Methods of treatment and diagnosis of multiple myeloma

Abstract

The present invention provides methods of administration directed to the treatment of cancer, such as multiple myeloma, with an anti-crystallizable fragment receptor-like 5 (FcRH5) / anti-cluster of differentiation 3 (CD3) bispecific antibody.

Description

[0001] Sequence Listing

[0002] This application contains a sequence listing, which has been submitted electronically in XML format and is incorporated herein by reference in its entirety. The XML copy was created on October 4, 2023, named 50474-309WO2_Sequence_Listing_10_4_23, and is 41,573 bytes in size. Technical Field

[0003] The present invention relates to the treatment of cancers such as B-cell proliferative disorders, and methods of monitoring and assessing such treatments. More specifically, the present invention relates to the treatment of T-cell proliferation markers (e.g., the levels of the proliferation marker Ki-67 (MKI67)) and / or increased MKI67 + Treatment, monitoring and assessment of the number of T cells in multiple myeloma (MM) patients. Anti-crystallizable fragment receptor-like 5 (FcRH5) / anti-cluster of differentiation 3 (CD3) bispecific antibodies can be used for treatment. Background Art

[0004] Cancer remains one of the most deadly threats to human health, striking more than 1.7 million new patients each year and being the second leading cause of death after heart disease in the United States, accounting for approximately one in four deaths.

[0005] In particular, blood cancers are the second leading cause of cancer-related deaths. Blood cancers include multiple myeloma (MM), a tumor characterized by the proliferation and accumulation of malignant plasma cells. Approximately 110,000 people are diagnosed with MM each year worldwide. Despite advances in treatment, MM remains incurable, with an estimated median survival of 8 to 10 years for standard-risk myeloma and 2 to 3 years for high-risk disease, even with autologous stem cell transplantation. Although patient survival has improved significantly over the past 20 years, only 10% to 15% of patients meet or exceed expected survival compared to the matched general population. Prolonged survival has been achieved through the introduction of proteasome inhibitors, immunomodulatory drugs (IMiDs), and monoclonal antibodies. However, most patients, if not all, eventually relapse, and patients with MM have rather poor outcomes with survival of less than 1 year after becoming refractory or unsuitable for proteasome inhibitors or IMiDs. Therefore, relapsed or refractory (R / R) MM in particular remains a significant unmet medical need, and novel therapeutic agents are needed. For such patients, alternative or secondary treatment modalities, such as bispecific antibody-based immunotherapy, may be particularly effective. There is an unmet need in the art to develop effective methods for administering therapeutic bispecific antibodies (e.g., bispecific anti-FcRH5 / anti-CD3 antibodies) to treat cancer (e.g., MM, e.g., R / R MM) that achieve a more favorable benefit-risk profile. Summary of the invention

[0006] Provided herein are, inter alia, methods of treating a subject having cancer (eg, MM), methods of assessing treatment of cancer (eg, MM) in a subject, and methods of monitoring response to treatment of cancer (eg, MM) in a subject.

[0007] In one aspect, the invention features a method of treating a subject having multiple myeloma (MM) with a bispecific antibody that binds to Fc receptor homolog 5 (FcRH5) and cluster of differentiation 3 (CD3), the method comprising: (a) determining the level of a T cell proliferation marker in a biological sample obtained from the subject at a time point after administration of the bispecific antibody; (b) comparing the level of the T cell proliferation marker in the biological sample to a reference level, wherein if the level of the T cell proliferation marker in the biological sample is increased relative to the reference level, the subject is identified as a subject responsive to the bispecific antibody; and (c) if the level of the T cell proliferation marker is increased relative to the reference level, continuing to administer the bispecific antibody to the subject.

[0008] In another aspect, the invention features a method of treating a subject having MM with a bispecific antibody that binds to FcRH5 and CD3, the method comprising: (a) determining whether a biological sample obtained from the subject at a time point after administration of the bispecific antibody is positive for the proliferation marker Ki-67 (MKI67 + ) the number of T cells; (b) the MKI67 in biological samples + The number of T cells is compared to a reference number, where the MKI67 in the biological sample is higher relative to the reference number. + If the number of T cells increases, the subject is identified as a subject that responds to the bispecific antibody; and (c) if the number of MKI67 in the biological sample of the subject is increased relative to the reference number, + If the number of T cells increases, then the bispecific antibody continues to be administered to the subject.

[0009] In another aspect, the invention features a method of monitoring the response of a subject having MM to treatment with a bispecific antibody that binds to FcRH5 and CD3, the method comprising: (a) determining the level of a T cell proliferation marker in a biological sample obtained from the subject at a time point after administration of the bispecific antibody; and (b) comparing the level of the T cell proliferation marker in the biological sample to a reference level, wherein an increase in the level of the T cell proliferation marker in the biological sample relative to the reference level identifies the subject as a subject responsive to the bispecific antibody, thereby monitoring the subject's response to treatment with the bispecific antibody.

[0010] In another aspect, the invention features a method of monitoring the response of a subject having MM to treatment with a bispecific antibody that binds to FcRH5 and CD3, the method comprising: (a) determining the level of MKI67 in a biological sample obtained from the subject at a time point after administration of the bispecific antibody; + T cell count; and (b) MKI67 in biological samples + The number of T cells is compared to a reference number, where the MKI67 in the biological sample is higher relative to the reference number. + If the number of T cells increases, the subject is identified as a subject that has responded to the bispecific antibody, thereby monitoring the subject's response to treatment with the bispecific antibody.

[0011] In another aspect, the invention features a method for assessing a therapeutic response of a subject having MM to treatment with a bispecific antibody that binds to FcRH5 and CD3, the method comprising: (a) determining the level of a T cell proliferation marker in a biological sample obtained from the subject at a time point after administration of the bispecific antibody; and (b) maintaining, adjusting, or stopping treatment of the subject based on a comparison of the level of the T cell proliferation marker in the biological sample to a reference level, wherein a change in the level of the T cell proliferation marker in the biological sample compared to the reference level indicates a response to treatment with the bispecific antibody.

[0012] In another aspect, the invention features a method for assessing a therapeutic response of a subject having MM to treatment with a bispecific antibody that binds to FcRH5 and CD3, the method comprising: (a) determining the level of MKI67 in a biological sample obtained from the subject at a time point after administration of the bispecific antibody; + T cell count; and (b) based on MKI67 in biological samples + T cells in the biological sample are compared to a reference number to maintain, adjust or stop treatment of the subject, wherein the MKI67 in the biological sample is compared to the reference number. + Changes in the number of T cells indicate a response to treatment with the bispecific antibody.

[0013] In another aspect, the invention features a bispecific antibody that binds to FcRH5 and CD3 for use in treating a subject with MM, the treatment comprising: (a) determining the level of a T cell proliferation marker in a biological sample obtained from the subject at a time point after administration of the bispecific antibody; (b) comparing the level of the T cell proliferation marker in the biological sample to a reference level, wherein if the level of the T cell proliferation marker in the biological sample is increased relative to the reference level, the subject is identified as a subject responsive to the bispecific antibody; and (c) if the level of the T cell proliferation marker is increased relative to the reference level, continuing to administer the bispecific antibody to the subject.

[0014] In another aspect, the invention features a bispecific antibody that binds to FcRH5 and CD3 for use in treating a subject with MM, the treatment comprising: (a) determining whether a biological sample obtained from the subject at a time point after administration of the bispecific antibody is positive for the proliferation marker Ki-67 (MKI67 + ) the number of T cells; (b) the MKI67 in biological samples + The number of T cells is compared to a reference number, where the MKI67 in the biological sample is higher relative to the reference number. +If the number of T cells increases, the subject is identified as a subject that responds to the bispecific antibody; and (c) if the number of MKI67 in the biological sample of the subject is increased relative to the reference number, + If the number of T cells increases, then the bispecific antibody continues to be administered to the subject.

[0015] In another aspect, the invention features a bispecific antibody that binds to FcRH5 and CD3 for use in the treatment of a subject with MM, the treatment comprising the step of monitoring the subject's response to the treatment, the monitoring comprising: (a) determining the level of a T cell proliferation marker in a biological sample obtained from the subject at a time point after administration of the bispecific antibody; and (b) comparing the level of the T cell proliferation marker in the biological sample to a reference level, wherein an increase in the level of the T cell proliferation marker in the biological sample relative to the reference level identifies the subject as a subject responsive to the bispecific antibody, thereby monitoring the subject's response to treatment with the bispecific antibody.

[0016] In another aspect, the invention is characterized by a bispecific antibody bound to FcRH5 and CD3 for use in the treatment of a subject with MM, the treatment includes the step of monitoring the subject's response to treatment, the monitoring includes: (a) determining MKI67 in a biological sample obtained from the subject at a time point after administration of the bispecific antibody + T cell count; and (b) MKI67 in biological samples + The number of T cells is compared to a reference number, where the MKI67 in the biological sample is higher relative to the reference number. + If the number of T cells increases, the subject is identified as a subject that has responded to the bispecific antibody, thereby monitoring the subject's response to treatment with the bispecific antibody.

[0017] In another aspect, the invention features a bispecific antibody that binds to FcRH5 and CD3 for use in the treatment of a subject having MM, the treatment comprising the step of assessing the subject's response to the treatment, the assessment comprising: (a) determining the level of a T cell proliferation marker in a biological sample obtained from the subject at a time point after administration of the bispecific antibody; and (b) maintaining, adjusting, or stopping the subject's treatment based on a comparison of the level of the T cell proliferation marker in the biological sample to a reference level, wherein a change in the level of the T cell proliferation marker in the biological sample compared to the reference level indicates a response to treatment with the bispecific antibody.

[0018] In another aspect, the invention is characterized by a bispecific antibody bound to FcRH5 and CD3 for use in the treatment of a subject with MM, the treatment includes the step of evaluating the subject's response to treatment, the assessment comprising: (a) determining MKI67 in a biological sample obtained from the subject at a time point after administration of the bispecific antibody + T cell count; and (b) based on MKI67 in biological samples + T cells in the biological sample are compared to a reference number to maintain, adjust or stop treatment of the subject, wherein the MKI67 in the biological sample is compared to the reference number. + Changes in the number of T cells indicate a response to treatment with the bispecific antibody.

[0019] In some aspects, (a) if the level of T cell proliferation markers in the biological sample increases relative to the reference level, the subject responds to treatment and the treatment is maintained; or (b) if the level of T cell proliferation markers in the biological sample is the same or reduced relative to the reference level, the subject does not respond to treatment and the treatment is adjusted or stopped.

[0020] In some aspects, (a) if MKI67 in a biological sample is + If the number of MKI67 cells in the biological sample increases relative to the reference number, the subject has responded to the treatment and the treatment is maintained; or (b) if the number of MKI67 cells in the biological sample increases relative to the reference number, the subject has responded to the treatment and the treatment is maintained; + If the number of cells remains the same or decreases, the subject is not responding to treatment and treatment is adjusted or stopped.

[0021] In some aspects, the method further comprises administering the bispecific antibody to the subject.

[0022] In some aspects, administration of the bispecific antibody is performed with a dosing regimen including: (a) a first dosage cycle, wherein the first dosage cycle comprises at least a first dose (C1D1) and a second dose (C1D2) of the bispecific antibody; and (b) a second dosage cycle, wherein the second dosage cycle comprises a single dose (C2D1) of the bispecific antibody.

[0023] In some aspects, the time point after administration of the bispecific antibody is before C2D1.

[0024] In some aspects: (a) C1D1 is between about 0.5 mg and about 19.9 mg; (b) C1D2 is between about 20 mg and about 600 mg; and (c) C2D1 is between about 20 mg and about 600 mg.

[0025] In some aspects: (a) C1D1 is between about 1.2 mg and about 10.8 mg; (b) C1D2 is between about 80 mg and about 300 mg; and (c) C2D1 is between about 80 mg and about 300 mg.

[0026] In some aspects: (a) C1D1 is about 3.6 mg; (b) C1D2 is about 198 mg; and (c) C2D1 is about 198 mg.

[0027] In some aspects, the length of the first dosing cycle and the second dosing cycle is 21 days.

[0028] In some aspects, the dosing regimen includes administering C1D1 and C1D2 to the subject on or about day 1 and day 8, respectively, of a first dosing cycle, and administering C2D1 on or about day 1 of a second dosing cycle.

[0029] In some aspects, the dosing regimen includes one or more additional dosing cycles.

[0030] In some aspects, the dosing regimen comprises administering the bispecific antibody to the subject on or about day 1 of each of the additional dosing cycles.

[0031] In some aspects, the one or more additional dosing cycles include: (a) a third dosing cycle, wherein the third dosing cycle includes a single dose of the bispecific antibody (C3D1); and / or (b) a fourth dosing cycle, wherein the fourth dosing cycle includes a single dose of the bispecific antibody (C4D1).

[0032] In some aspects, the time point after administration of the bispecific antibody is before C3D1 and / or C4D1.

[0033] In some aspects, administration of the bispecific antibody is performed with a dosing regimen comprising: (a) a first dosing cycle, wherein the first dosing cycle comprises at least a first dose (C1D1), a second dose (C1D2), and a third dose (C1D3) of the bispecific antibody; and (b) a second dosing cycle, wherein the second dosing cycle comprises a single dose (C2D1) of the bispecific antibody.

[0034] In some aspects, the time point after administration of the bispecific antibody is before C2D1.

[0035] In some aspects: (a) C1D1 is between about 0.01 mg and about 2.9 mg; (b) C1D2 is between about 3 mg and about 19.9 mg; (c) C1D3 is between about 20 mg and about 600 mg; and (d) C2D1 is between about 20 mg and about 600 mg.

[0036] In some aspects: (a) C1D1 is between about 0.2 mg and about 0.4 mg; (b) C1D2 is between about 3.2 mg and about 10 mg; (c) C1D3 is between about 80 mg and about 300 mg; and (d) C2D1 is between about 80 mg and about 300 mg.

[0037] In some aspects: (a) C1D1 is about 0.3 mg; (b) C1D2 is about 3.6 mg; (c) C1D3 is about 160 mg; and (d) C2D1 is about 160 mg.

[0038] In some aspects, the length of the first dosing cycle and the second dosing cycle is 21 days.

[0039] In some aspects, the dosing regimen comprises administering C1D1, C1D2, and C1D3 to the subject on or about days 1, 8, and 15, respectively, of a first dosing cycle, and administering C2D1 on or about day 1 of a second dosing cycle.

[0040] In some aspects, the dosing regimen includes one or more additional dosing cycles.

[0041] In some aspects, the dosing regimen comprises administering the bispecific antibody to the subject on or about day 1 of each of the additional dosing cycles.

[0042] In some aspects, the one or more additional dosing cycles include: (a) a third dosing cycle, wherein the third dosing cycle includes a single dose of the bispecific antibody (C3D1); and / or (b) a fourth dosing cycle, wherein the fourth dosing cycle includes a single dose of the bispecific antibody (C4D1).

[0043] In some aspects, the time point after administration of the bispecific antibody is before C3D1 and / or C4D1.

[0044] In some aspects, the T cell proliferation marker is the proliferation marker Ki-67 (MKI67).

[0045] In some aspects, the level of a T cell proliferation marker is a protein level.

[0046] In some aspects, protein levels are detected by flow cytometry (FC), Western blot, enzyme-linked immunosorbent assay (ELISA), mass spectrometry (MS), immunofluorescence (IF), or immunohistochemistry (IHC).

[0047] In some aspects, protein levels are detected using an MKI67 antibody.

[0048] In some aspects, the anti-MKI67 antibody is a monoclonal Ki-67 or MIB-1 antibody.

[0049] In some aspects, the level of the T cell proliferation marker is the mRNA level of MKI67.

[0050] In some aspects, mRNA levels are detected by polymerase chain reaction (PCR), reverse transcription-PCR (RT-PCR), quantitative-PCR (qPCR), microarray analysis, Northern blot, or RNA sequencing.

[0051] In some aspects, T cell proliferation markers are detected in T cells.

[0052] In some aspects, the T cell is MKI67 + .

[0053] In some aspects, the reference level is the level of a T cell proliferation marker determined in a biological sample obtained from the subject prior to administering the bispecific antibody to the subject.

[0054] In some aspects, the reference level is the level of MKI67 determined in a biological sample obtained from the subject prior to administering the bispecific antibody to the subject.

[0055] In some aspects, MKI67 + T cells were detected by FC, Western blot, ELISA, MS, IF or IHC.

[0056] In some aspects, MKI67 + T cells were detected using MKI67 antibody.

[0057] In some aspects, the anti-MKI67 antibody is a monoclonal Ki-67 or MIB-1 antibody.

[0058] In some aspects, the reference amount is MKI67 determined in a biological sample obtained from the subject prior to administering the bispecific antibody to the subject. + The number of T cells.

[0059] In some aspects, the T cells are cluster of differentiation 8 (CD8) positive (CD8 + ).

[0060] In some aspects, the T cells are granzyme B (Gzb) positive (Gzb+).

[0061] In some aspects, the biological sample is blood, serum, or plasma.

[0062] In some aspects, the bispecific antibody comprises: an anti-FcRH5 arm comprising a first binding domain comprising the following six hypervariable regions (HVRs): (a) HVR-H1 comprising the amino acid sequence of RFGVH (SEQ ID NO: 1); (b) HVR-H2 comprising the amino acid sequence of VIWRGGSTDYNAAFVS (SEQ ID NO: 2); (c) HVR-H3 comprising the amino acid sequence of HYYGSSDYALDN (SEQ ID NO: 3); (d) HVR-L1 comprising the amino acid sequence of KASQDVRNLVV (SEQ ID NO: 4); (e) HVR-L2 comprising the amino acid sequence of SGSYRYS (SEQ ID NO: 5); and (f) HVR-L3 comprising the amino acid sequence of QQHYSPPYT (SEQ ID NO: 6).

[0063] In some aspects, the bispecific antibody comprises: an anti-FcRH5 arm comprising a first binding domain, the first binding domain comprising: (a) a heavy chain variable (VH) domain comprising an amino acid sequence having at least 95% sequence identity to the amino acid sequence of SEQ ID NO:7; (b) a light chain variable (VL) domain comprising an amino acid sequence having at least 95% sequence identity to the amino acid sequence of SEQ ID NO:8; or (c) a VH domain as in (a) and a VL domain as in (b).

[0064] In some aspects, the first binding domain comprises: a VH domain comprising the amino acid sequence of SEQ ID NO:7; and a VL domain comprising the amino acid sequence of SEQ ID NO:8.

[0065] In some aspects, the bispecific antibody comprises: an anti-CD3 arm comprising a second binding domain comprising the following six HVRs: (a) HVR-H1 comprising the amino acid sequence of SYYIH (SEQ ID NO:9); (b) HVR-H2 comprising the amino acid sequence of WIYPENDNTKYNEKFKD (SEQ ID NO:10); (c) HVR-H3 comprising the amino acid sequence of DGYSRYYFDY (SEQ ID NO:11); (d) HVR-L1 comprising the amino acid sequence of KSSQSLLNSRTRKNYLA (SEQ ID NO:12), (e) HVR-L2 comprising the amino acid sequence of WTSTRKS (SEQ ID NO:13); and (f) HVR-L3 comprising the amino acid sequence of KQSFILRT (SEQ ID NO:14).

[0066] In some aspects, the bispecific antibody comprises: an anti-CD3 arm comprising a second binding domain, the second binding domain comprising: (a) a VH domain comprising an amino acid sequence having at least 95% sequence identity with the amino acid sequence of SEQ ID NO: 15; (b) a VL domain comprising an amino acid sequence having at least 95% sequence identity with the amino acid sequence of SEQ ID NO: 16; or (c) a VH domain as in (a) and a VL domain as in (b).

[0067] In some aspects, the second binding domain comprises: a VH domain comprising the amino acid sequence of SEQ ID NO:15; and a VL domain comprising the amino acid sequence of SEQ ID NO:16.

[0068] In some aspects, the bispecific antibody comprises: an anti-FcRH5 arm comprising a heavy chain polypeptide (H1) and a light chain polypeptide (L1); and an anti-CD3 arm comprising a heavy chain polypeptide (H2) and a light chain polypeptide (L2), and wherein: (a) H1 comprises the amino acid sequence of SEQ ID NO:35; (b) L1 comprises the amino acid sequence of SEQ ID NO:36; (c) H2 comprises the amino acid sequence of SEQ ID NO:37; and (d) L2 comprises the amino acid sequence of SEQ ID NO:38.

[0069] In some aspects, the bispecific antibody is cevostamab.

[0070] In some aspects, the bispecific antibody comprises an aglycosylation site mutation.

[0071] In some aspects, the aglycosylation site mutation reduces the effector function of the bispecific antibody.

[0072] In some aspects, the deglycosylation site mutation is a substitution mutation.

[0073] In some aspects, the bispecific antibody comprises a substitution mutation in the Fc region that reduces effector function.

[0074] In some aspects, the bispecific antibodies are monoclonal antibodies.

[0075] In some aspects, the bispecific antibodies are humanized antibodies.

[0076] In some aspects, the bispecific antibodies are chimeric antibodies.

[0077] In some aspects, the bispecific antibody is an antibody fragment that binds FcRH5 and CD3.

[0078] In some aspects, the antibody fragment is selected from the group consisting of: Fab, Fab'-SH, Fv, scFv and (Fab') 2 Fragment.

[0079] In some aspects, the bispecific antibodies are full-length antibodies.

[0080] In some aspects, the bispecific antibody is an IgG antibody.

[0081] In some aspects, the IgG antibody is IgG 1 Antibody.

[0082] In some aspects, the bispecific antibody comprises one or more heavy chain constant domains, wherein the one or more heavy chain constant domains are selected from a first CH1 (CH1 1 ) domain, the first CH2 (CH2 1 ) domain, the first CH3 (CH3 1 ) domain, the second CH1 (CH1 2 ) domain, the second CH2 (CH2 2 ) domain and the second CH3 (CH3 2 ) domain.

[0083] In some aspects, at least one of the one or more heavy chain constant domains is paired with another heavy chain constant domain.

[0084] In some aspects, CH3 1 and CH3 2 The domains each contain a protrusion or cavity, and wherein CH3 1 The protrusion or cavity in the domain can be located at the CH3 2 In a cavity or protrusion in a domain.

[0085] In some aspects, CH3 1 Domain and CH3 2 The domains meet at the interface between the protrusion and the cavity.

[0086] In some aspects, CH2 1 and CH2 2 The domains each contain a protrusion or cavity, and wherein CH2 1 The protrusion or cavity in the domain can be located at the CH2 2 In a cavity or protrusion in a domain.

[0087] In some aspects, CH2 1 and CH2 2 The domains meet at the interface between the protrusion and the cavity.

[0088] In some aspects, the anti-FcRH5 arm comprises a protrusion and the anti-CD3 arm comprises a cavity.

[0089] In some aspects, the CH3 domain of the anti-FcRH5 arm comprises a protrusion comprising a T366W amino acid substitution mutation (EU numbering), and the CH3 domain of the anti-CD3 arm comprises a cavity comprising T366S, L368A, and Y407V amino acid substitution mutations (EU numbering).

[0090] In some aspects, the bispecific antibody is administered to a subject as a monotherapy.

[0091] In some aspects, the bispecific antibody is administered to a subject as a combination therapy.

[0092] In some aspects, the bispecific antibody and one or more additional therapeutic agents are administered to a subject simultaneously.

[0093] In some aspects, the bispecific antibody is administered to the subject prior to administration of one or more additional therapeutic agents.

[0094] In some aspects, the bispecific antibody is administered to the subject after administration of one or more additional therapeutic agents.

[0095] In some aspects, the one or more additional therapeutic agents comprises an effective amount of tocilizumab.

[0096] In some aspects, tocilizumab is administered to the subject by intravenous infusion.

[0097] In some aspects: (a) the subject weighs ≥100 kg and tocilizumab is administered to the subject at a dose of 800 mg; (b) the subject weighs ≥30 kg and <100 kg and tocilizumab is administered to the subject at a dose of 8 mg / kg; or (c) the subject weighs <30 kg and tocilizumab is administered to the subject at a dose of 12 mg / kg.

[0098] In some aspects, tocilizumab is administered to the subject 2 hours prior to administration of the bispecific antibody.

[0099] In some aspects, the one or more additional therapeutic agents include an effective amount of an immunomodulatory drug (IMiD), daratumumab, or a B-cell maturation antigen (BCMA)-directed therapy.

[0100] In some aspects, the bispecific antibody is administered to the subject by intravenous infusion.

[0101] In some aspects, the bispecific antibody is administered to the subject subcutaneously.

[0102] In some aspects, the subject experiences a cytokine release syndrome (CRS) event, and the method further comprises treating symptoms of the CRS event while suspending treatment with the bispecific antibody.

[0103] In some aspects, the method further comprises administering to the subject an effective amount of tocilizumab to treat the CRS event.

[0104] In some aspects, tocilizumab is administered intravenously to the subject as a single dose of about 8 mg / kg.

[0105] In some aspects, the CRS event does not resolve, or worsens, within 24 hours of treating symptoms of the CRS event, and the method further comprises administering one or more additional doses of tocilizumab to the subject to manage the CRS event.

[0106] In some aspects, one or more additional doses of tocilizumab are administered intravenously to the subject at a dose of about 8 mg / kg.

[0107] In some aspects, the one or more additional therapeutic agents comprises an effective amount of a corticosteroid.

[0108] In some aspects, the corticosteroid is administered intravenously to the subject.

[0109] In some aspects, the corticosteroid is methylprednisolone.

[0110] In some aspects, methylprednisolone is administered at a dose of about 80 mg.

[0111] In some aspects, the corticosteroid is dexamethasone.

[0112] In some aspects, dexamethasone is administered at a dose of about 20 mg.

[0113] In some aspects, the one or more additional therapeutic agents comprises an effective amount of acetaminophen or paracetamol.

[0114] In some aspects, acetaminophen or paracetamol is administered in a dose of between about 500 mg to about 1000 mg.

[0115] In some aspects, acetaminophen or paracetamol is orally administered to the subject.

[0116] In some aspects, the one or more additional therapeutic agents comprises an effective amount of diphenhydramine.

[0117] In some aspects, diphenhydramine is administered in a dose of between about 25 mg to about 50 mg.

[0118] In some aspects, diphenhydramine is administered orally to the subject.

[0119] In some aspects, the MM is relapsed or refractory (R / R) MM.

[0120] In some aspects, the individual has received at least three prior lines of treatment for MM.

[0121] In some aspects, the individual has received at least four prior lines of treatment for MM.

[0122] In some aspects, the individual has been exposed to a prior treatment comprising a proteasome inhibitor, an IMiD, and / or an anti-CD38 therapeutic.

[0123] In some aspects, the proteasome inhibitor is bortezomib, carfilzomib, or ixazomib.

[0124] In some aspects, the IMiD is thalidomide, lenalidomide, or pomalidomide.

[0125] In some aspects, the anti-CD38 therapeutic agent is an anti-CD38 antibody.

[0126] In some aspects, the anti-CD38 antibody is daratumumab, MOR202, or isatuximab.

[0127] In some aspects, the anti-CD38 antibody is daratumumab.

[0128] In some aspects, the individual has been exposed to prior treatments including: anti-SLAMF7 therapeutics, nuclear export inhibitors, histone deacetylase (HDAC) inhibitors, autologous stem cell transplantation (ASCT), bispecific antibodies, antibody-drug conjugates (ADC), CAR-T cell therapy, or BCMA-directed therapy.

[0129] In some aspects, the anti-SLAMF7 therapeutic agent is an anti-SLAMF7 antibody.

[0130] In some aspects, the anti-SLAMF7 antibody is elotuzumab.

[0131] In some aspects, the nuclear export inhibitor is selinexor.

[0132] In some aspects, the HDAC inhibitor is panobinostat.

[0133] In some aspects, the BCMA-directed therapy is an antibody-drug conjugate that targets BCMA. BRIEF DESCRIPTION OF THE DRAWINGS

[0134] Figure 1Schematic diagram showing the dose escalation schedule for Group A (single-step dose escalation group) and Group B (multi-step dose escalation group) of the Phase I dose escalation study of GO39775. C: cycle; D: day; Q: every.

[0135] Figure 2A Schematic structure of sivostatin.

[0136] Figure 2B Schematic diagram illustrating the mode of action of silvostomomab.

[0137] Figure 2C A general timeline for a single-step dosing regimen and whole blood sample collection is shown.

[0138] Figure 3A Schematic diagram of the framework for unbiased clustering of flow cytometry data.

[0139] Figure 3B Figure 2 is a representative difference area plot used to determine the number of clusters (k). This plot allows the user to determine the relative increase in consensus and determine the k at which there is no significant increase in the area under the cumulative distribution function (CDF) curve.

[0140] Figure 3C Representative heatmaps used to visualize the distribution of markers for clusters.

[0141] Figure 3D is a representative uniform manifold approximation and projection (UMAP) for the clusters.

[0142] Figure 3E Representative volcano plots visualizing statistical significance (p-value) versus magnitude of change (fold change) obtained from differential abundance and expression analysis.

[0143] Figure 4A Granzyme B positive (Gzb) was shown using FlowSOM + ) Box plot of the expression of the proliferation marker Ki-67 (MKI67) in cluster of differentiation 8 (CD8) T cell clusters.

[0144] Figure 4B To show MKI67 positivity from traditional manual gating (MKI67 + )CD8 positive (CD8 + ) Box plot of T cell abundance.

[0145] Figure 4C Shown are UMAP (top) and box plots (bottom) from Cellular Indexing of Transcriptomes and Epitopes by Sequencing (CITE-seq) analysis demonstrating increased expression of MKI67 21 days after treatment.

[0146] Figure 5Ais a heat map from FlowSOM clustering showing three cluster of differentiation 4 positive (CD4 + )T cell clusters.

[0147] Figure 5B Showing CD4 in CITE-seq data + CD25 protein expression in T cells.

[0148] Figure 5C UMAP re-clustering of CITE-seq Tregs is shown.

[0149] Figure 5D A set of graphs showing that re-clustering of CITE-seq Tregs yields similar CD25 patterns.

[0150] Fig. 6A The heatmap (top) and corresponding UMAP (bottom) from FlowSOM clustering show that 2 human leukocyte antigen DR positive (HLA-DR + ) Cluster of differentiation 19 positive (CD19 + )B cell clusters.

[0151] Figure 6B For UMAP, it is shown that circulating tumor cells can be distinguished from B cells in CITE-seq data.

[0152] Figure 6C is a set of graphs showing that tumor cells have lower CD19 expression (top) but higher FcRH5 expression (bottom). DETAILED DESCRIPTION

[0153] I. Definitions

[0154] As used herein, the term "about" refers to the common error range for the corresponding value that is readily known to those skilled in the art. Reference herein to "about" a value or parameter includes (and describes) aspects relating to the value or parameter itself.

[0155] It should be understood that aspects of the invention described herein include "comprising," "consisting of," and "consisting essentially of" aspects.

[0156] As used herein, the term "FcRH5" or "crystallizable fragment receptor-like 5" refers to any native FcRH5 from any vertebrate source, including mammals such as primates (e.g., humans) and rodents (e.g., mice and rats), unless otherwise indicated, and encompasses "full-length," unprocessed FcRH5, as well as any form of FcRH5 produced by processing in cells. The term also encompasses naturally occurring variants of FcRH5, including, for example, splice variants or allelic variants. FcRH5 includes, for example, human FcRH5 protein (UniProtKB / Swiss-ProtID: Q96RD9.3), which is 977 amino acids in length.

[0157] The terms "anti-FcRH5 antibody" and "antibody that binds to FcRH5" refer to an antibody that is capable of binding to FcRH5 with sufficient affinity such that the antibody is useful as a diagnostic and / or therapeutic agent targeting FcRH5. In one embodiment, the extent of binding of the anti-FcRH5 antibody to an unrelated, non-FcRH5 protein is less than about 10% of the extent of binding of the antibody to FcRH5, as measured, for example, by radioimmunoassay (RIA). In certain embodiments, the antibody that binds to FcRH5 has a binding affinity of ≤1 μM, ≤250 nM, ≤100 nM, ≤15 nM, ≤10 nM, ≤6 nM, ≤4 nM, ≤2 nM, ≤1 nM, ≤0.1 nM, ≤0.01 nM, or ≤0.001 nM (e.g., 10 -8 M or less, for example, 10 -8 M to 10 -13 M, for example, 10 -9 M to 10 -13 The dissociation constant (K D In certain embodiments, the anti-FcRH5 antibody binds to an epitope of FcRH5 that is conserved among FcRH5 from different species.

[0158] Unless otherwise indicated, the term "cluster of differentiation 3" or "CD3" as used herein refers to any native CD3 from any vertebrate source, including, for example, primates (e.g., humans) and rodents (e.g., mice and rats), including, for example, CD3ε, CD3γ, CD3α, and CD3β chains. The term encompasses "full-length" unprocessed CD3 (e.g., unprocessed or unmodified CD3ε or CD3γ), as well as any form of CD3 produced by processing in cells. The term also encompasses naturally occurring variants of CD3, including, for example, splice variants or allelic variants. CD3 includes, for example, a human CD3ε protein (NCBI RefSeq No. NP_000724) having a length of 207 amino acids and a human CD3γ protein (NCBI RefSeq No. NP_000064) having a length of 182 amino acids.

[0159] The terms "anti-CD3 antibody" and "antibody that binds to CD3" refer to an antibody that is capable of binding to CD3 with sufficient affinity such that the antibody can be used as a diagnostic and / or therapeutic agent targeting CD3. In one embodiment, the extent of binding of the anti-CD3 antibody to an unrelated, non-CD3 protein is less than about 10% of the extent of binding of the antibody to CD3, as measured, for example, by a radioimmunoassay (RIA). In certain embodiments, the antibody that binds to CD3 has a binding affinity of ≤1 μM, ≤250 nM, ≤100 nM, ≤15 nM, ≤10 nM, ≤5 nM, ≤1 nM, ≤0.1 nM, ≤0.01 nM, or ≤0.001 nM (e.g., 10 -8 M or smaller, e.g. 10 -8 M to 10 -13 M, for example 10 -9 M to 10 -13 The dissociation constant (K D In certain embodiments, the anti-CD3 antibody binds to an epitope of CD3 that is conserved in CD3 from different species.

[0160] For the purposes of this article, "Sivositumab" is also referred to as BFCR4350A or RO7187797, which is an Fc-engineered, humanized, full-length aglycosylated IgG1κ T cell-dependent bispecific antibody (TDB) that binds to FcRH5 and CD3 and comprises an anti-FcRH5 arm comprising a heavy chain polypeptide sequence of SEQ ID NO:35 and a light chain polypeptide sequence of SEQ ID NO:36, and an anti-CD3 arm comprising a heavy chain polypeptide sequence of SEQ ID NO:37 and a light chain polypeptide sequence of SEQ ID NO:38. Sivositumab contains an amino acid substitution of threonine to tryptophan at position 366 of the anti-FcRH5 arm (T366W) using EU numbering of amino acid residues in the Fc region, and three amino acid substitutions on the heavy chain of the anti-CD3 arm (Y407V, T366S, and L368A) using EU numbering of amino acid residues in the Fc region (a substitution of tyrosine to valine at position 407, a substitution of threonine to serine at position 366, and a substitution of leucine to alanine at position 368) to drive heterodimerization of the two arms (half antibody). Sivositumab also contains an amino acid substitution (asparagine to glycine) at position 297 on each heavy chain (N297G) using EU numbering of amino acid residues in the Fc region, which results in a minimal aglycosylated antibody that binds to Fc (Fcγ) receptors and thereby prevents Fc effector function. Sivodara is also described in the following document: WHO Drug Information (International Nonproprietary Names of Drug Substances), Proposed INN: List 84, Volume 34, Issue 3, published in 2020 (see page 701).

[0161] The term "antibody" herein is used in the broadest sense and covers various antibody structures, including but not limited to monoclonal antibodies, polyclonal antibodies, multispecific antibodies (e.g., bispecific antibodies) and antibody fragments (e.g., bis-Fab), so long as they exhibit the desired antigen-binding activity.

[0162] "Affinity" refers to the strength of the sum of non-covalent interactions between a single binding site of a molecule (e.g., an antibody) and its binding partner (e.g., an antigen). Unless otherwise indicated, as used herein, "binding affinity" refers to intrinsic binding affinity, which reflects a 1:1 interaction between members of a binding pair (e.g., an antibody and an antigen). The affinity of a molecule X for its partner Y can be generally described by the dissociation constant (K D ) represents. Affinity can be measured by conventional methods known in the art, including those described herein. Specific illustrative and exemplary aspects for measuring binding affinity are described below.

[0163] An "affinity matured" antibody is one with one or more alterations in one or more hypervariable regions (HVRs) which result in an improvement in the affinity of the antibody for antigen, compared to a parent antibody which does not possess such alterations.

[0164] The terms "full length antibody," "intact antibody," and "whole antibody" are used interchangeably herein to refer to an antibody having a structure substantially similar to a native antibody structure or having heavy chains that contain an Fc region as defined herein.

[0165] "Antibody fragment" refers to a molecule other than an intact antibody that contains a portion of an intact antibody and binds to the antigen to which the intact antibody binds. Examples of antibody fragments include, but are not limited to: bis-Fab; Fv; Fab; Fab, Fab'-SH; F(ab') 2 ; diabodies; linear antibodies; single-chain antibody molecules (e.g., scFv, ScFab); and multispecific antibodies formed from antibody fragments.

[0166] "Single domain antibody" refers to an antibody fragment that contains all or part of the heavy chain variable domain or all or part of the light chain variable domain of an antibody. In certain aspects, a single domain antibody is a human single domain antibody (see, e.g., U.S. Patent No. 6,248,516B1). Examples of single domain antibodies include, but are not limited to, VHH.

[0167] The "Fab" fragment is an antigen-binding fragment produced by papain digestion of an antibody and consists of an intact L chain as well as the variable region domain of the H chain (VH) and the first constant domain (CH1) of one heavy chain. Papain digestion of an antibody produces two identical Fab fragments. Pepsin treatment of an antibody produces a single large F(ab') 2 A fragment that is roughly equivalent to two Fab fragments connected by disulfide bonds with divalent antigen binding activity and still capable of cross-linking antigens. The difference between the Fab fragment and the Fab fragment is that the Fab fragment has some residues added to the carboxyl terminus of the CH1 domain, which contain one or more cysteines from the antibody hinge region. Fab'-SH is the designation herein for Fab' in which the cysteine ​​residues of the constant domains carry free thiol groups. F(ab') 2 Antibody fragments originally were produced as pairs of Fab' fragments which have hinge cysteines between them.Other chemical couplings of antibody fragments are also known.

[0168] "Fv" consists of a tight, non-covalently associated dimer of a heavy chain variable region domain and a light chain variable region domain. Six hypervariable loops (3 loops each from the H chain and L chain) are generated by the folding of these two domains, which contribute amino acid residues to achieve antigen binding and provide the antibody with antigen binding specificity. However, even a single variable domain (or half of an Fv, containing only three CDRs specific for an antigen) has the ability to recognize and bind to an antigen, although its affinity is often lower than that of the complete binding site.

