Dosing regimens for combination therapy targeting DLL3 and PD-1

Abstract

The present invention provides a method of treating DLL3-positive cancer or SCLC, comprising administering to a subject in need thereof an anti-DLL3 agent and an anti-PD-1 antibody. Stepwise administration of the anti-DLL3 agent is also disclosed.

Description

[Technical field]

[0001] Priority This application claims the benefit of U.S. Provisional Patent Application No. 63 / 186,569, filed May 10, 2021, the contents of which are incorporated by reference herein in their entirety.

[0002] Submission of sequence listings in ASCII text files The contents of the following ASCII text file submission are incorporated by reference in their entirety into this specification: Sequence Listing in Computer Readable Format (CRF) (Filename: A-2789-WO01-SEC_Sequence Listing_ST25, Data Creation Date: May 6, 2022, Size: 123,163 bytes).

[0003] This application relates to the dosage and administration of combination therapies targeting DLL3 and PD-1 for the treatment of cancer. [Background technology]

[0004] Delta-like 3 (DLL3) is a type 1 transmembrane protein and non-canonical Notch ligand. DLL3 is a promising target for the development of T cell therapy due to its high cell surface expression in neuroendocrine tumors and minimal, mainly cytoplasmic localization in normal tissues (Owen et al., J Hematol Oncol., 12:61 (2019)). Small cell lung cancer (SCLC) is a neuroendocrine cancer in which DLL3 is differentially expressed. Using immunohistochemistry (IHC), 85% of SCLC tumors stained positive for DLL3 in a pattern consistent with both membrane and cytoplasmic expression. In contrast, low levels of DLL3 protein expression were detected in normal brain, pancreatic islets, and pituitary gland with a cytoplasmic staining pattern (Saunders et al., Sci Transl Med. 7:302ra136 (2015)).

[0005] SCLC is an aggressive form of lung cancer with poor prognosis and limited treatment options, accounting for approximately 10-15% of lung cancers. Survival rates have remained low for decades, with only 5% of SCLC patients surviving 5 years, largely due to the lack of new therapies to combat this form of lung cancer. SCLC is characterized by neuroendocrine differentiation, high proliferation rates, rapid doubling times, and early establishment of widespread metastatic lesions. Approximately one-third of patients present with limited-stage disease. Most patients present with extensive-stage disease, defined as tumor in only one breast and contained within a single radiation field. These stages influence the available treatment regimens, limiting which stages are treated with chemotherapy and radiation, and which are treated with chemotherapy alone.

[0006] Patients with SCLC typically respond well to current state-of-the-art treatments, including etoposide and cisplatin, but invariably relapse with chemotherapy-resistant disease for which there are currently no available treatment options. The prognosis in the relapsed, refractory setting is very poor, with rapidly progressing disease and a short median survival of less than six months. Patients with extensive-stage SCLC develop drug resistance and die as a result of their disease at a median time of 10-12 months from diagnosis.

[0007] AMG757 is a bispecific T cell engager (BiTE®) molecule that targets DLL3 on cancer cells and CD3 on T cells. It was developed for the treatment of neuroendocrine cancers such as SCLC. AMG757 is being evaluated in clinical trials to treat SCLC.

[0008] Pembrolizumab (Keytruda®) and nivolumab (Opdivo®) are antibodies against programmed cell death-1 (PD-1). Both are approved in the United States for the treatment of patients with metastatic SCLC who have progressed after platinum-based chemotherapy and at least one other therapy. However, approval was based on relatively low response rates (19% for pembrolizumab and 12% for nivolumab). Studies evaluating nivolumab as second-line or maintenance therapy have not met their primary endpoints (Reck et al., Annals of Oncology. 29:x39-x43 (2018)). Summary of the Invention [Problem to be solved by the invention]

[0009] There is an unmet medical need for the development of therapeutics for the treatment of SCLC. [Means for solving the problem]

[0010] Based on the disclosure provided herein, those of ordinary skill in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the invention described herein, which equivalents are intended to be encompassed by embodiment (E) below.

[0011] E1: A method for treating DLL3-positive cancer, comprising administering an anti-DLL3 agent and an anti-PD-1 antibody to a subject in need thereof, wherein the anti-DLL3 agent is administered at a dose of 0.3 mg to 30 mg, or 3 mg to 100 mg, once every two weeks, and the anti-PD-1 antibody is administered at a dose of 480 mg, once every four weeks.

[0012] E2: A method of treating a DLL3 positive cancer comprising administering to a subject in need thereof an anti-DLL3 agent and an anti-PD-1 antibody, wherein the anti-DLL3 agent is administered in 28 day cycles according to the following schedule: a) a first dose of 0.3 or 1 mg on day 1 of cycle 1, b) a second dose on day 8 of cycle 1, and c) a third dose on day 15 of cycle 1, and e) one or more subsequent doses starting on day 1 of cycle 2 and every two weeks thereafter, wherein the second dose, third dose, and subsequent doses are the same and are 0.3 mg-30 mg or 3 mg-100 mg, respectively, which are higher than the first dose, and the anti-PD-1 antibody is administered every four weeks at a dose of 480 mg.

[0013] E3: The method according to E1 or E2, wherein the DLL3-positive cancer is small cell lung cancer (SCLC).

[0014] E4: The method according to any one of E1 to E3, wherein the DLL3-positive cancer is recurrent / refractory (RR) SCLC or extensive disease (ED) SCLC.

[0015] E5: The method of any one of E1 to E4, wherein the anti-DLL3 agent is a bispecific T cell-inducing antigen-binding polypeptide comprising two binding domains: a first domain that binds to human DLL3, and a second domain that binds to human CD3.

[0016] E6: The method of E4, wherein the DLL3-binding domain binds to an epitope of human DLL3 contained within the amino acid sequence of SEQ ID NO:29.

[0017] E7: The method described in E5 or E6, wherein the DLL3-binding domain comprises: (a) a heavy chain variable region (VH), comprising: (i) a VH complementarity determining region 1 (CDR-H1) comprising the amino acid sequence of SEQ ID NO: 1; (ii) a CDR-H2 comprising the amino acid sequence of SEQ ID NO: 2; and (iii) a CDR-H3 comprising the amino acid sequence of SEQ ID NO: 3; and (b) a light chain variable region (VL), comprising: (i) a VL complementarity determining region 1 (CDR-L1) comprising the amino acid sequence of SEQ ID NO: 4; (ii) a CDR-L2 comprising the amino acid sequence of SEQ ID NO: 5; and (iii) a CDR-L3 comprising the amino acid sequence of SEQ ID NO: 6.

[0018] E8: The method described in any one of E5 to E7, wherein the DLL3-binding domain comprises (1) a VH having the amino acid sequence of SEQ ID NO: 7 and a VL having the amino acid sequence of SEQ ID NO: 8, or (2) a VH having the amino acid sequence of SEQ ID NO: 11 and a VL having the amino acid sequence of SEQ ID NO: 12.

[0019] E9: The method according to any one of E5 to E8, wherein the VH and VL of the DLL3-binding domain are linked by a linker to form a single chain Fv (scFv).

[0020] E10: The method according to E9, wherein the linker comprises a sequence selected from any one of SEQ ID NOs: 42 to 50.

[0021] E11: The method of E9 or E10, wherein the linker comprises (Gly4Ser)x, where x is an integer equal to or greater than 1 (e.g., 1, 2, 3, or 4).

[0022] E12: The method according to any one of E5 to E11, wherein the DLL3-binding domain comprises the amino acid sequence of SEQ ID NO:9 or SEQ ID NO:13.

[0023] E13: The method described in any one of E5 to E12, wherein the CD3 binding domain comprises: (a) a VH comprising CDR-H1 comprising the amino acid sequence of SEQ ID NO: 18, CDR-H2 comprising the amino acid sequence of SEQ ID NO: 19, and CDR-H3 comprising the amino acid sequence of SEQ ID NO: 20; and a VL comprising CDR-L1 comprising the amino acid sequence of SEQ ID NO: 15, CDR-L2 comprising the amino acid sequence of SEQ ID NO: 16, and CDR-L3 comprising the amino acid sequence of SEQ ID NO: 17.

[0024] E14: The method according to any one of E5 to E13, wherein the CD3-binding domain comprises a VH comprising the amino acid sequence of SEQ ID NO:21 and a VL comprising the amino acid sequence of SEQ ID NO:22.

[0025] E15: The method described in E13 or E14, wherein the VH and VL of the CD3 binding domain are linked by a linker to form a single chain Fv (scFv).

[0026] E16: The method according to E15, wherein the linker comprises a sequence selected from any one of SEQ ID NOs: 42 to 50.

[0027] E17: The method of E15 or E16, wherein the linker comprises (Gly4Ser)x, where x is an integer equal to or greater than 1 (e.g., 1, 2, 3, or 4).

[0028] E18: The method according to any one of E13 to E17, wherein the CD3-binding domain comprises the amino acid sequence of SEQ ID NO:23.

[0029] E19: The method according to any one of E5 to E18, wherein the DLL3-binding domain and the CD3-binding domain are linked by a linker.

[0030] E20: The method according to E19, wherein the linker is a peptide linker comprising a sequence selected from any one of SEQ ID NOs: 42 to 50.

[0031] E21: The method of E19 or E20, wherein the linker is a peptide linker comprising (Gly4Ser)x, where x is an integer equal to or greater than 1 (e.g., 1, 2, 3, or 4).

[0032] E22: The method according to any one of E5 to E21, wherein the anti-DLL3 agent is a bispecific T cell-inducing antigen-binding polypeptide comprising a DLL3-binding domain and a CD3-binding domain. The DLL3-binding domain comprises: (a) a heavy chain variable region (VH), comprising: (i) a VH complementarity determining region 1 (CDR-H1) comprising the amino acid sequence of SEQ ID NO: 1; (ii) a CDR-H2 comprising the amino acid sequence of SEQ ID NO: 2; and (iii) a CDR-H3 comprising the amino acid sequence of SEQ ID NO: 3; and (b) a light chain variable region (VL), comprising: (i) a VL complementarity determining region 1 (CDR-L1) comprising the amino acid sequence of SEQ ID NO: 4; (ii) a CDR-L2 comprising the amino acid sequence of SEQ ID NO: 5; and (iii) a CDR-L3 comprising the amino acid sequence of SEQ ID NO: 6. The CD3-binding domain comprises: (a) a VH comprising (i) a CDR-H1 comprising the amino acid sequence of SEQ ID NO: 18, (ii) a CDR-H2 comprising the amino acid sequence of SEQ ID NO: 19, and (iii) a CDR-H3 comprising the amino acid sequence of SEQ ID NO: 20; and (b) a VL comprising (i) a CDR-L1 comprising the amino acid sequence of SEQ ID NO: 15, (ii) a CDR-L2 comprising the amino acid sequence of SEQ ID NO: 16, and (iii) a CDR-L3 comprising the amino acid sequence of SEQ ID NO: 17.

[0033] E23: The method described in any one of E5 to E22, wherein the DLL3 binding domain comprises a VH comprising the amino acid sequence of SEQ ID NO: 7 and a VL comprising the amino acid sequence of SEQ ID NO: 8, and the CD3 binding domain comprises a VH comprising the amino acid sequence of SEQ ID NO: 21 and a VL comprising the amino acid sequence of SEQ ID NO: 22.

