EA042623B1 - COMBINATION OF ANTIBODIES TO PD-1 AND BISPECIFIC ANTIBODIES TO CD20/CD3 FOR THE TREATMENT OF CANCER - Google Patents

Description

This application is filed on December 21, 2016 as an international patent application under the PCT and claims priority under U.S. Provisional Application No. 62/270749, filed on December 22, 2015, the disclosure of which is incorporated herein by reference in its entirety.

Sequence listing

This application includes a sequence listing in electronic format in the form of a .txt file called Sequence Listing, which was created on December 21, 2016, and which has a size of 13.7 kilobytes (kB). The contents of the Sequence Listing txt file are incorporated herein by reference.

Field of the Invention The present invention relates to methods of treating cancer comprising administering to a subject in need a therapeutically effective amount of an antibody that specifically binds to programmed cell death receptor-1 (PD-1), in combination with a bispecific antibody, which binds to CD20 and CD3.

Background Art of the Invention B-cell cancers are a group of heterogeneous leukocyte cancers known as B-lymphocytes and include forms of leukemia (located in the hematopoietic organs) and forms of lymphoma (located in the lymph nodes). B-cell forms of lymphoma include, without limitation, non-Hodgkin's lymphoma (NHL) and Hodgkin's lymphoma (HL). Forms of lymphoma are divided into sluggish (slowly growing) or aggressive forms of lymphoma. The most common indolent lymphoma is follicular lymphoma, and the most common aggressive lymphoma is diffuse large B-cell lymphoma. Forms of B-cell leukemia include, without limitation, acute lymphoblastic leukemia, hairy cell leukemia, and B-cell chronic lymphocytic leukemia.

In most cases of B-cell forms of a malignant tumor, CD20 is expressed on the cell surface of mature B-cells. Methods for treating cancer by targeting CD20 are known in the art. For example, the chimeric anti-CD20 monoclonal antibody rituximab has been used or proposed for use in the treatment of forms of cancer such as NHL, chronic lymphocytic leukemia (CLL) and small cell lymphoma (SLL), either as monotherapy, but more often in combination with chemotherapy. Although anti-CD20 antibody tumor targeting strategies have shown great promise in the clinical setting, not all patients have responded to anti-CD20 antibody therapy, and some patients have developed resistance or incomplete responses to anti-CD20 antibody therapy (eg, partial reduction number of peripheral B cells), the causes of which are not fully understood (but which, as a rule, rule out the loss of CD20 expression). Some patients have relapsed with a more aggressive phenotype or chemotherapy-resistant disease. Many patients with aggressive forms of lymphoma have a poor prognosis and a less than 50% chance of recurrence-free survival. The prognosis for patients who relapse or who are refractory to therapy remains poor, with median survival after salvage therapy ranging from 2 to 8 months. In addition, high-dose chemotherapy leads to the development of severe unwanted side effects. Thus, there is a high unmet need for therapeutics that are effective, prevent recurrence, and cause less significant side effects for patients with B-cell cancers.

Programmed cell death receptor-1 (PD-1) signaling in the tumor microenvironment plays a central role in enabling tumor cells to escape host immune surveillance. Clinical efficacy has been demonstrated to block the PD-1 signaling pathway in patients with a variety of tumor types, and antibody-based therapeutics that block PD-1 (eg, nivolumab and pembrolizumab) have been approved for the treatment of metastatic melanoma and metastatic squamous non-small cell disease. lung cancer. Recent evidence has demonstrated the clinical efficacy of blocking PD-1 in patients with aggressive NHL and Hodgkin's lymphoma (Lesokhin, et al 2014, abstract 291, 56th ASH Annual Meeting and Exposition, San Francisco, California, Ansell et al 2015, N. Engl. J. Med. 372(4):311-9).

CD3 is a homodimeric or heterodimeric antigen expressed on the surface of T cells in conjunction with a T cell receptor (TCR) complex and is essential for T cell activation. Anti-CD3 antibodies have been shown to cluster CD3 on the surface of T cells, thereby causing T cell activation in a manner analogous to TCR recruitment by peptide-loaded MHC molecules. Bispecific monoclonal antibodies designed to target both CD20 and CD3 combine CD20-expressing cells with cytotoxic T cells, resulting in CD20-targeted killing of polyclonal T cells.

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In view of the high unmet need for effective therapeutics for the treatment of B cell malignancies, it may be useful, as demonstrated herein, to combine treatment with an agent to enhance T cell function (e.g., a PD-1 inhibitor, such as an anti-PD- 1) together with an agent that binds to the target antigen (anti-CD20/CD3 bispecific antibody).

Brief summary of the present invention

In accordance with certain embodiments, the present invention relates to methods for treating, alleviating at least one symptom or sign, or inhibiting the growth of a cancer in a subject. Methods in accordance with this aspect of the present invention comprise administering to a subject in need thereof a therapeutically effective amount of an antibody, or an antigen-binding fragment thereof, that specifically binds to programmed cell death protein-1 (PD-1), in combination with a therapeutically effective amount of a bispecific antibody that specifically binds to CD20 and CD3.

According to certain embodiments of the present invention, methods are provided for treating, alleviating at least one symptom or sign, or inhibiting the growth of a cancer in a subject. According to certain embodiments of the present invention, methods are provided for slowing tumor growth or preventing tumor recurrence. Methods in accordance with this aspect of the present invention provide for sequential administration to a subject in need thereof of one or more doses of a therapeutically effective amount of an antibody or antigen-binding fragment thereof that specifically binds to PD-1, in combination with one or more doses of a therapeutically effective amount of a bispecific antibody that binds specifically to CD20 and CD3.

In certain embodiments, the cancer or tumor is a tumor or cancer of hematopoietic cells. In certain embodiments, the cancer or tumor is a B cell tumor. In certain embodiments, the B cell tumor is selected from the group consisting of Hodgkin's lymphoma, non-Hodgkin's lymphoma, follicular lymphoma, small lymphocytic lymphoma, lymphoplasmacytic lymphoma, marginal zone cell lymphoma, mantle zone cell lymphoma, diffuse large B cell lymphoma, B- cellular forms of lymphoma, lymphomatoid granulomatosis, Burkitt's lymphoma, acute lymph regional leukemia, hairy cell leukemia and B-cell chronic lymphocytic leukemia.

In certain embodiments, each dose of anti-PD-1 antibody is 0.1-20 mg/kg of the subject's body weight. In certain embodiments, each dose of anti-PD-1 antibody is 0.3, 1, or 3 mg/kg of the subject's body weight. In certain embodiments, each dose of anti-PD-1 antibody is 50-600 mg.

In certain embodiments, each dose of the anti-CD20 and CD3 bispecific antibody is 0.1-10 mg/kg of the subject's body weight. In certain embodiments, each dose of the bispecific antibody is 10-8000 micrograms.

In certain embodiments, each dose of anti-PD-1 antibody is 0.3, 1, 3, or 10 mg/kg of the subject's body weight, and each dose of the bispecific antibody is 10-3000 micrograms. In certain embodiments, each dose of anti-PD-1 antibody is 1, 3, or 10 mg/kg of the subject's body weight, and each dose of the bispecific antibody is 100, 300, 1000, or 3000 micrograms. In certain embodiments, each dose of anti-PD-1 antibody is 50-300 mg and each dose of the bispecific antibody is 100, 300, 1000, or 3000 micrograms.

In certain embodiments, the methods of the present invention comprise administering a therapeutically effective amount of an anti-PD-1 antibody prior to, simultaneously with, or subsequent to administration of a bispecific antibody that specifically binds to CD20 and CD3. In one embodiment, the methods of the present invention comprise administering an anti-PD-1 antibody prior to administering an anti-CD20/CD3 bispecific antibody.

In certain embodiments, the methods of the present invention comprise administering 0-50 therapeutic doses of each of an anti-PD-1 antibody and an anti-CD20 and CD3 bispecific antibody, where each dose is administered 0.5-12 weeks after the nearest prior dose. In certain embodiments, each dose of anti-PD-1 antibody is administered once a week, once every 2 weeks, or once every 4 weeks, and each dose of the bispecific antibody is administered once a week, once every 2 weeks, or once every 4 weeks. weeks. In one embodiment, each dose of anti-PD-1 antibody is administered once every 2 weeks and each dose of the bispecific antibody is administered once a week.

In certain embodiments, each dose of the bispecific antibody is administered (as a fractional dose) as more than 1 part, such as 2 or more parts, over a specified dosing period.

In certain embodiments, the anti-PD-1 antibody and the bispecific antibody are used in combination with a third therapeutic agent or therapy.

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In certain embodiments, the anti-PD-1 antibody or antigen-binding protein comprises a heavy chain variable region (HCVR) complementarity determining region (HCDR) comprising the amino acid sequence of SEQ ID NO: 1 and a light chain variable region (LCVR) light chain CDR. ) containing the amino acid sequence of SEQ ID NO: 2. One such type of antigen-binding protein that can be used in the context of the methods of the present invention is an antibody to PD-1, such as REGN2810.

In certain embodiments, the bispecific antibody that binds to CD20 and CD3 comprises: (i) a first antigen-binding arm comprising the heavy chain CDRs of (A-HCDR1, A-HCDR1 and A-HCDR3) HCVR (A-HCVR) SEQ ID NO: 11 and light chain CDRs (LCDR1, LCDR2 and LCDR3) LCVR SEQ ID NO: 12; and (ii) a second antigen-binding arm comprising the heavy chain CDRs (B-HCDR1, B-HCDR2 and B-HCDR3) of HCVR (B-HCVR) SEQ ID NO: 13 and the light chain CDRs (LCDR1, LCDR2 and LCDR3) of LCVR SEQ ID NO: 12.

In certain embodiments, the present invention relates to the use of an anti-PD-1 antibody or antigen-binding fragment thereof alone or in combination with an anti-CD20 and CD3 bispecific antibody in the manufacture of a medicament for the treatment or inhibition of cancer growth in a subject, including humans. In certain embodiments, the cancer is a B-cell cancer. In one embodiment, the cancer is non-Hodgkin's lymphoma. In one embodiment, the cancer is Hodgkin's lymphoma. In one embodiment, the cancer is acute lymphoblastic leukemia.

Other embodiments of the present invention will be apparent from a review of the following detailed description.

Brief description of the drawings.

In FIG. 1 shows the results of the in vivo efficacy of an anti-mouse PD-1 antibody alone and in combination with an anti-CD20/CD3 bispecific antibody against established B16_CD20+ tumors (described in Example 1 herein).

In FIG. 2 shows the results for mice randomized into cohorts based on tumor size (as described in Example 2 herein).

In FIG. 3 shows the results of in vivo efficacy of anti-mouse PD-1 antibody alone and in combination with an anti-CD20/CD3 bispecific antibody against established B16_CD20+ tumors (described in Example 2 herein).

In FIG. 4 shows a schematic representation of treatment groups and dose cohorts for patients with lymphoma (B-cell non-Hodgkin's lymphoma and Hodgkin's lymphoma) (described in Example 3 herein).

In FIG. 5 shows a schematic representation of treatment groups and dose cohorts for patients with acute lymphoblastic leukemia (described in Example 3 herein).

In FIG. 6 is a study flow chart for an anti-PD-1 antibody (REGN2810) treatment regimen as a single agent for patients with lymphoma (B-cell non-Hodgkin's lymphoma and Hodgkin's lymphoma) (described in Example 3 herein).

In FIG. 7 is a study flow diagram for a CD20/CD3 bispecific antibody (bsAb1) treatment regimen as a single agent for patients with acute lymphoblastic leukemia (described in Example 3 herein).

In FIG. 8 is a study flow diagram for a bsAb1+REGN2810 combination treatment regimen for patients with B-cell non-Hodgkin's lymphoma (described in Example 3 herein).

In FIG. 9 is a study flow diagram for a bsAb1+REGN2810 combination treatment regimen for patients with acute lymphoblastic leukemia (described in Example 3 herein).

Detailed disclosure of the present invention.

Before the present invention is described, it is to be understood that the present invention is not limited to the specific experimental methods and conditions described, as such methods and conditions may vary. It should also be understood that the terminology used herein is only intended to describe specific embodiments, and is not intended to be limiting, as the scope of the present invention will only be limited by the appended claims.

Unless otherwise indicated, all technical and scientific terms used herein have the same meaning as those commonly understood by one of ordinary skill in the art to which the present invention pertains. In the context of this document, the term approximately when applied to a specific specified numerical value means that the value may differ from the specified value by no more than 1%. For example, in the context of this document, the expression approximately 100 includes 99 and 101 and all values in between (eg, 99.1, 99.2, 99.3, 99.4, etc.).

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While any methods and materials similar or equivalent to those described herein may be used to practice the present invention, the methods and materials described herein are preferred. All publications cited herein are incorporated herein for description by reference in their entirety.

Methods for treating or inhibiting the growth of B-cell forms of cancer.

The present invention includes methods for treating, alleviating, or lessening the severity of at least one symptom or sign, or inhibiting the growth of a cancer in a subject. Methods in accordance with this aspect of the present invention comprise administering to a subject in need thereof a therapeutically effective amount of an antibody or antigen-binding fragment thereof that specifically binds PD-1, in combination with a therapeutically effective amount of an anti-c CD20 and CD3 bispecific antibody. In the context of this document, the terms treat, treatment, etc. means relief of symptoms, elimination of the causes of symptoms, either temporarily or permanently, arrest or inhibition of tumor growth, reduction in the number of tumor cells or tumor mass, promotion of tumor regression, reduction in size, necrosis and/or disappearance of the tumor, prevention of tumor recurrence and/or increasing the duration of the subject's survival.

As used herein, a subject in need means a human or non-human mammal who exhibits one or more symptoms or signs of cancer and/or has been diagnosed with cancer, including B-cell cancer, and is in need of treatment. her treatment. In many embodiments, the term subject can be used interchangeably with the term patient. For example, a human subject may be diagnosed with a primary or metastatic tumor and/or one or more symptoms or signs, including, without limitation, enlarged lymph node(s), enlarged abdomen, chest pain/pressure, loss weight of unknown etiology, fever, night sweats, constant fatigue, loss of appetite, enlarged spleen, itching. The term includes subjects with primary or advanced B-cell tumors. In specific embodiments, the expression includes human subjects having B cell malignancy, e.g., Hodgkin's lymphoma, non-Hodgkin's lymphoma, follicular lymphoma, small cell lymphocytic lymphoma, lymphoplasmacytic lymphoma, marginal zone cell lymphoma, mantle cell lymphoma, diffuse large B-cell lymphoma, B-cell forms of lymphoma, lymphomatoid granulomatosis, Burkitt's lymphoma, acute lymphoblastic leukemia, hairy cell leukemia, and B-cell chronic lymphocytic leukemia, and which need their treatment. In a further embodiment, the expression includes individuals with a pathologic subtype of B-cell cancer, as shown in Table 1. 3-5 in this document. In other specific embodiments, the expression includes subjects with CD20+ tumors (eg, a tumor that expresses CD20 as determined by flow cytometry by >20% leukemic lymphoblast content). In certain embodiments, the term in need thereof includes patients with B-cell cancer that is resistant or refractory to previous therapy (eg, treatment with a traditional anticancer agent), or has not achieved satisfactory control with its use. For example, the expression includes subjects who have been treated with a CD20 inhibitor (eg, rituximab), chemotherapy, or an immunomodulatory agent such as a CTLA, IBB, LAG3, or OX-40 blocker. The term also includes subjects with B cell cancer for whom conventional anticancer therapy is not feasible, for example due to side effects in the form of toxicity. For example, the expression includes patients who received one or more courses of chemotherapy with side effects of toxicity. In certain embodiments, the term in need thereof includes patients with B cell cancer who have been treated but have subsequently relapsed or metastasized. For example, patients with B-cell cancer who may have been treated with one or more anticancer agents that cause tumor regression, but who subsequently experience recurrence of one or more anticancer drug-resistant cancer (eg, chemotherapy-resistant cancer ) are treated using the methods of the present invention.

The expression "subject in need" also includes subjects at risk of developing B-cell malignancy, for example, individuals with a family history of lymphoma, individuals with a history of Epstein-Barr virus infections such as infectious mononucleosis, or individuals with weakened immune systems due to HIV infection. or the use of immunosuppressive drugs.

In certain embodiments, the methods of the present invention can

- 4 042623 to be used to treat patients who have elevated levels of one or more cancer-associated biomarkers (e.g., programmed cell death protein ligand-1 (PD-L1), CD20, beta-2-microglobulin, lactate dehydrogenase, BCR fusion gene -ABL, rearrangement of the ALK gene). For example, the methods of the present invention provide for administering to a patient with elevated PD-L1 and/or CD20 a therapeutically effective amount of an anti-PD-1 antibody in combination with an anti-CD20/CD3 bispecific antibody.

