7 is Y, F, or W, X8 is F, D, or G, X9is D, Y, or T, X10 L, F, or absent, X11 is D or absent, and / or X12is H, Y, or absent; anda light chain complementarity determining region 1 (LC CDR1) comprising the amino acid sequence RASQX5ISX8X9LX11 (SEQ ID NO: 105), wherein X5 is D or G, X8is N or S, X9 is Y or W, and / or X11 is A or T; and a light chain complementarity determining region 2 (LC CDR2) comprising the amino acid sequence AASX4X5X6S (SEQ ID NO: 106), wherein: X4 is S or T, X5is L or S, and / or X6is Q or E; and a light chain complementarity determining region 3 (LC CDR3) comprising the amino acid sequence X1X2X3X4X5X6PX8X9, wherein: X1is L or Q, X2 is Q or H, X3 is H, Y, or A, X4is N or R, X5 is S, N, or T, X6 is Y, L, or F, X7is P, X8is R, L, or F; and / or X9 is T. Docket No. A1361.70020WO00 1410150.

12. An antibody that binds Wilms’ tumor 1 protein / HLA-A2 complex (WT1 / HLA-A2) comprising: a heavy chain complementarity determining region 1 (HC CDR1) comprising the amino acid sequence X1X2GYYWX3(SEQ ID NO: 59), wherein: X1 is S, T, N, Q, R, K, or absent, X2 is S, T, N, Q, G, or absent, and / or X3is S, T, N, Q, or G; and a heavy chain complementarity determining region 2 (HC CDR2) comprising the amino acid sequence X4X5YX6SGX7TX8YNPSLKS (SEQ ID NO: 60), wherein: X4is S, T, N, Q, E, or D, X5is I, V, L, A, Y, W, or F, X6 is Y, W, H, or F, X7 is S, T, Q, or N, and / or X8is Y, W, F, S, T, Q, or N; and a heavy chain complementarity determining region 3 (HC CDR3) comprising the amino acid sequence HEPYWYFDL (SEQ ID NO: 3); and a light chain complementarity determining region 1 (LC CDR1) comprising the amino acid sequence RASQDISNYLX9 (SEQ ID NO: 61), wherein X9 is A, I, V, L, S, N, Q, or T; and a light chain complementarity determining region 2 (LC CDR2) comprising the amino acid sequence AASX10LX11S (SEQ ID NO: 62), wherein: X10 is S, T, N, or Q, and / or X11 is S, T, N, Q, D, or E; and a light chain complementarity determining region 3 (LC CDR3) comprising the amino acid sequence X12X13X14X15X16X17PX18T, wherein: X12 is A, I, V, L, S, N, T, or Q, X13is S, N, T, Q or H, X14 is H, F, W or Y, X15 is S, T, Q, N, K, or R, X16is S, Q, N, or T, X17is Y, F, W, A, V, I or L, and / or X18 is K, R, A, V, I, or L. Docket No. A1361.70020WO00 1410150.

13. The antibody of claim 2, wherein X1 is S, R, or absent, X2 is S, G, or absent, X3is S or G, X4 is S or E, X5 is I or F, X6is Y, H, or F, X7 is S, T, or N, X8 is Y or N, X10is S or T, X11is Q or E, X12 is L or Q, X13 is Q or H, X14is H or Y, X15 is N or R, X16 is S, N, or T, X17is Y or L, and / or X18 is R or L.

4. An antibody that binds Wilms’ tumor 1 protein / HLA-A2 complex (WT1 / HLA-A2) comprising: a heavy chain complementarity determining region 1 (HC CDR1) comprising the amino acid sequence GYYW (SEQ ID NO: 9), a heavy chain complementarity determining region 2 (HC CDR2) comprising the amino acid sequence YNPSLKS (SEQ ID NO: 10), a heavy chain complementarity determining region 3 (HC CDR3) comprising the amino acid sequence HEPYWYFDL (SEQ ID NO: 3); and a light chain complementarity determining region 1 (LC CDR1) comprising the amino acid sequence RASQDISNYL (SEQ ID NO: 16); and a light chain complementarity determining region 2 (LC CDR2) comprising the amino acid sequence AASX10LX11S (SEQ ID NO: 62), wherein: X10is S, T, N, or Q, X11 is S, T, N, Q, D, or E; and Docket No. A1361.70020WO00 1410150.1a light chain complementarity determining region 3 (LC CDR3) comprising the amino acid sequence X12X13X14X15X16X17PX18T, wherein: X12 is A, I, V, L, S, N, T, or Q, X13is S, N, T, Q or H, X14 is H, F, W or Y, X15 is S, T, Q, N, K, or R, X16is S, Q, N, or T, X17 is Y, F, W, A, V, I or L, X18 is K, R, A, V, I, or L.