[0034] E24: The method described in any one of E5 to E22, wherein the DLL3-binding domain comprises a VH comprising the amino acid sequence of SEQ ID NO: 11 and a VL comprising the amino acid sequence of SEQ ID NO: 12, and the CD3-binding domain comprises a VH comprising the amino acid sequence of SEQ ID NO: 21 and a VL comprising the amino acid sequence of SEQ ID NO: 22.

[0035] E25: The method according to any one of E5 to E23, wherein the DLL3-binding domain comprises the amino acid sequence of SEQ ID NO:9, and the CD3-binding domain comprises the amino acid sequence of SEQ ID NO:23.

[0036] E26: The method according to any one of E5 to E21 or E24, wherein the DLL3 binding domain comprises the amino acid sequence of SEQ ID NO: 13 and the CD3 binding domain comprises the amino acid sequence of SEQ ID NO: 23.

[0037] E27: The method of E25, wherein the anti-DLL3 agent comprises the amino acid sequence of SEQ ID NO:10.

[0038] E28: The method of E27, wherein the anti-DLL3 agent comprises the amino acid sequence of SEQ ID NO:14.

[0039] E29: The method of any one of E5 to E28, wherein the anti-DLL3 agent further comprises a third domain that extends or enhances the serum half-life of the anti-DLL3 agent.

[0040] E30: The method according to E29, wherein the third domain comprises an amino acid sequence selected from any one of SEQ ID NOs: 51 to 58.

[0041] E31: The method according to any one of E5 to E22, E24, E26, and E28 to E30, wherein the anti-DLL3 agent comprises the amino acid sequence of SEQ ID NO: 27 or 59.

[0042] E32: The method of any one of E5 to E31, wherein the anti-PD-1 antibody comprises: (a) a VH comprising (i) a CDR-H1 comprising the amino acid sequence of SEQ ID NO: 32, (ii) a CDR-H2 comprising the amino acid sequence of SEQ ID NO: 33, and (iii) a CDR-H3 comprising the amino acid sequence of SEQ ID NO: 34; and (b) a VL comprising (i) a CDR-L1 comprising the amino acid sequence of SEQ ID NO: 35, (ii) a CDR-L2 comprising the amino acid sequence of SEQ ID NO: 36, and (iii) a CDR-L3 comprising the amino acid sequence of SEQ ID NO: 37.

[0043] E33: The method according to any one of E5 to E32, wherein the anti-PD-1 antibody comprises a VH comprising the amino acid sequence of SEQ ID NO: 38 and a VL comprising the amino acid sequence of SEQ ID NO: 39.

[0044] E34: The method described in any one of E5 to E33, wherein the anti-PD-1 antibody comprises a heavy chain (HC) comprising the amino acid sequence of SEQ ID NO: 40, and a light chain (LC) comprising the amino acid sequence of SEQ ID NO: 41.

[0045] E35: The method of any one of E1 or E3 to E34, wherein the anti-DLL3 agent is administered once every two weeks at a dose of about 0.3 mg to about 30 mg, about 1 mg to about 30 mg, about 3 mg to about 30 mg, or about 10 mg to about 30 mg.

[0046] E36: The method of E35, wherein the anti-DLL3 agent is administered once every two weeks at a dose of about 0.3 mg, 1 mg, 3 mg, 10 mg, 25 mg, or 30 mg.

[0047] E37: The method of any one of E1 or E3 to E34, wherein the anti-DLL3 agent is administered once every two weeks at a dose of about 3 mg to about 100 mg, about 10 mg to about 100 mg, or about 30 mg to about 100 mg.

[0048] E38: The method of E37, wherein the anti-DLL3 agent is administered once every two weeks at a dose of about 3 mg, 10 mg, 25 mg, 30 mg, 50 mg, 75 mg, or 100 mg.

[0049] E39: The method of any one of E2 to E34, wherein the second, third, and subsequent doses of the anti-DLL3 agent are from about 0.3 mg to about 30 mg, from about 1 mg to about 30 mg, from about 3 mg to about 30 mg, or from about 10 mg to about 30 mg, respectively.

[0050] E40: The method of E39, wherein the second, third, and subsequent doses of the anti-DLL3 agent are each a dose of about 0.3 mg, 1 mg, 3 mg, 10 mg, 25 mg, or 30 mg.

[0051] E41: The method of any one of E2 to E34, wherein the second, third, and subsequent doses of the anti-DLL3 agent are from about 3 mg to about 100 mg, from about 10 mg to about 100 mg, or from about 30 mg to about 100 mg, respectively.

[0052] E42: The method of E41, wherein the second, third, and subsequent doses of the anti-DLL3 agent are each a dose of about 3 mg, 10 mg, 25 mg, 30 mg, 50 mg, 75 mg, or 100 mg.

[0053] E43: The method of any one of E1 or E3 to E38, wherein an anti-DLL3 agent is administered on days 1 and 15 of a 28-day cycle, and an anti-PD-1 antibody is administered on days 1, 8, or 15 of a 28-day cycle.

[0054] E44: The method of E43, wherein the anti-PD-1 antibody is administered on day 1, day 8, or day 15 of the first cycle of a 28-day cycle, then starting on day 1 or day 15 of a second or subsequent cycles.

[0055] E45: The method described in any one of E2 to E34 or E39 to E42, in which the anti-PD-1 antibody is administered on day 1, day 8, or day 15 of the first cycle of a 28-day cycle, and then on day 1 or day 15 of a second or subsequent cycles.

[0056] E46: The method of E44 or E45, wherein a) if the anti-PD-1 antibody is administered on day 1 or day 8 of the first cycle, then the antibody is administered starting on day 1 of a second or subsequent cycle, or b) if the anti-PD-1 antibody is administered on day 15 of the first cycle, then the antibody is administered on day 15 of a second or subsequent cycle.

[0057] E47: The method of any one of E1-E46, wherein the method further comprises administering to the subject one or more additional therapeutic agents.

[0058] E48: The method of E47, wherein the one or more additional therapeutic agents is a corticosteroid (e.g., dexamethasone), saline, or tocilizumab.

[0059] E49: The method of E47 or E48, wherein the one or more additional therapeutic agents are administered to the subject during the first cycle of administration of the anti-DLL3 agent.

[0060] E50: The method of any one of E1 to E50, wherein the anti-DLL3 agent is prepared by the process of culturing a host cell comprising a nucleic acid encoding an anti-DLL3 agent of any one of E5 to E31 under conditions allowing expression of the anti-DLL3 agent, and then recovering the expressed anti-DLL3 agent from the cell culture, and the anti-PD-1 antibody is prepared by the process of culturing a host cell comprising a nucleic acid encoding an anti-PD-1 antibody of any one of E32 to E34 under conditions allowing expression of the antibody, and then recovering the expressed anti-PD-1 antibody from the cell culture.

[0061] E51: The method according to any one of E1 to E50, wherein the subject is a human.

[0062] E52: An anti-DLL3 agent and an anti-PD-1 antibody for use in the method according to any one of embodiments E1 to E51.

[0063] E53: An anti-DLL3 agent and an anti-PD-1 antibody for use in treating a DLL3-positive cancer (e.g., SCLC), wherein the anti-DLL3 agent and the anti-PD-1 antibody are administered as described in any one of embodiments E1 to E51.

[0064] E54: Use of an anti-DLL3 agent and an anti-PD-1 antibody for the manufacture of a medicament for the treatment of SCLC, wherein the medicament is prepared for administration as described in any one of embodiments E1 to E51.

[0065] E55: Use of an anti-DLL3 agent and an anti-PD-1 antibody in the preparation of a medicament for the treatment of a DLL3-positive cancer, wherein the anti-DLL3 agent and the anti-PD-1 antibody are administered as described in any one of embodiments E1 to E51. [Brief description of the drawings]

[0066] [Figure 1] 1 shows dose levels of AMG757 and AMG404 in the clinical study exemplified in Example 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0067] AMG757 is a half-life extended BiTE® (bispecific T cell engager) molecule developed for the treatment of SCLC. The activity of AMG757 involves the activation of target cells (DLL3 + The pharmacological effect of AMG757 is to bind to both DLL3 and T cells simultaneously. + Cytotoxic CD8 already primed to kill cells + or CD4 + AMG757 was evaluated in a first-in-human study in subjects with SCLC (Study 20160323) and found to have antitumor activity starting at a dose level of 0.3 mg once every 2 weeks (Q2W) with an acceptable safety profile at doses up to 100 mg Q2W.

[0068] AMG404 is a fully human antibody that binds with high affinity to human PD-1 and blocks the ability of this receptor to interact with its ligands, programmed cell death-ligand 1 (PD-L1) and programmed cell death-ligand 2 (PD-L2). AMG404 has been evaluated in a Phase 1 study (Study 20180143) in subjects with solid tumors and was found to be effective against solid tumors.

[0069] Recently, many clinical trials have been initiated to combine PD1 / PDL1 inhibitors with other anticancer drugs to treat small cell lung cancer. See, for example, NCT04702880 and NCT04256421 (SKYSCRAPER-02). However, the recent announcement of the failure of the SKYSCRAPER-02 trial highlighted the uncertainty of combining PD1 / PDL1 inhibitors with other anticancer drugs in the treatment of this difficult-to-treat cancer. There remains a high unmet need and ongoing challenges when targeting this type of tumor.

[0070] The combination of AMG757 and anti-PD-1 antibody increases T cell-mediated redirected lysis of DLL3-expressing tumor cells compared to AMG757 alone (Amgen Study Report R20190104).Upregulation of PD1 / PDL1 in the tumor microenvironment is thought to be a mechanism of resistance to BiTE therapy that may be mitigated by treatment with anti-PD1 therapy.

[0071] As disclosed and exemplified herein, agents targeting DLL3 (e.g., AMG757) and PD-1 (e.g., pembrolizumab or AMG404) have been used in Phase 1 clinical trials for the treatment of SCLC.

[0072] 1.Definition Some of the exemplary bispecific anti-DLL3 agents disclosed herein (such as BiTE® molecules) are bispecific T cell-inducing antigen-binding polypeptides. These polypeptides are recombinant proteins that contain two binding domains, each domain derived from an antigen-binding fragment of a full-length antibody. Such antigen-binding fragments retain the ability to specifically bind to an antigen (preferably with substantially the same binding affinity). Examples of antigen-binding fragments include: (i) a Fab fragment, which is a monovalent fragment consisting of the VL, VH, CL, and CH1 domains; (ii) a F(ab')2 fragment, which is a bivalent fragment containing two Fab fragments linked by a disulfide bridge at the hinge region; (iii) an Fd fragment consisting of the VH and CH1 domains; (iv) an Fv fragment consisting of the VL and VH domains of a single arm of an antibody; and (v) a dAb fragment consisting of the VH domain (Ward et al., 1989 Nature 341:544-546). Furthermore, although the two domains of the Fv fragment, VL and VH, are encoded by separate genes, they can be joined using recombinant methods by a synthetic linker that allows them to be produced as a single protein chain in which the VL and VH regions pair to form a monovalent molecule, known as a single-chain Fv (scFv); see, e.g., Bird et al. Science 242:423-426 (1988) and Huston et al., 1988, Proc. Natl. Acad. Sci. USA 85:5879-5883.

[0073] "Variable domain" refers to either the variable region of an antibody light chain (VL) or the variable region of an antibody heavy chain (VH), either alone or in combination. As known in the art, the variable regions of the heavy and light chains each consist of four framework regions (FR) linked by three complementarity determining regions (CDRs), which contribute to the formation of the antigen-binding site of an antibody.