In certain embodiments, the methods of the present invention are used in a subject with a B-cell cancer. The terms tumor, cancer, and cancer are used interchangeably herein. The term B-cell carcinoma as used herein refers to tumors of white blood cells known as B-lymphocytes and includes forms of leukemia (located in the hematopoietic organs) and forms of lymphoma (located in the lymph nodes). The present invention includes methods for treating both forms of leukemia and forms of lymphoma. In certain embodiments, B cell cancer includes, without limitation, Hodgkin's lymphoma, non-Hodgkin's lymphoma, follicular lymphoma, small lymphocytic lymphoma, lymphoplasmacytic lymphoma, marginal zone cell lymphoma, mantle zone cell lymphoma, diffuse large B cell lymphoma, B cell forms lymphomas, lymphomatoid granulomatosis, Burkitt's lymphoma, acute lymphoblastic leukemia, hairy cell leukemia, B-cell chronic lymphocytic leukemia, as well as pathological subtypes presented in Table. 3-5 in this document. B-cell forms of lymphoma are generally divided into high-grade and low-grade, typically referring to indolent (slow-growing) lymphoma and aggressive lymphoma, respectively. The present invention includes methods for treating both indolent and aggressive forms of lymphoma.

In accordance with certain embodiments, the present invention includes methods for treating or delaying or inhibiting tumor growth. In certain embodiments, the present invention includes methods for promoting tumor regression. In certain embodiments, the present invention includes methods for reducing the number of tumor cells or reducing tumor mass. In certain embodiments, the present invention includes methods for preventing tumor recurrence. Methods in accordance with this aspect of the present invention provide for the sequential administration to a subject in need thereof of a therapeutically effective amount of an anti-PD-1 antibody in combination with an anti-CD20/CD3 bispecific antibody, wherein each antibody is administered to the subject in multiple doses, e.g., as part of a particular dosing regimen. within the framework of therapy. For example, a dosage regimen for therapy may include administering one or more doses of anti-PD-1 antibody to a subject at a frequency of approximately once a day, once every two days, once every three days, once every four days, once every five days, once every six days, once a week, once every two weeks, once every three weeks, once every four weeks, once a month, once every two months, once every three months, once at four months or less. In certain embodiments, one or more doses of an anti-PD-1 antibody is administered in combination with one or more doses of a therapeutically effective amount of an anti-CD20/CD3 bispecific antibody, wherein one or more doses of the bispecific antibody is administered to a subject at a frequency of approximately once a day, once every two days, once every three days, once every four days, once every five days, once every six days, once a week, once every two weeks, once every three weeks, once every four weeks , once a month, once every two months, once every three months, once every four months, or less frequently. In certain embodiments, each dose of anti-CD20/CD3 antibody is administered as more than 1 part, eg, 2-5 parts (split dosing) over a specified dosing period. The anti-CD20/CD3 bispecific antibody can be administered in divided doses to reduce or eliminate cytokine spikes in response to antibody administration. Cytokine spikes are related to the clinical symptoms of cytokine release syndrome (cytokine storm) and infusion-related reactions seen in patients receiving anti-CD20 antibodies. In certain embodiments, the methods of the present invention provide for administering to a subject in need one or more doses of an anti-PD-1 antibody in combination with one or more doses of an anti-CD20/CD3 bispecific antibody, wherein the dose of the bispecific antibody is administered in sub-doses or more than 1 part, eg 2 parts, 3 parts, 4 parts or 5 parts, for a certain dosing period. In certain embodiments, the dose of the bispecific antibody is divided into 2 or more portions, where each portion contains an amount of antibody equal to the other portions. For example, a dose of anti-CD20/CD3 antibody containing 1000 micrograms may be administered once a week, with the dose administered in 2 portions within a week, each portion containing 500 micrograms. In certain embodiments, the dose of the bispecific antibody is administered in 2 or more portions, said portions containing unequal amounts of antibody, eg, more or less than in the first portion. For example, a dose of anti-CD20/CD3 antibody containing 1000 micrograms can be administered

- 5 042623 once a week, and the dose is administered in 2 parts within a week, while the first part contains 700 micrograms, and the second part contains 300 micrograms. As another example, a dose of anti-CD20/CD3 antibody containing 1000 micrograms can be administered once every 2 weeks, with the dose administered in 3 portions over a 2 week period, with the first portion containing 400 micrograms, the second portion containing 300 micrograms, and the third part contains 300 micrograms.

In certain embodiments, the present invention includes methods for inhibiting, slowing down, or stopping tumor metastasis or tumor infiltration into peripheral organs. The methods in accordance with this aspect include the introduction of a therapeutically effective amount of antibodies to PD-1 in need of this subject. In certain embodiments, the anti-PD-1 antibody is administered in combination with an anti-CD20/CD3 bispecific antibody.

According to specific embodiments, the present invention relates to methods for improving antitumor efficacy or increasing the degree of tumor inhibition. Methods in accordance with this aspect of the present invention comprise administering to a subject with a B cell cancer a therapeutically effective amount of an anti-PD-1 antibody prior to administering a therapeutically effective amount of an anti-CD20/CD3 bispecific antibody, wherein the anti-PD-1 antibody can be administered about 1 day, more than 1 day, more than 2 days, more than 3 days, more than 4 days, more than 5 days, more than 6 days, more than 7 days, or more than 8 days before the administration of the bispecific antibody. In certain embodiments, the methods provide for increasing the degree of tumor inhibition, for example, by about 20%, more than 20%, more than 30%, more than 40%, more than 50%, more than 60%, more than by 70% or more than 80%, compared with the subject who was administered bispecific antibody prior to the introduction of antibodies to PD-1.

In certain embodiments, the methods of the present invention comprise administering a therapeutically effective amount of an anti-PD-1 antibody to a subject with B cell cancer. In specific embodiments, the B cell cancer is Hodgkin's lymphoma or non-Hodgkin's lymphoma. In additional embodiments, the B cell cancer is indolent or aggressive. In certain embodiments, the subject did not respond to prior therapy or experienced a relapse after prior therapy. In certain embodiments, the methods of the present invention further comprise administering an anti-CD20/CD3 bispecific antibody to a subject with a CD20+ B cell cancer.

In certain embodiments, the methods of the present invention comprise administering a therapeutically effective amount of an anti-CD20/CD3 bispecific antibody to a subject with a CD20+ B cell cancer. In specific embodiments, the B cell cancer is acute lymphoblastic leukemia or chronic lymphocytic leukemia. In additional embodiments, the B cell cancer is indolent or aggressive. In certain embodiments, the subject did not respond to prior therapy or relapse after prior therapy (eg, with a CD20 inhibitor such as rituximab). In certain embodiments, the methods of the present invention further comprise administering an anti-PD-1 antibody to a subject with a B cell cancer.

In certain embodiments, the methods of the present invention provide for administering an anti-PD-1 antibody in combination with an anti-CD20/CD3 bispecific antibody to a subject in need as first-line (eg, initial treatment) treatment. In other embodiments, an anti-PD-1 antibody in combination with an anti-CD20/CD3 bispecific antibody is administered as a second-line treatment (eg, after prior therapy). For example, an anti-PD-1 antibody in combination with an anti-CD20/CD3 bispecific antibody is administered as a second line treatment to a subject who has relapsed following prior therapy with, for example, chemotherapy or rituximab.

In certain embodiments, the methods of the present invention are used to treat a patient with an MRD-positive disease. Minimal residual disease (MRD) refers to the small number of tumor cells that remain in a patient during or after treatment, and the patient may or may not show symptoms or signs of disease. Such residual tumor cells, if not eliminated, often cause a recurrence of the disease. The present invention includes methods for inhibiting and/or eliminating residual tumor cells in a patient after testing for MRD. MRD can be assessed according to methods known in the art (eg, flow cytometry to detect MRD). Methods in accordance with this aspect of the present invention provide for the administration of an antibody to PD-1 in combination with a bispecific antibody to CD20/CD3 in need of this subject.

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The methods of the present invention, in accordance with certain embodiments, provide for administering to a subject a therapeutically effective amount of each of an anti-PD-1 antibody and an anti-CD20/CD3 bispecific antibody in combination with a third therapeutic agent. The third therapeutic agent may be an agent selected from the group consisting of, for example, radiation, chemotherapy, surgery, cancer vaccine, PD-L1 inhibitor (e.g. anti-PD-L1 antibody), LAG3 inhibitor (e.g. anti-LAG3 antibody) , CTLA-4 inhibitor, TIM3 inhibitor, BTLA inhibitor, TIGIT inhibitor, CD47 inhibitor, indolamine 2,3-dioxygenase (IDO) inhibitor, vascular endothelial growth factor (VEGF) antagonist, Ang2 inhibitor, transforming growth factor beta (TGFe) inhibitor , an epidermal growth factor receptor (EGFR) inhibitor, an antibody to a tumor-specific antigen (eg, CA9, CA125, melanoma-associated antigen 3 (MAGE3), germline tumor antigen (CEA), vimentin, tumor M2-PK, prostate-specific antigen (PSA ), mucin-1, MART-1 and CA19-9), vaccines (e.g. Bacillus Calmette-Guerin), granulocyte-monocyte colony stimulating factor, cytotoxin, chemotherapeutic agent, IL-6R inhibitor, IL-4R inhibitor, IL-10 inhibitor , a cytokine such as IL-2, IL-7, IL-21, and IL-15, an anti-inflammatory drug such as corticosteroids, and non-steroidal anti-inflammatory drugs, and a dietary supplement such as antioxidants. In certain embodiments, antibodies can be administered in combination with therapy, including a chemotherapeutic agent, radiation, and surgery. In the context of this document, the phrase in combination with means that the antibodies are administered to the subject simultaneously with the introduction of the third therapeutic agent, immediately before it or immediately after it. In certain embodiments, the third therapeutic agent is administered as a combination formulation with antibodies. In a similar embodiment, the present invention includes methods comprising administering a therapeutically effective amount of an anti-PD-1 antibody in combination with an anti-CD20/CD3 bispecific antibody to a subject who is undergoing a background cancer therapy program. A background anticancer therapy program may include a course of administration, for example, of a chemotherapeutic agent or radiation. An anti-PD-1 antibody in combination with an anti-CD20/CD3 bispecific antibody can be added to a background anticancer therapy program. In some embodiments, the antibodies are added as part of a background therapy staging regimen where the subject's background anticancer therapy is gradually withdrawn over a period of time (e.g., in a staggered fashion), while the antibodies are administered to the subject at a constant dose, or with increasing dose , or with dose reduction, over a period of time.

In certain embodiments, the methods of the present invention comprise administering to a subject in need a therapeutically effective amount of an anti-PD-1 antibody in combination with a therapeutically effective amount of an anti-CD20/CD3 bispecific antibody, wherein administration of the antibodies results in an increased degree of tumor growth inhibition. In certain embodiments, tumor growth is inhibited by at least about 10%, about 20%, about 30%, about 40%, about 50%, about 60%, about 70%, or about 80% compared to a subject not subject to treatment, or a subject who was administered any of the antibodies as monotherapy. In certain embodiments, administration of an anti-PD-1 antibody and/or an anti-CD20/CD3 bispecific antibody results in increased tumor regression, shrinkage, and/or disappearance of the tumor. In certain embodiments, administration of an anti-PD-1 antibody and/or an anti-CD20/CD3 bispecific antibody results in a delay in tumor growth and development, e.g., tumor growth may be delayed by about 3 days, more than 3 days, about 7 days, more more than 7 days, more than 15 days, more than 1 month, more than 3 months, more than 6 months, more than 1 year, more than 2 years or more than 3 years compared to the subject , not to be treated, or a subject who was treated with any of the antibodies as monotherapy. In certain embodiments, administration of an anti-PD-1 antibody in combination with an anti-CD20/CD3 bispecific antibody provides for prevention of tumor recurrence and/or prolongation of survival of the subject, e.g., prolongation of survival of more than 15 days, more than 1 month, more than 3 months, more than 6 months, more than 12 months, more than 18 months, more than 24 months, more than 36 months, or more than 48 months compared to the subject not being treated, or a subject administered any of the antibodies as monotherapy. In certain embodiments, administration of the antibodies in combination provides an increase in progression-free survival or overall survival. In certain embodiments, administration of an anti-PD-1 antibody in combination with an anti-CD20/CD3 bispecific antibody provides an enhanced response and an increase in the duration of response in a subject, e.g., greater than 2%, greater than 3%, greater than 4%, greater than more than 5% more than 6% more than 7% more than 8% more than 9% more than 10% more than 20% more than 30% more than 40% or more than 50% over

- 7 042623 with a subject not to be treated, or a subject who receives any of the antibodies as monotherapy. In certain embodiments, administration of an anti-PD-1 antibody and/or an anti-CD20/CD3 bispecific antibody to a subject with B-cell cancer results in the complete disappearance of all evidence of the presence of tumor cells (complete response). In certain embodiments, administration of an anti-PD-1 antibody and/or an anti-CD20/CD3 bispecific antibody to a subject with B-cell cancer results in at least a 30% or greater reduction in tumor cell number or tumor size (partial response). In certain embodiments, administration of an anti-PD-1 antibody and/or an anti-CD20/CD3 bispecific antibody to a subject with B-cell cancer results in complete or partial disappearance of the tumor cells/lesions, including new measurable lesions. Tumor suppression can be measured using any of the methods known in the art, for example, x-ray studies, positron emission tomography (PET), computed tomography (CT), magnetic resonance imaging (MRI), cytology, histology, or molecular genetic analyses.

In certain embodiments, the combination of administered antibodies is safe and well tolerated by the patient, with no increase in undesirable side effect (e.g., increased cytokine release (cytokine storm) or increased T cell activation) compared to a patient administered with the bispecific antibody as monotherapy.

Antibodies to PD-1 and their antigen-binding fragments.

In accordance with certain exemplary embodiments of the present invention, the methods include administering a therapeutically effective amount of an anti-PD-1 antibody or antigen-binding fragment thereof. The term antibody in the context of this document includes immunoglobulin molecules containing four polypeptide chains, two heavy (H) chains and two light (L) chains connected to each other by disulfide bonds, as well as their multimers (eg, IgM). In a typical antibody, each heavy chain contains a heavy chain variable region (abbreviated herein as HCVR or VH) and a heavy chain constant region. The heavy chain constant region contains three domains, CH1, C _H 2 and C _H 3. Each light chain contains a light chain variable region (abbreviated herein as LCVR or VL) and a light chain constant region. The light chain constant region contains one domain (C _L 1). The VH and VL regions can further be divided into hypervariable regions called complementarity determining regions (CDRs) interspersed with regions that are more conserved called framework regions (FRs). Each V _H and V _L consists of three CDRs and four FRs arranged, from amino to carboxy, in the following order: FR1, CDR1, FR2, CDR2, FR3, CDR3, FR4. According to excellent embodiments of the present invention, the FR of an anti-IL-4R antibody (or an antigen-binding portion thereof) may be identical to human germline sequences, or may be naturally or artificially modified. Amino acid consensus sequence can be determined based on a comparative analysis of two or more CDRs.

The term antibody as used herein also includes antigen-binding fragments of complete antibody molecules. The terms antigen-binding portion of an antibody, antigen-binding fragment of an antibody, etc. in the context of this document include any naturally occurring, enzymatically produced, synthetic or genetically engineered polypeptide or glycoprotein that specifically binds an antigen to form a complex. Antigen-binding antibody fragments can be generated, for example, from whole antibody molecules using any suitable standard techniques, such as proteolytic cleavage techniques or recombinant DNA genetic engineering techniques involving the manipulation and expression of DNA encoding the variable and optionally constant domains of antibodies. Such DNA is known and/or readily available, for example from commercial sources, DNA libraries (including, for example, antibody phage libraries), or it can be synthesized. The DNA can be sequenced and chemically manipulated using molecular biology techniques, for example, to place one or more variable and/or constant domains in an appropriate configuration, or to include codons, introduce cysteine residues, modify, add or remove amino acids, etc.

Non-limiting examples of antigen-binding fragments include: (i) Fab fragments; (ii) F(ab')2 fragments; (iii) Fd fragments; (iv) Fv fragments; (v) single chain Fv molecules (scFv); (vi) dAb fragments; and (vii) minimal recognition units consisting of amino acid residues that mimic an antibody hypervariable region (eg, a distinguished complementarity determining region (CDR), such as a CDR3 peptide), or a sterically restricted FR3-peptide. CDR3-FR4. Other engineered molecules such as domain-specific antibodies, single-domain antibodies, domain-deleted antibodies, chimeric antibodies, CDR-grafted antibodies, diabodies, tribodies, tetrabodies, minibodies, nanoantibodies (e.g. monovalent nanoantibodies, bivalent nanoantibodies, etc.) .e.), small modular protein (SMIP) immunopharmaceuticals, and shark IgNAR variable domains are also encompassed by the expression antigen-binding fragment in the context of this document.