5. An antibody that binds Wilms’ tumor 1 protein / HLA-A2 complex (WT1 / HLA-A2) comprising: a heavy chain complementarity determining region 1 (HC CDR1) comprising the amino acid sequence DYAMH (SEQ ID NO: 85); and a heavy chain complementarity determining region 2 (HC CDR2) comprising the amino acid sequence GISWNSGNX1GYADSVKG (SEQ ID NO: 95), wherein X1 is A, L, V or I; and a heavy chain complementarity determining region 3 (HC CDR3) comprising the amino acid sequence DNFFEWWGTFDX2 (SEQ ID NO: 96), wherein X2 is F, W, H or Y; and a light chain complementarity determining region 1 (LC CDR1) comprising the amino acid sequence RASQGISNYLA (SEQ ID NO: 88); and a light chain complementarity determining region 2 (LC CDR2) comprising the amino acid sequence AASSX3QS (SEQ ID NO: 97), wherein X3is A, V, I, L, T, N, Q, or S; and a light chain complementarity determining region 3 (LC CDR3) comprising the amino acid sequence QQYNX4YPFT (SEQ ID NO: 98), wherein X4 is T, Q, N or S.

6. The antibody of claim 5, wherein X1 is V or I; X2is H or Y; X3is L or S; and / or X4 is N or S. Docket No. A1361.70020WO00 1410150.

17. The antibody of any one of claims 1-6, wherein the antibody comprises: (a) a HC CDR1, a HC CDR2, and a HC CDR3 of a heavy chain variable region (VH) comprising the amino acid sequence of SEQ ID NO: 7, and a LC CDR1, a LC CDR2, and a LC CDR3 of a light chain variable region (VL) comprising the amino acid sequence of SEQ ID NO: 8; (b) a HC CDR1, a HC CDR2, and a HC CDR3 of a VH comprising the amino acid sequence of SEQ ID NO: 14; and a LC CDR1, LC CDR2, and LC CDR3 of a VL comprising the amino acid sequence of SEQ ID NO: 15; (c) a HC CDR1, a HC CDR2, and a HC CDR3 of a VH comprising the amino acid sequence of SEQ ID NO: 23; and a LC CDR1, LC CDR2, and LC CDR3 of a VL comprising the amino acid sequence of SEQ ID NO: 24; (d) a HC CDR1, a HC CDR2, and a HC CDR3 of a VH comprising the amino acid sequence of SEQ ID NO: 29; and a LC CDR1, LC CDR2, and LC CDR3 of a VL comprising the amino acid sequence of SEQ ID NO: 30; or (e) a HC CDR1, a HC CDR2, and a HC CDR3 of a VH comprising the amino acid sequence of SEQ ID NO: 35; and a LC CDR1, LC CDR2, and LC CDR3 of a VL comprising the amino acid sequence of SEQ ID NO: 36 (f) a HC CDR1, a HC CDR2, and a HC CDR3 of a heavy chain variable region (VH) comprising the amino acid sequence of SEQ ID NO: 83, and a LC CDR1, a LC CDR2, and a LC CDR3 of a light chain variable region (VL) comprising the amino acid sequence of SEQ ID NO: 84; (g) a HC CDR1, a HC CDR2, and a HC CDR3 of a heavy chain variable region (VH) comprising the amino acid sequence of SEQ ID NO: 90, and a LC CDR1, a LC CDR2, and a LC CDR3 of a light chain variable region (VL) comprising the amino acid sequence of SEQ ID NO: 91; and (h) a HC CDR1, a HC CDR2, and a HC CDR3 of a heavy chain variable region (VH) comprising the amino acid sequence of SEQ ID NO: 93, and a LC CDR1, a LC CDR2, and a LC CDR3 of a light chain variable region (VL) comprising the amino acid sequence of SEQ ID NO:

94.

