Efficacy and safety of camrelizumab plus apatinib compared to apatinib monotherapy as third‐line or above therapy for metastatic colorectal cancer patients: A retrospective cohort study

Abstract

What Is Known and Objective Programmed cell death protein‐1 (PD‐1) inhibitors synergize apatinib for anti‐tumour effect by regulating tumour microenvironment, vascular endothelial growth factor, hypoxia condition, immune response, etc. This study aimed to investigate the treatment efficacy and safety of camrelizumab (PD‐1 inhibitor) plus apatinib as third‐line or above therapy in metastatic colorectal cancer (mCRC) patients. Methods Totally, 64 unresectable mCRC patients receiving camrelizumab plus apatinib (N = 31) and apatinib (N = 33) were retrospectively enrolled. Results Disease control rate (80.6% vs. 57.6%) (P = 0.047) was elevated in camrelizumab plus apatinib group compared to apatinib group; however, objective response rate (22.6% vs. 6.1%) (P = 0.078) only showed an increasing trend but did not achieve statistical significance. Besides, the median (95% confidence interval [CI]) progressive‐free survival (PFS) and overall survival (OS) were 6.9 (3.7–10.1) and 11.5 (7.7–15.3) months in camrelizumab plus apatinib group; meanwhile, the median (95% CI) PFS and OS were 3.6 (1.7–5.5) and 6.7 (5.0–8.4) months in the apatinib group. Additionally, PFS (P = 0.017) and OS (P = 0.006) were prolonged in camrelizumab plus apatinib group compared with apatinib group, which was confirmed by further multivariate Cox's proportional hazards regression analysis (hazard ratio [HR] = 0.340, P < 0.001 for PFS; HR = 0.271, P < 0.001 for OS). The incidence of total, grade 1–2, and grade 3–4 adverse events did not differ between groups (all P > 0.05). Conclusion Camrelizumab (PD‐1 inhibitor) plus apatinib achieves a better treatment efficacy than apatinib as third‐line or above therapy with a good safety profile in mCRC patients.