The Efficacy and Safety of IBI351, Cetuximab β Combined With FOLFIRI as First-line /IBI351, Cetuximab β as Second-line in the Treatment of KRAS G12C-mutated Metastatic Colorectal Cancer

This is an open-label, multicenter, single-arm Phase II clinical study, divided into subgroups A and B: Cohort A - To evaluate the efficacy and safety of IBI351, cetuximab β combined with FOLFIRI as first-line treatment for metastatic colorectal cancer with KRAS G12C mutations; Twenty untreated patients with advanced colorectal cancer with KRAS G12C mutation are proposed to be enrolled and treated with the first-line IBI351+ cetuximab β injection +FOLFIRI regimen. The historical reference is expected to be around 40-50%, and it is expected to increase to around 75%. Therefore, among the 20 patients, if ≥15 patients achieve remission, it is considered that the efficacy of the trial protocol is statistically significant. Cohort B - To evaluate the efficacy and safety of BI351 and cetuximab β as second-line treatment for metastatic colorectal cancer with KRAS G12C mutations. It is proposed to enrolled 30 patients with advanced colorectal cancer with KRAS G12C mutation who have progressed after first-line treatment, and evaluate IBI351+ cetuximab β injection for second-line treatment. The historical reference is around 25%, and it is expected to increase to around 50%. Therefore, among the 30 patients, if ≥15 patients achieve remission, it is considered that the efficacy of the trial protocol is statistically significant. Imaging assessment of tumor remission was conducted every 8 weeks until disease progression. The period from the start of treatment to disease progression is defined as PFS. The safety observation indicators include: the incidence and severity of adverse events (AE) and serious adverse events (SAE); Laboratory tests, vital signs, physical examinations, and changes in electrocardiogram (ECG). Record the subsequent tumor treatment and survival follow-up after the progression. Definition of study conclusion: The study will conclude after the last subject has been treated for 2 years or has completed the treatment (whichever occurs first).