Vemurafenib, cetuximab and camrelizumab in BRAF V600E-mutated/MSS metastatic colorectal cancer
摘要
Patients with BRAF V600E-mutated/microsatellite stable (MSS) metastatic colorectal cancer (mCRC) are associated with a poor prognosis. Backline treatment has minimal efficacy. Multi-target inhibitors of the RAS-RAF-MEK signaling pathway combined with PD-1 monoclonal antibody may be a promising strategy for BRAF V600E-mutated mCRC.
MethodsThis prospective phase I trial enrolled patients to explore tolerability and safety of the VCC regimen in previously treated patients with BRAF V600E-mutated/MSS mCRC. Enrolled patients treated with VCC therapy every 2 weeks (cetuximab 500mg/m2; camrelizumab 200 mg; vemurafenib 960 mg orally once daily). Adverse events and efficacy were monitored and recorded throughout the administration and follow-up period.
ResultsThis trial enrolled 12 eligible patients. Total 2 patients had DLT: one had grade 3 thrombocytopenia and immune myocarditis, another had grade 3 vaginal bleeding. Adverse events (AEs) of grade 3 or higher occurred in 50% of patients. Grade 3 AEs were mainly drug-related fever (25.0%), drug-related rash (16.7%). Median overall survival (OS) and PFS were 7.19 months and 3.47 months, respectively. The ORR and DCR were 33.3% and 66.7%. One patient achieved CR. three patients achieved PR. An abnormal CD4/CD8 ratio was associated with a higher risk of progression. Different efficacy of VCC regimen may be attributed to the difference in tumor immune environment.
ConclusionsA combination of vemurafenib, cetuximab combined with camrelizumab exhibited manageable adverse reactions and efficacy in BRAF V600E-mutated/MSS patients with metastatic colorectal cancer who progressed after standard treatment. This is a pilot study and a larger phase II trials is planned to validate the findings. (ClinicalTrials.gov ID: NCT05019534).