[0169] The term "Fc region" herein is used to define the C-terminal region of an immunoglobulin heavy chain, which includes a native sequence Fc region and a variant Fc region. Although the boundaries of an immunoglobulin heavy chain Fc region may vary, the human IgG heavy chain Fc region is generally defined as extending from the amino acid residue at position Cys226 or from Pro230 to the carboxyl terminus of the heavy chain. The C-terminal lysine in the Fc region (residue 447 according to the EU numbering system) can be removed in, for example, the production or purification process of an antibody or by recombinantly designing a nucleic acid encoding an antibody heavy chain. Therefore, the composition of a complete antibody can include an antibody population removing all Lys447 residues, an antibody population not removing Lys447 residues, and an antibody population with and without an antibody mixture containing Lys447 residues.

[0170] A "functional Fc region" possesses the "effector functions" of a native sequence Fc region. Exemplary "effector functions" include C1q binding; CDC; Fc receptor binding; ADCC; phagocytosis; downregulation of cell surface receptors (e.g., B cell receptor; BCR), etc. Such effector functions generally require an Fc region in combination with a binding domain (e.g., an antibody variable domain), and can be assessed using various assays such as those disclosed in the definitions herein.

[0171] A "native sequence Fc region" comprises an amino acid sequence identical to the amino acid sequence of an Fc region found in nature. Native sequence human Fc regions include native sequence human IgG1 Fc regions (non-A and A allotypes); native sequence human IgG2 Fc regions; native sequence human IgG3 Fc regions; and native sequence human IgG4 Fc regions and naturally occurring variants thereof.

[0172] A "variant Fc region" comprises an amino acid sequence that differs from a native sequence Fc region by virtue of at least one amino acid modification, preferably one or more amino acid substitutions. Preferably, the variant Fc region has at least one amino acid substitution compared to the native sequence Fc region or the Fc region of a parent polypeptide, for example, from about one to about ten amino acid substitutions in the native sequence Fc region or the Fc region of a parent polypeptide, and preferably from about one to about five amino acid substitutions. The variant Fc regions described herein preferably have at least about 80% homology with the native sequence Fc region and / or with the Fc region of a parent polypeptide, preferably at least about 90% homology therewith, or preferably at least about 95% homology therewith.

[0173] As used herein, "Fc complex" refers to the CH3 domains of two Fc regions interacting together to form a dimer, or in certain aspects, two Fc regions interacting to form a dimer, wherein the cysteine ​​residues in the hinge region and / or the CH3 domains interact through bonds and / or forces (e.g., van der Waals forces, hydrophobic forces, hydrogen bonds, electrostatic forces, or disulfide bonds).

[0174] As used herein, "Fc component" refers to the hinge region, CH2 domain or CH3 domain of the Fc region.

[0175] The "hinge region" is generally defined as stretching from about residues 216 to 230 of IgG (EU numbering), from about residues 226 to 243 of IgG (Kabat numbering), or from about residues 1 to 15 of IgG (IMGT unique numbering).

[0176] The "lower hinge region" of an Fc region is generally defined as the stretch of residues immediately C-terminal to the hinge region, ie, residues 233 to 239 (EU numbering) of the Fc region.

[0177] A "variant Fc region" comprises an amino acid sequence that differs from a native sequence Fc region by virtue of at least one amino acid modification, preferably one or more amino acid substitutions. Preferably, the variant Fc region has at least one amino acid substitution compared to the native sequence Fc region or the Fc region of a parent polypeptide, for example, from about one to about ten amino acid substitutions in the native sequence Fc region or the Fc region of a parent polypeptide, and preferably from about one to about five amino acid substitutions. The variant Fc region described herein preferably has at least about 80% homology with the native sequence Fc region and / or with the Fc region of a parent polypeptide, and preferably has at least about 90% homology therewith, more preferably has at least about 95% homology therewith.

[0178] "Fc receptor" or "FcR" refers to a receptor that binds to the Fc region of an antibody. The preferred FcR is a native sequence human FcR. In addition, the preferred FcR is an FcR that binds to IgG antibodies (a gamma receptor), and includes receptors of the FcγRI, FcγRII, and FcγRIII subclasses, including allelic variants and alternatively spliced ​​forms of these receptors. FcγRII receptors include FcγRIIA ("activating receptor") and FcγRIIB ("inhibiting receptor"), which have similar amino acid sequences, the main difference being their cytoplasmic domains. The activating receptor FcγRIIA contains an immunoreceptor tyrosine-based activation motif (ITAM) in its cytoplasmic domain. The inhibitory receptor FcγRIIB contains an immunoreceptor tyrosine-based inhibition motif (ITIM) in its cytoplasmic domain (see Annu. Rev. Immunol. 15: 203-234 (1997) in review M.). FcRs are reviewed in Ravetch and Kinet, Annu. Rev. Immunol. 9: 457-492 (1991); Capel et al., Immunomethods 4: 25-34 (1994); and de Haas et al., J. Lab. Clin. Med. 126: 330-41 (1995). The term "FcR" herein encompasses other FcRs, including those to be identified in the future. The term also includes the neonatal receptor FcRn, which is responsible for the transfer of maternal IgG to the fetus (Guyer et al., J. Immunol. 117: 587 (1976) and Kim et al., J. Immunol. 24: 249 (1994)).

[0179] As described herein, the term "knob-into-hole" or "KnH" technology refers to a technique for guiding the pairing of two polypeptides together in vivo or in vitro by introducing a protrusion (knob) into one polypeptide and a cavity (hole) into the other polypeptide at their interactive interface. For example, KnH has been introduced into the Fc:Fc interaction interface, CL:CH1 interface, or VH / VL interface of antibodies (see, e.g., US2007 / 0178552, WO 96 / 027011, WO 98 / 050431, and Zhu et al. (1997) Protein Science 6:781-788). This is particularly useful for driving two different heavy chains to pair together during the preparation of multispecific antibodies. For example, a multispecific antibody having a KnH in its Fc region may further comprise a single variable domain connected to each Fc region, or further comprise different heavy chain variable domains paired with the same, similar or different light chain variable domains. KnH technology can also be used to pair together two different receptor extracellular domains or any other polypeptide sequences containing different target recognition sequences.

[0180] "Framework" or "FR" refers to the variable domain residues other than the hypervariable region (HVR) residues. The FR of the variable domain is usually composed of the following four FR domains: FR1, FR2, FR3 and FR4. Therefore, HVR and FR sequences usually appear in the following sequence in VH (or VL): FR1-H1 (L1)-FR2-H2 (L2)-FR3-H3 (L3)-FR4.

[0181] A "CH1 region" or "CH1 domain" comprises a stretch of residues extending from about residue 118 to residue 215 of IgG (EU numbering), from about residue 114 to residue 223 of IgG (Kabat numbering), or from about residue 1.4 to residue 121 of IgG (IMGT unique numbering) (Lefranc MP, Giudicelli V, Duroux P, Jabado-Michaloud J, Folch G, Aouinti S, Carillon E, Duvergey H, Houles A, Paysan-Lafosse T, Hadi-Saljoqi S, Sasorith S, Lefranc G, Kossida S. the international ImMunoGeneTics information 25years on. Nucleic Acids Res. 2015 Jan;43(Database Issue):D413-22).

[0182] The "CH2 domain" of the human IgG Fc region generally extends from about 244 to about 360 (Kabat numbering) of IgG, from about 231 to about 340 (EU numbering) of IgG, or from about 1.6 to about 125 (IGMT unique numbering) of IgG. The uniqueness of the CH2 domain is that it is not tightly paired with another domain. In contrast, two N-connected branched carbohydrate chains are between the two CH2 domains of the complete native IgG molecule. It is speculated that carbohydrates may provide alternatives for domain-domain pairing and help stabilize the CH2 domain. Burton, Molec. Immunol. 22: 161-206 (1985).

[0183] A “CH3 domain” comprises a stretch of residues extending C-terminally of the CH2 domain in the Fc region (i.e., from about amino acid residue 361 to about amino acid residue 478 of IgG (Kabat numbering), from about amino acid residue 341 to about amino acid residue 447 of IgG (EU numbering), or from about amino acid residue 1.4 to about amino acid residue 130 of IgG (IGMT unique numbering)).

[0184] The "CL domain" or "constant light domain" comprises a stretch of residues extending from the C-terminus of the light chain variable domain (VL). The light chain of an antibody may be a kappa (κ) ("Cκ") or a lambda (λ) ("Cλ") light chain region. The Cκ region typically extends from about residue 108 to residue 214 of IgG (Kabat or EU numbering) or from about residue 1.4 to residue 126 of IgG (IMGT unique numbering). The Cλ residues typically extend from about residue 107a to residue 215 (Kabt numbering) or from about residue 1.5 to residue 127 (IMGT unique numbering) (Lefranc MP, Giudicelli V, Duroux P, Jabado-Michaloud J, Folch G, Aouinti S, Carillon E, Duvergey H, Houles A, Paysan-Lafosse T, Hadi-Saljoqi S, Sasorith S, Lefranc G, Kossida S. the international ImMunoGeneTics information 25years on. Nucleic Acids Res. 2015 Jan;43(Database Issue):D413-22).

[0185] The light chain (LC) derived from any vertebrate can be assigned to one of two clearly distinct types, called kappa and lambda, based on the amino acid sequence of its constant domain. Immunoglobulins can be assigned to different classes or isotypes based on the amino acid sequence of their heavy chain constant domain (CH). There are five classes of immunoglobulins: IgA, IgD, IgE, IgG, and IgM have heavy chains called α, δ, γ, ε, and μ, respectively. The γ and α classes are further divided into subclasses based on relatively minor differences in CH sequence and function, for example, humans express the following subclasses: IgG1, IgG2, IgG3, IgG4, IgA1, and IgA2.

[0186] The term "chimeric" antibody refers to an antibody in which a portion of the heavy and / or light chain is derived from a particular source or species, while the remainder of the heavy and / or light chain is derived from a different source or species.

[0187] The "class" of an antibody refers to the type of constant domain or region possessed by the heavy chain of the antibody. There are five major classes of antibodies: IgA, IgD, IgE, IgG, and IgM, and some of these antibodies can be further divided into subclasses (isotypes), such as IgG 1 IgG 2 IgG 3 IgG 4 , IgA 1 and IgA 2 The heavy-chain constant domains that correspond to the different classes of immunoglobulins are called α, δ, ε, γ, and μ, respectively.

[0188] A "human antibody" is an antibody having an amino acid sequence corresponding to the amino acid sequence of an antibody produced by a human or human cell, or derived from an antibody of non-human origin using a full repertoire of human antibodies or other human antibody coding sequences. This definition of a human antibody specifically excludes humanized antibodies comprising non-human antigen binding residues. Human antibodies can be produced using various techniques known in the art, including phage display libraries. Hoogenboom and Winter. J. Mol. Biol. 227: 381, 1991; Marks et al. J. Mol. Biol. 222: 581, 1991. Methods for preparing human monoclonal antibodies can also be described in Cole et al., Monoclonal Antibodies and Cancer Therapy, Alan R. Liss, p. 77 (1985); Boerner et al., J. Immunol., 147 (1): 86-95, 1991. See also van Dijk and van de Winkel. Curr. Opin. Pharmacol. 5:368-74, 2001. Human antibodies can be prepared by administering an antigen to a transgenic animal that has been modified to produce such antibodies in response to antigenic challenge but whose endogenous loci have been disabled, e.g., immunizing a xenogeneic mouse (see, e.g., regarding XENOMOUSE TM Nos. 6,075,181 and 6,150,584 of the Human B Cell Hybridoma Technology). See also, e.g., Li et al. Proc. Natl. Acad. Sci. USA. 103:3557-3562, 2006 for human antibodies generated via human B cell hybridoma technology.

[0189] A "human consensus framework" is a framework that represents the most commonly occurring amino acid residues in a selection of human immunoglobulin VL or VH framework sequences. In general, the selection of human immunoglobulin VL or VH sequences is from a subgroup of variable domain sequences. In general, the subgroup of sequences is a subgroup as described in Kabat et al. Sequences of Proteins of Immunological Interest, Fifth Edition, NIH Publication 91-3242, Bethesda MD (1991), Volumes 1-3. In one aspect, for VL, the subgroup is subgroup κI as in Kabat et al., supra. In one aspect, for VH, the subgroup is subgroup III as in Kabat et al., supra.

[0190] "Humanized" antibody refers to such chimeric antibody, which includes amino acid residues from non-human HVR and amino acid residues from human FR. In some aspects, humanized antibody will substantially include all at least one, and usually two variable domains, wherein all or substantially all HVR (e.g., CDR) correspond to the HVR of non-human antibodies, and all or substantially all FRs correspond to the FRs of human antibodies. In some aspects in which all or substantially all FRs of humanized antibodies correspond to the FRs of human antibodies, any FR of humanized antibodies may contain one or more amino acid residues from non-human FRs (e.g., one or more vernier position residues of FR). Humanized antibodies may optionally include at least a portion of an antibody constant region derived from human antibodies. "Humanized form" antibodies, such as non-human antibodies, refer to antibodies that have undergone humanization.

[0191] The term "variable region" or "variable domain" refers to the domain of an antibody heavy chain or light chain that participates in the binding of an antibody to an antigen. The variable domains of the heavy and light chains of natural antibodies (VH and VL, respectively) generally have similar structures, wherein each domain comprises four conserved framework regions (FRs) and three hypervariable regions (HVRs). (See, e.g., Kindt et al. Kuby Immunology, 6th edition, WH Freeman and Co., p. 91 (2007).) A single VH or VL domain may be sufficient to confer antigen binding specificity. In addition, antibodies that bind to a specific antigen can be isolated using VH or VL domains from antibodies that bind to the antigen to screen libraries of complementary VL or VH domains, respectively. See, e.g., Portolano et al. J. Immunol. 150: 880-887, 1993; Clarkson et al. Nature 352: 624-628, 1991.

[0192] As used herein, the term "hypervariable region" or "HVR" refers to each region of an antibody variable domain that is hypervariable in sequence ("complementarity determining region" or "CDR"). Typically, an antibody comprises six CDRs; three in VH (CDR-H1, CDR-H2, CDR-H3), and three in VL (CDR-L1, CDR-L2, CDR-L3). Exemplary CDRs herein include:

[0193] (a) CDRs present at amino acid residues 26-32 (L1), 50-52 (L2), 91-96 (L3), 26-32 (H1), 53-55 (H2), and 96-101 (H3) (Chothia and Lesk, J. Mol. Biol. 196:901-917, 1987);

[0194] (b) the CDRs present at amino acid residues 24-34 (L1), 50-56 (L2), 89-97 (L3), 31-35b (H1), 50-65 (H2), and 95-102 (H3) (Kabat et al., Sequences of Proteins of Immunological Interest, 5th ed., Public Health Service, National Institutes of Health, Bethesda, MD (1991)); and

[0195] (c) Antigenic contact points present at amino acid residues 27c-36 (L1), 46-55 (L2), 89-96 (L3), 30-35b (H1), 47-58 (H2), and 93-101 (H3) (MacCallum et al. J. Mol. Biol. 262:732-745, 1996).

[0196] Unless otherwise indicated, HVR residues and other residues in the variable domain (eg, FR residues) are numbered herein according to Kabat et al., supra.

[0197] "Single-chain Fv", also abbreviated as "sFv" or "scFv", is an antibody fragment comprising VH and VL antibody domains linked into a single polypeptide chain. Preferably, the scFv polypeptide further comprises a polypeptide linker between the VH and VL domains, allowing the scFv to form a desired antigen binding structure. For a review of scFv, see Pluckthun, The Pharmacology of Monoclonal Antibodies, Vol. 113, Rosenburg and Moore, eds., Springer-Verlag, New York, pp. 269-315 (1994); Malmborg et al., J. Immunol. Methods 183:7-13, 1995.

[0198] "Targeting domain" means a portion of a compound or molecule that specifically binds to a target epitope, antigen, ligand, or receptor. Targeting domains include, but are not limited to, antibodies (e.g., monoclonal antibodies, polyclonal antibodies, recombinant antibodies, humanized antibodies, and chimeric antibodies), antibody fragments or portions thereof (e.g., bi-Fab fragments, Fab fragments, Fab' 2, scFab, scFv antibodies, SMIPs, single domain antibodies, diabodies, minibodies, scFv-Fc, affibodies, nanobodies, and VH and / or VL domains of antibodies), receptors, ligands, aptamers, peptide targeting domains (e.g., cysteine ​​knot proteins (CKPs)) and other molecules with identified binding partners. The targeting domain can target, block, agonize or antagonize the antigen bound to it.

[0199] The term "monoclonal antibody" as used herein refers to an antibody obtained from a substantially homogeneous antibody population, that is, except for possible variant antibodies (e.g., containing naturally occurring mutations or produced during the production of monoclonal antibody preparations, such variants are usually present in small amounts), the individual antibodies comprising the population have identity and / or bind to the same epitope. Contrary to the polyclonal antibody preparations that generally include different antibodies for different determinants (epitopes), each monoclonal antibody in the monoclonal antibody preparation is directed to a single determinant on the antigen. Therefore, the modifier "monoclonal" represents that the feature of the antibody is obtained from a substantially homogeneous antibody population, and should not be interpreted as requiring antibody to be produced by any ad hoc method. For example, the monoclonal antibody to be used according to the present invention can be prepared by a variety of techniques, including but not limited to hybridoma methods, recombinant DNA methods, phage display methods, and methods utilizing transgenic animals containing all or part of human immunoglobulin loci, such methods and other exemplary methods for preparing monoclonal antibodies are described herein.

[0200] The term "multispecific antibody" is used in the broadest sense and specifically encompasses antibodies with multi-epitope specificity. In one aspect, a multispecific antibody binds to two different targets (e.g., a bispecific antibody). Such multispecific antibodies include, but are not limited to, antibodies comprising a heavy chain variable domain (VH) and a light chain variable domain (VL), wherein the VH / VL unit has multi-epitope specificity; antibodies having two or more VL and VH domains, wherein each VH / VL unit binds to a different epitope; antibodies having two or more single variable domains, wherein each single variable domain binds to a different epitope; full-length antibodies; antibody fragments such as Fab, Fv, dsFv, scFv, diabodies, bispecific diabodies and triabodies, covalently or non-covalently linked antibody fragments. "Multi-epitope specificity" refers to the ability to specifically bind to two or more different epitopes on the same or different targets. "Monospecificity" refers to the ability to bind only one antigen. In one aspect, a monospecific bi-epitope antibody binds to two different epitopes on the same target / antigen. In one aspect, a monospecific multi-epitope antibody binds to multiple different epitopes of the same target / antigen. According to one aspect, a multispecific antibody is an IgG antibody that binds to each epitope with an affinity of 5 μM to 0.001 pM, 3 μM to 0.001 pM, 1 μM to 0.001 pM, 0.5 μM to 0.001 pM, or 0.1 μM to 0.001 pM.

[0201] "Naked antibody" refers to an antibody that is not conjugated to a heterologous moiety (eg, a cytotoxic moiety) or a radiolabel. Naked antibodies can be present in pharmaceutical formulations.

[0202] "Natural antibodies" refer to naturally occurring immunoglobulin molecules with different structures. For example, natural IgG antibodies are heterotetrameric glycoproteins of about 150,000 daltons, consisting of two identical light chains and two identical heavy chains bonded by disulfide bonds. From the N-terminus to the C-terminus, each heavy chain has a variable region (VH), also known as a variable heavy chain domain or a heavy chain variable domain, followed by three constant domains (CH1, CH2, and CH3). Similarly, from the N-terminus to the C-terminus, each light chain has a variable region (VL), also known as a variable light chain domain or a light chain variable domain, followed by a constant light chain (CL) domain. The light chain of an antibody can be classified into one of two types based on the amino acid sequence of its constant domain, which are called kappa (κ) and lambda (λ).

[0203] As used herein, the term "immunoadhesin" refers to a molecule that combines the binding specificity of a heterologous protein ("adhesin") with the effector function of an immunoglobulin constant domain. Structurally, an immunoadhesin comprises a fusion of an amino acid sequence with a desired binding specificity and an immunoglobulin constant domain sequence (e.g., CH2 and / or CH3 sequence of IgG), which is not an antigen recognition and binding site of an antibody (i.e., "heterologous" compared to the constant region of an antibody). Adhesin and immunoglobulin constant domains may optionally be separated by an amino acid spacer sequence. Exemplary adhesin sequences include continuous amino acid sequences that include a portion of a receptor or ligand that is bound to a target protein. Adhesin sequences may also be sequences that bind to a target protein, but are not receptor or ligand sequences (e.g., adhesin sequences in peptibodies). Such polypeptide sequences may be selected or identified by various methods, including phage display technology and high-throughput sorting methods. The immunoglobulin constant domain sequences in the immunoadhesins may be obtained from any immunoglobulin, such as IgG1, IgG2, IgG3 or IgG4 subtypes, IgA (including IgA1 and IgA2), IgE, IgD or IgM.

[0204] "Chemotherapeutic agents" include chemical compounds that can be used to treat cancer. Examples of chemotherapeutic agents include: erlotinib ( Genentech / OSI Pharm.); Bortezomib ( Millennium Pharm.); disulfiram; epigallocatechin gallate; salinosporamide A; carfilzomib; 17-AAG (geldanamycin); radicicol; lactate dehydrogenase (LDH-A); fulvestrant ( AstraZeneca); sunitib ( Pfizer / Sugen; Letrozole ( Novartis; Imatinib mesylate ( Novartis);finasunate( Novartis; Oxaliplatin ( Sanofi); 5-FU (5-fluorouracil); folinic acid; rapamycin (Sirolimus, Wyeth; Lapatinib ( GSK572016, Glaxo Smith Kline); Lonafamib (SCH 66336); Sorafenib ( Bayer Labs); Gefitinib ( AstraZeneca); AG1478; alkylating agents such as thiotepa and Cyclophosphamide; alkyl sulfonates such as busulfan, improsulfan and piposulfan; aziridines such as benzodepa, carboquinone, metodepa and uredepa; ethyleneimines and methylmelamines including altretamine, trothamide, triethylenephosphoramide, triethylenethiophosphoramide and trihydroxymethylmelamine; annonaceous lactones (especially bratacin and bratacinone); camptothecins (including topotecan and irinotecan); bryostatin; carlistatin; CC-1065 (including its synthetic analogs adolesine, carzeresine and biszeresine); candidiasis (especially candidiasis 1 and candidiasis 8); adrenocortical steroids (including prednisone and prednisolone); cyproterone acetate; 5α-reductase inhibitors including finasteride and dutasteride ); vorinostat, romidepsin, panobinostat, valproic acid, moxistat, dolastat; aldesleukin, talcum duocarcin (including synthetic analogs, KW-2189 and CB1-TM1); acanthopanacine; stoloniferin; spongestatin; nitrogen mustards, such as chlorambucil, naphthyl mustard, clofosamide, estramustine, ifosfamide, dichloromethyl diethylamine, methoxychlor, mycoplasma, new nitrogen mustard, phenylephrine, prednimustine, trofosfamide, uracil mustard; nitrosoureas, such as carmustine, chlorozotocin, fotemustine, lomustine, nimustine and ranimustine; antibiotics, such as enediyne antibiotics (e.g., calicheamicin, especially calicheamicin gamma 1I and calicheamicin omega 1I (Angewandte), Chem. Intl. Ed. Engl. 1994 33:183-186); danemycins, including danemycin A; bisphosphonates, such as clodronate; esmicin; and neostatin chromophores and related chromophores of enediyne antibiotics; aclarubicin, dactinomycin, anthramycin, azoserine, bleomycin, actinomycin, carrubicin, carmomycin, chromomycin, dactinomycin, daunomycin, detoxibacin, 6-azido-5-oxo-L-norleucine, (doxorubicin), morpholino-doxorubicin, cyanomorpholino-doxorubicin, 2-pyrroline-doxorubicin and deoxydoxorubicin, epirubicin, isorubicin, idarubicin, marseromycin; mitomycins such as mitomycin C, mycophenolic acid, nogamycin, olive mycin, peplomycin, methyl mitomycin, puromycin, triferric doxorubicin, rhodorubicin, streptozotocin, streptozotocin, tuberculocin, ubenimex, netastatin, zorubicin; antimetabolites such as methotrexate and 5-fluorouracil (5-FU); folic acid analogs such as methotrexate, methotrexate, pterin, trimetapterin; purine analogs such as fludarabine, 6-mercaptopurine, thiamethoxam, thioguanine; pyrimidine analogs such as ancitabine, azacitidine, 6-azauracil, camothuron, Cytarabine, dideoxyuridine, deoxyfluridine, enocitabine, fluorouracil; androgens such as calosterone, drostanolone propionate, cyclothiocarb, mestanolidine, testolactone; antiadreners such as aminoglutamic acid, mitotane, trilostane; folic acid supplements such as folic acid; aceglucuronosyl lactone; aldosides; aminolevulinic acid; eniluracil; amsacrine; betribucil; bisantrene; idarucizumab Troxa; defosfamide; colcemid; imidoquinone; elonicetate; elliptonium acetate; epothilone; ethoxydimidine; gallium nitrate; hydroxyurea; lentinan; lonidamine; maytansine alkaloids, such as maytansine and ansamitocin; mitoguanidine; mitoxantrone; mopidarol; diamine nitracrine; pentostatin; methamine nitrogen mustard; pirarubicin; losoxantrone; podophyllic acid; 2-ethylhydrazine; methylbenzylhydrazine; polysaccharide complex (JHS Natural Products, Eugene, Oreg.); razoxane; rhizoxin; schizophyllan; spirogermanamine; tenuisporic acid; triazoquinone; 2,2',2"-trichlorotriethylamine; trichothecenes (especially T-2 toxin, vilakulin A, mycloracin A and serpentin); urethane; vindesine; dacarbazine; mannitol mustard; dibromomannitol; dibromodulanol; pipobroman; garcitocin; arabinoside ("Ara-C"); cyclophosphamide; thiotepa; taxanes, such as TAXOL (paclitaxel; Bristol-Myers Squibb Oncology, Princeton, NJ), (without hydrogenated castor oil), albumin-engineered nanoparticle formulation of paclitaxel (American Pharmaceutical Partners, Schaumberg, Ill.), and (docetaxel, docetaxel; sanofi-aventis); chlorambucil; (gemcitabine); 6-thioguanine; mercaptopurine; methotrexate; platinum analogs such as cisplatin and carboplatin; vinblastine; etoposide (VP-16); ifosfamide; mitoxantrone; vincristine; (Vinorelbine); Novantone; Teniposide; Edatrexed; Daunorubicin; Aminopterin; Capecitabine Ibandronate; CPT-11; topoisomerase inhibitor RFS2000; difluoromethylornithine (DMFO); retinoids, such as retinoic acid; and pharmaceutically acceptable salts, acids and derivatives of any of the above.

[0205] Chemotherapeutic agents also include: (i) antihormonal agents that act to modulate or inhibit the effects of hormones on tumors, such as antiestrogens and selective estrogen receptor modulators (SERMs), including tamoxifen (including Tamoxifen citrate), raloxifene, droloxifene, iodoxyfene, 4-hydroxytamoxifen, trooxifene, raloxifene hydrochloride, LY117018, onapristone and (tomiphene citrate); (ii) aromatase inhibitors that inhibit aromatase, an enzyme that regulates estrogen production by the adrenal glands, such as 4(5)-imidazole, aminoglutethimide, (Megestrol acetate), (exemestane; Pfizer), formestane, fadrozole, (Vorozole), (letrozole; Novartis) and (anastrozole; AstraZeneca); (iii) antiandrogens, such as flutamide, nilutamide, bicalutamide, leuprolide, and goserelin; buserelin, triptorelin, medroxyprogesterone acetate, diethylstilbestrol, premarin, fluoxymesterone, all trans-retinoic acids, retinamide, and troxacitabine (a 1,3-dioxolane nucleoside cytosine analog); (iv) protein kinase inhibitors; (v) lipid kinase inhibitors; (vi) antisense oligonucleotides, particularly those that inhibit the expression of genes in signal transduction pathways involved in abnormal cell proliferation, such as PKC-α, Ralf, and H-Ras; (vii) ribozymes, such as inhibitors of VEGF expression (e.g. ) and HER2 expression inhibitors; (viii) vaccines, such as gene therapy vaccines, such as and rIL-2; topoisomerase 1 inhibitors, e.g. and (ix) any of the pharmaceutically acceptable salts, acids and derivatives of the foregoing.

[0206] Chemotherapeutic agents also include antibodies such as alemtuzumab (Campath), bevacizumab ( Genentech; Cetuximab ( Imclone; Panitumumab ( Amgen), rituximab ( Genentech / Biogen Idec), Pertuzumab ( 2C4, Genentech), trastuzumab ( Genentech), tositumomab (Bexxar, Corixia) and antibody-drug conjugates, gemtuzumab ozogamicin ( Wyeth). Other humanized monoclonal antibodies with therapeutic potential for combination with the compounds of the present invention include: apolizumab, aselizumab, alizumab, barbiturumab, bivatuzumab mertansine, cantuzumab mertansine, cedelizumab, certolizumab pegol, cidfusituzumab, cidtuzumab, daclizumab, eculizumab, efalizumab, epratuzumab, erlizumab, felvizumab, fontolizumab, gemtuzumab ozogamicin, inotuzumab ozogamicin), ipilimumab, labetuzumab, lintuzumab, matuzumab, mepolizumab, motavizumab, motovizumab, natalizumab, nimotuzumab, nolovizumab, numavizumab, ocrelizumab, omalizumab, palivizumab, pascolizumab, pecfusituzumab , pectuzumab, pexelizumab, ralivizumab, ranibizumab, reslivizumab, reslizumab, resyvizumab, rovelizumab, ruplizumab, sirolimusumab, cilizumab, sontuzumab, tacatuzumab tetraxetan), tadocizumab, tadocizumab, tefibazumab, tocilizumab, toralizumab, tucotuzumab celmoleukin, tucusituzumab, umavizumab, uzumab, ustekinumab, visilizumab, and anti-interleukin-12 (ABT-874 / J695,Wyeth Research and Abbott Laboratories) (Anti-IL-12 is a recombinant, human-specific sequence, full-length IgG1λ antibody genetically modified to recognize the IL-12p40 protein).

[0207] Chemotherapeutic agents also include "EGFR inhibitors", which refer to compounds that bind to or directly interact with EGFR and prevent or reduce its signaling activity, and are alternatively referred to as "EGFR antagonists". Examples of such agents include antibodies and small molecules that bind to EGFR. Examples of antibodies that bind to EGFR include MAb 579 (ATCC CRL HB 8506), MAb 455 (ATCC CRL HB8507), MAb 225 (ATCC CRL 8508), MAb 528 (ATCC CRL 8509) (see, U.S. Pat. No. 4,943,533, Mendelsohn et al.) and variants thereof, such as chimeric 225 (C225 or cetuximab; ) and remodeled human 225 (H225) (see, WO 96 / 40210, Imclone Systems Inc.); IMC-11F8, a fully human antibody targeting EGFR (Imclone); antibodies that bind to type II mutant EGFR (U.S. Pat. No. 5,212,290); humanized and chimeric antibodies that bind to EGFR as described in U.S. Pat. No. 5,891,996; and human antibodies that bind to EGFR, such as ABX-EGF or panitumumab (see WO 98 / 50433, Abgenix / Amgen); EMD55900 (Stragliotto et al. Eur. J. Cancer 32A:636-640 (1996)); EMD7200 (matuzumab), a humanized EGFR antibody against EGFR that competes with EGF and TGF-α for binding to EGFR (EMD / Merck); human EGFR antibody, HuMax-EGFR (GenMab); fully human antibodies, designated E1.1, E2.4, E2.5, E6.2, E6.4, E2.11, E6.3, and E7.6.3, and described in US 6,235,883; MDX-447 (Medarex Inc); and mAb 806 or humanized mAb 806 (Johns et al., J. Biol. Chem. 279(29):30375-30384 (2004)). Anti-EGFR antibodies can be conjugated to cytotoxic agents to generate immunoconjugates (see, e.g., EP 659,439 A2, Merck Patent GmbH). EGFR antagonists include small molecules such as U.S. Pat. Nos. 5,616,582, 5,457,105, 5,475,001, 5,654,307, 5,679,683, 6,084,095, 6,265,410, 6,455,534, 6,521,620, 6,596,726, 6,713,484, 5,770,599, 6,140,332, 5, 866,572, 6,399,602, 6,344,459, 6,602,863, 6,391,874, 6,344,455, 5,760,041, 6,002,008 and 5,747,498, and the following PCT publications: WO98 / 14451, WO98 / 50038, WO99 / 09016 and WO99 / 24037. Specific small molecule EGFR antagonists include OSI-774 (CP-358774, erlotinib, Genentech / OSI Pharmaceuticals); PD 183805 (CI 1033, 2-acrylamide, N-[4-[(3-chloro-4-fluorophenyl)amino]-7-[3-(4-morpholinyl)propoxy]-6-quinazolinyl]-, dihydrochloride, Pfizer); ZD1839, gefitinib 4-(3'-chloro-4'-fluoroanilino)-7-methoxy-6-(3-morpholinopropoxy)quinazoline, AstraZeneca); ZM 105180 (6-amino-4-(3-methylphenyl-amino)-quinazoline, Zeneca); BIBX-1382 (N8-(3-chloro-4-fluoro-phenyl)-N2-(1-methyl-piperidin-4-yl)-pyrimido[5,4-d]pyrimidine-2,8-diamine, Boehringer Ingelheim Ingelheim); PKI-166 ((R)-4-[4-[(1-phenylethyl)amino]-1H-pyrrolo[2,3-d]pyrimidin-6-yl]-phenol); (R)-6-(4-hydroxyphenyl)-4-[(1-phenylethyl)amino]-7H-pyrrolo[2,3-d]pyrimidine); CL-387785 (N-[4-[(3-bromophenyl)amino]-6-quinazolinyl]-2-butynamide); EKB-569 (N-[4-[(3-chloro-4-fluorophenyl)amino]-3-cyano-7-ethoxy-6-quinolinyl]-4-(dimethylamino)-2-butenamide) (Wyeth); AG1478 (Pfizer); AG1571 (SU 5271; Pfizer); dual EGFR / HER2 tyrosine kinase inhibitors such as lapatinib ( GSK572016 or N-[3-chloro-4-[(3-fluorophenyl)methoxy]phenyl]-6[5[[[(2-methylsulfonyl)ethyl]amino]methyl]-2-furyl]-4-quinazolinamine).

[0208] Chemotherapeutic agents also include "tyrosine kinase inhibitors", including the EGFR targeted drugs described in the previous paragraph; small molecule HER2 tyrosine kinase inhibitors, such as TAK165 available from Takeda Pharmaceuticals; CP-724,714, an oral selective inhibitor of ErbB2 receptor tyrosine kinase (Pfizer and OSI); dual HER inhibitors, such as EKB-569 (available from Wyeth), which preferentially binds to EGFR but simultaneously inhibits cells overexpressing HER2 and EGFR; lapatinib (GSK572016; available from GlaxoSmithKline), an oral HER2 and EGFR tyrosine kinase inhibitor; PKI-166 (available from Novartis); pan-HER inhibitors, such as canertinib (CI-1033; Pharmacia); Raf-1 inhibitors, such as ISIS-5132, an antisense agent that inhibits Raf-1 signaling, available from ISIS Pharmaceuticals; non-HER targeted TK inhibitors, such as imatinib mesylate ( available from GlaxoSmithKline); multitargeted tyrosine kinase inhibitors such as sunitinib ( VEGF receptor tyrosine kinase inhibitors such as vatalanib (PTK787 / ZK222584, available from Novartis / Schering AG); MAPK extracellular regulated kinase I inhibitor CI-1040 (available from Pharmacia); quinazolines such as PD 153035, 4-(3-chloroanilino)quinazoline; pyridopyrimidines; pyrimidopyrimidines; pyrrolopyrimidines such as CGP 59326, CGP60261 and CGP 62706; pyrazolopyrimidines, 4-(phenylamino)-7H-pyrrolo[2,3-d]pyrimidine; curcumin (difluoroformylmethane, 4,5-bis(4-fluoroanilino)phthalimide); tyrosine tyrosine containing a nitrothiophene moiety; PD-0183805 (Warner-Lamber); antisense molecules (e.g., molecules that bind to HER encoding nucleic acids); quinoxalines (U.S. Pat. No. 5,804,396); tyrosine phosphorylation inhibitors (U.S. Pat. No. 5,804,396); ZD6474 (AstraZeneca); PTK-787 (Novartis / Schering AG); pan-HER inhibitors, such as CI-1033 (Pfizer); Affinitac (ISIS 3521; Isis / Lilly); imatinib mesylate PKI 166 (Novartis); GW2016 (GlaxoSmithKline); CI-1033 (Pfizer); EKB-569 (Wyeth); seramatinib (Pfizer); ZD6474 (AstraZeneca); PTK-787 (Novartis / Schering); INC-1C11 (Imclone), rapamycin (sirolimus, ); or any of the following patent publications: U.S. Pat. No. 5,804,396, WO 1999 / 09016 (American Cyanamid), WO 1998 / 43960 (American Cyanamid), WO 1997 / 38983 (Warner Lambert), WO 1999 / 06378 (Warner Lambert), WO 1999 / 06396 (Warner Lambert), WO 1996 / 30347 (Pfizer, Inc), WO 1996 / 33978 (Zeneca), WO 1996 / 3397 (Zeneca), and WO 1996 / 33980 (Zeneca).

[0209] Chemotherapeutic agents also include dexamethasone, interferon, colchicine, metoprine, cyclosporine, amphotericin, metronidazole, alemtuzumab, alitretinoin, allopurinol, amifostine, arsenic trioxide, asparaginase, live BCG, bevacizumab, bexarotene, cladribine, clofarabine, darbepoetin alfa, denileukin, dexrazoxane, epoetin alfa, erlotinib, filgrastim, histrelin acetate, acetate), ibritumomab, interferon alfa-2a, interferon alfa-2b, lenalidomide, levamisole, mesna, methoxsalen, nandrolone, nelarabine, nofetumomab, oprelvekin, palifermin, pamidronate, pegademase, pegaspargase, pegfilgrastim, pemetrexed disodium, plicamycin, porfimer sodium sodium), quinacrine, rasburicase, sargramostim, temozolomide, VM-26, 6-TG, toremifene, tretinoin, ATRA, valrubicin, zoledronate and zoledronic acid and pharmaceutically acceptable salts thereof.

