First-line trifluridine/tipiracil plus bevacizumab for unresectable metastatic colorectal cancer: SOLSTICE study design

Trifluridine/tipiracil (TT) is an orally administered combination of the thymidine-based nucleoside analogue trifluridine and the thymidine phosphorylase inhibitor tipiracil hydrochloride, which increases the bioavailability of cytotoxic trifluridine. Encouraging antitumor activity of first-line TT + bevacizumab (TT-B) has been observed in a Phase II study in patients with unresectable metastatic colorectal cancer ineligible for combination oxaliplatin- or irinotecan-based therapy. Here, we describe the design of SOLSTICE (NCT03869892), an open-label, Phase III trial in unresectable metastatic colorectal cancer patients who are not candidates for, or do not require, intensive therapy. The 854 patients will be randomized 1:1 to receive first-line TT-B versus capecitabine + bevacizumab. The primary objective is to demonstrate superior progression-free survival with TT-B over capecitabine + bevacizumab. The first patient was enrolled in March 2019.