An antigen binding fragment of an antibody will typically contain at least one variable domain. The variable domain may be of any size or amino acid composition, and will typically contain at least one CDR that is adjacent to or in frame with one or more framework sequences. In antigen-binding fragments with a VH domain associated with a V _L domain, the VH and VL domains may be positioned relative to each other in any suitable configuration. For example, the variable region may be dimeric and contain VH-VH, VH-V _L or V _L -V _L dimers. Alternatively, the antigen binding fragment of an antibody may contain a monomeric VH or VL domain.

In certain embodiments, an antigen-binding fragment of an antibody may comprise at least one variable domain covalently linked to at least one constant domain. Non-limiting exemplary variable and constant domain configurations that can be found within an antigen-binding fragment of an antibody of the present invention include: (i) VH-CH1; (ii) VH-CH2; (iii) VH-CH3; (iv) VH-CH1-CH2; (v) VH-CH1-CH2-CH3; (vi) Vh-Ch2-Ch3; (vii) Vh-Cl; (viii) Vl-Ch1; (ix) Vl-Ch2; (x) Vl-Ch3; (xi) Vl-Ch1-Ch2; (xii) Vl-Ch1-Ch2-Ch3; (xiii) V _l -C _h 2-C _h 3 and (xiv) V _l -C _l . In any configuration of the variable and constant domains, including any of the above illustrative configurations, the variable and constant domains can either be directly connected to each other, or can be connected through a full or partial hinge region or a linker region. The hinge region may consist of at least 2 (e.g., 5, 10, 15, 20, 40, 60 or more) amino acids that provide a flexible or semi-flexible connection of adjacent variable and/or constant domains within a single polypeptide molecule. Moreover, an antigen-binding fragment of an antibody of the present invention may comprise a homodimer or heterodimer (or other multimer) of any of the above variable and constant domain configurations non-covalently linked to each other and/or to one or more monomeric VH or V _L domains ( for example, via disulfide(s) bond(s)).

The term antibody as used herein also includes polyspecific (eg, bispecific) antibodies. A polyspecific antibody or antigen-binding fragment of an antibody will typically contain at least two different variable domains, where each variable domain is capable of specifically binding to a different antigen or different epitope on the same antigen. Any multispecific antibody format can be adapted for use in the context of an antibody or antigen-binding fragment of an antibody of the present invention using conventional techniques known in the art. For example, the present invention includes methods using bispecific antibodies wherein one arm of the immunoglobulin is specific for PD-1 or a fragment thereof and the other arm of the immunoglobulin is specific for a second therapeutic target or conjugated to a therapeutic compound. Exemplary bispecific formats that can be used in the context of the present invention include, without limitation, for example, scFv-based or diabody bispecific formats, IgGscFv fusion bispecific formats, Ig dual variable domain (DVD), Quadroma, overhang antibodies into the pit, common light chain antibodies (e.g., common light chain antibodies with a ridge into the pit structure, etc.), CrossMab, CrossFab, a SEED-derived antibody ((SEED)body), an antibody produced by mediated leucine zipper dimerization, Duobody, IgG1/IgG2, IgG with dual acting Fab (DAF) and Mab ² bispecific formats (see e.g. Klein et al. 2012, mAbs 4:6, 1-11 and references cited therein, for review of the formats listed above). Bispecific antibodies can also be constructed using peptide/nucleic acid conjugation, for example, where non-naturally occurring amino acids with cross-reactivity are used to generate site-specific antibody oligonucleotide conjugates, which then self-assemble into multimeric complexes with specific composition, valence, and geometry. (See, for example, Kazane et al., J. Am. Chem. Soc. [Epub: Dec. 4, 2012]).

The antibodies used in the methods of the present invention may be human antibodies. As used herein, the term human antibody is intended to include antibodies with variable and constant regions derived from human germline immunoglobulin sequences. The human antibodies of the present invention may, however, contain amino acid residues not encoded by human germline immunoglobulin sequences (e.g., due to mutations introduced by in vitro random or site-specific mutagenesis or due to in vivo somatic mutation), for example, in CDRs and in particular , CDR3. However, in the context of this document, the term human antibody is not intended to include antibodies in which CDR sequences derived from the germline of another mammalian species, such as a mouse, have been grafted onto human framework sequences.

- 9 042623

The antibodies used in the methods of the present invention may be recombinant human antibodies. The term recombinant human antibody as used herein is intended to include all human antibodies produced, expressed, generated or isolated by recombinant methods, such as antibodies expressed using a recombinant expression vector transfected into a host cell (described further below). ), antibodies isolated from a recombinant combinatorial human antibody library (described further below), antibodies derived from an animal (e.g., mouse) that is transgenic for human immunoglobulin genes (see, e.g., Taylor et al. (1992) Nucl. Acids Res. 20:6287-6295), or antibodies produced, expressed, constructed, or isolated by other means, which involve combining human immunoglobulin gene sequences with other DNA sequences. Such recombinant human antibodies contain variable and constant regions derived from human germline immunoglobulin sequences. However, in certain embodiments, such human recombinant antibodies are subjected to in vitro mutagenesis (or, in the case of an animal transgenic for human Ig sequences, in vivo somatic mutagenesis), and hence the amino acid sequences of the VH and VL regions of the recombinant antibodies are sequences that, although derived from or related to human germline VH and V _L sequences, may not naturally exist within the in vivo human germline antibody array.

In certain embodiments, the antibodies used in the methods of the present invention specifically bind PD-1. The term specifically binds, etc. means that the antibody, or antigen-binding fragment thereof, forms a complex with the antigen that is relatively stable under physiological conditions. Methods for determining whether an antibody specifically binds to an antigen are well known in the art and include, for example, equilibrium dialysis, surface plasmon resonance, and the like. For example, an antibody that specifically binds PD-1 in the context of the present invention includes antibodies that bind PD-1, or a portion thereof, with a KD of less than about 500 nM, less than about 300 nM, less than about 200 nM, less than about 100 nM , less than about 90 nM, less than about 80 nM, less than about 70 nM, less than about 60 nM, less than about 50 nM, less than about 40 nM, less than about 30 nM, less than about 20 nM, less than less than about 10 nM, less than about 5 nM, less than about 4 nM, less than about 3 nM, less than about 2 nM, less than about 1 nM, or less than about 0.5 nM, as measured in a phenomenon-based assay surface plasmon resonance. An isolated antibody that specifically binds human PD-1 may, however, be cross-reactive with other antigens, such as PD-1 molecules from other (non-human) species.

In accordance with certain exemplary embodiments of the present invention, an anti-PD-1 antibody, or antigen-binding fragment thereof, comprises a heavy chain variable region (HCVR), a light chain variable region (LCVR), and/or complementarity determining regions (CDRs) comprising any of the antibody amino acid sequences. to PD-1 as set forth in U.S. Patent Application Publication No. 20150203579. In certain illustrative embodiments, an anti-PD-1 antibody, or antigen-binding fragment thereof, that can be used in the context of the methods of the present invention, comprises variable heavy chain complementarity determining regions (HCDRs). heavy chain variable region (HCVR) containing the amino acid sequence of SEQ ID NO: 1 and complementarity determining regions (LCDR) of the light chain variable region (LCVR) containing the amino acid sequence of SEQ ID NO: 2. In certain embodiments, an antibody to PD-1 or its antigen-binding fragment contains three HCDRs (HCDR1, HCDR2 and HCDR3) and three LCDRs (LCDR1, LCDR2 and LCDR3), where HCDR1 contains the amino acid sequence of SEQ ID NO: 3; HCDR2 contains the amino acid sequence of SEQ ID NO: 4; HCDR3 contains the amino acid sequence of SEQ ID NO: 5; LCDR1 contains the amino acid sequence of SEQ ID NO: 6; LCDR2 contains the amino acid sequence of SEQ ID NO: 7; and LCDR3 comprises the amino acid sequence of SEQ ID NO: 8. In still other embodiments, the anti-PD-1 antibody or antigen binding fragment thereof comprises an HCVR comprising SEQ ID NO: 1 and an LCVR comprising SEQ ID NO: 2. In certain embodiments, the methods the present invention provides for the use of an anti-PD-1 antibody wherein the antibody comprises a heavy chain comprising the amino acid sequence of SEQ ID NO: 9. In some embodiments, an anti-PD-1 antibody comprises a light chain comprising the amino acid sequence of SEQ ID NO: 10. An exemplary antibody containing a heavy chain containing the amino acid sequence of SEQ ID NO: 9 and a light chain containing the amino acid sequence of SEQ ID NO: 10 is a fully human anti-PD-1 antibody known as REGN2810. In accordance with certain exemplary embodiments, the methods of the present invention include

- 10 042623 use of REGN2810 or its bioequivalent. The term bioequivalent in the context of this document refers to antibodies to PD-1 or PD-1 binding proteins or fragments thereof, which are pharmaceutical equivalents or pharmaceutical variants, the rate and/or degree of absorption of which is not significantly different from those of REGN2810 when administered in the same molar dose under similar experimental conditions, both as a single dose and as a multiple dose. In the context of the present invention, the term refers to antigen-binding proteins that bind to PD-1, which are not characterized by clinically significant differences with REGN2810 in terms of their safety, purity and/or activity.

Other anti-PD-1 antibodies that can be used in the context of the methods of the present invention include, for example, the antibodies referred to and known in the art as nivolumab (US 8008449), pembrolizumab (US 8354509), MEDI0608 (US 8609089), pidilizumab ( US 8686119), or any other of the PD-1 antibodies set forth in US Pat.

Anti-PD-1 antibodies used in the context of the methods of the present invention may have pH-dependent binding characteristics. For example, an anti-PD-1 antibody for use in the methods of the present invention may have reduced ability to bind to PD-1 at acidic pH as compared to neutral pH. Alternatively, an anti-PD-1 antibody of the present invention may have an increased ability to bind to its antigen at acidic pH as compared to neutral pH. The expression acidic pH includes pH values less than about 6.2, for example, about 6.0, 5.95, 5.9, 5.85, 5.8, 5.75, 5.7, 5.65, 5.6, 5.55, 5.5, 5.45, 5.4, 5.35, 5.3, 5.25, 5.2, 5.15, 5.1, 5.05, 5, 0 or less. In the context of this document, the expression neutral pH means a pH of from about 7.0 to about 7.4. The expression neutral pH includes pH values of approximately 7.0, 7.05, 7.1, 7.15, 7.2, 7.25, 7.3, 7.35 and 7.4.

In certain cases, the reduced ability to bind to PD-1 at acidic pH compared to neutral pH is expressed as the ratio of the KD value of an antibody that binds to PD-1 at acidic pH to the KD value of an antibody that binds to PD-1 at neutral pH (or vice versa). For example, for the purposes of the present invention, an antibody or antigen-binding fragment thereof may be considered to have a reduced ability to bind to PD-1 at acidic pH compared to neutral pH if the antibody or antigen-negative fragment thereof has an acidic pH/neutral pH KD ratio of about 3.0 or more. In certain exemplary embodiments, the acidic pH/neutral pH KD ratio for an antibody or antigen-binding fragment of the present invention may be about 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6, 0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, 9.5, 10.0, 10.5, 11.0, 11.5, 12.0, 12.5, 13.0, 13.5, 14.0, 14.5, 15.0, 20.0, 25.0, 30.0, 40.0, 50.0, 60.0, 70, 0, 100.0 or more.

Antibodies with pH-dependent binding characteristics can be generated, for example, by screening an antibody population for reduced (or increased) ability to bind to a particular antigen at acidic pH versus neutral pH. In addition, the formation of antibodies with pH-dependent characteristics can provide modifications to the antigen-binding domain at the amino acid level. For example, by replacing one or more amino acids of the antigen-binding domain (eg, within the CDR) with a histidine residue, an antibody with reduced antigen-binding ability at acidic pH as compared to neutral pH can be obtained. In the context of this document, the expression acidic pH means a pH of 6.0 or less.

Bispecific antibodies to CD20/CD3.

In accordance with certain exemplary embodiments of the present invention, the methods involve administering a therapeutically effective amount of a bispecific antibody that specifically binds CD3 and CD20. Such antibodies may be referred to herein, for example, as CD20/CD3 or CD20xCD3 or CD20xCD3 bispecific antibodies or similar terminology.

As used herein, the expression bispecific antibody refers to an immunoglobulin protein comprising at least a first antigen-binding domain and a second antigen-binding domain. In the context of the present invention, a first antigen-binding domain specifically binds a first antigen (eg, CD20) and a second antigen-binding domain specifically binds a second, distinct antigen (eg, CD3). Each antigen-binding domain of a bispecific antibody contains a heavy chain variable domain (HCVR) and a light chain variable domain (LCVR), each containing three CDRs. In the context of a bispecific antibody, the CDRs of the first antigen-binding domain may be denoted by the prefix A, and the CDRs of the second antigen-binding domain may be denoted by the prefix B. Thus, the CDRs of the first antigen-binding domain may be referred to herein as A-HCDR1, A-HCDR2, and A-HCDR3; and the CDRs of the second antigen-binding domain may herein be referred to as B-HCDR1, BHCDR2, and B-HCDR3.

- 11 042623

Each of the first antigen-binding domain and the second antigen-binding domain is attached to a separate domain capable of forming multimers. As used herein, a multimeric domain is a macromolecule, protein, polypeptide, peptide, or amino acid that is capable of association with a second multimeric domain of the same or similar structure or composition. In the context of the present invention, a component capable of forming multimers is the Fc portion of an immunoglobulin (containing a C _H 2 -CH ₃ domain), for example, the Fc domain of an IgG selected from the IgG1, IgG2, IgG3 and IgG4 isotypes, as well as any allotype within each isotypic group.

The bispecific antibodies of the present invention typically contain two domains capable of forming multimers, for example two Fc domains, each of which is an independent part of a separate antibody heavy chain. The first and second multimeric domains may be of the same IgG isotype, such as IgG1/IgG1, IgG2/IgG2, IgG4/IgG4. Alternatively, the first and second multimeric domains may be of different IgG isotypes, such as IgG1/IgG2, IgG1/IgG4, IgG2/IgG4, etc.

Any bispecific antibody format or technology can be used to produce the bispecific antigen-binding molecules of the present invention. For example, an antibody or fragment thereof with a first specificity for antigen binding may be operably linked (e.g., by chemical bonding, gene fusion, non-covalent linkage, or otherwise) to one or more other compounds, such as another antibody or antibody fragment with a second specificity. in relation to antigen binding, to form a bispecific antigen-binding molecule. Specific illustrative bispecific formats that can be used in the context of the present invention include, without limitation, for example, scFv-based or diabody bispecific formats, IgG-scFv fusion bispecific formats, Ig double variable domains (DVD), Quadroma, antibodies tab-in-pit, common light chain antibodies (e.g., tab-in-pit common light chain antibodies, etc.), CrossMab, CrossFab, SEED-derived antibody ((SEED)body), antibody, produced by leucine zipper mediated dimerization, Duobody, IgGl/IgG2, IgG with dual acting Fab (DAF) and Mab ² bispecific formats (see e.g. Klein et al. 2012, mAbs 4:6, 1-11 and cited therein links, for an overview of the formats listed above).

In the context of the bispecific antibodies of the present invention, Fc domains may include one or more amino acid changes (eg, insertions, deletions or substitutions) compared to the naturally occurring version of the Fc domain. For example, the present invention relates to bispecific antigen-binding molecules containing one or more modifications in the Fc domain, which provide the formation of a modified Fc domain, characterized by a modified binding interaction (eg, increased or decreased) between Fc and FcRn. In one embodiment, the bispecific antigen binding molecule comprises a modification in the CH2 or C _H 3 region, where the modification provides an increase in the affinity of the Fc domain for FcRn in an acidic environment (e.g., in the endosome, where the pH is in the range of about 5.5 to about 6.0). Non-limiting examples of such Fc modifications are disclosed in US Patent Application Publication No. 20150266966, incorporated herein in its entirety.

