Anti- CD79b antibody-drug conjugates

Abstract

To provide anti- CD79b antibodies for treating B-cell malignancies and anti- CD79b antibody-drug conjugates comprising the same.SOLUTION: Anti- Ab1 antibody-drug conjugates (ADCs) of the following structure are provided: [n: an integer from 1 to 8; CD79b: CD79b antibodies].SELECTED DRAWING: None

Description

[Technical Field]

[0001] This application claims priority to and the benefit of U.S. Provisional Application No. 63 / 663,844, filed June 25, 2024, the contents of which are incorporated herein by reference in their entirety.

[0002] Sequence Listing This application contains a Sequence Listing that has been submitted electronically in XML format and is incorporated herein by reference in its entirety. The XML copy, created on June 24, 2025, is named ABV21655WOO1_ST26.xml and is 158,263 bytes in size.

[0003] The present disclosure relates to anti-CD79b antibodies and anti-CD79b Top1i antibody drug conjugates (anti-CD79b Top1i ADCs) comprising an anti-CD79b antibody and a topoisomerase 1 inhibitor (Top1i) drug. [Background technology]

[0004] CD79b is overexpressed in most newly diagnosed B-cell non-Hodgkin's lymphomas (B-NHL). CD79 is a heterodimeric protein containing two transmembrane subunits, CD79a and CD79b. The B-cell receptor (BCR) transduces intracellular signals via the CD79a-CD79b heterodimer and BCR-derived signals, which can sustain the growth and survival of malignant B cells. CD79b is part of the signaling components of the BCR and is expressed in almost all major subtypes of B-NHL. It is rapidly transported to lysosomes via major histocompatibility complex (MCH) class II antigen presentation, making it an attractive antibody-drug conjugate (ADC) target.

[0005] ADCs represent a class of therapeutic agents comprising antibodies conjugated via a chemical linker to a cytotoxic drug, often referred to as a "payload." The therapeutic concept of ADCs is to combine the binding capacity of an antibody with a cytotoxic drug for targeted delivery of the cytotoxic drug to tumor cells. This is achieved by binding of the antibody portion of the ADC to target surface antigens, including target surface antigens that are overexpressed or amplified on tumor cells. Summary of the Invention [Problem to be solved by the invention]

[0006] There remains a need in the art to develop potent anti-CD79b Top1i ADCs that provide targeted delivery in treating B-cell malignancies. [Means for solving the problem]

[0007] (Abstract) The present disclosure provides anti-CD79b antibodies, and anti-CD79b Top1i ADCs comprising the anti-CD79b antibodies, which further comprise a Top1i drug as a payload.

[0008] As described further below in this disclosure, embodiments of the anti-CD79b Top1i ADCs disclosed herein have potent antiproliferative and cytotoxic activity against a variety of B-cell malignant cell lines.

[0009] In a first aspect, the present disclosure provides a compound having the following structure:

[0010] [ka] (wherein n is an integer of 1 to 8, Ab1 is an anti-CD79b antibody comprising a heavy chain variable region comprising VH-CDR1, VH-CDR2, and VH-CDR3; and a light chain variable region comprising VL-CDR1, VL-CDR2, and VL-CDR3; VH-CDR1 has the amino acid sequence of SEQ ID NO: 1; VH-CDR2 has the amino acid sequence of SEQ ID NO: 2; VH-CDR3 has the amino acid sequence of SEQ ID NO: 3; VL-CDR1 has the amino acid sequence of SEQ ID NO: 4; VL-CDR2 has the amino acid sequence of SEQ ID NO:5; and VL-CDR3 has the amino acid sequence of SEQ ID NO: 6 The present invention provides an anti-CD79b Top1i ADC.

[0011] A second embodiment includes the anti-CD79b ADC of the first embodiment, wherein Ab1 is of the IgG1 isotype and comprises a heavy chain variable region having the amino acid sequence of SEQ ID NO:7; and a light chain variable region having the amino acid sequence of SEQ ID NO:8.

[0012] A third aspect includes the anti-CD79b ADC of the first aspect, wherein Ab1 is of the IgG1 isotype and comprises a heavy chain having the amino acid sequence of SEQ ID NO:9 or SEQ ID NO:13; and a light chain having the amino acid sequence of SEQ ID NO:10.

[0013] A fourth aspect includes the anti-CD79b ADC of the third aspect, wherein Ab1 comprises a heavy chain having the amino acid sequence of SEQ ID NO: 13; and a light chain having the amino acid sequence of SEQ ID NO: 10.

[0014] A fifth embodiment includes the anti-CD79b ADC of the fourth embodiment, wherein n is 6.

[0015] A sixth aspect includes the anti-CD79b ADC of the third aspect, wherein Ab1 comprises a heavy chain having the amino acid sequence of SEQ ID NO:9; and a light chain having the amino acid sequence of SEQ ID NO:10.

[0016] A seventh embodiment includes the anti-CD79b ADC of the sixth embodiment, wherein n is 6.

[0017] An eighth aspect includes the anti-CD79b ADC of the first or second aspect, wherein the anti-CD79b antibody comprises two identical heavy chains and two identical light chains, each heavy chain comprising the amino acid sequence of SEQ ID NO:9 or SEQ ID NO:13; and each light chain comprising the amino acid sequence of SEQ ID NO:10.

[0018] A ninth aspect includes the anti-CD79b ADC of the first or second aspect, wherein the anti-CD79b antibody comprises a human kappa light chain constant region.

[0019] A tenth aspect includes a pharmaceutical composition comprising the anti-CD79b ADC of any one of the first to ninth aspects and a pharmaceutically acceptable carrier.

[0020] An eleventh aspect includes a method of treating a disease, the method comprising administering to a patient in need thereof an anti-CD79b ADC of any one of the first to ninth aspects.

[0021] A twelfth aspect includes an antibody that specifically binds to human CD79b, the antibody comprising: a heavy chain variable region comprising the amino acid sequence of SEQ ID NO:7; and a light chain variable region comprising the amino acid sequence of SEQ ID NO:8.

[0022] A thirteenth aspect comprises the antibody of the twelfth aspect, wherein the antibody is of the IgG1 isotype, VH-CDR1 comprises the amino acid sequence of SEQ ID NO: 1, VH-CDR2 comprises the amino acid sequence of SEQ ID NO: 2, VH-CDR3 comprises the amino acid sequence of SEQ ID NO: 3, VL-CDR1 comprises the amino acid sequence of SEQ ID NO: 4, VL-CDR2 comprises the amino acid sequence of SEQ ID NO: 5, and VL-CDR3 comprises the amino acid sequence of SEQ ID NO: 6.