[0074] The "complementarity determining regions" (CDRs) of exemplary agents targeting DLL3 and PD-1 are set forth in the sequence listing. CDRs can be defined according to Kabat, Chothia, both Kabat and Chothia accumulation, AbM, contact, North, and / or conformational definitions, or any method of determining CDRs well known in the art. See, for example, Kabat et al., 1991, Sequences of Proteins of Immunological Interest, 5th ed. (hypervariable regions); Chothia et al., 1989, Nature 342:877-883 (structural loop structures). The AbM definition of CDRs is a compromise between Kabat and Chothia, and uses Oxford Molecular's AbM antibody modeling software (Accelrys®). The identity of the amino acid residues of a particular antibody that make up a CDR can be determined using methods well known in the art.

[0075] The term "treatment" includes preventative and / or therapeutic treatment. Treatment is considered preventative when administered prior to clinical signs of a condition. Therapeutic treatment includes, for example, amelioration or reduction of disease severity or shortening of disease duration. Additionally, the term "treat" and related terms do not necessarily mean 100% or complete treatment. Rather, there are various degrees of treatment that are recognized by those skilled in the art as having potential benefits or therapeutic effects. In this regard, the methods of treating cancer of the present disclosure can provide any amount or level of treatment. Additionally, the treatment provided by the methods of the present disclosure can include treatment of one or more pathologies or symptoms or signs of the cancer being treated. The treatment provided by the methods of the present disclosure can also include slowing the progression of the cancer. For example, the methods can treat cancer by enhancing T cell activity or immune response against the cancer, reducing tumor or cancer growth, reducing metastasis of tumor cells, and increasing cell death of tumor or cancer cells, etc. In exemplary embodiments, the method treats to delay the onset or recurrence of cancer by 1 day, 2 days, 4 days, 6 days, 8 days, 10 days, 15 days, 30 days, 2 months, 4 months, 6 months, 1 year, 2 years, 4 years, or more. In exemplary embodiments, the method treats to extend the subject's survival. In various embodiments, the treatment provided by the method of the present disclosure provides a therapeutic response according to the Response Evaluation Criteria in Solid Tumors (RECIST) or other similar criteria. RECIST is a set of criteria for evaluating the progression, stabilization, or response of tumors and / or cancer cells, jointly created by the National Cancer Institute of the United States, the National Cancer Institute of Canada Clinical Trials Group, and the European Organisation for Research and Treatment of Cancer. According to RECIST, a particular tumor is measured at the beginning of evaluation (e.g., a clinical trial) to provide a baseline for comparison after treatment with a drug.Tumor response assessments and assessment criteria are published in Eisenhauer et.al., Eur J Cancer 45:228-247 (2009) and Litiere et.al., Journal of Clinical Oncology 37(13):1102-1110 (2019) DOI:10.1200 / JCO.18.01100. In various instances, the treatment provided by the methods of the present disclosure provides a therapeutic response according to a modified RECIST tumor response assessment, as follows:

[0076] [Table 1A]

[0077] Thus, provided herein are methods of delaying progression of a DLL3-positive cancer in a subject, enhancing T cell activity or immune response to a DLL3-positive cancer in a subject, reducing growth of a DLL3-positive tumor or cancer in a subject, reducing metastasis of DLL3-positive tumor cells in a subject, increasing cell death of a DLL3-positive tumor or cancer cells in a subject, delaying onset or recurrence of a DLL3-positive cancer in a subject, and / or prolonging survival of a subject. Also provided are methods of treating a DLL3-positive cancer to produce a complete response (CR), partial response (PR), or stable disease (SD) in a subject according to modified RECIST 1.1. In various aspects, the method comprises administering to a subject an anti-DLL3 agent and an anti-PD-1 antibody according to the present disclosure. For example, in various aspects, the methods include administering an anti-DLL3 agent comprising the amino acid sequences of SEQ ID NOs: 13 and 23, and an anti-PD-1 antibody comprising the amino acid sequences of SEQ ID NOs: 38 and 39, where the anti-DLL3 agent is administered once every two weeks at a dose of 0.3 mg to 30 mg, or 3 mg to 100 mg, and the anti-PD-1 antibody is administered once every four weeks at a dose of 480 mg. In various instances, the anti-DLL3 agent is administered in 28 day cycles according to the following schedule: a) a first dose of 0.3 mg or 1 mg on day 1 of cycle 1, b) a second dose on day 8 of cycle 1, c) a third dose on day 15 of cycle 1, and d) one or more subsequent doses starting on day 1 of cycle 2 and every two weeks thereafter, where the second, third, and subsequent doses are the same and are 0.3 mg to 30 mg or 3 mg to 100 mg, respectively, higher than the first dose, and the anti-PD-1 antibody is administered every four weeks at a dose of 480 mg. In various aspects, the methods include administering an anti-DLL3 agent comprising the amino acid sequences of SEQ ID NOs: 13 and 23, and an anti-PD-1 antibody approved by a regulatory agency (e.g., the FDA or EMA), where the anti-DLL3 agent is administered once every two weeks at a dose of 0.3 mg to 30 mg, or 3 mg to 100 mg, and the anti-PD-1 antibody is administered at a dose approved by the regulatory agency.

[0078] "About" or "approximately," when used in connection with a measurable numerical variable, refers to the stated value of the variable and all values ​​of the variable that are within the experimental error of the stated value (e.g., within a 95% confidence interval of the mean) or ±10% of the stated value, whichever is greater. Numerical ranges include the numbers defining the range.

[0079] "First stage dose", when used in connection with administration of an anti-DLL3 agent for the treatment of cancer (e.g., SCLC), refers to the initial dose of an anti-DLL3 agent in a staged dose schedule or regimen. Typically, the first stage dose corresponds to a dose at or below which a first dose effect (e.g., cytokine release syndrome (CRS)) is observed. As known in the art, the first stage dose can be determined by modeling and simulation of safety and pharmacokinetic data. For example, the first stage dose can be the maximum tolerated dose (MTD) of the anti-DLL3 agent at which no CRS is observed or CRS of less than a certain grade (e.g., grade 2) is observed.

[0080] "Target dose," when used in connection with administration of an anti-DLL3 agent for the treatment of cancer (e.g., SCLC), refers to the dose at which the target effect of the anti-DLL3 agent is achieved (e.g., remission or reduction in the severity of SCLC, or shortening the duration of SCLC).

[0081] "Step-up dose," when used in connection with administration of an anti-DLL3 agent for the treatment of cancer (e.g., SCLC), refers to a dose in an escalating dose schedule or regimen that is higher than the previous dose at which the anti-DLL3 agent is administered. A step-up dose includes one or more doses that increase from a first step-up dose until a target dose is reached.

[0082] 2. Drugs that target DLL3 DLL3 is a non-canonical Notch ligand that is mainly expressed during embryogenesis and functions during somitogenesis. DLL3 accumulates in the Golgi apparatus in normal tissues (Geffers et al, J Cell Biol.178:465-476(2007)). DLL3 was identified as a tumor-associated antigen and a potential target for T cell-based therapy by analyzing the differential expression of this target in 28 SCLC tumors and a large panel of normal tissues (Study 123658).

[0083] The human DLL3 protein contains eight extracellular domains: signal peptide, N-terminus, DSL, EGF1, EGF2, EGF3, EGF4, EGF5, and EGF6. The amino acid sequences of human DLL3, EGF3 domain, EGF4 domain, and combined EGF3 domain and EGF4 domain are shown in the sequence listing as SEQ ID NOs: 28, 29, 30, and 31, respectively.

[0084] An exemplary agent targeting DLL3 is a bispecific T cell-inducing antigen-binding polypeptide that binds DLL3 and CD3, such as a BiTE® molecule. A BiTE® molecule is a recombinant protein formed from two flexibly linked binding domains, each of which is derived from an antibody. One binding domain of the BiTE® molecule is specific for a tumor-associated surface antigen (e.g., DLL3), and another binding domain is specific for CD3, a subunit of the T cell receptor complex on T cells. These designs make the BiTE® molecule uniquely suitable for transiently linking T cells to target cells and simultaneously potently activating the inherent cytolytic ability of T cells against target cells. See, for example, WO 99 / 54440, WO 2005 / 040220, and WO 2008 / 119567.

[0085] Thus, in some embodiments, the described DLL3 targeting agents comprise two binding domains: a first domain that binds to DLL3 (preferably human DLL3) and a second domain that binds to CD3 (preferably human CD3). Preferably, the first domain binds to an epitope of DLL3 contained in the amino acid sequence of SEQ ID NO: 31. More preferably, the first domain binds to an epitope of DLL3 contained in the amino acid sequence of SEQ ID NO: 29.

[0086] In a specific embodiment, the DLL3 binding domain comprises (a) a heavy chain variable region (VH), comprising: (i) a VH complementarity determining region 1 (CDR-H1) comprising the amino acid sequence of SEQ ID NO: 1; (ii) a CDR-H2 comprising the amino acid sequence of SEQ ID NO: 2; and (iii) a CDR-H3 comprising the amino acid sequence of SEQ ID NO: 3; and (b) a light chain variable region (VL), comprising: (i) a VL complementarity determining region 1 (CDR-L1) comprising the amino acid sequence of SEQ ID NO: 4; (ii) a CDR-L2 comprising the amino acid sequence of SEQ ID NO: 5; and (iii) a CDR-L3 comprising the amino acid sequence of SEQ ID NO: 6.

[0087] In certain embodiments, the DLL3-binding domain comprises a VH comprising the amino acid sequence of SEQ ID NO: 7 and a VL comprising the amino acid sequence of SEQ ID NO: 8. In certain preferred embodiments, the DLL3-binding domain comprises a VH comprising the amino acid sequence of SEQ ID NO: 11 and a VL comprising the amino acid sequence of SEQ ID NO: 12.

[0088] In some embodiments, the VH and VL are linked by a linker to form a single chain Fv (scFv). In some embodiments, the linker is a peptide linker comprising a sequence selected from any one of SEQ ID NOs: 42 to 50. In some embodiments, the linker is a GS linker (e.g., Gly-Gly-Gly-Gly-Ser (G4S, SEQ ID NO: 43)) or a polymer thereof (i.e., (Gly4Ser)x, where x is an integer of 1 or more (e.g., 2 or 3)) (e.g., SEQ ID NOs: 49, 50).

[0089] In certain embodiments, the DLL3 binding domain comprises the amino acid sequence of SEQ ID NO: 9. In certain preferred embodiments, the DLL3 binding domain comprises the amino acid sequence of SEQ ID NO: 13.

[0090] In a specific embodiment, the CD3 binding domain comprises (a) a VH comprising a CDR-H1 comprising the amino acid sequence of SEQ ID NO: 18, a CDR-H2 comprising the amino acid sequence of SEQ ID NO: 19, and a CDR-H3 comprising the amino acid sequence of SEQ ID NO: 20; and a VL comprising a CDR-L1 comprising the amino acid sequence of SEQ ID NO: 15, a CDR-L2 comprising the amino acid sequence of SEQ ID NO: 16, and a CDR-L3 comprising the amino acid sequence of SEQ ID NO: 17.

[0091] In certain embodiments, the CD3 binding domain comprises a VH comprising the amino acid sequence of SEQ ID NO: 21 and a VL comprising the amino acid sequence of SEQ ID NO: 22. In some embodiments, the VH and VL are linked by a linker to form a single chain Fv (scFv). In some embodiments, the linker is a peptide linker comprising a sequence selected from any one of SEQ ID NOs: 42-50. In some embodiments, the linker is a GS linker (e.g., Gly-Gly-Gly-Gly-Ser (G4S, SEQ ID NO: 43)) or a polymer thereof (i.e., (Gly4Ser)x, where x is an integer of 1 or more (e.g., 2 or 3)).

