Safety, Tolerability and Pharmacokinetics of a Monoclonal Antibody Specific to B-and T-Lymphocyte Attenuator (BTLA) as Monotherapy and in Combination With an Anti-PD1 Monoclonal Antibody for Injection in Subjects With Advanced Malignancies

Inclusion Criteria

• Able to understand and willing to sign the Informed Consent Form;
• 2. Male or female ≥ 18 years;
• 3. Subjects with histologically or cytologically confirmed advanced unresectable or metastatic solid tumor, including lymphoma that have progressed following prior treatment. In Part A, subjects must have received, or be ineligible for or intolerant of all available approved or standard therapies known to confer clinical benefit including immunotherapy, or for whom no standard therapy exists; in Part B, subjects with advanced or metastatic solid tumors, including but not limited to lymphoma, melanoma, NSCLC, or other tumors with agreement of the Sponsor, who must have received at least one line of therapy for advanced or metastatic disease, but are not required to have received all standard therapies known to confer clinical benefit; In Part C, subjects must have received at least one line of therapy for advanced or metastatic disease but are not required to have received all standard therapies known to confer clinical benefit; In Part D, subjects with advanced or metastatic solid tumors that may include but not limited to lymphoma, melanoma, NSCLC, RCC or UC who must have received at least one line of therapy for advanced or metastatic disease, but are not required to have received all standard therapies known to confer clinical benefit.
• 4. Measurable disease per RECISTv1.1 and iRECIST, or RECIL 2017 for lymphoma
• 5. ECOG performance status of 0 or 1 with life expectancy of 3 months in the opinion of the investigator.
• 6. Adequate organ and marrow function, as defined below:
• Hemoglobin 8.0 g/dL within first 2 weeks prior to first dose of TAB004 (are not requiring a transfusion within 14 days prior to dosing)
• Absolute neutrophil count (ANC) 1.0 x 109 /L (1,000 /mm3)
• Absolute lymphocyte count ≥ 0.6 x 109/L (600/mm3)
• Platelet count 75 x 109 /L (75,000 /mm3), and not requiring platelet transfusions within the 5 days prior to dosing
• Total bilirubin ≤ 1.5 x ULN except subjects with documented Gilbert's syndrome who must have a baseline total bilirubin ≤ 3.0 mg/dL
• Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) ≤ 2.5 x ULN; for subjects with hepatic metastases, ALT and AST ≤ 5 x ULN
• Serum creatinine ≤ 1.5 x ULN OR calculated creatinine clearance (CrCl) or 24 hour urine CrCl ≥ 40 mL/minute Cockcroft-Gault formula will be used to calculate CrCl. 24-hour urine CrCl will be derived using the measured creatinine clearance formula
• International normalized ratio (INR) ≤ 2.0 and activated partial thromboplastin time (aPTT) ≤ 1.5 x ULN; applies only to subjects who do not receive therapeutic anticoagulation; subjects receiving therapeutic anticoagulation (such as low-molecular weight heparin or warfarin) should be on a stable dose
• 7. Willingness to provide consent for biopsy samples (In Part A, fresh pre-treatment biopsies will be requested from subjects with safely accessible lesions. For subjects who cannot provide a fresh pre-treatment biopsy, request for the most recent accessible archival specimen will be required. In Part B, C and D, fresh pre-treatment biopsies will be required from subjects with safely accessible lesions. The most recent archival specimens will also be requested).
• 8. Females of childbearing potential who are sexually active with a nonsterilized male partner must use effective contraception from time of screening, and must agree to continue using such precautions for 90 days after the final dose of TAB004 or toripalimab; cessation of birth control after this point should be discussed with a responsible physician. Periodic abstinence, the rhythm method, and the withdrawal method are not acceptable methods of birth control.
• 9. Females of childbearing potential are defined as those who are not surgically sterile (i.e., bilateral tubal ligation, bilateral oophorectomy, or complete hysterectomy) or postmenopausal (defined as at least 12 months with no menses confirmed by follicle-stimulating hormone [FSH] levels. FSH testing will be conducted at the Screening visit to confirm post-menopausal status).
• 10. Subjects must use effective contraception. Nonsterilized males who are sexually active with a female partner of childbearing potential must use effective contraception from Day 1 and for 90 days after receipt of the final dose of TAB004 or toripalimab.