[0023] A fourteenth aspect includes the antibody of the twelfth or thirteenth aspect, wherein the antibody comprises a human kappa light chain constant region.

[0024] The fifteenth aspect includes the antibody of any one of the twelfth to fourteenth aspects, wherein the antibody comprises a heavy chain variable region comprising the amino acid sequence of SEQ ID NO:7 and a light chain variable region comprising the amino acid sequence of SEQ ID NO:8.

[0025] A sixteenth aspect includes the antibody of any one of the twelfth to fifteenth aspects, wherein the antibody comprises a heavy chain comprising the amino acid sequence of SEQ ID NO:9 or SEQ ID NO:13 and a light chain comprising the amino acid sequence of SEQ ID NO:10.

[0026] A seventeenth aspect includes the antibody of the sixteenth aspect, wherein the antibody comprises a heavy chain comprising the amino acid sequence of SEQ ID NO:13 and a light chain comprising the amino acid sequence of SEQ ID NO:10.

[0027] An eighteenth aspect comprises the antibody of the sixteenth aspect, wherein the antibody comprises a heavy chain comprising the amino acid sequence of SEQ ID NO:9 and a light chain comprising the amino acid sequence of SEQ ID NO:10.

[0028] The nineteenth aspect includes a polynucleotide or a set of polynucleotides encoding the antibody or a portion thereof of any one of the twelfth to eighteenth aspects.

[0029] A twentieth aspect comprises a vector or set of vectors comprising the polynucleotide or set of polynucleotides of the nineteenth aspect.

[0030] A twenty-first aspect comprises a host cell comprising a polynucleotide or set of polynucleotides of the nineteenth aspect, or a vector or set of vectors of the twentieth aspect.

[0031] A twenty-second aspect includes a pharmaceutical composition comprising the antibody of any one of the twelfth to eighteenth aspects and a pharmaceutically acceptable carrier.

[0032] A twenty-third aspect comprises a method for producing an anti-CD79b antibody-drug conjugate, the method comprising conjugating an anti-CD79b antibody of any one of the twelfth to eighteenth aspects to a Topli payload shown as Formula 2 via a linker shown as Formula 3.

[0033] A twenty-fourth embodiment comprises a composition comprising an anti-CD79b antibody-drug conjugate, wherein the composition has a DAR of about 4. [Brief explanation of the drawings]

[0034] [Figure 1] 1 shows the results of an in vivo assay performed on ADC-1. [Figure 2] 1 shows the results of an in vivo assay performed on ADC-1 compared to polatuzumab vedotin-piiq. DETAILED DESCRIPTION OF THE INVENTION

[0035] Disclosed herein are embodiments that include anti-CD79b antibodies and anti-CD79b Top1i ADCs that include an anti-CD79b antibody and a Top1i drug. Embodiments also include Top1i linker-drugs useful for synthesizing anti-CD79b Top1i ADCs, methods of making anti-CD79b Top1i ADCs, and methods of using anti-CD79b Top1i ADCs.

[0036] 1.1 Anti-CD79b antibody Embodiments of the present disclosure are directed to an anti-CD79b antibody, Ab1, that specifically binds to CD79b. In certain embodiments, the anti-CD79b antibody specifically binds to human CD79b. In embodiments, the anti-CD79b antibody does not specifically bind to human CD79a. In embodiments, the anti-CD79b antibody has no cross-reactivity with mouse, rat, rabbit, dog, or cynomolgus monkey CD79b.

[0037] In embodiments, the anti-CD79b antibody comprises a heavy chain variable region (VH) comprising the amino acid sequence of SEQ ID NO:7, with a heavy chain variable region complementarity determining region 1 (VH-CDR1), a heavy chain variable region complementarity determining region 2 (VH-CDR2), and a heavy chain variable region complementarity determining region 3 (VH-CDR3) set forth therein; and a light chain variable region (VL) comprising the amino acid sequence of SEQ ID NO:8, with a light chain variable region complementarity determining region 1 (VL-CDR1), a light chain variable region complementarity determining region 2 (VL-CDR2), and a light chain variable region complementarity determining region 3 (VL-CDR3).

[0038] In certain embodiments, an anti-CD79b antibody comprises a VH-CDR1 comprising the amino acid sequence of SEQ ID NO: 1, a VH-CDR2 comprising the amino acid sequence of SEQ ID NO: 2, a VH-CDR3 comprising the amino acid sequence of SEQ ID NO: 3, a VL-CDR1 comprising the amino acid sequence of SEQ ID NO: 4, a VL-CDR2 comprising the amino acid sequence of SEQ ID NO: 5, and a VL-CDR3 comprising the amino acid sequence of SEQ ID NO: 6. In certain embodiments, an anti-CD79b antibody comprises a VH-CDR1 comprising the amino acid sequence of SEQ ID NO: 14, a VH-CDR2 comprising the amino acid sequence of SEQ ID NO: 15, a VH-CDR3 comprising the amino acid sequence of SEQ ID NO: 16, a VL-CDR1 comprising the amino acid sequence of SEQ ID NO: 17, a VL-CDR2 comprising the amino acid sequence of SEQ ID NO: 18, and a VL-CDR3 comprising the amino acid sequence of SEQ ID NO: 19.

[0039] In certain embodiments, an anti-CD79b antibody comprises a VH comprising the amino acid sequence of SEQ ID NO: 7 and / or a VL comprising the amino acid sequence of SEQ ID NO: 8. In certain embodiments, an anti-CD79b antibody comprises a VH comprising the amino acid sequence of SEQ ID NO: 7 and a VL comprising the amino acid sequence of SEQ ID NO: 8.

[0040] In certain embodiments, the anti-CD79b antibody comprises a heavy chain comprising the amino acid sequence of SEQ ID NO: 9 or SEQ ID NO: 13 and a light chain comprising the amino acid sequence of SEQ ID NO: 10. In embodiments, the predominant species of heavy chain of Ab1 comprises a heavy chain sequence lacking the C-terminal lysine, comprising a heavy chain sequence comprising the amino acid sequence of SEQ ID NO: 13.