[0092] In a specific embodiment, the CD3 binding domain comprises the amino acid sequence of SEQ ID NO:23.

[0093] In certain embodiments, the DLL3-binding domain and the CD3-binding domain are linked by a linker. In some embodiments, the linker is a peptide linker comprising a sequence selected from any one of SEQ ID NOs: 42 to 50. In some embodiments, the linker is a GS linker (e.g., Gly-Gly-Gly-Gly-Ser (G4S, SEQ ID NO: 43)) or a polymer thereof (i.e., (Gly4Ser)x, where x is an integer of 1 or greater (e.g., 2 or 3)).

[0094] In certain embodiments, the anti-DLL3 agents disclosed herein comprise two domains: the first domain binds to DLL3 (preferably human DLL3) and comprises (a) a heavy chain variable region (VH) comprising (i) a VH complementarity determining region 1 (CDR-H1) comprising the amino acid sequence of SEQ ID NO: 1; (ii) a CDR-H2 comprising the amino acid sequence of SEQ ID NO: 2; and (iii) a CDR-H3 comprising the amino acid sequence of SEQ ID NO: 3; and (b) a light chain variable region (VL) comprising (i) a VL complementarity determining region 1 (CDR-L1) comprising the amino acid sequence of SEQ ID NO: 4; (ii) a CDR-L2 comprising the amino acid sequence of SEQ ID NO: 5; and (iii) a CDR-L3 comprising the amino acid sequence of SEQ ID NO: 6. The second domain binds to CD3 (preferably human CD3) and comprises (a) a VH comprising (i) a CDR-H1 comprising the amino acid sequence of SEQ ID NO: 18, (ii) a CDR-H2 comprising the amino acid sequence of SEQ ID NO: 19, and (iii) a CDR-H3 comprising the amino acid sequence of SEQ ID NO: 20, and (b) a VL comprising (i) a CDR-L1 comprising the amino acid sequence of SEQ ID NO: 15, (ii) a CDR-L2 comprising the amino acid sequence of SEQ ID NO: 16, and (iii) a CDR-L3 comprising the amino acid sequence of SEQ ID NO: 17.

[0095] In certain embodiments, the anti-DLL3 agents described herein comprise two domains: (a) a first domain that binds to DLL3 (preferably human DLL3) and comprises a VH comprising the amino acid sequence of SEQ ID NO:7 and a VL comprising the amino acid sequence of SEQ ID NO:8, and (b) a second domain that binds to CD3 (preferably human CD3) and comprises a VH comprising the amino acid sequence of SEQ ID NO:21 and a VL comprising the amino acid sequence of SEQ ID NO:22. In certain preferred embodiments, the anti-DLL3 agents described herein comprise two domains: (a) a first domain that binds to DLL3 (preferably human DLL3) and comprises a VH comprising the amino acid sequence of SEQ ID NO:11 and a VL comprising the amino acid sequence of SEQ ID NO:12, and (b) a second domain that binds to CD3 (preferably human CD3) and comprises a VH comprising the amino acid sequence of SEQ ID NO:21 and a VL comprising the amino acid sequence of SEQ ID NO:22.

[0096] In certain embodiments, the anti-DLL3 agents described herein comprise two domains: (a) a first domain that binds to DLL3 (preferably human DLL3) and comprises the amino acid sequence of SEQ ID NO: 9, and (b) a second domain that binds to CD3 (preferably human CD3) and comprises the amino acid sequence of SEQ ID NO: 23. In certain embodiments, the anti-DLL3 agents described herein comprise two domains: (a) a first domain that binds to DLL3 (preferably human DLL3) and comprises the amino acid sequence of SEQ ID NO: 13, and (b) a second domain that binds to CD3 (preferably human CD3) and comprises the amino acid sequence of SEQ ID NO: 23.

[0097] In certain embodiments, the anti-DLL3 agents described herein comprise the amino acid sequence of SEQ ID NO: 10. In certain embodiments, the anti-DLL3 agents described herein comprise the amino acid sequence of SEQ ID NO: 14.

[0098] In certain embodiments, the anti-DLL3 agents described herein further comprise a third domain that extends or enhances the serum half-life of the anti-DLL3 agent. In certain embodiments, the third domain comprises two polypeptides linked by a linker, each peptide comprising the hinge, CH2, and CH3 domains of human IgG. In certain embodiments, the third domain comprises, in order from N- to C-terminus, hinge-CH2-CH3-linker-hinge-CH2-CH3. In some embodiments, the linker is a GS linker (e.g., Gly-Gly-Gly-Gly-Ser (G4S, SEQ ID NO: 43)) or a polymer thereof (i.e., (Gly4Ser)x, where x is an integer equal to or greater than 1, e.g., 6). In certain embodiments, the third domain comprises an amino acid sequence selected from any one of SEQ ID NOs: 51-58.

[0099] In certain embodiments, the DLL3 binding domain and the CD3 binding domain are linked by a first linker to form a peptide, and the peptide is linked to the third domain by a second linker. In certain embodiments, the first peptide linker is a peptide linker comprising a sequence selected from any one of SEQ ID NOs: 42-50, and the second linker comprises a sequence selected from any one of SEQ ID NOs: 42, 43, 45, 46, 47, 49, and 50. In some embodiments, the first linker is a GS linker (e.g., Gly-Gly-Gly-Gly-Ser (G4S, SEQ ID NO: 42)) or a polymer thereof (i.e., (Gly4Ser)x, where x is an integer equal to or greater than 1, e.g., 2 or 3), and the second linker comprises a sequence selected from any one of SEQ ID NOs: 42, 43, 45, 46, 47, 49, and 50.

[0100] In certain embodiments, the anti-DLL3 agents described herein comprise three domains: (a) a first domain that binds to DLL3 (preferably human DLL3) and comprises the amino acid sequence of SEQ ID NO: 9; (b) a second domain that binds to CD3 (preferably human CD3) and comprises the amino acid sequence of SEQ ID NO: 23; and (c) a third domain that comprises an amino acid sequence selected from any one of SEQ ID NOs: 51-58. In certain embodiments, the anti-DLL3 agents described herein comprise three domains: (a) a first domain that binds to DLL3 (preferably human DLL3) and comprises the amino acid sequence of SEQ ID NO: 13; (b) a second domain that binds to CD3 (preferably human CD3) and comprises the amino acid sequence of SEQ ID NO: 23; and (c) a third domain that comprises any one of the amino acid sequences selected from SEQ ID NOs: 51-58. In certain embodiments, the anti-DLL3 agents described herein comprise the amino acid sequence of SEQ ID NO: 27. In certain embodiments, the anti-DLL3 agents described herein comprise the amino acid sequence of SEQ ID NO: 59.

[0101] The anti-DLL3 agents described herein can be produced by recombinant DNA techniques known in the art. For example, the anti-DLL3 agents can be produced by a process in which a host cell (e.g., Chinese Hamster Ovary Cybo) containing a nucleic acid encoding the anti-DLL3 agent described herein is cultured under conditions that allow expression of the anti-DLL3 agent, and then the expressed anti-DLL3 agent is recovered from the cell culture. In various cases, the anti-DLL3 agent is tarlatamab (International Nonproprietary Name (INN) for Pharmaceutical Substances: Proposed INN: List 123, WHO Drug Information 34(2):395-397(2020)), also known as AMG757. Tarlatamab is a monoclonal antibody consisting of immunoglobulin scFv-scFv-scFc, anti-[Homo sapiens DLL3 (delta-like ligand 3)] and anti-[Homo sapiens CD3E (CD3ε, Leu-4)], monoclonal antibody single chain (scFv) 2-scFc, bispecific; IG single chain scFv-scFv-scFc, anti-DLL3 and anti-CD3E (1-982) [scFv-VH-V-κ] anti-DLL3 (1-241) [VH (Homo sapiens IGHV4-59 * 01 G49>C(44)(96.9%)-(IGHD)-IGHJ4 * 01 (100%)) CDR-IMGT[8.7.12](26-33.51-57.96-107)(1-118)-15-mer tris(tetraglycyl-seryl) linker(119-133)-V-κ(Homo sapiens IGKV3-20 * 01(91.7%)-IGKJ2 * 01 Q120>C(234)(90.9%))CDRIMGT[7.3.9](160-166.184-186.223-231)(134-241)]-6-mer seryl-tetraglycyl-seryl linker(242-247)-scFv-VH-V-λ anti-CD3E(248-496)[VH(Mus musculus IGHV10-1 * 02(91.9%)-(IGHD)-IGHJ3 *01 (86.7%) / Homo sapiens IGHV3-73 * 01(87.0%)-(IGHD)-IGHJ5 * 01 (100%)) CDR-IMGT[8.10.16](273-280.298-307.346-361)(248-372)-15-mer-tris(tetraglycyl-seryl) linker(373-387)-V-λ(Homo sapiens IGLV7-43 * 01 (85.1%) - IGLJ3 * 02 (100%)) CDR-IMGT[9.3.9](413-421.439-441.478-486)(388-496)]-4-mer-tetraglycyl linker(497-500)-scFc(h-CH2-CH3)-(h-CH2-CH3)(501-982) [Homo sapiens IGHG1 * 03h-CH2-CH3, nG1m1 (hinge 6-15 (501-510), CH2 R83>C (572), N84.4>G (577), V85>C (582) (511-620), CH3 E12 (636), M14 (638) (621-725), CHS>del) (501-725) - 30-mer hexakis(tetraglycyl-seryl) linker (726-755) - Homo sapiens IGHG1 * 03 h-CH2-CH3, nG1m1 (hinge 6-15(756-765), CH2 R83>C(827), N84.4>G(832), V85>C(837)(766-875), CH3 E12(891), M14(893)(876-980), CHS(981-982))(756-982)]], nonglycosylated, produced in Chinese hamster ovary (CHO) cells; immunomodulatory and antineoplastic agent.

[0102] 3. Drugs that target PD-1 Programmed cell death protein 1 (PD-1), also known as CD279, SLEB2, and hSLE1, is a transmembrane protein expressed on activated T, natural killer (NK) and B lymphocytes, macrophages, dendritic cells (DC), and monocytes. In particular, PD-1 is highly expressed on tumor-specific T cells (Han et al., Am J Cancer Res 10(3):727-742(2020)). PD-1 binds to B7 protein family members, PD-1 ligand 1 (PD-L1; also known as CD279 and B7-H1), and PD-1 ligand 2 (PD-L2, also known as CD273 and B7-DC). PD-L1 is constitutively expressed on T and B cells, macrophages, and dendritic cells, whereas PD-L2 expression is typically restricted to activated DCs and macrophages (Xing et al., Oncoimmunology 7(3):e1356144(2017)(doi:10.1080 / 2162402X.2017.1356144)). PD-1 inhibits both adaptive and innate immune responses. The PD-1 / PD-L1 axis is involved in suppressing T cell immune responses in cancer. Antagonists of this pathway are being clinically validated in many solid tumor indications. The PD-1 inhibitors nivolumab, pembrolizumab, and cemiplimab, and the PD-L1 inhibitors atezolizumab, avelumab, and durvalumab target the PD-1 / PD-L1 pathway and each has been approved by the U.S. Food and Drug Administration (FDA) and / or the European Medicines Agency (EMA) for the treatment of various cancers. Further exemplary agents that target PD-1 include tislelizumab, dostallimab, penprimab, sintilimab, toripalimab, dostallimab, camrelizumab, zimblerimab, and prorugolimab. In certain embodiments, a PD-1 targeted agent that may be used in the treatments disclosed herein is nivolumab, pembrolizumab, cemiplimab, tislelizumab, dostallimab, pemplimab, sintilimab, toripalimab, dostallimab, camrelizumab, zimblerimab, or prorugolimab.In certain embodiments, the PD-1 targeted agent is nivolumab, pembrolizumab, cemiplimab, tislelizumab, or sintilimab. In certain embodiments, the PD-1 targeted agent is nivolumab or pembrolizumab.

