Abstract
BACKGROUND: A previous Phase I/II study demonstrated that TAS-102 (trifluridine/tipiracil [FTD/TPI]) plus bevacizumab (Bev) has encouraging efficacy and controllable safety for patients with previously treated metastatic colorectal cancer. Therefore, we designed for assessing the efficacy and safety of FTD/TPI plus Bev in elderly patients with previously untreated metastatic colorectal cancer. METHODS: This is a multicenter, single-arm Phase II study included patients ≥70 years old with previously untreated, unresectable metastatic colorectal cancer. Treatment consisted of FTD/TPI plus Bev given every 4 weeks. The primary endpoint was progression-free survival (PFS), assuming a null hypothesis of a PFS of 5 months. The secondary endpoints were the overall survival (OS), overall response rate (ORR), and adverse events (AEs). RESULTS: Between 5 January 2017 and 13 March 2018, 39 patients were enrolled from 18 institutions. The median patient age was 76.0 years (range, 70-88); the ECOG-PS was 0 in 24 patients and 1 in 15 patients. The median PFS was 9.4 months as a primary endpoint, and the median OS was 22.4 months. The ORR was 40.5% and the disease control rate was 86.5%. Grade 3-4 AEs included neutropenia (71.8%), leukopenia (51.3%), anorexia (15.4%), febrile neutropenia (10.3%), and fatigue (10.3%). CONCLUSIONS: FTD/TPI plus Bev is an effective and well-tolerated regimen for elderly patients with previously untreated metastatic colorectal cancer. Capecitabine/bevacizumab can be selected as a subsequent maintenance therapy without irinotecan and oxaliplatin because FTD/TPI has no cross-resistance with 5-fluorouracil. CLINICAL TRIAL REGISTRATION: UMIN clinical trials registry (UMIN000025241).