A Study of AK112 With or Without AK117 in Metastatic Colorectal Cancer

Inclusion Criteria: * Histologically proven diagnosis of colorectal adenocarcinoma * Part1: Subjects who have not previously received any systemic antitumor therapy and who have previously received neoadjuvant or adjuvant therapy, the first detection of recurrence or metastasis should be ≥12 months after the last administration of neoadjuvant or adjuvant therapy * Part2: Subjects who have previously received systemic therapy including fluorouracil, oxaliplatin, irinotecan, bevacizumab or anti-EGFR antibodies or could not tolerate or have contraindications to standard treatment * Eastern Cooperative Oncology Group performance status of 0 or 1 * Measurable disease as defined by RECIST v1.1 * Adequate hematologic and organ function Exclusion Criteria: * Known MSI-H(Microsatellite-Instability-High) or dMMR(Mismatch Repair-Deficient) * Prior treatment with immunotherapy, including immune checkpoint inhibitors , immune checkpoint agonists, immune cell therapy and any treatment targeting tumor immune pathway * History of autoimmune disease * Prior allogeneic stem cell or solid organ transplantation * Positive test for human immunodeficiency virus,Active hepatitis B or hepatitis C * Receipt of a live, attenuated vaccine within 30 days prior to randomization, during treatment * Pregnancy or lactation * Dysphagia