A phase 1b study of VEGFR inhibitor fruquintinib in patients with pretreated advanced colorectal cancer.

3548 Background: Fruquintinib is a novel oral small molecule compound selectively inhibits vascular endothelial growth factor receptors (VEGFR) 1, 2, and 3 with potent inhibitory effects on multiple human tumor xenografts. In the first-in-human phase I study, fruquintinib demonstrated good tolerability and impressive antitumor activity (ORR=38.2% and DCR=82.4%) in patients (pts) with various heavily pre-treated solid tumors including colorectal cancer (CRC) (ASCO 2012 Abs#3038). Methods: This phase Ib study was designed to evaluate the safety, pharmacokinetics , and efficacy of two fruquintinib regimens: 4mg once daily continuously (QD) or 5mg once daily for three weeks followed with one week break (3/1 wk), as treatment for pts with advanced CRC who had failed at least two prior systemic therapies. The study consists of two stages: a two-arm 1:1 randomization stage including both QD and 3/1 wk regimens, and an expansion stage with the selected regimen. Tumor response was assessed per RECIST1.1. Results: ...