[0103] Still further exemplary agents targeting PD-1 include the PD-1 antigen binding proteins (e.g., anti-PD-1 antibodies, antigen-binding antibody fragments thereof, and anti-PD-1 antibody protein products) described in WO 2019 / 140196, the entire contents of which are incorporated herein by reference. In exemplary embodiments, the PD-1 antigen binding protein binds to human PD-1 having the amino acid sequence set forth in National Center for Biotechnology Information (NCBI) Reference SEQ ID NO: NP_005009.2, or SEQ ID NO: 60, or its mature form represented by amino acids 21-288 of SEQ ID NO: 60 (e.g., lacking a signal peptide). In exemplary embodiments, the PD-1 antigen binding protein binds to cynomolgus PD-1 having the amino acid sequence set forth in NCBI Reference SEQ ID NO: NP_001271065.1, or SEQ ID NO: 61, or its mature form. In exemplary cases, the PD-1 antigen binding protein binds to both human PD-1 and cynomolgus PD-1. In an exemplary embodiment, the anti-PD-1 antibody comprises the amino acid sequences of SEQ ID NOs: 32 to 37. In an exemplary embodiment, the anti-PD-1 antibody comprises the six CDR amino acid sequences of SEQ ID NOs: 32 to 37. In an exemplary embodiment, the anti-PD-1 antibody comprises a heavy chain (HC) complementarity determining region (CDR) 1 amino acid sequence of SEQ ID NO: 32, a HC CDR2 amino acid sequence of SEQ ID NO: 33, a HC CDR3 amino acid sequence of SEQ ID NO: 34, a light chain (LC) CDR1 amino acid sequence of SEQ ID NO: 35, a LC CDR2 amino acid sequence of SEQ ID NO: 36, and a LC CDR3 amino acid sequence of SEQ ID NO: 37. In certain embodiments, the anti-PD-1 antibody comprises a PD-1 binding domain comprising: (a) a heavy chain variable region (VH), wherein the VH comprises: (i) a VH complementarity determining region 1 (CDR-H1) comprising the amino acid sequence of SEQ ID NO: 32; (ii) a CDR-H2 comprising the amino acid sequence of SEQ ID NO: 33; and (iii) a CDR-H3 comprising the amino acid sequence of SEQ ID NO: 34; and (b) a light chain variable region (VL), wherein the VL comprises: (i) a VL complementarity determining region 1 (CDR-L1) comprising the amino acid sequence of SEQ ID NO: 35; (ii) a CDR-L2 comprising the amino acid sequence of SEQ ID NO: 36; and (iii) a CDR-L3 comprising the amino acid sequence of SEQ ID NO: 37.In certain embodiments, the PD-1 binding domain comprises a VH comprising the amino acid sequence of SEQ ID NO: 38 and a VL comprising the amino acid sequence of SEQ ID NO: 39. In certain embodiments, the anti-PD-1 antibody comprises a VH comprising the amino acid sequence of SEQ ID NO: 38 and a VL comprising the amino acid sequence of SEQ ID NO: 39. In certain preferred embodiments, the anti-PD-1 antibody comprises a HC comprising the amino acid sequence of SEQ ID NO: 40 and a LC comprising the amino acid sequence of SEQ ID NO: 41. In various instances, the anti-PD-1 antibody is zelvalimab (International Nonproprietary Name (INN) for Pharmaceutical Substances: Proposed INN: List 124, WHO Drug Information 34(4):929-1102(2020)), also referred to as AMG404. Zelvalimb is a monoclonal antibody containing immunoglobulin G1-κ, anti-[Homo sapiens PDCD1 (programmed cell death 1, PD-1, PD1, CD279)], gamma 1 heavy chain (1-450) [VH (Homo sapiens IGHV3-23. * 03(92.8%)-(IGHD)-IGHJ3 * 01(92.3%))CDR-IMGT[8.8.13](26-33.50-58.97-109)(1-120)-Homo sapiens IGHG1 * 03v, G1m3>G1m17, nG1m1 (CH1 R120>K(217)(121-218), hinge 1-15(219-233), CH2 R83>C(295), N84.4>G(300), V85>C(305)(234-343), CH3 E12(359), M14(361)(344-448), CHS(449-450))(121-450)], with disulfide (223-214')-κ light chain (1'-214') [V-κ (Homo sapiens IGKV1-12 * 01(96.8%)-IGKJ4 * 01(100%))CDR-IMGT[6.3.9](27-32.50-52.89-97)(1'-107')-Homo sapiensIGKC *01(100%), Km3 A45.1(153), V101(191)(108'-214')]; dimeric (229-229):232-232''-bisdisulfide, produced in Chinese hamster ovary (CHO) cells, a non-glycosylated immunomodulatory and antineoplastic agent.

[0104] 4. Treatment regimens using agents targeting DLL3 and PD-1 Disclosed herein is a method of treating a DLL3-positive cancer, comprising administering to a subject in need thereof a combination of agents targeting DLL3 and PD-1. Agents targeting DLL3 include anti-DLL3 agents disclosed herein, and agents targeting PD-1 include anti-PD-1 antibodies disclosed herein. In one embodiment, disclosed herein is a method of treating a DLL3-positive cancer, comprising administering to a subject in need thereof a combination of an anti-DLL3 agent and an anti-PD-1 antibody, wherein the anti-DLL3 agent is administered at a dose of about 0.3 mg to about 30 mg, or about 3 mg to about 100 mg, once every two weeks. In various embodiments, the anti-PD-1 antibody is nivolumab, pembrolizumab, zelvalimab, or tislelizumab. In certain embodiments, the DLL3-positive cancer is small cell lung cancer (SCLC). In certain embodiments, the SCLC is relapsed / refractory SCLC (RR SCLC) or extensive stage SCLC (ED SCLC). In certain embodiments, the subject is a human with SCLC (e.g., RR SCLC or ED SCLC). In certain embodiments, the subject's SCLC has relapsed after at least one prior platinum-based therapy.

[0105] In certain embodiments, the anti-DLL3 agent is administered once every two weeks at a dose of about 0.3 mg to about 30 mg, about 1 mg to about 30 mg, about 3 mg to about 30 mg, or about 10 mg to about 30 mg. In certain embodiments, the anti-DLL3 agent is administered once every two weeks at a dose of about 0.3 mg, 1 mg, 3 mg, 10 mg, 25 mg, or 30 mg.

[0106] In certain embodiments, the anti-DLL3 agent is administered once every two weeks at a dose of about 3 mg to about 100 mg, about 10 mg to about 100 mg, or about 30 mg to about 100 mg. In certain embodiments, the anti-DLL3 agent is administered once every two weeks at a dose of about 3 mg, 10 mg, 25 mg, 30 mg, 50 mg, 75 mg, or 100 mg.

[0107] The anti-DLL3 agent may be administered by any suitable means, for example, parenterally, intrapulmonary, intranasally, and / or intralesionally. Parenteral administration includes intramuscular, intravenous, intraarterial, intraperitoneal, or subcutaneous administration. In some embodiments, the anti-DLL3 agent is administered by intravenous (IV) infusion (e.g., a short IV infusion (about 60 minutes)) once every two weeks.

[0108] In some embodiments where the anti-DLL3 agent is administered at the above doses, the anti-PD-1 antibody is zelvalimab, and the anti-PD-1 antibody is administered at a dose of 480 mg once every four weeks. In certain embodiments, the anti-DLL3 agent and zelvalimab are administered in a 28-day cycle, and either agent may be administered on day 1 of cycle 1. To reduce the risk of first dose effects of AMG757 (e.g., cytokine release syndrome (CRS)) that may be exacerbated by the combination of the anti-PD-1 antibody on day 1 of cycle 1, the anti-PD-1 antibody may be administered on day 8 or day 15 of cycle 1. Thus, in certain embodiments, the anti-DLL3 agent is administered on days 1 and 15 of a 28-day cycle, and the anti-PD-1 antibody is administered on days 1, 8, or 15 of a 28-day cycle.

[0109] In certain embodiments of such a 28-day cycle dosing regimen, the anti-DLL3 agent is administered on days 1 and 15, and zelvalimab is administered on days 1, 8, or 15 of cycle 1, then starting on days 1 or 15 of cycle 2 or later. In such embodiments, if zelvalimab is administered on day 1 or day 8 of cycle 1, then the antibody is administered starting on day 1 of cycle 2 or later; or, if zelvalimab is administered on day 15 of cycle 1, then the antibody is administered starting on day 15 of cycle 2 or later.

[0110] Other known anti-PD-1 antibodies (e.g., pembrolizumab and nivolumab) can also be used in combination with the anti-DLL3 agent in the methods disclosed herein. When used in combination, the doses and regimens of these other anti-PD-1 antibodies are the same as those approved by regulatory authorities (e.g., FDA). For example, as described in Example 1, the anti-DLL3 agent was used in combination with pembrolizumab in a clinical study in SCLC patients, and pembrolizumab was administered at a dose of 200 mg every three weeks. Thus, in some embodiments in which the anti-DLL3 agent is administered at the above doses, the anti-PD-1 antibody is pembrolizumab, and the anti-PD-1 antibody is administered at a dose of 200 mg once every three weeks. In some embodiments in which the anti-DLL3 agent is administered at the above doses, the anti-PD-1 antibody is nivolumab, and the anti-PD-1 antibody is administered at a dose of 240 mg once every two weeks. In some embodiments where the anti-DLL3 agent is administered in the above doses, the anti-PD-1 antibody is tislelizumab, and the anti-PD-1 antibody is administered at a dose of 200 mg once every three weeks.

[0111] In embodiments where the anti-DLL3 agent is administered every two weeks and the anti-PD-1 antibody is administered every three weeks, to reduce the risk of first dose effects (e.g., CRS), the anti-PD-1 antibody can be initiated on day 15 of cycle 1. Thus, in certain embodiments, the first cycle of administration of the anti-DLL3 agent and anti-PD-1 antibody is a 28 day cycle, with the anti-DLL3 agent administered on days 1 and 15 and the anti-PD-1 antibody administered on day 15, after which the anti-DLL3 agent is administered every two weeks and the anti-PD-1 antibody is administered every three weeks.

[0112] The anti-PD-1 antibody can be administered by any suitable means, for example, parenterally, hi some embodiments, the anti-PD-1 antibody is administered by intravenous IV infusion once every two weeks, once every three weeks, or once every four weeks, depending on the antibody.

