Methods of treating cancer by administering Anti-PD-l1 / Anti-4-1BB bispecific antibodies

Abstract

Provided herein is a method of treating a cancer in a subject in need thereof, comprising administering a therapeutically effective amount of an anti-PD-L1 / anti-4-1BB bispecific antibody or an antigen binding fragment thereof to the subject. Provided herein is a pharmaceutical composition for the method provided herein, comprising therapeutically effective amount of the anti-PD-L1 / anti-4-1BB bispecific antibody or antigen binding fragment thereof. Also provided herein is a use of the anti-PD-L1 / anti-4-1BB bispecific antibody in preparing a medicament for treating cancer in a subject in need thereof according to the method provided herein. Further provided herein is an article of manufacture, comprising: (1) an anti-PD-L1 / anti-4-1BB bispecific antibody or a pharmaceutical composition comprising thereof, and (2) a package insert which suggests administration of the anti-PD-L1 / anti-4-1BB bispecific antibody according to the method provided herein.

Description

METHODS OF TREATING CANCER BY ADMINISTERING ANTI-PD-L1 / ANTI-4-1BB BISPECIFIC ANTIBODIES

[0001] Immunotherapy has broadened the scope of treatment by significantly improving prognosis of cancer treatment. Also, immunotherapy using monoclonal antibodies has shown excellent drug tolerability and improved long-term survival rates across a wide range of tumor types.

[0002] A representative example of immunotherapy is treatment using PD-L1 inhibitors. PD-L1 is a ligand for PD-1, and when PD-1 is bound to PD-L1, the PD-1 checkpoint pathway is activated, resulting in inhibition of T cell proliferation, cytokine production, and cytolytic function. PD-L1 inhibitors are known to exhibit anti-tumor effects by blocking this pathway such that the number of effector T cells increases and the cytolytic activity is improved. However, cancer treatment remains a major challenge in patients who are refractory to such immunotherapy or have a relapse.

[0003] 4-1BB is a member of TNF-receptor superfamily (TNFRSF) and is a costimulatory molecule which is expressed following the activation of immune cells, both innate and adaptive immune cells. 4-1BB plays important role in modulate the activity of various immune cells. 4-1BB agonists enhance immune cell proliferation, survival, secretion of cytokines and cytolytic activity CD8 T cells. Many other studies showed that activation of 4-1BB enhances immune response to eliminate tumors in mice. These previous studies suggest that 4-1BB is a promising target molecule in cancer immunology. However, there have been cases of toxicity resulting from systemic immune cell activation when anti-4-1BB antibodies were administered to humans, and therefore there is an unmet need for improvement in such cases.

[0004] Bispecific antibodies are protein complexes with binding sites targeting different epitopes or antigens. Unresolved challenges in the development of bispecific antibodies are to overcome drug resistance of conventional single target biologics, and simultaneously to manage unacceptable toxicity by reaching thresholds through multimolecular pathways and immunogenicity activation.

[0005] There is still an unmet need for new treatments for patients who are difficult to treat with existing cancer treatments, and in particular, therapeutic methods that can overcome refractoriness and / or relapse to existing cancer treatments are needed. There is also an unmet need for therapeutic methods that can achieve therapeutic benefits while managing unacceptable toxicity that may occur in patients.

[0006] Summary

[0007] Provided herein is a method of treating a cancer in a subject in need thereof, comprising administering a therapeutically effective amount of an anti-PD-L1 / anti-4-1BB bispecific antibody or an antigen binding fragment thereof to the subject.

[0008] In an aspect, the method of the present disclosure comprises administering a therapeutically effective amount of the anti-PD-L1 / anti-4-1BB bispecific antibody comprising a PD-L1 targeting moiety that specifically binds PD-L1 and a 4-1BB targeting moiety that specifically binds 4-1BB, wherein the PD-L1 targeting moiety comprises a VH CDR1 consisting of an amino acid sequence of SEQ ID NO: 1, a VH CDR2 consisting of an amino acid sequence of SEQ ID NO: 2, a VH CDR3 consisting of an amino acid sequence of SEQ ID NO: 3, a VL CDR1 consisting of an amino acid sequence of SEQ ID NO: 4, a VL CDR2 consisting of an amino acid sequence of SEQ ID NO: 5, a VL CDR3 consisting of an amino acid sequence of SEQ ID NO: 6, and wherein the 4-1BB targeting moiety comprises a VH CDR1 consisting of an amino acid sequence of SEQ ID NO: 7, a VH CDR2 consisting of an amino acid sequence of SEQ ID NO: 8, a VH CDR3 consisting of an amino acid sequence of SEQ ID NO: 9, a VL CDR1 consisting of an amino acid sequence of SEQ ID NO: 10, a VL CDR2 consisting of an amino acid sequence of SEQ ID NO: 11, a VL CDR3 consisting of an amino acid sequence of SEQ ID NO: 12.

[0009] Provided herein is a pharmaceutical composition for the method provided herein, comprising therapeutically effective amount of the anti-PD-L1 / anti-4-1BB bispecific antibody or antigen binding fragment thereof.

[0010] Also provided herein is a use of the anti-PD-L1 / anti-4-1BB bispecific antibody in preparing a medicament for treating cancer in a subject in need thereof according to the method provided herein.

[0011] Further provided herein is an article of manufacture, comprising: (1) an anti-PD-L1 / anti-4-1BB bispecific antibody or a pharmaceutical composition comprising thereof, and (2) a package insert which suggests administration of the anti-PD-L1 / anti-4-1BB bispecific antibody according to the method provided herein.

[0012] Definition

[0013] Terms herein are used for the same meaning as those generally used in the art, unless otherwise defined below.

[0014] As used herein, an "antibody" refers to a polypeptide or a polypeptide complex that specifically recognizes and binds to an antigen. The antibody can be a whole antibody or any antigen binding fragment thereof. Thus the term "antibody" includes any protein or peptide containing molecule that comprises at least a portion of an immunoglobulin molecule having biological activity of binding to the antigen. Examples of such include, but are not limited to a complementarity determining region (CDR) of a heavy or light chain or a ligand binding portion thereof, a heavy chain or light chain variable region, a heavy chain or light chain constant region, a framework (FR) region, or any portion thereof, or at least one portion of a binding protein. The term "antibody" herein is used in the broadest sense and encompasses various antibody structures, including, but not limited to, monoclonal antibodies, polyclonal antibodies, monospecific and multi-specific antibodies (e.g., bispecific antibodies), and antibody fragments so long as they exhibit the desired antigen-binding affinity.

[0015] The term "bispecific" means that the antibody is able to specifically bind to at least two distinct antigenic determinants; for example, with two binding sites, capable of binding to different antigens or different epitopes on the same antigen.

[0016] The term "anti-PD-L1 / anti-4-1BB bispecific antibody" herein includes antibodies that can effectively recognize and bind to both PD-L1 and 4-1BB. The "anti-PD-L1 / anti-4-1BB bispecific antibody" binds to both PD-L1 and 4-1BB. The "anti-PD-L1 / anti-4-1BB bispecific antibody" includes a PD-L1 targeting moiety capable of recognizing and / or binding to PD-L1, and also includes a 4-1BB targeting moiety capable of recognizing and / or binding to 4-1BB. In an embodiment of the present disclosure, the "anti-PD-L1 / anti-4-1BB bispecific antibody" exhibits antagonistic activity for PD-L1 and agonistic activity for 4-1BB. Examples of the anti-PD-L1 / anti-4-1BB bispecific antibody are disclosed in International laid-open publication No. WO 2020 / 107715 (published on June 4, 2020), the disclosure of which is incorporated by reference herein.