8. The antibody of any one of the preceding claims, wherein the antibody comprises: (a) a HC CDR1 comprising the amino acid sequence of SEQ ID NO: 1, a HC CDR2 comprising the amino acid sequence of SEQ ID NO: 2, a HC CDR3 comprising the Docket No. A1361.70020WO00 1410150.1amino acid sequence of SEQ ID NO: 3, a LC CDR1 comprising the amino acid sequence of SEQ ID NO: 4, a LC CDR2 comprising the amino acid sequence of SEQ ID NO: 5, and a LC CDR3 comprising the amino acid sequence of SEQ ID NO: 6; (b) a HC CDR1 comprising the amino acid sequence of SEQ ID NO: 11, a HC CDR2 comprising the amino acid sequence of SEQ ID NO: 12, a HC CDR3 comprising the amino acid sequence of SEQ ID NO: 3, a LC CDR1 comprising the amino acid sequence of SEQ ID NO: 4, a LC CDR2 comprising the amino acid sequence of SEQ ID NO: 5, and a LC CDR3 comprising the amino acid sequence of SEQ ID NO: 13; (c) a HC CDR1 comprising the amino acid sequence of SEQ ID NO: 18, a HC CDR2 comprising the amino acid sequence of SEQ ID NO: 19, a HC CDR3 comprising the amino acid sequence of SEQ ID NO: 3, a LC CDR1 comprising the amino acid sequence of SEQ ID NO: 20, a LC CDR2 comprising the amino acid sequence of SEQ ID NO: 21, and a LC CDR3 comprising the amino acid sequence of SEQ ID NO: 22; (d) a HC CDR1 comprising the amino acid sequence of SEQ ID NO: 27, a HC CDR2 comprising the amino acid sequence of SEQ ID NO: 12, a HC CDR3 comprising the amino acid sequence of SEQ ID NO: 3, a LC CDR1 comprising the amino acid sequence of SEQ ID NO: 4, a LC CDR2 comprising the amino acid sequence of SEQ ID NO: 5, and a LC CDR3 comprising the amino acid sequence of SEQ ID NO: 28; or (e) a HC CDR1 comprising the amino acid sequence of SEQ ID NO: 1, a HC CDR2 comprising the amino acid sequence of SEQ ID NO: 33, a HC CDR3 comprising the amino acid sequence of SEQ ID NO: 3, a LC CDR1 comprising the amino acid sequence of SEQ ID NO: 20, a LC CDR2 comprising the amino acid sequence of SEQ ID NO: 21, and a LC CDR3 comprising the amino acid sequence of SEQ ID NO: 34; (f) a HC CDR1 comprising the amino acid sequence of SEQ ID NO: 78, a HC CDR2 comprising the amino acid sequence of SEQ ID NO: 79, a HC CDR3 comprising the amino acid sequence of SEQ ID NO: 80, a LC CDR1 comprising the amino acid sequence of SEQ ID NO: 81, a LC CDR2 comprising the amino acid sequence of SEQ ID NO: 5, and a LC CDR3 comprising the amino acid sequence of SEQ ID NO: 82; (g) a HC CDR1 comprising the amino acid sequence of SEQ ID NO: 85, a HC CDR2 comprising the amino acid sequence of SEQ ID NO: 86, a HC CDR3 comprising the amino acid sequence of SEQ ID NO: 87, a LC CDR1 comprising the amino acid sequence of SEQ ID NO: 88, a LC CDR2 comprising the amino acid sequence of SEQ ID NO: 5, and a LC CDR3 comprising the amino acid sequence of SEQ ID NO: 89; or Docket No. A1361.70020WO00 1410150.1(h) a HC CDR1 comprising the amino acid sequence of SEQ ID NO: 85, a HC CDR2 comprising the amino acid sequence of SEQ ID NO: 86, a HC CDR3 comprising the amino acid sequence of SEQ ID NO: 87, a LC CDR1 comprising the amino acid sequence of SEQ ID NO: 88, a LC CDR2 comprising the amino acid sequence of SEQ ID NO: 89, and a LC CDR3 comprising the amino acid sequence of SEQ ID NO:

92.

