ADG206 is an activatable prodrug form of a fully human monoclonal antibody (mAb) of the immunoglobulin G1 (IgG1) subclass that specifically targets cluster of differentiation 137 (CD137) (also known as 4-1BB) as a co-stimulatory receptor agonist for the treatment of advanced malignancies.

This is a FIH, Phase 1, open-label, multicenter, sequential dose escalation study to evaluate the safety, tolerability, Pharmacokinetics (PK), and preliminary efficacy of ADG206 in subjects with advanced/metastatic malignancies.

Primary Objective of the study: To assess safety and tolerability at increasing dose levels of ADG206 in subjects with advanced/metastatic solid tumors who have exhausted their treatment alternatives.

Inclusion Criteria:

• Eastern Cooperative Oncology Group (ECOG) performance status ≤1.
• Subjects with advanced or metastatic solid tumors (except thymic tumors), which have progressed after all standard therapies, or no further standard therapies exists.
• At least 1 measurable lesion per Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST 1.1).
• Adequate organ function.
• Woman of childbearing potential must agree to use 2 methods of acceptable contraception from screening until 6 months after the last dose of study drug.
• Male subjects who are sexually active with a female partner of childbearing potential must agree to use a barrier contraception.

Exclusion Criteria:

• Subjects within washout period of other anti-tumor therapies. .
• History of prior malignancy other than the cancer under treatment in the study.
• Major trauma or major surgery within 4 weeks before the first dose of study drug.
• Serious nonhealing wound, ulcer, or bone fracture.
• History of significant immune-mediated AE.
• Central nervous system (CNS) disease involvement.
• Any evidence of underlying severe liver dysfunction.
• Prior organ allograft transplantations or allogeneic bone marrow, cord blood or peripheral blood stem cell transplantation.
• Clinically significant cardiac disease with insufficient cardiac function.
• Evidence of active uncontrolled viral, bacterial, or systemic fungal infection.
• Known positive test result for human immunodeficiency virus (HIV) or acquired immune deficiency syndrome (AIDS).
• Infection of hepatitis B virus (HBV), or hepatitis C virus (HCV) (unless the disease is clinically controlled) .
• History or risk of autoimmune disease.
• Subjects with active severe lung infection or with a history of interstitial lung diseases, noninfectious pneumonitis, active pulmonary tuberculosis, or evidence of active pneumonitis. Clinically significant and unmanageable ascites defined as requiring constant therapeutic paracentesis.
• Any serious underlying issue that would limit compliance with study requirements, impair the ability of the subject to understand informed consent.
• Known hypersensitivity, allergies, or intolerance to immunoglobulins or to any excipient contained in ADG206.
• Pregnant, lactating, or breastfeeding.