[0017] The term "therapeutically effective amount" herein refers to the amount of the bispecific antibody required to be administered to a cancer patient to achieve a desired therapeutic or preventive result. Also, the therapeutically effective amount refers to the amount of the bispecific antibody without causing unacceptable toxicity associated with treatment or therapy in a patient. For example, when administering a pharmaceutical composition including a therapeutically effective amount of the bispecific antibody to a patient, the following therapeutic effects may be expected: the growth of a tumor stops after administration and the tumor size remains unchanged or does not increase; the tumor size is reduced compared to the tumor size before administration; or the tumor size is reduced after administration and the tumor completely disappears after a certain period of time.

[0018] The term "treatment" herein refers to clinical intervention in an attempt to alter the natural course of a disease in a subject being treated, and may be performed for prevention or even during a clinical pathology process for diagnosing cancer. Desirable effects of treatment may include, although not limited thereto, prevention of occurrence or recurrence of a disease, alleviation of symptoms, reduction in any direct or indirect pathological consequences of the disease, prevention of metastasis, a decrease in rate of disease progression, amelioration or alleviation of the disease condition, and remission or improved prognosis. In some embodiments, a treatment method of the present disclosure may be used to delay the development or progression of a disorder or disease.

[0019] The term "delay the progression" of a disorder or disease herein refers to withholding, hindering, holding off, blocking, stabilizing, and / or postponing a disorder or disease (e.g., cancer or tumor). The time for which the progression of a disorder or disease is delayed by the treatment method of the present disclosure may vary depending on a patient being treated. As will be apparent to those skilled in the art, sufficient or significant delay may, in effect, include prevention in the sense that a disease does not develop in a subject.

[0020] The term "administer" herein encompasses various forms of the verb, including "administers", "administering", and "administered", and refers to a process of delivering given doses of an active ingredient (e.g., the anti-PD-L1 / anti-4-1BB bispecific antibody) or composition (e.g., a pharmaceutical composition including the anti-PD-L1 / anti-4-1BB bispecific antibody) to a subject (e.g., a patient with cancer). Active ingredients and / or compositions used in the method described herein may be administered intravenously (e.g., by intravenous injection).

[0021] The term "flat dose" of a therapeutic agent (e.g., the bispecific antibody) herein refers to a dose administered to a patient without considering a body weight or body surface area of a patient. In this regard, a flat or constant dose is not expressed as a dose in mg / kg or mg / m2, but is rather expressed as an absolute amount (e.g., mg) of a therapeutic agent. The term "weight-based dose" of a therapeutic agent (e.g., the bispecific antibody) refers to a dose administered to a patient in proportion to a body weight of a patient. The weight-based dose is expressed as a dose in mg / kg.

[0022] The term "administration cycle" or "cycle" herein refers to a course of administration of the anti-PD-L1 / anti-4-1BB bispecific antibody repeatedly on a regular schedule, optionally with a rest period (no treatment) in between. In an embodiment of the present disclosure, one administration cycle is defined as 28 days, wherein a pharmaceutical composition including the anti-PD-L1 / anti-4-1BB bispecific antibody may be administered by intravenous injection on Day 1 and Day 15 of the 28-day cycle, optionally followed by a rest period. Treatment according to the present disclosure may include two or more administration cycles.

[0023] The term "tumor" herein refers to a mass of abnormal tissue formed in a case where cells grow and differentiate more than they are supposed to grow and differentiate or a case where cells do not die when they are supposed to die. The tumor may be benign or malignant, and a malignant tumor is called a "cancer". The term "solid tumor" refers to a cancer that has grown abnormally from cells of a solid organ that may be present in a solid organ within a patient. In an embodiment, the solid tumor may be a progressive locally advanced tumor (unresectable), or a metastatic solid tumor. For example, the solid cancer may include, but is not limited to, nasopharyngeal cancer, head and neck cancer, head and neck squamous cell carcinoma, esophageal cancer, ovarian cancer (including primary peritoneal carcinoma and / or fallopian tube adenocarcinoma), melanoma, gastric cancer, breast cancer (such as triple-negative breast cancer), colon cancer, colorectal cancer, prostate cancer, bone cancer, liver cancer, hepatocellular carcinoma, lung cancer, small cell lung cancer, non-small cell lung cancer, urothelial bladder cancer, pancreatic cancer, thyroid cancer, renal cancer, renal cell carcinoma, cholangiocarcinoma, bile duct cancer, Merkel cell carcinoma, brain cancer, cervical cancer, endometrial cancer, bladder cancer, squamous cell carcinoma (such as cutaneous squamous cell carcinoma), and adrenal gland cancer. Preferably, the solid cancer may be nasopharyngeal cancer, head and neck cancer, head and neck squamous cell carcinoma, esophageal cancer, ovarian cancer, gastric cancer, melanoma, liver cancer, hepatocellular carcinoma, or lung cancer.

[0024] The term "complete response (CR)" herein is used to describe disappearance of all signs of cancer in response to treatment, e.g., disappearance of all target lesions. The CR does not always mean that the cancer has been cured. The term "partial response (PR)" herein is used to describe a decrease in the tumor size or the extent of a cancer in the body in response to treatment, and for example, describes at least 30 % decrease in the sum of the long axis of all target lesions, taking as reference the sum of the long axis in the baseline examination. The term "stable disease (SD)" is used to describe a state in which the extent or severity of a cancer is neither decreased nor increased, and for example, describes a state in which the sum of the long axis of all target lesions does not meet both the criteria for PR and the criteria for progressive disease. The term "progressive disease (PD)" refers to either at least a 20 % increase in the sum of the long axis of all target lesions, taking as reference the smallest sum recorded after the start of treatment, or to the appearance of at least one new lesion. The term "progression-free survival (PFS)" is defined as a period of time from first treatment with the anti-PD-L1 / anti-4-1BB bispecific antibody to first occurrence of PD or death from any cause, whichever occurs first. The term "overall survival (OS)" is defined as a period from first treatment with the anti-PD-L1 / anti-4-1BB bispecific antibody to death from any cause.

[0025] The term "overall response rate (ORR)" is defined as a proportion of patients who have a CR and a PR among a group of patients administered the bispecific antibody. The term "clinical benefit rate (CBR)" is defined as a proportion of patients who have a CR, a PR, and a SD among a group of patients administered the bispecific antibody.

[0026] The term "refractory" is used according to the meaning commonly used in the art, and may refer to a condition in which symptoms are not improved, alleviated, relieved, or cured by existing or standard cancer treatments due to extremely low sensitivity to such treatments such as surgery, cytotoxic therapy, chemotherapy, radiation therapy, targeted therapy, immunotherapy, or a combination thereof. For example, not all cancer patients can be cured with existing or standard cancer treatments, and thus some cancer patients may not be able to achieve therapeutic benefit from existing or standard cancer treatments. These cancer patients are referred to as patients refractory to existing or standard cancer treatments.

[0027] The term "relapsed" herein is used according to the meaning commonly used in the art, and may refer to a relapse of cancer at the site of origin in a patient who has been declared cured with existing or standard cancer treatments. For example, a patient who has been treated for cancer with existing or standard cancer treatments may be in remission without any sign or symptom of cancer and remain in remission for a significant period of time, but then cancer may recur in the same site and the patient may need to be treated again. These patients are referred to as patients relapsed to existing or standard treatments.

[0028] The term "existing cancer therapies (or treatments)" or "standard cancer therapies (or treatments)" herein refers to therapies (or treatments) that conventionally known to be useful in treating cancer. Although not specifically limited, these therapies may include surgery, cytotoxic therapy, chemotherapy, radiation therapy, targeted therapy (e.g., therapy using anti-VEGF antibodies such as bevacizumab and ranibizumab), immunotherapy, or a combination thereof.

