Rationale and design of the TRUSTY study: a randomised, multicentre, open-label phase II/III study of trifluridine/tipiracil plus bevacizumab versus irinotecan, fluoropyrimidine plus bevacizumab as second-line treatment in patients with metastatic colorectal cancer progressive during or following first-line oxaliplatin-based chemotherapy

BACKGROUND: Trifluridine/tipiracil is an oral agent approved for the treatment of patients with metastatic colorectal cancer (mCRC). Trifluridine is an antineoplastic thymidine analogue, and tipiracil improves its bioavailability. A phase I/II C-TASK FORCE study of trifluridine/tipiracil plus bevacizumab for patients with refractory mCRC demonstrated promising efficacy results with mild toxicity profile. It is important that quality of life be preserved in patients with mCRC without compromising their prognosis. Here, we outline the TRiflUridine/tipiracil in Second-line sTudY phase II/III study (JapicCTI-173618), designed to demonstrate non-inferiority in overall survival of trifluridine/tipiracil plus bevacizumab compared with irinotecan, fluoropyrimidine and bevacizumab combination regimens as second-line treatment in patients with mCRC. PATIENTS AND METHODS: Eligible patients have confirmed unresectable advanced or recurrent colorectal adenocarcinoma and have failed to respond to first-line oxaliplatin-based chemotherapy. A total of 524 patients are to be randomly assigned (1:1 ratio) to trifluridine/tipiracil plus bevacizumab or irinotecan, fluoropyrimidine and bevacizumab and stratified according to RAS status (wild type vs mutant). The primary endpoint of the phase II part is disease control rate with trifluridine/tipiracil plus bevacizumab therapy. Secondary endpoints are response rate and safety with trifluridine/tipiracil plus bevacizumab therapy. In the phase III part, the primary endpoint is overall survival, and secondary endpoints include quality of life, progression-free survival, response rate, disease control rate, safety, time to treatment failure, time to post-study treatment failure and the proportion of patients receiving post-study treatment. The first patient was enrolled in October 2017 and the study is anticipated to be completed in 2022. CLINICAL TRIAL REGISTRATION: JapicCTI-173618 (JapicCTI).