[0210] Chemotherapeutic agents also include hydrocortisone, hydrocortisone acetate, cortisone acetate, thiocortisone pivalate, triamcinolone acetonide, triamcinolone acetonide alcohol, mometasone, amcinonide, budesonide, desonide, fluocinolone acetate, fluocinolone, betamethasone, betamethasone sodium phosphate, dexamethasone, dexamethasone sodium phosphate, fluocortolone, hydrocortisone-17-butyrate, hydrocortisone-17-valerate, aclometasone dipropionate, and phenoxyethanol. dipropionate), betamethasone valerate, betamethasone dipropionate, prednicarbate, clobetasone-17-butyrate, clobetasol-17-propionate, fluocortolone hexanoate, fluocortolone valerate, and flupredniidine acetate; immunoselective anti-inflammatory peptides (ImSAIDs), such as phenylalanine-glutamine-glycine (FEG) and its D-isomer form (feG) (IMULAN Biotherapeutics Ltd. BioTherapeutics, LLC); antirheumatic drugs such as azathioprine, cyclosporine (cyclosporine A), D-penicillamine, gold salts, hydroxychloroquine, leflunomide, minocycline, sulfasalazine; tumor necrosis factor alpha (TNFα) blockers such as etanercept (Enbrel), infliximab (Remicade), adalimumab (Humira), certolizumab pegol (Cimzia), golimumab (Simponi); interleukin 1 (IL-1) blockers such as anakinra (Kineret); T-cell costimulation blockers such as abatacept (Orencia); interleukin 6 (IL-6) blockers such as tocilizumab Interleukin 13 (IL-13) blockers, such as lebrikizumab; interferon alpha (IFN) blockers, such as lonavirin; β7 integrin blockers, such as rhuMAb β7; IgE pathway blockers, such as anti-M1 primers; secreted homotrimeric LTa3 and membrane-bound heterotrimeric LTa1 / β2 blockers, such as anti-lymphotoxin alpha (LTa); radioisotopes (e.g. At 211 ,I 131 ,I 125 , Y 90 、Re 186 、Re 188 、Sm 153 、Bi 212 , P 32 , Pb 212and radioisotopes of Lu); various experimental agents such as thioplatin, PS-341, phenylbutyrate, ET-18-OCH3 or farnesyl transferase inhibitors (L-739749, L-744832); polyphenols such as quercetin, resveratrol, picrophenol, epigallocatechin gallate, theaflavins, flavanols, proanthocyanidins, betulinic acid and its derivatives; autophagy inhibitors such as chloroquine; delta-9-tetrahydrocannabinol (dronabinol, ); β-lapachone; lapaol; colchicine; betulinic acid; acetylcamptothecin, scopolectin, and 9-aminocamptothecin); podophyllotoxin; tegafur Bexarotene Bisphosphonates, such as clodronate (e.g. or ), etidronate NE-58095, Zoledronic Acid / Zoledronate Alendronate Pamidronate Tirodronate Risedronate and epidermal growth factor receptor (EGF-R); vaccines such as Vaccines; Perifosine; COX-2 inhibitors (e.g., celecoxib or etoricoxib); proteosome inhibitors (e.g., PS341); CCI-779; Tipifarnib (R11577); Orafenib, ABT510; Bcl-2 inhibitors such as oblimersen sodium Pixantrone; farnesyl transferase inhibitors such as lonafarnib (SCH 6636, SARASAR TM ); and pharmaceutically acceptable salts, acids or derivatives of any of the above; and combinations of two or more of the above, such as CHOP (an abbreviation for the combination therapy of cyclophosphamide, doxorubicin, vincristine and prednisolone); and FOLFOX (oxaliplatin (ELOXATIN TM ) is an abbreviation for the combination therapy with 5-FU and folinate).

[0211] Chemotherapeutic agents also include nonsteroidal anti-inflammatory drugs with analgesic, antipyretic and anti-inflammatory effects.NSAID includes non-selective inhibitors of cyclooxygenase.Specific examples of NSAID include aspirin, propionic acid derivatives (such as ibuprofen, fenoprofen, ketoprofen, flurbiprofen, oxaprozin and naproxen), acetic acid derivatives (such as indomethacin, sulindac, etodolac, diclofenac), enolic acid derivatives (such as piroxicam, meloxicam, tenoxicam, droxicam and lornoxicam), fenamic acid derivatives (such as mefenamic acid, meclofenamic acid, flufenamic acid, toluenesulfonic acid) and COX-2 inhibitors (such as celecoxib, etoricoxib, lumixib, parecoxib, rofecoxib and valdecoxib). NSAIDs may be useful for relieving symptoms of conditions such as rheumatoid arthritis, osteoarthritis, inflammatory arthritis, ankylosing spondylitis, psoriatic arthritis, Reiter's syndrome, acute gout, dysmenorrhea, metastatic bone pain, headaches and migraines, postoperative pain, mild to moderate pain due to inflammation and tissue damage, fever, intestinal obstruction, and renal colic.

[0212] As used herein, the term "cytotoxic agent" refers to a substance that inhibits or prevents cellular function and / or causes cell death or destruction. Cytotoxic agents include, but are not limited to, radioactive isotopes (e.g., At 211 ,I 131 ,I 125 , Y 90 、Re 186 、Re 188 、Sm 153 、Bi 212 , P 32 , Pb 212 and radioactive isotopes of Lu); chemotherapeutic agents or drugs (e.g., methotrexate, doxorubicin, vinca alkaloids (vincristine, vinblastine, etoposide), doxorubicin, melphalan, mitomycin C, chlorambucil, daunorubicin or other intercalating agents); growth inhibitors; 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 various anti-tumor or anti-cancer drugs disclosed below.

[0213] A "disorder" is any condition that would benefit from treatment, including but not limited to chronic and acute disorders or diseases, including those pathological conditions that predispose the mammal to the disorder. In one aspect, the disorder is cancer, such as multiple myeloma (MM).

[0214] The terms "cell proliferative disorder" and "proliferative disorder" refer to a disorder associated with some degree of abnormal cell proliferation. In one aspect, the cell proliferative disorder is cancer. In one aspect, the cell proliferative disorder is a tumor.

[0215] As used herein, the term "tumor" refers to all neoplastic cell growth and proliferation, whether malignant or benign, and all precancerous and cancerous cells and tissues. The terms "cancer," "cancerous," "cell proliferative disorders," "proliferative disorders," and "tumor" are not mutually exclusive herein.

[0216] The terms "cancer" and "cancerous" refer to or describe a physiological condition in mammals that is generally characterized by uncontrolled cell growth / proliferation. Aspects of cancer include solid tumor cancers and non-solid tumor cancers. Examples of cancer include, but are not limited to, B cell proliferative disorders such as multiple myeloma (MM), which may be relapsed or refractory MM. MM may be, for example, classic MM (e.g., immunoglobulin G (IgG) MM, IgA MM, IgD MM, IgE MM, or IgM MM), light chain MM (LCMM) (e.g., λ light chain MM or κ light chain MM), or non-secretory MM. MM may have one or more cytogenetic features (e.g., high-risk cytogenetic features), for example, t(4;14), t(11;14), t(14;16), and / or del(17p) (as described in Table 1 and the International Myeloma Working Group (IMWG) criteria provided in Sonneveld et al., Blood, 127(24):2955-2962, 2016), and / or 1q21 (as described in Chang et al., Bone Marrow Transplantation, 45:117-121, 2010). Cytogenetic features can be detected, for example, using fluorescent in situ hybridization (FISH).

[0217] Table 1. Cytogenetic characteristics of MM

[0218]

[0219] The term "B cell proliferative disorder" or "B cell malignancy" refers to a disorder associated with some degree of abnormal B cell proliferation, and includes, for example, lymphoma, leukemia, myeloma, and myelodysplastic syndrome. In one embodiment, the B cell proliferative disorder is a lymphoma, such as non-Hodgkin's lymphoma (NHL), including, for example, diffuse large B cell lymphoma (DLBCL) (e.g., relapsed or refractory DLBCL). In another embodiment, the B cell proliferative disorder is a leukemia, such as chronic lymphocytic leukemia (CLL). Other specific examples of cancer include germinal center B cell-like (GCB) diffuse large B cell lymphoma (DLBCL), activated B cell-like (ABC) DLBCL, follicular lymphoma (FL), mantle cell lymphoma (MCL), acute myeloid leukemia (AML), chronic lymphocytic leukemia (CLL), marginal zone lymphoma (MZL), small lymphocytic leukemia (SLL), lymphoplasmacytic lymphoma (LL), Waldenstrom's macroglobulinemia (WM), central nervous system lymphoma (CNSL), Burkitt's lymphoma (BL), precursor B cell lymphocytic leukemia, splenic marginal zone lymphoma, hairy cell leukemia, splenic lymphoma / leukemia (unclassifiable), splenic diffuse red pulp small B cell lymphoma, variant hairy cell leukemia, heavy chain disease (alpha heavy chain disease, gamma heavy chain disease, mu heavy chain disease), plasma cell myeloma, solitary plasmacytoma of bone, extraosseous plasmacytoma, mucosal leukemia, Extranodal marginal zone lymphoma of lymphoid tissue (MALT lymphoma), nodal marginal zone lymphoma, pediatric nodal marginal zone lymphoma, pediatric follicular lymphoma, primary cutaneous follicle center lymphoma, T-cell / histiocyte-rich large B-cell lymphoma, primary DLBCL of the CNS, primary cutaneous DLBCL (leg type), EBV-positive DLBCL of the elderly, DLBCL associated with chronic inflammation, lymphomatoid granuloma, primary mediastinal (thymic) large B-cell lymphoma, intravascular large B-cell lymphoma, ALK-positive large B-cell lymphoma, plasmablastic lymphoma, large B-cell lymphoma due to HHV8-associated multicentric Castleman disease, primary effusion lymphoma: B-cell lymphoma (unclassifiable, with features intermediate between DLBCL and Burkitt's lymphoma), and B-cell lymphoma (unclassifiable, with features intermediate between DLBCL and classical Hodgkin's lymphoma). Another example of cancer includes, but is not limited to, carcinoma, lymphoma, blastoma, sarcoma, and leukemia or lymphoid malignancies, including B-cell lymphoma.More specific examples of such cancers include, but are not limited to: low-grade / follicular NHL; small lymphocytic (SL) NHL; intermediate-grade / follicular NHL; intermediate-grade diffuse NHL; high-grade immunoblastic NHL; high-grade lymphoblastic NHL; high-grade small non-truncated cell NHL; bulky disease NHL; AIDS-related lymphoma; and acute lymphoblastic leukemia (ALL); chronic myeloid leukemia; and post-transplant lymphoproliferative disorder (PTLD). Examples of solid tumors include squamous cell carcinoma (e.g., epithelial squamous cell carcinoma), lung cancer (including small cell lung cancer, non-small cell lung cancer, lung adenocarcinoma, and lung squamous cell carcinoma), peritoneal cancer, hepatocellular carcinoma, gastric cancer (including gastrointestinal cancer and gastrointestinal stromal cancer), pancreatic cancer, glioblastoma, cervical cancer, ovarian cancer, liver cancer, bladder cancer, urinary tract cancer, hepatoma, breast cancer, colon cancer, rectal cancer, colorectal cancer, endometrial or uterine cancer, salivary gland cancer, kidney or renal cancer, prostate cancer, vulvar cancer, thyroid cancer, hepatic carcinoma, anal cancer, penile cancer, melanoma, superficial spreading melanoma, tonsillar malignant melanoma, acral lentiginous melanoma, nodular melanoma, and abnormal vascular proliferation associated with nevus hamartomas, edema (such as associated with brain tumors), Meigs syndrome, brain cancer, and head and neck cancer and related metastases. In certain embodiments, cancers suitable for treatment by the antibodies of the invention include breast cancer, colorectal cancer, rectal cancer, non-small cell lung cancer, glioblastoma, non-Hodgkin lymphoma (NHL), renal cell carcinoma, prostate cancer, liver cancer, pancreatic cancer, soft tissue sarcoma, Kaposi's sarcoma, carcinoid cancer, head and neck cancer, ovarian cancer, and mesothelioma.

[0220] "Effector functions" refer to those biological activities attributable to the Fc region of an antibody, which vary with the antibody isotype. Examples of antibody effector functions include: C1q binding and complement dependent cytotoxicity (CDC); Fc receptor binding; antibody-dependent cell-mediated cytotoxicity (ADCC); phagocytosis; downregulation of cell surface receptors (e.g., B cell receptor); and B cell activation.

[0221] "Complement-dependent cytotoxicity" or "CDC" refers to the lysis of target cells in the presence of complement. Activation of the classical complement pathway is initiated by the binding of the first component of the complement system (C1q) to antibodies (of the appropriate subclass) bound to its cognate antigen. To assess complement activation, a CDC assay may be performed, e.g., as described in Gazzano-Santoro et al. J. Immunol. Methods 202: 163 (1996).

[0222] "Antibody-dependent cell-mediated cytotoxicity" or "ADCC" refers to a form of cytotoxicity in which secreted Ig binds to Fc receptors (FcRs) present on certain cytotoxic cells (e.g., natural killer (NK) cells, neutrophils, and macrophages), allowing these cytotoxic effector cells to specifically bind to target cells bearing antigens and subsequently kill the target cells with cytotoxic agents. Antibodies "arm" cytotoxic cells and are required for such killing. NK cells, the main cells that mediate ADCC, express only FcγRIII, while monocytes express FcγRI, FcγRII, and FcγRIII. FcR expression on hematopoietic cells is summarized in Table 3 of Ravetch and Kinet.Annu.Rev.Immunol.9:457-92, 1991, page 464. To assess the ADCC activity of a target molecule, an in vitro ADCC assay, such as that described in U.S. Pat. No. 5,500,362 or 5,821,337, may be performed. Useful effector cells for such assays include peripheral blood mononuclear cells (PBMC) and natural killer (NK) cells. Alternatively or additionally, the ADCC activity of the target molecule can be assessed in vivo, for example, in an animal model (such as that disclosed in Clynes et al. Proc. Natl. Acad. Sci. USA. 95: 652-656, 1998).

[0223] As used herein, "complex" or "complexed" refers to the association of two or more molecules that interact with each other through bonds and / or forces (e.g., van der Waals, hydrophobic, hydrophilic) other than peptide bonds. In one aspect, the complex is a heteromultimer. It should be understood that the term "protein complex" or "polypeptide complex" as used herein includes complexes of non-protein entities (e.g., including but not limited to chemical molecules such as toxins or detection agents) conjugated to proteins in the protein complex.

[0224] As used herein, "delaying progression" of a condition or disease means slowing, hindering, slowing, delaying, stabilizing, and / or postponing the development of a disease or condition (e.g., a cell proliferative disorder, e.g., cancer). Such delays may be of varying lengths of time, depending on the medical history and / or the individual to be treated. It will be apparent to one skilled in the art that a substantial or significant delay may actually encompass prevention, in that the individual will not develop the disease. For example, the development of an advanced cancer, such as metastasis, may be delayed.

[0225] An "effective amount" of a compound (e.g., an anti-FcRH5 / anti-CD3 T cell-dependent bispecific antibody (TDB) of the invention) or a composition thereof (e.g., a pharmaceutical composition) is at least the minimum amount required to achieve the desired therapeutic or preventive result, such as a measurable improvement or prevention of a particular disorder (e.g., a cell proliferative disorder, such as cancer). The effective amount herein may vary according to factors such as the disease state, age, sex, and weight of the patient, and the ability of the antibody to elicit the desired response in the individual. An effective amount is also an amount in which any toxic or deleterious effects of the treatment are outweighed by the beneficial effects of the treatment. For preventive use, beneficial or expected results include, for example, elimination or reduction of risk, lessening of severity, or delay of disease onset, including biochemical, histological, and / or behavioral symptoms of the disease, its complications, and intermediate pathological phenotypes that occur during the course of disease progression. For therapeutic use, beneficial or expected results include clinical results, such as reduction of one or more symptoms caused by the disease, improvement of the quality of life of the patient, reduction of the dose of other drugs required to treat the disease, enhancement of the effects of other drugs (such as by targeting, slowing disease progression, and / or prolonging survival). In the case of cancer or tumors, an effective amount of a drug may reduce the number of cancer cells; reduce tumor size; inhibit (i.e., slow down or expect to stop to some extent) cancer cell infiltration into surrounding organs; inhibit (i.e., slow down and expect to stop to some extent) tumor metastasis; inhibit the growth of tumors to some extent; and / or alleviate one or more symptoms associated with the condition to some extent. An effective amount may be administered in one or more administrations. For the purposes of the present invention, an effective amount of a drug, compound, or pharmaceutical composition is an amount sufficient to prevent or treat directly or indirectly. As understood in a clinical context, an effective amount of a drug, compound, or pharmaceutical composition may or may not be achieved in combination with another drug, compound, or pharmaceutical composition. Therefore, an "effective amount" may be considered in the context of administering one or more therapeutic agents, and if the desired result can be obtained or achieved in combination with one or more other agents, an effective amount of a single agent may be considered.

[0226] As used herein, "overall survival" or "OS" refers to the percentage of individuals in a group of individuals who are likely to survive after a specific period of time.

[0227] As used herein, "objective response rate" (ORR) refers to the sum of stringent complete response (sCR), complete response (CR), very good partial response (VGPR), and partial response (PR) rates determined using the International Myeloma Working Group response criteria (Table 4).

[0228] The term "epitope" refers to a specific site on an antigen molecule to which an antibody binds. In some aspects, the specific site on an antigen molecule to which an antibody binds is determined by hydroxyl radical footprinting. In some aspects, the specific site on an antigen molecule to which an antibody binds is determined by crystallography.

[0229] When used in this article, "growth inhibitor" refers to a compound or composition that inhibits cell growth in vitro or in vivo. In one aspect, a growth inhibitor is a growth inhibitory antibody that prevents or reduces the proliferation of cells expressing the antigen to which the antibody binds. In another aspect, a growth inhibitor can be an inhibitor that significantly reduces the percentage of cells in the S phase. Aspects of growth inhibitors include agents that block cell cycle progression (in places other than the S phase), such as agents that induce G1 arrest and M phase arrest. Classical M phase blockers include periwinkle (vincristine and vinblastine), taxanes, and topoisomerase II inhibitors (such as doxorubicin, epirubicin, daunorubicin, etoposide, and bleomycin). Those agents that block G1 also overflow into the S phase arrest, such as DNA alkylating agents, such as tamoxifen, prednisone, dacarbazine, nitrogen mustard, cisplatin, methotrexate, 5-fluorouracil, and ara-C. Further information can be found in Chapter 1 by Murakami et al., The Molecular Basis of Cancer, ed., Mendelsohn and Israel, entitled "Cell cycle regulation, oncogenes, and antineoplastic drugs" (WB Saunders, Philadelphia, 1995), e.g., page 13. Taxanes (paclitaxel and docetaxel) are both anticancer drugs derived from yew. Docetaxel ( Rhone-Poulenc Rorer) is derived from European yew and is a semisynthetic analog of paclitaxel ( Bristol-Myers Squibb). Paclitaxel and docetaxel promote microtubule assembly of tubulin dimers and stabilize microtubules by preventing depolymerization, thereby inhibiting cell mitosis.

[0230] An "immunoconjugate" is an antibody conjugated to one or more heterologous molecules, including but not limited to a cytotoxic agent.

[0231] The term "immunomodulator" refers to a class of molecules that alter the immune system response or immune system function. Immunomodulators include, but are not limited to, PD-1 axis binding antagonists, thalidomide (α-N-phthalimide-glutarimide) and its analogs, (Apremilast), (lenalidomide) and (Pomalidomide) and its pharmaceutically acceptable salts or acids.

[0232] A "subject" or "individual" is a mammal. Mammals include, but are not limited to, domesticated animals (e.g., cattle, sheep, cats, dogs, and horses), primates (e.g., humans and non-human primates such as monkeys), rabbits, and rodents (e.g., mice and rats). In certain aspects, the subject or individual is a human.

[0233] An "isolated" protein or peptide is one that has been separated from a component of its natural environment. In some aspects, the protein or peptide is purified to a purity greater than 95% or 99%, as determined by, for example, electrophoresis (e.g., SDS-PAGE, isoelectric focusing (IEF), capillary electrophoresis) or chromatography (e.g., ion exchange or reversed phase HPLC).

[0234] An "isolated" nucleic acid refers to a nucleic acid molecule that has been separated from a component of its natural environment. An isolated nucleic acid includes a nucleic acid molecule contained in cells that ordinarily contain the nucleic acid molecule, but the nucleic acid molecule is present extrachromosomally or at a chromosomal location that is different from its natural chromosomal location.

[0235] The term "PD-1 axis binding antagonist" refers to a molecule that inhibits the interaction of a PD-1 axis binding partner with one or more of its binding partners to eliminate T cell dysfunction caused by signal transduction on the PD-1 signaling axis, resulting in restoration or enhancement of T cell function (e.g., proliferation, cytokine production, and / or target cell killing). As used herein, PD-1 axis binding antagonists include PD-L1 binding antagonists, PD-1 binding antagonists, and PD-L2 binding antagonists. In some cases, PD-1 axis binding antagonists include PD-L1 binding antagonists or PD-1 binding antagonists. In a preferred aspect, the PD-1 axis binding antagonist is a PD-L1 binding antagonist.

[0236] The term "PD-L1 binding antagonist" refers to a molecule that reduces, blocks, inhibits, eliminates or interferes with the signal transduction generated by the interaction of PD-L1 with one or more of its binding partners (such as PD-1 and / or B7-1). In some cases, the PD-L1 binding antagonist is a molecule that inhibits the binding of PD-L1 to its binding partner. In a specific aspect, the PD-L1 binding antagonist inhibits the binding of PD-L1 to PD-1 and / or B7-1. In some cases, the PD-L1 binding antagonist includes anti-PD-L1 antibodies, antigen-binding fragments thereof, immunoadhesins, fusion proteins, oligopeptides and other molecules that reduce, block, inhibit, eliminate or interfere with the signal transduction generated by the interaction of PD-L1 with one or more of its binding partners (such as PD-1 and / or B7-1). In one instance, the PD-L1 binding antagonist reduces the negative co-stimulatory signal mediated by signaling through PD-L1 mediated by or through cell surface proteins expressed on T lymphocytes, thereby rendering the dysfunctional T cells less dysfunctional (e.g., improving the response of effectors to antigen recognition). In some instances, the PD-L1 binding antagonist binds to PD-L1. In some instances, the PD-L1 binding antagonist is an anti-PD-L1 antibody (e.g., an anti-PD-L1 antagonist antibody). Exemplary anti-PD-L1 antagonist antibodies include atezolizumab, MDX-1105, MEDI4736 (durvalumab), MSB0010718C (avelumab), SHR-1316, CS1001, envafolimab, TQB2450, ZKAB001, LP-002, CX-072, IMC-001 , KL-A167, APL-502, cosibelimab, lodapolimab, FAZ053, TG-1501, BGB-A333, BCD-135, AK-106, LDP, GR1405, HLX20, MSB2311, RC98, PDL-GEX, KD036, KY1003, YBL-007, and HS-636. In some aspects, the anti-PD-L1 antibody is atezolizumab, MDX-1105, MEDI4736 (durvalumab), or MSB0010718C (avetumab). In a specific aspect, the PD-L1 binding antagonist is MDX-1105. In another specific aspect, the PD-L1 binding antagonist is MEDI4736 (durvalumab). In another specific aspect, the PD-L1 binding antagonist is MSB0010718C (avelumab).In other aspects, the PD-L1 binding antagonist can be a small molecule, for example, GS-4224, INCB086550, MAX-10181, INCB090244, CA-170 or ABSK041, which can be administered orally in some cases. Other exemplary PD-L1 binding antagonists include AVA-004, MT-6035, VXM10, LYN192, GB7003 and JS-003. In a preferred aspect, the PD-L1 binding antagonist is atezolizumab.

[0237] For the purpose of this article, "atezumab" is an Fc-engineered, humanized, non-glycosylated IgG1κ immunoglobulin that binds PD-L1. Atezolizumab contains a single amino acid substitution (asparagine to alanine) (N297A) at position 297 on the heavy chain, using the EU numbering of Fc region amino acid residues, which results in a non-glycosylated antibody with minimal binding to Fc receptors. Atezolizumab is also described in WHO Drug Information (International Nonproprietary Names of Drug Substances (Proposed INN)) List 112, Vol. 28, No. 4, 2014, p. 488.

[0238] The term "PD-1 binding antagonist" refers to a molecule that reduces, blocks, inhibits, eliminates or interferes with the signal transduction generated by the interaction of PD-1 with one or more of its binding partners (such as PD-L1 and / or PD-L2). PD-1 (programmed death 1) is also referred to as "programmed cell death 1", "PDCD1", "CD279" and "SLEB2" in the art. Exemplary human PD-1 is shown in UniProtKB / Swiss-Prot accession number Q15116. In some cases, a PD-1 binding antagonist is a molecule that inhibits the binding of PD-1 to one or more of its binding partners. In a specific aspect, a PD-1 binding antagonist inhibits the binding of PD-1 to PD-L1 and / or PD-L2. For example, PD-1 binding antagonists include anti-PD-1 antibodies and antigen-binding fragments thereof, immunoadhesins, fusion proteins, oligopeptides, and other molecules that reduce, block, inhibit, eliminate, or interfere with the signal transduction generated by the interaction of PD-1 with PD-L1 and / or PD-L2. In one case, the PD-1 binding antagonist reduces the negative co-stimulatory signal mediated by the signal transduction of PD-1 mediated by or through cell surface proteins expressed on T lymphocytes, thereby making the dysfunctional T cells less dysfunctional (e.g., increasing the response of effectors to antigen recognition). In some cases, the PD-1 binding antagonist binds to PD-1. In some cases, the PD-1 binding antagonist is an anti-PD-1 antibody (e.g., an anti-PD-1 antagonist antibody). Exemplary anti-PD-1 antagonist antibodies include nivolumab, pembrolizumab, MEDI-0680, PDR001 (spartalizumab), REGN2810 (cemiprilimab), BGB-108, palolizumab, carrelizumab, sintilimab, tislelizumab, toripalimab, dotalimumab, rivulimab, sazanlimab, penampalimab, CS1003, HLX10, SCT-I10A, sepalizumab, batilizumab, genoluzumab, BI 754091, silimumab, YBL-006, BAT1306, HX008, brigalimumab, AMG 404, CX-188, JTX-4014, 609A, Sym021, LZM009, F520, SG001, AM0001, ENUM 244C8, ENUM 388D4, STI-1110, AK-103 and hAb21. In one specific aspect, the PD-1 binding antagonist is MDX-1106 (nivolumab). In another specific aspect, the PD-1 binding antagonist is MK-3475 (pembrolizumab). In another specific aspect, the PD-1 binding antagonist is a PD-L2 fusion protein, for example, AMP-224. In another specific aspect, the PD-1 binding antagonist is MED1-0680.In another specific aspect, the PD-1 binding antagonist is PDR001 (spartalizumab). In another specific aspect, the PD-1 binding antagonist is REGN2810 (simiprilimab). In another specific aspect, the PD-1 binding antagonist is BGB-108. In another specific aspect, the PD-1 binding antagonist is palolizumab. In another specific aspect, the PD-1 binding antagonist is carrelizumab. In another specific aspect, the PD-1 binding antagonist is sindilimab. In another specific aspect, the PD-1 binding antagonist is tislelizumab. In another specific aspect, the PD-1 binding antagonist is toripalizumab. Other additional exemplary PD-1 binding antagonists include BION-004, CB201, AUNP-012, ADG104 and LBL-006.

[0239] The term "PD-L2 binding antagonist" refers to a molecule that reduces, blocks, inhibits, eliminates or interferes with the signal transduction generated by the interaction of PD-L2 with one or more of its binding partners (such as PD-1). PD-L2 (programmed death ligand 2) is also referred to in the art as "programmed cell death 1 ligand 2", "PDCD1LG2", "CD273", "B7-DC", "Btdc" and "PDL2". Exemplary human PD-L2 is shown in UniProtKB / Swiss-Prot accession number Q9BQ51. In some cases, a PD-L2 binding antagonist is a molecule that inhibits the binding of PD-L2 to one or more of its binding partners. In a specific aspect, a PD-L2 binding antagonist inhibits the binding of PD-L2 to PD-1. Exemplary PD-L2 antagonists include anti-PD-L2 antibodies, antigen binding fragments thereof, immunoadhesins, fusion proteins, oligopeptides, and other molecules that reduce, block, inhibit, eliminate, or interfere with the signal transduction produced by the interaction of one or more of PD-L2 and its binding partner (such as PD-1). In one aspect, the PD-L2 binding antagonist reduces the negative co-stimulatory signal mediated by or expressed by the cell surface protein expressed on T lymphocytes, and the surface protein makes the dysfunctional T cell dysfunction less (for example, improving the response of the effector to antigen recognition) through the signal transduction mediated by PD-L2. In some aspects, the PD-L2 binding antagonist is combined with PD-L2. In some aspects, the PD-L2 binding antagonist is an immunoadhesin. In other aspects, the PD-L2 binding antagonist is an anti-PD-L2 antagonist antibody.

[0240] Unless otherwise indicated, the term "protein" as used herein refers to any native protein from any vertebrate source, including mammals such as primates (e.g., humans) and rodents (e.g., mice and rats). The term encompasses "full-length" unprocessed proteins, as well as any form of protein produced by processing in cells. The term also encompasses naturally occurring protein variants, such as splice variants or allelic variants.

[0241] "Amino acid sequence identity percentage (%)" relative to a reference polypeptide sequence is defined as the percentage of amino acid residues in the candidate sequence that are identical to the amino acid residues in the reference polypeptide sequence after aligning the candidate sequence with the reference polypeptide sequence and introducing spaces (if necessary) to achieve maximum sequence identity percentage, and for the purpose of alignment without considering any conservative substitutions as components of sequence identity. Alignment for determining amino acid sequence identity percentage can be achieved in various ways within the skill of the art, for example using publicly available computer software such as BLAST, BLAST-2, Clustal W, Megalign (DNASTAR) software or FASTA program packages. Those skilled in the art can determine appropriate parameters for aligning sequences, including any algorithm required for achieving maximum alignment over the full length of the compared sequence. Alternatively, the sequence comparison computer program ALIGN-2 can be used to generate identity percentage values. The ALIGN-2 sequence comparison computer program was written by Genentech, Inc. and the source code has been filed with user documentation in the US Copyright Office, Washington DC, 20559, where it is registered under US Copyright Registration No. TXU510087 and is described in WO 2001 / 007611.

[0242] Unless otherwise indicated, for the purposes of this article, the values ​​of percent amino acid sequence identity are generated using the BLOSUM50 comparison matrix using the ggsearch program of the FASTA package version 36.3.8c or higher. The FASTA package is by W.R. Pearson and D.J. Lipman (1988), "Improved Tools for Biological Sequence Analysis", PNAS 85:2444-2448; W.R. Pearson (1996) "Effective protein sequence comparison" Meth. Enzymol. 266:227-258; and Pearson et al. (1997) Genomics 46:24-36 creation and can be obtained from www.fasta.bioch.virginia.edu / fasta_www2 / fasta_down.shtml or www.ebi.ac.uk / Tools / sss / fasta. Alternatively, sequences can be compared using a public server accessible at fasta.bioch.virginia.edu / fasta_www2 / index.cgi, using the ggsearch (global protein:protein) program and default options (BLOSUM50; open: -10; ext: -2; Ktup = 2) to ensure that a global rather than a local alignment is performed. The amino acid identity percentage is given in the output alignment header.

[0243] The term "pharmaceutical formulation" refers to a preparation that is in a form that permits the biological activity of the active ingredient contained therein to be effective, and that contains no additional components that are unacceptably toxic to a subject to which the preparation would be administered.

[0244] "Pharmaceutically acceptable carrier" refers to a component of a pharmaceutical preparation other than the active ingredient that is non-toxic to the subject. Pharmaceutically acceptable carriers include, but are not limited to, buffers, excipients, stabilizers, or preservatives.

[0245] "Radiotherapy" refers to the use of directed gamma or beta rays to induce sufficient damage to cells to limit the ability of the cells to function normally or to completely destroy the cells. It will be understood that there are many known methods in the art to determine the dosage and duration of treatment. Typical treatment is a single administration, and a typical dosage range is 10 to 200 units (Gray) per day.

[0246] As used herein, "treatment" (and grammatical variations thereof, such as "treat" or "treating") refers to clinical intervention in an attempt to alter the natural course of the individual being treated, and can be performed for prevention or during the course of clinical pathology. Desired effects of treatment include, but are not limited to, preventing the occurrence or recurrence of disease, alleviating symptoms, diminishing any direct or indirect pathological consequences of disease, preventing metastasis, reducing the rate of disease progression, ameliorating or palliating the disease state, and alleviating or improving prognosis. In some aspects, the antibodies of the invention (e.g., the anti-FcRH5 / anti-CD3 TDBs of the invention) are used to delay the development of disease or slow the progression of disease.

[0247] "Reduce" or "inhibit" means the ability to cause an overall decrease, for example, an overall decrease of 20% or more, 50% or more, or 75%, 85%, 90%, 95% or more. In certain aspects, reduction or inhibition can refer to the effector function of an antibody mediated by the Fc region of the antibody, which effector function specifically includes complement dependent cytotoxicity (CDC), antibody dependent cellular toxicity (ADCC) and antibody dependent cellular phagocytosis (ADCP).

[0248] According to the present invention, the term "vaccine" refers to a pharmaceutical preparation (pharmaceutical composition) or product that induces an immune response after administration, particularly a cellular immune response that recognizes and attacks pathogens or diseased cells, such as cancer cells. Vaccines can be used to prevent or treat diseases. The vaccine can be a cancer vaccine. As used herein, a "cancer vaccine" is a composition that stimulates an immune response in a subject against cancer. Cancer vaccines are typically composed of cancer-related materials or cell (antigen) sources that may be autologous (from oneself) or allogeneic (from others) for the subject, together with other ingredients (e.g., adjuvants) to further stimulate and promote an immune response to the antigen. Cancer vaccines can result in stimulation of the subject's immune system to produce antibodies against one or more specific antigens, and / or produce killer T cells to attack cancer cells with those antigens.

[0249] As used herein, "administering" means a method of administering a dose of a compound (e.g., an anti-FcRH5 / anti-CD3 TDB of the present disclosure) to a subject. In some aspects, the composition used in the methods herein is administered intravenously. The composition used in the methods described herein can be administered, for example, intramuscularly, intravenously, intradermally, percutaneously, intraarterially, intraperitoneally, intralesionally, intracranially, intraarticularly, intraprostatically, intrapleurally, intratracheally, intranasally, intravitreally, intravaginally, intrarectally, topically, intratumorally, peritoneally, subcutaneously, subconjunctivally, intracapsularly, mucosally, intrapericardially, intraumbilically, intraocularly, orally, topically, topically, by inhalation, by injection, by infusion, by continuous infusion, by local perfusion directly to irrigate target cells, by catheter, by lavage, in the form of an emulsion or in the form of a lipid composition. The method of administration can vary depending on a variety of factors (e.g., the compound or composition to be administered and the severity of the condition, disease or disorder to be treated).

[0250] As used herein, "CD38" refers to the CD38 glycoprotein found on the surface of many immune cells (including CD4+, CD8+, B lymphocytes and natural killer (NK) cells), including any native CD38 from any vertebrate source, including mammals, such as primates (e.g., humans) and rodents (e.g., mice and rats), unless otherwise indicated. Compared with normal lymphoid and myeloid cells, the expression level of CD38 on myeloma cells is higher and more uniform. The term encompasses "full-length" unprocessed CD38, as well as any form of CD38 produced by processing in cells. The term also encompasses naturally occurring variants of CD38, such as splice variants or allelic variants. CD38 is also referred to in the art as differentiation cluster 38, ADP-ribosyl cyclase 1, cADPr hydrolase 1, and cyclic ADP-ribose hydrolase 1. CD38 is encoded by the CD38 gene. The nucleic acid sequence of an exemplary human CD38 is set forth in the following NCBI Reference Sequence: NM_001775.4 or in SEQ ID NO: 33. The amino acid sequence of an exemplary human CD38 protein encoded by CD38 is set forth in UniProt Accession No. P28907 or in SEQ ID NO:34.

[0251] The term "anti-CD38 antibody" encompasses all antibodies that bind to CD38 with sufficient affinity so that the antibody can be used as a therapeutic agent targeting cells expressing the antigen and does not significantly cross-react with other proteins (such as negative control proteins) in the assays described below. For example, anti-CD38 antibodies can bind to CD38 on the surface of MM cells and mediate cell lysis by activating complement-dependent cytotoxicity, ADCC, antibody-dependent cellular phagocytosis (ADCP), and Fc cross-linking-mediated apoptosis, leading to the consumption of malignant cells and a reduction in the overall cancer burden. Anti-CD38 antibodies can also modulate CD38 enzymatic activity by inhibiting ribosyl cyclase activity and stimulating the cyclic adenosine diphosphate ribose (cADPR) hydrolase activity of CD38. In certain aspects, the dissociation constant (K) of the anti-CD38 antibody bound to CD38 is D ) is ≤1 μM, ≤100 nM, ≤10 nM, ≤1 nM, ≤0.1 nM, ≤0.01 nM or ≤0.001 nM (e.g., 10 -8 M or smaller, e.g. 10 -8 M to 10 -13 M, for example 10 -9 M to 10 -13 M). In certain aspects, the anti-CD38 antibody can bind to both human CD38 and chimpanzee CD38. Anti-CD38 antibodies also include anti-CD38 antagonist antibodies. Bispecific antibodies in which one arm of the antibody binds CD38 are also contemplated. This definition of anti-CD38 antibodies also includes functional fragments of the foregoing antibodies. Examples of antibodies that bind to CD38 include: Daratumumab (U.S. Patent No.: 7,829,673 and U.S. Publication No.: 20160067205A1); "MOR202" (U.S. Patent No.: 8,263,746); and isatuximab (SAR-650984).

[0252] The terms "proliferation marker Ki-67," "Ki-67," and "MKI67" are used interchangeably and may refer to the MKI67 gene, transcript, or protein. MKI67 is a marker for cell proliferation (eg, a T cell proliferation marker).

[0253] The term "T cell proliferation marker" refers to any cell proliferation marker that can be detected in T cells. Exemplary T cell proliferation markers include, but are not limited to, MKI67, proliferating cell nuclear antigen (PCNA), minichromosome maintenance 2 (MCM2), incorporation of bromodeoxyuridine (BrdU), and other markers known in the art. In some instances, T cell proliferation markers are associated with cell division or DNA replication across multiple cell types. In other instances, T cell proliferation markers are specifically expressed in T cells but not in other cell types.

[0254] The terms "level" (as used in the context of "level of a T cell proliferation marker", "level of a cell proliferation marker", "reference level", "level of MKI67", "protein level" or "mRNA level"), "level of expression" and "expression level" are used interchangeably and generally refer to the amount of a polynucleotide (e.g., mRNA) or an amino acid product or protein in a biological sample. "Expression" generally refers to the process of converting genetically encoded information into a structure that exists and operates in a cell. Therefore, according to the present invention, the "expression" of a gene can refer to transcription into a polynucleotide, translation into a protein, or even post-translational modification of a protein. Fragments of transcribed polynucleotides, translated proteins, or post-translationally modified proteins should also be considered to have been expressed, whether they are derived from transcripts generated by alternative splicing or degradation of transcripts, or from post-translational processing of proteins (e.g., by proteolysis). "Expressed genes" include those that are transcribed into polynucleotides such as mRNA and then translated into polypeptides, as well as those that are transcribed into RNA but not translated into polypeptides (e.g., transfer RNA and ribosomal RNA).