[0029] The term "chemotherapy" herein is used according to the meaning commonly used in the art, and refers to anti-cancer therapy including administration of chemical compounds that are effective in inhibiting tumor growth. The chemotherapy may include, for example, administering to a subject platinum-based compounds, taxane-based compounds, nucleotide analogs, topoisomerase inhibitors, or a combination thereof, but is not limited thereto. The platinum-based compounds may include carboplatin, nedaplatin, cisplatin, and oxaliplatin, but are not limited thereto. The taxane-based compounds may include paclitaxel and docetaxel, but are not limited thereto. The nucleotide analogs may include 5-fluorouracil, capecitaibine, gemcitabine, fludarabine, cytarabine, mercaptopurine, thioguanine, pentostatin, and hydroxyurea, but are not limited thereto. In addition, the chemotherapy may include a therapy of administering chemical compounds such as topoisomerase inhibitors (e.g., irinotecan, topotecan, camptothecin, doxorubicin, topotecan, etoposide, teniposide, and daunorubicin) and the like, but is not limited thereto.

[0030] As used herein, the term "immunotherapy" is used according to the meaning commonly used in the art, and refers to treating a disease by activating or suppressing the immune system. The immunotherapy may include both activation immunotherapy, which is designed to induce or amplify an immune response, and suppression immunotherapy, which reduces or suppresses an immune response. In cancer treatment, immunotherapy generally refers to a therapy that induces or amplifies and then activates an immune response that has been reduced by cancer. Such immunotherapy may include antibody therapy and cell therapy, but is not limited thereto.

[0031] As used herein, the terms "checkpoint inhibitor" or "immune checkpoint inhibitor" in the present disclosure are used interchangeably, and refer to an agent acting on a cell surface protein considered to be a checkpoint of the immune response, such as a member of the TNF-receptor or B7 superfamily, including an agent that bind to a negative costimulatory molecule. As sued herein, the term "checkpoint inhibitor" may include a therapeutic agent used to modulate the activity of immune system checkpoints. Examples of the checkpoint inhibitor may include proteins binding to ligands respectively for CTLA-4, PD-1, TIM-3, BTLA, TIGIT, VISTA, LAG-3, and / or PD-L1. The term "checkpoint inhibitor" in the context may include an antibody or antigen-binding fragment, a small molecule, or any other binding agents, agonists, activators, inhibitors, and / or blocking agents. For example, the checkpoint inhibitor may include Ipilimumab (CTLA-4 inhibitor; sold under the brand name Yervoy®, Bristol-Myers Squibb Company, Delaware), Nivolumab (PD-1 inhibitor; sold under the brand name Opdivo®, Bristol-Myers Squibb), Pembrolizumab (PD-1 inhibitor; sold under the brand name Keytruda®, Merck Sharp & Dohme; Dohme, New Jersey), and Atezolizumab (PD-L1 inhibitor; sold under the brand name Tecentriq®, Genentech, Inc., Delaware).

[0032] Anti-PD-L1 / anti-4-1BB bispecific antibody

[0033] The present disclosure provides an anti-PD-L1 / anti-4-1BB bispecific antibody that may be useful in the treatment of cancer patients. The anti-PD-L1 / anti-4-1BB bispecific antibody is a bispecific antibody that combine PD-L1 inhibitory activity and 4-1BB agonistic activity to overcome the limitations of existing PD-L1 treatments and 4-1BB-related toxicities. The anti-PD-L1 / anti-4-1BB bispecific antibody of the present disclosure blocks PD-1 / PD-L1 signaling involved in immunosuppression and activates 4-1BB signaling involved in immunostimulation.

[0034] An example of the anti-PD-L1 / anti-4-1BB bispecific antibody that may be used in treatment methods of the present disclosure is ABL503. ABL503 is an anti-PD-L1 / anti-4-1BB bispecific antibody disclosed in International laid-open publication No. WO 2020 / 107715, which is herein incorporated by reference in its entirety for all purposes. ABL503 is characterized by CDRs of antigen targeting moiety as shown below table 1.

[0035] NameSequenceSEQ ID NO.PD-L1 targeting moietyVH CDR1SYDMS1VH CDR2TISDAGGYIYYRDSVKG2VH CDR3ELPWRYALDY3VL CDR1KASQDVTPAVA4VL CDR2STSSRYT5VL CDR3QQHYTTPLT64-1BB targeting moietyVH CDR1SYDMS7VH CDR2WISYSGGSIYYADSVKG8VH CDR3DAQRNSMREFDY9VL CDR1SGSSSNIGNNYVT10VL CDR2ADSHRPS11VL CDR3ATWDYSLSGYV12

[0036] In an embodiment, the anti-PD-L1 / anti-4-1BB bispecific antibody comprises a PD-L1 targeting moiety that specifically binds PD-L1 and a 4-1BB targeting moiety that specifically binds 4-1BB, wherein the PD-L1 targeting moiety comprises a VH CDR1 consisting of an amino acid sequence of SEQ ID NO: 1, a VH CDR2 consisting of an amino acid sequence of SEQ ID NO: 2, a VH CDR3 consisting of an amino acid sequence of SEQ ID NO: 3, a VL CDR1 consisting of an amino acid sequence of SEQ ID NO: 4, a VL CDR2 consisting of an amino acid sequence of SEQ ID NO: 5, a VL CDR3 consisting of an amino acid sequence of SEQ ID NO: 6, and wherein the 4-1BB targeting moiety comprises a VH CDR1 consisting of an amino acid sequence of SEQ ID NO: 7, a VH CDR2 consisting of an amino acid sequence of SEQ ID NO: 8, a VH CDR3 consisting of an amino acid sequence of SEQ ID NO: 9, a VL CDR1 consisting of an amino acid sequence of SEQ ID NO: 10, a VL CDR2 consisting of an amino acid sequence of SEQ ID NO: 11, a VL CDR3 consisting of an amino acid sequence of SEQ ID NO: 12.In an embodiment, the PD-L1 targeting moiety that specifically binds PD-L1 comprises a heavy chain variable region consisting of an amino acid sequence of SEQ ID NO: 13 and a light chain variable region consisting of an amino acid sequence of SEQ ID NO: 14, and the 4-1BB targeting moiety that specifically binds 4-1BB comprises a heavy chain variable region consisting of an amino acid sequence of SEQ ID NO: 15 and a light chain variable region consisting of an amino acid sequence of SEQ ID NO: 16.

[0037] NameSequenceSEQ ID NO.PD-L1 targeting moietyVHEVQLVESGGGLVQPGGSLRLSCAASGFTFSSYDMSWVRQAPGKSLEWVATISDAGGYIYYRDSVKGRFTISRDNAKNSLYLQMNSLRDEDTAVYICARELPWRYALDYWGQGTTVTVSS13VLDIQMTQSPSSLSASVGDRVTITCKASQDVTPAVAWYQQKPGKAPKLLIYSTSSRYTGVPSRFSGSGSGTDFTFTISSLQPEDIATYYCQQHYTTPLTFGQGTKLEIK144-1BB targeting moietyVHEVQLLESGGGLVQPGGSLRLSCAASGFTFSSYDMSWVRQAPGKCLEWVSWISYSGGSIYYADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCARDAQRNSMREFDYWGQGTLVTVSS15VLQSVLTQPPSASGTPGQRVTISCSGSSSNIGNNYVTWYQQLPGTAPKLLIYADSHRPSGVPDRFSGSKSGTSASLAISGLRSEDEADYYCATWDYSLSGYVFGCGTKLTVL16

[0038] In an embodiment, the bispecific antibody may comprise a full-length anti-PD-L1 antibody, an antigen-binding fragment (e.g., scFv) of an anti-4-1BB antibody, and a peptide linker there between.