9. The antibody of any one of the preceding claims, wherein the antibody comprises: (a) a VH comprising the amino acid of SEQ ID NO: 7, and / or a VL comprising the amino acid sequence of SEQ ID NO: 8; (b) a VH comprising the amino acid of SEQ ID NO: 14, and / or a VL comprising the amino acid sequence of SEQ ID NO: 15; (c) a VH comprising the amino acid of SEQ ID NO: 23, and / or a VL comprising the amino acid sequence of SEQ ID NO: 24; (d) a VH comprising the amino acid of SEQ ID NO: 29, and / or a VL comprising the amino acid sequence of SEQ ID NO: 30; (e) a VH comprising the amino acid of SEQ ID NO: 35, and / or a VL comprising the amino acid sequence of SEQ ID NO: 36; (f) a VH comprising the amino acid of SEQ ID NO: 83, and / or a VL comprising the amino acid sequence of SEQ ID NO: 84; (g) a VH comprising the amino acid of SEQ ID NO: 90, and / or a VL comprising the amino acid sequence of SEQ ID NO: 91; or (h) a VH comprising the amino acid of SEQ ID NO: 93, and / or a VL comprising the amino acid sequence of SEQ ID NO:

94.

10. The antibody of any one of the preceding claims, wherein the antibody is a full-length IgG, a Fab fragment, a F(ab') fragment, a F(ab’)2 fragment, a scFv, or a Fv.

11. The antibody of any one of the preceding claims, wherein the antibody comprises a heavy chain constant region of the isotype IgG1, IgG2, IgG3, or IgG4.

12. An antibody that specifically binds an epitope of a WT1 peptide that is complexed with a single chain HLA-A2 molecule, wherein the WT1 peptide comprises the amino acid Docket No. A1361.70020WO00 1410150.1sequence RMFPNAPYL (SEQ ID NO: 75), wherein the antibody does not specifically bind to: (i) a MED13L peptide that is complexed with the single chain HLA-A2 molecule, wherein the MED13L peptide comprising the amino acid sequence RMFPTPPSL (SEQ ID NO: 76); and (ii) a PIGQ peptide that is complexed with the single chain HLA-A2 molecule, wherein the PIGQ peptide comprises the amino acid sequence RMFPGEVAL (SEQ ID NO: 77).

13. The antibody of claim 12, wherein the antibody is obtained by a process comprising: (1) exposing a single-chain HLA-A2 molecule in complex with the WT1 peptide to a library of antibodies under conditions in which antibodies of the library detectably bind to the single-chain HLA-A2 molecule in complex with the WT1 peptide; (2) obtaining the sequences of a heavy chain variable domain of at least one of the detectably binding antibodies of step (1); and (3) producing an antibody having at least a heavy chain complementarity determining region 3 (HC CDR3) of the heavy chain variable domain of step (2), thereby obtaining the antibody that specifically binds the WT1 peptide complexed with an HLA.

14. The antibody of claim 13, wherein the process further comprises: (i) exposing the antibody obtained in step (3) to a MED13L peptide that is complexed with the single chain HLA-A2 molecule; (ii) determining that the antibody does not specifically bind to the MED13L peptide that is complexed with the single chain HLA-A2 molecule.

15. A chimeric antigen receptor (CAR) comprising the antibody of any one of the preceding claims.

16. The CAR of claim 15, wherein the CAR further comprises a hinge region.

17. The CAR of claim 15 or claim 16, wherein the CAR further comprises a transmembrane domain. Docket No. A1361.70020WO00 1410150.

118. The CAR of any one of claims 15-17, wherein the CAR further comprises an intracellular domain.

19. The CAR of any one of claims 15-18, wherein the CAR further comprises a co- stimulatory domain.

20. An isolated nucleic acid encoding the VH and / or VL of the antibody of any one of claims 1-14, or the CAR of any one of claims 15-19.

