Rationale and Study Protocol of the J-SAVER Study: A Phase II Study of S-1 on Alternate Days Combined with Bevacizumab in Patients Aged ≥75 Years with Metastatic Colorectal Cancer

Abstract

Fluoropyrimidine combined with bevacizumab is commonly used in elderly patients with metastatic colorectal cancer worldwide. However, the propor tion of elderly patients who discontinued treatment due to toxicities was higher than that of younger patients. The aim of this study is to develop a less toxic sche dule of S-1, while maintaining the anti-tumor effect. This phase II study is aimed to evaluate an alternate-day administration of S-1 combined with bevacizumab in untreated elderly patients (aged ≥75 years) with metastatic colorectal can cer. The primary endpoint is progression-free survival, and the secondary end points are safety, response rate, and overall survival. The expected median pro gression-free survival is 8.5 months, and the minimum efficacy threshold is 5.0 months. The total required sample size is calculated as 50 patients, with a 2-sided type I error of 0.10 and a power of more than 80%. This study is ongoing, and fifty-four patients were enrolled until October 2016. We hope that S-1 on alternate days combined with bevacizumab for elderly patients with colorectal cancer is well tolerated and can maintain effectiveness. Trial registration: UMIN clinical trials UMIN000010402.