[0113] As used herein, "combination therapy" or "in combination with" refers to the administration of one therapeutic modality (e.g., an anti-DLL3 agent) in addition to another therapeutic modality (e.g., an anti-PD-1 antibody). As such, "combination therapy" or "in combination with" refers to the administration of one therapeutic modality before, during, or after the administration of the other therapeutic modality to an individual (e.g., a human with SCLC). However, combination therapy does not include a situation in which 28 days or more elapse between the end of administration of one therapeutic modality and the start of another therapeutic modality.

[0114] 4.1 Step administration Due to its mechanism of action, subjects may be at increased risk of first dose effects (e.g., CRS) after the first infusion of AMG757, which may be exacerbated by the combination of anti-PD-1 antibodies. To mitigate the risk, a step-dosing regimen can be implemented. For example, if a subject experiences a first dose effect (e.g., CRS), an appropriate first dose that does not exceed the dose at which a CRS event is observed can be determined and implemented. One or more step doses can also be determined and implemented until a target dose is reached. These doses and dosing schedules can be guided by new pharmacokinetic and safety data and information available for AMG757.

[0115] An exemplary phased dosing schedule for an anti-DLL3 agent (eg, AMG757) in a 28 day cycle is shown in the table below (first cycle only), followed by dosing of the anti-DLL3 agent once every two weeks.

[0116] [Table 1]

[0117] Thus, disclosed herein is a method of treating DLL3 positive cancer, comprising administering to a subject in need thereof an anti-DLL3 agent and an anti-PD-1 antibody, wherein the anti-DLL3 agent is administered according to a one-step dosing schedule as outlined above in Table 1. The anti-PD-1 antibody can be nivolumab, pembrolizumab, zelvalimab, or tislelizumab. For example, the anti-PD-1 antibody is zelvalimab, and in various embodiments where a step-dosing regimen is implemented for AMG757, is administered once every four weeks at a dose of 480 mg.

[0118] In certain embodiments, the anti-DLL3 agent is administered according to a one-stage dosing schedule. In such embodiments, disclosed herein are methods of treating DLL3-positive cancer, comprising administering to a subject in need thereof an anti-DLL3 agent and an anti-PD-1 antibody, wherein the anti-DLL3 agent is administered in 28-day cycles according to the following schedule: a) a first dose of about 0.3 mg or 1 mg on day 1 of cycle 1, b) a second dose on day 8 of cycle 1, c) a third dose on day 15 of cycle 1, and d) one or more subsequent doses starting on day 1 of cycle 2 and every two weeks thereafter, wherein the second dose, the third dose, and the subsequent doses are the same and are each about 0.3 mg to about 30 mg or about 3 mg to about 100 mg, higher than the first dose. In some embodiments, the anti-PD-1 antibody is zelvalimab and is administered every four weeks at a dose of about 480 mg. In some embodiments, the anti-PD-1 antibody is nivolumab, pembrolizumab, or tislelizumab and is administered at a dose / regimen approved by a regulatory agency.

[0119] In certain embodiments where the anti-DLL3 agent is administered according to a one-stage dosing schedule, the first dose of the anti-DLL3 agent is about 0.3 mg or 1 mg, and the second, third, and subsequent doses are about 0.3 mg to about 30 mg, about 1 mg to about 30 mg, about 3 mg to about 30 mg, or about 10 mg to about 30 mg, respectively. In certain embodiments, the first dose of the anti-DLL3 agent is about 0.3 mg, and the second, third, and subsequent doses are about 1 mg, 3 mg, 10 mg, 25 mg, or 30 mg, respectively. In certain embodiments, the first dose of the anti-DLL3 agent is about 1 mg, and the second, third, and subsequent doses are about 3 mg, 10 mg, 25 mg, or 30 mg, respectively.

[0120] In certain embodiments where the anti-DLL3 agent is administered according to a one-stage dosing schedule, the first dose of the anti-DLL3 agent is about 0.3 mg or 1 mg, and the second, third, and subsequent doses are each about 3 mg to about 100 mg, about 10 mg to about 100 mg, or about 30 mg to about 100 mg. In certain embodiments, the first dose is about 0.3 mg, and the second, third, and subsequent doses are each about 1 mg, 10 mg, 25 mg, 30 mg, 50 mg, 75 mg, or 100 mg. In certain embodiments, the first dose is about 1 mg, and the second, third, and subsequent doses are each about 10 mg, 25 mg, 30 mg, 50 mg, 75 mg, or 100 mg.

[0121] In a particular embodiment, the anti-PD-1 antibody is zelvalimab and is administered on day 1, day 8, or day 15 of cycle 1, then starting on day 1 or day 15 of cycle 2 or later. If the anti-PD-1 antibody is administered on day 1 or day 8 of cycle 1, then the antibody is administered on day 1 of cycle 2 or later. Alternatively, if zelvalimab is administered on day 15 of cycle 1, then the antibody is administered on day 15 of cycle 2 or later.

[0122] In certain embodiments, the anti-DLL3 agent is administered according to a two-phase dosing schedule. Accordingly, disclosed herein is a method of treating a DLL3-positive cancer, comprising administering to a subject in need thereof an anti-DLL3 agent and an anti-PD-1 antibody, wherein the anti-DLL3 agent is administered according to Schedule I or Schedule II, as described below. Schedule I: a) a first dose of 0.3 mg or 1 mg on day 1 of cycle 1 (step dose), b) a second dose on day 4 of cycle 1 (step dose), c) a third dose on day 8 of cycle 1 (step dose, which corresponds to the target dose), d) a fourth dose on day 15 of cycle 1 (target dose), and e) one or more subsequent doses (target doses) starting on day 1 of cycle 2 and every two weeks thereafter, where the second dose is higher than the first dose, and the third, fourth, and subsequent doses are the same and are about 0.3 mg to 30 mg or 3 mg to 100 mg, respectively, and higher than the second dose; or Schedule II: a) a first dose of 0.3 mg or 1 mg on day 1 of cycle 1 (step dose), b) a second dose on day 8 of cycle 1 (step dose), c) a third dose on day 15 of cycle 1 (step dose, corresponding to the target dose), and d) one or more subsequent doses (target doses) starting on day 1 of cycle 2 and every two weeks thereafter, where the second dose is higher than the first dose, and the third dose and subsequent doses are the same and are about 0.3 mg to 30 mg or 3 mg to 100 mg, respectively, and higher than the second dose; The regimen involves administering 50 mg of PD-1 antibody every 4 weeks at a dose of 480 mg in a 28-day cycle according to the FDA guidelines.

[0123] In certain embodiments, if pharmacokinetics and safety data are deemed satisfactory, the step dose on day 4 of cycle 1 of schedule I described above can be equal to or greater than the target dose.However, the step dose or target dose does not exceed the amount of 100 mg.This administration schedule is considered to be beneficial in that it may lead to improved PD activity (e.g., it helps to quickly achieve desired serum AMG757 level).

[0124] In certain embodiments, disclosed herein are methods of treating DLL3 positive cancer, comprising administering an anti-DLL3 agent to a subject in need thereof, wherein the anti-DLL3 agent is administered according to a three-phase dosing schedule. In such embodiments, disclosed herein are methods of treating DLL3 positive cancer, comprising administering an anti-DLL3 agent and an anti-PD-1 antibody to a subject in need thereof, wherein the anti-DLL3 agent is administered according to the following schedule: a) a first dose of about 0.3 mg or 1 mg on day 1 of cycle 1 (phase one dose), b) a second dose on day 4 of cycle 1 (phase dose), c) a third dose on day 8 of cycle 1 (phase dose), d) a fourth dose on day 15 of cycle 1 (phase dose, which corresponds to the target dose), and e) Starting on day 1 of the second cycle, one or more subsequent doses (target doses) are administered every two weeks in a 28-day cycle, where the second dose is higher than the first dose, the third dose is higher than the second dose, and the fourth dose and subsequent doses are the same, each about 0.3 mg to about 30 mg or about 3 mg to about 100 mg, and higher than the third dose, and the anti-PD-1 antibody is nivolumab, pembrolizumab, zelvalimab, or tislelizumab, administered at the doses and schedules described above. In certain embodiments, the anti-PD-1 antibody is zelvalimab, administered once every four weeks at a dose of 480 mg. In other embodiments, the anti-PD-1 antibody is pembrolizumab, administered once every three weeks at a dose of 200 mg.

[0125] In certain embodiments, if the pharmacokinetic and safety data are deemed satisfactory, the step dose on day 8 of the first cycle of the three-step dosing regimen described above may represent the target dose. Such a dosing schedule is believed to be beneficial in that it helps to rapidly achieve the desired serum AMG757 level.

[0126] The anti-DLL3 agent and the anti-PD-1 antibody can be administered by any suitable means, for example, parenterally, intrapulmonary, intranasally, and / or intralesionally. Parenteral administration includes intramuscular, intravenous, intraarterial, intraperitoneal, or subcutaneous administration. In some embodiments, the anti-DLL3 agent is administered by IV infusion and the anti-PD-1 antibody is administered by IV infusion.

[0127] In certain embodiments, the DLL3 positive cancer is small cell lung cancer (SCLC). In certain embodiments, the SCLC is relapsed / refractory SCLC (RR SCLC) or extensive stage SCLC (ED SCLC). In certain embodiments, the subject is a human with SCLC (e.g., RR SCLC or ED SCLC), and in certain embodiments, the subject's SCLC has relapsed after at least one prior platinum-based chemotherapy.

[0128] 4.2 Additional Therapeutic Drugs In some embodiments, the methods disclosed herein further include the use of one or more additional therapeutic agents to prevent, reduce, or mitigate the risk of adverse effects associated with the administration of anti-DLL3 agents and anti-PD-1 antibodies. The main adverse effect associated with the use of anti-DLL3 agents is CRS. The one or more additional therapeutic agents useful for preventing, reducing, or mitigate the risk of CRS include corticosteroids (e.g., dexamethasone), fluids (e.g., saline), etanercept (e.g., Enbrel), and anti-IL6 antibodies (e.g., tocilizumab or siltuximab). Dexamethasone may be administered by IV administration prior to all first cycle doses of AMG757, including all escalating doses, saline (e.g., 1 liter) may be administered IV following all MG757 doses in the first cycle, and anti-IL6 antibodies (tocilizumab or siltuximab) may be administered as needed (e.g., subjects who do not respond to IV fluids). Exemplary doses of dexamethasone include 8 mg / administration (maximum 24 mg / day). Exemplary doses of tocilizumab include 8 mg / kg (not to exceed 800 mg). Symptoms of CRS include fever, nausea, fatigue, headache, myalgia, malaise, and therapeutic agents useful for treating these symptoms (e.g., paracetamol / acetaminophen for fever) may also be used.

[0129] Adverse events following anti-PD-1 antibody therapy may include immune-mediated rejection reactions, which may occur as soon as the first dose or within several months after the last dose of therapy. Immune-mediated rejection reactions associated with anti-PD-1 antibodies include pneumonia, colitis / diarrhea, immune-mediated hepatitis, adrenal insufficiency, nephritis and renal dysfunction, encephalopathy, skin rash, hypothyroidism, hyperthyroidism, and diabetes mellitus. The one or more additional therapeutic agents useful for preventing, reducing, or mitigating the risk of such immune-related rejection reactions (e.g., one or more of pneumonia, colitis / diarrhea, immune-mediated hepatitis, adrenal insufficiency, nephritis and renal insufficiency, encephalopathy, skin rashes, hypothyroidism, hyperthyroidism, and diabetes mellitus) include corticosteroids (e.g., prednisone, hydrocortisone, and dexamethasone), insulin therapy (for diabetes mellitus), thyroid hormone replacement (for hypothyroidism), and beta-blockers (e.g., atenolol, propranolol for hyperthyroidism).