21. The isolated nucleic acid of claim 17, wherein the isolated nucleic acid comprises: (a) the nucleic acid sequence of SEQ ID NO: 39, and / or the nucleic acid sequence of SEQ ID NO: 40; (b) the nucleic acid sequence of SEQ ID NO: 43, and / or the nucleic acid sequence of SEQ ID NO: 44; (c) the nucleic acid sequence of SEQ ID NO: 47, and / or the nucleic acid sequence of SEQ ID NO: 48; (d) the nucleic acid sequence of SEQ ID NO: 51, and / or the nucleic acid sequence of SEQ ID NO: 52; (e) the nucleic acid sequence of SEQ ID NO: 55, and / or the nucleic acid sequence of SEQ ID NO: 56; (f) the nucleic acid sequence of SEQ ID NO: 99, and / or the nucleic acid sequence of SEQ ID NO: 100; (g) the nucleic acid sequence of SEQ ID NO: 101, and / or the nucleic acid sequence of SEQ ID NO: 102; and / or (h) the nucleic acid sequence of SEQ ID NO: 103, and / or the nucleic acid sequence of SEQ ID NO:

104.

22. An expression vector comprising the isolated nucleic acid of claim 20 or 21.

23. A host cell comprising the antibody of any one of claims 1-14, the CAR of any one of claims 15-19, the isolated nucleic acid of claim 20 or 21, or the vector of claim 22. Docket No. A1361.70020WO00 1410150.

124. An engineered cell expressing the antibody of any one of claims 1-14 or the CAR of any one of claims 15-19.

25. The engineered cell of claim 24, wherein the engineered cell is a T cell, a NK cell, or a NKT cell.

26. A composition comprising the antibody of any one of claims 1-14, the CAR of any one of claims 15-19, the isolated nucleic acid of claims 20 or 21, the vector of claim 22, the host cell of claim 23, or the engineered cell of claim 24 or 25.

27. The composition of claim 26, further comprising a pharmaceutically acceptable carrier.

28. A bispecific antibody comprising a first antigen binding site comprising the antibody of any one of claims 1-14, and a second antigen binding site.

29. The bispecific antibody of claim 28, wherein the second antigen binding site specifically binds to a T cell antigen.

30. The bispecific antibody of claim 28, wherein the T cell antigen is a CD3 complex.

31. The bispecific antibody of claim 28, wherein the second antigen binding site specifically binds to CD3δ of the CD3 complex.

32. The bispecific antibody of claim 30, wherein the second antigen binding site specifically binds to CD3ε of the CD3 complex.

33. The bispecific antibody of claim 30, wherein the second antigen binding site specifically binds to CDγ of the CD3 complex.

34. The bispecific antibody of claim 30, wherein the second antigen binding site binds to a CD3ε / δ heterodimer of the CD3 complex. Docket No. A1361.70020WO00 1410150.

135. The bispecific antibody of claim 30, wherein the second antigen binding site binds to a CD3ε / γ heterodimer of the CD3 complex.

36. The bispecific antibody of any one of claims 28-35, wherein the bispecific antibody comprises a first arm that is configured as a Fab, a Fab’, or a scFv and that comprises the first antigen binding site.

37. The bispecific antibody of any one of claims 28-35, wherein the bispecific antibody comprises a second arm that is configured as a Fab, a Fab’, or a scFv and that comprises the second antigen binding site.

38. The bispecific antibody of any one of claims 28-35, wherein the bispecific antibody comprise a first arm that is configured as a Fab and a second arm that is configured as a scFv.

39. The bispecific antibody of any one of claims 28-35, wherein the bispecific antibody comprises a first arm that is configured as a scFv, and a second arm that is configured as a Fab.

40. The bispecific antibody of any one of claims 28-39, wherein the ratio between the first antigen binding site and the second antigen binding site is 1:1, 1:2, 1:3, 2:1 or 3:

1.

41. A host cell comprising the bispecific antibody of any one of claims 28-40.

42. An engineered cell comprising the bispecific antibody of any one of claims 28-40.

43. A composition comprising the bispecific antibody of any one of claims 28-40.

44. The composition of claim 43, further comprising a pharmaceutically acceptable carrier.

45. A method of treating cancer, the method comprising administering to a subject in need thereof an effective amount of the antibody of any one of claims 1-14, the engineered cell of Docket No. A1361.70020WO00 1410150.1claim 24, 25, or 42, the composition of any one of claims 26, 27, 43, or 44,, or the bispecific antibody of any one of claims 28-44. Docket No. A1361.70020WO00 1410150.1

Images