[0039] In an embodiment, the anti-PD-L1 / anti-4-1BB bispecific antibody described in WO 2020 / 107715 having the sequences in the table below (table 3) was prepared in the form of a full-length IgG X scFv in which anti-PD-L1 antibody is placed in full IgG form and anti-4-1BB antibody is placed in scFv form.

[0040] NameSequence (N'→C')SEQ ID NO.anti-PD-L1 moietyHeavy chainEVQLVESGGGLVQPGGSLRLSCAASGFTFSSYDMSWVRQAPGKSLEWVATISDAGGYIYYRDSVKGRFTISRDNAKNSLYLQMNSLRDEDTAVYICARELPWRYALDYWGQGTTVTVSSASTKGPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDKKVEPKSCDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSREEMTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGK17LinkerGGGGSGGGGSGGGGS18anti-4-1BB moietyVLQSVLTQPPSASGTPGQRVTISCSGSSSNIGNNYVTWYQQLPGTAPKLLIYADSHRPSGVPDRFSGSKSGTSASLAISGLRSEDEADYYCATWDYSLSGYVFGCGTKLTVL16LinkerGGGGSGGGGSGGGGSGGGGS19VHEVQLLESGGGLVQPGGSLRLSCAASGFTFSSYDMSWVRQAPGKCLEWVSWISYSGGSIYYADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCARDAQRNSMREFDYWGQGTLVTVSS15anti-PD-L1 moietyLight chainDIQMTQSPSSLSASVGDRVTITCKASQDVTPAVAWYQQKPGKAPKLLIYSTSSRYTGVPSRFSGSGSGTDFTFTISSLQPEDIATYYCQQHYTTPLTFGQGTKLEIKRTVAAPSVFIFPPSDEQLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYACEVTHQGLSSPVTKSFNRGEC20

[0041] Treatment methods

[0042] The present disclosure provides treatment methods useful for treating a cancer patient. For example, a treatment method of the present disclosure includes administering a therapeutically effective amount of the anti-PD-L1 / anti-4-1BB bispecific antibody or antigen-binding fragment thereof to a patient. As such, by administering the anti-PD-L1 / anti-4-1BB bispecific antibody or antigen-binding fragment thereof to a patient, a therapeutic effect may be provided to a cancer patient or a patient in need of the method of treatment of the present disclosure.

[0043] In one aspect, provided herein is a method of treating a cancer in a subject in need thereof, comprising administering a therapeutically effective amount of the anti-PD-L1 / anti-4-1BB bispecific antibody or antigen binding fragment thereof to the subject.

[0044] In an embodiment, the anti-PD-L1 / anti-4-1BB bispecific antibody used for the method of the present disclosure may comprise a PD-L1 targeting moiety that specifically binds to PD-L1 and a 4-1BB targeting moiety that specifically binds to4-1BB, wherein the PD-L1 targeting moiety comprises a VH CDR1 consisting of an amino acid sequence of SEQ ID NO: 1, a VH CDR2 consisting of an amino acid sequence of SEQ ID NO: 2, a VH CDR3 consisting of an amino acid sequence of SEQ ID NO: 3, a VL CDR1 consisting of an amino acid sequence of SEQ ID NO: 4, a VL CDR2 consisting of an amino acid sequence of SEQ ID NO: 5, a VL CDR3 consisting of an amino acid sequence of SEQ ID NO: 6, and wherein the 4-1BB targeting moiety comprises a VH CDR1 consisting of an amino acid sequence of SEQ ID NO: 7, a VH CDR2 consisting of an amino acid sequence of SEQ ID NO: 8, a VH CDR3 consisting of an amino acid sequence of SEQ ID NO: 9, a VL CDR1 consisting of an amino acid sequence of SEQ ID NO: 10, a VL CDR2 consisting of an amino acid sequence of SEQ ID NO: 11, a VL CDR3 consisting of an amino acid sequence of SEQ ID NO: 12.

[0045] In an embodiment, the anti-PD-L1 / anti-4-1BB bispecific antibody used for the method of the present disclosure may comprise the PD-L1 targeting moiety comprising a heavy chain variable region consisting of an amino acid sequence of SEQ ID NO: 13 and a light chain variable region consisting of an amino acid sequence of SEQ ID NO: 14, and the 4-1BB targeting moiety comprising a heavy chain variable region consisting of an amino acid sequence of SEQ ID NO: 15 and a light chain variable region consisting of an amino acid sequence of SEQ ID NO: 16.

[0046] Types of cancer that can be treated by using the treatment method of the present disclosure are not particularly limited, but in an embodiment, the cancer may be a solid cancer. In an embodiment, the treatment method of the present disclosure may be used for treating progressive locally advanced (unresectable) or metastatic solid tumor.

[0047] In an embodiment, the treatment method of the present disclosure may be used for treating cancer which is selected from the group consisting of nasopharyngeal cancer, head and neck cancer, head and neck squamous cell carcinoma, esophageal cancer, ovarian cancer, melanoma, liver cancer, gastric cancer, breast cancer, colon cancer, colorectal cancer, prostate cancer, bone cancer, liver cancer, hepatocellular carcinoma, lung cancer, small cell lung cancer, non-small cell lung cancer, urothelial bladder cancer, colon cancer, pancreatic cancer, thyroid cancer, renal cancer, renal cell carcinoma, cholangiocarcinoma, bile duct cancer, Merkel cell carcinoma, brain cancer, cervical cancer, endometrial cancer, bladder cancer, squamous cell carcinoma, and adrenal gland cancer.

[0048] In an embodiment, the treatment method of the present disclosure may be used for treating cancer which is selected from the group consisting of nasopharyngeal cancer, head and neck cancer, head and neck squamous cell carcinoma, esophageal cancer, ovarian cancer, gastric cancer, melanoma, liver cancer, hepatocellular carcinoma, and lung cancer.

[0049] To achieve a desired therapeutic effect through the treatment method of the present disclosure, repeated administration of the bispecific antibody of the present disclosure may be required, and in this case, a patient may be administered a target dose of the bispecific antibody and monitored, and may be repeatedly administered until a therapeutic effect is achieved. In an embodiment, the present disclosure provides a treatment method including administering of the bispecific antibody to a patient at least once. In an embodiment, provided is a treatment method including administering the bispecific antibody of the present disclosure to a patient repeatedly once every two weeks at regular intervals. In some embodiments, provided is a treatment method including administering the bispecific antibody of the present disclosure to a patient repeatedly at a predetermined administration cycle. In an embodiment, provided is a treatment method including administering the bispecific antibody of the present disclosure to a patient repeatedly every two weeks in one administration cycle defined as 28 days, wherein the administering may be performed on Day 1 and Day 15 of the 28-day cycle. In some embodiments, after the end of the administration cycle, another administration cycle may follow optionally with a rest period. In an embodiment, the administering of the bispecific antibody according to the treatment method of the present disclosure may be continued until the patient achieves a confirmed CR such that no further treatment is necessary, the disease is in progression despite treatment, or unacceptable side effects occur such that treatment is no longer considered necessary.

[0050] The bispecific antibody of the present disclosure may be administered in a suitable manner to achieve a desired therapeutic effect, and the administration may be accomplished by one or more techniques well known in the art. In an embodiment, the bispecific antibody of the present disclosure can be administered intravenously.

[0051] To achieve a desired therapeutic effect in a patient with the treatment method of the present disclosure, a therapeutically effective amount of the bispecific antibody needs to be administered to a subject. In an embodiment, the bispecific antibody of the present disclosure may be administered in a body weight-based dose manner.

