TAS-102 versus placebo (PBO) in patients (pts) ≥65 years (y) with metastatic colorectal cancer (mCRC): An age-based analysis of the recourse trial.

Abstract

638 Background: TAS-102 is comprised of an antineoplastic thymidine-based nucleoside analog, trifluridine, and the thymidine phosphorylase inhibitor, tipiracil hydrochloride, at a molar ratio of 1:0.5 (weight ratio, 1:0.471). Efficacy and safety of TAS-102 in pts with mCRC refractory to standard therapies were evaluated in the RECOURSE trial; enrollment criteria included ≥2 prior lines of standard chemotherapy. Primary results of RECOURSE demonstrated a significant improvement in overall survival (OS) (TAS-102 7.1 mo vs PBO 5.3 mo; HR=0.68; P<0.0001) and progression-free survival (PFS) (HR=0.48; P<0.0001). Methods: This prespecified analysis compared the efficacy and safety of TAS-102 vs PBO in pts ≥65 y and <65 y with mCRC. A retrospective analysis of pts ≥75 y was also performed. Results: Of 800 randomized pts, 352 (44.0%) were ≥65 y and 60 (7.5%) were ≥75 y. Median OS in pts ≥65 y was 7.0 mo with TAS-102 vs 4.6 mo with PBO (HR=0.62, 95% CI: 0.48-0.80, P=0.0002). PFS HR was 0.41 (95% CI: 0.32-0.52, P<0.0001) for pts ≥65 y, also favoring TAS-102. In pts ≥65 y, disease control rate (complete or partial response or stable disease) was 48.7% with TAS-102 vs 15.5% with PBO. An age-related difference in overall incidence of adverse events (AEs) was not observed in either treatment arm. Treatment-related AEs, ≥ Grade 3 AEs, and severe AEs were generally more common in pts ≥65 y than in pts <65 y (Table). Mean drug exposure was similar among pts ≥65 y and ≥75 y, as was overall safety profile. Conclusions: Significant improvements in OS and PFS were observed in pts ≥65 y who received TAS-102 vs PBO, with a mild increase in toxicity. Pts ≥65 y and <65 y showed a generally favorable safety profile. A significant increase in toxicity in pts ≥75 y was not apparent vs the overall ≥65 y population. Clinical trial information: NCT01607957. [Table: see text]