[0130] Thus, in certain embodiments, the methods disclosed herein further comprise administering one or more additional therapeutic agents selected from corticosteroids (e.g., prednisone, hydrocortisone, and dexamethasone), fluids (saline), anti-IL6 antibodies (e.g., tocilizumab or siltuximab), insulin therapy, thyroid hormone replacement, and beta-blockers (e.g., atenolol, propranolol). In certain embodiments, the methods further comprise one or more additional therapeutic agents selected from corticosteroids (e.g., dexamethasone), fluids (saline), and tocilizumab or siltuximab. In certain embodiments, one or more of corticosteroids, fluids, and anti-IL6 antibodies (e.g., tocilizumab or siltuximab) are administered in the first cycle in which AMG757 is administered.

[0131] In one particular embodiment of any of the methods of administering one or more additional therapeutic agents, the subject is a human.

[0132] 5.Product Disclosed herein is an article of manufacture that includes: (a) a container containing an anti-DLL3 agent; and (b) a package insert that includes instructions for treating a DLL3 positive cancer (or for treating SCLC) in a subject by administering the anti-DLL3 agent (e.g., AMG 757) in combination with an anti-PD-1 antibody (e.g., pembrolizumab or AMG 404), the instructions providing for administering the anti-DLL3 agent at a dose of about 0.3 mg to about 30 mg or about 3 mg to about 100 mg (or any of the dose ranges disclosed herein) to the subject once every two weeks (e.g., on days 1 and 15 of a 28 day cycle). In certain embodiments, the article of manufacture further includes a container that includes an anti-PD-1 antibody.

[0133] The instructions may also specify that the anti-DLL3 agent is to be administered in 28 day cycles according to the following schedule: a) a first dose of 0.3 mg or 1 mg on day 1 of cycle 1, b) a second dose on day 8 of cycle 1, c) a third dose on day 15 of cycle 1, and d) one or more subsequent doses starting on day 1 of cycle 2 and every two weeks thereafter, wherein the second, third, and subsequent doses are the same and are each 0.3 mg to 30 mg or 3 mg to 100 mg (or any of the dose ranges disclosed herein) and higher than the first dose.

[0134] The instructions may also specify that the anti-PD-1 antibody is administered on day 1, day 8, or day 15 of a 28 day cycle, e.g., administering the anti-PD-1 antibody on day 1, day 8, or day 15 of cycle 1, then starting on day 1 or day 15 of cycle 2 or later. The instructions may also specify that if the anti-PD-1 antibody is administered on day 1 or day 8 of cycle 1, then it is administered starting on day 1 of cycle 2 or later; or, if the anti-PD-1 antibody is administered on day 15 of cycle 1, then it is administered starting on day 15 of cycle 2 or later.

[0135] The instructions may further provide for administering one or more therapeutic agents to the subject in addition to the anti-DLL3 agent and the anti-PD-1 antibody. The one or more therapeutic agents may be selected from corticosteroids (e.g., dexamethasone, prednisone, hydrocortisone, etc.), saline, etanercept, and an anti-IL6 antibody (tocilizumab or siltuximab). In certain embodiments, the instructions provide for administering one or more of dexamethasone, saline, and an anti-IL6 antibody (tocilizumab or siltuximab) during the first cycle of administering the anti-DLL3 agent. In certain embodiments, the instructions provide for further administering dexamethasone (e.g., by IV administration prior to the first cycle dose of the anti-DLL3 agent) during the first cycle of administering the anti-DLL3 agent.

[0136] 6. Target In various instances of the methods disclosed herein, the subject is a human subject. In exemplary cases, the human subject has small cell lung cancer (SCLC), optionally with histologically or cytologically confirmed SCLC. In various aspects, the human is male or female and / or is 18 years of age or older with SCLC. In exemplary aspects, the human subject has undergone platinum-based chemotherapy. In exemplary aspects, the human subject has RR SCLC that has progressed or relapsed after at least one platinum-based chemotherapy. In exemplary cases, the human subject has an Eastern Cooperative Oncology Group (ECOG) performance status of 0-1 (Oken et al., Am J Clin Oncol 5:649-655 (1982)). In various aspects, the human subject has one or more brain metastases that are being treated. In various aspects, the platinum-based chemotherapy includes carboplatin or cisplatin, platinum-etoposide or platinum-irinotecan.

[0137] 7. Cancer In various embodiments, the cancer treated by the method of the present disclosure is a DLL3 positive cancer. In various cases, the cancer treated by the method of the present disclosure is a small cell lung cancer (SCLC). In an exemplary embodiment, the SCLC is histologically or cytologically confirmed SCLC. Optionally, the SCLC is measurable by modified response criteria in solid tumors (RECIST) 1.1, where measurable lesions include (a) non-nodal lesions with clear boundaries that can be precisely and continuously measured in one dimension of the axial plane (longest diameter ≧10 mm measured by magnetic resonance imaging / computed tomography (MRI / CT) with scan slice thickness ≦5 mm) and / or (b) nodal lesions with longest diameter ≧15 mm perpendicular to the long axis (short axis) on MRI / CT, ​​and / or exclude simple cysts, pleural / pericardial effusions, and ascites. EXAMPLES

[0138] Example 1 Safety, Tolerability, PK, and Antitumor Activity of AMG757 in Combination with Pembrolizumab in Subjects with SCLC A clinical trial was conducted using AMG757 in combination with pembrolizumab in subjects with SCLC. The primary objectives of the study are to evaluate the safety and tolerability of AMG757 when administered in combination with pembrolizumab and to determine the maximum tolerated dose (MTD) or recommended phase 2 dose (RP2D) of AMG757 in combination with pembrolizumab. Secondary objectives of the study are to characterize the PK of AMG757 when administered in combination with pembrolizumab and to evaluate the preliminary antitumor activity of AMG757 in combination with pembrolizumab.

[0139] The main eligibility criteria are summarized in the table below.

[0140] [Table 1B]

[0141] The starting dose of AMG757 was 0.1 mg IV every 2 weeks. The dose of AMG757 was titrated to the following: 0.1 mg, 0.3 mg, 1 mg, 3 mg, 10 mg, 30 mg, and 100 mg IV every 2 weeks. The dose of pembrolizumab was fixed at 200 mg IV every 3 weeks. The first dose of pembrolizumab was administered on day 15 of cycle 1.

[0142] As of April 2022, eight subjects were treated with the combination of AMG757 and pembrolizumab. Subjects received pembrolizumab, 200 mg IV, every 3 weeks, and AMG757, either 0.1 mg (N=5) or 0.3 mg (N=3), IV, every 2 weeks. Of the eight subjects, three subjects achieved stable disease as their best overall response, with an objective response rate of 0% and a disease control rate of 37.5%. One study subject continued treatment 22 months after the first dose of AMG757 in June 2020, with a stable disease response.

[0143] All subjects experienced at least one treatment-emergent adverse event, with fatigue being the most common adverse event in 5 / 8 (62.5%). One subject (0.3 mg AMG757) experienced a treatment-related eligible adverse event (grade ≥ 3 CRS). No subjects had a treatment-emergent adverse event leading to treatment discontinuation. No fatal adverse events were recorded in any of the dose combinations explored in any subject.

[0144] Example 3 Study to Evaluate the Safety and Efficacy of AMG757 in Combination with AMG404 in Subjects with SCLC Objectives and Endpoints The objectives and endpoints of the study (Study 20200439) are summarized in the table below.

[0145] [Table 1C]

[0146] Study design Study 20200439 is a Phase 1b, multicenter, open-label study evaluating the safety, tolerability, PK, PD, and efficacy of AMG 757 in combination with AMG 404 in subjects with SCLC. The study consists of a dose-finding (Part 1) and a dose-finding (Part 2) phase.

[0147] The dose-finding part of the study will use a modified toxicity probability interval (mTPI-2) design to estimate recommended Phase 2 target doses of AMG 757 in combination with AMG 404. RP2D combinations may be identified based on new safety, efficacy, and pharmacodynamic data prior to reaching the MTD.

[0148] AMG404 will be administered as a short-term IV infusion (30 min) at a dose of 480 mg every 28 days (± 3 days) throughout the study. The starting dose of AMG757 is one dose level below the recommended Phase 2 target dose determined in the ongoing FIH study (Study 20160323). The planned dose levels in Study 20160323 are 0.003 mg, 0.01 mg, 0.03 mg, 0.1 mg, 0.3 mg, 1 mg, 3 mg, 10 mg, 30 mg, and 100 mg. The highest planned target dose of AMG757 will not exceed 100 mg in this combination study.

[0149] To mitigate the risk of CRS and potentially optimize the PD activity of AMG757, a stepped dosing approach will be implemented as part of the initial dosing schedule. Based on the recommended Phase 2 target dose and associated dosing schedule selected in Study 20160323, one of the following stepped dosing schedules will be implemented: one phase, two phases (option 1 or option 2), or three phases. AMG404 will be administered at a dose of 480 mg starting on day 1 of cycle 1. Based on new safety data, the dosing schedule may be adjusted to allow AMG404 to be administered initially on day 8 of cycle 1 or day 15 of cycle 1. Depending on which day of cycle 1 AMG404 is administered, starting cycle 2, AMG404 will be administered every 4 weeks starting on day 1 of cycle 2 or day 15 of cycle 2 (note that if AMG404 is administered initially on day 8 of cycle 1, there is a 21-day interval between dosing on day 8 of cycle 1 and day 1 of cycle 2).

[0150] Part 1 may include one or more of the following planned dose levels of AMG 757 in combination with a fixed dose of AMG 404 (see Figure 1): Dose cohort level 1: AMG757 at one dose level below the recommended Phase 2 target dose was administered IV Q2W (step-dosing) in combination with AMG404 480 mg IV every 4 weeks (Q4W) starting on Day 1 of Cycle 1. Dose cohort level 2: AMG757 at the recommended Phase 2 target dose was administered IV Q2W (step-dosing) in combination with AMG404 480 mg IV Q4W starting on Day 1 of Cycle 1. Dose cohort level-1: AMG757 at one dose level below the recommended Phase 2 target dose was administered IV Q2W (step-dosing) in combination with AMG404 IV at 480 mg Q4W starting on day 8 of cycle 1 (if dose cohort level 1 was poorly tolerated). Dose cohort level -2: AMG 757 at one dose level below the recommended Phase 2 target dose, administered IV Q2W (step-dosing) in combination with AMG 404 IV at 480 mg Q4W starting on day 15 of cycle 1 (if dose cohort level -1 was poorly tolerated). Dose cohort level-3: AMG 757 at a dose level two below the recommended Phase 2 target dose, administered IV Q2W (step-dosing) in combination with AMG 404 480 mg IV Q4W starting on day 15 of cycle 1 (if dose cohort level-2 was poorly tolerated).

[0151] Based on emerging PK, PD, and safety data, alternative dosing schedules, including adjusting the AMG757 dose before adjusting the AMG404 dosing date in cycle 1, or additional tiered dosing strategies for AMG757 may also be considered as part of the DLRM de-escalation recommendation.

[0152] Dose escalation / de-escalation recommendations are guided by the mTPI-2 model (Guo et al., 2017), which has a target toxicity probability of 30%, an equivalent toxicity interval of (25%, 33%), and a probability of overdose of 95%, using beta(1,1) as the prior distribution.