[0255] As used herein, the term "marker" or "biomarker" refers to an indicator that can be detected in a sample, for example, a pharmacodynamic, predictive, diagnostic and / or prognostic indicator, for example, a T cell proliferation marker (e.g., MKI67, PCNA, MCM2, and molecules into which exogenous BrdU is incorporated). Biomarkers can be used as indicators of a specific subtype of a disease or disorder (e.g., cancer) characterized by certain characteristics, molecular characteristics, pathological characteristics, histological characteristics, and / or clinical characteristics. Biomarkers can be used as indicators of responses, for example, responses to treatments including bispecific anti-FcRH5 / anti-CD3 antibodies as disclosed herein (e.g., silvostomumab). In some embodiments, the biomarker is a gene. Biomarkers include, but are not limited to, polynucleotides (e.g., DNA and / or RNA), polynucleotide copy number changes (e.g., DNA copy number), polypeptides, polypeptide and polynucleotide modifications (e.g., post-translational modifications), carbohydrates, and / or glycolipid-based molecular markers.

[0256] As used herein, the term "sample" refers to a composition obtained or derived from a target subject and / or individual, which contains cells and / or other molecular entities to be characterized and / or identified, for example, based on physical, biochemical, chemical and / or physiological characteristics. Samples include, but are not limited to, tissue samples, primary or cultured cells or cell lines, cell supernatants, cell lysates, platelets, serum, plasma, vitreous humor, lymphatic fluid, synovial fluid, follicular fluid, semen, amniotic fluid, breast milk, whole blood, blood-derived cells, urine, cerebrospinal fluid, saliva, sputum, tears, sweat, mucus, tumor lysates and tissue culture media, tissue extracts such as homogenized tissues, tumor tissues, cell extracts, and combinations thereof.

[0257] As used herein, the term "reference level" refers to a level for comparison purposes. In some embodiments, the reference level is the level of MKI67 determined in a biological sample obtained from a subject before the bispecific antibody is administered to the subject (e.g., mRNA or protein level). In some embodiments, the reference level is obtained from a healthy and / or non-diseased body part (e.g., tissue or cell) of the same subject. For example, healthy and / or non-diseased cells or tissues are adjacent to diseased cells or tissues (e.g., cells or tissues adjacent to a tumor). In another embodiment, the reference level is obtained from untreated tissues and / or cells of the body of the same subject. In yet another embodiment, the reference level is obtained from a healthy and / or non-diseased body part (e.g., tissue or cell) of a subject that is not the subject. In yet another embodiment, the reference level is obtained from untreated tissues and / or cells of the body of an individual that is not the subject. In some embodiments, the reference level is the median protein level of a T cell proliferation marker determined in a population of individuals with MM. In some embodiments, the reference level is the median mRNA level of a T cell proliferation marker determined in a population of individuals with MM.

[0258] As used herein, the term "reference number" refers to the number of cells used for comparison purposes. In some embodiments, the reference number is the number of MKI67 cells determined in a biological sample obtained from a subject prior to administering the bispecific antibody to the subject. +In some embodiments, the reference quantity is obtained from a healthy and / or non-diseased body part (e.g., tissue or cell) of the same subject. For example, healthy and / or non-diseased cells are adjacent to diseased cells or tissues (e.g., cells or tissues adjacent to a tumor). In another embodiment, the reference quantity is obtained from untreated tissues and / or cells of the body of the same subject. In yet another embodiment, the reference quantity is obtained from a healthy and / or non-diseased body part (e.g., tissue or cell) of a subject that is not the subject. In yet another embodiment, the reference quantity is obtained from untreated tissues and / or cells of the body of an individual that is not the subject. In some embodiments, the reference quantity is the median number of cells expressing T cell proliferation markers determined in a population of individuals suffering from MM.

[0259] II. Treatment and diagnostic methods

[0260] The present invention is based in part on the discovery that in subjects with cancer (e.g., multiple myeloma (MM)) treated with a bispecific anti-crystallizable fragment receptor-like 5 (FcRH5) / anti-cluster of differentiation 3 (CD3) antibody in a fractionated, dose-escalating regimen, elevated levels of T cell proliferation markers and / or elevated MKI67 + The number of T cells is maintained. For example, as demonstrated herein, levels of the proliferation marker Ki-67 (MKI67) are elevated and maintained in responders (R) to a dosing regimen with a bispecific anti-FcRH5 / anti-CD3 antibody compared to non-responders (NR). The methods described herein allow for patient monitoring and assessment and can be used to inform treatment decisions, e.g., whether to continue a treatment including a bispecific anti-FcRH5 / anti-CD3 antibody or whether to select and / or administer a treatment that is not a bispecific anti-FcRH5 / anti-CD3 antibody or administer other treatments in addition to the administration of a bispecific anti-FcRH5 / anti-CD3 antibody. Therefore, these methods can be used to treat a subject while achieving a more favorable benefit-risk profile.

[0261] The present invention provides methods useful for treating a subject having cancer (e.g., MM) who has elevated levels of a T cell proliferation marker (e.g., MKI67) and / or elevated MKI67 + The method comprises the step of administering to the subject a bispecific antibody that binds to FcRH5 and CD3 (i.e., a bispecific anti-FcRH5 / anti-CD3 antibody), for example, in a divided dose ascending dosing regimen. In addition, the methods described herein can be used to monitor and assess the response of a subject undergoing a treatment described herein.

[0262] A. Monitoring Methods

[0263] The present invention provides methods for monitoring the response of a subject with cancer (e.g., MM) to treatment with a bispecific antibody. The subject may have elevated levels of a T cell proliferation marker (e.g., MKI67) and / or elevated MKI67 + The number of T cells. Treatment may include administering a bispecific antibody (eg, a bispecific anti-FcRH5 / anti-CD3 antibody) to the subject at a dosing regimen described herein (eg, a single-step ascending dosing regimen or a double-step ascending dosing regimen).

[0264] In some aspects, the method includes a step of determining the level of a T cell proliferation marker (e.g., MKI67) in a biological sample (e.g., blood, serum, or plasma) derived from a subject. The biological sample can be obtained from a subject (e.g., a human) with a cancer (e.g., MM) being treated with a bispecific antibody (e.g., a bispecific anti-FcRH5 / anti-CD3 antibody as described herein). In addition, the biological sample can be obtained from the subject at a time point after the bispecific antibody is administered. An exemplary time point after the administration of the bispecific antibody is 1 day or more (e.g., 2 days, 3 days, 4 days, 5 days, 6 days, 7 days, 8 days, 9 days, 10 days, 11 days, 12 days, 13 days, 14 days, 15 days, 16 days, 17 days, 18 days, 19 days, 20 days, 21 days, 22 days, 23 days, 24 days, 25 days, 26 days, 27 days, 28 days, 29 days, 30 days, 31 days or longer) after the bispecific antibody is administered.

[0265] In some aspects, the method comprises comparing the level of a T cell proliferation marker (e.g., MKI67) in a cell (e.g., a T cell) to a reference level, wherein an increase in the level of the T cell proliferation marker in the biological sample relative to the reference level identifies the subject as a subject responsive to the bispecific antibody, thereby monitoring the subject's response to treatment with the bispecific antibody.

[0266] In some aspects, provided herein is a method for monitoring the response of a subject having cancer (e.g., MM) to treatment with a bispecific antibody that binds to FcRH5 and CD3, the method comprising: (a) determining the level of a T cell proliferation marker in a biological sample obtained from the subject at a time point after administration of the bispecific antibody; and (b) comparing the level of the T cell proliferation marker in the biological sample to a reference level, wherein an increase in the level of the T cell proliferation marker in the biological sample relative to the reference level identifies the subject as a subject that is responsive to the bispecific antibody, thereby monitoring the subject's response to treatment with the bispecific antibody.

[0267] In some aspects, a bispecific antibody that binds to FcRH5 and CD3 is provided herein for use in the treatment of a subject with MM, the treatment comprising a step of monitoring the subject's response to treatment, the monitoring comprising: (a) determining the level of a T cell proliferation marker in a biological sample obtained from the subject at a time point after the bispecific antibody is administered; and (b) comparing the level of the T cell proliferation marker in the biological sample with a reference level, wherein the level of the T cell proliferation marker in the biological sample increases relative to the reference level, and the subject is identified as a subject who responds to the bispecific antibody, thereby monitoring the subject's response to treatment with the bispecific antibody. Any suitable reference level (e.g., baseline level) can be used. In some aspects, the reference level is the level (e.g., mRNA or protein level) of a T cell proliferation marker (e.g., MKI67) determined in a biological sample obtained from a subject before the bispecific antibody is administered to the subject. In some aspects, the biological sample is obtained from the subject at least 30 seconds (e.g., at least 1 minute, at least 2 minutes, at least 3 minutes, at least 4 minutes, at least 5 minutes, at least 10 minutes, at least 15 minutes, at least 30 minutes, at least 1 hour, at least 2 hours, at least 5 hours, at least 10 hours, at least 15 hours, at least 20 hours, or at least 24 hours) prior to administering the bispecific antibody to the subject. In some aspects, the biological sample is obtained from the subject at least 1 day (e.g., at least 2 days, at least 3 days, at least 4 days, at least 5 days, at least 6 days, at least 7 days, at least 8 days, at least 9 days, at least 10 days, at least 11 days, at least 12 days, at least 13 days, at least 14 days, at least 15 days, at least 16 days, at least 17 days, at least 18 days, at least 19 days, at least 20 days, at least 21 days, at least 22 days, at least 23 days, at least 24 days, at least 25 days, at least 26 days, at least 27 days, at least 28 days, at least 29 days, at least 30 days, at least 31 days or more) before the bispecific antibody is administered to the subject. In some aspects, the biological sample is obtained from the subject at least 1 week (e.g., at least 2 weeks, at least 3 weeks, at least 4 weeks, at least 5 weeks or more) before the bispecific antibody is administered to the subject.

[0268] In some aspects, the reference level is the median protein expression level of MKI67 determined in a population of individuals with MM. In some aspects, the reference level is the median mRNA expression level of MKI67 determined in a population of individuals with MM.

[0269] In some aspects, the reference level is less than 100% (e.g., 99%, 98%, 97%, 96%, 95%, 94%, 93%, 92%, 91%, 90%, 89%, 88%, 87%, 86%, 85%, 84%, 83%, 82%, 81%, 80%, 79%, 78%, 77%, 76%, 75%, 74%, 73%, 72%, 71%, 70%, 69%, 68%, 67%, 66%, 65%, 64%, 63%, 62%, 61%, 60%, 59%, 58%, 57%, 56%, 58%, 59%, 59% , 51%, 51%, 51%, 51%, 51%, 51%, 51%, 51%, 51%, 51%, 51%, 51%, 51%, 51%, 51%, 51%, 51%, 51%, 51%, 51%, 51%, 51%, 51%, 51%, 51%, 51%, 51%, 51%, 51%, 51%, 51%, 51%, 51%, 51%, 51%, 51%, 51%, 51%, 51%, 51%, 51%, 51%, 51%, 51%, 51%, 51%, 51%, 51%, %, 55%, 54%, 53%, 52%, 51%, 50%, 49%, 48%, 47%, 46%, 45%, 44%, 43%, 42%, 41%, 40%, 39%, 38%, 37%, 36%, 35%, 34%, 33%, 32%, 31%, 30%, 29%, 28%, 27%, 26%, 25%, 24%, 23%, 22%, 21%, 20%, 19%, 18%, 17%, 16%, 15%, 14%, 13%, 12%, 11%, 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1% or less). In some aspects, the reference level is about 50% to about 99% (e.g., about 55% to about 75%, about 60% to about 80%, about 65% to about 85%, about 75% to about 85%, about 85% to about 95%, or about 90% to about 99%) of the level of a T cell proliferation marker (e.g., MKI67) determined in a biological sample obtained from a subject prior to administration of the bispecific antibody. In some aspects, the reference level is about 1% to about 50% (e.g., about 1% to about 20%, about 5% to about 25%, about 10% to about 30%, about 20% to about 40%, about 25% to about 45%, or about 45% to about 50%) of the level of a T cell proliferation marker (e.g., MKI67) determined in a biological sample obtained from a subject prior to administration of the bispecific antibody. In some aspects, the reference level is about 0.01% to about 1% (e.g., about 0.05% to about 0.01%, about 0.01% to about 0.5%, or about .5% to about 1%) of the level of a T cell proliferation marker (e.g., MKI67) determined in a biological sample obtained from a subject prior to administration of the bispecific antibody.

[0270] In some aspects, the level of a T cell proliferation marker (e.g., MKI67) is greater than 100% of a reference level (e.g., 101%, 105%, 110%, 120%, 150%, 200%, 250%, 300% or greater). In some aspects, the level of a T cell proliferation marker (e.g., MKI67) is between about 101% and about 1000% of a reference level (e.g., about 101% to about 500%, about 200% to about 400%, about 300% to about 600%, about 400% to about 700%, about 500% to about 800%, about 600% to about 900%, or about 700% to about 1000%). In some aspects, the level of a T cell proliferation marker (e.g., MKI67) is between about 101% and about 500% of a reference level (e.g., about 101% to about 500%, about 101% to about 400%, about 101% to about 300%, or about 101% to about 200%).

[0271] In some aspects, the level of a T cell proliferation marker (e.g., MKI67) is greater than 1-fold higher relative to a reference level (e.g., 1.1-fold higher, 1.2-fold higher, 1.3-fold higher, 1.4-fold higher, 1.5-fold higher, 1.6-fold higher, 1.7-fold higher, 1.8-fold higher, 1.9-fold higher, 2-fold higher, 2.5-fold higher, 3-fold higher, 3.5-fold higher, 4-fold higher, 4.5-fold higher, 5-fold higher, 5.5-fold higher, 6-fold higher, 6.5-fold higher, 7-fold higher, 7.5-fold higher, 8-fold higher, 8.5-fold higher, 9-fold higher, 9.5-fold higher, 10-fold higher, or more). In some aspects, the level of a T cell proliferation marker (e.g., MKI67) is about 1.1 times to about 5 times higher relative to a reference level (e.g., about 1.2 times to about 2 times higher, about 1.5 times to about 3 times higher, about 2.5 times to about 4 times higher, or about 4 times to about 5 times higher). In some aspects, the level of a T cell proliferation marker (e.g., MKI67) is about 2 times to about 10 times higher relative to a reference level (e.g., about 2 times to about 4 times higher, about 3 times to about 5 times higher, about 5 times to about 7 times higher, about 6 times to about 8 times higher, or about 7 times to about 10 times higher). In some aspects, the level of a T cell proliferation marker (e.g., MKI67) is about 5 times to about 10 times higher relative to a reference level (e.g., about 5 times to about 6 times higher, about 6 times to about 7 times higher, about 7 times to about 8 times higher, about 8 times to about 9 times higher, or about 9 times to about 10 times higher).

[0272] In some aspects, the method can further include administering a bispecific antibody (eg, a bispecific anti-FcRH5 / anti-CD3 antibody described herein) to the subject. In some examples, the bispecific antibody is sivostatin.

[0273] In some aspects, T cell proliferation markers (e.g., MKI67) are protein levels. Any suitable laboratory technique for determining protein levels in a sample can be used, including but not limited to flow cytometry (FC), fluorescence activated cell sorting (FACS) Western blot, enzyme-linked immunosorbent assay (ELISA), mass spectrometry (MS), immunofluorescence (IF), immunoprecipitation (IP), radioimmunoassay, dot blot, high performance liquid chromatography (HPLC), surface plasmon resonance, spectroscopy, and immunohistochemistry (IHC). Any immune-based technique may include the use of MKI67 antibodies, such as monoclonal Ki-67 antibodies or MIB-1 antibodies.

[0274] In some aspects, the T cell proliferation marker (e.g., MKI67) is mRNA level. Any suitable laboratory technique for determining protein expression levels in a sample can be used, including but not limited to polymerase chain reaction (PCR), reverse transcription-PCR (RT-PCR), quantitative-PCR (qPCR), RT-qPCR, microarray analysis, Northern blot, techniques, serial analysis of gene expression (SAGE) and RNA sequencing.

[0275] In some aspects, a T cell proliferation marker (eg, MKI67) is detected in a T cell in a biological sample. The T cell may be MKI67 + T cells and / or granzyme B (Gzb) positive (Gzb + )T cells.

[0276] In some aspects, the invention provides methods for monitoring the response of a subject having cancer (eg, MM) to treatment with a bispecific antibody. The subject may have elevated MKI67 + Cells (e.g., MKI67 + The treatment may include administering a bispecific antibody (eg, a bispecific anti-FcRH5 / anti-CD3 antibody) to the subject at a dosing regimen described herein (eg, a single-step ascending dosing regimen or a double-step ascending dosing regimen).

[0277] In some aspects, the method comprises determining whether MKI67 is positive (MKI67 + ) cells (e.g., MKI67 +The biological sample can be obtained from a subject (e.g., a human) with cancer (e.g., MM) being treated with a bispecific antibody (e.g., a bispecific anti-FcRH5 / anti-CD3 antibody described herein). In addition, the biological sample can be obtained from the subject at a time point after administration of the bispecific antibody. Exemplary time points after administration of the bispecific antibody are 1 or more days (e.g., 2 days, 3 days, 4 days, 5 days, 6 days, 7 days, 8 days, 9 days, 10 days, 11 days, 12 days, 13 days, 14 days, 15 days, 16 days, 17 days, 18 days, 19 days, 20 days, 21 days, 22 days, 23 days, 24 days, 25 days, 26 days, 27 days, 28 days, 29 days, 30 days, 31 days or longer) after administration of the bispecific antibody.

[0278] In some aspects, the method further comprises converting MKI67 + Cells (e.g., MKI67 + T cells) is compared to a reference number, wherein the MKI67 in the biological sample is greater than the reference number. + If the number of T cells (e.g., T cells) increases, the subject is identified as a subject that has responded to the bispecific antibody, thereby monitoring the subject's response to treatment with the bispecific antibody.

[0279] In some aspects, provided herein is a method for monitoring the response of a subject having cancer (e.g., MM) to treatment with a bispecific antibody that binds to FcRH5 and CD3, the method comprising: (a) determining the level of MKI67 in a biological sample obtained from the subject at a time point after administration of the bispecific antibody; + T cell count; and (b) MKI67 in biological samples + The number of T cells is compared to a reference number, where the MKI67 in the biological sample is higher relative to the reference number. + If the number of T cells increases, the subject is identified as a subject that has responded to the bispecific antibody, thereby monitoring the subject's response to treatment with the bispecific antibody.

[0280] In some aspects, provided herein is a bispecific antibody that binds to FcRH5 and CD3 for use in treating a subject with MM, the treatment comprising the step of monitoring the subject's response to the treatment, the monitoring comprising: (a) determining the level of MKI67 in a biological sample obtained from the subject at a time point after administration of the bispecific antibody; + T cell count; and (b) MKI67 in biological samples + The number of T cells is compared to a reference number, where the MKI67 in the biological sample is higher relative to the reference number. +If the number of T cells increases, the subject is identified as a subject that has responded to the bispecific antibody, thereby monitoring the subject's response to treatment with the bispecific antibody.

[0281] Any suitable reference amount (eg, a baseline level) can be used. In some aspects, the reference amount is MKI67 determined in a biological sample obtained from a subject prior to administering the bispecific antibody to the subject. + Cells (e.g., MKI67 + In some aspects, the biological sample is obtained from the subject at least 30 seconds (e.g., at least 1 minute, at least 2 minutes, at least 3 minutes, at least 4 minutes, at least 5 minutes, at least 10 minutes, at least 15 minutes, at least 30 minutes, at least 1 hour, at least 2 hours, at least 5 hours, at least 10 hours, at least 15 hours, at least 20 hours, or at least 24 hours) prior to administering the bispecific antibody to the subject. In some aspects, the biological sample is obtained from the subject at least 1 day (e.g., at least 2 days, at least 3 days, at least 4 days, at least 5 days, at least 6 days, at least 7 days, at least 8 days, at least 9 days, at least 10 days, at least 11 days, at least 12 days, at least 13 days, at least 14 days, at least 15 days, at least 16 days, at least 17 days, at least 18 days, at least 19 days, at least 20 days, at least 21 days, at least 22 days, at least 23 days, at least 24 days, at least 25 days, at least 26 days, at least 27 days, at least 28 days, at least 29 days, at least 30 days, at least 31 days or more) before the bispecific antibody is administered to the subject. In some aspects, the biological sample is obtained from the subject at least 1 week (e.g., at least 2 weeks, at least 3 weeks, at least 4 weeks, at least 5 weeks or more) before the bispecific antibody is administered to the subject.

[0282] In some aspects, the reference amount is MKI67 determined in a population of individuals with MM. + Cells (e.g., MKI67 + In some embodiments, the reference number is less than the median number of MKI67 T cells determined in a biological sample obtained from a subject prior to administration of the bispecific antibody. + Cells (e.g., MKI67 +100% (e.g., 99%, 98%, 97%, 96%, 95%, 94%, 93%, 92%, 91%, 90%, 89%, 88%, 87%, 86%, 85%, 84%, 83%, 82%, 81%, 80%, 79%, 78%, 77%, 76%, 75%, 74%, 73%, 72%, 71%, 70%, 69%, 68%, 67%, 66%, 65%, 64%, 63%, 62%, 61%, 60%, 59%, 58%, 57%, 56%, 55%, 54%, 53% of the number of T cells) %, 52%, 51%, 50%, 49%, 48%, 47%, 46%, 45%, 44%, 43%, 42%, 41%, 40%, 39%, 38%, 37%, 36%, 35%, 34%, 33%, 32%, 31%, 30%, 29%, 28%, 27%, 26%, 25%, 24%, 23%, 22%, 21%, 20%, 19%, 18%, 17%, 16%, 15%, 14%, 13%, 12%, 11%, 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1% or less). In some aspects, the reference amount is MKI67 determined in a biological sample obtained from the subject prior to administration of the bispecific antibody. + Cells (e.g., MKI67 + T cells) (e.g., about 55% to about 75%, about 60% to about 80%, about 65% to about 85%, about 75% to about 85%, about 85% to about 95%, or about 90% to about 99%). In some aspects, the reference amount is the MKI67 T cell population determined in a biological sample obtained from the subject prior to administration of the bispecific antibody. + Cells (e.g., MKI67 + T cells) (e.g., about 1% to about 20%, about 5% to about 25%, about 10% to about 30%, about 20% to about 40%, about 25% to about 45%, or about 45% to about 50%). In some aspects, the reference amount is the MKI67 T cell population determined in a biological sample obtained from the subject prior to administration of the bispecific antibody. + Cells (e.g., MKI67 + T cells) (eg, about 0.05% to about 0.01%, about 0.01% to about 0.5%, or about 0.5% to about 1%).

[0283] In some aspects, MKI67 + Cells (e.g., MKI67 +T cells) is greater than 100% (e.g., 101%, 105%, 110%, 120%, 150%, 200%, 250%, 300% or more) of the reference number. In some aspects, MKI67 + Cells (e.g., MKI67 + T cells) is between about 101% and about 1000% of a reference number (e.g., about 101% to about 500%, about 200% to about 400%, about 300% to about 600%, about 400% to about 700%, about 500% to about 800%, about 600% to about 900%, or about 700% to about 1000%). In some aspects, MKI67 + Cells (e.g., MKI67 + T cells) is between about 101% and about 500% of a reference number (e.g., about 101% to about 500%, about 101% to about 400%, about 101% to about 300%, or about 101% to about 200%).

[0284] In some aspects, MKI67 + Cells (e.g., MKI67 + In some aspects, the number of MKI67 T cells is greater than 1-fold higher (e.g., 1.1-fold higher, 1.2-fold higher, 1.3-fold higher, 1.4-fold higher, 1.5-fold higher, 1.6-fold higher, 1.7-fold higher, 1.8-fold higher, 1.9-fold higher, 2-fold higher, 2.5-fold higher, 3-fold higher, 3.5-fold higher, 4-fold higher, 4.5-fold higher, 5-fold higher, 5.5-fold higher, 6-fold higher, 6.5-fold higher, 7-fold higher, 7.5-fold higher, 8-fold higher, 8.5-fold higher, 9-fold higher, 9.5-fold higher, 10-fold higher or more) relative to a reference number. + Cells (e.g., MKI67 + T cells) is about 1.1-fold to about 5-fold higher (e.g., about 1.2-fold to about 2-fold higher, about 1.5-fold to about 3-fold higher, about 2.5-fold to about 4-fold higher, or about 4-fold to about 5-fold higher) relative to a reference number. In some aspects, MKI67 + Cells (e.g., MKI67 + T cells) relative to a reference number by about 2-fold to about 10-fold (e.g., about 2-fold to about 4-fold, about 3-fold to about 5-fold, about 5-fold to about 7-fold, about 6-fold to about 8-fold, or about 7-fold to about 10-fold). In some aspects, MKI67 + Cells (e.g., MKI67 +T cells) is about 5-fold to about 10-fold higher (e.g., about 5-fold to about 6-fold higher, about 6-fold to about 7-fold higher, about 7-fold to about 8-fold higher, about 8-fold to about 9-fold higher, or about 9-fold to about 10-fold higher) relative to a reference number.

[0285] In some aspects, MKI67 in a sample + Cells (e.g., MKI67 + The number of T cells) is detected by, for example, FC, FACS, Western blot, ELISA, MS, IF, IP, radioimmunoassay, dot blot, HPLC, surface plasmon resonance, spectroscopy or IHC. Any immune-based technique may include the use of MKI67 antibodies, such as monoclonal Ki-67 antibodies or MIB-1 antibodies.

[0286] In some aspects, MKI67 + MKI67 + T cells and / or Gzb + T cells.

[0287] In some aspects, the method can further include administering a bispecific antibody (eg, a bispecific anti-FcRH5 / anti-CD3 antibody described herein) to the subject. In some examples, the bispecific antibody is sivostatin.

[0288] B. Assessment Method

[0289] The present invention provides a method for assessing the response of a subject with cancer (e.g., MM) to treatment with a bispecific antibody. The subject may have an elevated level of a T cell proliferation marker (e.g., MKI67). Treatment may include administering a bispecific antibody (e.g., a bispecific anti-FcRH5 / anti-CD3 antibody) to the subject with a dosing regimen described herein (e.g., a single-step ascending dosing regimen or a double-step ascending dosing regimen).

[0290] In some aspects, the method includes a step of determining the level of a T cell proliferation marker (e.g., MKI67) in a biological sample (e.g., blood, serum, or plasma) derived from a subject. The biological sample can be obtained from a subject (e.g., a human) with a cancer (e.g., MM) being treated with a bispecific antibody (e.g., a bispecific anti-FcRH5 / anti-CD3 antibody as described herein). In addition, the biological sample can be obtained from the subject at a time point after the bispecific antibody is administered. An exemplary time point after the administration of the bispecific antibody is 1 day or more (e.g., 2 days, 3 days, 4 days, 5 days, 6 days, 7 days, 8 days, 9 days, 10 days, 11 days, 12 days, 13 days, 14 days, 15 days, 16 days, 17 days, 18 days, 19 days, 20 days, 21 days, 22 days, 23 days, 24 days, 25 days, 26 days, 27 days, 28 days, 29 days, 30 days, 31 days or longer) after the bispecific antibody is administered.

[0291] In some aspects, the method further comprises maintaining, adjusting, or stopping treatment of the subject based on a comparison of the level of a T cell proliferation marker (e.g., MKI67) in the biological sample to a reference level, wherein a change in the level of the T cell proliferation marker in the biological sample compared to the reference level indicates a response to treatment with the bispecific antibody.

[0292] In some aspects, provided herein is a method for assessing a therapeutic response of a subject having cancer (e.g., MM) to treatment with a bispecific antibody that binds to FcRH5 and CD3, the method comprising: (a) determining the level of a T cell proliferation marker in a biological sample obtained from the subject at a time point after administration of the bispecific antibody; and (b) maintaining, adjusting, or stopping treatment of the subject based on a comparison of the level of the T cell proliferation marker in the biological sample with a reference level, wherein a change in the level of the T cell proliferation marker in the biological sample compared to the reference level indicates a response to treatment with the bispecific antibody.

[0293] In some aspects, the method can further include administering a bispecific antibody (eg, a bispecific anti-FcRH5 / anti-CD3 antibody described herein) to the subject. In some examples, the bispecific antibody is sivostatin.

[0294] In some aspects, if the level of a T cell proliferation marker (e.g., MKI67) in a biological sample increases relative to a reference level, the subject responds to treatment and the treatment is maintained. In other aspects, if the level of a T cell proliferation marker (e.g., MKI67) in a biological sample is the same or decreases relative to a reference level, the subject does not respond to treatment and the treatment is adjusted or stopped.

[0295] In some aspects, provided herein is a bispecific antibody that binds to FcRH5 and CD3 for use in the treatment of a subject with MM, the treatment comprising the step of assessing the subject's response to the treatment, the assessment comprising: (a) determining the level of a T cell proliferation marker in a biological sample obtained from the subject at a time point after administration of the bispecific antibody; and (b) maintaining, adjusting, or stopping the subject's treatment based on a comparison of the level of the T cell proliferation marker in the biological sample with a reference level, wherein a change in the level of the T cell proliferation marker in the biological sample compared to the reference level indicates a response to treatment with the bispecific antibody.

[0296] Any suitable reference level (e.g., baseline level) can be used. In some aspects, the reference level is the level (e.g., mRNA or protein level) of a T cell proliferation marker (e.g., MKI67) determined in a biological sample obtained from a subject before the bispecific antibody is administered to the subject. In some aspects, the biological sample is obtained from a subject at least 30 seconds (e.g., at least 1 minute, at least 2 minutes, at least 3 minutes, at least 4 minutes, at least 5 minutes, at least 10 minutes, at least 15 minutes, at least 30 minutes, at least 1 hour, at least 2 hours, at least 5 hours, at least 10 hours, at least 15 hours, at least 20 hours, or at least 24 hours) before the bispecific antibody is administered to the subject. In some aspects, the biological sample is obtained from the subject at least 1 day (e.g., at least 2 days, at least 3 days, at least 4 days, at least 5 days, at least 6 days, at least 7 days, at least 8 days, at least 9 days, at least 10 days, at least 11 days, at least 12 days, at least 13 days, at least 14 days, at least 15 days, at least 16 days, at least 17 days, at least 18 days, at least 19 days, at least 20 days, at least 21 days, at least 22 days, at least 23 days, at least 24 days, at least 25 days, at least 26 days, at least 27 days, at least 28 days, at least 29 days, at least 30 days, at least 31 days or more) before the bispecific antibody is administered to the subject. In some aspects, the biological sample is obtained from the subject at least 1 week (e.g., at least 2 weeks, at least 3 weeks, at least 4 weeks, at least 5 weeks or more) before the bispecific antibody is administered to the subject.

[0297] In some aspects, the reference level is the median protein expression level of MKI67 determined in a population of individuals with MM. In some aspects, the reference level is the median mRNA expression level of MKI67 determined in a population of individuals with MM. In some aspects, the reference level is less than 100% (e.g., 99%, 98%, 97%, 96%, 95%, 94%, 93%, 92%, 91%, 90%, 89%, 88%, 87%, 86%, 85%, 84%, 83%, 82%, 81%, 80%, 79%, 78%, 77%, 76%, 75%, 74%, 73%, 72%, 71%, 70%, 69%, 68%, 67%, 66%, 65%, 64%, 63%, 62%, 61%, 60%, 69%, 61%, 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69%, 69%, 69%, 69%, 69%, 69%, 69%, 69%, 69%, 60%, 69%, 60%, 60%, 60%, 60%, 60%, 60%, 60%, 60%, 60%, 60%, 60%, 60%, 60%, 60%, 60%, 60%, 60%, 60%, 60%, 60%, 60%, 60%, 60%, 60%, 60%, 60%, 60%, 60%, 60%, 60%, 60%, 60%, 60%, 60%, 60%, %, 58%, 57%, 56%, 55%, 54%, 53%, 52%, 51%, 50%, 49%, 48%, 47%, 46%, 45%, 44%, 43%, 42%, 41%, 40%, 39%, 38%, 37%, 36%, 35%, 34%, 33%, 32%, 31%, 30%, 29%, 28%, 27%, 26%, 25%, 24%, 23%, 22%, 21%, 20%, 19%, 18%, 17%, 16%, 15%, 14%, 13%, 12%, 11%, 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1% or less). In some aspects, the reference level is about 50% to about 99% (e.g., about 55% to about 75%, about 60% to about 80%, about 65% to about 85%, about 75% to about 85%, about 85% to about 95%, or about 90% to about 99%) of the level of a T cell proliferation marker (e.g., MKI67) determined in a biological sample obtained from a subject prior to administration of the bispecific antibody. In some aspects, the reference level is about 1% to about 50% (e.g., about 1% to about 20%, about 5% to about 25%, about 10% to about 30%, about 20% to about 40%, about 25% to about 45%, or about 45% to about 50%) of the level of a T cell proliferation marker (e.g., MKI67) determined in a biological sample obtained from a subject prior to administration of the bispecific antibody. In some aspects, the reference level is about 0.01% to about 1% (e.g., about 0.05% to about 0.01%, about 0.01% to about 0.5%, or about .5% to about 1%) of the level of a T cell proliferation marker (e.g., MKI67) determined in a biological sample obtained from a subject prior to administration of the bispecific antibody.

[0298] In some aspects, the level of a T cell proliferation marker (e.g., MKI67) is greater than 100% of a reference level (e.g., 101%, 105%, 110%, 120%, 150%, 200%, 250%, 300% or greater). In some aspects, the level of a T cell proliferation marker (e.g., MKI67) is between about 101% and about 1000% of a reference level (e.g., about 101% to about 500%, about 200% to about 400%, about 300% to about 600%, about 400% to about 700%, about 500% to about 800%, about 600% to about 900%, or about 700% to about 1000%). In some aspects, the level of a T cell proliferation marker (e.g., MKI67) is between about 101% and about 500% of a reference level (e.g., about 101% to about 500%, about 101% to about 400%, about 101% to about 300%, or about 101% to about 200%).

[0299] In some aspects, the level of a T cell proliferation marker (e.g., MKI67) is greater than 1-fold higher relative to a reference level (e.g., 1.1-fold higher, 1.2-fold higher, 1.3-fold higher, 1.4-fold higher, 1.5-fold higher, 1.6-fold higher, 1.7-fold higher, 1.8-fold higher, 1.9-fold higher, 2-fold higher, 2.5-fold higher, 3-fold higher, 3.5-fold higher, 4-fold higher, 4.5-fold higher, 5-fold higher, 5.5-fold higher, 6-fold higher, 6.5-fold higher, 7-fold higher, 7.5-fold higher, 8-fold higher, 8.5-fold higher, 9-fold higher, 9.5-fold higher, 10-fold higher, or more). In some aspects, the level of a T cell proliferation marker (e.g., MKI67) is about 1.1 times to about 5 times higher relative to a reference level (e.g., about 1.2 times to about 2 times higher, about 1.5 times to about 3 times higher, about 2.5 times to about 4 times higher, or about 4 times to about 5 times higher). In some aspects, the level of a T cell proliferation marker (e.g., MKI67) is about 2 times to about 10 times higher relative to a reference level (e.g., about 2 times to about 4 times higher, about 3 times to about 5 times higher, about 5 times to about 7 times higher, about 6 times to about 8 times higher, or about 7 times to about 10 times higher). In some aspects, the level of a T cell proliferation marker (e.g., MKI67) is about 5 times to about 10 times higher relative to a reference level (e.g., about 5 times to about 6 times higher, about 6 times to about 7 times higher, about 7 times to about 8 times higher, about 8 times to about 9 times higher, or about 9 times to about 10 times higher).

[0300] In some aspects, the method can further include administering a bispecific antibody (eg, a bispecific anti-FcRH5 / anti-CD3 antibody described herein) to the subject. In some examples, the bispecific antibody is sivostatin.

[0301] In some aspects, the T cell proliferation marker (e.g., MKI67) is a protein level. Any suitable laboratory technique for determining protein levels in a sample can be used, including but not limited to FC, FACS, Western blot, ELISA, MS, IF, IP, radioimmunoassay, dot blot, HPLC, surface plasmon resonance, spectroscopy, and IHC. Any immune-based technique may include the use of an MKI67 antibody, such as a monoclonal Ki-67 antibody or a MIB-1 antibody.

[0302] In some aspects, the T cell proliferation marker (e.g., MKI67) is mRNA level. Any suitable laboratory technique for determining protein expression levels in a sample can be used, including but not limited to PCR, RT-PCR, qPCR, RT-qPCR, microarray analysis, Northern blot, technology, SAGE and RNA sequencing.

[0303] In some aspects, a T cell proliferation marker (eg, MKI67) is detected in a T cell in a biological sample. The T cell may be MKI67 + T cells and / or granzyme B (Gzb) positive (Gzb + )T cells.

[0304] In some aspects, a T cell proliferation marker (eg, MKI67) is detected in a T cell in a biological sample. The T cell may be MKI67 + T cells and / or Gzb + T cells.

[0305] In some aspects, the invention provides methods for assessing the response of a subject having cancer (eg, MM) to treatment with a bispecific antibody. The subject may have elevated MKI67 + Cells (e.g., MKI67 + The treatment may include administering a bispecific antibody (eg, a bispecific anti-FcRH5 / anti-CD3 antibody) to the subject at a dosing regimen described herein (eg, a single-step ascending dosing regimen or a double-step ascending dosing regimen).

[0306] In some aspects, the method comprises determining the expression of MKI67 in a biological sample (eg, blood, serum, or plasma) derived from the subject. + Cells (e.g., MKI67 +The biological sample can be obtained from a subject (e.g., a human) with cancer (e.g., MM) being treated with a bispecific antibody (e.g., a bispecific anti-FcRH5 / anti-CD3 antibody described herein). In addition, the biological sample can be obtained from the subject at a time point after administration of the bispecific antibody. Exemplary time points after administration of the bispecific antibody are 1 or more days (e.g., 2 days, 3 days, 4 days, 5 days, 6 days, 7 days, 8 days, 9 days, 10 days, 11 days, 12 days, 13 days, 14 days, 15 days, 16 days, 17 days, 18 days, 19 days, 20 days, 21 days, 22 days, 23 days, 24 days, 25 days, 26 days, 27 days, 28 days, 29 days, 30 days, 31 days or longer) after administration of the bispecific antibody.

[0307] In some aspects, the method further comprises the step of: determining the expression of MKI67 in the biological sample based on the expression of MKI67 in the biological sample; + Cells (e.g., MKI67 + T cells) in the biological sample compared to a reference number to maintain, adjust or stop treatment of the subject, wherein the MKI67 in the biological sample is increased compared to the reference number. + Cells (e.g., MKI67 + Changes in the number of T cells) indicate a response to treatment with the bispecific antibody.

[0308] In some aspects, provided herein is a method for assessing a therapeutic response of a subject having cancer (e.g., MM) to treatment with a bispecific antibody that binds to FcRH5 and CD3, the method comprising: (a) determining the level of MKI67 in a biological sample obtained from the subject at a time point after administration of the bispecific antibody; + T cell count; and (b) based on MKI67 in biological samples + T cells in the biological sample are compared to a reference number to maintain, adjust or stop treatment of the subject, wherein the MKI67 in the biological sample is compared to the reference number. + Changes in the number of T cells indicate a response to treatment with the bispecific antibody.

