Regorafenib (REG) versus trifluridine/tipiracil (TAS-102) as salvage-line in patients with metastatic colorectal cancer refractory to standard chemotherapies (REGOTAS): A propensity score analysis from a JSCCR multicenter observational study.

Abstract

3540 Background: It is unclear which drug of REG or TAS-102 should be used earlier for the patients with metastatic colorectal cancer (mCRC) who have access to both drugs. This study investigated the comparison of the efficacy between REG and TAS-102 in patients with refractory to standard chemotherapies. Methods: The clinical data of patients who were treated with REG or TAS-102 among these drugs naive mCRC patients between Jun 2014 and Sep 2015 were retrospectively delivered from 24 institutions of Japanese Society for Cancer of the Colon and Rectum (JSCCR). The primary endpoint was overall survival (OS). Propensity score (PS) was calculated with a logistic regression, in which using baseline parameters were included. Two methods, adjusted and matched analysis, to take propensity score were used. The clinical outcomes were evaluated with Kaplan-Meier method and Cox models based on PS adjustment and matching. Results: Total of 589 patients were enrolled and 550 patients (223 patients in the REG group and 327 patients in the TAS-102 group) met criteria for inclusion in the analysis. The results from PS adjusted analyses showed that OS was similar between the two groups (HR of TAS-102 to REG, 0.96; 95% confidence interval, 0.78–1.18). There were also no statistically significant differences between two groups for progression-free survival (HR 0.94) and time to ECOG Performance status≥2 (HR 1.00), expect for time to treatment failure (HR 0.81; P = 0.025). In the subgroup analysis, REG showed favorable survival compared with TAS-102 in the age of < 65 years patients and unfavorable survival in ≥65 years patients (P for interaction = 0.012). In the PS matched sample (174 patients in each group), the clinical outcomes were similar to the results of the PS adjusted analysis. Conclusions: Although REG and TAS-102 showed a similar efficacy in mCRC patients with refractory to standard chemotherapies, the choice of the drug by age might affect the survival. Supported by JSCCR. Clinical trial information: UMIN000020416