[0153] Phased dosing: Subjects may be at increased risk for cytokine release syndrome upon initial AMG757 treatment. Modifications to the phased dosing approach may be required for optimal recommended Phase 2 doses. Additionally, modifications to the phased dosing approach may be required to optimize PD activity of AMG757 and AMG404.

[0154] The phased dosing schedule is summarized below. The dosing schedule may be adapted to include one or more of the following treatments according to DLRT recommendations based on emerging safety and PD data. · One tiered dosing with: 1st tiered dose on day 1, followed by tiered dose (equal to target dose) on day 8, and target dose on day 15, then Q2W. · Two-phase dosing (option 1) with: 1st phase dose on day 1, followed by a phase dose on day 4, a phase dose (equal to the target dose) on day 8, and a target dose on day 15, then Q2W. · Two-phase dosing (option 2) with: 1st phase dose on day 1, followed by a phase dose on day 8, a phase dose on day 15 (equal to the target dose), and the target dose on C2D1, then Q2W. Three phase dosing with: 1st phase dose on day 1, followed by a phase dose on day 4, a phase dose on day 8, a phase dose on day 15 (equal to the target dose), and a target dose on C2D1, then Q2W.

[0155] If the PK, PD, and safety data are deemed satisfactory, the step-up dose on day 4 of cycle 1 of option 1 described above may be equal to or greater than the target dose, however, the step-up dose or target dose will not exceed an amount of 100 mg.

[0156] Part 2 (Dose Expansion): Upon completion of Part 1 of the study, enrollment into Part 2 will begin to confirm the safety and tolerability of the selected doses and to further evaluate the efficacy of AMG757 in combination with AMG404.

[0157] Table 2 summarizes the eligibility criteria for 20200439.

[0158] [Table 2-1]

[0159] [Table 2-2]

[0160] As of April 2022, five subjects in the study were treated with one phase of AMG757 10 mg Q2W and one phase of AMG404 480 mg Q4W. Two subjects had unconfirmed partial responses, one had completed six cycles of treatment, and the other had completed two cycles of treatment. The remaining subject was in their first cycle of treatment. No subjects experienced treatment-emergent adverse events greater than grade 2. One subject experienced a grade 5 event due to underlying disease, not related to treatment. No subjects experienced treatment-emergent adverse events leading to treatment discontinuation.

[0161] This specification is best understood in light of the teachings of the references cited herein. The embodiments within the specification provide illustrations of embodiments of the invention and should not be construed as limiting the scope of the invention. Those skilled in the art will readily recognize that many other embodiments are encompassed by the invention. All publications, patents, and sequences cited in this disclosure are incorporated by reference in their entirety. To the extent that the material incorporated by reference contradicts or is inconsistent with the present specification, the present specification takes precedence over any such material. The citation of any reference herein is not an admission that such reference is prior art to the present invention.

[0162] Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the invention described herein, which equivalents are intended to be encompassed by the embodiments described above.

Claims

1. 1. A combination for use in treating a subject having small cell lung cancer (SCLC), said combination comprising an anti-DLL3 agent comprising the amino acid sequences of SEQ ID NOs: 13 and 23 and an anti-PD-1 antibody, wherein the anti-DLL3 agent is administered once every two weeks at a dose of 0.3 mg to 30 mg or 3 mg to 100 mg, and wherein the subject's SCLC has relapsed after at least one prior platinum-based chemotherapy.

2. 2. The combination of claim 1, wherein the anti-DLL3 agent is administered once every two weeks in a dose of 1 mg to 30 mg.

3. 2. The combination of claim 1, wherein the anti-DLL3 agent is administered once every two weeks at a dose of 3 mg, 10 mg, 25 mg, or 30 mg.

4. 2. The combination according to claim 1, characterized in that the anti-DLL3 agent is administered once every two weeks in a dose of 10 mg to 100 mg.

5. 2. The combination of claim 1, wherein the anti-DLL3 agent is administered once every two weeks at a dose of 10 mg, 25 mg, 30 mg, 50 mg, 75 mg, or 100 mg.

6. A combination according to any one of claims 1 to 5, characterized in that the anti-DLL3 agent is administered on days 1 and 15 of a 28 day cycle.

7. The combination of claim 6, wherein the anti-PD-1 antibody is nivolumab, pembrolizumab, cemiplimab, tislelizumab, sintilimab, or zelvalimab.

8. The combination of claim 7, wherein the anti-PD-1 antibody is pembrolizumab, and the pembrolizumab is administered at a dose of 200 mg once every three weeks.

9. The combination of claim 7, wherein the anti-PD-1 antibody is nivolumab, and the nivolumab is administered at a dose of 240 mg once every two weeks.

10. The combination of claim 7, wherein the anti-PD-1 antibody is zervalimab, and the zervalimab is administered at a dose of 480 mg once every three weeks.

11. 9. The combination of claim 8, wherein pembrolizumab is administered before the anti-DLL3 agent if both are administered on the same day.

12. A combination described in any one of claims 1 to 5, characterized in that one or more additional therapeutic agents are further administered to the subject.

13. 13. The combination of claim 12, wherein the one or more additional therapeutic agents are a corticosteroid, saline, or tocilizumab.

14. The combination of claim 13, wherein the corticosteroid is dexamethasone.

15. 13. The combination of claim 12, wherein the one or more additional therapeutic agents are administered during the first cycle of administration of the anti-DLL3 agent.

16. The combination according to any one of claims 1 to 5, wherein said platinum-based chemotherapy is platinum-etoposide therapy.

17. A combination according to any one of claims 1 to 5, characterized in that the anti-DLL3 agent is administered by IV infusion.

18. The combination according to any one of claims 1 to 5, wherein the subject is a human.

19. A composition for use in treating a subject having small cell lung cancer (SCLC), the composition comprising an anti-DLL3 agent comprising the amino acid sequences of SEQ ID NOs: 13 and 23, the composition being administered in combination with an anti-PD-1 antibody, the anti-DLL3 agent being administered at a dose of 0.3 mg to 30 mg or 3 mg to 100 mg once every two weeks, and wherein the subject's SCLC has relapsed following at least one prior platinum-based chemotherapy.

20. The composition of claim 19, wherein the anti-DLL3 agent is administered at a dose of 1 mg to 30 mg once every two weeks.

21. The composition of claim 19, wherein the anti-DLL3 agent is administered once every two weeks at a dose of 3 mg, 10 mg, 25 mg, or 30 mg.

22. The composition of claim 19, wherein the anti-DLL3 agent is administered at a dose of 10 mg to 100 mg once every two weeks.

23. The composition of claim 19, wherein the anti-DLL3 agent is administered once every two weeks at a dose of 10 mg, 25 mg, 30 mg, 50 mg, 75 mg, or 100 mg.

24. The composition of claim 19, wherein the anti-DLL3 agent is administered on days 1 and 15 of a 28-day cycle.

25. The composition of claim 21, wherein the anti-DLL3 agent is administered on days 1 and 15 of a 28-day cycle.

26. The composition of claim 23, wherein the anti-DLL3 agent is administered on days 1 and 15 of a 28-day cycle.

27. The composition of any one of claims 24 to 26, wherein the anti-PD-1 antibody is nivolumab, pembrolizumab, cemiplimab, tislelizumab, sintilimab, or zelvalimab.

28. The composition of claim 27, wherein the anti-PD-1 antibody is pembrolizumab, and the pembrolizumab is administered at a dose of 200 mg once every three weeks.

29. The composition of claim 27, wherein the anti-PD-1 antibody is nivolumab, and the nivolumab is administered at a dose of 240 mg once every two weeks.

30. The composition of claim 27, wherein the anti-PD-1 antibody is zelvalimab, and the zelvalimab is administered at a dose of 480 mg once every three weeks.

31. The composition of claim 28, wherein pembrolizumab is administered before the anti-DLL3 agent if both are administered on the same day.

32. A composition described in any one of claims 19 to 26, characterized in that one or more additional therapeutic agents are further administered to the subject.

33. The composition described in claim 32, wherein the one or more additional therapeutic agents are a corticosteroid, saline, or tocilizumab.

34. The composition described in claim 33, wherein the corticosteroid is dexamethasone.

35. The composition of claim 32, wherein the one or more additional therapeutic agents are administered during the first cycle of administration of the anti-DLL3 agent.

36. The composition described in any one of claims 19 to 26, wherein the platinum-based chemotherapy is platinum-etoposide therapy.

37. The composition of any one of claims 19 to 26, wherein the anti-DLL3 agent is administered by IV infusion.

38. The composition described in any one of claims 19 to 26, wherein the subject is a human.

39. A composition for use in treating a subject having small cell lung cancer (SCLC), the composition comprising an anti-PD-1 antibody, the composition being administered in combination with an anti-DLL3 agent comprising the amino acid sequences of SEQ ID NOs: 13 and 23, the anti-DLL3 agent being administered once every two weeks at a dose of 0.3 mg to 30 mg or 3 mg to 100 mg, and wherein the subject's SCLC has previously relapsed after at least one platinum-based chemotherapy.

40. The composition of claim 39, wherein the anti-DLL3 agent is administered at a dose of 1 mg to 30 mg once every two weeks.

41. The composition of claim 39, wherein the anti-DLL3 agent is administered once every two weeks at a dose of 3 mg, 10 mg, 25 mg, or 30 mg.

42. The composition of claim 39, wherein the anti-DLL3 agent is administered at a dose of 10 mg to 100 mg once every two weeks.

43. The composition of claim 39, wherein the anti-DLL3 agent is administered once every two weeks at a dose of 10 mg, 25 mg, 30 mg, 50 mg, 75 mg, or 100 mg.

44. The composition of claim 39, wherein the anti-DLL3 agent is administered on days 1 and 15 of a 28-day cycle.

45. The composition of claim 41, wherein the anti-DLL3 agent is administered on days 1 and 15 of a 28-day cycle.

46. ​​The composition of claim 43, wherein the anti-DLL3 agent is administered on days 1 and 15 of a 28-day cycle.

47. The composition of any one of claims 44 to 46, wherein the anti-PD-1 antibody is nivolumab, pembrolizumab, cemiplimab, tislelizumab, sintilimab, or zelvalimab.

48. The composition of claim 47, wherein the anti-PD-1 antibody is pembrolizumab, and the pembrolizumab is administered at a dose of 200 mg once every three weeks.

49. The composition of claim 47, wherein the anti-PD-1 antibody is nivolumab, and the nivolumab is administered at a dose of 240 mg once every two weeks.

50. The composition of claim 47, wherein the anti-PD-1 antibody is zelvalimab, and the zelvalimab is administered at a dose of 480 mg once every three weeks.

51. The composition of claim 48, wherein pembrolizumab is administered before the anti-DLL3 agent, if both are administered on the same day.

52. A composition described in any one of claims 39 to 46, characterized in that one or more additional therapeutic agents are further administered to the subject.

53. The composition described in claim 52, wherein the one or more additional therapeutic agents are a corticosteroid, saline, or tocilizumab.

54. The composition of claim 53, wherein the corticosteroid is dexamethasone.

55. The composition of claim 52, wherein the one or more additional therapeutic agents are administered during the first cycle of administration of the anti-DLL3 agent.

56. The composition of any one of claims 39 to 46, wherein the platinum-based chemotherapy is platinum-etoposide therapy.

57. The composition of any one of claims 39 to 46, wherein the anti-DLL3 agent is administered by IV infusion.

58. The composition described in any one of claims 39 to 46, wherein the subject is a human.

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