Clinical Study of Second-Line Standard Therapy Combined With Ongericimab and Toripalimab in Patients With MSS/pMMR Colorectal Cancer Following First-Line Treatment Failure
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.
• Subjects aged 18-75 years (inclusive of 18 and 75 years) at the time of signing the informed consent, regardless of gender.
• Histologically confirmed MSS/pMMR colorectal or rectal cancer, who have progressed on first-line fluoropyrimidine - based combination therapy (including progression during maintenance therapy). If FOLFOXIRI was received in the first - line, screening is not allowed; if progression occurred during neoadjuvant/adjuvant therapy or within 6 months after the last dose, it is considered first-line treatment failure, and the patient is eligible for enrollment.
• Eastern Cooperative Oncology Group (ECOG) performance status score of 0 or 1.
• Predicted survival ≥ 12 weeks.
• At least 1 measurable lesion according to RECIST 1.1 evaluation criteria.
• Adequate organ function；
• Female or male subjects with childbearing potential must agree to have no childbearing plans within 6 months after the end of the last dose during the study period and be willing to take highly effective contraceptive measures together with their partners. For female subjects with childbearing potential, the serum pregnancy test must be negative within 7 days before the first dose, and they must be non - lactating.
• Be able to provide a signed informed consent form, including complying with the requirements and restrictions listed in the Informed Consent Form (ICF) and this protocol.