[0041] In certain embodiments, the anti-CD79b antibody disclosed herein is a monoclonal antibody. In certain embodiments, the anti-CD79b antibody is an IgG1 antibody. In certain embodiments, the anti-CD79b antibody comprises a kappa light chain constant region (e.g., a human kappa light chain constant region). In certain embodiments, the anti-CD79b antibody was derived from Alivamab® (Ablexis), a fully recombinant humanized monoclonal IgG1 antibody produced in mice and comprising a human kappa light chain constant region.

[0042] In certain embodiments, the anti-CD79b antibody is designated herein as "Ab1" and comprises the amino acid sequence and Kabat- and IMGT-designated CDRs shown in Table 1.

[0043] [Table 1] TIFF2026004267000003.tif244163TIFF2026004267000004.tif245165TIFF2026004267000005.tif141168

[0044] In embodiments, the anti-CD79b antibody may be in a format such as an IgG1 or IgG4 format and has been modified to confer desired properties, such as having an Fc mutated to reduce or "silence" effector function or to extend half-life. In embodiments in which half-life extending and / or Fc silencing mutations have been introduced, the anti-CD79b antibody may comprise the following heavy chain sequences in the antibody combinations shown in Table 2:

[0045] [Table 2] TIFF2026004267000007.tif243169TIFF2026004267000008.tif243169TIFF2026004267000009.tif235169TIFF2026004267000010.tif248169TIFF2026004267000011.tif241169TIFF2026004267000012.tif243168TIFF2026004267000013.tif243168TIFF2026004267000014.tif243169TIFF2026004267000015.tif243168TIFF2026004267000016.tif248169TIFF2026004267000017.tif240169TIFF2026004267000018.tif242168TIFF2026004267000019.tif243169TIFF2026004267000020.tif247168TIFF2026004267000021.tif243169TIFF2026004267000022.tif248169TIFF2026004267000023.tif241169TIFF2026004267000024.tif242169TIFF2026004267000025.tif243169TIFF2026004267000026.tif245170TIFF2026004267000027.tif243169TIFF2026004267000028.tif248169TIFF2026004267000029.tif240169TIFF2026004267000030.tif242168TIFF2026004267000031.tif242169TIFF2026004267000032.tif243168TIFF2026004267000033.tif243169TIFF2026004267000034.tif248169TIFF2026004267000035.tif241169TIFF2026004267000036.tif242169TIFF2026004267000037.tif243168TIFF2026004267000038.tif243169TIFF2026004267000039.tif242169TIFF2026004267000040.tif248169TIFF2026004267000041.tif241169TIFF2026004267000042.tif243169TIFF2026004267000043.tif245169TIFF2026004267000044.tif58168.

[0046] Embodiments of anti-CD79b antibodies may include an IgG1 heavy chain comprising an amino acid sequence according to SEQ ID NOs: 9, 13, and 20-53. In embodiments, an anti-CD79b antibody may include a wild-type IgG1 heavy chain comprising an amino acid sequence according to SEQ ID NO: 9 (with a terminal lysine) and SEQ ID NO: 13 (without a terminal lysine). In embodiments, the IgG1 heavy chain comprises an Fc-silencing mutation selected from L234A, L235A (LALA) or L234S, L235T, G236R (STR). In embodiments, an anti-CD79b antibody includes an IgG1 heavy chain comprising the mutations L234A, L235A (LALA), with or without a terminal lysine. In embodiments, an anti-CD79b antibody includes an IgG1 heavy chain comprising the mutations L234S, L235T, G236R (STR), with or without a terminal lysine. In embodiments, an anti-CD79b antibody may comprise an IgG1 heavy chain comprising a half-life extending mutation selected from M252Y, S254T, T256E (YTE); Q311R, M428E, N434W (REW); M428L, N434S (LS); L309D, Q311H, N434S (DHS); or T250Q, M428L (QL). In embodiments, an anti-CD79b antibody comprises an IgG1 heavy chain comprising M252Y, S254T, T256E (YTE), with or without a terminal lysine. In embodiments, an anti-CD79b antibody comprises an IgG1 heavy chain comprising Q311R, M428E, N434W (REW), with or without a terminal lysine. In embodiments, the anti-CD79b antibody comprises an IgG1 heavy chain comprising M428L, N434S (LS), with or without a terminal lysine. In embodiments, the anti-CD79b antibody comprises an IgG1 heavy chain comprising L309D, Q311H, N434S (DHS), with or without a terminal lysine. In embodiments, the anti-CD79b antibody comprises an IgG1 heavy chain comprising T250Q, M428L (QL), with or without a terminal lysine. In embodiments, the anti-CD79b antibody may comprise both Fc-silencing mutations and half-life extending mutations. In embodiments, the anti-CD79b antibody comprises an IgG1 heavy chain comprising the mutations L234A, L235A (LALA) and M252Y, S254T, T256E (YTE), with or without a terminal lysine.In embodiments, the anti-CD79b antibody comprises an IgG1 heavy chain comprising the mutations L234S, L235T, G236R (STR) and M252Y, S254T, T256E (YTE), with or without a terminal lysine. In embodiments, the anti-CD79b antibody comprises an IgG1 heavy chain comprising the mutations L234A, L235A (LALA) and Q311R, M428E, N434W (REW), with or without a terminal lysine. In embodiments, the anti-CD79b antibody comprises an IgG1 heavy chain comprising the mutations L234S, L235T, G236R (STR) and Q311R, M428E, N434W (REW), with or without a terminal lysine. In embodiments, the anti-CD79b antibody comprises an IgG1 heavy chain comprising the mutations L234A, L235A (LALA) and M428L, N434S (LS), with or without a terminal lysine. In embodiments, the anti-CD79b antibody comprises an IgG1 heavy chain comprising the mutations L234S, L235T, G236R (STR) and M428L, N434S (LS), with or without a terminal lysine. In embodiments, the anti-CD79b antibody comprises an IgG1 heavy chain comprising the mutations L234A, L235A (LALA) and L309D, Q311H, N434S (DHS), with or without a terminal lysine. In embodiments, the anti-CD79b antibody comprises an IgG1 heavy chain comprising the mutations L234S, L235T, G236R (STR) and L309D, Q311H, N434S (DHS), with or without a terminal lysine. In embodiments, the anti-CD79b antibody comprises an IgG1 heavy chain comprising the mutations L234A, L235A (LALA) and T250Q, M428L (QL), with or without a terminal lysine. In embodiments, the anti-CD79b antibody comprises an IgG1 heavy chain comprising the mutations L234S, L235T, G236R (STR) and T250Q, M428L (QL), with or without a terminal lysine.