[0309] In some aspects, provided herein is a bispecific antibody that binds to FcRH5 and CD3 for use in the treatment of a subject with MM, the treatment comprising the step of assessing the subject's response to the treatment, the assessment comprising: (a) determining the level of MKI67 in a biological sample obtained from the subject at a time point after administration of the bispecific antibody; + T cell count; and (b) based on MKI67 in biological samples + T cells in the biological sample are compared to a reference number to maintain, adjust or stop treatment of the subject, wherein the MKI67 in the biological sample is compared to the reference number.+ Changes in the number of T cells indicate a response to treatment with the bispecific antibody.

[0310] Any suitable reference amount (eg, a baseline level) can be used. In some aspects, the reference amount is MKI67 determined in a biological sample obtained from a subject prior to administering the bispecific antibody to the subject. + Cells (e.g., MKI67 + In some aspects, the biological sample is obtained from the subject at least 30 seconds (e.g., at least 1 minute, at least 2 minutes, at least 3 minutes, at least 4 minutes, at least 5 minutes, at least 10 minutes, at least 15 minutes, at least 30 minutes, at least 1 hour, at least 2 hours, at least 5 hours, at least 10 hours, at least 15 hours, at least 20 hours, or at least 24 hours) prior to administering the bispecific antibody to the subject. In some aspects, the biological sample is obtained from the subject at least 1 day (e.g., at least 2 days, at least 3 days, at least 4 days, at least 5 days, at least 6 days, at least 7 days, at least 8 days, at least 9 days, at least 10 days, at least 11 days, at least 12 days, at least 13 days, at least 14 days, at least 15 days, at least 16 days, at least 17 days, at least 18 days, at least 19 days, at least 20 days, at least 21 days, at least 22 days, at least 23 days, at least 24 days, at least 25 days, at least 26 days, at least 27 days, at least 28 days, at least 29 days, at least 30 days, at least 31 days or more) before the bispecific antibody is administered to the subject. In some aspects, the biological sample is obtained from the subject at least 1 week (e.g., at least 2 weeks, at least 3 weeks, at least 4 weeks, at least 5 weeks or more) before the bispecific antibody is administered to the subject.

[0311] In some aspects, the reference amount is MKI67 determined in a population of individuals with MM. + Cells (e.g., MKI67 + In some embodiments, the reference amount is less than the median number of MKI67 T cells measured in subjects being treated with the bispecific antibody and / or being assessed or monitored after treatment. +100% of the number of T cells (e.g., 99%, 98%, 97%, 96%, 95%, 94%, 93%, 92%, 91%, 90%, 89%, 88%, 87%, 86%, 85%, 84%, 83%, 82%, 81%, 80%, 79%, 78%, 77%, 76%, 75%, 74%, 73%, 72%, 71%, 70%, 69%, 68%, 67%, 66%, 65%, 64%, 63%, 62%, 61%, 60%, 59%, 58%, 57%, 56%, 55%, 54%, 53%, 54%, 55%, 56%, 57%, 58%, 59 ... %, 52%, 51%, 50%, 49%, 48%, 47%, 46%, 45%, 44%, 43%, 42%, 41%, 40%, 39%, 38%, 37%, 36%, 35%, 34%, 33%, 32%, 31%, 30%, 29%, 28%, 27%, 26%, 25%, 24%, 23%, 22%, 21%, 20%, 19%, 18%, 17%, 16%, 15%, 14%, 13%, 12%, 11%, 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1% or less). In some aspects, the reference amount is MKI67 determined in a biological sample obtained from the subject prior to administration of the bispecific antibody. + Cells (e.g., MKI67 + T cells) (e.g., about 55% to about 75%, about 60% to about 80%, about 65% to about 85%, about 75% to about 85%, about 85% to about 95%, or about 90% to about 99%). In some aspects, the reference amount is the MKI67 T cell population determined in a biological sample obtained from the subject prior to administration of the bispecific antibody. + Cells (e.g., MKI67 + T cells) (e.g., about 1% to about 20%, about 5% to about 25%, about 10% to about 30%, about 20% to about 40%, about 25% to about 45%, or about 45% to about 50%). In some aspects, the reference amount is the MKI67 T cell population determined in a biological sample obtained from the subject prior to administration of the bispecific antibody. + Cells (e.g., MKI67 + T cells) (eg, about 0.05% to about 0.01%, about 0.01% to about 0.5%, or about 0.5% to about 1%).

[0312] In some aspects, MKI67 + Cells (e.g., MKI67 +T cells) is greater than 100% (e.g., 101%, 105%, 110%, 120%, 150%, 200%, 250%, 300% or more) of the reference number. In some aspects, MKI67 + Cells (e.g., MKI67 + T cells) is between about 101% and about 1000% of a reference number (e.g., about 101% to about 500%, about 200% to about 400%, about 300% to about 600%, about 400% to about 700%, about 500% to about 800%, about 600% to about 900%, or about 700% to about 1000%). In some aspects, MKI67 + Cells (e.g., MKI67 + T cells) is between about 101% and about 500% of a reference number (e.g., about 101% to about 500%, about 101% to about 400%, about 101% to about 300%, or about 101% to about 200%).

[0313] In some aspects, MKI67 + Cells (e.g., MKI67 + In some aspects, the number of MKI67 T cells is greater than 1-fold higher (e.g., 1.1-fold higher, 1.2-fold higher, 1.3-fold higher, 1.4-fold higher, 1.5-fold higher, 1.6-fold higher, 1.7-fold higher, 1.8-fold higher, 1.9-fold higher, 2-fold higher, 2.5-fold higher, 3-fold higher, 3.5-fold higher, 4-fold higher, 4.5-fold higher, 5-fold higher, 5.5-fold higher, 6-fold higher, 6.5-fold higher, 7-fold higher, 7.5-fold higher, 8-fold higher, 8.5-fold higher, 9-fold higher, 9.5-fold higher, 10-fold higher or more) relative to a reference number. + Cells (e.g., MKI67 + T cells) is about 1.1-fold to about 5-fold higher (e.g., about 1.2-fold to about 2-fold higher, about 1.5-fold to about 3-fold higher, about 2.5-fold to about 4-fold higher, or about 4-fold to about 5-fold higher) relative to a reference number. In some aspects, MKI67 + Cells (e.g., MKI67 + T cells) relative to a reference number by about 2-fold to about 10-fold (e.g., about 2-fold to about 4-fold, about 3-fold to about 5-fold, about 5-fold to about 7-fold, about 6-fold to about 8-fold, or about 7-fold to about 10-fold). In some aspects, MKI67 + Cells (e.g., MKI67 +T cells) is about 5-fold to about 10-fold higher (e.g., about 5-fold to about 6-fold higher, about 6-fold to about 7-fold higher, about 7-fold to about 8-fold higher, about 8-fold to about 9-fold higher, or about 9-fold to about 10-fold higher) relative to a reference number.

[0314] In some aspects, MKI67 in a sample + Cells (e.g., MKI67 + The number of T cells) is detected by, for example, FC, FACS, Western blot, ELISA, MS, IF, IP, radioimmunoassay, dot blot, HPLC, surface plasmon resonance, spectroscopy or IHC. Any immune-based technique may include the use of MKI67 antibodies, such as monoclonal Ki-67 antibodies or MIB-1 antibodies.

[0315] In some aspects, MKI67 + MKI67 + T cells and / or Gzb + T cells.

[0316] In some aspects, the method can further include administering a bispecific antibody (eg, a bispecific anti-FcRH5 / anti-CD3 antibody described herein) to the subject. In some examples, the bispecific antibody is sivostatin.

[0317] In some aspects, if the amount of MKI67 in a biological sample is greater than or equal to a reference amount, + Cells (e.g., MKI67 + In other aspects, if the number of MKI67 in the biological sample is increased relative to the reference number, the subject is responding to the treatment and the treatment is maintained. + Cells (e.g., MKI67 + If the number of T cells) is the same or decreases, the subject is not responding to the treatment and the treatment is adjusted or stopped. In some aspects, the reference number is MKI67 determined in a population of individuals with MM. + Cells (e.g., MKI67 + T cells).

[0318] C. Treatment methods

[0319] The present invention provides a method for treating a subject with cancer (e.g., MM) with a bispecific antibody. The subject may have an elevated level of a T cell proliferation marker (e.g., MKI67). Treatment may include administering a bispecific antibody (e.g., a bispecific anti-FcRH5 / anti-CD3 antibody) to the subject with a dosing regimen described herein (e.g., a single-step ascending dosing regimen or a double-step ascending dosing regimen).

[0320] In some aspects, the method includes a step of determining the level of a T cell proliferation marker (e.g., MKI67) in a biological sample (e.g., blood, serum, or plasma) derived from a subject. The biological sample can be obtained from a subject (e.g., a human) with a cancer (e.g., MM) being treated with a bispecific antibody (e.g., a bispecific anti-FcRH5 / anti-CD3 antibody as described herein). In addition, the biological sample can be obtained from the subject at a time point after the bispecific antibody is administered. An exemplary time point after the administration of the bispecific antibody is 1 day or more (e.g., 2 days, 3 days, 4 days, 5 days, 6 days, 7 days, 8 days, 9 days, 10 days, 11 days, 12 days, 13 days, 14 days, 15 days, 16 days, 17 days, 18 days, 19 days, 20 days, 21 days, 22 days, 23 days, 24 days, 25 days, 26 days, 27 days, 28 days, 29 days, 30 days, 31 days or longer) after the bispecific antibody is administered.

[0321] In some aspects, the method further comprises comparing the level of a T cell proliferation marker (e.g., MKI67) in a cell (e.g., a T cell) to a reference level, wherein an increase in the level of the T cell proliferation marker in the biological sample relative to the reference level identifies the subject as a subject responsive to the bispecific anti-FcRH5 / anti-CD3 antibody.

[0322] In some aspects, provided herein is a method of treating a subject having cancer (e.g., MM) with a bispecific antibody that binds to FcRH5 and CD3, the method comprising administering the bispecific antibody to the subject, wherein the subject has previously been monitored according to any of the monitoring methods disclosed herein.

[0323] In some aspects, provided herein is a method of treating a subject having cancer (e.g., MM) with a bispecific antibody that binds to FcRH5 and CD3, the method comprising administering the bispecific antibody to the subject, wherein the subject has been previously assessed according to any of the assessment methods disclosed herein.

[0324] In some aspects, provided herein is a method for treating a subject having cancer (e.g., MM) with a bispecific antibody that binds to FcRH5 and CD3, the method comprising: (a) determining the level of a T cell proliferation marker in a biological sample obtained from the subject at a time point after administration of the bispecific antibody; (b) comparing the level of the T cell proliferation marker in the biological sample to a reference level, wherein if the level of the T cell proliferation marker in the biological sample is increased relative to the reference level, the subject is identified as a subject responsive to the bispecific antibody; and (c) if the level of the T cell proliferation marker is increased relative to the reference level, continuing to administer the bispecific antibody to the subject.

[0325] In some aspects, a bispecific antibody that binds to FcRH5 and CD3 is provided herein for use in the treatment of a subject with MM, the treatment comprising: (a) determining the level of a T cell proliferation marker in a biological sample obtained from a subject at a time point after administration of the bispecific antibody; (b) comparing the level of the T cell proliferation marker in the biological sample with a reference level, wherein the level of the T cell proliferation marker in the biological sample increases relative to the reference level, then the subject is identified as a subject who responds to the bispecific antibody; and (c) if the level of the T cell proliferation marker increases relative to the reference level, then the bispecific antibody is continued to be administered to the subject. Any suitable reference level (e.g., baseline level) can be used. In some aspects, the reference level is the level (e.g., mRNA or protein level) of a T cell proliferation marker (e.g., MKI67) determined in a biological sample obtained from a subject before administering the bispecific antibody to the subject. In some aspects, the biological sample is obtained from the subject at least 30 seconds (e.g., at least 1 minute, at least 2 minutes, at least 3 minutes, at least 4 minutes, at least 5 minutes, at least 10 minutes, at least 15 minutes, at least 30 minutes, at least 1 hour, at least 2 hours, at least 5 hours, at least 10 hours, at least 15 hours, at least 20 hours, or at least 24 hours) prior to administering the bispecific antibody to the subject. In some aspects, the biological sample is obtained from the subject at least 1 day (e.g., at least 2 days, at least 3 days, at least 4 days, at least 5 days, at least 6 days, at least 7 days, at least 8 days, at least 9 days, at least 10 days, at least 11 days, at least 12 days, at least 13 days, at least 14 days, at least 15 days, at least 16 days, at least 17 days, at least 18 days, at least 19 days, at least 20 days, at least 21 days, at least 22 days, at least 23 days, at least 24 days, at least 25 days, at least 26 days, at least 27 days, at least 28 days, at least 29 days, at least 30 days, at least 31 days or more) before the bispecific antibody is administered to the subject. In some aspects, the biological sample is obtained from the subject at least 1 week (e.g., at least 2 weeks, at least 3 weeks, at least 4 weeks, at least 5 weeks or more) before the bispecific antibody is administered to the subject.

[0326] In some aspects, the reference level is the median protein level of MKI67 determined in a population of individuals with MM. In some aspects, the reference level is the median mRNA level of MKI67 determined in a population of individuals with MM. In some embodiments, the reference level is less than 100% (e.g., 99%, 98%, 97%, 96%, 95%, 94%, 93%, 92%, 91%, 90%, 89%, 88%, 87%, 86%, 85%, 84%, 83%, 82%, 81%, 80%, 79%, 78%, 77%, 76%, 75%, 74%, 73%, 72%, 71%, 70%, 69%, 68%, 67%, 66%, 65%, 64%, 63%, 62%, 61%, 60%, 65%, 66%, 67%, 68%, 69%, 69%, 69% , 61% , 62% , 63% , 64% , 65% , 66% , 67% , 68% , 69% , 69% , 69% , 68% , 69% , 68% , 68% , 69% , 69% , 69% , 68 ... %, 9%, 58%, 57%, 56%, 55%, 54%, 53%, 52%, 51%, 50%, 49%, 48%, 47%, 46%, 45%, 44%, 43%, 42%, 41%, 40%, 39%, 38%, 37%, 36%, 35%, 34%, 33%, 32%, 31%, 30%, 29%, 28%, 27%, 26%, 25%, 24%, 23%, 22%, 21%, 20%, 19%, 18%, 17%, 16%, 15%, 14%, 13%, 12%, 11%, 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1% or less). In some aspects, the reference level is about 50% to about 99% (e.g., about 55% to about 75%, about 60% to about 80%, about 65% to about 85%, about 75% to about 85%, about 85% to about 95%, or about 90% to about 99%) of the level of a T cell proliferation marker (e.g., MKI67) determined in a biological sample obtained from a subject prior to administration of the bispecific antibody. In some aspects, the reference level is about 1% to about 50% (e.g., about 1% to about 20%, about 5% to about 25%, about 10% to about 30%, about 20% to about 40%, about 25% to about 45%, or about 45% to about 50%) of the level of a T cell proliferation marker (e.g., MKI67) determined in a biological sample obtained from a subject prior to administration of the bispecific antibody. In some aspects, the reference level is about 0.01% to about 1% (e.g., about 0.05% to about 0.01%, about 0.01% to about 0.5%, or about .5% to about 1%) of the level of a T cell proliferation marker (e.g., MKI67) determined in a biological sample obtained from a subject prior to administration of the bispecific antibody.

[0327] In some aspects, the level of a T cell proliferation marker (e.g., MKI67) is greater than 100% of a reference level (e.g., 101%, 105%, 110%, 120%, 150%, 200%, 250%, 300% or greater). In some aspects, the level of a T cell proliferation marker (e.g., MKI67) is between about 101% and about 1000% of a reference level (e.g., about 101% to about 500%, about 200% to about 400%, about 300% to about 600%, about 400% to about 700%, about 500% to about 800%, about 600% to about 900%, or about 700% to about 1000%). In some aspects, the level of a T cell proliferation marker (e.g., MKI67) is between about 101% and about 500% of a reference level (e.g., about 101% to about 500%, about 101% to about 400%, about 101% to about 300%, or about 101% to about 200%).

[0328] In some aspects, the level of a T cell proliferation marker (e.g., MKI67) is greater than 1-fold higher relative to a reference level (e.g., 1.1-fold higher, 1.2-fold higher, 1.3-fold higher, 1.4-fold higher, 1.5-fold higher, 1.6-fold higher, 1.7-fold higher, 1.8-fold higher, 1.9-fold higher, 2-fold higher, 2.5-fold higher, 3-fold higher, 3.5-fold higher, 4-fold higher, 4.5-fold higher, 5-fold higher, 5.5-fold higher, 6-fold higher, 6.5-fold higher, 7-fold higher, 7.5-fold higher, 8-fold higher, 8.5-fold higher, 9-fold higher, 9.5-fold higher, 10-fold higher, or more). In some aspects, the level of a T cell proliferation marker (e.g., MKI67) is about 1.1 times to about 5 times higher relative to a reference level (e.g., about 1.2 times to about 2 times higher, about 1.5 times to about 3 times higher, about 2.5 times to about 4 times higher, or about 4 times to about 5 times higher). In some aspects, the level of a T cell proliferation marker (e.g., MKI67) is about 2 times to about 10 times higher relative to a reference level (e.g., about 2 times to about 4 times higher, about 3 times to about 5 times higher, about 5 times to about 7 times higher, about 6 times to about 8 times higher, or about 7 times to about 10 times higher). In some aspects, the level of a T cell proliferation marker (e.g., MKI67) is about 5 times to about 10 times higher relative to a reference level (e.g., about 5 times to about 6 times higher, about 6 times to about 7 times higher, about 7 times to about 8 times higher, about 8 times to about 9 times higher, or about 9 times to about 10 times higher).

[0329] In some aspects, the method can further include administering a bispecific antibody (eg, a bispecific anti-FcRH5 / anti-CD3 antibody described herein) to the subject. In some examples, the bispecific antibody is sivostatin.

[0330] In some aspects, the T cell proliferation marker (e.g., MKI67) is a protein level. Any suitable laboratory technique for determining protein levels in a sample can be used, including but not limited to FC, FACS, Western blot, ELISA, MS, IF, IP, radioimmunoassay, dot blot, HPLC, surface plasmon resonance, spectroscopy, and IHC. Any immune-based technique may include the use of an MKI67 antibody, such as a monoclonal Ki-67 antibody or a MIB-1 antibody.

[0331] In some aspects, the T cell proliferation marker (e.g., MKI67) is mRNA level. Any suitable laboratory technique for determining protein expression levels in a sample can be used, including but not limited to PCR, RT-PCR, qPCR, RT-qPCR, microarray analysis, Northern blot, technology, SAGE and RNA sequencing.

[0332] In some aspects, a T cell proliferation marker (eg, MKI67) is detected in a T cell in a biological sample. The T cell may be MKI67 + T cells and / or granzyme B (Gzb) positive (Gzb + )T cells.

[0333] In some aspects, the invention provides methods of treating a subject having cancer (eg, MM) with a bispecific antibody. The subject may have elevated MKI67 + Cells (e.g., MKI67 + The treatment may include administering a bispecific antibody (eg, a bispecific anti-FcRH5 / anti-CD3 antibody) to the subject at a dosing regimen described herein (eg, a single-step ascending dosing regimen or a double-step ascending dosing regimen).

[0334] In some aspects, the method comprises determining the expression of MKI67 in a biological sample (eg, blood, serum, or plasma) derived from the subject. + Cells (e.g., MKI67 +The biological sample can be obtained from a subject (e.g., a human) with cancer (e.g., MM) being treated with a bispecific antibody (e.g., a bispecific anti-FcRH5 / anti-CD3 antibody described herein). In addition, the biological sample can be obtained from the subject at a time point after administration of the bispecific antibody. Exemplary time points after administration of the bispecific antibody are 1 or more days (e.g., 2 days, 3 days, 4 days, 5 days, 6 days, 7 days, 8 days, 9 days, 10 days, 11 days, 12 days, 13 days, 14 days, 15 days, 16 days, 17 days, 18 days, 19 days, 20 days, 21 days, 22 days, 23 days, 24 days, 25 days, 26 days, 27 days, 28 days, 29 days, 30 days, 31 days or longer) after administration of the bispecific antibody.

[0335] In some aspects, the method further comprises converting MKI67 + Cells (e.g., MKI67 + T cells) is compared to a reference number, wherein the MKI67 in the biological sample is greater than the reference number. + If the number of cells (e.g., T cells) increases, the subject is identified as a subject that is responsive to the bispecific antibody.

[0336] In some aspects, provided herein is a method for treating a subject having cancer (e.g., MM) with a bispecific antibody that binds to FcRH5 and CD3, the method comprising: (a) determining whether a biological sample obtained from the subject at a time point after administration of the bispecific antibody is positive for the proliferation marker Ki-67 (MKI67 + ) the number of T cells; (b) the MKI67 in biological samples + The number of T cells is compared to a reference number, where the MKI67 in the biological sample is higher relative to the reference number. + If the number of T cells increases, the subject is identified as a subject that responds to the bispecific antibody; and (c) if the number of MKI67 in the biological sample of the subject is increased relative to the reference number, + If the number of T cells increases, then the bispecific antibody continues to be administered to the subject.

[0337] In some aspects, provided herein is a bispecific antibody that binds to FcRH5 and CD3 for use in treating a subject with MM, the treatment comprising: (a) determining whether a biological sample obtained from the subject at a time point after administration of the bispecific antibody is positive for the proliferation marker Ki-67 (MKI67 + ) the number of T cells; (b) the MKI67 in biological samples +The number of T cells is compared to a reference number, where the MKI67 in the biological sample is higher relative to the reference number. + If the number of T cells increases, the subject is identified as a subject that responds to the bispecific antibody; (c) if the MKI67 in the biological sample of the subject is increased relative to the reference number, + If the number of T cells increases, then the bispecific antibody continues to be administered to the subject.

[0338] Any suitable reference amount (eg, a baseline level) can be used. In some aspects, the reference amount is MKI67 determined in a biological sample obtained from a subject prior to administering the bispecific antibody to the subject. + Cells (e.g., MKI67 + In some aspects, the biological sample is obtained from the subject at least 30 seconds (e.g., at least 1 minute, at least 2 minutes, at least 3 minutes, at least 4 minutes, at least 5 minutes, at least 10 minutes, at least 15 minutes, at least 30 minutes, at least 1 hour, at least 2 hours, at least 5 hours, at least 10 hours, at least 15 hours, at least 20 hours, or at least 24 hours) prior to administering the bispecific antibody to the subject. In some aspects, the biological sample is obtained from the subject at least 1 day (e.g., at least 2 days, at least 3 days, at least 4 days, at least 5 days, at least 6 days, at least 7 days, at least 8 days, at least 9 days, at least 10 days, at least 11 days, at least 12 days, at least 13 days, at least 14 days, at least 15 days, at least 16 days, at least 17 days, at least 18 days, at least 19 days, at least 20 days, at least 21 days, at least 22 days, at least 23 days, at least 24 days, at least 25 days, at least 26 days, at least 27 days, at least 28 days, at least 29 days, at least 30 days, at least 31 days or more) before the bispecific antibody is administered to the subject. In some aspects, the biological sample is obtained from the subject at least 1 week (e.g., at least 2 weeks, at least 3 weeks, at least 4 weeks, at least 5 weeks or more) before the bispecific antibody is administered to the subject.

[0339] In some aspects, the reference amount is MKI67 determined in a population of individuals with MM. + Cells (e.g., MKI67 + In some embodiments, the reference number is less than the median number of MKI67 cells (e.g., MKI67 T cells) measured in subjects being treated with the bispecific antibody and / or being assessed or monitored after treatment. +100% (e.g., 99%, 98%, 97%, 96%, 95%, 94%, 93%, 92%, 91%, 90%, 89%, 88%, 87%, 86%, 85%, 84%, 83%, 82%, 81%, 80%, 79%, 78%, 77%, 76%, 75%, 74%, 73%, 72%, 71%, 70%, 69%, 68%, 67%, 66%, 65%, 64%, 63%, 62%, 61%, 60%, 59%, 58%, 57%, 56%, 55%, 54%, 53%, 54%, 55%, 56%, 57%, 58%, 59 ... %, 52%, 51%, 50%, 49%, 48%, 47%, 46%, 45%, 44%, 43%, 42%, 41%, 40%, 39%, 38%, 37%, 36%, 35%, 34%, 33%, 32%, 31%, 30%, 29%, 28%, 27%, 26%, 25%, 24%, 23%, 22%, 21%, 20%, 19%, 18%, 17%, 16%, 15%, 14%, 13%, 12%, 11%, 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1% or less). In some aspects, the reference amount is MKI67 determined in a biological sample obtained from the subject prior to administration of the bispecific antibody. + Cells (e.g., MKI67 + T cells) (e.g., about 55% to about 75%, about 60% to about 80%, about 65% to about 85%, about 75% to about 85%, about 85% to about 95%, or about 90% to about 99%). In some aspects, the reference amount is the MKI67 T cell population determined in a biological sample obtained from the subject prior to administration of the bispecific antibody. + Cells (e.g., MKI67 + T cells) (e.g., about 1% to about 20%, about 5% to about 25%, about 10% to about 30%, about 20% to about 40%, about 25% to about 45%, or about 45% to about 50%). In some aspects, the reference amount is the MKI67 T cell population determined in a biological sample obtained from the subject prior to administration of the bispecific antibody. + Cells (e.g., MKI67 + T cells) (eg, about 0.05% to about 0.01%, about 0.01% to about 0.5%, or about 0.5% to about 1%).

[0340] In some aspects, MKI67 + Cells (e.g., MKI67 +T cells) is greater than 100% (e.g., 101%, 105%, 110%, 120%, 150%, 200%, 250%, 300% or more) of the reference number. In some aspects, MKI67 + Cells (e.g., MKI67 + T cells) is between about 101% and about 1000% of a reference number (e.g., about 101% to about 500%, about 200% to about 400%, about 300% to about 600%, about 400% to about 700%, about 500% to about 800%, about 600% to about 900%, or about 700% to about 1000%). In some aspects, MKI67 + Cells (e.g., MKI67 + T cells) is between about 101% and about 500% of a reference number (e.g., about 101% to about 500%, about 101% to about 400%, about 101% to about 300%, or about 101% to about 200%).

[0341] In some aspects, MKI67 + Cells (e.g., MKI67 + In some aspects, the number of MKI67 T cells is greater than 1-fold higher (e.g., 1.1-fold higher, 1.2-fold higher, 1.3-fold higher, 1.4-fold higher, 1.5-fold higher, 1.6-fold higher, 1.7-fold higher, 1.8-fold higher, 1.9-fold higher, 2-fold higher, 2.5-fold higher, 3-fold higher, 3.5-fold higher, 4-fold higher, 4.5-fold higher, 5-fold higher, 5.5-fold higher, 6-fold higher, 6.5-fold higher, 7-fold higher, 7.5-fold higher, 8-fold higher, 8.5-fold higher, 9-fold higher, 9.5-fold higher, 10-fold higher or more) relative to a reference number. + Cells (e.g., MKI67 + T cells) is about 1.1-fold to about 5-fold higher (e.g., about 1.2-fold to about 2-fold higher, about 1.5-fold to about 3-fold higher, about 2.5-fold to about 4-fold higher, or about 4-fold to about 5-fold higher) relative to a reference number. In some aspects, MKI67 + Cells (e.g., MKI67 + T cells) relative to a reference number by about 2-fold to about 10-fold (e.g., about 2-fold to about 4-fold, about 3-fold to about 5-fold, about 5-fold to about 7-fold, about 6-fold to about 8-fold, or about 7-fold to about 10-fold). In some aspects, MKI67 + Cells (e.g., MKI67 +T cells) is about 5-fold to about 10-fold higher (e.g., about 5-fold to about 6-fold higher, about 6-fold to about 7-fold higher, about 7-fold to about 8-fold higher, about 8-fold to about 9-fold higher, or about 9-fold to about 10-fold higher) relative to a reference number.

[0342] In some aspects, the method can further include administering a bispecific antibody (eg, a bispecific anti-FcRH5 / anti-CD3 antibody described herein) to the subject. In some examples, the bispecific antibody is sivostatin.

[0343] In some aspects, the number of MKI67+ cells (e.g., MKI67+ T cells) in a sample is detected by, for example, FC, FACS, Western blot, ELISA, MS, IF, IP, radioimmunoassay, dot blot, HPLC, surface plasmon resonance, spectroscopy or IHC. Any immune-based technique may include the use of MKI67 antibodies, such as monoclonal Ki-67 antibodies or MIB-1 antibodies.

[0344] In some aspects, a T cell proliferation marker (eg, MKI67) is detected in a T cell in a biological sample. The T cell may be MKI67 + T cells and / or Gzb + T cells.

[0345] D. Dosage regimen

[0346] In some aspects, the invention provides methods of treating a subject with cancer (e.g., MM) with an administration regimen having elevated levels of a T cell proliferation marker (e.g., MKI67) and / or increased MKI67 + The number of cells. Any suitable dosing regimen can be used. In some instances, the dosing regimen is the dosing regimen described in International Patent Application No. PCT / US2022 / 023161 or PCT / US2022 / 028770, each of which is incorporated herein by reference in its entirety. In some instances, the dosing regimen is the dosing regimen described in U.S. Patent Application No. 63 / 368,352 or 63 / 368,811, each of which is incorporated herein by reference in its entirety. In some aspects, the present invention provides a method for treating a subject with cancer (e.g., MM) with the following single-step incremental or double-step incremental dosing regimen, the subject having an elevated level of a T cell proliferation marker (e.g., MKI67) and / or increased MKI67 + The number of cells.

[0347] Single-step dosing regimen

[0348] In some aspects, the invention provides methods of treating a subject having cancer (e.g., multiple myeloma (MM)) who has elevated levels of a T cell proliferation marker (e.g., MKI67) and / or increased MKI67 + The method comprises administering to the subject a bispecific antibody that binds to FcRH5 and CD3 (eg, sivostatin) in a single-step ascending dosing schedule.

[0349] In some aspects, the invention provides a method of treating a subject having cancer (e.g., multiple myeloma (MM)) who has elevated levels of a T cell proliferation marker (e.g., MKI67) and / or increased MKI67 + The method comprises administering to the subject a bispecific antibody that binds to FcRH5 and CD3 (e.g., sivostomumab) in a dosing regimen that includes at least a first dosing cycle, wherein the first dosing cycle includes a first dose (C1D1) and a second dose (C1D2) of the bispecific antibody, wherein C1D1 is between about 0.05 mg and about 180 mg (e.g., between about 0.1 mg and about 160 mg, between about 0.5 mg and about 140 mg, between about 1 mg and about 120 mg, between about 1.5 mg and about 100 mg, between about 2.0 mg and about 80 mg, between about 2.5 mg and about 50 mg, between about 3. 0 mg to about 25 mg, between about 3.0 mg to about 15 mg, between about 3.0 mg to about 10 mg, or between about 3.0 mg to about 5 mg), and the C1D2 is between about 0.15 mg to about 1000 mg (e.g., between about 0.5 mg to about 800 mg, between about 1 mg to about 700 mg, between about 5 mg to about 500 mg, between about 10 mg to about 400 mg, between about 25 mg to about 300 mg, between about 40 mg to about 200 mg, between about 50 mg to about 100 mg, between about 75 mg to about 100 mg, or between about 85 mg to about 100 mg).

[0350] In some aspects, the invention provides a method of treating a subject having cancer (e.g., MM) who has elevated levels of a T cell proliferation marker (e.g., MKI67) and / or increased MKI67 +The method comprises administering to a subject a bispecific antibody that binds to FcRH5 and CD3 (e.g., sivostomumab) in a dosing regimen that includes at least a first dosing cycle and a second dosing cycle, wherein (a) the first dosing cycle includes a first dose (C1D1; cycle 1, dose 1) and a second dose (C1D2; cycle 1, dose 2) of the bispecific antibody, wherein C1D1 is less than C1D2, and wherein C1D1 is between about 0.05 mg and about 180 mg (e.g., between about 0.1 mg and about The amount of C1D2 is between about 0.15 mg and about 1000 mg (e.g., between about 0.5 mg and about 140 mg, between about 1 mg and about 120 mg, between about 1.5 mg and about 100 mg, between about 2.0 mg and about 80 mg, between about 2.5 mg and about 50 mg, between about 3.0 mg and about 25 mg, between about 3.0 mg and about 15 mg, between about 3.0 mg and about 10 mg, or between about 3.0 mg and about 5 mg), and the amount of C1D2 is between about 0.15 mg and about 1000 mg (e.g., between about 0.5 mg and about 140 mg, between about 1 mg and about 120 mg, between about 1.5 mg and about 100 mg, between about 2.0 mg and about 80 mg, between about 2.5 mg and about 50 mg, between about 3.0 mg and about 25 mg, between about 3.0 mg and about 15 mg, between about 3.0 mg and about 10 mg, or between about 3.0 mg and about 5 mg). between about 0.5 mg to about 800 mg, between about 1 mg to about 700 mg, between about 5 mg to about 500 mg, between about 10 mg to about 400 mg, between about 25 mg to about 300 mg, between about 40 mg to about 200 mg, between about 50 mg to about 100 mg, between about 75 mg to about 100 mg, or between about 85 mg to about 100 mg); and (b) the second dosing cycle comprises a single dose of the bispecific antibody (C2D1; Cycle 2, Dose 1), wherein C2D1 is equal to or greater than C1D2 and is between about 0.15 mg and about 1000 mg (e.g., between about 0.5 mg and about 800 mg, between about 1 mg and about 700 mg, between about 5 mg and about 500 mg, between about 10 mg and about 400 mg, between about 25 mg and about 300 mg, between about 40 mg and about 200 mg, between about 50 mg and about 100 mg, between about 75 mg and about 100 mg, or between about 85 mg and about 100 mg).

[0351] In some aspects, (a) C1D1 is about 0.5 mg to about 19.9 mg (e.g., about 1 mg to about 18 mg, about 2 mg to about 15 mg, about 3 mg to about 10 mg, about 3.3 mg to about 6 mg, or about 3.4 mg to about 4 mg, for example, about 3 mg, 3.2 mg, 3.4 mg, 3.6 mg, 3.8 mg, 4 mg, 4.2 mg, 4.4 mg, 4.6 mg, 4.8 mg, 5 mg, 5.2 mg, 5.6 mg, 5.8 mg, 6 mg, 6.2 mg, 6.4 mg, 6.6 mg, 6.8 mg, 7 mg, 7.2mg, 7.4mg, 7.6mg, 7.8mg, 8mg, 8.2mg, 8.4mg, 8.6mg, 8.8mg, 9mg, 9.2mg, 9.4mg, 9.6mg, 9.8mg, 10mg, 10.2mg, 10.4 mg, 10.6mg, 10.8mg, 11mg, 11.2mg, 11.4mg, 11.6mg, 11.8mg, 12mg, 12.2mg, 12.4mg, 12.6mg, 12.8mg, 13mg, 13.2mg, 13.4m 6 mg, 18.8 mg, 19 mg, 19.2 mg, 19.4 mg, 19.6 mg or 19.8 mg), and (b) C1D2 is from about 20 mg to about 600 mg (e.g., about 30 to 500 mg, 40 to 400 mg, 60 to 350 mg, 80 to 300 mg, 100 to 200 mg, or 140 to 180 mg, for example, about 20, 40, 60, 80, 100, 120, 140, 160, 180, 200, 220, 240, 260, 280, 300, 320, 340, 360, 380, 400, 420, 440, 460, 480, 500, 520, 540, 560, 580, or 600 mg).

[0352] In some aspects, C1D1 is about 1.2 mg to about 10.8 mg and C1D2 is about 80 mg to about 300 mg. In some aspects, C1D1 is about 3.6 mg and C1D2 is about 198 mg. In some aspects, C1D1 is 1.2 mg to 10.8 mg and C1D2 is 80 mg to 300 mg. In some aspects, C1D1 is 3.6 mg and C1D2 is 198 mg.

[0353] In some cases, the above methods may include a first dosing cycle of one week or 7 days. In some cases, the method may include administering only C1D1 to the subject on or about day 1 of the first dosing cycle.

[0354] In some cases, the above methods may include a first dosing cycle of two weeks or 14 days. In some cases, the method may include administering C1D1 and C1D2 to the subject on or about days 1 and 8 of the first dosing cycle, respectively.

[0355] In some cases, the above methods may include a first dosing cycle of three weeks or 21 days. In some cases, the method may include administering C1D1 and C1D2 to the subject on or about days 1 and 8 of the first dosing cycle, respectively.

[0356] In some cases, the above methods may include a first dosing cycle of four weeks or 28 days. In some cases, the method may include administering C1D1 and C1D2 to the subject on or about days 1 and 8 of the first dosing cycle, respectively.

[0357] In some embodiments, the subject has an elevated level of a T cell proliferation marker relative to a reference level. In some embodiments, the subject has an elevated level of a MKI67 relative to a reference level. + Cells (e.g., MKI67 + The number of T cells).

[0358] Two-step dosing regimen

[0359] In other aspects, the invention provides methods of treating a subject having cancer (e.g., MM) who has elevated levels of a T cell proliferation marker (e.g., MKI67) and / or increased MKI67 + The method comprises administering to the subject a bispecific antibody that binds to FcRH5 and CD3 (eg, sivostatin) in a two-step ascending dosing schedule.

[0360] In some aspects, the disclosure features a method of treating a subject having cancer (e.g., MM) who has elevated levels of a T cell proliferation marker (e.g., MKI67) and / or increased MKI67 +The method comprises administering a bispecific antibody that binds to FcRH5 and CD3 (e.g., sivostatin) to the subject at a dosing regimen that includes at least a first dosing cycle, wherein the first dosing cycle includes a first dose (C1D1), a second dose (C1D2), and a third dose (C1D3) of the bispecific antibody, wherein C1D1 is between about 0.2 mg and about 0.4 mg (e.g., about 0.20 mg, 0.21 mg, 0.22 mg, 0.23 mg, 0.24 mg, 0.25 mg, 0.26 mg, 0.27 mg, 0.28 mg, 0.29 mg, 0.30 mg, 0.31 mg, 0.32 mg, 0.33 mg, 0.34 mg, 0.35 mg, 0.36 mg, 0.37 mg, 0.38 mg, 0.39 mg, or 0.40 mg); C1D2 is greater than C1D1, and C1D3 is greater than C1D2. In some aspects, C1D1 is about 0.3 mg.

[0361] In some aspects, C1D1 is between 0.2 mg and 0.4 mg (e.g., 0.20 mg, 0.21 mg, 0.22 mg, 0.23 mg, 0.24 mg, 0.25 mg, 0.26 mg, 0.27 mg, 0.28 mg, 0.29 mg, 0.30 mg, 0.31 mg, 0.32 mg, 0.33 mg, 0.34 mg, 0.35 mg, 0.36 mg, 0.37 mg, 0.38 mg, 0.39 mg, or 0.40 mg). In some aspects, C1D1 is 0.3 mg.