[0052] In an embodiment, the bispecific antibody may be administered at a dose of about 0.3 mg / kg to about 15 mg / kg at a time. Preferably, the bispecific antibody may be administered at a dose of about 3 mg / kg to about 10 mg / kg at a time, at a dose of about 3 mg / kg to about 7.5 mg / kg at a time, or at a dose of about 3 mg / kg to about 7 mg / kg at a time. Most preferably, the bispecific antibody may be administered at a dose of about 3 mg / kg to 5 mg / kg at a time or at a dose of about 5 mg / kg to 7 mg / kg at a time.

[0053] In an embodiment, the bispecific antibody of the present disclosure may be administered, at a time, at a dose of about 0.3 mg / kg, about 1 mg / kg, about 2 mg / kg, about 3 mg / kg, about 5 mg / kg, about 7 mg / kg, about 7.5 mg / kg, about 10 mg / kg, or about 15 mg / kg. Preferably, the bispecific antibody of the present disclosure may be administered, at a time, at a dose of about 3 mg / kg, about 5 mg / kg, or about 7 mg / kg.

[0054] In some embodiments, the bispecific antibody of the present disclosure may be administered at a flat dose. In an embodiment, the bispecific antibody may be administered at a dose of about 0.7 mg to about 7 mg at a time. Preferably, the bispecific antibody may be administered, at a time, at a dose of about 0.7 mg, about 2 mg, or about 7 mg.

[0055] In an embodiment, the bispecific antibody of the present disclosure may be administered every two weeks.

[0056] In an embodiment, the bispecific antibody may be administered at a dose of about 0.3 mg / kg to about 15 mg / kg once every two weeks. Preferably, the bispecific antibody may be administered at a dose of about 3 mg / kg to about 10 mg / kg once every two weeks, at a dose of about 3 mg / kg to about 7.5 mg / kg once every two weeks, or at a dose of about 3 mg / kg to about 7 mg / kg once every two weeks. Most preferably, the bispecific antibody may be administered at a dose of about 3 mg / kg to 5 mg / kg once every two weeks or at a dose of about 5 mg / kg to 7 mg / kg once every two weeks.

[0057] In some embodiments, the bispecific antibody of the present disclosure may be administered at a dose of about 0.7 mg to about 7 mg once every two weeks, preferably, at a dose of about 0.7 mg, about 2 mg, or about 7 mg once every two weeks.

[0058] The treatment methods of the present disclosure show a therapeutic effect in a cancer patient who lacks suitable treatment options. In this regard, the treatment method of the present disclosure may provide therapeutic benefits to a cancer patient. The present disclosure may provide a method of treating cancer by administering the bispecific antibody to a patient who has previously been treated with a existing cancer therapy. In addition, the present disclosure may provide a method of treating cancer by administering the bispecific antibody to a patient having cancer relapsed and / or refractory to existing cancer therapy.

[0059] A subject of the present disclosure may have received at least one existing cancer therapy to treat cancer, and may have experienced disease progression at or after the time of receiving last existing cancer therapy. The existing cancer therapy is not particularly limited, but may include systemic anticancer treatment.

[0060] In an embodiment, the treatment method of the present disclosure may be used in the subject received at least one existing cancer therapy and / or having cancer relapsed and / or refractory to at least one existing cancer therapy.

[0061] In an embodiment, the existing cancer therapy may be one or more types of treatment. In an embodiment, the existing cancer therapy may comprise one or more therapy selected from surgery, cytotoxic therapy, chemotherapy, immunotherapy, radiotherapy, targeted therapy, or combination thereof. In an embodiment, the existing cancer therapy may comprise one or more therapy selected from surgery, cytotoxic therapy, chemotherapy, targeted therapy, immunotherapy, radiotherapy, or combination thereof.

[0062] In an embodiment the existing cancer therapy may include at least one chemotherapy. In an embodiment, the chemotherapy may include a platinum-based compound or combination thereof. In an embodiment, the platinum-based compound is not particularly limited, and for example, may include carboplatin, nedaplatin, cisplatin, or oxaliplatin.

[0063] In an embodiment the existing cancer therapy may include at least one immunotherapy. In an embodiment, the immunotherapy may comprise administrating at least one checkpoint inhibitor to a subject. The checkpoint inhibitor is not particularly limited, and for example, may include a PD-1 inhibitor and / or a PD-L1 inhibitor. In an embodiment, the immunotherapy may comprise administrating at least one checkpoint inhibitor selected from a group consisting of a PD-1 inhibitor and a PD-L1 inhibitor to a subject.

[0064] In an embodiment, the method of the present disclosure may be applied as a second line, third line, or later line of treatment. The term "line of treatment" refers to the order of treatments with different medications or other therapies received by a patient. A first-line therapy is treatment given first, whereas a second-line therapy or a third-line therapy is provided after the first-line therapy or the second-line therapy, respectively. Therefore, the first-line therapy is the first treatment for a disease or symptom. In a cancer patient, the first-line therapy may include surgery, cytotoxic therapy, chemotherapy, targeted therapy, immunotherapy, radiotherapy, or combination thereof. Typically, a patient may be offered a follow-up therapy (second-line therapy or third-line therapy) when the patient has failed to achieve a positive clinical outcome, has showed only a poor response to the first- or second-line therapy, or has achieved a positive clinical outcome but experienced a relapse as being refractory to the therapy that initially elicited a positive response. In some embodiments, the treatment method of the present disclosure may be applied as a first-line therapy.

[0065] In an embodiment, a subject of the present disclosure may have received at least one existing cancer therapy to treat cancer, and at the time of the last existing cancer therapy or thereafter, the subject may have experienced disease progression and / or metastasis, such as disease progression and / or metastasis determined by histological examination, cytological examination, and / or radiography. In an embodiment, the subject of the present disclosure may not have obtained therapeutic benefits at the time of the last existing cancer therapy or thereafter. In an embodiment, the subject of the present disclosure may have obtained therapeutic benefits at the time of the last existing cancer therapy, but thereafter, may have experienced disease progression and / or metastasis. In an embodiment, the subject of the present disclosure may have received up to four systemic anti-cancer therapies to treat cancer. In an embodiment, the systemic anti-cancer treatment may include chemotherapy, immunotherapy, targeted therapy, or combination thereof.

[0066] The treatment methods of the present disclosure may provide therapeutic benefits to a cancer patient, wherein the therapeutic benefits may include, although not particularly limited thereto, delaying tumor growth, reducing tumor size, or completely disappearing tumor. Among patients treated with the treatment method of the present disclosure, the ORR of the patients having cancer relapsed and / or refractory to the treatment methods was 26.9%, and the clinical benefit rate was accordingly 69.2%. These results suggest that the treatment method of the present disclosure may provide prominent therapeutic benefits to a cancer patient.

[0067] In an aspect, the present disclosure may provide a method of treating a cancer in a subject comprising (a) selecting a subject with a cancer; and (b) administering to the subject in need thereof a therapeutically effective amount of an anti-PD-L1 / anti-4-1BB bispecific antibody to the subject.

[0068] In another aspect, the present disclosure may provide a use of an anti-PD-L1 / anti-4-1BB bispecific antibody in preparing a medicament for treating cancer in a subject in need thereof according to the method provided herein.

[0069] In yet another aspect, the present disclosure may provide an article of manufacture, comprising: (1) an anti-PD-L1 / anti-4-1BB bispecific antibody or pharmaceutical composition comprising thereof, and (2) a package insert which suggests administration of the anti-PD-L1 / anti-4-1BB bispecific antibody.

[0070] The detailed components and explanations provided relates to the treatment method above may be also applied to the use of the anti-PD-L1 / anti-4-1BB bispecific antibody and the article of manufacture.

[0071] Pharmaceutical compositions

[0072] The present disclosure provides a pharmaceutical composition for administration to a patient in need thereof for treating cancer.