[0047] Embodiments of anti-CD79b antibodies may comprise an IgG4 heavy chain comprising an amino acid sequence according to SEQ ID NOs: 54-125. In embodiments, anti-CD79b antibodies may comprise wild-type IgG4 heavy chains comprising an amino acid sequence according to SEQ ID NO: 122 (with a terminal lysine) and SEQ ID NO: 123 (without a terminal lysine). In embodiments, anti-CD79b antibodies may comprise an IgG4 heavy chain further comprising an S228P mutation according to SEQ ID NO: 124 (with a terminal lysine) and SEQ ID NO: 125 (without a terminal lysine). In embodiments, the IgG4 heavy chain comprises an Fc silencing mutation selected from F234A, L235A (FALA) or L234S, L235T, G236R (STR). In embodiments, anti-CD79b antibodies comprise an IgG4 heavy chain comprising the mutations F234A, L235A (FALA), with or without a terminal lysine, and with or without an S228P mutation. In embodiments, an anti-CD79b antibody comprises an IgG4 heavy chain comprising the mutations L234S, L235T, G236R (STR), with or without a terminal lysine, and with or without an S228P mutation. In embodiments, an anti-CD79b antibody may comprise an IgG4 heavy chain comprising a half-life extending mutation selected from M252Y, S254T, T256E (YTE); Q311R, M428E, N434W (REW); M428L, N434S (LS); L309D, Q311H, N434S (DHS); or T250Q, M428L (QL). In embodiments, an anti-CD79b antibody comprises an IgG4 heavy chain comprising M252Y, S254T, T256E (YTE), with or without a terminal lysine, and with or without an S228P mutation. In embodiments, the anti-CD79b antibody comprises an IgG4 heavy chain comprising Q311R, M428E, N434W (REW), with or without a terminal lysine, and with or without an S228P mutation. In embodiments, the anti-CD79b antibody comprises an IgG4 heavy chain comprising M428L, N434S (LS), with or without a terminal lysine, and with or without an S228P mutation. In embodiments, the anti-CD79b antibody comprises an IgG4 heavy chain comprising L309D, Q311H, N434S (DHS), with or without a terminal lysine, and with or without an S228P mutation.In embodiments, an anti-CD79b antibody comprises an IgG4 heavy chain comprising T250Q, M428L (QL), with or without a terminal lysine, and with or without an S228P mutation. In embodiments, an anti-CD79b antibody may comprise both an Fc-silencing mutation and a half-life extending mutation. In embodiments, an anti-CD79b antibody comprises an IgG4 heavy chain comprising mutations F234A, L235A (FALA) and M252Y, S254T, T256E (YTE), with or without a terminal lysine, and with or without an S228P mutation. In embodiments, an anti-CD79b antibody comprises an IgG4 heavy chain comprising mutations L234S, L235T, G236R (STR) and M252Y, S254T, T256E (YTE), with or without a terminal lysine, and with or without an S228P mutation. In embodiments, the anti-CD79b antibody comprises an IgG4 heavy chain comprising the mutations F234A, L235A (FALA) and Q311R, M428E, N434W (REW), with or without a terminal lysine, and with or without a S228P mutation. In embodiments, the anti-CD79b antibody comprises an IgG4 heavy chain comprising the mutations L234S, L235T, G236R (STR) and Q311R, M428E, N434W (REW), with or without a terminal lysine, and with or without a S228P mutation. In embodiments, the anti-CD79b antibody comprises an IgG4 heavy chain comprising the mutations F234A, L235A (FALA) and M428L, N434S (LS), with or without a terminal lysine, and with or without a S228P mutation. In embodiments, the anti-CD79b antibody comprises an IgG4 heavy chain comprising the mutations L234S, L235T, G236R (STR) and M428L, N434S (LS), with or without a terminal lysine, and with or without a S228P mutation. In embodiments, the anti-CD79b antibody comprises an IgG4 heavy chain comprising the mutations F234A, L235A (FALA) and L309D, Q311H, N434S (DHS), with or without a terminal lysine, and with or without a S228P mutation.In embodiments, the anti-CD79b antibody comprises an IgG4 heavy chain comprising the mutations L234S, L235T, G236R (STR) and L309D, Q311H, N434S (DHS), with or without a terminal lysine, and with or without an S228P mutation. In embodiments, the anti-CD79b antibody comprises an IgG4 heavy chain comprising the mutations F234A, L235A (FALA) and T250Q, M428L (QL), with or without a terminal lysine, and with or without an S228P mutation. In embodiments, the anti-CD79b antibody comprises an IgG4 heavy chain comprising the mutations L234S, L235T, G236R (STR) and T250Q, M428L (QL), with or without a terminal lysine, and with or without an S228P mutation.

[0048] In certain embodiments, the anti-CD79b antibody comprises a heavy chain comprising the amino acid sequence encoded by the nucleotide sequence of SEQ ID NO:11; and / or a light chain comprising the amino acid sequence encoded by the nucleotide sequence of SEQ ID NO:12.

[0049] The present disclosure further provides polynucleotides encoding the anti-CD79b antibodies disclosed herein or one or more chains thereof. In certain embodiments, the present disclosure provides a set of polynucleotides encoding the anti-CD79b antibodies disclosed herein. In certain embodiments, the polynucleotides encode the heavy chain or light chain of the anti-CD79b antibodies disclosed herein. In certain embodiments, the polynucleotides encode the heavy chain and light chain of the anti-CD79b antibodies disclosed herein. In certain embodiments, the set of polynucleotides comprises a polynucleotide encoding the heavy chain of the anti-CD79b antibodies disclosed herein and a polynucleotide encoding the light chain of the anti-CD79b antibodies disclosed herein.

[0050] The polynucleotides disclosed herein include polynucleotides that include only the coding sequence of an anti-CD79b antibody or a portion thereof, as well as polynucleotides that include additional coding and / or non-coding sequences. The polynucleotides disclosed herein may be in the form of RNA or DNA (e.g., cDNA, genomic DNA, and synthetic DNA), whether double-stranded or single-stranded.