The present invention also relates to bispecific antibodies comprising a first C _H 3 domain and a second Ig C _H 3 domain, wherein the first and second Ig C _H 3 domains differ from each other by at least one amino acid, and wherein at least one amino acid difference results in a reduction in the ability of the bispecific antibody to bind to protein A compared to a bispecific antibody lacking that amino acid difference. In one embodiment, the first Ig CH ₃ domain binds protein A, and the second Ig _CH 3 domain contains a mutation that reduces or eliminates the ability to bind to protein A, such as an H95R modification (according to the IMGT mutation numbering in exons; H435R according to EU numbering). The second CH3 may additionally provide for the Y96F modification (as per IMGT; Y436F as per EU). Additional modifications that can be found within the second _CH 3 include: D16E, L18M, N44S, K52N, V57M and V82I (according to IMGT; D356E, L358M, N384S, K392N, V397M and V422I according to EU) in the case of IgG1 antibodies; N44S, K52N and V82I (IMGT; N384S, K392N and V422I according to EU) in the case of IgG2 antibodies; and Q15R, N44S, K52N, V57M, R69K, E79Q and V82I (as per IMGT; Q355R, N384S, K392N, V397M, R409K, E419Q and V422I as per EU) for IgG4 antibodies.

In certain embodiments, the Fc domain may be chimeric, combining Fc sequences derived from immunoglobulins of more than one isotype. For example, a chimeric Fc domain may comprise part or all of a CH2 sequence derived from the C _H 2 region of human IgG1, human IgG2, or human IgG4, and part or all of a CH3 sequence derived from human IgG1, human IgG2, or human IgG4. The chimeric Fc domain may also contain a chimeric hinge region. For example, a chimeric hinge may contain a sequence

- 12 042623 an upper hinge sequence derived from the hinge region of human IgG1, human IgG2 or human IgG4, in combination with a lower hinge sequence derived from the hinge region of human IgG1, human IgG2 or human IgG4. A specific example of a chimeric Fc domain that can be included in any of the antigen binding molecules set forth herein is, from N- to C-terminus: [C _H 1 IgG4] - [upper IgG4 hinge] - [lower IgG2 hinge] - [CH2 IgG4] - [CH3 IgG4]. Another example of a chimeric Fc domain that can be included in any of the antigen binding molecules set forth herein is, from N- to C-terminus: [ _CH 1 IgG1] - [upper hinge IgG1] - [lower hinge IgG2] - [CH2 IgG4] - [CH3 IgG1]. These and other examples of chimeric Fc domains that can be included in any of the antigen binding molecules of the present invention are described in US Patent Application Publication No. 20140243504, which is incorporated herein in its entirety. Chimeric Fc domains with this common structural organization, and variants thereof, may have an altered ability to bind the Fc receptor, which in turn affects the effector function of Fc.

In accordance with certain exemplary embodiments of the present invention, the anti-CD20/CD3 bispecific antibody or antigen-binding fragment thereof comprises heavy chain variable regions (A-HCVR and B-HCVR), light chain variable region (LCVR), and/or complementarity determining regions (CDRs) containing any of the amino acid sequences of the CD20/CD3 bispecific antibodies set forth in U.S. Patent Application Publication No. 20150266966. : (a) a first antigen-binding arm comprising the heavy chain variable region (A-HCVR) complementarity-determining regions (A-HCDR1, A-HCDR2 and A-HCDR3) containing the amino acid sequence of SEQ ID NO: 11 and complementarity-determining regions (LCDR) light chain variable region of the light chain (LCVR), containing the amino acid sequence of SEQ ID NO: 12; and (b) a second antigen-binding arm comprising the heavy chain CDR (B-HCDR1, B-HCDR2 and B-HCDR3) of HCVR (BHCVR) containing the amino acid sequence of SEQ ID NO: 13 and the light chain CDR of LCVR containing the amino acid sequence of SEQ ID NO: 12. According to certain embodiments, A-HCDR1 comprises the amino acid sequence of SEQ ID NO: 14; AHCDR2 contains the amino acid sequence of SEQ ID NO: 15; A-HCDR3 contains the amino acid sequence of SEQ ID NO: 16; LCDR1 contains the amino acid sequence of SEQ ID NO: 17; LCDR2 contains the amino acid sequence of SEQ ID NO: 18; LCDR3 contains the amino acid sequence of SEQ ID NO: 19; B-HCDR1 contains the amino acid sequence of SEQ ID NO: 20; B-HCDR2 contains the amino acid sequence of SEQ ID NO: 21; and B-HCDR3 comprises the amino acid sequence of SEQ ID NO: 22. In still other embodiments, the CD20/CD3 bispecific antibody or antigen-binding fragment thereof comprises: (a) an HCVR-containing first antigen-binding arm (A-HCVR) comprising SEQ ID NO: 11, and LCVR containing SEQ ID NO: 12; and (b) a second antigen binding arm comprising HCVR (B-HCVR) comprising SEQ ID NO: 13 and LCVR comprising SEQ ID NO: 12.

Other anti-CD20/CD3 bispecific antibodies that may be used in the context of the methods of the present invention include, for example, any of the antibodies set forth in US Patent Publication Nos. 20140088295 and 20150166661.

Combined types of therapy.

The methods of the present invention, in accordance with certain embodiments, provide for administering to a subject an anti-CD20/CD3 bispecific antibody in combination with an anti-PD-1 antibody. In certain embodiments, the methods of the present invention provide for the administration of antibodies to provide additive or synergistic activity for the treatment of a cancer, preferably a hematopoietic tissue cancer, more preferably a B-cell cancer (e.g., non-Hodgkin's lymphoma or acute lymphoblast leukemia). In the context of this document, the expression in combination with means that the anti-CD20/CD3 bispecific antibody is administered before, simultaneously with, or after administration of the anti-PD-1 antibody. The expression in combination with also includes sequential or parallel administration of an anti-PD-1 antibody and an anti-CD20/CD3 bispecific antibody. For example, in the case of administration prior to the anti-CD20/CD3 bispecific antibody, the anti-PD-1 antibody may be administered more than 150 hours, approximately 150 hours, approximately 100 hours, approximately 72 hours, approximately 60 hours, approximately 48 hours, approximately 36 hours, approximately 24 hours, approximately 12 hours, approximately 10 hours, approximately 8 hours, approximately 6 hours, approximately 4 hours, approximately 2 hours, approximately 1 hour, approximately 30 minutes, approximately 15 minutes, or approximately 10 minutes before anti-CD20/CD3 bispecific antibody administration . When administered after the anti-CD20/CD3 bispecific antibody, the anti-PD-1 antibody may be administered after about 10 minutes, about 15 minutes, about 30 minutes, about 1 hour, about 2 hours,

- 13 042623 about 4 hours, about 6 hours, about 8 hours, about 10 hours, about 12 hours, about 24 hours, about 36 hours, about 48 hours, about 60 hours, about 72 hours, or more than 72 hours after administration of the bispecific antibodies to CD20/CD3. Administration simultaneously with an anti-CD20/CD3 bispecific antibody means that the anti-PD-1 antibody is administered to the subject in a separate dosage form within less than 5 minutes (before, after, or simultaneously) of administration of the anti-CD20/CD3 bispecific antibody, or is administered to the subject as a single combined a dosage formulation containing both an anti-PD-1 antibody and an anti-CD20/CD3 bispecific antibody.

In certain embodiments, the methods of the present invention provide for the administration of a third therapeutic agent, wherein the third therapeutic agent is an antineoplastic drug. As used herein, an anticancer drug means any agent useful in the treatment of cancer, including, without limitation, cytotoxins and agents such as antimetabolites, alkylating agents, anthracyclines, antibiotics, antimitotics, procarbazine, hydroxyurea, asparaginase, corticosteroids, mitotane (O, P'-(DDD)), biological agents (eg antibodies and interferons), and radioactive substances. In the context of this document, a cytotoxin or cytotoxic agent also refers to a chemotherapeutic agent, and means any agent that is detrimental to cells. Examples include Taxol® (paclitaxel), temozolomide, cytochalasin B, gramicidin D, ethidium bromide, emetine, cisplatin, mitomycin, etoposide, tenoposide, vincristine, vinblastine, colchicine, doxorubicin, daunorubicin, dihydroxyanthracindione, mitoxantrone, mithramycin, actinomycin D, 1- dihydrotestosterone, glucocorticoids, procaine, tetracaine, lidocaine, propranolol and puromycin and analogues or homologues thereof.

In certain embodiments, the methods of the present invention comprise administering a third therapeutic agent selected from the group consisting of radiation, surgery, cancer vaccine, PD-L1 inhibitor (e.g., anti-PD-L1 antibody), LAG-3 inhibitor, CTLA- 4 (eg, ipilimumab), TIM3 inhibitor, BTLA inhibitor, TIGIT inhibitor, CD47 inhibitor, other T cell co-inhibitor or ligand antagonist (eg, antibodies to CD-28, 2B4, LY108, LAIR1, ICOS, CD160, or VISTA), inhibitor indolamine-2,3-dioxygenase (IDO), a vascular endothelial growth factor (VEGF) antagonist (e.g., a VEGF trap such as aflibercept or other VEGF-inhibiting fusion protein as set forth in US 7,087,411, or an anti-VEGF antibody or antigen-binding protein thereof fragment (eg, bevacizumab or ranibizumab) or small molecule VEGF receptor kinase inhibitor (eg, sunitinib, sorafenib, or pazopanib)), Ang2 inhibitor (eg, nesvacumab), transforming growth factor beta (TGFe) inhibitor, epidermal growth factor receptor (EGFR) inhibitor ) (eg, erlotinib, cetuximab), co-stimulatory receptor agonist (eg, glucocorticoid-induced TNFR-related protein agonist), antibodies to a tumor-specific antigen (eg, CA9, CA125, melanoma-associated antigen 3 (MAGE3), embryonic tumor antigen (CEA ), vimentin, tumor M2-PK, prostate-specific antigen (PSA), mucin-1, MART-1, and CA19-9), vaccines (e.g., Bacillus Calmette-Guerin, antitumor vaccine), adjuvant to enhance antigen presentation (e.g. , granulocyte-monocyte colony-stimulating factor), cytotoxin, chemotherapeutic agent (eg, dacarbazine, temozolomide, cyclophosphamide, docetaxel, doxorubicin, daunorubicin, cisplatin, carboplatin, gemcitabine, methotrexate, mitoxantrone, oxaliplatin, paclitaxel, and vincristine), radiotherapy, IL-6 inhibitor, sarilumab), IL-4R inhibitor (eg dupilumab), IL-10 inhibitor, cytokine such as IL-2, IL-7, IL-21 and IL-15, antibody drug conjugate (ADC) (eg , ADC antibody to CD19-DM4 and ADC antibody to DS6-DM4), T cells with chimeric antigen receptors (eg, targeting CD19 T cells), anti-inflammatory drug (eg, corticosteroids and non-steroidal anti-inflammatory drugs), and dietary supplement such as antioxidants.

In certain embodiments, the methods of the present invention provide for the use of an anti-PD-1 antibody and an anti-CD20/CD3 bispecific antibody in combination with radiation therapy to provide long-term antitumor responses and/or improve survival in cancer patients. In some embodiments, the methods of the present invention involve administering radiation therapy before, concurrently, or after administration of an anti-PD-1 antibody and an anti-CD20/CD3 bispecific antibody in a patient with cancer. For example, radiation therapy can be applied in one or more doses to tumor foci after administration of one or more doses of antibodies. In some embodiments, radiation therapy can be applied locally to a tumor site to increase the local immunogenicity of a patient's tumor (adjuvant radiation) and/or to kill tumor cells (ablative radiation therapy) following systemic administration of an anti-PD-1 antibody and/or bispecific antibodies to CD20/CD3. According to certain options

The antibodies can be used in combination with radiation therapy and a chemotherapeutic agent (eg temozolomide or cyclophosphamide) or a VEGF antagonist (eg aflibercept).

Pharmaceutical compositions and administration.

The present invention includes methods that involve administering to a subject an anti-PD-1 antibody in combination with an anti-CD20/CD3 bispecific antibody, wherein the antibodies are contained in a single or combined (single) pharmaceutical composition. Pharmaceutical compositions of the present invention may be formulated with suitable carriers, excipients, and other means that provide suitable transfer, delivery, tolerability, and so on. Many suitable formulations can be found in the reference book known to all pharmaceutical chemists: Remington's Pharmaceutical Sciences, Mack Publishing Company, Easton, PA. Such formulations include, for example, powders, pastes, ointments, jellies, waxes, oils, lipid containing lipid (cationic or anionic) vesicles (e.g. LIPOFECTIN™), DNA conjugates, anhydrous absorbent pastes, oil-in-water emulsions and water. in oil, Carbowax in the form of emulsions (polyethylene glycols of various molecular weights), semi-solid gels and semi-solid mixtures containing Carbowax. See also Powell et al. Compendium of excipients for parenteral formulations PDA (1998) J Pharm Sci Technol 52:238-311.

Various delivery systems are known and can be used to administer the pharmaceutical composition of the present invention, for example, incorporation into liposomes, microparticles, microcapsules, recombinant cells capable of expressing mutant viruses, receptor-mediated endocytosis (see, for example, Wu et al., 1987 , J Biol Chem 262:4429-4432). Routes of administration include, without limitation, intradermal, intramuscular, intraperitoneal, intravenous, subcutaneous, intranasal, epidural, and oral routes of administration. The composition may be administered by any suitable route, for example, by infusion or bolus injection, by absorption through epithelial or mucocutaneous linings (eg, oral mucosa, rectal and small intestinal mucosa, etc.), and may be administered together with other biologically active agents.

The pharmaceutical composition of the present invention can be delivered subcutaneously or intravenously using a standard needle and syringe. In addition, with respect to subcutaneous delivery, a pen-type delivery device can be easily used to deliver the pharmaceutical composition of the present invention. Such a pen delivery device may be reusable or disposable. A refillable pen delivery device typically uses a replaceable cartridge that contains a pharmaceutical composition. Once all of the pharmaceutical composition from the cartridge has been administered and the cartridge is empty, the empty cartridge can be easily discarded and replaced with a new cartridge that contains the pharmaceutical composition. The pen delivery device can then be reused. The disposable pen delivery device does not have a replaceable cartridge. Instead, a disposable pen-type delivery device comes pre-filled with a pharmaceutical composition contained in a reservoir within the device. Once the reservoir is depleted of the pharmaceutical composition, the device is completely discarded.

In certain cases, the pharmaceutical composition may be delivered using a controlled release system. In one embodiment, a pump may be used. According to another embodiment, polymeric substances can be used; see Medical Applications of Controlled Release, Langer and Wise (eds.), 1974, CRC Pres., Boca Raton, Florida. In yet another embodiment, the controlled release system can be placed near the target of the composition so that only a fraction of the systemic dose is required (see, for example, Goodson, 1984, in Medical Applications of Controlled Release, supra, vol. 2, 115-138 s). Other controlled release systems are discussed in Langer, 1990, Science 249:1527-1533.

Injectable preparations may include dosage forms for intravenous, subcutaneous, intradermal and intramuscular injections, drip infusions, etc. Such injectable preparations can be obtained using methods. For example, injectable preparations can be obtained, for example, by dissolving, suspending or emulsifying the antibody described above or a salt thereof in a sterile aqueous or oily medium commonly used for injection. As an aqueous injection medium, there are, for example, physiological saline, isotonic solution containing glucose and other excipients, etc., which can be used in combination with an appropriate solubilizing agent such as alcohol (for example, ethanol), polyhydric alcohol (e.g. propylene glycol, polyethylene glycol), nonionic surfactant (e.g. polysorbate 80, HCO-50 (polyoxyethylene (50 mol) adduct of hydrogenated castor oil)], etc. As the oil medium, e.g. sesame oil, soybean oil etc., which can be used in combination with a solubilizing agent such as benzyl benzoate, benzyl alcohol, etc. The injection solution thus obtained

- 15 042623 preferably fill the appropriate ampoule.

Advantageously, the above-described pharmaceutical compositions for oral or parenteral use are formulated into unit dosage forms suitable for adjusting the dosage of the active ingredients. Such unit dosage forms include, for example, tablets, pills, capsules, injectable solutions (ampoules), suppositories, and the like.

Introduction schemes.

The present invention includes methods comprising administering an anti-PD-1 antibody to a subject at a dosing frequency of approximately four times a week, twice a week, once a week, once every two weeks, once every three weeks, once every four weeks, once every five weeks, once every six weeks, once every eight weeks, once every twelve weeks or less, provided that a therapeutic response is achieved. In certain embodiments, the present invention includes methods comprising administering an anti-CD20/CD3 bispecific antibody to a subject at a dosing frequency of approximately four times a week, twice a week, once a week, once every two weeks, once every three weeks, one once every four weeks, once every five weeks, once every six weeks, once every eight weeks, once every twelve weeks or less, provided that a therapeutic response is achieved. In certain embodiments, the methods involve administering an anti-PD-1 antibody in combination with an anti-CD20/CD3 bispecific antibody at a dosing frequency of approximately four times a week, twice a week, once a week, once every two weeks, once every three weeks, once every four weeks, once every five weeks, once every six weeks, once every eight weeks, once every nine weeks, once every twelve weeks or less, provided that a therapeutic response is achieved.