[0073] In one aspect, provided herein is a pharmaceutical composition for the method provided herein, comprising a therapeutically effective amount of the anti-PD-L1 / anti-4-1BB bispecific antibody or antigen binding fragment thereof.

[0074] Types of cancer that can be applied to the pharmaceutical composition of the present disclosure are not particularly limited, but in an embodiment, the cancer may be a solid cancer. In an embodiment, the solid tumor may be an unresectable progressive locally advanced tumor, or ametastatic solid tumor. The pharmaceutical composition of the present disclosure may be more useful for a cancer patient who lacks suitable treatment options, and in this regard, the pharmaceutical composition of the present disclosure may provide therapeutic benefits to a cancer patient.

[0075] To achieve a desired therapeutic effect through the pharmaceutical composition of the present disclosure, repeated administration of the pharmaceutical composition of the present disclosure may be required, and in this case, a patient may be administered a target dose of the bispecific antibody and monitored, and may be repeatedly administered until a therapeutic effect is achieved.

[0076] Regarding examples and aspects of the dosage, administration interval, administration method, and administration regimen of the pharmaceutical composition of the present disclosure, the matters described above regarding the treatment methods may be applied same.

[0077] The present disclosure provides the pharmaceutical composition useful for a patient who has previously been treated with the existing cancer therapy. In addition, the present disclosure provides the pharmaceutical composition useful for a patient having cancer relapsed and / or refractory to the existing cancer therapy. Regarding specific examples and aspects of the existing cancer therapy, the matters described regarding the treatment methods may be applied same.

[0078] In an embodiment, the pharmaceutical composition of the present disclosure may be used as a second-line, third-line, or higher-line treatment. In some embodiments, the treatment method of the present disclosure may be applied as a first-line therapy.

[0079] The pharmaceutical composition including the bispecific antibody of the present disclosure may provide therapeutic benefits to a cancer patient. The therapeutic benefits are not particularly limited, but may include delaying tumor growth, reducing tumor size, or completely disappearing tumor.

[0080] FIG. 1 is a graph showing a tumor killing effect of ABL503 in patient-derived Atezolizumab (anti-PD-L1 antibody)-insensitive lung cancer organoids.

[0081] FIG. 2 is a graph showing pharmacokinetic profiles of ABL503 administered intravenously to cancer patients. Specifically, the graph shows the blood concentrations of ABL503 measured in cancer patients administered ABL503.

[0082] FIG. 3 is a graph showing pharmacodynamic profiles of ABL503 administered intravenously to cancer patients. Specifically, the graph shows the concentrations of soluble 4-1BB, which is a pharmacodynamic biomarker of ABL503, measured in the serum of patients administered ABL503 for 56 days after the date of administration.

[0083] FIG. 4 is a graph showing the number of days of administration of ABL503 and therapeutic response to ABL503.

[0084] FIG. 5 is a graph showing progression-free survival periods of patients administered ABL503 repeatedly at a dose of 3 mg / kg or 5 mg / kg.

[0085] FIG. 6 is a graph showing best changes (represented in %) in tumor size from the baseline, in patients administered ABL503 repeatedly at various doses. A significant reduction in tumor size was observed in patients administered repeatedly at doses of 3 mg / kg and 5 mg / kg.

[0086] FIG. 7 shows photographs showing changes in tumor size after administration discontinuation in the patient who achieved complete response by administration of ABL503.

[0087] FIG. 8 is a graph showing changes in the amount of memory T cells in the patient who achieved complete response by administration of ABL503.

[0088] The following examples are put forth so as to provide those of ordinary skill in the art with a complete disclosure and description of how to make and use the present disclosure, and are not intended to limit the scope of what the inventors regard as their invention nor are they intended to represent that the experiments below are all or the only experiments performed. Efforts have been made to ensure accuracy with respect to numbers used (e.g. amounts, temperature, etc.) but some experimental errors and deviations should be accounted for. Unless indicated otherwise, parts are parts by weight, molecular weight is weight average molecular weight, temperature is in degrees Centigrade, and pressure is at or near atmospheric.

[0089] Example 1 Preparation of anti-PD-L1 / anti-4-1BB bispecific antibodies

[0090] ABL503 is an anti-PD-L1 / anti-4-1BB bispecific antibody having an anti-PD-L1 antibody in a IgG1 form and two anti-4-1BB antibodies in a scFv form which are connected to the C-terminal of the heavy chains of the anti-PD-L1 antibody, respectively. The anti-PD-L1 IgG has a heavy chain sequence of SEQ ID NO: 17 and a light chain sequence of SEQ ID NO: 20. The anti-4-1BB scFv has a variable light chain sequence of SEQ ID NO: 16, the linker sequence of SEQ ID NO: 19, and a variable heavy chain sequence of SEQ ID NO: 15. The linker connecting IgG and scFv has the sequence of SEQ ID NO: 18. The preparation of such ABL503 is also described in WO 2020 / 107715, which is incorporated by reference herein.

[0091] Example 2 Cancer organoid killing effect of ABL503 in non-responders of Atezolizumab

[0092] To evaluate the efficacy of ABL503 in non-responders of Atezolizumab, 4 patient-derived PD-L1 blockade resistant lung cancer organoids were incubated with donor matching T cells treated with test articles at 0 to 10 nM for 3 days (Organoid sciences, Ltd.). Then, the area of damaged organoids stained with Hoechst33342 (Thermo, H-1339) was analyzed using High Contents Screening (HCS) device, Cytation5 (Biotek). The percentage of specific killing was calculated as follows:

[0093] ● (Formula 1) Organoid damage at specific concentration=1-(72 hour(hr) treated organoid area / 0 hr organoid area)

[0094] ● (Formula 2) % of killing effect at specific concentration=(Treated organoid damage / Non-treated organoid damage)x100

[0095] As shown in FIG. 1, ABL503 exhibited a significant tumor killing effect in patient-derived Atezolizumab-insensitive lung cancer organoids when compared to control group or Atezolizumab group. P-values were determined by t-test (** p<0.01, * p<0.05). This result shows that ABL503 reinvigorated PD-1 blockade-unresponsive exhausted CD8+ tumor infiltrating lymphocytes (TILs).

[0096] Example 3 Clinical study of ABL503 in subjects with any progressive locally advanced (unresectable) or metastatic solid tumors

[0097] The open-label, multicenter, multiple-dose, dose-escalation and dose-expansion study of ABL503 was performed to evaluate the safety, tolerability, pharmacokinetics, immunogenicity, antitumor activity, and the pharmacodynamic effect of ABL503 in subjects with any progressive locally advanced (unresectable) or metastatic solid tumors relapsed and / or refractory to the last line of anti-cancer therapy.

[0098] Study design

[0099] A treatment cycle was defined as 28 days in the clinical study. ABL503 was intravenously administered once every two weeks to subjects on Day 1 and Day 15 of every 28-day cycle.

[0100] The clinical study comprised three separated parts, a dose-escalation part, a dose-expansion part and tumor-expansion part.

[0101] In the dose-escalation part, ABL503 was evaluated across 10 doses. Flat dosing was followed by body weight-based dosing as follows:

[0102] ● Flat dose: 0.7 mg, 2 mg, and 7 mg.

[0103] ● Body weight-based dose: 0.3 mg / kg, 1 mg / kg, 2 mg / kg, 3 mg / kg, 5 mg / kg, 7 mg / kg and 10 mg / kg.

[0104] The dose for the dose-expansion part was determined as 3 mg / kg and 5 mg / kg based on the pharmacokinetic(PK) / pharmacodynamic(PD) modeling and outcomes from the dose-escalation part. In the dose-expansion part, safety, tolerability, preliminary antitumor activity, immunogenicity, PK and PD activity of ABL503 were evaluated.