Exclusion Criteria

• Concurrent enrollment in another clinical study, unless it is an observational (non interventional) clinical study or the follow-up period of an interventional study.
• 2. Any concurrent anti-cancer therapy, such as but not limited to chemotherapy, targeted therapy, radiotherapy, immunotherapy, or biologic therapy. Radiation treatment for palliative intent is allowed provided that lesions other than those receiving radiation are available to measure response. Concurrent use of hormones for non-cancer-related conditions (e.g., insulin for type 2 diabetes and hormone replacement therapy) is acceptable. Note: Local treatment of isolated lesions for palliative intent is acceptable (e.g., by local surgery or radiotherapy).
• 3. Receipt of any investigational anticancer therapy within 28 days prior to the first dose of TAB004 or, provided documentable, 5 half lives whichever is shorter, except for lymphoma in which the exclusionary period is 2 weeks for immune checkpoint inhibitors only.
• 4. Current or prior use of immunosuppressive medication within 2 weeks prior to the first dose of TAB004, with the exception of intranasal and inhaled corticosteroids or systemic corticosteroids not to exceed 10 mg/day of prednisone or equivalent.
• 5. Prior exposure to anti-BTLA, or anti-HVEM antibodies for subjects enrolled into Part A and B only; prior treatment with anti-PD-1 or anti-PDL-1is allowed,including toripalimab for all subjects.
• 6. Prior allogeneic bone marrow transplantation or prior solid organ transplantation.
• 7. Subjects with another malignancy, or history or other malignancy within 3 years that is not expected to relapse. Subjects with non-melanomatous skin cancer or cervical cancer that has been curatively surgically resected are eligible.
• 8. Major surgery (as defined by the investigator) within 28 days prior to first dose of TAB004 or has not recovered to at least Grade 1 from adverse effects from such procedure, or anticipation of the need for major surgery during study treatment.
• 9. Unresolved toxicities from prior anticancer therapy, defined as having not resolved to baseline or to NCI-CTCAE v5.0 Grade 0 or 1, or to levels dictated in the inclusion/exclusion criteria with the exception of neuropathies that are stable or improving and alopecia. Subjects with irreversible toxicity that is not reasonably expected to be exacerbated by TAB004 may be included (e.g., hearing loss) after consultation with the medical monitor.
• 10. Active or prior documented autoimmune disease, such as but not limited to systemic lupus erythematosus, multiple sclerosis, inflammatory bowel diseases, rheumatoid arthritis, autoimmune hepatitis, systemic sclerosis, autoimmune vasculitis, autoimmune neuropathies or type 1 insulin-dependent diabetes mellitus. Note: Subjects with the following are not excluded: vitiligo; alopecia; Grave's disease not requiring systemic treatment other than thyroid hormone replacement (within the past 2 years) psoriasis not requiring systemic treatment; controlled celiac disease; subjects with a history of autoimmune hypothyroidism requiring only thyroid hormone replacement therapy; And type 2 diabetes, provided that it is adequately controlled.
• 11. Clinically significant (intracranial, gastrointestinal) bleeding within 2 weeks prior to screening.
• 12. Known history of tuberculosis.
• 13. Subjects with history of or current drug-induced interstitial lung disease or pneumonitis ≥ Grade 2.
• 14. Subjects who have discontinued prior immune therapy due to immune mediated adverse reaction(s).
• 15. Subjects who are known to be human immunodeficiency virus positive.
• 16. Subjects with evidence of hepatitis B or C virus infection, unless their hepatitis is considered to have been cured. (Note that subjects with prior hepatitis B virus infection must have HBV viral load < 100 IU/mL before study enrollment, and must be treated according to local standards; hepatitis C virus infection must have, before study enrollment, no detectable viral load and must be treated according to local standards).
• 17. Active or prior documented inflammatory bowel disease (e.g., Crohn's disease, ulcerative colitis). Infection-related bowel inflammation, such as Clostridium difficile colitis, is not excluded provided that it has been fully resolved for ≥ 6 weeks.
• 18. History of anaphylaxis, or eczema that cannot be controlled with topical corticosteroids asthma.
• 19. Adult asthma that is moderate or severe, or asthma that has required: hospitalization in the last 2 years; invasive mechanical ventilation ever; systemic corticosteroids in the past year for exacerbations; or more than two short acting beta agonist (e.g., albuterol) administrations per month for breakthrough asthma symptoms. A history of childhood asthma or the presence of mild adult asthma that at baseline has symptoms that can be controlled well with inhaled corticosteroids or short acting beta agonists will not be excluded.
• 20. Uncontrolled intercurrent illness including, but not limited to, ongoing or active infection, symptomatic congestive heart failure according to New York Heart Association Functional Classification ≥ 3, uncontrolled hypertension, unstable angina pectoris, cardiac arrhythmia, active peptic ulcer disease or gastritis, or psychiatric illness/social situations that would limit compliance with study requirements, substantially increase risk of incurring adverse events from TAB004, or compromise the ability of the subject to give written informed consent.
• 21. Untreated central nervous system and leptomeningeal metastases or requiring ongoing treatment for these metastases, including corticosteroids. Subjects with previously treated brain metastases may participate provided they are clinically stable for at least 28 days prior to study entry, have no evidence of new or enlarging metastases, and are off steroids.
• 22. Receipt of live attenuated vaccination within 28 days prior to study entry or within 30 days of receiving TAB004.
• 23. Any condition or treatment or diagnostic test that, in the opinion of the investigator or sponsor, would interfere with evaluation of TAB004 or interpretation of subject safety or study results.
• 24. Pregnancy or breast feeding women.