A Systematic Review and Network Meta-Analysis of Regorafenib and TAS-102 in Refractory Metastatic Colorectal Cancer

Background Regorafenib at different dosing strategies and TAS-102 are treatment options for refractory metastatic colorectal cancer (mCRC). We aimed to evaluate the comparative effectiveness evidence supporting these different strategies. Materials and Methods We searched different databases for randomized controlled trials evaluating TAS-102 or regorafenib in patients with refractory mCRC who failed prior oxaliplatin, irinotecan, and fluoropyrimidine. Outcomes of interest included overall survival (OS) and progression-free survival (PFS). The overall effect was pooled using the DerSimonian random effects model. We conducted network meta-analysis based on White's multivariate meta-regression to pool evidence from direct and indirect comparisons. Results Six trials at low risk of bias (2,445 patients) were included. Direct comparisons showed that Rego 160 and TAS-102 as monotherapy were superior to best-supportive care (BSC) in terms of PFS (Rego 160: hazard ratio [HR], 0.4; 95% confidence ratio [CI], 0.26-0.63; TAS-102: HR, 0.46 CI, 0.40-0.52) and OS (Rego 160: HR, 0.67; CI, 0.48-0.93; TAS-102: HR, 0.67; CI, 0.57-0.80). Network analysis showed no statistically difference in PFS or OS between Rego 160 and TAS-102. Rego 80+ was superior to BSC in terms of OS (HR, 0.44; CI, 0.23-0.84) and PFS (HR, 0.37; CI, 0.21-0.66). Rego 80+ was associated with statistically nonsignificant improvement in OS and PFS compared with TAS-102 and Rego 160. Conclusion Regorafenib 160 and TAS-102 appear to have similar efficacy. Rego 80+ is shown to be superior to BSC. A trend for improved OS was observed with Rego 80+ versus Rego 160 or TAS 102. Implications for Practice Regorafenib at a dose of 160 mg and TAS-102 appear to have similar efficacy in patients with refractory metastatic colorectal cancer. Regorafenib with a dose escalation strategy is superior to best-supportive care. Given its tolerability and the observed trend in survival benefit compared with regorafenib 160, dose escalation strategy of regorafenib (80+) may be the preferred option in this setting.