[0105] All subjects participated in the study satisfied with all inclusion criteria before the first administration of ABL503. Any subject met one or more exclusion criteria was excluded from the study. Particular inclusion criteria and exclusion criteria for the clinical study are shown in Table 4.

[0106] List of inclusion and exclusion criteriaInclusionCriteria- Histologically and / or cytologically confirmed diagnosis of any progressive locally advanced (unresectable) or metastatic solid tumors that have relapsed or are refractory following the last line of treatment, for which prior standard therapy has been ineffective, standard therapy does not exist, or is not considered appropriate.- Dose-escalation part: Histologically and / or cytologically confirmed diagnosis of any progressive locally advanced (unresectable) or metastatic solid tumors that have relapsed or are refractory following the last line of treatment, for which prior standard therapy has been ineffective, standard therapy does not exist, or is not considered appropriate.- Dose-expansion part: (i) Histologically and / or cytologically confirmed diagnosis of any progressive locally advanced (unresectable) or metastatic solid tumors that have relapsed or are refractory following the last line of treatment, for which prior standard therapy has been ineffective, standard therapy does not exist, or is not considered appropriate, (ii) Received a maximum of 4 prior systemic anticancer treatment regimens (inclusive of chemotherapy, immunotherapy, and targeted therapy regimens) for advanced or recurrent / metastatic disease, and (iii) CPS or TPS is equal to or more than 1.- With AE(s) excluding alopecia or Grade 2 toxicities that are deemed stable or irreversible (e.g., peripheral neuropathy) from prior therapy that have improved to Grade 1 or the baseline grade more than 14 days prior to the first administration of the study drug.- Adequate hematologic, hepatic, and renal functions confirmed based on the screening laboratory tests and reconfirmed with additional safety laboratory tests performed within 72 hours prior to the first administration of ABL503.Exclusion Criteria:- Prior anticancer monoclonal antibody treatment or investigational therapy within 28 days prior to the first administration of study drug or has not recovered (i.e., ≤ Grade 1 or at baseline grade) from AEs due to previously administered agent more than 14 days prior to ABL503 administration.- Prior chemotherapy or radiation therapy within 2 weeks or targeted small molecule therapy within 5 half-lives prior to the first administration of study drug or has not recovered (i.e., ≤ Grade 1 or at baseline grade) from AEs due to previously administered agent more than 14 days prior to ABL503 administration.- Requiring or received systemic steroid therapy or any other immunosuppressive therapy within 14 days prior to study drug administration.- Risk factors for bowel obstruction or bowel perforation (including but not limited to a history of acute diverticulitis, intra-abdominal abscess, and abdominal carcinomatosis).- Discontinued from prior immunomodulatory therapy due to any intolerable immune-related adverse events (IrAEs) requiring systemic steroid treatment.- History of drug-induced pneumonitis (interstitial lung disease) or currently has pneumonitis.- Received prior treatment with an anti-4-1BB antibody

[0107] Patient characteristics and demographics

[0108] 53 subjects were enrolled in the clinical study. Among them, 34 subjects were enrolled in the dose-escalation part, and 19 subjects were enrolled in the dose-expansion part. All subjects were heavily pretreated with anti-cancer therapy before the enrollment. Particularly, 34.0% of the subjects (18 of 53 subjects) had received four or more prior lines of systemic anti-cancer therapy. Furthermore, 56.6% of the subjects (30 of 53 subjects) had received anti-PD-1 or anti-PD-L1 inhibitor before the enrollment (see Table 5).

[0109] Baseline demographics and clinical characteristicsABL503 monotherapy DemographyAll patients (N=53)Female, n(%)18 (34.0)Male, n(%)35 (66.0)ECOG performance status, n(%)021 (39.6)132 (60.4)Prior lines of treatment111 (20.8)28 (15.1)316 (30.2)≥ 418 (34.0)Prior treatment with PD-(L)1 inhibitor, n(%)30 (56.6)

[0110] Safety results

[0111] Forty subjects (40 of 53 subjects, 75.5%) represented at least one treatment-related adverse event (TRAE). Most common TRAEs were ALT (alanine aminotransferase) or AST (aspartate aminotransferase) increase. Cytokine release syndrome (CRS) did not occurred in any subject received ABL503 and one subject received 5 mg / kg of ABL503 showed infusion-related reaction (grade 2). Treatment of ABL503 was discontinued due to TRAEs in 9 subjects (17% of 53 subjects). Maximal Tolerated Dose for biweekly regimen was determined to 7 mg / kg based on the outcomes from the dose-escalation part. The probability of DLT (dose-limiting toxicity) rate over 30% is 0.14 for the subject group receiving 7 mg / kg of ABL503. The results are shown in Table 6 below.

[0112] TRAE occurring in ≥ 10% of patientsABL503 monotherapy DemographyAll patients (N=53)All grades, n(%)Grade ≥ 3, n(%)Any TRAE40 (75.5)22 (41.5)TRAE occurring in≥10% of patientsAlanine aminotransferase increased17 (32.1)12 (22.6)Aspartate aminotransferase increased16 (30.2)11 (20.8)Pyrexia8 (15.1)1 (1.9)Nausea7 (13.2)-Rash7 (13.2)2 (3.8)Fatigue6 (11.3)1 (1.9)Platelet count decreased6 (11.3)1 (1.9)

[0113] Pharmacokinetics and immunogenicity results

[0114] PK profiles (AUC, Cmax) of ABL503 were dose proportionally increased. In subject groups receiving 2 mg / kg or more of ABL503, the half-life ranged from 3.6 to 5.2 days (see FIG. 2). The results are shown in Table 7 below.

[0115] Pharmacokinetics parameters of ABL503Parameter3 mg / kg, n=155 mg / kg. n=16AUC336h, hr*ug / mL(min, max)7,280 (1810, 14400)13,400 (7010, 22800)Cmax, ug / mL(min, max)69.2 (21, 118)118 (70, 180)Half life, hr(min, max)81.8 (40.2, 143)103 (36.8, 204)

[0116] In the subject groups receiving 3 and 5 mg / kg of ABL503, one subject in each groups presented induced anti-drug antibody (ADA) but no significant change of ABL503 exposure was observed.

[0117] Soluble 4-1BB in peripheral serum sample

[0118] Intravenous administration of ABL503 increased serum soluble 4-1BB level dose-dependently, and the result demonstrates target engagement of ABL503. Serum soluble 4-1BB level was increased and sustained for more than 56 days in subject groups receiving equal to or more than 1 mg / kg of ABL503. This data supports the every two-weeks dosing interval. Especially, increased soluble 4-1BB level was stably sustained in the subject groups receiving 3 and 5 mg / kg of ABL503 (see FIG. 3). The result supports that 3 and 5 mg / kg of ABL503 is an optimal dose for achieving and sustaining therapeutic efficacy of ABL503. Furthermore, ABL503 significantly increased proliferating (Ki67+) T cells and effector memory T cells. Increase of proliferating IFN-γ, TNF-α and IP-10 (CXCL10) were observed also.

[0119] Efficacy result

[0120] (1) Duration Of Response (DOR) and Progression Free Survival (PFS)

[0121] Objective responses were observed in 7 out of 44 efficacy-evaluable patients. Treatment Duration was 14.0 weeks for subject receiving 3 mg / kg of ABL503 and 15.2 weeks for subject receiving 5 mg / kg of ABL503. Progression Free Survival period was calculated as 15.8 weeks for subject receiving 3 mg / kg of ABL503 and 15.6 weeks for subject receiving 5 mg / kg of ABL503. The results are shown in Figs. 4 and 5.