[0051] In certain embodiments, the polynucleotides encode the VH or VL of an anti-CD79b antibody disclosed herein. In certain embodiments, the polynucleotides encode the VH and VL of an anti-CD79b antibody disclosed herein. In certain embodiments, the set of polynucleotides comprises a polynucleotide encoding the VH of an anti-CD79b antibody disclosed herein and a polynucleotide encoding the VL of an anti-CD79b antibody disclosed herein.

[0052] In certain embodiments, provided herein is a vector or set of vectors comprising a polynucleotide or set of polynucleotides disclosed herein, wherein the polynucleotide or set of polynucleotides encodes an anti-CD79b antibody, or a portion thereof, disclosed herein.

[0053] Polynucleotides may be present in whole cells, in a cell lysate, or in a partially purified or substantially pure form. A polynucleotide is isolated or substantially pure when it is separated from other cellular components or other contaminants, such as other cellular nucleic acids or proteins, by standard techniques known in the art, including, but not limited to, alkali / SDS treatment, CsCl banding, column chromatography, and agarose gel electrophoresis.

[0054] The polynucleotides of the embodiments described herein can be obtained using standard molecular biology techniques. For antibodies expressed by hybridomas, cDNAs encoding the antibody light and heavy chains can be obtained by standard PCR amplification or cDNA cloning techniques. For antibodies obtained from an immunoglobulin gene library (e.g., using phage display technology), polynucleotides encoding the antibody can be recovered from the library.

[0055] Disclosed herein, in certain embodiments, is a pharmaceutical composition comprising an anti-CD79b antibody disclosed herein and a pharmaceutically acceptable carrier.

[0056] The variable regions (e.g., VH and VL) are the portions of the light or heavy chain of an antibody that are primarily responsible for the specific binding of each antibody to its particular antigen. Each variable region contains framework regions (FR) and complementarity-determining regions (CDR). The FRs are low-variability stretches of the variable region, separated by shorter regions of high variability, the CDRs.

[0057] 1.2 Topoisomerase 1 inhibitors (Top1i) Topoisomerase 1 (Top1) is an enzyme that removes supercoils formed during DNA replication. Top1 inhibitors (Top1i) can bind to and stabilize Top1-DNA complexes, thereby inducing DNA strand breaks and apoptosis.

[0058] Disclosed herein are Top1i drugs according to structural formula (I) that can be conjugated with anti-CD79b antibodies for targeted delivery to cells.

[0059] [ka]

[0060] In an embodiment, the Top1i drug is (7S)-14-(3-aminobicyclo[1.1.1]pentan-1-yl)-7-ethyl-7-hydroxy-2H,10H-[1,3]dioxolo[4,5-g]pyrano[3',4':6,7]indolizino[1,2-b]quinoline-8,11(7H,13H)-dione.

[0061] In certain embodiments, a Top1i drug contemplated herein has structural formula (II):

[0062] [ka] (In the formula,

[0063] [ka] represents the point of attachment of the linker to the Top1i drug).

[0064] 1.2.1 Linker Drug LD1 (Structural Formula (III))

[0065] [ka]

[0066] In certain embodiments, the Top1i linker drug (LD1) is a compound according to formula (III). In certain embodiments, LD1 is (2S)-2-(2-bromoacetamido)-N-[(2S)-1-({3-[(7S)-7-ethyl-7-hydroxy-8,11-dioxo-7,8,11,13-tetrahydro-2H,10H-[1,3]dioxolo[4,5-g]pyrano[3',4':6,7]indolizino[1,2-b]quinolin-14-yl]bicyclo[1.1.1]pentan-1-yl}amino)-1-oxopropan-2-yl]-3-methylbutanamide.

[0067] 1.3 Anti-CD79b Top1i ADC In certain embodiments, a Top1i drug disclosed herein (i.e., Formula (I)) can be conjugated to an anti-CD79b antibody disclosed herein to form an anti-CD79b Top1i ADC. The ADC can selectively deliver one or more drug moieties to a target tissue, such as a CD79b-expressing tumor. Thus, in certain embodiments, the present disclosure provides an anti-CD79b TOP1i ADC for therapeutic use in the treatment of B-cell malignancies.

[0068] In certain embodiments, a Top1i drug is conjugated to an anti-CD79b antibody by a linker moiety. In certain embodiments, the linker connects the Top1i drug to the anti-CD79b antibody by forming a covalent bond to the Top1i drug at one position and to the antibody at another position. In certain embodiments, the covalent bond is formed by reaction between functional groups on the linker and functional groups on the Top1i drug and anti-CD79b antibody. In certain embodiments, an anti-CD79b Top1i ADC of the present disclosure comprises an anti-CD79b antibody conjugated to a Top1i linker drug of formula (III).

[0069] 1.3.1 Number of linked drugs In certain embodiments, the anti-CD79b Top1i ADCs disclosed herein comprise drug molecules linked to antibody moieties in various stoichiometric molar ratios, depending, at least in part, on the composition of the antibody and the method used to effect conjugation.

[0070] The term "drug loading" or "drug loading" refers to the number of drug molecules per antibody in an individual ADC molecule.

[0071] The number of cytotoxic and / or cytostatic agents linked to the antigen-binding portion of an anti-CD79b Top1i ADC can vary (referred to as the "drug-to-antibody ratio" or "DAR"). The DAR is the average number of drugs linked to each antibody in a composition. The number of Top1i drugs linked to an anti-CD79b antibody to provide embodiments of the CD79b Top1i ADCs described herein can vary and is limited by the number of available attachment sites on the anti-CD79b antibody. As contemplated for the anti-CD79b Top1i ADCs described herein, a linker links a single Top1i drug to the anti-CD79b antibody in an anti-CD79b Top1i ADC. In certain embodiments, an anti-CD79b Top1i ADC has an n ranging from 1 to 8. In certain embodiments, an anti-CD79b Top1i ADC has an n of 1, 2, 3, 4, 5, 6, 7, or 8. In certain embodiments, the drug loading comprises 1 drug molecule, 2 drug molecules, 3 drug molecules, 4 drug molecules, 5 drug molecules, 6 drug molecules, 7 drug molecules, or 8 drug molecules. In embodiments, the anti-CD79b Top1i ADCs described herein may have a DAR ranging from about n=1 to 8 or 1 to 6. In certain embodiments, the anti-CD79b Top1i ADCs described herein have a DAR of 1 to 6 or about 6.