[0362] In some aspects, the present disclosure provides a method of treating a subject having cancer (e.g., MM) who has elevated levels of a T cell proliferation marker (e.g., MKI67) and / or increased MKI67 + The method comprises administering to the subject a bispecific antibody that binds to FcRH5 and CD3 (e.g., sivostatin) at a dosing regimen that includes at least a first dosing cycle, wherein the first dosing cycle includes a first dose (C1D1), a second dose (C1D2), and a third dose (C1D3) of the bispecific antibody, wherein C1D1 is between about 0.01 mg and about 2.9 mg, C1D2 is between about 3 mg and about 19.9 mg, and C1D3 is between about 20 mg and about 600 mg.

[0363] In some aspects, the invention provides a method of treating a subject having cancer (e.g., MM) who has elevated levels of a T cell proliferation marker (e.g., MKI67) and / or increased MKI67 +The method comprises administering to the subject a bispecific antibody that binds to FcRH5 and CD3 (e.g., sivostatin) in a dosing regimen that includes at least a first dosing cycle and a second dosing cycle, wherein (a) the first dosing cycle includes a first dose (C1D1), a second dose (C1D2), and a third dose (C1D3) of the bispecific antibody, wherein C1D1 and C1D2 are each less than C1D3, and wherein C1D1 is between about 0.01 mg and about 2.9 mg, C1D2 is between about 3 mg and about 19.9 mg, and C1D3 is between about 20 mg and about 600 mg; and (b) the second dosing cycle includes a single dose (C2D1) of the bispecific antibody, wherein C2D1 is equal to or greater than C1D3 and is between about 20 mg and about 600 mg.

[0364] In some aspects, C1D1 is between about 0.05 mg to about 2.5 mg, about 0.1 mg to about 2 mg, about 0.2 mg to about 1 mg, or about 0.2 mg to about 0.4 mg (e.g., about 0.01 mg, 0.05 mg, 0.1 mg, 0.2 mg, 0.3 mg, 0.4 mg, 0.5 mg, 0.6 mg, 0.7 mg, 0.9 mg, 1 mg, 1.1 mg, 1.2 mg, 1.3 mg, 1.4 mg, 1.5 mg, 1.6 mg, 1.7 mg, 1.8 mg, 1.9 mg, 2 mg, 2.1 mg, 2.2 mg, 2.3 mg, 2.4 mg, 2.5 mg, 2.6 mg, 2.7 mg, 2.8 mg, or 2.9 mg). In some aspects, C1D1 is about 0.3 mg.

[0365] In some aspects, C1D1 is between 0.05 mg and 2.5 mg, 0.1 mg and 2 mg, 0.2 mg and 1 mg, or 0.2 mg and 0.4 mg (e.g., 0.01 mg, 0.05 mg, 0.1 mg, 0.2 mg, 0.3 mg, 0.4 mg, 0.5 mg, 0.6 mg, 0.7 mg, 0.9 mg, 1 mg, 1.1 mg, 1.2 mg, 1.3 mg, 1.4 mg, 1.5 mg, 1.6 mg, 1.7 mg, 1.8 mg, 1.9 mg, 2 mg, 2.1 mg, 2.2 mg, 2.3 mg, 2.4 mg, 2.5 mg, 2.6 mg, 2.7 mg, 2.8 mg, or 2.9 mg). In some aspects, C1D1 is 0.3 mg.

[0366] In some aspects, C1D2 is between about 3 mg to about 19.9 mg (e.g., between about 3 mg to about 18 mg, between about 3.1 mg to about 15 mg, between about 3.2 mg to about 10 mg, between about 3.3 mg to about 6 mg, or between about 3.4 mg to about 4 mg, for example, about 3 mg, 3.2 mg, 3.4 mg, 3.6 mg, 3.8 mg, 4 mg, 4.2 mg, 4.4 mg, 4.6 mg, 4.8 mg, 5 mg, 5.2 mg, 5.6 mg, 5.8 mg, 6 mg, 6.2 mg, 6.4 mg, 6.6 mg, 6.8 mg, 7 mg, 7.2 mg, 7.4 mg, 7.6 mg, 7.8 mg, 8 mg, 8.2 mg, 8.4 mg, 8.6 mg, 8.8 mg, 9 mg, 9.2 mg, 9.4 mg, 9.6 mg, 9.8 mg g, 10mg, 10.2mg, 10.4mg, 10.6mg, 10.8mg, 11mg, 11.2mg, 11.4mg, 11.6mg, 11.8mg, 12mg, 12 .2mg, 12.4mg, 12.6mg, 12.8mg, 13mg, 13.2mg, 13.4mg, 13.6mg, 13.8mg, 14mg, 14.2mg, 14.4 In some aspects, C1D2 is between about 3.2 mg and about 10 mg. In some aspects, C1D2 is about 3.6 mg.

[0367] In some aspects, C1D2 is between 3 mg and 19.9 mg (e.g., between 3 mg and 18 mg, between 3.1 mg and 15 mg, between 3.2 mg and 10 mg, between 3.3 mg and 6 mg, or between 3.4 mg and 4 mg, for example, 3 mg, 3.2 mg, 3.4 mg, 3.6 mg, 3.8 mg, 4 mg, 4.2 mg, 4.4 mg, 4.6 mg, 4.8 mg, 5 mg, 5.2 mg, 5.6 mg, 5.8 mg, 6 mg, 6.2 mg, 6.4 mg, 6.6 mg, 6.8 mg, 7 mg, 7.2 mg, 7.4 mg, 7.6 mg, 7.8 mg, 8 mg, 8.2 mg, 8.4 mg, 8.6 mg, 8.8 mg, 9 mg, 9.2 mg, 9.4 mg, 9.6 mg, 9.8 mg, 10 mg, 10.2mg, 10.4mg, 10.6mg, 10.8mg, 11mg, 11.2mg, 11.4mg, 11.6mg, 11.8mg, 12mg, 12.2mg, 12.4mg, 12.6mg, 12.8mg, 13mg, 13.2mg, 13.4mg, 13.6mg, 13.8mg, 14mg, 14.2mg, 14.4mg, In some aspects, C1D2 is between 3.2 mg and 10 mg. In some aspects, C1D2 is 3.6 mg.

[0368] In some aspects, C1D3 is between about 20 mg to about 600 mg (e.g., between about 30 mg to about 500 mg, about 40 mg to about 400 mg, about 60 mg to about 350 mg, about 80 mg to about 300 mg, about 100 mg to about 200 mg, or about 140 mg to about 180 mg, for example, about 20 mg, 40 mg, 60 mg, 80 mg, 100 mg, 120 mg, 140 mg, 160 mg, 180 mg, 200 mg, 220 mg, 240 mg, 260 mg, 280 mg, 300 mg, 320 mg, 340 mg, 360 mg, 380 mg, 400 mg, 420 mg, 440 mg, 460 mg, 480 mg, 500 mg, 520 mg, 540 mg, 560 mg, 580 mg, or 600 mg). In some aspects, C1D3 is between about 80 mg and about 300 mg. In some aspects, C1D3 is about 160 mg.

[0369] In some aspects, C1D3 is between 20 mg and 600 mg (e.g., between 30 mg and 500 mg, 40 mg and 400 mg, 60 mg and 350 mg, 80 mg and 300 mg, 100 mg and 200 mg, or 140 mg and 180 mg, for example, 20 mg, 40 mg, 60 mg, 80 mg, 100 mg, 120 mg, 140 mg, 160 mg, 180 mg, 200 mg, 220 mg, 240 mg, 260 mg, 280 mg, 300 mg, 320 mg, 340 mg, 360 mg, 380 mg, 400 mg, 420 mg, 440 mg, 460 mg, 480 mg, 500 mg, 520 mg, 540 mg, 560 mg, 580 mg, or 600 mg). In some aspects, C1D3 is between 80 mg and 300 mg. In some aspects, C1D3 is 160 mg.

[0370] In some aspects, the method includes only a single dosing cycle (e.g., a dosing cycle including C1D1, C1D2, and C1D3). In other aspects, the dosing regimen further includes a second dosing cycle that includes at least a single dose (C2D1) of the bispecific antibody. In some aspects, C2D1 is equal to or greater than C1D3 and is between about 20 mg to about 600 mg (e.g., between about 30 mg to about 500 mg, about 40 mg to about 400 mg, about 60 mg to about 350 mg, about 80 mg to about 300 mg, about 100 mg to about 200 mg, or about 140 mg to about 180 mg, for example, about 20 mg, 40 mg, 60 mg, 80 mg, 100 mg, 120 mg, 140 mg, 160 mg, 180 mg, 200 mg, 220 mg, 240 mg, 260 mg, 280 mg, 300 mg, 320 mg, 340 mg, 360 mg, 380 mg, 400 mg, 420 mg, 440 mg, 460 mg, 480 mg, 500 mg, 520 mg, 540 mg, 560 mg, 580 mg, or 600 mg). In some aspects, C2D1 is between about 80 mg and about 300 mg. In some aspects, C2D1 is about 160 mg.

[0371] In some aspects, C2D1 is between 20 mg and 600 mg (e.g., between 30 mg and 500 mg, 40 mg and 400 mg, 60 mg and 350 mg, 80 mg and 300 mg, 100 mg and 200 mg, or 140 mg and 180 mg, for example, 20 mg, 40 mg, 60 mg, 80 mg, 100 mg, 120 mg, 140 mg, 160 mg, 180 mg, 200 mg, 220 mg, 240 mg, 260 mg, 280 mg, 300 mg, 320 mg, 340 mg, 360 mg, 380 mg, 400 mg, 420 mg, 440 mg, 460 mg, 480 mg, 500 mg, 520 mg, 540 mg, 560 mg, 580 mg, or 600 mg). In some aspects, C2D1 is between 80 mg and 300 mg. In some aspects, C2D1 is 160 mg. In some aspects, C2D1 is 159 mg.

[0372] Alternatively, in any of the above embodiments, C1D1 can be between about 0.01 mg and about 60 mg (e.g., between about 0.05 mg and about 50 mg, between about 0.01 mg and about 40 mg, between about 0.1 mg and about 20 mg, between about 0.1 mg and about 10 mg, between about 0.1 mg and about 5 mg, between about 0.1 mg and about 2 mg, between about 0.1 mg and about 1.5 mg, between about 0.1 mg and about 1.2 mg, between about 0.1 mg and about 0.5 mg, or between about 0.2 mg and about 0.4 mg, for example, about 0.3 mg, such as 0.3 mg), C1D2 can be between about 0.05 mg and about 180 mg (e.g., between about 0.1 mg and about 160 mg, between about 0.5 mg and about 140 mg, between about 1 mg and about 120 mg, between about 1.5 mg and about 100 mg, between about 2.0 mg and about 80 mg, between about 2.5 mg and about 50 mg, between about 3.0 mg and about 25 mg, between about 3.0 mg and about 15 mg, between about 3.0 mg and about 10 mg, between about 3.0 mg and about 5 mg, or between about 3.0 mg and about 4.0 mg, e.g., about 3.6 mg, e.g., 3.6 mg), and C1D3 may be between about 0.15 mg and about 1000 mg (e.g., between about 0.5 mg and about 800 mg, between about 1 mg and about 700 mg, between about 5 mg and about 500 mg, between about 10 mg and about 400 mg, between about 25 mg and about 300 mg, between about 40 mg and about 200 mg, between about 50 mg and about 190 mg, between about 140 mg and about 180 mg, or between about 150 mg and about 170 mg, e.g., about 160 mg, e.g., 1 60 mg); and in aspects comprising a second dosing cycle, C2D1 can be between about 0.15 mg to about 1000 mg (e.g., between about 0.5 mg to about 800 mg, between about 1 mg to about 700 mg, between about 5 mg to about 500 mg, between about 10 mg to about 400 mg, between about 25 mg to about 300 mg, between about 40 mg to about 200 mg, between about 50 mg to about 190 mg, between about 140 mg to about 180 mg, or between about 150 mg to about 170 mg, e.g., about 160 mg, e.g., 160 mg).

[0373] In some cases, the length of the first dosing cycle is three weeks or 21 days. In some cases, the method may include administering C1D1, C1D2, and C1D3 to the subject on or around day 1, day 8, and day 15 of the first dosing cycle, respectively.

[0374] In some embodiments, the subject has an elevated level of a T cell proliferation marker relative to a reference level. In some embodiments, the subject has an elevated level of a MKI67 relative to a reference level. + Cells (e.g., MKI67 + The number of T cells).

[0375] Additional dosing cycles

[0376] In some cases, the method may include one or more additional dosing cycles. In some cases, the dosing regimen includes 1 to 17 additional dosing cycles (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, or 17 additional dosing cycles, for example, 1 to 3 additional dosing cycles, 1 to 5 additional dosing cycles, 3 to 8 additional dosing cycles, 5 to 10 additional dosing cycles, 8 to 12 additional dosing cycles, 10 to 15 additional dosing cycles, 12 to 17 additional dosing cycles, or 15 to 17 additional dosing cycles, i.e., the dosing regimen includes one or more additional dosing cycles C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C In some embodiments, the length of each of the one or more additional dosing cycles is 7 days, 14 days, 21 days, or 28 days. In some embodiments, the length of each of the one or more additional dosing cycles is between 5 days and 30 days, for example, between 5 days and 9 days, between 7 days and 11 days, between 9 days and 13 days, between 11 days and 15 days, between 13 days and 17 days, between 15 days and 19 days, between 17 days and 21 days, between 19 days and 23 days, between 21 days and 25 days, between 23 days and 27 days, or between 25 days and 30 days. In some cases, one or more additional dosing cycles In some cases, the length of each of the one or more additional dosing cycles is one week or 7 days. In some cases, the length of each of the one or more additional dosing cycles is two weeks or 14 days. In some cases, the length of each of the one or more additional dosing cycles is three weeks or 21 days. In some cases, the length of each of the one or more additional dosing cycles is four weeks or 28 days. In some cases, each of the one or more additional dosing cycles includes a single dose of the bispecific antibody. In some aspects, the dose of the bispecific antibody in one or more additional dosing cycles is equal to C2D1, for example, between about 20 mg to about 600 mg (e.g., between about 30 mg to about 500 mg, about 40 mg to about 400 mg , about 60 mg to about 350 mg, about 80 mg to about 300 mg, about 100 mg to about 200 mg, or about 140 mg to about 180 mg, for example, about 20 mg, 40 mg, 60 mg, 80 mg, 100 mg, 120 mg, 140 mg, 160 mg, 180 mg, 200 mg, 220 mg, 240 mg, 260 mg, 280 mg, 300 mg, 320 mg, 340 mg, 360 mg, 380 mg, 400 mg, 420 mg, 440 mg, 460 mg, 480 mg, 500 mg, 520 mg, 540 mg, 560 mg, 580 mg or 600 mg).In some aspects, the dose of the bispecific antibody in one or more additional dosing cycles is about 160 mg. In some aspects, the dose of the bispecific antibody in one or more additional dosing cycles is about 198 mg. In some aspects, the dose of the bispecific antibody in one or more additional dosing cycles is equal to C2D1, for example, 20 mg to 600 mg (e.g., 30 mg to 500 mg, 40 mg to 400 mg, 60 mg to 350 mg, 80 mg to 300 mg, 100 mg to 200 mg, or 140 mg to 180 mg, for example, 20 mg, 40 mg, 60 mg, 80 mg, 100 mg, 120 mg, 140 mg, 160 mg, 180 mg, 200 mg, 220 mg, 240 mg, 260 mg, 280 mg, 300 mg, 320 mg, 340 mg, 360 mg, 380 mg, 400 mg, 420 mg, 440 mg, 460, 480 mg, 500 mg, 520 mg, 540 mg, 560 mg, 580 mg, or 600 mg). In some aspects, the dosage of the bispecific antibody in one or more additional dosing cycles is 160 mg. In some aspects, the dosage of the bispecific antibody in one or more additional dosing cycles is 198 mg. In some cases, the method includes administering a single dose of the bispecific antibody to the subject on or about day 1 of the one or more additional dosing cycles.

[0377] In some aspects, the bispecific antibody is administered to the subject every 21 days (Q3W) until disease progression is observed, for up to 18 cycles, or until minimal residual disease (MRD) is observed.

[0378] In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody is administered to a subject as monotherapy.

[0379] In some cases, the bispecific antibody (eg, a bispecific anti-FcRH5 / anti-CD3 antibody) is sivostatin.

[0380] In some embodiments, the subject has an elevated level of a T cell proliferation marker relative to a reference level. In some embodiments, the subject has an elevated level of a MKI67 relative to a reference level. + Cells (e.g., MKI67 + The number of T cells).

[0381] E. Combination therapy

[0382] In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody is administered to a subject in combination therapy. For example, the bispecific anti-FcRH5 / anti-CD3 antibody can be co-administered with one or more additional therapeutic agents.

[0383] i. Tocilizumab and treatment of CRS

[0384] In one embodiment, the additional therapeutic agent is an effective amount of tocilizumab In some cases, a subject has a cytokine release syndrome (CRS) event (for example, a CRS event occurs after treatment with a bispecific antibody (for example, silvostomumab), such as a CRS event occurs after treatment with a bispecific antibody of C1D1, C1D2, C1D3, C2D1 or an additional dose), and the method further includes treating the symptoms of the CRS event (for example, by applying an effective amount of tocilizumab to the subject to treat the CRS event), while suspending treatment with the bispecific antibody. In some aspects, tocilizumab is administered intravenously to the subject in a single dose of about 8mg / kg. In some aspects, the CRS event does not subside or worsen within 24 hours of treating the symptoms of the CRS event, and the method further includes administering one or more additional doses of tocilizumab to the subject to manage the CRS event, for example, administering one or more additional doses of tocilizumab to the subject intravenously at a dosage of about 8mg / kg.

[0385] In some aspects, treating the symptoms of a CRS event further comprises treatment with a high-dose vasopressor (e.g., norepinephrine, dopamine, phenylephrine, epinephrine, or vasopressin and norepinephrine), e.g., as described in Table 5A, Table 5B, and Table 6.

[0386] In other cases, tocilizumab is administered as a premedication, e.g., administered to a subject prior to administration of the bispecific anti-FcRH5 / anti-CD3 antibody. In some cases, tocilizumab is administered as a premedication in cycle 1, e.g., prior to the first dose (C1D1), the second dose (C1D2), and / or the third dose (C1D3) of the bispecific anti-FcRH5 / anti-CD3 antibody. In some aspects, tocilizumab is administered intravenously to a subject in a single dose of about 8 mg / kg.

[0387] CRS symptoms and classification

[0388] CRS is graded according to the modified cytokine release syndrome grading system established in the following literature: Lee et al., Blood, 124: 188-195, 2014; or Lee et al., Biol Blood Marrow Transplant, 25 (4): 625-638, 2019, as described in Table 5A. In addition to the diagnostic criteria, recommended CRS management based on its severity (including early intervention with corticosteroids and / or anti-cytokine therapy) is also provided and mentioned in Tables 5A and 5B.

[0389] Mild to moderate CRS and / or infusion-related reactions (IRR) may include symptoms such as fever, headache, and myalgia, and may be treated symptomatically with analgesics, antipyretics, and antihistamines as needed. Severe or life-threatening manifestations of CRS and / or IRR, such as hypotension, tachycardia, dyspnea, or chest discomfort, should be treated aggressively with supportive and resuscitative measures as indicated, including the use of high-dose corticosteroids, IV fluids, intensive care unit admission, and other supportive measures. Severe CRS may be associated with other clinical sequelae, such as disseminated intravascular coagulation, capillary leak syndrome, or macrophage activation syndrome (MAS). The standard of care for severe or life-threatening CRS caused by immune-based therapies has not been established; case reports and recommendations for the use of anti-cytokine therapies such as tocilizumab have been published (Teachey et al., Blood, 121:5154-5157, 2013; Lee et al., Blood, 124:188-195, 2014; Maude et al., New Engl J Med, 371:1507-1517, 2014).

[0390] As shown in Table 5A, even subjects with extensive comorbidities who develop moderate manifestations of CRS should be closely monitored, and admission to the intensive care unit and administration of tocilizumab should be considered.

[0391] Tocilizumab as premedication

[0392] In some aspects, an effective amount of tocilizumab is administered as a premedication (prevention), for example, administered to a subject before administering a bispecific antibody (e.g., administered about 2 hours before administering the bispecific antibody). Tocilizumab administered as a premedication can reduce the frequency or severity of CRS. In some aspects, tocilizumab is administered as a premedication in the first cycle, for example, before the first dose (C1D1; Cycle 1, Dose 1), the second dose (C1D2; Cycle 1, Dose 2) and / or the third dose (C1D3; Cycle 1, Dose 3) of the bispecific antibody. In some aspects, tocilizumab is administered intravenously to a subject at a single dose of about 1 mg / kg to about 15 mg / kg (e.g., about 4 mg / kg to about 10 mg / kg, for example, about 6 mg / kg to about 10 mg / kg, for example, about 8 mg / kg). In some aspects, tocilizumab is administered intravenously to a subject at a single dose of about 8 mg / kg. In some aspects, tocilizumab is administered intravenously to a subject at a single dose of about 8 mg / kg (maximum 800 mg) for patients weighing 30 kg or more, and at a dose of about 12 mg / kg for patients weighing less than 30 kg. Other anti-IL-6R antibodies that can be used in combination with tocilizumab include sarilumab, vobarilizumab (ALX-0061), SA-237, and variants thereof.

[0393] For example, in one aspect, the bispecific antibody is combined with tocilizumab Co-administration, where tocilizumab is administered first to the subject The bispecific antibody is then administered alone (e.g., the subject is treated with tocilizumab pre-treatment).

[0394] In some aspects, relative to patients not treated with tocilizumab as a pre-medication, in patients treated with tocilizumab as a pre-medication, the incidence of CRS (e.g., grade 1 CRS, grade 2 CRS, and / or grade 3+ CRS) is reduced. In some aspects, relative to patients not treated with tocilizumab as a pre-medication, in patients treated with tocilizumab as a pre-medication, less intervention is required to treat CRS (e.g., less need for additional tocilizumab, IV infusion, steroids, or O 2 In some aspects, the severity of CRS symptoms is reduced (e.g., limited to fever and chills) in patients treated with tocilizumab as a premedication relative to patients not treated with tocilizumab as a premedication.

[0395] Tocilizumab for the treatment of CRS

[0396] In some aspects, the subject experiences a CRS event during treatment with the therapeutic bispecific antibody, and an effective amount of tocilizumab is administered to manage the CRS event.

[0397] In some aspects, the subject develops a CRS event (e.g., a CRS event occurs after treatment with the bispecific antibody, e.g., a CRS event occurs after a first dose or a subsequent dose of the bispecific antibody), and the method further comprises treating a symptom of the CRS event while treatment with the bispecific antibody is suspended.

[0398] In some aspects, the subject experiences a CRS event, and the method further comprises administering to the subject an effective amount of an interleukin-6 receptor (IL-6R) antagonist (e.g., an anti-IL-6R antibody, such as tocilizumab) while treatment with the bispecific antibody is suspended. ) to manage CRS events. In some aspects, an IL-6R antagonist (e.g., tocilizumab) is administered intravenously to a subject at a single dose of about 1 mg / kg to about 15 mg / kg (e.g., about 4 mg / kg to about 10 mg / kg, for example, about 6 mg / kg to about 10 mg / kg, for example, about 8 mg / kg). In some aspects, tocilizumab is administered intravenously to a subject at a single dose of about 8 mg / kg. Other anti-IL-6R antibodies that can be used in combination with tocilizumab include sarilumab, vobarilizumab (ALX-0061), SA-237, and variants thereof.

[0399] In some aspects, the CRS event does not subside or worsen within 24 hours of treating the symptoms of the CRS event, and the method further includes administering to the subject one or more additional doses of an IL-6R antagonist (e.g., an anti-IL-6R antibody, such as tocilizumab) to manage the CRS event, for example, at a dose of about 1 mg / kg to about 15 mg / kg, for example, about 4 mg / kg to about 10 mg / kg, for example, about 6 mg / kg to about 10 mg / kg, for example, about 8 mg / kg. One or more additional doses of tocilizumab are administered intravenously to the subject. In some aspects, one or more additional doses of tocilizumab are administered intravenously to the subject in a single dose of about 8 mg / kg.

[0400] In some aspects, the method further includes administering an effective amount of a corticosteroid to the subject. A corticosteroid can be administered intravenously to the subject. In some aspects, the corticosteroid is methylprednisone (methylprednisolone). In some cases, methylprednisone is administered at a dosage of about 1mg / kg to about 5mg / kg per day, for example, about 2mg / kg per day. In some cases, the corticosteroid is dexamethasone. In some cases, dexamethasone is administered at a dosage of about 10mg (for example, administered intravenously with a single dose of about 10mg) or with a dosage of about 0.5mg / kg / days.

[0401] If the IL-6R antagonist (e.g., tocilizumab) alone cannot manage the CRS event, a corticosteroid such as methylprednisolone or dexamethasone may be administered to the subject. In some aspects, the symptoms of the CRS event are further treated with a high-dose vasopressor (e.g., norepinephrine, dopamine, phenylephrine, epinephrine, or vasopressin and norepinephrine), for example, as described in Table 5A, Table 5B, and Table 6. Table 2 and Table 5A provide detailed information on tocilizumab treatment of severe or life-threatening CRS.

[0402] Manage CRS events by level

[0403] The management of CRS events can be tailored based on the grade of CRS ( Table 2 and Table 5A ) and the presence of comorbidities. Table 2 provides suggestions for the management of CRS syndrome by grade.

[0404] Table 2. Recommendations for the management of cytokine release syndrome

[0405]

[0406]

[0407]

[0408]

[0409] CRS = cytokine release syndrome; HLH = hemophagocytic lymphohistiocytosis; ICU = intensive care unit; IV = intravenous; MAS = macrophage activation syndrome.

[0410] Note: CRS is a disorder characterized by nausea, headache, tachycardia, hypotension, rash, shortness of breath, and kidney, coagulation, liver, and nervous system disorders; it is caused by the release of cytokines from cells (Lee et al., Blood, 124: 188-195, 2014).

[0411] aSee Table 5A for description of symptom classification.

[0412] b Based on the CRS management guidelines of Lee et al., Blood, 124:188-195, 2014.

[0413] cSee Table 5B for description and calculation of high-dose pressors.

[0414] dIf the patient does not experience CRS during the next infusion at a 50% reduced rate, the infusion rate can be increased to the initial rate in subsequent cycles. However, if this patient experiences another CRS event, the infusion rate should be reduced by 25%-50%, depending on the severity of the event.

[0415] Management of Level 2 CRS Events

[0416] If a subject develops a Grade 2 CRS event after administration of a therapeutic bispecific antibody (e.g., a Grade 2 CRS event occurs in the absence of comorbidities or in the presence of minimal comorbidities), the method may further include treating the symptoms of the Grade 2 CRS event while suspending treatment with the bispecific antibody. If a Grade 2 CRS event then resolves to a Grade 1 CRS event for at least three consecutive days, the method may further include resuming treatment with the bispecific antibody without changing the dose. On the other hand, if a Grade 2 CRS event does not resolve within 24 hours of treating the symptoms of a Grade 2 CRS event, or deteriorates to a Grade 3 CRS event, the method may further include administering to the subject an effective amount of an interleukin-6 receptor (IL-6R) antagonist (e.g., an anti-IL-6R antibody, such as tocilizumab ) to manage grade 2 or ≥ grade 3 CRS events. In some cases, tocilizumab is administered intravenously to a subject at a single dose of about 8 mg / kg. Other anti-IL-6R antibodies that can be used in combination with tocilizumab include sarilumab, vobarilizumab (ALX-0061), SA-237, and variants thereof.

[0417] If the subject develops a Grade 2 CRS event in the presence of extensive comorbidities after administration of the therapeutic bispecific antibody, the method may further comprise: administering to the subject an IL-6R antagonist (e.g., an anti-IL-6R antibody, e.g., tocilizumab ) to manage the grade 2 CRS event, while suspending treatment with the bispecific antibody. In some cases, the first dose of tocilizumab is administered intravenously to the subject at a dose of about 8 mg / kg. Other anti-IL-6R antibodies that can be used in combination with tocilizumab include sarilumab, vobarilizumab (ALX-0061), SA-237 and variants thereof. In some cases, if the grade 2 CRS event resolves to ≤grade 1 CRS event within two weeks, the method further includes resuming treatment with the bispecific antibody at a reduced dose. In some cases, if the event occurs during an infusion or within 24 hours thereof, the smaller dose is 50% of the initial infusion rate of the previous cycle. On the other hand, if a grade 2 CRS event does not subside or worsen to a grade 3 CRS event within 24 hours of treating the symptoms of the grade 2 CRS event, the method may further include: administering to the subject one or more (e.g., one, two, three, four, or five or more) additional doses of an IL-6R antagonist (e.g., an anti-IL-6R antibody, such as tocilizumab) to manage a grade 2 or grade 3 CRS event. In some specific cases, a grade 2 CRS event does not subside within 24 hours of treating the symptoms of the grade 2 CRS event, or worsens to a grade 3 CRS event, and the method may further include administering to the subject one or more additional doses of tocilizumab to manage a grade 2 or grade 3 CRS event. In some cases, one or more additional doses of tocilizumab are administered intravenously to the subject at a dose of about 1 mg / kg to about 15 mg / kg (e.g., about 4 mg / kg to about 10 mg / kg, for example, about 6 mg / kg to about 10 mg / kg, for example, about 8 mg / kg). In some cases, the method further includes administering an effective amount of a corticosteroid to the subject. A corticosteroid may be administered before, after, or simultaneously with one or more additional doses of tocilizumab or other anti-IL-6R antibodies. In some cases, a corticosteroid is administered intravenously to the subject. In some cases, the corticosteroid is methylprednisolone. In some cases, methylprednisolone is administered at a dose of about 1 mg / kg to about 5 mg / kg per day, for example, about 2 mg / kg per day. In some cases, the corticosteroid is dexamethasone. In some cases, dexamethasone is administered at a dose of about 10 mg (e.g., administered intravenously with a single dose of about 10 mg) or at a dose of about 0.5 mg / kg / day.

[0418] Management of Level 3 CRS Events

[0419] If the subject develops a Grade 3 CRS event after administration of the therapeutic bispecific antibody, the method may further comprise: administering to the subject an IL-6R antagonist (e.g., an anti-IL-6R antibody, e.g., tocilizumab) ) to manage the grade 3 CRS event while suspending treatment with the bispecific antibody. In some cases, the first dose of tocilizumab is administered intravenously to the subject at a dose of about 8 mg / kg. Other anti-IL-6R antibodies that can be used in combination with tocilizumab include sarilumab, vobarilizumab (ALX-0061), SA-237 and variants thereof. In some cases, the subject recovers within 8 hours after treatment with the bispecific antibody (e.g., no fever and vasopressors are discontinued), and the method further includes resuming treatment with the bispecific antibody at a reduced dose. In some cases, if the event occurs during an infusion or within 24 hours thereof, the smaller dose is 50% of the initial infusion rate of the previous cycle. In other cases, if the grade 3 CRS event does not subside or worsens to a grade 4 CRS event within 24 hours of treating the symptoms of the grade 3 CRS event, the method may further include: administering to the subject one or more (e.g., one, two, three, four, or five or more) additional doses of an IL-6R antagonist (e.g., an anti-IL-6R antibody, such as tocilizumab) to manage a grade 3 or 4 CRS event. In some specific cases, the grade 3 CRS event does not subside or worsens to a grade 4 CRS event within 24 hours of treating the symptoms of the grade 3 CRS event, and the method further includes administering to the subject one or more additional doses of tocilizumab to manage a grade 3 or 4 CRS event. In some cases, one or more additional doses of tocilizumab are administered intravenously to the subject at a dose of about 1 mg / kg to about 15 mg / kg (e.g., about 4 mg / kg to about 10 mg / kg, for example, about 6 mg / kg to about 10 mg / kg, for example, about 8 mg / kg). In some cases, the method further includes administering an effective amount of a corticosteroid to the subject. A corticosteroid may be administered before, after, or simultaneously with one or more additional doses of tocilizumab or other anti-IL-6R antibodies. In some cases, a corticosteroid is administered intravenously to the subject. In some cases, the corticosteroid is methylprednisolone. In some cases, methylprednisolone is administered at a dose of about 1 mg / kg to about 5 mg / kg per day, for example, about 2 mg / kg per day. In some cases, the corticosteroid is dexamethasone. In some cases, dexamethasone is administered at a dose of about 10 mg (e.g., administered intravenously with a single dose of about 10 mg) or at a dose of about 0.5 mg / kg / day.

[0420] Management of Level 4 CRS Events

[0421] If the subject develops a Grade 4 CRS event after administration of the therapeutic bispecific antibody, the method may further comprise: administering to the subject an IL-6R antagonist (e.g., an anti-IL-6R antibody, e.g., tocilizumab) ) to manage the Grade 4 CRS event, and permanently discontinue treatment with the bispecific antibody. In some cases, the first dose of tocilizumab is administered intravenously to the subject at a dose of about 8 mg / kg. Other anti-IL-6R antibodies that can be used in combination with tocilizumab include sarilumab, vobarilizumab (ALX-0061), SA-237 and variants thereof. In some cases, a Grade 4 CRS event may subside within 24 days after treating the symptoms of the Grade 4 CRS event. If the Grade 4 CRS event does not subside within 24 hours of treating the symptoms of the Grade 4 CRS event, the method may further include administering an IL-6R antagonist (e.g., an anti-IL-6R antibody, such as tocilizumab) to the subject. ) to manage grade 4 CRS events. In some specific cases, grade 4 CRS events do not subside within 24 hours of treating the symptoms of the grade 4 CRS events, and the method further includes administering one or more (e.g., one, two, three, four, or five or more) additional doses of tocilizumab to the subject to manage grade 4 CRS events. In some cases, one or more additional doses of tocilizumab are administered intravenously to the subject at a dosage of about 1 mg / kg to about 15 mg / kg (e.g., about 4 mg / kg to about 10 mg / kg, for example, about 6 mg / kg to about 10 mg / kg, for example, about 8 mg / kg). In some cases, the method further includes administering an effective amount of corticosteroids to the subject. Corticosteroids can be administered before, after, or simultaneously with one or more additional doses of tocilizumab or other anti-IL-6R antibodies. In some cases, corticosteroids are administered intravenously to the subject. In some cases, the corticosteroid is methylprednisolone. In some cases, methylprednisolone is administered at a dose of about 1 mg / kg per day to about 5 mg / kg per day, e.g., about 2 mg / kg per day. In some cases, the corticosteroid is dexamethasone. In some cases, dexamethasone is administered at a dose of about 10 mg (e.g., administered intravenously in a single dose of about 10 mg) or at a dose of about 0.5 mg / kg / day.

[0422] ii. Corticosteroids

[0423] In another case, the additional therapeutic agent is an effective amount of a corticosteroid. A corticosteroid can be administered intravenously to a subject. In some aspects, the corticosteroid is methylprednisone. Methylprednisone can be administered to a subject at a dosage of about 80 mg. In other aspects, the corticosteroid is dexamethasone. Dexamethasone can be administered to a subject at a dosage of about 80 mg. In some aspects, a corticosteroid (e.g., methylprednisone or dexamethasone) is administered to a subject before administering a bispecific anti-FcRH5 / anti-CD3 antibody (e.g., silvostomumab) (e.g., one hour before administering a bispecific anti-FcRH5 / anti-CD3 antibody).

[0424] iii. Acetaminophen or paracetamol

[0425] In another instance, the additional therapeutic agent is an effective amount of acetaminophen or paracetamol. Acetaminophen or paracetamol can be administered orally to the subject, for example, at a dose between about 500 mg and about 1000 mg. In some aspects, acetaminophen or paracetamol is administered to the subject as a premedication, for example, prior to administration of the bispecific anti-FcRH5 / anti-CD3 antibody (e.g., silvostomumab).

[0426] iv. Diphenhydramine

[0427] In another instance, the additional therapeutic agent is an effective amount of diphenhydramine. Diphenhydramine can be administered orally to the subject, for example, at a dose of between about 25 mg and about 50 mg. In some aspects, diphenhydramine is administered to the subject as a premedication, for example, prior to administration of a bispecific anti-FcRH5 / anti-CD3 antibody (e.g., silvostomumab).

[0428] v. Anti-myeloma agents

[0429] In another case, the additional therapeutic agent is an effective amount of an anti-myeloma agent, such as an anti-myeloma agent that enhances and / or supplements T cell-mediated myeloma cell killing. The anti-myeloma agent may be, for example, an IMiD (e.g., pomalidomide, thalidomide or lenalidomide), daratumumab and / or B cell maturation antigen (BCMA) directed therapy (e.g., antibody-drug conjugates (BCMA-ADC) targeting BCMA). In some aspects, the anti-myeloma agent is administered in a four-week cycle.

[0430] In some aspects, the anti-myeloma agent is pomalidomide. In some aspects, pomalidomide is orally administered at a dose of 4 mg on days 1-28 of a 28-day cycle. In some aspects, pomalidomide is administered in combination with dexamethasone, for example, in combination with dexamethasone administered on days 1, 8, 15, and 22 of a 28-day cycle.

[0431] In some aspects, the anti-myeloma agent is daratumumab. In some aspects, daratumumab is administered by intravenous infusion (e.g., 3-5 hour infusion) with a dosage of 16 mg / kg once a week, once every two weeks, or once every four weeks. In some aspects, daratumumab is administered by intravenous infusion (e.g., 3-5 hour infusion) with a dosage of 16 mg / kg, once a week for two 28-day cycles, once every two weeks for three 28-day cycles, and once every four weeks for one or more additional cycles.

[0432] vi. Other combination therapies

[0433] In some aspects, the one or more additional therapeutic agents include a PD-1 axis binding antagonist, an immunomodulatory agent, an anti-tumor agent, a chemotherapeutic agent, a growth inhibitory agent, an anti-angiogenic agent, radiation therapy, a cytotoxic agent, a cell-based therapy, or a combination thereof.

[0434] PD-1 axis binding antagonists

[0435] In some aspects, the additional therapeutic agent is a PD-1 axis binding antagonist. Exemplary PD-1 axis binding antagonists include agents that inhibit the interaction of the PD-1 axis binding partner with one or more of its binding partners, thereby eliminating T cell dysfunction caused by signal transduction on the PD-1 signal transduction axis, resulting in restoration or enhancement of T cell function (e.g., proliferation, cytokine production, target cell killing). As used herein, PD-1 axis binding antagonists include PD-1 binding antagonists, PD-L1 binding antagonists, and PD-L2 binding antagonists. Any suitable PD-1 axis binding antagonist can be used.

[0436] In some cases, the PD-L1 binding antagonist inhibits the binding of PD-L1 to one or more of its ligand binding partners. In other cases, the PD-L1 binding antagonist inhibits the binding of PD-L1 to PD-1. In some other cases, the PD-L1 binding antagonist inhibits the binding of PD-L1 to B7-1. In some cases, the PD-L1 binding antagonist inhibits the binding of PD-L1 to both PD-1 and B7-1. The PD-L1 binding antagonist can be, but is not limited to, an antibody, an antigen binding fragment thereof, an immunoadhesin, a fusion protein, an oligopeptide or a small molecule. In some cases, the PD-L1 binding antagonist is a small molecule that inhibits PD-L1 (e.g., GS-4224, INCB086550, MAX-10181, INCB090244, CA-170 or ABSK041). In some cases, the PD-L1 binding antagonist is a small molecule that inhibits PD-L1 and VISTA. In some cases, the PD-L1 binding antagonist is CA-170 (also known as AUPM-170). In some cases, the PD-L1 binding antagonist is a small molecule that inhibits PD-L1 and TIM3. In some cases, the small molecule is a compound described in WO 2015 / 033301 and / or WO 2015 / 033299.

