Standard Second-line Therapy With ONgericimab and TOripalimab in pMMR/MSS Colorectal Cancer: a Single-arm Phase II Trial

The ONTOP study is a prospective, single-arm, open-label phase II clinical trial. A total of 32 patients with advanced MSS/pMMR colorectal cancer who have failed first-line treatment will receive second-line standard treatment combined with Ongericimab and toripalimab. Among them, patients who received irinotecan-containing treatment in the first line will be administered the regimen of Ongericimab + toripalimab + bevacizumab + FOLFOX. Patients who received oxaliplatin-containing treatment in the first line will be administered the regimen of Ongericimab + toripalimab + bevacizumab + FOLFIRI. Treatment will continue until disease progression, initiation of new anti-tumor treatment, active request of the subject, or determination by the investigator that study drug administration needs to be terminated. The primary study endpoint is the objective response rate (ORR), and the secondary study endpoints include duration of response (DoR), disease control rate (DCR), progression-free survival (PFS), overall survival (OS), and safety, etc.