[0072] 1.3.2 Example ADC In certain embodiments, a compound of formula (IV):

[0073] [ka] and a VL-CDR1, VL-CDR2, and VL-CDR3 set forth in a VH comprising the amino acid sequence of SEQ ID NO: 7; and a VL-CDR1, VL-CDR2, and VL-CDR3 set forth in a VL comprising the amino acid sequence of SEQ ID NO: 8. In certain embodiments, the anti-CD79b antibody comprises a VH comprising the amino acid sequence of SEQ ID NO: 7 and a VL comprising the amino acid sequence of SEQ ID NO: 8. In certain embodiments, the anti-CD79b antibody comprises a VH comprising the amino acid sequence of SEQ ID NO: 7 and a VL comprising the amino acid sequence of SEQ ID NO: 8. In certain embodiments, the anti-CD79b antibody comprises a heavy chain comprising the amino acid sequence of SEQ ID NO:9 or SEQ ID NO:13 and a light chain comprising the amino acid sequence of SEQ ID NO:10. In certain embodiments, the conjugation of the linker-drug to the anti-CD79b antibody is via a linkage formed with a sulfhydryl group of a cysteine ​​residue of the anti-CD79b antibody. In embodiments, n has a value of 1, 2, 3, 4, 5, 6, 7, or 8.

[0074] As used herein, "ADC-1" refers to an anti-CD79b Top1i ADC composition comprising an anti-CD79b ADC according to structural formula (IV), where Ab1 comprises two heavy chains each comprising the amino acid sequence of SEQ ID NO:9 or SEQ ID NO:13 and two light chains each comprising the amino acid sequence of SEQ ID NO:10. Methods for producing ADC-1 are described in the Examples below. In certain embodiments, ADC-1 is an anti-CD79b ADC composition comprising multiple ADC-1 species having two or more different values ​​of n.

[0075] The anti-CD79b ADCs of the present disclosure may be provided as compositions suitable for administration to patients. In certain embodiments, the anti-CD79b ADC composition is a pharmaceutical composition comprising an anti-CD79b ADC of the present disclosure and a pharmaceutically acceptable carrier. A given formulation of an anti-CD79b ADC disclosed herein may contain a distribution of antibodies with different values ​​of n.

[0076] 1.4 How to use The present disclosure further provides a method for treating a B-cell malignancy, comprising administering to a subject in need thereof a therapeutically effective amount of an ADC of Formula (IV). In certain embodiments, the B-cell malignancy is B-NHL, including but not limited to DLBCL, BL, MCL, and FL.

[0077] The terms "patient," "subject," "individual," and the like refer to a human.

[0078] As used herein, the terms "treat," "treating," and "treatment" refer to a method of alleviating or eliminating a disease and / or its associated symptoms.

[0079] The phrase "therapeutically effective amount" refers to that amount of an ADC that, when administered for treatment in a particular subject or subject population, is sufficient to prevent the onset of, or alleviate to some extent, one or more of the symptoms of, the condition or disorder being treated. [Example]

[0080] 2. Working Example The following examples, which highlight certain features and characteristics of exemplary embodiments of the ADCs, antibodies and Top1i's described herein, are provided for illustrative purposes.

[0081] [Example 1] 2.1 Example 1: Screening and Preparation of Ab1 The anti-CD79b antibody was derived from recombinant fully human immunoglobulin G1 and generated using AlivaMab® (Ablexis) mice. CD79b monoclonal antibody candidates were identified based on expression, in vitro binding to human CD79b, lack of binding to human CD79a, and potency against B-NHL cancer cells when conjugated with the Top1i payload.

[0082] Sequence information for anti-CD79b Ab1 is provided in Table 1. Ab1 was expressed in Chinese hamster ovary (CHO) cells with heavy and light chain sequences of SEQ ID NOs: 9 or 13 and 10, respectively. Ab1 was isolated and purified prior to conjugation.

[0083] [Example 2] 2.2 Example 2: Conjugation Procedure for Producing ADC-1 Conjugation Step 1 A solution of antibody (17.9 mg / mL) in DPBS (Dulbecco's phosphate-buffered saline, pH 7.2, containing 5 mM ethylenediaminetetraacetic acid (EDTA)) at 4° C. was treated with tris(2-carboxyethyl)phosphine hydrochloride (TCEP, 10 mM, 5 molar equivalents, Bond-Breaker®, Thermo Scientific®) for 20 hours at 4° C. After incubation, the pH was adjusted by adding 1 M borate buffer (10% v / v, pH 8), followed by the addition of an excess (10 equivalents) of a linker drug according to structural formula (III) (in 10 mM dimethylacetamide (DMA) solution).

[0084] The reaction mixture was kept in the dark at room temperature for 1 hour. The resulting ADC was purified. The resulting ADC solution was filtered and stored in an amber tube at 4°C, DAR=6.05.

[0085] Determination of DAR. DAR was determined by LC-MS or HIC (hydrophobic interaction chromatography). LC-MS analysis was performed using an Agilent 1100 HPLC system connected to an Agilent LC / MSD TOF (Time-of-Flight) 6220 ESI mass spectrometer. The ADC was reduced with 5 mM (final concentration) Bond-Breaker® TCEP solution (Thermo Scientific®, Rockford, IL), loaded onto a protein microtrap (Michrom BioResources) desalting cartridge, and eluted with a gradient from 10% B to 75% B in 0.2 min at ambient temperature. Mobile phase A was HO containing 0.1% formic acid (FA), and mobile phase B was acetonitrile containing 0.1% FA at a flow rate of 0.2 mL / min. Electrospray ionization time-of-flight mass spectra of the coeluting light and heavy chains were collected using Agilent MassHunter acquisition software. The extracted intensity vs. m / z spectra were deconvoluted using the Maximum Entropy function of MassHunter software to determine the mass of each reduced antibody fragment. The DAR was calculated from the deconvoluted spectra by summing the intensities of the bare and modified peaks of the light and heavy chains and normalizing the intensity by multiplying it by the number of drugs bound to them. The summed normalized intensity was divided by the sum of the intensities, and the summed results for the two light chains and two heavy chains gave the final average DAR value for the entire ADC.