[0437] In some cases, the PD-L1 binding antagonist is an anti-PD-L1 antibody. A variety of anti-PD-L1 antibodies are contemplated and described herein. In any case herein, the isolated anti-PD-L1 antibody can bind to human PD-L1 (e.g., human PD-L1 shown in UniProtKB / Swiss-Prot Accession No. Q9NZQ7-1, or a variant thereof). In some cases, the anti-PD-L1 antibody is capable of inhibiting the binding between PD-L1 and PD-1 and / or between PD-L1 and B7-1. In some cases, the anti-PD-L1 antibody is a monoclonal antibody. In some cases, the anti-PD-L1 antibody is an antibody fragment selected from the group consisting of: Fab, Fab'-SH, Fv, scFv and (Fab') 2In some cases, the anti-PD-L1 antibody is a humanized antibody. In some cases, the anti-PD-L1 antibody is a human antibody. Exemplary anti-PD-L1 antibodies include atezolizumab, MDX-1105, MEDI4736 (durvalumab), MSB0010718C (avelumab), SHR-1316, CS1001, envolimab, TQB2450, ZKAB001, LP-002, CX-072, IMC-001, KL-A167, APL-502, coxilimab, lodalimab, FAZ053, TG-1501, BGB-A333, BCD-135, AK-106, LDP, GR1405, HLX20, MSB2311, RC98, PDL-GEX, KD036, KY1003, YBL-007, and HS-636. In some instances, the anti-PD-L1 antibody is atezolizumab. Examples of anti-PD-L1 antibodies useful in the methods of the invention and methods for their preparation are described in International Patent Application Publication No. WO 2010 / 077634 and U.S. Patent No. 8,217,149, each of which is incorporated herein by reference in its entirety.

[0438] In some instances, the anti-PD-L1 antibody is avelumab (CAS Registry Number: 1537032-82-8). Avelumab, also known as MSB0010718C, is a human monoclonal IgG1 anti-PD-L1 antibody (Merck KGaA, Pfizer).

[0439] In some instances, the anti-PD-L1 antibody is durvalumab (CAS Registry Number: 1428935-60-7).Durvalumab, also known as MEDI4736, is an Fc-optimized human monoclonal IgG1κ anti-PD-L1 antibody described in WO 2011 / 066389 and US 2013 / 034559 (MedImmune, AstraZeneca).

[0440] In some instances, the anti-PD-L1 antibody is MDX-1105 (Bristol Myers Squibb). MDX-1105, also known as BMS-936559, is an anti-PD-L1 antibody described in WO 2007 / 005874.

[0441] In some instances, the anti-PD-L1 antibody is LY3300054 (Eli Lilly).

[0442] In some instances, the anti-PD-L1 antibody is STI-A1014 (Sorrento). STI-A1014 is a human anti-PD-L1 antibody.

[0443] In some cases, the anti-PD-L1 antibody is KN035 (Suzhou Alphamab). KN035 is a single domain antibody (dAB) generated from a camelid phage display library.

[0444] In some cases, the anti-PD-L1 antibody comprises a cleavable portion or linker that, when cleaved (e.g., by a protease in the tumor microenvironment), activates the antibody antigen-binding domain to bind its antigen, e.g., by removing a non-binding steric portion. In some cases, the anti-PD-L1 antibody is CX-072 (CytomX Therapeutics).

[0445] In some instances, the anti-PD-L1 antibody comprises six HVR sequences (e.g., three heavy chain HVRs and three light chain HVRs) and / or heavy chain variable domains and light chain variable domains from an anti-PD-L1 antibody described in US20160108123, WO 2016 / 000619, WO 2012 / 145493, U.S. Pat. No. 9,205,148, WO 2013 / 181634, or WO 2016 / 061142.

[0446] In some cases, the PD-1 axis binding antagonist is a PD-1 binding antagonist. For example, in some cases, the PD-1 binding antagonist inhibits the binding of PD-1 to one or more of its ligand binding partners. In some cases, the PD-1 binding antagonist inhibits the binding of PD-1 to PD-L1. In other cases, the PD-1 binding antagonist inhibits the binding of PD-1 to PD-L2. In some other cases, the PD-1 binding antagonist inhibits the binding of PD-1 to both PD-L1 and PD-L2. The PD-1 binding antagonist can be, but is not limited to, an antibody, an antigen binding fragment thereof, an immunoadhesin, a fusion protein, an oligopeptide or a small molecule. In some cases, the PD-1 binding antagonist is an immunoadhesin (e.g., an extracellular or PD-1 binding portion of a PD-L1 or PD-L2 fused to a constant region (e.g., an Fc region of an immunoglobulin sequence)). For example, in some cases, the PD-1 binding antagonist is an Fc fusion protein. In some cases, the PD-1 binding antagonist is AMP-224. AMP-224 is also called B7-DCIg, which is a PD-L2-Fc fusion soluble receptor described in WO 2010 / 027827 and WO 2011 / 066342. In some cases, the PD-1 binding antagonist is a peptide or a small molecule compound. In some cases, the PD-1 binding antagonist is AUNP-12 (Pierre Fabre / Aurigene). See, for example, WO 2012 / 168944, WO 2015 / 036927, WO2015 / 044900, WO 2015 / 033303, WO 2013 / 144704, WO 2013 / 132317, and WO 2011 / 161699. In some instances, a PD-1 binding antagonist is a small molecule that inhibits PD-1.

[0447] In some cases, the PD-1 binding antagonist is an anti-PD-1 antibody. A variety of anti-PD-1 antibodies can be utilized in the methods and uses disclosed herein. In any case herein, the PD-1 antibody can bind to human PD-1 or a variant thereof. In some cases, the anti-PD-1 antibody is a monoclonal antibody. In some cases, the anti-PD-1 antibody is an antibody fragment selected from the group consisting of: Fab, Fab', Fab'-SH, Fv, scFv and (Fab') 2Fragment. In some cases, the anti-PD-1 antibody is a humanized antibody. In other cases, the anti-PD-1 antibody is a human antibody. Exemplary anti-PD-1 antagonist antibodies include nivolumab, pembrolizumab, MEDI-0680, PDR001 (spartalizumab), REGN2810 (cemiprilimab), BGB-108, palolizumab, carrelizumab, sintilimab, tislelizumab, toripalimab, dotalimumab, rivulimab, sazanlimab, penampalimab, CS1003, HLX10, SCT-I10A, sepalimab, batilizumab, genomumab, BI 754091, silimab, YBL-006, BAT1306, HX008, buglilimab, AMG 404, CX-188, JTX-4014, 609A, Sym021, LZM009, F520, SG001, AM0001, ENUM 244C8, ENUM 388D4, STI-1110, AK-103, and hAb21.

[0448] In some instances, the anti-PD-1 antibody is nivolumab (CAS Registry Number: 946414-94-4). Nivolumab (Bristol-Myers Squibb / Ono Pharmaceutical (Ono)), also known as MDX-1106-04, MDX-1106, ONO-4538, BMS-936558 and It is the anti-PD-1 antibody described in WO 2006 / 121168.

[0449] In some instances, the anti-PD-1 antibody is pembrolizumab (CAS Registry Number: 1374853-91-4). Pembrolizumab (Merck), also known as MK-3475, Merck 3475, pembrolizumab, SCH-900475, and It is the anti-PD-1 antibody described in WO 2009 / 114335.

[0450] In some instances, the anti-PD-1 antibody is MEDI-0680 (AMP-514; AstraZeneca). MEDI-0680 is a humanized IgG4 anti-PD-1 antibody.

[0451] In some cases, the anti-PD-1 antibody is PDR001 (CAS Registry No. 1859072-53-9; Novartis). PDR001 is a humanized IgG4 anti-PD-1 antibody that blocks the binding of PD-L1 and PD-L2 to PD-1.

[0452] In some instances, the anti-PD-1 antibody is REGN2810 (Regeneron). REGN2810 is a human anti-PD-1 antibody.

[0453] In some instances, the anti-PD-1 antibody is BGB-108 (BeiGene).

[0454] In some instances, the anti-PD-1 antibody is BGB-A317 (BeiGene).

[0455] In some cases, the anti-PD-1 antibody is JS-001 (Shanghai Junshi Biosciences). JS-001 is a humanized anti-PD-1 antibody.

[0456] In some instances, the anti-PD-1 antibody is STI-A1110 (Sorrento). STI-A1110 is a human anti-PD-1 antibody.

[0457] In some instances, the anti-PD-1 antibody is INCSHR-1210 (Incyte). INCSHR-1210 is a human IgG4 anti-PD-1 antibody.

[0458] In some instances, the anti-PD-1 antibody is PF-06801591 (Pfizer).

[0459] In some instances, the anti-PD-1 antibody is TSR-042 (also known as ANB011; Tesaro / AnaptysBio).

[0460] In some instances, the anti-PD-1 antibody is AM0001 (ARMO Biosciences).

[0461] In some cases, the anti-PD-1 antibody is ENUM 244C8 (Enumeral Biomedical Holdings). ENUM 244C8 is an anti-PD-1 antibody that inhibits the function of PD-1 without preventing the binding of PD-L1 to PD-1.

[0462] In some cases, the anti-PD-1 antibody is ENUM 388D4 (Enumeral Biomedical Holdings). ENUM 388D4 is an anti-PD-1 antibody that competitively inhibits the binding of PD-L1 to PD-1.

[0463] In some cases, the anti-PD-1 antibody comprises six HVR sequences (e.g., three heavy chain HVRs and three light chain HVRs) and / or heavy chain variable domains and light chain variable domains from the anti-PD-1 antibodies described in WO 2015 / 112800, WO 2015 / 112805, WO 2015 / 112900, US20150210769, WO 2016 / 089873, WO 2015 / 035606, WO 2015 / 085847, WO 2014 / 206107, WO 2012 / 145493, US 9,205,148, WO 2015 / 119930, WO 2015 / 119923, WO 2016 / 032927, WO 2014 / 179664, WO 2016 / 106160 and WO 2014 / 194302.

[0464] In some cases, the PD-1 axis binding antagonist is a PD-L2 binding antagonist. In some cases, the PD-L2 binding antagonist is a molecule that inhibits the binding of PD-L2 to its ligand binding partner. In a specific aspect, the PD-L2 binding ligand partner is PD-1. The PD-L2 binding antagonist can be, but is not limited to, an antibody, an antigen binding fragment thereof, an immunoadhesin, a fusion protein, an oligopeptide, or a small molecule.

[0465] In some cases, the PD-L2 binding antagonist is an anti-PD-L2 antibody. In any case herein, the anti-PD-L2 antibody can bind to human PD-L2 or a variant thereof. In some cases, the anti-PD-L2 antibody is a monoclonal antibody. In some cases, the anti-PD-L2 antibody is an antibody fragment selected from the group consisting of: Fab, Fab', Fab'-SH, Fv, scFv and (Fab') 2 Fragments. In some cases, the anti-PD-L2 antibody is a humanized antibody. In other cases, the anti-PD-L2 antibody is a human antibody. In further specific aspects, the anti-PD-L2 antibody has reduced or minimal effector function. In further specific aspects, the minimal effector function comes from an "effectorless Fc mutation" or an aglycosylation mutation. In further cases, the effectorless Fc mutation is an N297A or D265A / N297A substitution in the constant region. In some cases, the isolated anti-PD-L2 antibody is aglycosylated.

[0466] Growth inhibitors

[0467] In some aspects, the additional therapeutic agent is a growth inhibitor. Exemplary growth inhibitors include agents that block cell cycle progression outside the S phase, such as agents that induce G1 arrest (e.g., DNA alkylating agents such as tamoxifen, prednisone, dacarbazine, mechlorethamine, cisplatin, methotrexate, 5-fluorouracil, or ara-C) or agents that arrest in the M phase (e.g., vincristine, vinblastine, taxanes (e.g., paclitaxel and docetaxel), doxorubicin, epirubicin, daunorubicin, etoposide, or bleomycin).

[0468] Radiation therapy

[0469] In some aspects, the additional therapeutic agent is radiation therapy. Radiation therapy includes the use of directed gamma or beta rays to induce sufficient damage to cells, thereby limiting the ability of cells to function normally or completely destroying cells. Typical treatment is a single administration, and a typical dosage range is 10 to 200 units (Gray) per day.

[0470] Cytotoxic agents

[0471] In some aspects, the additional therapeutic agent is a cytotoxic agent, such as a substance that inhibits or prevents cell function and / or causes cell death or destruction. Cytotoxic agents include, but are not limited to, radioactive isotopes (e.g., At 211 ,I 131 ,I 125 , Y 90 、Re 186 、Re 188 、Sm 153 、Bi 212 , P 32 , Pb 212 and radioactive isotopes of Lu); chemotherapeutic agents or drugs (e.g., methotrexate, doxorubicin, vinca alkaloids (vincristine, vinblastine, etoposide), doxorubicin, melphalan, mitomycin C, chlorambucil, daunorubicin or other intercalating agents); growth inhibitors; 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 anti-tumor or anti-cancer drugs.

[0472] Anticancer therapy

[0473] In some cases, the method comprises administering to the individual an anti-cancer therapy (e.g., an anti-tumor agent, a chemotherapeutic agent, a growth inhibitory agent, an anti-angiogenic agent, a radiation therapy, or a cytotoxic agent) other than or in addition to the bispecific anti-FcRH5 / anti-CD3 antibody.

[0474] In some cases, the method further involves administering an effective amount of an additional therapeutic agent to the patient. In some cases, the additional therapeutic agent is selected from the group consisting of the following items: anti-tumor agents, chemotherapeutic agents, growth inhibitors, anti-angiogenic agents, radiotherapy, cytotoxic agents and combinations thereof. In some cases, bispecific anti-FcRH5 / anti-CD3 antibodies (e.g., silvostomumab) and lenalidomide can be co-administered with chemotherapy or chemotherapeutic agents. In some cases, bispecific anti-FcRH5 / anti-CD3 antibodies can be co-administered with radiotherapy agents. In some cases, bispecific anti-FcRH5 / anti-CD3 antibodies can be co-administered with targeted therapy or targeted therapeutic agents. In some cases, bispecific anti-FcRH5 / anti-CD3 antibodies can be co-administered with immunotherapy or immunotherapeutic agents (e.g., monoclonal antibodies). In some cases, the additional therapeutic agent is an agonist for costimulatory molecules. In some cases, the additional therapeutic agent is an antagonist for co-inhibitory molecules.

[0475] Without wishing to be bound by theory, it is believed that enhancing T cell stimulation by promoting co-stimulatory molecules or by inhibiting co-inhibitory molecules can promote tumor cell death, thereby treating or delaying the development of cancer. In some cases, bispecific anti-FcRH5 / anti-CD3 antibodies can be co-administered with agonists for co-stimulatory molecules. In some cases, co-stimulatory molecules may include CD40, CD226, CD28, OX40, GITR, CD137, CD27, HVEM or CD127. In some cases, agonists for co-stimulatory molecules are agonist antibodies that bind to CD40, CD226, CD28, OX40, GITR, CD137, CD27, HVEM or CD127. In some cases, bispecific anti-FcRH5 / anti-CD3 antibodies can be co-administered with antagonists for co-inhibitory molecules. In some cases, the co-inhibitory molecule may include CTLA-4 (also known as CD152), TIM-3, BTLA, VISTA, LAG-3, B7-H3, B7-H4, IDO, TIGIT, MICA / B, or arginase. In some cases, the antagonist to the co-inhibitory molecule is an antagonist antibody that binds to CTLA-4, TIM-3, BTLA, VISTA, LAG-3, B7-H3, B7-H4, IDO, TIGIT, MICA / B, or arginase.

[0476] In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be administered in combination with an antagonist to CTLA-4 (also known as CD152), such as a blocking antibody. In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be administered in combination with ipilimumab (also known as MDX-010, MDX-101, or ). In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be co-administered with tremelimumab (also known as ticilimumab or CP-675,206). In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be co-administered with an antagonist to B7-H3 (also known as CD276), such as a blocking antibody. In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be co-administered with MGA271. In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be co-administered with an antagonist to TGF-β, such as metilimumab (also known as CAT-192), fresolimumab (also known as GC1008), or LY2157299.

[0477] In some cases, bispecific anti-FcRH5 / anti-CD3 antibodies can be administered in combination with a therapy comprising adoptive transfer of T cells (e.g., cytotoxic T cells or CTLs) expressing a chimeric antigen receptor (CAR). In some cases, bispecific anti-FcRH5 / anti-CD3 antibodies can be administered in combination with a therapy comprising adoptive transfer of T cells comprising a dominant negative TGFβ receptor, such as a dominant negative TGFβ type II receptor. In some cases, bispecific anti-FcRH5 / anti-CD3 antibodies can be administered in combination with a therapy comprising a HERCREEM regimen (see, e.g., ClinicalTrials.gov identifier NCT00889954).

[0478] In some cases, bispecific anti-FcRH5 / anti-CD3 antibodies can be co-administered with agonists such as activating antibodies for CD137 (also known as TNFRSF9, 4-1BB or ILA). In some cases, bispecific anti-FcRH5 / anti-CD3 antibodies can be co-administered with urelumab (also known as BMS-663513). In some cases, bispecific anti-FcRH5 / anti-CD3 antibodies can be co-administered with agonists such as activating antibodies for CD40. In some cases, bispecific anti-FcRH5 / anti-CD3 antibodies can be co-administered with CP-870893. In some cases, bispecific anti-FcRH5 / anti-CD3 antibodies can be co-administered with agonists such as CD134 for OX40, such as activating antibodies. In some cases, bispecific anti-FcRH5 / anti-CD3 antibodies can be co-administered with anti-OX40 antibodies (e.g., AgonOX). In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be co-administered with an agonist for CD27, such as an activating antibody. In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be co-administered with CDX-1127. In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be co-administered with an antagonist for indoleamine-2,3-dioxygenase (IDO). In some cases, the IDO antagonist is 1-methyl-D-tryptophan (also known as 1-D-MT).

[0479] In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be administered in combination with an antibody-drug conjugate. In some cases, the antibody-drug conjugate comprises mertansine or monomethyl auristatin E (MMAE). In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be administered in combination with an anti-NaPi2b antibody-MMAE conjugate (also known as DNIB0600A or RG7599). In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be administered in combination with trastuzumab emtansine (also known as T-DM1, ado-trastuzumab emtansine) or In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be administered in combination with DMUC5754A. In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be administered in combination with an antibody-drug conjugate that targets the endothelin B receptor (EDNBR), for example, a conjugate of an antibody to EDNBR with MMAE.

[0480] In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be administered in combination with an anti-angiogenic agent. In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be administered in combination with an antibody to VEGF, such as VEGF-A. In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be administered in combination with bevacizumab (also known as In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be administered in combination with an antibody directed against angiopoietin 2 (also known as Ang2). In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be administered in combination with MEDI3617.

[0481] In some cases, the bispecific anti-FcRH5 / anti-CD3 antibodies can be administered in combination with an anti-tumor agent. In some cases, the bispecific anti-FcRH5 / anti-CD3 antibodies can be administered in combination with a drug that targets CSF-1R (also known as M-CSFR or CD115). In some cases, the bispecific anti-FcRH5 / anti-CD3 antibodies can be administered in combination with anti-CSF-1R (also known as IMC-CS4). In some cases, the bispecific anti-FcRH5 / anti-CD3 antibodies can be administered in combination with an interferon, such as interferon α or interferon γ. In some cases, the bispecific anti-FcRH5 / anti-CD3 antibodies can be administered in combination with Roferon-A (also known as recombinant interferon α-2a). In some cases, the bispecific anti-FcRH5 / anti-CD3 antibodies can be administered in combination with GM-CSF (also known as recombinant human granulocyte macrophage colony stimulating factor, rhu GM-CSF, sargramostim or ). In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be administered in combination with IL-2 (also known as aldesleukin or ). In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be co-administered with IL-12. In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be co-administered with an antibody targeting CD20. In some cases, the antibody targeting CD20 is obinutuzumab (also known as GA101 or ) or rituximab. In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be administered in combination with an antibody targeting GITR. In some cases, the antibody targeting GITR is TRX518.

[0482] In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be administered in combination with a cancer vaccine. In some cases, the cancer vaccine is a peptide cancer vaccine, which in some cases is a personalized peptide vaccine. In some cases, the peptide cancer vaccine is a multivalent long peptide, a polypeptide, a peptide mixture, a hybrid peptide, or a peptide-loaded dendritic cell vaccine (see, e.g., Yamada et al., Cancer Sci. 104: 14-21, 2013). In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be administered in combination with an adjuvant. In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be administered with a TLR agonist such as Poly-ICLC (also known as ), LPS, MPL or CpG ODN. In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be administered in combination with tumor necrosis factor (TNF) α. In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be administered in combination with IL-1. In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be administered in combination with HMGB1. In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be administered in combination with IL-10 antagonists. In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be administered in combination with IL-4 antagonists. In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be administered in combination with IL-13 antagonists. In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be administered in combination with HVEM antagonists. In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be administered in combination with an ICOS agonist, for example, by administering ICOS-L or an agonistic antibody to ICOS. In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be administered in combination with a treatment targeting CX3CL1. In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be administered in combination with a treatment targeting CXCL9. In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be administered in combination with a treatment targeting CXCL10. In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be administered in combination with a treatment targeting CCL5. In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be administered in combination with an LFA-1 or ICAM1 agonist. In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be administered in combination with a selectin agonist.

[0483] In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be administered in combination with a targeted therapy. In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be administered in combination with an inhibitor of B-Raf. In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be administered in combination with vemurafenib (also known as ). In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be administered in combination with dabrafenib (also known as ). In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be administered in combination with erlotinib (also known as ). In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be administered in combination with an inhibitor of MEK, such as MEK1 (also known as MAP2K1) or MEK2 (also known as MAP2K2). In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be administered in combination with cobimetinib (also known as GDC-0973 or XL-518). In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be administered in combination with trametinib (also known as ). In some cases, the bispecific anti-FcRH5 / anti-CD3 antibodies can be co-administered with inhibitors of K-Ras. In some cases, the bispecific anti-FcRH5 / anti-CD3 antibodies can be co-administered with inhibitors of c-Met. In some cases, the bispecific anti-FcRH5 / anti-CD3 antibodies can be co-administered with onartuzumab (also known as MetMAb). In some cases, the bispecific anti-FcRH5 / anti-CD3 antibodies can be co-administered with inhibitors of Alk. In some cases, the bispecific anti-FcRH5 / anti-CD3 antibodies can be co-administered with AF802 (also known as CH5424802 or alectinib). In some cases, the bispecific anti-FcRH5 / anti-CD3 antibodies can be co-administered with inhibitors of phosphatidylinositol 3-kinase (PI3K). In some cases, the bispecific anti-FcRH5 / anti-CD3 antibodies can be co-administered with BKM120. In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be administered in combination with idelalisib (also known as GS-1101 or CAL-101). In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be administered in combination with perifosine (also known as KRX-0401). In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be administered in combination with an inhibitor of Akt. In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be administered in combination with MK2206. In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be administered in combination with GSK690693. In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be administered in combination with GDC-0941. In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be administered in combination with an inhibitor of mTOR. In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be administered in combination with sirolimus (also known as rapamycin). In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be administered in combination with temsirolimus (also known as CCI-779 or ). In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be co-administered with everolimus (also known as RAD001). In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be used in combination with ridaforolimus (also known as AP-23573, MK-8669 or deforolimus). In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be co-administered with OSI-027. In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be co-administered with AZD8055. In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be co-administered with INK128. In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be co-administered with a dual PI3K / mTOR inhibitor. In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be co-administered with XL765. In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be administered in combination with GDC-0980. In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be administered in combination with anti-BEZ235 (also known as NVP-BEZ235). In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be administered in combination with BGT226. In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be administered in combination with GSK2126458. In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be administered in combination with PF-04691502. In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be administered in combination with anti-PF-05212384 (also known as PKI-587).

[0484] In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody can be administered in combination with a chemotherapeutic agent. A chemotherapeutic agent is a chemical compound used to treat cancer. Exemplary chemotherapeutic agents include, but are not limited to, erlotinib ( Genentech / OSIPharm.), anti-hormonal agents used to modulate or inhibit the effects of hormones on tumors (such as antiestrogens and selective estrogen receptor modulators (SERMs)), such as alemtuzumab (Campath), bevacizumab ( Genentech) antibodies; Cetuximab ( Imclone; Panitumumab ( Amgen), rituximab ( Genentech / Biogen Idec), Pertuzumab ( 2C4, Genentech) or trastuzumab ( Genentech), EGFR inhibitors (EGFR antagonists), tyrosine kinase inhibitors and chemotherapeutic agents, and also include nonsteroidal anti-inflammatory drugs (NSAIDs) with analgesic, antipyretic and anti-inflammatory effects.

[0485] In the case where the methods described herein involve combination therapy such as the specific combination therapy mentioned above, the combination therapy includes co-administration of the bispecific anti-FcRH5 / anti-CD3 antibody and one or more additional therapeutic agents, and such co-administration can be combined (wherein the two or more therapeutic agents are contained in the same or separate formulations) or separately, in which case the administration of the bispecific anti-FcRH5 / anti-CD3 antibody can occur before, simultaneously with, and / or after the administration of the one or more additional therapeutic agents. In one embodiment, the administration of the bispecific anti-FcRH5 / anti-CD3 antibody and the administration of the additional therapeutic agent or exposure to radiation therapy are performed within about one month, or within about one, two, three, four, five, or six days of each other.

[0486] In some aspects, the subject does not have an increased risk of CRS (e.g., does not experience Grade 3+ CRS during treatment with the bispecific antibody or CAR-T therapy; does not have detectable circulating plasma cells; and / or does not have extensive extramedullary disease).

[0487] F. Cancer

[0488] Any method of the present invention described herein can be used to treat cancer, such as B cell proliferative disorders (including multiple myeloma (MM), which can be relapsed or refractory (R / R) MM). In some aspects, the patient has received at least three previous treatment lines for B cell proliferative disorders (e.g., MM), for example, 4L+, for example, three, four, five, six or more than six previous treatment lines have been received. For example, the patient may have been exposed to proteasome inhibitors (P1), immunomodulatory drugs (IMiD), autologous stem cell transplantation (ASCT), anti-CD38 therapy (e.g., anti-CD38 antibody therapy, such as daratumumab therapy), CAR-T therapy or a therapy comprising a bispecific antibody. In some cases, the patient has been exposed to all three therapies of P1, IMiD and anti-CD38 therapy.Other examples of B-cell proliferative disorders / malignancies suitable for treatment with a bispecific anti-FcRH5 / anti-CD3 antibody (e.g., silvostomumab) according to the methods described herein include, but are not limited to, non-Hodgkin lymphoma (NHL) (including diffuse large B-cell lymphoma (DLBCL), which may be relapsed or refractory DLBCL) and other cancers including: germinal center B-cell-like (GCB) diffuse large B-cell lymphoma (DLBCL), activated B-cell-like (ABC) DLBCL, follicular lymphoma (FL), Mantle cell lymphoma (MCL), acute myeloid leukemia (AML), chronic lymphocytic leukemia (CLL), marginal zone lymphoma (MZL), small lymphocytic leukemia (SLL), lymphoplasmacytic lymphoma (LL), Waldenstrom's macroglobulinemia (WM), central nervous system lymphoma (CNSL), Burkitt's lymphoma (BL), precursor B-cell lymphocytic leukemia, splenic marginal zone lymphoma, hairy cell leukemia, splenic lymphoma / leukemia (unclassifiable), splenic diffuse red pulp small B-cell lymphoma, variant capillary cell leukemia leukemia, Waldenstrom's macroglobulinemia, heavy chain disease (alpha heavy chain disease, gamma heavy chain disease, mu heavy chain disease), plasma cell myeloma, solitary plasmacytoma of bone, extraosseous plasmacytoma, extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma), lymph node marginal zone lymphoma, pediatric lymph node marginal zone lymphoma, pediatric follicular lymphoma, primary cutaneous follicle center lymphoma, T cell / histiocyte-rich large B cell lymphoma, primary DLBCL of the CNS, primary cutaneous DLBCL (leg type), EBV positive in the elderly DLBCL, DLBCL associated with chronic inflammation, lymphomatoid granuloma, primary mediastinal (thymic) large B-cell lymphoma, intravascular large B-cell lymphoma, ALK-positive large B-cell lymphoma, plasmablastic lymphoma, large B-cell lymphoma due to HHV8-associated multicentric Castleman disease, primary effusion lymphoma: B-cell lymphoma (unclassifiable, with features intermediate between DLBCL and Burkitt lymphoma), and B-cell lymphoma (unclassifiable, with features intermediate between DLBCL and classical Hodgkin lymphoma). Another example of a B-cell proliferative disorder includes, but is not limited to, multiple myeloma (MM); low-grade / follicular NHL; small lymphocytic (SL) NHL; intermediate-grade / follicular NHL; intermediate-grade diffuse NHL; high-grade immunoblastic NHL; high-grade lymphoblastic NHL; high-grade small non-lytic cell NHL; bulky NHL; AIDS-related lymphoma; and acute lymphoblastic leukemia (ALL); chronic myeloid leukemia; and post-transplant lymphoproliferative disorder (PTLD). Another example of cancer includes, but is not limited to, carcinoma, lymphoma, blastoma, sarcoma, and leukemia or lymphoid malignancies, including B-cell lymphoma.More specific examples of such cancers include, but are not limited to: low-grade / follicular NHL; small lymphocytic (SL) NHL; intermediate-grade / follicular NHL; intermediate-grade diffuse NHL; high-grade immunoblastic NHL; high-grade lymphoblastic NHL; high-grade small non-truncated cell NHL; bulky disease NHL; AIDS-related lymphoma; and acute lymphoblastic leukemia (ALL); chronic myeloid leukemia; and post-transplant lymphoproliferative disorder (PTLD). Solid tumors that may be amenable to treatment with the bispecific anti-FcRH5 / anti-CD3 antibodies according to the methods described herein include squamous cell carcinoma (e.g., epithelial squamous cell carcinoma), lung cancer (including small cell lung cancer, non-small cell lung cancer, lung adenocarcinoma, and lung squamous cell carcinoma), peritoneal cancer, hepatocellular carcinoma, gastric cancer (including gastrointestinal cancer and gastrointestinal stromal cancer), pancreatic cancer, glioblastoma, cervical cancer, ovarian cancer, liver cancer, bladder cancer, urinary tract cancer, hepatoma, breast cancer, colon cancer, rectal cancer, colorectal cancer, endometrial cancer or uterine cancer, salivary gland cancer, kidney or renal cancer. Cancers suitable for treatment by the antibodies of the invention include breast cancer, colorectal cancer, rectal cancer, non-small cell lung cancer, glioblastoma, non-Hodgkin lymphoma (NHL), renal cell carcinoma, prostate cancer, liver cancer, pancreatic cancer, soft tissue sarcoma, Kaposi's sarcoma, carcinoid tumor, head and neck cancer, ovarian cancer and mesothelioma.

[0489] G. Previous anticancer therapy

[0490] In some aspects, the subject with the level of elevated T cell proliferation markers (e.g., MKI67) and / or the number of increased MKI67+ cells has previously been treated for B cell proliferative disorders (e.g., MM). In some aspects, the subject has received at least one, two, three, four, five, six, seven, eight, nine, ten, eleven, twelve, thirteen, fourteen, fifteen or more than fifteen treatment lines for B cell proliferative disorders, for example, 2L+, 3L+, 4L+, 5L+, 6L+, 7L+, 8L+, 9L+, 10L+, 11L+, 12L+, 13L+, 14L+ or 15L+. In some aspects, the subject has received at least three prior lines of treatment for a B-cell proliferative disorder (e.g., MM), e.g., is 4L+, e.g., has received three, four, five, six, seven, eight, nine, ten, eleven, twelve, thirteen, fourteen, fifteen or more than fifteen lines of treatment. In some aspects, the subject has relapsed or refractory (R / R) multiple myeloma (MM), e.g., has 4L+R / R MM.

[0491] In some aspects, the prior line of treatment includes one or more of the following: a proteasome inhibitor (PI), such as bortezomib, carfilzomib, or ixazomib; an immunomodulatory drug (IMiD), such as thalidomide, lenalidomide, or pomalidomide; an autologous stem cell transplant (ASCT); an anti-CD38 agent, such as daratumumab (U.S. Patent No. 7,829,673 and U.S. Publication No. 20160067205A1), "MOR202" (U.S. Patent No. 8,263,746), isatuximab (SAR-650984); CAR-T therapy; therapy comprising bispecific antibodies; anti-SLAMF7 therapeutic agents (e.g., anti-SLAMF7 antibodies, such as elotuzumab); nuclear export inhibitors (e.g., selinexor); and histone deacetylase (HDAC) inhibitors (e.g., panobinostat). In some aspects, the previous line of treatment includes an antibody-drug conjugate (ADC). In some aspects, the previous line of treatment includes a B cell maturation antigen (BCMA) directed therapy, such as an antibody-drug conjugate (BCMA-ADC) targeting BCMA.

[0492] In some aspects, the prior line of treatment includes all three of a proteasome inhibitor (PI), an IMiD, and an anti-CD38 agent (eg, daratumumab).

[0493] In some aspects, B cell proliferative disorders (e.g., MM) are refractory to the treatment line, for example, daratumumab, PI, IMiD, ASCT, anti-CD38 agents, CAR-T therapy, therapy comprising bispecific antibodies, anti-SLAMF7 therapeutic agents, nuclear export inhibitors, HDAC inhibitors, ADC or BCMA directed therapy One or more is refractory. In some aspects, B cell proliferative disorders (e.g., MM) are refractory to daratumumab.

[0494] H. Risk-Benefit Profile

[0495] Treatment with a bispecific anti-FcRH5 / anti-CD3 antibody (e.g., silvostomumab), the methods described herein can result in an improved benefit-risk profile for patients with cancer (e.g., multiple myeloma (MM), e.g., relapsed or refractory (R / R) MM), e.g., 4L+R / R MM). In some cases, treatment with the methods described herein that result in administration of a bispecific anti-FcRH5 / anti-CD3 antibody in the context of a fractionated, dose-escalating dosing regimen can result in an improvement in the risk of undesirable events such as cytokine-driven toxicities (e.g., cytokine release syndrome (CRS)), infusion-related reactions (IRR), macrophage activation syndrome (MAS), neurological toxicity, severe tumors, and / or leukemia following treatment with a bispecific anti-FcRH5 / anti-CD3 antibody using a fractionated, dose-escalating dosing regimen of the invention relative to treatment with a bispecific anti-FcRH5 / anti-CD3 antibody using a non-fractionated dosing regimen. In some embodiments, the patient's tumor lysis syndrome (TLS), neutropenia, thrombocytopenia, liver enzyme elevation, and / or central nervous system (CNS) toxicity are reduced (e.g., 20% or greater, 25% or greater, 30% or greater, 35% or greater, 40% or greater, 45% or greater, 50% or greater, 55% or greater, 60% or greater, 65% or greater, 70% or greater, 75% or greater, 80% or greater, 85% or greater, 90% or greater, 95% or greater, 96% or greater, 97% or greater, 98% or greater, or 99% or greater) or completely inhibited (100% reduction).

[0496] I. Safety and effectiveness

[0497] i. Security

[0498] In some aspects, less than 15% (e.g., less than 14%, less than 13%, less than 12%, less than 11%, less than 10%, less than 9%, less than 8%, less than 7%, less than 6%, less than 5%, less than 4%, less than 3%, less than 2%, or less than 1%) of patients treated with the methods described herein experience Grade 3 or 4 cytokine release syndrome (CRS). In some aspects, less than 5% of patients treated with the methods described herein experience Grade 3 or 4 CRS.

[0499] In some aspects, less than 10% (e.g., less than 9%, less than 8%, less than 7%, less than 6%, less than 5%, less than 4%, less than 3%, less than 2%, or less than 1%) of patients treated with the methods described herein experience 4+ grade CRS. In some aspects, less than 3% of patients treated with the methods described herein experience 4+ grade CRS. In some aspects, no patient experiences 4+ grade CRS.

[0500] In some aspects, less than 10% (e.g., less than 9%, less than 8%, less than 7%, less than 6%, less than 5%, less than 4%, less than 3%, less than 2%, or less than 1%) of patients treated with the methods described herein experience Grade 3 CRS. In some aspects, less than 5% of patients treated with the methods described herein experience Grade 3 CRS. In some aspects, no patient experiences Grade 3 CRS.

[0501] In some aspects, a Grade 2+ CRS event occurs only in the first treatment cycle. In some aspects, a Grade 2 CRS event occurs only in the first treatment cycle. In some aspects, no Grade 2 CRS event occurs.

[0502] In some aspects, less than 3% of patients treated using the methods described herein experience Grade 4+ CRS, less than 5% of patients treated using the methods described herein experience Grade 3 CRS, and Grade 2+ CRS events occur only in the first treatment cycle.

[0503] In some aspects, no Grade 3+ CRS events occurred, and Grade 2 CRS events occurred only in the first treatment cycle.

[0504] In some aspects, symptoms of immune effector cell-associated neurotoxicity syndrome (ICANS) are limited to confusion, disorientation, and expressive aphasia and resolve with steroid treatment.

[0505] In some aspects, less than 10% (e.g., less than 9%, less than 8%, less than 7%, less than 6%, less than 5%, less than 4%, less than 3%, less than 2%, or less than 1%) of the patients treated using the methods described herein experience epileptic seizures or other grade 3+ neurological adverse events. In some aspects, less than 5% of the patients experience epileptic seizures or other grade 3+ neurological adverse events. In some aspects, no patient experiences epileptic seizures or other grade 3+ neurological adverse events.

[0506] In some aspects, all neurological symptoms are self-limited or resolve with steroid and / or tocilizumab therapy.

[0507] ii. Efficacy

[0508] In some aspects, the overall response rate (ORR) of patients treated using the methods described herein is at least 25%, for example, at least 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 99% or 100%. In some aspects, the ORR is at least 40%. In some aspects, the ORR is at least 45% (e.g., at least 45%, 45.5%, 46%, 46.5%, 47%, 47.5%, 48%, 48.5%, 49%, 49.5% or 50%), at least 55% or at least 65%. In some aspects, the ORR is at least 47.2%. In some aspects, the ORR is about 47.2%. In some aspects, the ORR is 75% or greater. In some aspects, at least 1% of patients (e.g., at least 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, 60%, 61%, 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69%, 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, In some aspects, the ORR is 40% to 50%, and 10% to 20% of the patients have a CR or VGPR. In some aspects, the ORR is at least 40%, and at least 20% of patients have a CR or VGPR.