In accordance with certain embodiments of the present invention, multiple doses of an anti-PD-1 antibody in combination with an anti-CD20/CD3 bispecific antibody can be administered to a subject over a period of time. Methods in accordance with this aspect of the present invention provide for the sequential administration of one or more doses of an anti-PD-1 antibody to a subject in combination with one or more doses of an anti-CD20/CD3 bispecific antibody. As used herein, sequential administration means that each dose of an antibody is administered to a subject at different points in time, eg, on different days separated by a predetermined interval (eg, hours, days, weeks, or months). The present invention includes methods that sequentially administer to a patient a single initial dose of an anti-PD1 antibody, followed by one or more second-line doses of an anti-PD-1 antibody, and optionally followed by one or more doses of a third-line anti-PD-1 antibody. In certain embodiments, the methods further comprise sequentially administering to the patient a single initial dose of the anti-CD20/CD3 bispecific antibody, followed by one or more doses of the second line of the bispecific antibody, and optionally followed by one or more doses of the third line of the bispecific antibody.

In accordance with certain embodiments of the present invention, multiple doses of an anti-PD-1 antibody and an anti-CD20/CD3 bispecific antibody can be administered to a subject over a period of time. The methods in accordance with this aspect of the present invention provide for sequential administration of multiple doses of an anti-PD-1 antibody and an anti-CD20/CD3 bispecific antibody to a subject. As used herein, sequential administration means that each dose of an anti-PD-1 antibody in combination with a bispecific antibody is administered to a subject at different time points, e.g., on different days separated by a predetermined interval (e.g., hours, days, weeks, or months).

The terms initial dose, second line doses, and third line doses refer to the time sequence of administration. Thus, the initial dose is the dose that is administered at the beginning of the course of treatment (also called the initial dose); second line doses are doses that are administered after the initial dose; and third line doses are doses that are administered after the second line doses. All of the initial, second and third line doses may contain the same amount of antibody (anti-PD-1 or bispecific antibody). However, in certain embodiments, the amount contained in the initial, second, and third line doses differ from each other (eg, adjusted upwards or downwards as necessary) over the course of treatment. In certain embodiments, one or more (eg, 1, 2, 3, 4, or 5) doses are administered at the beginning of the course of treatment as loading doses, followed by doses that are administered less frequently (eg, maintenance doses). For example, an anti-PD-1 antibody can be administered to a patient with B cell cancer at a loading dose of about 1-3 mg/kg followed by one or more maintenance doses of about 0.1 to about 20 mg/kg. subject's body weight.

According to one illustrative embodiment of the present invention, each dose of the second and/or third line is administered through ^g /2-14 (for example, ¹ /2, 1, 1%, 2, 21/2, 3, 31/ ₂ , 4, 41/ 2, 5, 51/2, 6, 6 ^1/2 , 7, ^7g /2, 8, ^8g /2, 9, ^9g /2, 10, ^10g /2, 11, 11 ^1/2 , 12, 12 ^g /2, 13, 13 ^g /2, 14, 14 ^1/2 or more) weeks after the next

- 16 042623 of the previous dose. The phrase "next prior dose" as used herein means, in the case of a multiple dose sequence, the dose of anti-PD-1 antibody (and/or anti-CD20/CD3 bispecific antibody) administered to the patient prior to the next dose, in the case of a sequence with no intermediate doses.

Methods in accordance with this aspect of the present invention may involve administering any number of second and/or third doses of an anti-PD-1 antibody (and/or an anti-CD20/CD3 bispecific antibody) to a patient. For example, in certain embodiments, only one dose of the second line is administered to the patient. In other embodiments, the patient is administered two or more (eg, 2, 3, 4, 5, 6, 7, 8 or more) doses of the second line. Similarly, in certain embodiments, the patient is administered only one third-in-line dose. In other embodiments, the patient is administered two or more (eg, 2, 3, 4, 5, 6, 7, 8 or more) third dose doses.

In embodiments involving multiple second-line doses, each second-line dose may be administered at the same frequency as the other second-line doses. For example, each second line dose may be administered to a patient 1-2 weeks after the next prior dose. Similarly, in embodiments involving multiple third line doses, each third line dose may be administered at the same frequency as the other third line doses. For example, each third line dose may be administered to a patient 24 weeks after the next previous dose. Alternatively, the frequency with which second and/or third line doses are administered to a patient may vary over the course of treatment. The frequency of administration can also be adjusted by the physician during the course of treatment, depending on the needs of the individual patient participating in the clinical study.

In certain embodiments, one or more doses of the anti-PD-1 antibody and/or the anti-CD20/CD3 bispecific antibody are administered early in the course of treatment as initial doses more frequently (twice a week, once a week, or once every 2 weeks), with subsequent doses (fixing doses or maintenance doses) that are administered less frequently (for example, once every 4-12 weeks).

The present invention includes methods for sequentially administering an anti-PD-1 antibody in combination with an anti-CD20/CD3 bispecific antibody to a patient for the treatment of B-cell cancer (eg, non-Hodgkin's lymphoma, acute lymphoblastic leukemia). In some embodiments, the methods of the present invention comprise administering one or more doses of an anti-PD-1 antibody followed by one or more doses of an anti-CD20/CD3 bispecific antibody. In certain embodiments, the methods of the present invention comprise administering one dose of an anti-PD-1 antibody followed by one or more doses of an anti-CD20/CD3 bispecific antibody. In some embodiments, one or more doses of the anti-PD-1 antibody ranging from about 0.1 mg/kg to about 20 mg/kg may be administered followed by one or more doses of the bispecific antibody ranging from about 0.1 mg/kg. kg to about 10 mg/kg, to inhibit tumor growth and/or prevent tumor recurrence in a subject with B-cell malignancy. In some embodiments, the anti-PD1 antibody is administered at one or more doses followed by one or more doses of the bispecific antibody, resulting in increased antitumor efficacy (e.g., greater tumor growth inhibition, increased likelihood of preventing tumor recurrence compared to the subject). not subject to treatment, or a subject who was administered any of the antibodies as monotherapy). Alternative embodiments of the present invention relate to the parallel administration of an anti-PD-1 antibody and a bispecific antibody that is administered at a separate dose at the same or different frequency as compared to the anti-PD-1 antibody. In some embodiments, the bispecific antibody is administered before, after, or simultaneously with the administration of the anti-PD-1 antibody. In certain embodiments, the bispecific antibody is administered as a single dosage formulation with the anti-PD-1 antibody.

Dosage.

The amount of anti-PD-1 antibody and/or anti-CD20/CD3 bispecific antibody administered to a subject in accordance with the methods of the present invention is typically a therapeutically effective amount. As used herein, the phrase "therapeutically effective amount" means an amount of an antibody (an anti-PD-1 antibody or an anti-CD20/CD3 bispecific antibody) that provides one or more of the following: (a) reduction in the severity or duration of a symptom of B-cell cancer; (b) inhibiting tumor growth or increasing the degree of tumor necrosis, shrinkage and/or disappearance of the tumor; (c) retardation of tumor growth and development; (d) inhibiting or slowing down or stopping tumor metastasis; (e) preventing the recurrence of tumor growth; (f) improving the survival of a subject with a B-cell malignancy; and/or (g) reducing the use of, or reducing the need for, conventional antitumor therapy (eg, reducing or eliminating the use of chemotherapeutic or cytotoxic agents) compared to a subject not being treated or a subject administered any of the antibodies as monotherapy.

- 17 042623

In the case of an anti-PD-1 antibody, a therapeutically effective amount may be from about 0.05 mg to about 600 mg, for example, about 0.05 mg, about 0.1 mg, about 1.0 mg, about 1.5 mg, about 2.0 mg, approximately 10 mg, approximately 20 mg, approximately 30 mg, approximately 40 mg, approximately 50 mg, approximately 60 mg, approximately 70 mg, approximately 80 mg, approximately 90 mg, approximately 100 mg, approximately 110 mg, approximately 120 mg, approximately 130 mg, approximately 140 mg, approximately 150 mg, approximately 160 mg, approximately 170 mg, approximately 180 mg, approximately 190 mg, approximately 200 mg, approximately 210 mg, approximately 220 mg, approximately 230 mg, approximately 240 mg , approximately 250 mg, approximately 260 mg, approximately 270 mg, approximately 280 mg, approximately 290 mg, approximately 300 mg, approximately 310 mg, approximately 320 mg, approximately 330 mg, approximately 340 mg, approximately 350 mg, approximately 360 mg, approximately 370 mg, approximately 380 mg, approximately 390 mg, approximately 400 mg, approximately 410 mg, approximately 420 mg, approximately 430 mg, approximately 440 mg, approximately 450 mg, approximately 460 mg, approximately 470 mg, approximately 480 mg, approximately 490 mg , about 500 mg, about 510 mg, about 520 mg, about 530 mg, about 540 mg, about 550 mg, about 560 mg, about 570 mg, about 580 mg, about 590 mg, or about 600 mg anti-PD-1 antibody. In certain embodiments, 250 mg of an anti-PD-1 antibody is administered.

In the case of an anti-CD20/CD3 bispecific antibody, a therapeutically effective amount may be from about 10 micrograms (µg) to about 8000 µg, e.g., about 10 µg, about 20 µg, about 50 µg, about 70 µg, about 100 µg, about 120 µg , approximately 150 micrograms, approximately 200 micrograms, approximately 250 micrograms, approximately 300 micrograms, approximately 350 micrograms, approximately 400 micrograms, approximately 450 micrograms, approximately 500 micrograms, approximately 550 micrograms, approximately 600 micrograms, approximately 700 micrograms, approximately 900 micrograms, approximately 1000 micrograms, approximately 1050 micrograms, approximately 1100 micrograms, approximately 1500 micrograms, approximately 1700 micrograms, approximately 2000 micrograms, approximately 2050 micrograms, approximately 2100 micrograms, approximately 2200 micrograms, approximately 2500 micrograms, approximately 2700 micrograms, approximately 2800 micrograms , approximately 2900 μg, approximately 3000 μg, approximately 4000 μg, approximately 5000 μg, approximately 6000 μg, approximately 7000 μg, or approximately 8000 μg of an anti-CD20/CD3 bispecific antibody.

The amount of either anti-PD-1 antibody or anti-CD20/CD3 bispecific antibody contained in individual doses may be expressed in milligrams of antibody per kilogram of the subject's body weight (ie, mg/kg). In certain embodiments, any of the anti-PD-1 antibody or anti-CD20/CD3 bispecific antibody used in the methods of the present invention may be administered to a subject at a dose of from about 0.0001 to about 100 mg/kg of the subject's body weight. For example, the anti-PD-1 antibody can be administered at a dose of about 0.1 mg/kg to about 20 mg/kg of the subject's body weight. The anti-CD20/CD3 bispecific antibody can be administered at a dose of about 0.1 mg/kg to about 10 mg/kg of the subject's body weight.

Examples

The following examples are provided for the purpose of providing those skilled in the art with a complete disclosure and description of how to make and use the methods and compositions of the present invention and are not intended to limit the scope of what the present inventors consider to be their invention. Efforts have been made to ensure accuracy with respect to the values used (eg amounts, temperatures, etc.), however, some errors and deviations in experiments should be taken into account. Unless otherwise indicated, parts are parts by weight, molecular weight is average molecular weight, temperature is in degrees Celsius, and pressure is atmospheric or near atmospheric.

Example 1 In vivo efficacy of an anti-PD-1 antibody in combination with an anti-CD20xCD3 bispecific antibody against B16CD20 tumors.

In this example, the effect of blocking PD-1 in combination with CD20-targeted immunotherapy on established B16CD20 tumors in CD20 and CD3 humanized mice was studied using anti-mouse PD-1 antibodies and anti-human CD20xCD3 bispecific antibodies.

An exemplary CD20/CD3 bispecific antibody used in the examples herein is bsAb1 (also known as Antibody 1 disclosed in US 20150266966), a fully human anti-CD20 and CD3 bispecific monoclonal antibody, wherein the antibody contains a CD20-binding arm containing the first a heavy chain variable region (A-HCVR) containing the amino acid sequence of SEQ ID NO: 11; a light chain variable region (LCVR) containing the amino acid sequence of SEQ ID NO: 12; and a CD3 binding arm comprising a second heavy chain variable region (B-HCVR) comprising the amino acid sequence of SEQ ID NO: 13 and an LCVR comprising the amino acid sequence of SEQ ID NO: 12. light chains containing SEQ ID NO: 14-22.

CD20 and CD3 humanized mice were genetically engineered using VelociGene® technology (Valenzuela et al 2003, Nat. Biotechnol. 21:652-659), which were then bred to produce dual gene humanized CD20 CD3 mice (pub. U.S. Patent Application No. 14/949,834, filed November 23, 2015).

On day 7, mice were implanted subcutaneously with 2.5x105 B16_CD20 cells. On day 0, mice with mean tumor volumes ranging from 25 to 115 mm ³ were selected and randomized into five treatment groups. Mice were treated with antibodies twice a week as follows: group 1: control (PBS); group 2: isotype controls (bivalent human anti-irrelevant antigen and control rat IgG2a - BE0089 from BioXCell); group 3: anti-hCD20xCD3 antibody (bsAb1) (4 mg/kg); group 4: anti-mouse PD-1 antibody (10 mg/kg; RMPI-14_rIgG2a; BioXCell); and group 5: anti-hCD20xCD3 antibody (bsAb1) (4 mg/kg) + anti-mouse PD-1 antibody (10 mg/kg). All antibodies were administered intraperitoneally. In group 5 mice were treated with antibodies simultaneously. Tumor volume scores were monitored by caliper measurement twice a week throughout the experiment, and tumor-free animals were monitored for tumor recurrence for up to 80 days.

Antibodies to PD-1 and CD20xCD3 as monotherapy provided a delay in tumor growth in mice, and in mice the tumor volume reached 500 mm ³ on average for 19 days. In contrast, mice treated with anti-PD-1 antibody in combination with a bispecific anti-CD20xCD3 antibody achieved tumor volumes of 500 mm ³ on average in 27 days (FIG. 1 and Table 1).

Table 1. Tumor growth after administration of anti-PD-1 antibody and anti-CD20/CD3 bispecific antibody

Treatment Average number of days for which the tumor reaches 500 mm ³ The number of mice without tumors by day 30 PBS 15 0/7 Isotype controls 15 0/7 bsAbl 19 1/7 Antibody to PD-1 (rIgG2a) 19 1/7 bsAbl + anti-PD-1 antibody 27 4/7

Single agent and combination treatment did not induce any change in body weight, and no macroscopic signs of toxicity were observed in any of the treatment groups.

The experiment described above was repeated twice, and in both cases, treatment with the combination provided a significant delay and inhibition of tumor growth compared with controls or either anti-PD-1 antibody or anti-CD20/CD3 bispecific antibody monotherapy.

Example 2 In vivo efficacy of an anti-PD-1 antibody and an anti-CD20xCD3 bispecific antibody in a sequential dosing regimen.

In this example, the antitumor effect of an anti-mouse PD-1 antibody in combination with a bispecific anti-human CD20xCD3 antibody was studied using a sequential dosing regimen.

Bigene humanized mouse CD20 CD3s were genetically engineered using VelociGene® technology (Valenzuela et al 2003, Nat. Biotechnol. 21:652-659; U.S. Patent Application Publication No. 14/949834 filed November 23, 2015 ).

On day 7, mice were implanted subcutaneously with 2.5x105 B16_CD20 cells. On day 0, mice with mean tumor volumes of 30 to 65 mm ³ were selected and randomized into five treatment groups (FIG. 2). Throughout the study, tumor growth rates were measured using calipers and body weights were recorded twice a week. Mice were treated with antibodies by intraperitoneal injection twice a week as follows: group 1: control (PBS); group 2: isotype controls (bivalent human anti-irrelevant antigen and control rat IgG2a - BE0089 from BioXCell); group 3: anti-mouse PD-1 antibody (10 mg/kg; RMPI-14_rIgG2a; BioXCell); group 4: anti-hCD20xCD3 antibody (bsAb1) (4 mg/kg); group 5: anti-hCD20xCD3 antibody (bsAb1) (4 mg/kg) + anti-mouse PD-1 antibody (10 mg/kg) administered simultaneously; group 6: anti-mouse PD-1 antibody (10 mg/kg) followed by anti-hCD20xCD3 antibody (bsAb1) (4 mg/kg); and group 7: anti-hCD20xCD3 antibody (bsAb1) (4 mg/kg) followed by anti-mouse PD-1 antibody (10 mg/kg). All antibodies were administered intraperitoneally using a dosing regimen with sequential introduction, as shown in table. 2.