[0086] Peptide mapping was performed to determine modifications or deletions to the amino acids present in the heavy and light chains of Ab1. After denaturation, reduction, and alkylation, Ab1 was subjected to digestion using the protease Lys-C, which cleaves peptide bonds at the C-terminus of lysine. The digested samples were analyzed using reverse-phase high-performance liquid chromatography (HPLC).

[0087] Analysis of two batches of Ab1 peptide fragments after proteolytic digestion showed the presence of two species of heavy chain. Total ion current (TIC) chromatograms were generated. A small percentage (2.9 percent) of the heavy chains of Ab1 consisted of heavy chains with a C-terminal lysine, as set forth in SEQ ID NO:9. The predominant species of heavy chain in Ab1 lacked a C-terminal lysine, as set forth in SEQ ID NO:13.

[0088] [Example 3] 2.3 Example 3: Binding Affinity of ADC-1 Polatuzumab vedotin-piiq is a CD79b-directed ADC used to treat B-NHL.

[0089] ADC-1 produced by the procedure of Example 3 has the following structure:

[0090] [ka] where n is 6 and Ab is anti-CD79b antibody Ab1.

[0091] The binding affinity of ADC-1 and polatuzumab vedotin-piiq to human CD79b was measured. The binding ligand used in the assay was recombinant human CD79b, which has the amino acid sequence Ala29-Asp159 of human CD79b, fused to a 6-His tag at the C-terminus. Table 3 shows the measured association rates (k a ), dissociation rate (k d ) and the equilibrium dissociation constant (K D ) is provided.

[0092] [Table 3]

[0093] [Example 4] 2.4 Example 4: In vitro cytotoxicity The in vitro cytotoxicity of ADC-1 and polatuzumab vedotin-piiq was measured in a number of B-NHL cell lines, including DoHH2, HBL-1, JEKO, REC-1, Ramos, and SuDHL-4. SuDHL-4 and DoHH2 are DLBCL-germinal center B cell-like (GCB) cell lines; HBL-1 is a DLBCL-activated B cell-like (ABC) cell line; Ramos is a BL cell line; and JEKO and REC-1 are MCL cell lines. Table 4 shows the in vitro cytotoxicity results.

[0094] [Table 4]

[0095] [Example 5] 2.5 Example 5: In vivo cytotoxicity In vivo growth inhibition of ADC-1-treated DLBCL ABC CDX tumors (U-2932) was measured at multiple doses of ADC-1, including the initial dose level (1x), twice the initial dose level (2x), and four times the initial dose level (4x). Each dose of ADC-1 was administered as a single intraperitoneal bolus on day 0. ADC-1 induced statistically significant tumor growth inhibition and tumor growth delay compared with vehicle control. As shown in Figure 1, administration of ADC-1 to xenografted DLBCL ABC CDX tumors significantly reduced tumor volume over 110 days at all dose levels tested. 100% CR was observed at all dose levels.

[0096] In addition, Table 5 shows the in vivo antitumor effects. Administration of ADC-1 resulted in statistically significant (p < 0.05) reductions compared to vehicle control at all dose levels tested. **p<0.01) TGI (100% at day 35 post-dose) and TGD (>200% at study termination) were induced. In all cases, the reported TGI is the "last" TGI for the "depth" of response indicator. TGI (tumor growth inhibition) % = 1 - (mean tumor volume of treatment group / mean tumor volume of treatment control group) x 100. For TGI %, P values ​​(indicated by an asterisk) are derived from test comparisons of treatment groups vs. treatment control groups after log10 transformation of tumor volume data. Tests for TGI % were performed on data from the last day all animals in the control group were present / alive. TGD is an indicator of response durability. TGD (tumor growth delay) % = (TC) / C x 100, where T is the median time to endpoint for the treatment group and C is the median time to endpoint for the treatment control group. For TGD%, P values ​​(indicated by an asterisk) are derived from Kaplan-Meier log-rank comparisons of treatment groups versus treatment control groups. Based on an endpoint of 1000 mm3. Fisher's exact test for response frequencies was used to compare treatment and treatment control groups. CR: complete response, % of the population with tumors less than 25 mm3 for at least three consecutive measurements; PR: partial response, % of the population with tumors greater than 25 mm3 for at least three consecutive measurements and less than 50% of the original tumor volume at the start of treatment; OR: overall response = TFE + CR + PR; TFE: tumor-free event, % of the population with complete tumor regression at the end of the study as determined by palpation.

[0097] [Table 5]

[0098] [Example 6] 2.6 Example 6: In vivo cytotoxicity In vivo growth inhibition of DLBCL GCB CDX tumors (OCI Ly19) treated with ADC-1 or polatuzumab vedotin-piiq was measured at multiple dose levels of ADC-1, including the initial dose level (1x) and three times the initial dose level (3x), or polatuzumab vedotin-piiq at three times the initial dose level of ADC-1. Each dose of ADC-1 or polatuzumab vedotin-piiq was administered as a single intraperitoneal bolus on day 0. As shown in Figure 2, administration of ADC-1 to xenografted DLBCL GCB CDX tumors induced statistically significant tumor growth inhibition and tumor growth delay at all dose levels tested compared to vehicle control. 100% CR was observed at all dose levels. Administration of polatuzumab vedotin-piiq to xenografted DLBCL GCB CDX tumors induced statistically significant tumor growth inhibition and tumor growth delay at the dose levels tested compared to vehicle control. No CRs were observed at the dose levels tested. Administration of ADC-1 to xenografted DLBCL GCB CDX tumors induced statistically significant tumor growth inhibition and tumor growth delay at all dose levels tested compared to tumors treated with polatuzumab vedotin-piiq.

[0099] In addition, Table 6 shows the in vivo antitumor effects. Administration of ADC-1 resulted in statistically significant (p < 0.05) increases in tumor size at the 1-fold and 3-fold dose levels, respectively, compared to the vehicle control. ** Administration of polatuzumab vedotin-piiq induced a statistically significant (p<0.01) TGI (100% at 10 days post-treatment) and TGD (>320% and >460% at the end of the study). ** p<0.01). Administration of ADC-1 induced statistically significant (p<0.01) TGI (84% at 10 days post-administration) and TGD (90% at the end of the study) reductions compared with polatuzumab vedotin-piiq at the 1x and 3x dose levels, respectively. ** p<0.01) induced TGI (99% at 14 days post-administration) and TGD (>121% and >195% at the end of the study).

