Phase II study of FOLFOX plus regorafenib (REGO) in patients with unresectable or metastatic esophagogastric (EG) cancer.

4053 Background: REGO is a VEGFR2, FGFR2 and PDGFR small-molecule inhibitor with survival benefit in metastatic colorectal cancer. We performed a phase II trial of first-line FOLFOX+REGO in metastatic EG cancer. Methods: Patients (pts) with previously untreated metastatic EG adenocarcinoma with measurable or evaluable disease received mFOLFOX6 q14d and oral REGO 160 mg daily on days 4 to10 and 18 to 24 q28d. The primary objective was to improve historical 6-month progression-free survival (PFS) from 40% to 61% with REGO. With target accrual of 36 pts and 5% type I error rate, FOLFOX+REGO would be considered promising if ≥ 20 pts are progression free at 6 months. Tumor biomarker analysis was performed on samples using an on-site next generation sequencing (NGS) assay. Secondary endpoints included safety, partial response (PR) rate, disease control rate (DCR, PR+stable disease), exploratory biomarker analysis and overall survival. Results: Between 8/2013 -11/2014, 36 pts (10 esophageal/16 gastric/10GEJ) wer...