- 19 042623

Table 2. Dosing regimen with sequential administration

Gr. Component #1 Scheme dosing - component No. 1 Component #2 Scheme dosing - component No. 2 No. mice controls 1 Media carrier Base day 0.2 x/week Carrier medium Base day 0.2 x/week 5 2 isotypic control Base day 0.2 x/week isotypic control Base day 0.2 x/week 5 3 RMPI-14 (anti-PD-1 antibody) Base day 0.2 x/week N/A N/A 5 4 N/A N/A bsAbl Base day 0.2 x/week 6 Simultaneous dosing 5 RMPI-14 (anti-PD-1 antibody) Base day 0.2 x/week bsAbl Base day 0.2 x/week 7 Anti-PD-1 then bsAbl 6 RMPI-14 (anti-PD-1 antibody) Base day 0.2 x/week bsAbl Base day 7, 2 x/week 7 bsAbl, then anti-PD- 1 7 RMPI-14 (anti-PD-1 antibody) Base day 7, 2 x/week bsAbl Base day 0.2 x/week 7

Both co-dose of bsAb1 and anti-mouse PD-1 antibody, and dosed with anti-mPD-1 antibody followed by bsAb1 showed significant tumor growth delay compared to single-arm control antibodies (FIG. 3). When treated with the combination, when bsAb1 is administered starting at D0 and anti-PD-1 antibody is administered starting at D7, no tumor growth inhibition was observed compared to single agent treatment groups in the study. When the combination was administered, no difference in weight loss or non-tumor related mortality was observed.

Example 3 Clinical trial of anti-PD-1 antibody and anti-CD20xCD3 antibody in patients with B cell malignancies.

This study is an open-label, multicentre, dose escalation study with multiple dose escalation and expanded groups to provide data on the efficacy, safety, and tolerability of anti-PD-1 antibody and anti-CD20/CD3 bispecific antibody, alone and in combination, involving patients with B-cell malignancies (including B-cell non-Hodgkin's lymphoma, Hodgkin's lymphoma, and acute lymphoblastic leukemia).

An exemplary anti-PD-1 antibody used in this example is REGN2810 (also known as H4H7798N, disclosed in US 20150203579), a fully human anti-PD-1 monoclonal antibody containing a heavy chain containing the amino acid sequence of SEQ ID NO: 9, and a light chain containing the amino acid sequence of SEQ ID NO: 10; a pair of amino acid sequences HCVR/LCVR, providing SEQ ID NO: 1/2; and heavy and light chain CDR sequences provided for in SEQ ID NOs: 3-8.

An exemplary CD20/CD3 bispecific antibody used in this example is bsAb1 (described in Example 1 herein).

The primary study objective is to evaluate the safety, tolerability, and dose-limiting toxicity (DLT): (i) REGN2810 as a single agent in patients with lymphoma (B-cell non-Hodgkin's lymphoma [B-NHL] and Hodgkin's lymphoma [HL]); (ii) bsAb1 as a single agent in patients with acute lymphoblastic leukemia (ALL); (iii) combinations of bsAb1 and REGN2810 in patients with B-NHL; and (iv) combinations of bsAb1 and REGN2810 in patients with ALL.

The secondary objectives of the study are: (i) to determine the recommended dose for: REGN2810 as a single agent in patients with lymphoma (B-NHL and HL); bsAb1 as

- 20 042623 a separate agent in patients with ALL; bsAbl and REGN2810 given in combination in patients with BNHL; and bsAb1 and REGN2810 given in combination in patients with ALL; (ii) characterize the pharmacokinetic (PK) profile of bsAb1 and REGN2810 when administered alone and in combination; (iii) assess the immunogenicity of bsAb1 and REGN2810 when administered alone and in combination; and (iv) to pre-investigate the antitumor activity of bsAb1 and REGN2810 when administered as single agents in specific indications and in combination as measured by overall response rate, minimal residual disease (MRD) in patients with bone marrow disease at baseline, duration of response, survival progression-free, median survival, and percentage survival at 6 and 12 months.

Additional objectives are to evaluate biomarkers that may correlate with the mechanism of action, observed toxicity, and potential antitumor activity, including, without limitation, the following: cytokine profiling; assessment of B- and T-cell subpopulations in peripheral blood and immunophenotyping; assessment of changes in the level of gene expression in peripheral blood cells; and assessment of serum immunoglobulin.

Study population.

The target population includes patients with lymphoma (B-NHL and HL) and ALL for whom there are no standard treatments. The various pathological subtypes that meet the criteria for the different study groups are listed in Table 1. 3-5.

Table 3 Eligible Pathologic Subtype for WHO Lymphoma Treatment Groups: Upscaling REGN2810 as a Single Agent in B-NHL and HL Cohorts

Hodgkin's lymphoma (HL) • Classical HL in the form of nodular sclerosis • Classical HL with a large number of lymphocytes • Mixed cell classic HL • Classic HL with lymphoid depletion • Nodular HL variant with lymphoid predominance Neoplasms from mature B cells • Follicular lymphoma (FL) of any grade • Small cell lymphocytic lymphoma (SLL) • Lymphoplasmacytic lymphoma (LPL) • Marginal zone cell lymphoma (MZL) (splenic, nodal or extranodal) • Mantle cell lymphoma (MCL) • Diffuse large B-cell lymphoma (DLBCL), all subtypes • Diffuse large B-cell lymphoma (DLBCL), not specifically labeled • Large B-cell lymphoma with a large number of T-cells / histiocytes • DLBCL associated with chronic inflammation • Epstein-Barr virus (EBV)+ DLBCL in the elderly • Lymphomatoid granulomatosis • Primary mediastinal (thymic) Large cell lymphoma • Intravascular large B-cell lymphoma • Primary cutaneous DLBCL, type affecting the lower extremities • Unclassifiable B-cell lymphoma with mixed features of DLBCL and lymphoma

- 21 042623

Burkitt • Burkitt's lymphoma

Table 4. Pathological Subtype Eligible for WHO Lymphoma Treatment Groups: Expanded Cohorts Receiving REGN2810 as a Single Agent

Expansion of cohorts receiving REGN2810 as a single agent for Hodgkin's Lymphoma Expansion of cohorts receiving REGN2810 as a stand-alone agent in SILENT CD20+ B-NHL Expansion of cohorts receiving REGN2810 as a single agent for AGGRESSIVE CD20+ B-NHL • Classical HL in the form of nodular sclerosis • Classical HL with a large number of lymphocytes • Mixed cell classic HL • Classic HL with lymphoid depletion • Nodular HL variant with lymphoid predominance NEOPLASMA FROM MATURE B-CELLS • FL (degree 1 or 2) • Lymphoplasmacytic lymphoma (LPL) • MZL (splenic, nodal or extranodal) • Small cell lymphocytic lymphoma (SLL) NEOPLASMA FROM MATURE CELLS • FL (degree 3) • Mantle cell lymphoma (MCL) • DLBCL, all subtypes • DLBCL not specifically marked • B-large cell lymphoma with a large number of T cells/histocytes • DLBCL associated with chronic inflammation • Epstein-Barr virus (EBV)+ DLBCL in the elderly • Lymphomatoid granulomatosis • Primary mediastinal (thymic) • B-large cell lymphoma • Intravascular Large cell lymphoma • Primary dermal DLBCL, type, affecting the lower limbs • Unclassifiable B-cell lymphoma with mixed features of DLBCL and Burkitt's lymphoma • Burkitt's lymphoma

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Table 5 Eligible pathological subtype for WHO lymphoma treatment groups: bsAb1 and REGN2810 up-dose cohorts in combination and expanded cohorts

Combination dose escalation for CD20+ BNHL Expanding the cohort receiving the combination when SLOW CD20+ B-NHL Combination cohort expansion for AGGRESSIVE CD20+ B-NHL NEOPLASMA FROM MATURE B-CELLS Follicular lymphoma (FL) of any grade Small cell lymphocytic lymphoma (SLL) Lymphoplasmacytic lymphoma (LPL) Marginal zone cell lymphoma (MZL) (splenic, nodal or extranodal) Mantle cell lymphoma (MCL) Diffuse large cell lymphoma (DLBCL), all subtypes NEOPLASMA FROM MATURE B-CELLS FL (grade 1 or 2) Lymphoplasmacytic lymphoma (LPL) MZL (splenic, nodal or extranodal) Small cell lymphocytic lymphoma (SLL) NEOPLASMA FROM MATURE B-CELLS FL (degree 3) Mantle cell lymphoma (MCL) DLBCL, all DLBCL subtypes, not specifically labeled B-large cell lymphoma with a large number of T cells / histiocytes DLBCL associated with chronic inflammation Epstein-Barr virus (EBV) + DLBCL of the elderly Lymphomatoid

- 23 042623

Diffuse large B-cell lymphoma (DLBCL), not specifically labeled Large B-cell lymphoma with a large number of T cells / histiocytes DLBCL associated with chronic inflammation Epstein-Barr virus (EBV) + DLBCL of the elderly Lymphomatoid granulomatosis Primary mediastinal (thymic) large B-cell lymphoma Intravascular large B-cell lymphoma Primary cutaneous DLBCL, type affecting the lower extremities Unclassifiable B-cell lymphoma with mixed features of DLBCL and Burkitt's lymphoma Burkitt's lymphoma granulomatosis Primary mediastinal (thymic) large B-cell lymphoma Intravascular large B-cell lymphoma Primary cutaneous DLBCL, type affecting the lower extremities Unclassifiable B-cell lymphoma with mixed features of DLBCL and Burkitt's lymphoma Burkitt's lymphoma

Criteria for inclusion in the B-NHL and HL treatment groups.

To be eligible for inclusion in the study, a patient must meet the following criteria: (1) a hematopoietic malignancy characterized by: a) NHL: a confirmed CD20+ B cell malignancy where the disease in the active phase is refractory to the most recent prior therapy, or is followed by a relapse for which there are no standard treatments and for which anti-CD20 antibody treatment is not appropriate: i. B-NHL according to the WHO 2008 criteria (Campo 2011), b) confirmed HL according to the WHO 2008 criteria (Campo 2011), and in the disease in the active phase there is no response to previous therapy or there is a relapse after previous therapy for which there are no standard methods treatment (only for cohorts receiving REGN2810 therapy as a single agent); (2) all patients must have at least 1 bi-dimensional lesion (>1.5 cm) confirmed using diagnostic imaging (CT, PET-CT, or MRI); (3) age >18 years; (4) Eastern United Cancer Group (ECOG) functional status <1; (5) life expectancy of at least 6 months; (6) adequate bone marrow function, confirmed by the following criteria: a) platelet count >75x10 ⁹ /l, b) hemoglobin level >9 g/dl, c) ANC (absolute neutrophil count) >1x10 ⁹ /l (note: for patients with cell counts below the cut-off levels above should be considered for enrollment if, in the investigator's opinion, the cause is suspected to be related to recent bone marrow infiltration by a primary malignancy.In such cases, the investigator should discuss inclusion criteria with the sponsor and obtain approval for enrollment to the study in writing); (7) adequate liver function: a) total bilirubin <1.5x the upper limit of the normal range (ULN) (<3x the ULN, in liver disease), b) transaminases <2.5x the ULN (at < 5x higher than ULN, in liver disease), c) alkaline phosphatase <2.5x higher than ULN (in

- 24 042623 <5.0x exceeds ULN, with liver damage) (note: patients with liver damage due to their malignant neoplasm, while 3x excess of ULN<aspartate aminotransferase (AST) and / or <5x excess of ULN of alanine aminotransferase (ALT) and 1 5x ULN < total bilirubin < 3x ULN will be excluded Note: Patients with Gilbert's syndrome do not need to meet this requirement, provided their total bilirubin does not change from baseline Note: Patients with Gilbert's Syndrome are considered for inclusion study if, in the investigator's opinion, the abnormal laboratory results are related to the current primary malignancy, in which case the investigator should discuss inclusion criteria with the sponsor and obtain written approval for inclusion in the study); (8) serum creatinine <1.5x ULN or Cockcroft-Gault calculated creatinine clearance >50 ml/min. (Note: For patients with Cockcroft-Gault calculated creatinine clearance that does not meet the criteria, enrollment may be considered if measured creatinine clearance (based on 24-hour urine collection test or other appropriate method) >50 ml Note: Patients should be considered for enrollment if, in the investigator's opinion, abnormal laboratory results are related to their current primary malignancy. writing); (9) normal pre-treatment ejection fraction measured by MUGA scan or echocardiogram within 4 weeks prior to enrollment within the institution's normal range; (10) willingness to undergo mandatory pre-treatment biopsy if, in the opinion of the investigator, the patient has an accessible lesion from which to biopsy without significant risk to the patient; (11) willingness and ability to comply with requirements regarding clinic visits and procedures related to the study; and (12) providing a signed informed consent form.

Exclusion criteria for B-NHL and HL treatment groups.

A patient who meets any of the following criteria will be excluded from the study: (1) primary central nervous system (CNS) lymphoma or known or suspected CNS lesion in secondary CNS NHL; (2) history of or current significant CNS pathology such as: a) epilepsy, seizure, paresis, aphasia, apoplexy, severe brain injury, cerebellar disease, organic cerebral syndrome, psychosis, or b) evidence of foci of inflammation and / or vasculitis, determined by MRI of the brain during screening; (3) current or recent (within 2 years) evidence of significant autoimmune disease requiring treatment with systemic immunosuppressive therapies, which may suggest a risk of developing iAE; (4) standard anti-lymphoma chemotherapy (non-biological drugs) or radiation therapy less than 28 days before the first administration of the investigational drug(s); (5) treatment with an experimental agent other than a biological agent less than 28 days prior to the first administration of the investigational drug(s); (6) treatment with alemtuzumab less than 12 weeks from first administration of investigational drug(s); (7) treatment with rituximab, immunomodulatory agents, or other experimental or commercial non-biological agent less than 28 days prior to the first administration of the investigational drug(s). Examples of immunomodulatory agents include CTLA-4, 4-1BB (CD137), LAG3, OX-40 blockers, therapeutic vaccines or cytokine-based therapeutics; (8) previous allogeneic stem cell transplant; (9) prior treatment with an agent that blocks the PD-1/PD-L1 signaling pathway, unless the patient has a positive effect (only relevant for patients treated with REGN2810 as a standalone agent) (Note: such patients should be discussed with the sponsor's designated medical monitor prior to enrollment in the study); (10) concomitant active malignancy for which the patient is receiving treatment; (11) evidence of a significant comorbid illness or medical condition that may adversely affect the conduct of the study or place the patient at significant risk, including, without limitation, significant cardiovascular disease (e.g., New York City Class III or IV cardiovascular disease). cardiology associations, myocardial infarction within 6 months prior to screening, unstable arrhythmia or unstable angina) and/or significant lung disease (eg, obstructive pulmonary disease and history of symptomatic bronchospasm); (12) known active bacterial, viral, fungal, mycobacterial or other infection, or any significant case of infection requiring hospitalization or treatment with IV (intravenous) anti-infectives, within 14 days prior to first administration of study drug; (13) infection,

- 25 042623 caused by human immunodeficiency virus (HIV) or active infection caused by hepatitis B virus (HBV) or hepatitis C virus (HCV); (14) history of pneumonia in the past 5 years; (15) a history of allergic reactions attributed to compounds with a chemical or biological composition similar to that of the investigational drug(s); (16) a history of hypersensitivity reaction to any compound from the group of tetracycline antibiotics (a precautionary measure associated with the possible presence of trace components in the material for drug preparation); (17) a known hypersensitivity reaction to both allopurinol and rasburicase; (18) pregnant or breastfeeding women; and (19) a sexually active male or female of reproductive age who is unwilling to use appropriate contraception during the study and up to 6 months after stopping study drug.

Criteria for inclusion in the study groups with lymphoblastic leukemia.

