Combination of Modest Dosage of Bevacizumab with TAS-102 Provided the Comparable Efficacy in Treating Refractory Metastatic Colorectal Cancer

Abstract Background Given that the combination of bevacizumab and TAS-102 is used to treat refractory metastatic colorectal cancer (mCRC), we aimed to evaluate the efficacy of modest doses of bevacizumab in combination with TAS-102 for the treatment of refractory mCRC. Methods In total, 261 patients with refractory mCRC were enrolled and categorized into two groups: TAS-102 combined with bevacizumab and TAS-102 alone. In the bevacizumab combination group, patients were further divided into two subgroups based on a median dose of 3.3 mg/kg. Categorical variables were compared using the chi-squared or Fisher’s exact tests, and continuous variables were assessed using the t-test. The Cox proportional hazards model was used to adjust for covariates. Survival analysis was performed using the log-rank test and Kaplan–Meier curves. Specific survival was evaluated using Restricted Mean Survival Time (RMST) and landmark analysis. Result The median progression-free survival (PFS) was 3.7 months in the TAS-102combined with bevacizumab group, and 2.2 months in the group without bevacizumab, showing statistical significance in favor of bevacizumab combination group (P = 0.004). The median overall survival (OS) was 9.4 months in the bevacizumab combination group and 10.3 months in the group that did not receive combination therapy. A survival benefit was observed within 9.5 months in both the RMST and landmark analyses. However, no long-term OS benefit was evident, regardless of bevacizumab combination (P = 0.248). Conclusion The modest doses of bevacizumab and TAS-102 provided comparable efficacy to the standard dose schedule, especially within a limited timeframe of 9.5 months.