A Study of AK104 in Subjects With Locally Advanced Unresectable or Metastatic MSI-H/dMMR Solid Tumors

Inclusion Criteria: * Have signed written informed consent form voluntarily. * Male or female, age ≥ 18 years on the day of signing informed consent form. * ECOG of 0 or 1. * Estimated life expectancy of ≥3 months. * Histologically or cytologically documented locally advanced unresectable or metastatic solid tumors. * Confirmed MSI-H/dMMR status by the central laboratory. * Have experienced documented disease progression during or after at least first-line therapy. * Have radiologically measurable disease based on RECIST 1.1. * Adequate organ function. * Have agreed to take effective contraception from the date of signing the informed consent form until 120 days after the last administration. Exclusion Criteria: * Prior use of investigational products or devices within 4 weeks prior to C1D1 (Cycle 1 Day 1, the first dose of study drug). * Presence of active autoimmune disease that have received systematic treatment in the past 2 years; or that is judged to be possibly relapsed or requires planned treatment by investigators. * Active inflammatory bowel disease or that required treatment (e.g. Crohn's disease, ulcerative colitis or chronic diarrhea). * Prior use of systematic corticosteroid (\> 10 mg daily prednisone equivalents) or other immunosuppressive medications within 14 days prior to C1D1. * Prior exposure to tumor immunotherapy, such as checkpoint inhibitors (eg. anti-PD-1, anti-PD-L1, anti-CTLA-4 antibody), checkpoint agonists or cellular therapy. * Known history o…