To be eligible for study inclusion, a patient must meet the following criteria: (1) confirmed relapsed or refractory CD20+ (defined as flow cytometry-detected CD20 expression on >20% of leukemic lymphoblasts) B-cell ALL after at least induction and 1 cycle of fixing chemotherapy; A. Philadelphia-positive ALL patients require that at least 1 tyrosine kinase inhibitor fails or is intolerant to them; Note: Blast crisis patients with a lymphoid phenotype in chronic myeloid leukemia (CML) are eligible, provided they meet inclusion criterion #1; (2) age >18 years; (3) functional status on the ECOG scale <2; (4) non-CNS disease confirmed by lumbar puncture within 28 days of starting study drug (see 5); (5) adequate bone marrow function, confirmed by the following criteria: a) platelet count >10x10 ⁹ /l, b) Hb level >7 g/dl, c) absolute number of phagocytes >0.5x109/l (phagocytes: neutrophils, stab granulocytes and monocytes); (6) adequate liver function: a) total bilirubin <1.5x ULN (<3x ULN in liver disease), b) transaminases <2.5x ULN (<5x ULN, in liver disease) c) alkaline phosphatase <2.5x ULN (<5x ULN in liver disease) (Note: patients with Gilbert's syndrome do not need to meet this requirement, provided their total bilirubin does not change from baseline Note: Patients should be considered for enrollment if, in the Investigator's opinion, abnormal laboratory results are related to the current primary malignancy, In such cases, the Investigator should discuss eligibility criteria with the sponsor and obtain approval for enrollment in writing. ); (7) serum creatinine <1.5x ULN or Cockcroft-Gault calculated creatinine clearance >50 ml/min. (Note: For patients with Cockcroft-Gault calculated creatinine clearance that does not meet the criteria, enrollment may be considered if measured creatinine clearance (based on 24-hour urine collection test or other appropriate method) >50 ml Note: Patients should be considered for enrollment if, in the investigator's opinion, abnormal laboratory results are related to their current primary malignancy. written; (8) no evidence of acute or chronic graft-versus-host disease (GvHD) and no GvHD medication within 14 days prior to start of study drug(s); (9) normal pre-treatment ejection fraction measured by MUGA scan or echocardiogram within 4 weeks prior to enrollment within the institution's normal range; (10) willingness and ability to meet requirements regarding clinic visits and procedures related to the study; and (11) providing a signed informed consent form.

Exclusion criteria for treatment groups with lymphoblastic leukemia.

A patient who meets any of the following criteria will be excluded from the study: (1) a history of or current significant CNS pathology such as: a) epilepsy, seizure, paresis, aphasia, apoplexy, severe brain injury, disease cerebellum, organic cerebral syndrome, psychosis, or b) data on the presence of foci of inflammation and / or vasculitis, determined by MRI of the brain during screening; (2) Burkitt's leukemia; (3) current testicular lesion in leukemia; (4) current or recent (within 2 years) evidence of significant autoimmune disease (excluding GvHD) requiring treatment with systemic immunosuppressive therapies, which may suggest a risk of iAE; (5) standard anti-leukemic chemotherapy (non-biological agents) or radiotherapy less than 14 days prior to first administration of investigational drug(s)

- 26 042623 drug product(s); (6) treatment with an experimental agent other than a biological agent less than 14 days prior to the first administration of the investigational drug(s); (7) treatment with rituximab, immunomodulatory agents, or other experimental or commercial non-biological agent less than 14 days prior to the first study drug administration. (Examples of immunomodulatory agents include CTLA-4, 4-1BB (CD137), LAG3, OX-40 blockers, therapeutic vaccines, or cytokine-based therapeutics); (8) treatment with alemtuzumab less than 12 weeks prior to first administration of investigational drug(s); (9) prior allogeneic stem cell transplantation within 3 months of treatment; (10) concomitant active malignancy for which the patient is receiving treatment; (11) evidence of a significant comorbid illness or medical condition that may adversely affect the conduct of the study or place the patient at significant risk, including, without limitation, significant cardiovascular disease (e.g., New York City Class III or IV cardiovascular disease). cardiology associations, myocardial infarction within 6 months prior to screening, unstable arrhythmia or unstable angina) and/or significant lung disease (eg, obstructive pulmonary disease and history of symptomatic bronchospasm); (12) known active bacterial, viral, fungal, mycobacterial or other infection, or any significant case of infection requiring hospitalization or treatment with IV anti-infectives, within 14 days prior to first administration of investigational drug(s) ; (13) HIV infection or active HBV or HCV infection; (14) history of pneumonia in the past 5 years; (15) a history of allergic reactions attributed to compounds with a chemical or biological composition similar to that of the investigational drug(s); (16) a history of hypersensitivity reaction to any compound from the group of tetracycline antibiotics (a precautionary measure associated with the possible presence of trace components in the material for drug preparation); (17) a known hypersensitivity reaction to both allopurinol and rasburicase; (18) pregnant or breastfeeding women; and (19) a sexually active male or female of reproductive age who is unwilling to use appropriate contraception during the study and up to 6 months after stopping study drug.

Study design.

This study is an open label multicenter dose escalation study with multiple dose escalation and extended groups. Patients are assigned to one of the following groups: receiving REGN2810 as a single agent, receiving bsAb1 as a single agent, or receiving a combination of both drugs, depending on the patient's diagnosis and the stage of the study at the time of study entry.

Treatment groups and dosing cohorts for patients with lymphoma (B-NHL and HL) are described in more detail in FIG. 4. Patients are assigned to one of the following cohorts:

groups receiving REGN2810 as a single agent, in the case of patients with lymphoma (B-NHL and HL);

dose escalation cohorts (1 mg/kg and 3 mg/kg);

expanded cohorts: a) indolent B-NHL, b) aggressive B-NHL and c) HL groups treated with the combination, in the case of patients with B-NHL;

dose escalation cohorts for multiple regimens;

extended cohorts: a) indolent B-NHL, and b) aggressive B-NHL.

Single agent and combination treated cohorts for ALL patients are described in more detail in FIG. 5. Patients are assigned to one of the following cohorts:

groups receiving bsAb1 as a single agent, in the case of patients with ALL; dose escalation cohorts for multiple regimens;

expanded cohorts: a) relapsed/refractory ALL, and b) minimal residual disease positive (MRD+) ALL of the combination-treated groups in the case of patients with ALL;

dose escalation cohorts for multiple regimens.

expanded cohorts: a) relapsed/refractory ALL, and b) MRD positive ALL.

Combination therapy treatment is started after the individual product data has been submitted and reviewed by the appropriate health authority.

REGN2810 as a single agent in patients with lymphoma (B-NHL and HL).

In FIG. 6 shows a treatment regimen for REGN2810 as a single agent for patients with lymphoma. Patients are administered REGN2810 IV every 2 weeks (Q2W) at the established dose level (DL). Patients receive REGN2810 for a period of at least 12 doses (24 weeks) and no more than 24

- 27042623 doses (48 weeks). After at least 24 weeks of treatment, and after consultation with the investigator and sponsor, patients who had a complete response, disease stabilization, or partial response after tumor mass evaluations that remained unchanged through 3 subsequent tumor evaluations could also decide to discontinue treatment. After completion of treatment (24 or 48 weeks), a 24-week (6 month) follow-up period will be conducted.

bsAb1 as a single agent in patients with ALL.

In FIG. 7 shows a treatment regimen for bsAb1 as a single agent for patients with ALL. Patients are given a DL which will be an initial dose followed by a higher dose provided that the initial dose was tolerable (Table 6).

Table 6. Dose levels for bsAb1

Dose level Initial dose (fixed, mcg) Subsequent dose (fixed, mcg) DL-1 10 thirty DL1 thirty 100 DL2 100 300 DL3 300 1000 DL4 1000 2000 DL5 1000 3000 DL6 1000 4000 DL7 1000 5000

bsAb1 was administered intravenously every week for a period of 11 doses, followed by treatment every 4 weeks (Q4W) starting at week 13 for a further 6 doses. Patients are followed up for an additional 6 months after completion of bsAb1 treatment.

Combined therapy.

Includes 2 separate groups receiving the combination, one for patients with B-NHL and the other for patients with ALL. In FIG. 8 shows a combination treatment regimen for patients with B-NHL, and FIG. 9 shows a combination treatment regimen for patients with ALL.

Patients are administered REGN2810 IV Q2W at the established DL (0.3, 1, or 3 mg/kg). Patients receive REGN2810 for a period of at least 12 doses (24 weeks) and no more than 24 doses (48 weeks). After at least 24 weeks of treatment, and after consultation with the investigator and sponsor, patients who had a complete response, disease stabilization, or partial response after tumor mass evaluations that remained unchanged through 3 subsequent tumor evaluations could also decide to discontinue treatment.

Patients will be assigned to DL bsAb1, which will provide an initial dose, followed by a higher dose, provided that the initial dose was tolerated (Table 6). bsAbl will be administered intravenously every week for a period of 11 doses, followed by Q4W treatment starting at week 13 for a period of 6 more doses.

For study visits where both bsAb1 and REGN2810 are administered, REGN2810 will be administered first. Patients will be followed up for at least another 6 months after completion of bsAb1 treatment. The timing of follow-up will depend on the duration of treatment for the REGN2810 patient (24 or 48 weeks).

initial doses.

REGN2810 as a standalone agent: The initial dose of REGN2810 in patients with lymphoma is 1 mg/kg once every 2 weeks, in the absence of unexpected safety findings. Cohort extensions for REGN2810 as a single agent in indolent B-NHL, aggressive B-NHL and HL are determined in the dose escalation group of REGN2810 as a single agent in patients with lymphoma (B-NHL and HL).

bsAb1 as a stand-alone agent: Baseline DL of bsAb1 as a stand-alone agent in patients with ALL is established based on safety observations. The initial dose of initial DL in patients with ALL will be at least 10 less than the initial dose of DL for which safety has been confirmed; however, the baseline DL will not be lower than the DLL. Cohort expansions for bsAb1 as a single agent in relapsed/refractory ALL and MRD positive ALL are determined in the ALL escalation group.

Combination Group - B-NHL Patients: The planned dose of REGN2810 when given in combination with bsAb1 in B-NHL patients is 3mg/kg Q2W, assuming no unexpected safety study results in case of dose escalation of REGN2810 as a single agent in malignant neoplasms from B-cells. The baseline DL of bsAb1 when given in combination with REGN2810 in patients with B-NHL will be 1 DL less than that which has been shown to be safe and not less than DL1.

- 28 042623

Combination Group - ALL Patients: The planned dose of REGN2810 when given in combination with bsAb1 in ALL patients is 3mg/kg Q2W, assuming there are no unexpected safety results from dose escalation of REGN2810 as a single agent in B malignancies -cells. The baseline DL of bsAb1 when administered in combination with REGN2810 in ALL patients will be the DL that has been shown to be safe and minimally bioactive in the bsAb1 escalation group as a single agent in ALL patients in the current study. Minimal bioactivity is defined as evidence of a 50% reduction in bone marrow blasts (partial response) in a week 5 bone marrow study in at least 1 of 3 patients treated at the established dose level.

Dose increase.

In all groups and all cohorts, the escalation rules will follow the classic 3+3 dose escalation scheme of 3 to 6 patients per cohort.

The dose-limiting toxicity follow-up period (DLT) is defined as the first 28 days of treatment for all cohorts in all groups. Any of the following events occurring in the first 28 days of treatment (and considered by the investigator as such to be related to study treatment) are considered DLTs: grade >2 uveitis, grade 4 neutropenia, grade 4 thrombocytopenia, and grade >3 febrile neutropenia.

The maximum tolerated dose (MTD) is determined based on observed toxicity during the DLT observation period and is defined as the dose level (DL) immediately below the level at which dosing is stopped due to DLT in 2 or more patients. If, for a portion of the group, dose escalation is not discontinued due to DLT, the MTD will be considered not to have been determined.

The optimal biological dose is also determined based on the results of observations of safety and tolerability, PK, PD and preliminary data on antitumor activity.

The recommended dose for expanded groups is determined based on a review of the data used to determine the MTD and/or optimal biological dose.

MTD, optimal biological dose and recommended dose are determined independently for groups receiving a single agent, and each group receiving a combined therapeutic drug for certain indications (NHL and ALL); up to 4 MTDs, optimal biological doses and recommended doses can be identified. The MTD for any of the combination therapy groups does not exceed the DL MTD of the single agent, since the cases of DLT in 2 patients for such a DL of the individual agent, and the resulting definition of MTD, preclude further dose increases.

Study duration.

The study treatment period is between 6 and 12 months, depending on individual patient response data. The follow-up period is 6 months for all patients.

Sample size: The exact number of patients included in the study depends on the cases of protocol-defined DLTs and the number of DLs that will be available. The sample size for dose escalation of REGN2810 as a single agent for lymphoma (B-NHL and HL) is 12 patients or less. The sample size for bsAb1 as a single agent in the case of patients with ALL is no more than 42 patients (depending on which DL is available in this group). The sample size for increasing the dose of the combination drug in the case of patients with B-NHL is no more than 42 patients (depending on which DL is available in this group). The sample size for increasing the dose of the combination drug in the case of patients with ALL is no more than 42 patients (depending on which DL is available in this group). Each expanded cohort will include 20 patients, for a total of 180 patients.

Investigated treatment options and administration.

bsAb1 is provided as a solution in sterile single use vials. Each vial contains bsAb1 in a 1 ml extractable volume at a concentration of 2 mg/ml. A pharmacist or other qualified person is designated at each center to prepare bsAb1 for administration. The amount of dose(s) received corresponds to the prescribed dose level for the cohort. The dose administered at each dose level is a fixed dose and is independent of the patient's weight or body surface area. Each dose of bsAb1 is administered by intravenous (IV) infusion over at least 60 minutes. The duration of the infusion may be extended up to 4 hours according to clinical judgment by the attending physician. In addition, the investigator may decide to divide the dose into 2 separate infusions administered over a period of 2 (preferably consecutive) days.

REGN2810 is provided as a solution in sterile single use vials. Each vial contains REGN2810 at a concentration of 25 mg/ml in a volume sufficient to extract 10 ml. REGN2810 will be given as a 30 minute IV infusion. The dose for each patient will depend on the individual body weight. The dose of REGN2810 should be adjusted according to changes in body weight of >10%. Dose adjustments according to changes in body weight of <10% are at the discretion of the investigator.

For study visits where both bsAb1 and

REGN2810, REGN2810 is entered first.

Dexamethasone premedication is required prior to administration of bsAb1 at doses of 300 μg or greater at least 1 hour prior to infusion. In the case of the first administration of the initial dose of bsAb1 and the first administration of a subsequent higher dose (stepped dose), at least 7.5 mg of dexamethasone is recommended. If the patient tolerates infusions without any signs or symptoms of an infusion reaction or cytokine release syndrome (CRS), the investigator may consider reducing the dose or withdrawing dexamethasone premedication prior to subsequent infusions, as determined by clinical judgement. Premedication with antihistamines and/or acetaminophen may also be considered. At doses of bsAb1 below 300 mcg, empiric premedication with antihistamines, acetaminophen, and/or corticosteroids prior to investigational drug infusion is not recommended unless the patient has experienced an infusion reaction or CRS of grade 2 or higher caused by a previous bsAb1 infusion.

It is recommended that patients with ALL who are at high risk for developing cytokine release syndrome (CRS) and/or TLS (defined as: >50% lymphoblasts in the bone marrow; lactate dehydrogenase [LDH] >500 U/L; or extramedullary disease) received dexamethasone as part of the preparatory phase of therapy. The concentration of dexamethasone as part of the preparatory phase of therapy should be 10 mg/m ² every day (QD) for a minimum of 3 days and a maximum of 5 days. The use of dexamethasone as part of the preparatory phase of therapy should be discontinued > 72 hours before the start of the drug(s) product(s).

Patients with relapse or progression may be considered for re-treatment. For patients with a suboptimal response, retreatment may also be considered. The choice of retreatment (addition of REGN2810, bsAb1, or the treatment the patient is already receiving at a higher dose) will depend on the initial treatment the patient received in the trial (e.g., bsAb1 alone, REGN2810, or combination therapy), and which cohorts were proven safe at the time the patient was considered for retreatment. All retreatment decisions will be made following discussion between the treating investigator and the sponsor. Re-treatment will be at the highest DL considered safe and tolerable at the time of relapse or progression. Prior to retreatment, patients will be required to re-sign the informed consent form and that they meet the inclusion criteria for retreatment studies. In the case of patients who have been treated with a single agent, if the treating physician believes that, in the event of relapse or progression, it is in the best interest of the patient to receive combination therapy, the patient may switch to treatment with the combination at a dose level of the combination that was considered safe and tolerable at the time the patient the possibility of re-treatment was considered.

Study endpoints.