[0122] (2) Objective Response Rate (ORR) and Clinical Benefit Rate (CBR)

[0123] 26 subjects were treated with ABL503 at a dose level of 3 or 5 mg / kg. In the groups of receiving 3 or 5 mg / kg of ABL503, tumor size significantly decreased in 7 subjects (see FIG. 6) The objective response rate (ORR) of 3 or 5 mg / kg of ABL503 monotherapy was calculated as 26.9% (7 out of 26 subjects) and the clinical benefit rate (CBR) was calculated as 69.2% (18 out of 26 subjects). The results are shown in Table 8.

[0124] Efficacy profiles of ABL503ABL503 monotherapy efficacy profile3 mg / kg (N=14)5 mg / kg (N=12)Sum (N=26)Overall response rate, n(%)4 (28.5%)3 (25.0%)7 (26.9%)Clinical benefit rate, n(%)9 (64.2%)9 (75.0%)18 (69.2%)Complete response1 (7.1%)0 (0.0%)1 (3.8%)Partial response3 (21.4%)3 (25.0%)6 (23.1%)Stable disease5 (35.7%)6 (50.0%)11 (42.3%)Progressive disease5 (35.7%)3 (25.0%)8 (30.8%)Progression Free Survival (median), weeks15.815.615.6Treatment Duration (median), weeks14.015.215.2

[0125] (3) Case Report: complete response in heavily pre-treated ovarian cancer

[0126] Complete response (CR) was observed during dose-escalation study in one subject with ovarian cancer who had received 7 prior lines of treatment (1L: Carboplatin / Paclitaxel (Docetaxel), 2L: Bevacizumab. 3L: Doxorubicin, 4L: Topotecan / Bevacizumab, 5L: NaPi2b targeting ADC, 6L: Pembrolizumab / MDM2 inhibitor, 7L: bi-sialidase) before participated in the clinical trial.

[0127] In the clinical trial, the subject achieved sustained tumor regression over 6 months, even after treatment discontinuation (see FIG. 7). In addition, induced effector memory T cells by ABL503 were observed (see FIG. 8). It is believed to be linked to the observed sustained tumor regression and expansion of effector memory T cell induced by ABL503.

[0128] 71.4% of responders (5 out of 7 subjects) had received prior anti-PD-(L)1 inhibitors and all were relapsed or refractory to anti-PD-(L)1 inhibitors.

[0129] The results from the clinical study indicate that 3 mg / kg and 5 mg / kg of ABL503 may provide therapeutic benefit for the subject having cancer refractory and / or relapsed to existing cancer therapy, especially comprising the checkpoint inhibitor.

Claims

1.A method of treating a cancer in a subject in need thereof, comprising administering a therapeutically effective amount of an anti-PD-L1 / anti-4-1BB bispecific antibody or antigen binding fragment thereof to the subject.2.The method of claim 1, wherein the anti-PD-L1 / anti-4-1BB bispecific antibody comprises a PD-L1 targeting moiety that specifically binds PD-L1 and a 4-1BB targeting moiety that specifically binds 4-1BB, wherein the PD-L1 targeting moiety comprises a VH CDR1 consisting of an amino acid sequence of SEQ ID NO: 1, a VH CDR2 consisting of an amino acid sequence of SEQ ID NO: 2, a VH CDR3 consisting of an amino acid sequence of SEQ ID NO: 3, a VL CDR1 consisting of an amino acid sequence of SEQ ID NO: 4, a VL CDR2 consisting of an amino acid sequence of SEQ ID NO: 5, a VL CDR3 consisting of an amino acid sequence of SEQ ID NO: 6, and wherein the 4-1BB targeting moiety comprises a VH CDR1 consisting of an amino acid sequence of SEQ ID NO: 7, a VH CDR2 consisting of an amino acid sequence of SEQ ID NO: 8, a VH CDR3 consisting of an amino acid sequence of SEQ ID NO: 9, a VL CDR1 consisting of an amino acid sequence of SEQ ID NO: 10, a VL CDR2 consisting of an amino acid sequence of SEQ ID NO: 11, a VL CDR3 consisting of an amino acid sequence of SEQ ID NO: 12.3.The method of claims 1 to 2, wherein the PD-L1 targeting moiety that specifically binds PD-L1 comprises a heavy chain variable region consisting of an amino acid sequence of SEQ ID NO: 13 and a light chain variable region consisting of an amino acid sequence of SEQ ID NO: 14, and the 4-1BB targeting moiety that specifically binds 4-1BB comprises a heavy chain variable region consisting of an amino acid sequence of SEQ ID NO: 15 and a light chain variable region consisting of an amino acid sequence of SEQ ID NO: 16.4.The method of claims 1 to 3, wherein the anti-PD-L1 / anti-4-1BB bispecific antibody is administered to the subject at a dose of 0.3 mg / kg to 15 mg / kg.5.The method of claim 4, wherein the anti-PD-L1 / anti-4-1BB bispecific antibody is administered to the subject at a dose of 3 mg / kg to 7 mg / kg.6.The method of claim 5, wherein the anti-PD-L1 / anti-4-1BB bispecific antibody is administered to the subject at a dose of 3 mg / kg or 5 mg / kg.7.The method of claims 1 to 6, wherein the anti-PD-L1 / anti-4-1BB bispecific antibody is administered to the subject once in two weeks.8.The method of claims 1 to 7, wherein the anti-PD-L1 / anti-4-1BB bispecific antibody is intravenously administered to the subject.9.The method of claims 1 to 8, wherein the subject has received at least one existing cancer therapy or has cancer relapsed or refractory to at least one existing cancer therapy.10.The method of claim 9, wherein the existing cancer therapy comprises one or more chemotherapy, immunotherapy, targeted therapy, or combination thereof.11.The method of claim 10, wherein the immunotherapy comprises administering at least one checkpoint inhibitor selected from a group consisting of PD-1 inhibitor and PD-L1 inhibitor to the subject.12.The method of claims 1 to 11, wherein the cancer is progressive locally advanced or metastatic solid tumor.13.The method of claims 1 to 12, wherein the cancer is selected from the group consisting of nasopharyngeal cancer, head and neck cancer, head and neck squamous cell carcinoma, esophageal cancer, ovarian cancer, melanoma, liver cancer, gastric cancer, breast cancer, colon cancer, colorectal cancer, prostate cancer, bone cancer, liver cancer, hepatocellular carcinoma, lung cancer, small cell lung cancer, non-small cell lung cancer, urothelial bladder cancer, colon cancer, pancreatic cancer, thyroid cancer, renal cancer, renal cell carcinoma, cholangiocarcinoma, bile duct cancer, Merkel cell carcinoma, brain cancer, cervical cancer, endometrial cancer, bladder cancer, squamous cell carcinoma, and adrenal gland cancer.14.The method of claim 13, wherein the cancer is selected from the group consisting of nasopharyngeal cancer, head and neck cancer, head and neck squamous cell carcinoma, esophageal cancer, ovarian cancer, gastric cancer, melanoma, liver cancer, hepatocellular carcinoma, and lung cancer.15.A pharmaceutical composition for the method of claims 1 to 14, comprising a therapeutically effective amount of an anti-PD-L1 / anti-4-1BB bispecific antibody or antigen binding fragment thereof.16.A use of an anti-PD-L1 / anti-4-1BB bispecific antibody in preparing a medicament for treating cancer according to the method of claims 1 to 14.17.An article of manufacture, comprising: (1) an anti-PD-L1 / anti-4-1BB bispecific antibody or a pharmaceutical composition comprising thereof, and (2) a package insert which suggests administration of the anti-PD-L1 / anti-4-1BB bispecific antibody according to the method of claims 1 to 14.

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