[0509] In some aspects, the average duration of response (DoR) for patients treated using the methods described herein is at least two months, e.g., at least three months, at least four months, at least five months, at least six months, at least seven months, at least eight months, at least nine months, at least ten months, at least eleven months, at least one year, or more than one year. In some aspects, the average DoR is at least four months. In some aspects, the average DoR is at least five months. In some aspects, the average DoR is at least seven months.

[0510] In some aspects, the six-month progression-free survival (PFS) rate of the patient treated using the methods described herein is at least 10%, for example, at least 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 99% or 100%. In some aspects, the six-month PFS rate is at least 25%. In some aspects, the six-month PFS rate is at least 40%. In some aspects, the six-month PFS rate is at least 55%.

[0511] J. Method of application

[0512] The method may involve administering a bispecific anti-FcRH5 / anti-CD3 antibody (e.g., silvostomumab) (and / or any additional therapeutic agent) by any suitable means, including parenteral, intrapulmonary, and intranasal, and if local treatment is desired, including intralesional administration. Parenteral infusions include intravenous, subcutaneous, intramuscular, intraarterial, and intraperitoneal routes of administration. In some embodiments, the bispecific anti-FcRH5 / anti-CD3 antibody is administered by intravenous infusion. In other cases, the bispecific anti-FcRH5 / anti-CD3 antibody is administered subcutaneously.

[0513] In some cases, a bispecific anti-FcRH5 / anti-CD3 antibody administered by intravenous injection exhibits less toxic responses (ie, fewer adverse effects) in patients than the same bispecific anti-FcRH5 / anti-CD3 antibody administered by subcutaneous injection, or vice versa.

[0514] In some aspects, the bispecific anti-FcRH5 / anti-CD3 antibody is administered intravenously over 4 hours (±15 minutes), eg, the first dose of the antibody is administered over 4 hours ±15 minutes.

[0515] In some aspects, the first and second doses of the antibody are administered intravenously with a median infusion time of less than four hours (e.g., less than three hours, less than two hours, or less than one hour), and the additional doses of the antibody are administered intravenously with a median infusion time of less than 120 minutes (e.g., less than 90 minutes, less than 60 minutes, or less than 30 minutes).

[0516] In some aspects, the first and second doses of the antibody are administered intravenously with a median infusion time of less than three hours, and the additional dose of the antibody is administered intravenously with a median infusion time of less than 90 minutes.

[0517] In some aspects, the first and second doses of the antibody are administered intravenously with a median infusion time of less than three hours, and the additional doses of the antibody are administered intravenously with a median infusion time of less than 60 minutes. In some aspects, the patient is hospitalized (e.g., hospitalized for 72 hours, 48 ​​hours, 24 hours, or less than 24 hours) during one or more administrations of the anti-FcRH5 / anti-CD3 antibody, such as for C1D1 (cycle 1, dose 1) or C1D1 and C1D2 (cycle 1, dose 2). In some aspects, the patient is hospitalized for 72 hours after the administration of C1D1 and C1D2. In some aspects, the patient is hospitalized for 24 hours after the administration of C1D1 and C1D2. In some aspects, the patient is not hospitalized after any dose of the anti-FcRH5 / anti-CD3 antibody is administered.

[0518] For all methods described herein, the bispecific anti-FcRH5 / anti-CD3 antibodies will be formulated, dosed, and administered in a manner consistent with good medical practice. Factors to be considered in this context include the specific disorder being treated, the specific mammal being treated, the clinical condition of the individual patient, the cause of the disorder, the site of delivery of the agent, the method of administration, the timing of administration, and other factors known to practitioners. The bispecific anti-FcRH5 / anti-CD3 antibodies need not be, but are optionally, formulated with one or more agents currently used to prevent or treat the disease in question. The effective amount of such other agents depends on the amount of bispecific anti-FcRH5 / anti-CD3 antibodies present in the formulation, the type of disease or treatment, and the other factors described above. The bispecific anti-FcRH5 / anti-CD3 antibodies may be appropriately administered to a patient over a series of treatments.

[0519] K. Bispecific anti-FcRH5 / anti-CD3 antibody

[0520] The methods described herein include administering a bispecific antibody that binds to FcRH5 and CD3 (i.e., a bispecific anti-FcRH5 / anti-CD3 antibody) to a subject with cancer (e.g., multiple myeloma, e.g., R / R multiple myeloma). In some cases, the subject has increased levels of a T cell proliferation marker (e.g., MKI67) and / or increased numbers of MKI67+ cells.

[0521] In some cases, any of the methods described herein may comprise administering a bispecific antibody comprising an anti-FcRH5 arm having a first binding domain comprising at least one, two, three, four, five or six hypervariable regions (HVRs) selected from: (a) HVR-H1 comprising the amino acid sequence of RFGVH (SEQ ID NO: 1); (b) HVR-H2 comprising the amino acid sequence of VIWRGGSTDYNAAFVS (SEQ ID NO: 2); (c) HVR-H3 comprising the amino acid sequence of HYYGSSDYALDN (SEQ ID NO: 3); (d) HVR-L1 comprising the amino acid sequence of KASQDVRNLVV (SEQ ID NO: 4); (e) HVR-L2 comprising the amino acid sequence of SGSYRYS (SEQ ID NO: 5); and (f) HVR-L3 comprising the amino acid sequence of QQHYSPPYT (SEQ ID NO: 6). In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody comprises: at least one (e.g., 1, 2, 3, or 4) of the heavy chain framework regions FR-H1, FR-H2, FR-H3, and FR-H4 comprising the sequences of SEQ ID NOs: 17 to 20, respectively; and / or at least one (e.g., 1, 2, 3, or 4) of the light chain framework regions FR-L1, FR-L2, FR-L3, and FR-L4 comprising the sequences of SEQ ID NOs: 21 to 24, respectively.

[0522] In some cases, any of the methods described herein may include administering a bispecific antibody comprising an anti-FcRH5 arm having a first binding domain comprising the following six HVRs: (a) HVR-H1 comprising the amino acid sequence of RFGVH (SEQ ID NO: 1); (b) HVR-H2 comprising the amino acid sequence of VIWRGGSTDYNAAFVS (SEQ ID NO: 2); (c) HVR-H3 comprising the amino acid sequence of HYYGSSDYALDN (SEQ ID NO: 3); (d) HVR-L1 comprising the amino acid sequence of KASQDVRNLVV (SEQ ID NO: 4); (e) HVR-L2 comprising the amino acid sequence of SGSYRYS (SEQ ID NO: 5); and (f) HVR-L3 comprising the amino acid sequence of QQHYSPPYT (SEQ ID NO: 6). In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody comprises: at least one (e.g., 1, 2, 3, or 4) of the heavy chain framework regions FR-H1, FR-H2, FR-H3, and FR-H4 comprising the sequences of SEQ ID NOs: 17 to 20, respectively; and / or at least one (e.g., 1, 2, 3, or 4) of the light chain framework regions FR-L1, FR-L2, FR-L3, and FR-L4 comprising the sequences of SEQ ID NOs: 21 to 24, respectively.

[0523] In some cases, the bispecific antibody comprises: an anti-FcRH5 arm comprising a first binding domain comprising: (a) a heavy chain variable (VH) domain comprising an amino acid sequence having at least 90% sequence identity (e.g., at least 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity) to, or the sequence of SEQ ID NO:7; (b) a light chain variable (VL) domain comprising an amino acid sequence having at least 90% sequence identity (e.g., at least 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity) to, or the sequence of SEQ ID NO:8; or (c) a VH domain as described in (a) and a VL domain as described in (b). Thus, in some cases, the first binding domain comprises: a VH domain comprising the amino acid sequence of SEQ ID NO:7; and a VL domain comprising the amino acid sequence of SEQ ID NO:8.

[0524] In some cases, any of the methods described herein may comprise administering a bispecific anti-FcRH5 / anti-CD3 antibody comprising an anti-CD3 arm having a second binding domain comprising at least one, two, three, four, five or six HVRs selected from: (a) HVR-H1 comprising the amino acid sequence of SYYIH (SEQ ID NO:9); (b) HVR-H2 comprising the amino acid sequence of WIYPENDNTKYNEKFKD (SEQ ID NO:10); (c) HVR-H3 comprising the amino acid sequence of DGYSRYYFDY (SEQ ID NO:11); (d) HVR-L1 comprising the amino acid sequence of KSSQSLLNSRTRKNYLA (SEQ ID NO:12); (e) HVR-L2 comprising the amino acid sequence of WTSTRKS (SEQ ID NO:13); and (f) HVR-L3 comprising the amino acid sequence of KQSFILRT (SEQ ID NO:14). In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody comprises: at least one (e.g., 1, 2, 3, or 4) of the heavy chain framework regions FR-H1, FR-H2, FR-H3, and FR-H4 comprising the sequences of SEQ ID NOs: 25 to 28, respectively; and / or at least one (e.g., 1, 2, 3, or 4) of the light chain framework regions FR-L1, FR-L2, FR-L3, and FR-L4 comprising the sequences of SEQ ID NOs: 29 to 32, respectively.

[0525] In some cases, any of the methods described herein may include administering a bispecific anti-FcRH5 / anti-CD3 antibody comprising an anti-CD3 arm having a second binding domain comprising the following six HVRs: (a) HVR-H1 comprising the amino acid sequence of SYYIH (SEQ ID NO:9); (b) HVR-H2 comprising the amino acid sequence of WIYPENDNTKYNEKFKD (SEQ ID NO:10); (c) HVR-H3 comprising the amino acid sequence of DGYSRYYFDY (SEQ ID NO:11); (d) HVR-L1 comprising the amino acid sequence of KSSQSLLNSRTRKNYLA (SEQ ID NO:12), (e) HVR-L2 comprising the amino acid sequence of WTSTRKS (SEQ ID NO:13); and (f) HVR-L3 comprising the amino acid sequence of KQSFILRT (SEQ ID NO:14). In some cases, the bispecific anti-FcRH5 / anti-CD3 antibody comprises: at least one (e.g., 1, 2, 3, or 4) of the heavy chain framework regions FR-H1, FR-H2, FR-H3, and FR-H4 comprising the sequences of SEQ ID NOs: 25 to 28, respectively; and / or at least one (e.g., 1, 2, 3, or 4) of the light chain framework regions FR-L1, FR-L2, FR-L3, and FR-L4 comprising the sequences of SEQ ID NOs: 29 to 32, respectively.

[0526] In some cases, the bispecific antibody comprises: an anti-CD3 arm comprising a second binding domain comprising: (a) a VH domain comprising an amino acid sequence having at least 90% sequence identity (e.g., at least 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity) to, or the sequence of SEQ ID NO: 15; (b) a VL domain comprising an amino acid sequence having at least 90% sequence identity (e.g., at least 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity) to, or the sequence of SEQ ID NO: 16; or (c) a VH domain as in (a) and a VL domain as in (b). Thus, in some cases, the second binding domain comprises: a VH domain comprising the amino acid sequence of SEQ ID NO:15; and a VL domain comprising the amino acid sequence of SEQ ID NO:16.

[0527] In some cases, any of the methods described herein may include administering a bispecific antibody comprising: (1) an anti-FcRH5 arm having a first binding domain comprising at least one, two, three, four, five, or six HVRs selected from: (a) HVR-H1 comprising the amino acid sequence of RFGVH (SEQ ID NO: 1); (b) HVR-H2 comprising the amino acid sequence of VIWRGGSTDYNAAFVS (SEQ ID NO: 2); (c) HVR-H3 comprising the amino acid sequence of HYYGSSDYALDN (SEQ ID NO: 3); (d) HVR-L1 comprising the amino acid sequence of KASQDVRNLVV (SEQ ID NO: 4); (e) HVR-L2 comprising the amino acid sequence of SGSYRYS (SEQ ID NO: 5); and (f) HVR-L3 comprising the amino acid sequence of QQHYSPPYT (SEQ ID NO: 6). NO:6); and (2) an anti-CD3 arm having a second binding domain, the second binding domain comprising at least one, two, three, four, five or six HVRs selected from the following: (a) HVR-H1, which comprises the amino acid sequence of SYYIH (SEQ ID NO:9); (b) HVR-H2, which comprises the amino acid sequence of WIYPENDNTKYNEKFKD (SEQ ID NO:10); (c) HVR-H3, which comprises the amino acid sequence of DGYSRYYFDY (SEQ ID NO:11); (d) HVR...

Claims

1. A method for treating a subject with multiple myeloma (MM) using a bispecific antibody that binds to Fc receptor homolog 5 (FcRH5) and cluster of differentiation 3 (CD3), the method include: (a) determining the level of a T cell proliferation marker in a biological sample obtained from the subject at a time point after administration of the bispecific antibody; (b) comparing the level of the T cell proliferation marker in the biological sample to a reference level, wherein the level of the T cell proliferation marker in the biological sample is increased relative to the reference level, identifying the subject as a subject responsive to the bispecific antibody; as well as (c) continuing to administer the bispecific antibody to the subject if the level of the T cell proliferation marker is increased relative to the reference level.

2. A method for treating a subject with MM using a bispecific antibody that binds to FcRH5 and CD3, the method include: (a) determining whether the proliferation marker Ki-67 is positive (MKI67) in a biological sample obtained from the subject at a time point after administration of the bispecific antibody + ) The number of T cells; (b) adding MKI67 in the biological sample + The number of T cells is compared to a reference number, wherein the MKI67 in the biological sample is greater than or equal to the reference number. + If the number of T cells increases, the subject is identified as a subject that responds to the bispecific antibody; as well as (c) if the MKI67 in the biological sample of the subject is greater than or equal to the reference amount, + If the number of T cells increases, then continue to administer the bispecific antibody to the subject.

3. A method for monitoring the response of a subject with MM to treatment with a bispecific antibody that binds to FcRH5 and CD3, the method comprising: include: (a) determining the level of a T cell proliferation marker in a biological sample obtained from the subject at a time point after administration of the bispecific antibody; as well as (b) comparing the level of the T cell proliferation marker in the biological sample to a reference level, wherein the level of the T cell proliferation marker in the biological sample is increased relative to the reference level, identifying the subject as a subject responsive to the bispecific antibody, The subject's response to treatment with the bispecific antibody is thereby monitored.

4. A method for monitoring the response of a subject with MM to treatment with a bispecific antibody that binds to FcRH5 and CD3, the method comprising: include: (a) determining the expression of MKI67 in a biological sample obtained from the subject at a time point after administration of the bispecific antibody + The number of T cells; as well as (b) adding MKI67 in the biological sample + The number of T cells is compared to a reference number, wherein the MKI67 in the biological sample is greater than or equal to the reference number. + If the number of T cells increases, the subject is identified as a subject that responds to the bispecific antibody, The subject's response to treatment with the bispecific antibody is thereby monitored.

5. A method for assessing the therapeutic response of a subject with MM to treatment with a bispecific antibody that binds to FcRH5 and CD3, the method comprising: include: (a) determining the level of a T cell proliferation marker in a biological sample obtained from the subject at a time point after administration of the bispecific antibody; as well as (b) maintaining, adjusting or stopping the treatment of the subject based on the comparison of the level of the T cell proliferation marker in the biological sample with a reference level, wherein a change in the level of the T cell proliferation marker in the biological sample compared to the reference level is indicative of a response to treatment with the bispecific antibody.

6. The method according to claim 5, in: (a) if the level of the T cell proliferation marker in the biological sample is increased relative to the reference level, the subject has responded to the treatment and the treatment is maintained; or (b) if said level of said T cell proliferation marker in said biological sample is the same or decreased relative to said reference level, said subject is not responding to said treatment and said treatment is adjusted or stopped.

7. A method for assessing the therapeutic response of a subject with MM to treatment with a bispecific antibody that binds to FcRH5 and CD3, the method comprising: include: (a) determining the expression of MKI67 in a biological sample obtained from the subject at a time point after administration of the bispecific antibody + The number of T cells; as well as (b) based on the MKI67 in the biological sample + T cells in the biological sample compared to a reference number, maintaining, adjusting or stopping the treatment of the subject, wherein the MKI67 in the biological sample is increased compared to the reference number. + A change in the number of T cells is indicative of a response to treatment with the bispecific antibody.

8. The method according to claim 7, in: (a) if MKI67 in the biological sample is greater than or equal to the reference amount, + If the number of cells increases, the subject is responding to the treatment and the treatment is maintained; or (b) if the amount of MKI67 in the biological sample is greater than or equal to the reference amount, + If the number of cells remains the same or decreases, the subject is not responding to the treatment and the treatment is adjusted or stopped.

9. The method according to any one of claims 3 to 8, wherein the method further comprises administering the bispecific antibody to the subject.

10. The method according to any one of claims 1 to 9, wherein the administration of the bispecific antibody is performed with a dosing regimen comprising: (a) a first dosing cycle, wherein the first dosing cycle comprises at least a first dose (C1D1) and a second dose (C1D2) of the bispecific antibody; and (b) a second dosing cycle, wherein the second dosing cycle comprises a single dose of the bispecific antibody (C2D1). The method of claim 10 , wherein the time point after administration of the bispecific antibody is before the C2D1.

12. The method according to claim 10 or 11, in: (a) the C1D1 is between about 0.5 mg and about 19.9 mg; (b) the C1D2 is between about 20 mg and about 600 mg; and (c) the C2D1 is between about 20 mg and about 600 mg.

13. The method according to any one of claims 10 to 12, in: (a) the C1D1 is between about 1.2 mg and about 10.8 mg; (b) the C1D2 is between about 80 mg and about 300 mg; and (c) the C2D1 is between about 80 mg and about 300 mg.

14. The method according to any one of claims 10 to 13, in: (a) the C1D1 is about 3.6 mg; (b) the C1D2 is about 198 mg; and (c) The C2D1 is about 198 mg.

15. The method according to any one of claims 10 to 14, wherein the length of the first dosing cycle and the second dosing cycle is 21 days.

16. The method of claim 15, wherein the dosing regimen comprises administering the C1D1 and the C1D2 to the subject on or about day 1 and day 8 of the first dosing cycle, respectively, and administering the C2D1 on or about day 1 of the second dosing cycle.

17. The method of any one of claims 10 to 16, wherein the dosing regimen comprises one or more additional dosing cycles.

18. The method of any one of claims 17, wherein the dosing regimen comprises administering the bispecific antibody to the subject on or about day 1 of each of the additional dosing cycles.

19. The method of claim 17 or 18, wherein the one or more additional administration cycles include: (a) a third dosing cycle, wherein the third dosing cycle comprises a single dose of the bispecific antibody (C3D1); and / or (b) a fourth dosing cycle, wherein the fourth dosing cycle comprises a single dose of the bispecific antibody (C4D1).

20. The method of claim 19, wherein the time point after administration of the bispecific antibody is before the C3D1 and / or the C4D1.

21. The method according to any one of claims 1 to 9, wherein the administration of the bispecific antibody is performed with a dosing regimen comprising: (a) a first dosing cycle, wherein the first dosing cycle comprises at least a first dose (C1D1), a second dose (C1D2), and a third dose (C1D3) of the bispecific antibody; and (b) a second dosing cycle, wherein the second dosing cycle comprises a single dose of the bispecific antibody (C2D1).

22. The method of claim 21, wherein the time point after administration of the bispecific antibody is before the C2D1.

23. The method according to claim 21 or 22, in: (a) the C1D1 is between about 0.01 mg and about 2.9 mg; (b) the C1D2 is between about 3 mg and about 19.9 mg; (c) the C1D3 is between about 20 mg and about 600 mg; and (d) the C2D1 is between about 20 mg and about 600 mg.

24. The method according to any one of claims 21 to 23, in: (a) the C1D1 is between about 0.2 mg and about 0.4 mg; (b) the C1D2 is between about 3.2 mg and about 10 mg; (c) the C1D3 is between about 80 mg and about 300 mg; and (d) the C2D1 is between about 80 mg and about 300 mg.

25. The method according to any one of claims 21 to 24, in: (a) the C1D1 is about 0.3 mg; (b) the C1D2 is about 3.6 mg; (c) the C1D3 is about 160 mg; and (d) The C2D1 is about 160 mg.

26. The method of any one of claims 21 to 25, wherein the first dosing cycle and the second dosing cycle are 21 days in length.

27. The method of claim 26, wherein the dosing regimen comprises administering the C1D1, the C1D2, and the C1D3 on or about day 1, day 8, and day 15 of the first dosing cycle, respectively, and administering the C2D1 on or about day 1 of the second dosing cycle.

28. The method of any one of claims 21 to 27, wherein the dosing regimen comprises one or more additional dosing cycles.

29. The method of any one of claims 28, wherein the dosing regimen comprises administering the bispecific antibody to the subject on or about day 1 of each of the additional dosing cycles.

30. The method of claim 28 or 29, wherein the one or more additional administration cycles include: (a) a third dosing cycle, wherein the third dosing cycle comprises a single dose of the bispecific antibody (C3D1); and / or (b) a fourth dosing cycle, wherein the fourth dosing cycle comprises a single dose of the bispecific antibody (C4D1).

31. The method of claim 30, wherein the time point after administration of the bispecific antibody is before the C3D1 and / or the C4D1.

32. The method of any one of claims 1, 3, 5, 6, and 9 to 31, wherein the T cell proliferation marker is the proliferation marker Ki-67 (MKI67).

33. The method of any one of claims 1, 3, 5, 6, and 9 to 32, wherein the level of the T cell proliferation marker is a protein level.

34. The method of claim 33, wherein the protein level is detected by flow cytometry (FC), Western blot, enzyme-linked immunosorbent assay (ELISA), mass spectrometry (MS), immunofluorescence (IF), or immunohistochemistry (IHC).

35. The method of claim 33 or 34, wherein the protein level is detected using an MKI67 antibody.

36. The method of claim 35, wherein the MKI67 antibody is a monoclonal Ki-67 or MIB-1 antibody.

37. The method of any one of claims 1, 3, 5, 6, and 9 to 32, wherein the level of the T cell proliferation marker is the mRNA level of MKI67.

38. The method of claim 37, wherein the mRNA level is detected by polymerase chain reaction (PCR), reverse transcription-PCR (RT-PCR), quantitative-PCR (qPCR), microarray analysis, Northern blot, or RNA sequencing.

39. The method of any one of claims 1, 3, 5, 6, and 9 to 38, wherein the T cell proliferation marker is detected in T cells.

40. The method of claim 39, wherein the T cells are MKI67 + .

41. The method of any one of claims 1, 3, 5, 6, and 9 to 40, wherein the reference level is the level of the T cell proliferation marker determined in a biological sample obtained from the subject prior to administering the bispecific antibody to the subject.

42. The method of any one of claims 1, 3, 5, 6, and 9 to 41, wherein the reference level is the level of MKI67 determined in a biological sample obtained from the subject prior to administering the bispecific antibody to the subject.

43. The method of any one of claims 2, 4, and 7 to 42, wherein the MKI67+ T cells are detected by FC, Western blot, ELISA, MS, IF, or IHC.

44. The method according to any one of claims 2, 4 and 7 to 43, wherein the MKI67 + T cells were detected using MKI67 antibody.

45. The method of claim 44, wherein the MKI67 antibody is a monoclonal Ki-67 or MIB-1 antibody.

46. ​​The method according to any one of claims 2, 4 and 7 to 45, wherein the reference amount is MKI67 determined in a biological sample obtained from the subject before administering the bispecific antibody to the subject. + Said number of T cells.

47. The method of any one of claims 2, 4, and 7 to 46, wherein the T cells are cluster of differentiation 8 (CD8) positive (CD8 + ).

48. The method of any one of claims 2, 4, and 7 to 47, wherein the T cells are granzyme B (Gzb) positive (Gzb+).

49. The method of any one of claims 1 to 48, wherein the biological sample is blood, serum or plasma.

50. The method of any one of claims 1 to 49, wherein the bispecific antibody comprises: an anti-FcRH5 arm comprising a first binding domain comprising the following six hypervariable regions (HVRs): (a) HVR-H1 comprising the amino acid sequence of RFGVH (SEQ ID NO: 1); (b) HVR-H2 comprising the amino acid sequence of VIWRGGSTDYNAAFVS (SEQ ID NO: 2); (c) HVR-H3 comprising the amino acid sequence of HYYGSSDYALDN (SEQ ID NO: 3); (d) HVR-L1 comprising the amino acid sequence of KASQDVRNLVV (SEQ ID NO: 4); (e) HVR-L2 comprising the amino acid sequence of SGSYRYS (SEQ ID NO:5); and (f) HVR-L3 comprising the amino acid sequence of QQHYSPPYT (SEQ ID NO: 6).

51. The method of any one of claims 1 to 50, wherein the bispecific antibody comprises: an anti-FcRH5 arm comprising a first binding domain comprising: (a) a heavy chain variable (VH) domain comprising an amino acid sequence having at least 95% sequence identity to the amino acid sequence of SEQ ID NO:7; (b) a light chain variable (VL) domain comprising an amino acid sequence having at least 95% sequence identity to the amino acid sequence of SEQ ID NO:8; or (c) a VH domain as in (a) and a VL domain as in (b).

52. The method of claim 51, wherein the first binding domain comprises: a VH domain comprising the amino acid sequence of SEQ ID NO:7; and a VL domain comprising the amino acid sequence of SEQ ID NO:

8.

53. The method of any one of claims 1 to 52, wherein the bispecific antibody comprises: an anti-CD3 arm comprising a second binding domain comprising the following six HVRs: (a) HVR-H1 comprising the amino acid sequence of SYYIH (SEQ ID NO: 9); (b) HVR-H2 comprising the amino acid sequence of WIYPENDNTKYNEKFKD (SEQ ID NO: 10); (c) HVR-H3 comprising the amino acid sequence of DGYSRYYFDY (SEQ ID NO: 11); (d) HVR-L1 comprising the amino acid sequence of KSSQSLLNSRTRKNYLA (SEQ ID NO: 12); (e) HVR-L2 comprising the amino acid sequence of WTSTRKS (SEQ ID NO: 13); and (f) HVR-L3 comprising the amino acid sequence of KQSFILRT (SEQ ID NO: 14).

54. The method of any one of claims 1 to 53, wherein the bispecific antibody comprises: an anti-CD3 arm comprising a second binding domain, the second binding domain comprising: (a) a VH domain comprising an amino acid sequence having at least 95% sequence identity with the amino acid sequence of SEQ ID NO: 15; (b) a VL domain comprising an amino acid sequence having at least 95% sequence identity with the amino acid sequence of SEQ ID NO: 16; or (c) a VH domain as in (a) and a VL domain as in (b).

55. The method of claim 54, wherein the second binding domain comprises: a VH domain comprising the amino acid sequence of SEQ ID NO: 15; and a VL domain comprising the amino acid sequence of SEQ ID NO:

16.

56. The method of any one of claims 1 to 55, wherein the bispecific antibody comprises: an anti-FcRH5 arm comprising a heavy chain polypeptide (H1) and a light chain polypeptide (L1); and an anti-CD3 arm comprising a heavy chain polypeptide (H2) and a light chain polypeptide (L2), and in: (a) H1 comprises the amino acid sequence of SEQ ID NO: 35; (b) L1 comprises the amino acid sequence of SEQ ID NO: 36; (c) H2 comprises the amino acid sequence of SEQ ID NO:37; and (d) L2 comprises the amino acid sequence of SEQ ID NO:

38.

57. The method of any one of claims 1 to 56, wherein the bispecific antibody comprises an aglycosylation site mutation.

58. The method of claim 57, wherein the aglycosylation site mutation reduces the effector function of the bispecific antibody.

59. The method of claim 57 or 58, wherein the deglycosylation site mutation is a substitution mutation.

60. The method of claim 59, wherein the bispecific antibody comprises a substitution mutation in the Fc region that reduces effector function.

61. The method of any one of claims 1 to 60, wherein the bispecific antibody is a monoclonal antibody.

62. The method of any one of claims 1 to 61, wherein the bispecific antibody is a humanized antibody.

63. The method of any one of claims 1 to 55 and 57 to 62, wherein the bispecific antibody is a chimeric antibody.

64. The method of any one of claims 1 to 55 and 57 to 63, wherein the bispecific antibody is an antibody fragment that binds FcRH5 and CD3.

65. The method of claim 64, wherein the antibody fragment is selected from the group consisting of: Fab, Fab'-SH, Fv, scFv and (Fab') 2 Fragment.

66. The method of any one of claims 1 to 63, wherein the bispecific antibody is a full-length antibody.

67. The method of any one of claims 1 to 63 and 66, wherein the bispecific antibody is an IgG antibody.

68. The method of claim 67, wherein the IgG antibody is IgG 1 Antibody.

69. The method according to any one of claims 1 to 55 and 57 to 68, wherein the bispecific antibody comprises one or more heavy chain constant domains, wherein the one or more heavy chain constant domains are selected from a first CH1 (CH1 1 ) domain, the first CH2 (CH2 1 ) domain, the first CH3 (CH3 1 ) domain, the second CH1 (CH1 2 ) domain, the second CH2 (CH2 2 ) domain and the second CH3 (CH3 2 ) domain.

70. The method of claim 69, wherein at least one of the one or more heavy chain constant domains is paired with another heavy chain constant domain.

71. The method according to claim 69 or 70, wherein the CH3 1 Domain and the CH3 2 The domains each comprise a protrusion or a cavity, and wherein the CH3 1 The protrusion or the cavity in the domain can be located in the CH3 2 In the cavity or the protrusion in the structural domain.

72. The method of claim 71, wherein the CH3 1 Domain and the CH3 2 The domains meet at the interface between the protrusion and the cavity.

73. The method according to any one of claims 69 to 72, wherein the CH2 1 Domain and the CH2 2 The domains each comprise a protrusion or a cavity, and wherein the CH2 1 The protrusion or the cavity in the domain can be located in the CH2 2 In the cavity or the protrusion in the structural domain.

74. The method of claim 73, wherein the CH2 1 Domain and the CH2 2 The domains meet at the interface between the protrusion and the cavity.

75. The method of claim 72, wherein the anti-FcRH5 arm comprises the protrusion and the anti-CD3 arm comprises the cavity.

76. The method of claim 75, wherein the CH3 domain of the anti-FcRH5 arm comprises a protrusion comprising a T366W amino acid substitution mutation (EU numbering), and the CH3 domain of the anti-CD3 arm comprises a cavity comprising T366S, L368A and Y407V amino acid substitution mutations (EU numbering).

77. The method of any one of claims 1 to 76, wherein the bispecific antibody is administered to the subject as a monotherapy.

78. The method of any one of claims 1 to 76, wherein the bispecific antibody is administered to the subject as a combination therapy.

79. The method of claim 78, wherein the bispecific antibody is administered to the subject simultaneously with one or more additional therapeutic agents.

80. The method of claim 78, wherein the bispecific antibody is administered to the subject prior to administration of one or more additional therapeutic agents.

81. The method of claim 78, wherein the bispecific antibody is administered to the subject after administration of one or more additional therapeutic agents.

82. The method of claim 81, wherein the one or more additional therapeutic agents comprises an effective amount of tocilizumab.

83. The method of claim 82, wherein tocilizumab is administered to the subject by intravenous infusion.

84. The method according to claim 82 or 83, in: (a) the subject weighs ≥100 kg, and tocilizumab is administered to the subject at a dose of 800 mg; (b) the subject weighs ≥30 kg and <100 kg, and tocilizumab is administered to the subject at a dose of 8 mg / kg; or (c) the subject weighs <30 kg, and tocilizumab is administered to the subject at a dose of 12 mg / kg.

85. The method of any one of claims 82 to 84, wherein tocilizumab is administered to the subject 2 hours prior to administration of the bispecific antibody.

86. The method of any one of claims 79 to 81, wherein the one or more additional therapeutic agents comprises an effective amount of an IMiD, daratumumab, or a B-cell maturation antigen (BCMA)-directed therapy.

87. The method of any one of claims 1 to 86, wherein the bispecific antibody is administered to the subject by intravenous infusion.

88. The method of any one of claims 1 to 86, wherein the bispecific antibody is administered subcutaneously to the subject.

89. The method of any one of claims 1 to 88, wherein the subject develops a cytokine release syndrome (CRS) event, and the method further comprises treating a symptom of the CRS event while suspending treatment with the bispecific antibody.

90. The method of claim 89, wherein the method further comprises administering to the subject an effective amount of tocilizumab to treat the CRS event.

91. The method of claim 90, wherein tocilizumab is administered intravenously to the subject in a single dose of about 8 mg / kg.

92. The method of claim 90 or 91, wherein the CRS event does not resolve or worsens within 24 hours of treating the symptoms of the CRS event, the method further comprising administering one or more additional doses of tocilizumab to the subject to manage the CRS event.

93. The method of claim 92, wherein the one or more additional doses of tocilizumab are administered intravenously to the subject at a dose of about 8 mg / kg.

94. The method of claim 81, wherein the one or more additional therapeutic agents comprises an effective amount of a corticosteroid.

95. The method of claim 94, wherein the corticosteroid is administered intravenously to the subject.

96. The method of claim 94 or 95, wherein the corticosteroid is methylprednisolone.

97. The method of claim 96, wherein methylprednisolone is administered at a dose of about 80 mg.

98. The method of claim 94 or 95, wherein the corticosteroid is dexamethasone.

99. The method of claim 98, wherein dexamethasone is administered at a dose of about 20 mg.

100. The method of any one of claims 81 and 94 to 99, wherein the one or more additional therapeutic agents comprises an effective amount of acetaminophen or paracetamol.

101. The method of claim 100, wherein acetaminophen or paracetamol is administered in a dose of between about 500 mg to about 1000 mg.

102. The method of claim 100 or 101, wherein acetaminophen or paracetamol is orally administered to the subject.

103. The method of any one of claims 81 and 94 to 102, wherein the one or more additional therapeutic agents comprises an effective amount of diphenhydramine.

104. The method of claim 103, wherein diphenhydramine is administered at a dose of between about 25 mg to about 50 mg.

105. The method of claim 103 or 104, wherein diphenhydramine is administered orally to the subject.

106. The method according to any one of claims 1 to 105, wherein the MM is relapsed or refractory (R / R) MM.

107. The method of claim 106, wherein the individual has received at least three prior lines of treatment for said MM.

108. The method of claim 107, wherein the individual has received at least four prior lines of treatment for the MM.

109. The method of any one of claims 106 to 108, wherein the individual has been exposed to a prior treatment comprising a proteasome inhibitor, an immunomodulatory drug (IMiD), and / or an anti-CD38 therapeutic.

110. The method of claim 109, wherein the proteasome inhibitor is bortezomib, carfilzomib, or ixazomib.

111. The method of claim 109, wherein the IMiD is thalidomide, lenalidomide, or pomalidomide.

112. The method of claim 109, wherein the anti-CD38 therapeutic agent is an anti-CD38 antibody.

113. The method of claim 112, wherein the anti-CD38 antibody is daratumumab, MOR202, or isatuximab.

114. The method of claim 113, wherein the anti-CD38 antibody is daratumumab.

115. The method of any one of claims 106 to 114, wherein the individual has been exposed to prior treatments comprising: anti-SLAMF7 therapeutics, nuclear export inhibitors, histone deacetylase (HDAC) inhibitors, autologous stem cell transplantation (ASCT), bispecific antibodies, antibody-drug conjugates (ADC), CAR-T cell therapy, or BCMA-directed therapy.

116. The method of claim 115, wherein the anti-SLAMF7 therapeutic agent is an anti-SLAMF7 antibody.

117. The method of claim 116, wherein the anti-SLAMF7 antibody is elotuzumab.

118. The method of claim 115, wherein the nuclear export inhibitor is selinexor.

119. The method of claim 115, wherein the HDAC inhibitor is panobinostat.

120. The method of claim 115, wherein the BCMA-directed therapy is an antibody-drug conjugate targeting BCMA.

121. A bispecific antibody that binds to FcRH5 and CD3 for use in the treatment of a subject with MM, the treatment include: (a) determining the level of a T cell proliferation marker in a biological sample obtained from the subject at a time point after administration of the bispecific antibody; (b) comparing the level of the T cell proliferation marker in the biological sample to a reference level, wherein the level of the T cell proliferation marker in the biological sample is increased relative to the reference level, identifying the subject as a subject responsive to the bispecific antibody; as well as (c) continuing to administer the bispecific antibody to the subject if the level of the T cell proliferation marker is increased relative to the reference level.

122. A bispecific antibody that binds to FcRH5 and CD3 for use in the treatment of a subject with MM, the treatment include: (a) determining whether the proliferation marker Ki-67 is positive (MKI67) in a biological sample obtained from the subject at a time point after administration of the bispecific antibody + ) The number of T cells; (b) adding MKI67 in the biological sample + The number of T cells is compared to a reference number, wherein the MKI67 in the biological sample is greater than or equal to the reference number. + If the number of T cells increases, the subject is identified as a subject that responds to the bispecific antibody; as well as (c) if the MKI67 in the biological sample of the subject is greater than or equal to the reference amount, + If the number of T cells increases, then continue to administer the bispecific antibody to the subject.

123. A bispecific antibody that binds to FcRH5 and CD3 for use in the treatment of a subject with MM, the treatment comprising the step of monitoring the subject's response to the treatment, the monitoring include: (a) determining the level of a T cell proliferation marker in a biological sample obtained from the subject at a time point after administration of the bispecific antibody; as well as (b) comparing the level of the T cell proliferation marker in the biological sample to a reference level, wherein the level of the T cell proliferation marker in the biological sample is increased relative to the reference level, identifying the subject as a subject responsive to the bispecific antibody, The subject's response to treatment with the bispecific antibody is thereby monitored.

124. A bispecific antibody that binds to FcRH5 and CD3 for use in the treatment of a subject with MM, said treatment comprising the step of monitoring the subject's response to the treatment, said monitoring include: (a) determining the expression of MKI67 in a biological sample obtained from the subject at a time point after administration of the bispecific antibody + The number of T cells; as well as (b) adding MKI67 in the biological sample + The number of T cells is compared to a reference number, wherein the MKI67 in the biological sample is greater than or equal to the reference number. + If the number of T cells increases, the subject is identified as a subject that responds to the bispecific antibody, The subject's response to treatment with the bispecific antibody is thereby monitored.

125. A bispecific antibody that binds to FcRH5 and CD3 for use in the treatment of a subject with MM, said treatment comprising the step of assessing the subject's response to the treatment. include: (a) determining the level of a T cell proliferation marker in a biological sample obtained from the subject at a time point after administration of the bispecific antibody; as well as (b) maintaining, adjusting or stopping the treatment of the subject based on the comparison of the level of the T cell proliferation marker in the biological sample with a reference level, wherein a change in the level of the T cell proliferation marker in the biological sample compared to the reference level is indicative of a response to treatment with the bispecific antibody.

126. A bispecific antibody that binds to FcRH5 and CD3 for use in the treatment of a subject with MM, said treatment comprising the step of assessing the subject's response to the treatment. include: (a) determining the expression of MKI67 in a biological sample obtained from the subject at a time point after administration of the bispecific antibody + The number of T cells; as well as (b) based on the MKI67 in the biological sample + T cells in the biological sample compared to a reference number, maintaining, adjusting or stopping the treatment of the subject, wherein the MKI67 in the biological sample is increased compared to the reference number. + A change in the number of T cells is indicative of a response to treatment with the bispecific antibody.

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