The primary endpoint is safety (particularly adverse events [AE], DLT, safety laboratory data, and clinical trial results). Secondary endpoints are: (i) PK bsAb1 and REGN2810 when administered alone and in combination; (ii) immunogenicity: antibodies to bsAb1 and/or to REGN2810; (iii) antitumor activity: (a) overall response rate according to the relevant response criteria for a particular indication; (b) duration of response and progression-free survival at 6 and 12 months; (c) assessment of minimal residual disease (MRD) for patients with bone marrow involvement at baseline; and (iv) pharmacodynamic measurements, including cytokine profiling; evaluation of subpopulations of B and T cells in peripheral blood and immunophenotyping, analysis of PD-1 occupancy of circulating T cells, evaluation of changes in the level of gene expression in peripheral blood cells; and assessment of serum immunoglobulin.

The percentage change in target tumor size from baseline was also noted and reported in the summary.

Procedures and assessments.

Screening procedures that need to be performed include assessment of the ejection fraction of the heart and MRI of the brain.

Safety assessment procedures include history of previous medical history, physical examination, assessment of vital signs, electrocardiogram (ECG), coagulation analysis, immunological safety tests (for patients treated

- 30 042623

REGN2810), evaluation of B-symptoms and functional status, clinical laboratory studies, AE and evaluation for concomitant medications.

Efficacy analysis procedures required for tumor evaluations include CT or MRI scan, 18F-fluorodeoxyglucose positron emission tomography (FDG-PET), bone marrow puncture and biopsy (BMA/Bx), lumbar puncture, biopsy lymph node and/or tumor.

NHL and HL patients are evaluated according to the Cheson criteria (Cheson et al 2007, J. Clin. Oncol. 25(5):579-86). Patients with fluorodeoxyglucose (FDG) accumulation disease are also evaluated according to the Lugano classification (Cheson et al 2014, J. Clin. Oncol 32:3059-3067). Patients with ALL are evaluated according to the NCCN Guidelines 2014.

Evaluation for the presence of MRD using bone marrow samples is carried out centrally using polymerase chain reaction (PCR). Response determination for MRD is performed according to Bruggemann et al (Leukemia 2010, 24:521-35) in patients with ALL, follicular lymphoma and marginal zone cell lymphoma.

Collect blood samples for evaluation of PK and antibodies to the drug (ADA).

Biomarker samples are collected to monitor changes in cytokine production, serum levels of pro-inflammatory cytokines, and changes in lymphocyte subpopulations and their activation status. In addition, these samples allow for tumor assays or somatic cell genetic assays for variations that affect the clinical course of the primary disease or modulate treatment-induced side effects.

Safety.

An adverse event (AE) is any adverse medical event in a patient administered an investigational drug that may or may not have a causal relationship with the investigational drug. Thus, an AE is any adverse and unintended sign (including abnormal laboratory findings), symptom, or disease that coincides in time with the use of an investigational medicinal product, whether or not thought to be related to the investigational medicinal product. AE also includes any worsening (i.e., any clinically significant change in frequency and/or intensity) of a pre-existing condition that coincides in time with study drug use. Progression of a primary malignant neoplasm will not be considered an AE if it is clearly consistent with the typical scenario of primary malignant tumor progression (including dynamics, affected organs, etc.). Clinical symptoms of progression may be recorded as AEs if the symptom cannot be identified solely as being related to the progression of the primary malignancy, or does not match the expected progression scenario for the disease under study. Serious AE (SAE) is any adverse medical event that, at any dose, is fatal, life-threatening, requires hospitalization, results in permanent or significant disability, and/or is a medically significant event.

Patients are monitored for vital signs, general safety, development of cytokine release syndrome, B-cell depletion, CNS toxicity, and immune-mediated AEs.

Statistical analysis plan.

Dose escalation cohorts: The study design is based on the traditional 3+3 regimen with 3-6 patients per DL.

Expanded Cohorts: The sample size of 20 patients for each expanded cohort was determined based on clinical considerations to further investigate the safety of RP2D in expanded cohorts. The sample size of 20 patients also makes it possible to pre-evaluate the response of the tumor.

All registered AEs in this study are classified using the currently available version of the Medical Dictionary for Regulatory Activities (MedDRA®). The classification is represented by terms in the direction from the lowest level. Shorthand, Preferred Terms (PT), and Major System Organ Class (SOC) are provided.

Brief descriptions of post-treatment adverse events (TEAEs), by treatment group, include: (i) number (n) and percentage (%) of patients with at least 1 TEAE on SOC and RT; (ii) TEAE by severity reported by SOC and RT; and (iii) TEAE for relationship to treatment (associated or not) reported by SOC and RT. Deaths and other serious adverse events (SAEs) are listed and summarized by treatment group. Adverse events that occurred after the start of treatment, which are the reason for the final discontinuation of treatment, are listed and summarized by treatment groups.

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Performance analyses.

The summary data indicates the objective response of the tumor, determined according to the criteria in accordance with a particular disease. Data on duration of response and progression-free survival at 6 and 12 months are summarized and summarized according to the Kaplan-Meier assessment, if necessary. The status regarding the minimum residual disease is given and indicated in the summary data. Data on progression-free survival are presented and summarized. Data on the percentage change in target tumor size from baseline are also summarized.

Results.

The antibodies, alone and in combination, are expected to be safe and well tolerated by patients. Administration of REGN2810 alone or in combination with bsAb1 is expected to provide tumor growth inhibition and/or promote tumor regression in patients with indolent or aggressive B-NHL or HL. ALL patients treated with bsAb1 alone or in combination with REGN2810 are expected to experience tumor growth inhibition and/or remission. It is expected that the overall response rate will exceed that of the combination therapeutic drug compared with any of the drugs as monotherapy.

The scope of the present invention is not limited to the specific embodiments described herein. In fact, various modifications of the present invention in addition to those described herein will be apparent to those skilled in the art from the foregoing description and the accompanying drawings. Such modifications are intended to be covered by the scope of the appended claims.

Claims (33)

1. A method of treating or inhibiting tumor growth, comprising (i) selecting a subject with B-cell non-Hodgkin's lymphoma; and (ii) administering to the subject a therapeutically effective amount of an antibody or antigen-binding fragment thereof that specifically binds programmed cell death protein-1 (PD-1); and a therapeutically effective amount of a bispecific antibody comprising a first antigen-binding arm that specifically binds CD20 and a second antigen-binding arm that specifically binds CD3; wherein the anti-PD-1 antibody or antigen-binding fragment thereof comprises three heavy chain variable region (HCVR) complementarity-determining regions (CDRs) (HCDR1, HCDR2 and HCDR3) containing the amino acid sequence of SEQ ID NO: 1 and three light chain CDRs ( LCDR1, LCDR2 and LCDR3) light chain variable region (LCVR) containing the amino acid sequence of SEQ ID NO: 2; The first antigen-binding arm of the bispecific antibody contains three heavy chain variable region (A-HCVR) heavy chain CDRs (A-HCDR1, A-HCDR2 and A-HCDR3) containing the amino acid sequence of SEQ ID NO: 11 and three light chain CDRs (LCDR1). , LCDR2 and LCDR3) LCVR containing the amino acid sequence of SEQ ID NO: 12; the second antigen-binding arm of the bispecific antibody contains three heavy chain CDRs (B-HCDR1, B-HCDR2 and B-HCDR3) of the heavy chain variable region (B-HCVR) containing the amino acid sequence of SEQ ID NO: 13, and three light chain CDRs (LCDR1, LCDR2 and LCDR3) LCVR containing the amino acid sequence of SEQ ID NO: 12; and the amount of the anti-PD-1 antibody or antigen-binding fragment thereof is 1-3 mg/kg of the subject's body weight, the amount of the bispecific antibody is 10 to 8000 μg, and the anti-PD-1 antibody or antigen-binding fragment thereof is administered before or simultaneously with the bispecific antibody. 2. The method of claim 1, wherein the amount of the anti-PD-1 antibody is 1 or 3 mg/kg of the subject's body weight. 3. The method according to any one of claims 1, 2, wherein the anti-PD-1 antibody is administered simultaneously with the bispecific antibody. 4. The method of claim 3, wherein the anti-PD-1 antibody is administered prior to the administration of the bispecific antibody. 5. The method of claim 4, wherein the anti-PD-1 antibody is administered 1 week prior to administration of the bispecific antibody. 6. The method of claim 1, wherein one or more doses of the anti-PD-1 antibody are administered in combination with one or more doses of the bispecific antibody. 7. The method of claim 6, wherein each dose of the anti-PD-1 antibody is 1-3 mg/kg of the subject's body weight. 8. The method of claim 6 or 7, wherein each dose of the anti-PD-1 antibody is 1 or 3 mg/kg of the subject's body weight. 9. The method of any one of claims 6-8, wherein each dose of the bispecific antibody is 108,000 micrograms. 10. The method of any one of claims 6-9, wherein each dose of anti-PD-1 antibody is administered 0.5 to 12 weeks after the next previous dose. - 32 042623 11. The method according to any one of claims 6-10, in which each dose of the bispecific antibody is administered through 0.5-12 weeks after the next previous dose. 12. The method of claim 11, wherein each dose of anti-PD-1 antibody is administered once every two weeks and each dose of the bispecific antibody is administered once a week. 13. The method of any one of claims 6-12, wherein each dose of the bispecific antibody is divided into 2-5 portions within a dosing period. 14. The method of any one of claims 6 to 13, wherein the anti-PD-1 antibody is administered prior to or concurrently with the administration of the bispecific antibody. 15. The method of claim 14 wherein the anti-PD-1 antibody is administered prior to the administration of the bispecific antibody. 16. The method of claim 15, wherein the anti-PD-1 antibody is administered 1 week prior to administration of the bispecific antibody. 17. The method according to any one of claims 1 to 16, wherein the antibodies are administered intravenously, subcutaneously, or intraperitoneally. 18. The method according to any one of claims 1 to 17, wherein the subject shows resistance, or an unsatisfactory response, or relapse after prior therapy. 19. The method of any one of claims 1 to 18, wherein the treatment provides a therapeutic effect selected from the group consisting of tumor growth inhibition, tumor cell reduction, tumor regression, survival enhancement, partial response, and complete response. 20. The method of claim 19, wherein tumor growth is delayed by at least 10 days compared to a non-treated subject. 21. The method of any one of claims 1 to 20, wherein tumor growth is inhibited by at least 50% compared to a non-treated subject. 22. The method of any one of claims 1 to 20, wherein tumor growth is inhibited by at least 50% compared to a subject treated with any of the antibodies as monotherapy. 23. The method of claim 14, wherein tumor growth is inhibited by at least 50% compared to a subject treated with the anti-CD20/CD3 bispecific antibody prior to administration of the anti-PD-1 antibody. 24. The method according to any one of claims 1 to 23, further comprising administering to the subject a third therapeutic agent or therapy, where the third therapeutic agent or therapy is selected from the group consisting of radiation, surgery, chemotherapeutic agent, antitumor vaccine, PD-L1 inhibitor , LAG-3 inhibitor, CTLA-4 inhibitor, TIM3 inhibitor, BTLA inhibitor, TIGIT inhibitor, CD47 inhibitor, indolamine 2,3-dioxygenase (IDO) inhibitor, vascular endothelial growth factor (VEGF) antagonist, angiopoietin-2 (Ang2) inhibitor ), inhibitor of transforming growth factor beta (TGFe), inhibitor of epidermal growth factor receptor (EGFR), antibody to tumor-specific antigen, Bacillus Calmette-Guerin vaccine, granulocyte-monocytic colony-stimulating factor, cytotoxin, inhibitor of interleukin 6 receptor (IL-6R) , an interleukin 4 receptor (IL-4R) inhibitor, an IL-10, IL-2, IL-7, IL-21, IL-15 inhibitor, an antibody-drug conjugate, an anti-inflammatory drug, and a dietary supplement. 25. The method according to claim 1, in which HCDR1 contains the amino acid sequence of SEQ ID NO: 3; HCDR2 contains the amino acid sequence of SEQ ID NO: 4; HCDR3 contains the amino acid sequence of SEQ ID NO: 5; LCDR1 antibodies to PD-1 or its antigennegative fragment contains the amino acid sequence of SEQ ID NO: 6; LCDR2 antibodies to PD-1 or its antigennegative fragment contains the amino acid sequence of SEQ ID NO: 7; and LCDR3 of an anti-PD-1 antibody or antigen binding fragment thereof comprises the amino acid sequence of SEQ ID NO: 8. 26. The method of claim 25 wherein the HCVR comprises the amino acid sequence of SEQ ID NO: 1 and the LCVR comprises the amino acid sequence of SEQ ID NO: 2. 27. The method of any one of claims 1 to 26, wherein the anti-PD-1 antibody comprises a heavy chain comprising the amino acid sequence of SEQ ID NO: 9 and a light chain comprising the amino acid sequence of SEQ ID NO: 10. 28. The method according to claim 1, in which A-HCDR1 contains the amino acid sequence of SEQ ID NO: 14; A-HCDR2 contains the amino acid sequence of SEQ ID NO: 15; A-HCDR3 contains the amino acid sequence of SEQ ID NO: 16; The LCDR1 of the first antigen-binding arm of the bispecific antibody contains the amino acid sequence of SEQ ID NO: 17; The LCDR2 of the first antigen-binding arm of the bispecific antibody contains the amino acid sequence of SEQ ID NO: 18; and LCDR3 of the first antigen-binding arm of the bispecific antibody contains the amino acid sequence of SEQ ID NO: 19. 29. The method of claim 28, wherein the A-HCVR comprises the amino acid sequence of SEQ ID NO: 11 and the LCVR of the first antigen-binding arm of the bispecific antibody comprises the amino acid sequence of SEQ ID NO: 12. 30. The method of claim 1, wherein the B-HCDR1 contains the amino acid sequence of SEQ ID NO: - 33 042623 20; B-HCDR2 contains the amino acid sequence of SEQ ID NO: 21; B-HCDR3 contains the amino acid sequence of SEQ ID NO: 22; The LCDR1 of the second antigen-binding arm of the bispecific antibody contains the amino acid sequence of SEQ ID NO: 17; The LCDR2 of the second antigen-binding arm of the bispecific antibody contains the amino acid sequence of SEQ ID NO: 18; and LCDR3 of the second antigen-binding arm of the bispecific antibody contains the amino acid sequence of SEQ ID NO: 19. 31. The method of claim 30, wherein the B-HCVR comprises the amino acid sequence of SEQ ID NO: 13 and the LCVR of the second antigen-binding arm of the bispecific antibody comprises the amino acid sequence of SEQ ID NO: 12. 32. The use of a therapeutically effective amount of an isolated antibody or an antigen-binding fragment thereof that specifically binds programmed cell death protein-1 (PD-1), in combination with a therapeutically effective amount of an isolated bispecific antibody containing a first antigen-binding arm that specifically binds CD20, and a second antigen-binding arm that specifically binds CD3 for treating or inhibiting the growth of a B-cell cancer in a subject, wherein: the anti-PD-1 antibody or antigen-binding fragment thereof comprises three heavy chain variable region (HCVR) complementarity determining regions (CDRs) (HCDR1, HCDR2 and HCDR3) containing the amino acid sequence of SEQ ID NO: 1 and three light chain CDRs (LCDR1 , LCDR2 and LCDR3) light chain variable region (LCVR) containing the amino acid sequence of SEQ ID NO: 2; the first antigen-binding arm of the bispecific antibody contains three heavy chain CDRs (A-HCDR1, A-HCDR2 and A-HCDR3) of the heavy chain variable region (A-HCVR) containing the amino acid sequence of SEQ ID NO: 11, and three light chain CDRs (LCDR1, LCDR2 and LCDR3) LCVR containing the amino acid sequence of SEQ ID NO: 12; the second antigen-binding arm of the bispecific antibody contains three heavy chain CDRs (B-HCDR1, B-HCDR2 and B-HCDR3) of the heavy chain variable region (B-HCVR) containing the amino acid sequence of SEQ ID NO: 13, and three light chain CDRs (LCDR1, LCDR2 and LCDR3) LCVR containing the amino acid sequence of SEQ ID NO: 12, and the amount of the anti-PD-1 antibody or antigen-binding fragment thereof is 1-3 mg/kg of the subject's body weight, and the amount of the bispecific antibody is from 10 to 8000 μg. 33. Use according to claim 30, wherein the B-cell malignant tumor is selected from the group consisting of Hodgkin's lymphoma, non-Hodgkin's lymphoma, follicular lymphoma, small cell lymphocytic lymphoma, lymphoplasmacytic lymphoma, marginal zone cell lymphoma, mantle zone cell lymphoma, diffuse B -large cell lymphoma, B-cell forms of lymphoma, lymphomatoid granulomatosis, Burkitt's lymphoma, acute lymphoblastic leukemia, hairy cell leukemia and B-cell chronic lymphocytic leukemia.