[0100] [Table 6]

[0101] All patents and publications mentioned herein are incorporated by reference in their entirety. From the foregoing description, it will be apparent that variations and modifications can be made to the embodiments described herein to adapt them to various uses and conditions. Such embodiments also fall within the scope of the following claims.

[0102] [Table 7] TIFF2026004267000056.tif246169TIFF2026004267000057.tif248169TIFF2026004267000058.tif245170TIFF2026004267000059.tif240169TIFF2026004267000060.tif250169TIFF2026004267000061.tif245169TIFF2026004267000062.tif249170TIFF2026004267000063.tif246169TIFF2026004267000064.tif246169TIFF2026004267000065.tif240169TIFF2026004267000066.tif250169TIFF2026004267000067.tif235169TIFF2026004267000068.tif245169TIFF2026004267000069.tif245169TIFF2026004267000070.tif245169TIFF2026004267000071.tif245169TIFF2026004267000072.tif240168TIFF2026004267000073.tif249169TIFF2026004267000074.tif245169TIFF2026004267000075.tif235166TIFF2026004267000076.tif249169TIFF2026004267000077.tif245169TIFF2026004267000078.tif240169TIFF2026004267000079.tif250169TIFF2026004267000080.tif245169TIFF2026004267000081.tif245169TIFF2026004267000082.tif217170

Claims

1. The following structure: 【Chemistry 1】 (wherein n is an integer from 1 to 8; Ab1 is an anti-CD79b antibody comprising a heavy chain variable region comprising VH-CDR1, VH-CDR2, and VH-CDR3; and a light chain variable region comprising VL-CDR1, VL-CDR2, and VL-CDR3; VH-CDR1 has the amino acid sequence of SEQ ID NO: 1; VH-CDR2 has the amino acid sequence of SEQ ID NO:2; VH-CDR3 has the amino acid sequence of SEQ ID NO: 3; VL-CDR1 has the amino acid sequence of SEQ ID NO:4; VL-CDR2 has the amino acid sequence of SEQ ID NO:5; and VL-CDR3 has the amino acid sequence of SEQ ID NO: 6 Anti-CD79b antibody-drug conjugates (ADCs).

2. Ab1 is IgG １ 2. The anti-CD79b ADC of claim 1, wherein the ADC is of the isotype and comprises a heavy chain variable region having the amino acid sequence of SEQ ID NO: 7; and a light chain variable region having the amino acid sequence of SEQ ID NO:

8.

3. Ab1 is IgG １ 2. The anti-CD79b ADC of claim 1, wherein the ADC is of the isotype and comprises a heavy chain having the amino acid sequence of SEQ ID NO: 9 or SEQ ID NO: 13; and a light chain having the amino acid sequence of SEQ ID NO:

10.

4. 4. The anti-CD79b ADC of claim 3, wherein Ab1 comprises a heavy chain having the amino acid sequence of SEQ ID NO: 13; and a light chain having the amino acid sequence of SEQ ID NO:

10.

5. 5. The anti-CD79b ADC of claim 4, wherein n is 6.

6. 4. The anti-CD79b ADC of claim 3, wherein Ab1 comprises a heavy chain having the amino acid sequence of SEQ ID NO: 9; and a light chain having the amino acid sequence of SEQ ID NO:

10.

7. 7. The anti-CD79b ADC of claim 6, wherein n is 6.

8. 3. The anti-CD79b ADC of claim 1 or 2, wherein the anti-CD79b antibody comprises two identical heavy chains and two identical light chains, each heavy chain comprising the amino acid sequence of SEQ ID NO:9 or SEQ ID NO:13, and each light chain comprising the amino acid sequence of SEQ ID NO:

10.

9. 3. The anti-CD79b ADC of claim 1 or 2, wherein the anti-CD79b antibody comprises a human kappa light chain constant region.

10. A pharmaceutical composition comprising the anti-CD79b ADC of any one of claims 1 to 9 and a pharmaceutically acceptable carrier.

11. A method for treating a disease, comprising administering to a patient in need thereof an anti-CD79b ADC of claims 1-9.

12. An antibody that specifically binds to human CD79b, comprising: a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 7; and a light chain variable region comprising the amino acid sequence of SEQ ID NO:

8.

13. IgG １ The antibody of claim 12, wherein the antibody is an isotype, and the VH-CDR1 comprises the amino acid sequence of SEQ ID NO: 1, the VH-CDR2 comprises the amino acid sequence of SEQ ID NO: 2, the VH-CDR3 comprises the amino acid sequence of SEQ ID NO: 3, the VL-CDR1 comprises the amino acid sequence of SEQ ID NO: 4, the VL-CDR2 comprises the amino acid sequence of SEQ ID NO: 5, and the VL-CDR3 comprises the amino acid sequence of SEQ ID NO:

6.

14. The antibody of claim 12 or 13, comprising a human kappa light chain constant region.

15. The antibody of any one of claims 12 to 14, comprising a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 7 and a light chain variable region comprising the amino acid sequence of SEQ ID NO:

8.

16. The antibody of any one of claims 12 to 15, comprising a heavy chain comprising the amino acid sequence of SEQ ID NO: 9 or SEQ ID NO: 13 and a light chain comprising the amino acid sequence of SEQ ID NO:

10.

17. The antibody of claim 16, comprising a heavy chain comprising the amino acid sequence of SEQ ID NO: 13 and a light chain comprising the amino acid sequence of SEQ ID NO:

10.

18. The antibody of claim 16, comprising a heavy chain comprising the amino acid sequence of SEQ ID NO: 9 and a light chain comprising the amino acid sequence of SEQ ID NO:

10.

19. A polynucleotide or set of polynucleotides encoding the antibody or a part thereof according to any one of claims 12 to 18.

20. 20. A vector or set of vectors comprising the polynucleotide or set of polynucleotides of claim 19.

21. 21. A host cell comprising a polynucleotide or set of polynucleotides according to claim 19, or a vector or set of vectors according to claim 20.

22. A pharmaceutical composition comprising the antibody of any one of claims 12 to 18 and a pharmaceutically acceptable carrier.

23. 19. A method for producing an anti-CD79b antibody-drug conjugate, the method comprising conjugating an anti-CD79b antibody of any one of claims 12 to 18 to a Topli payload shown as formula 2 via a linker shown as formula 3.

24. A composition comprising an anti-CD79b antibody-drug conjugate, wherein the composition has a DAR of about 4.

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