Efficacy And Safety Of Regorafenib As Third-Line Therapy In Metastatic Colorectal Cancer: An Indirect Meta-Analysis

119 Background: The evidence base for optimum third-line therapy for metastatic colorectal cancer (mCRC) is not conclusive. Recent studies have demonstrated the efficacy of regorafenib as third-line therapy in mCRC. This indirect meta-analysis compared the efficacy and safety of regorafenib in comparison to other available third-line therapies in mCRC. Methods: Literature search for randomized controlled trials was conducted in PubMed, Embase and Cochrane library for studies evaluating the efficacy and safety of fruquintinib, regorafenib, TAS-102 and nintedanib as third-line therapies in mCRC patients. The primary outcomes included overall survival (OS), progression-free survival (PFS) and objective response rate (ORR) and safety as the secondary outcome. Hazard ratio (HR) and relative risk (RR) with their respective 95% confidence interval (CI) were used for analysis of survival, clinical response and safety data, respectively. An adjusted indirect meta-analysis with placebo as the common comparator was performed. Results: We identified 8 RCTs studies comparing regorafenib (2 studies), fruquintinib (2 studies), TAS-102 (3 studies) and nintedanib (1 study) against placebo. The OS with regorafenib was significantly better when compared to nintedanib (HR= 0.66, 95% CI 0.45, 0.95, p=0.02), but was similar to that of fruquintinib (HR=1.01, 95% CI 0.67, 1.52, p=0.94) and TAS-102 (HR= 0.97, 95% CI 0.68, 1.38, p=0.88). The PFS and ORR for regorafenib were slightly better than TAS-102 (PFS: HR= 0.86, 95% CI 0.54, 1.37, p=0.5; ORR: RR= 1.13, 95% CI 0.11, 11.05, p=0.92) and nintedanib (PFS: HR= 0.68, 95% CI 0.42, 1.10, p=0.12, ORR: not reported) but was lower than fruquintinib (PFS: HR= 1.53, 95% CI 0.93, 2.52, p=0.08; ORR: RR= 0.68269, 95% CI 0.045, 10.32, p=0.79). Safety analysis showed that the relative risk of adverse events was lesser in patients treated with regorafenib in comparison to fruquintinib but was similar to that of nintedanib and TAS-102. Conclusions: Regorafenib with its efficacy and safety coupled with comprehensive continuously anti-angiogenic therapy, might be the first option in third-line mCRC. Head-on comparisons are required for further validation.