Phase II trial evaluating the long-term efficacy and peripheral sensory neuropathy of adjuvant XELOX in Japanese patients

Abstract Adjuvant oxaliplatin plus capecitabine (XELOX) therapy is recommended for patients with curatively resected colon cancer. However, prospective data on its practical application in Japanese patients are limited. Therefore, this study aims to conduct a long-term clinical evaluation of the efficacy and safety of adjuvant XELOX in patients with curatively resected stage III colon cancer (MCSCO-1024). This prospective, multicenter, open-label, single-arm phase II study enrolled patients with curatively resected stage III colon cancer. The treatment protocol comprised a 120-minute intravenous infusion of oxaliplatin (130 mg/m²) on day 1 and two divided doses of oral capecitabine (2000 mg/m²/day) for 14 days in a 3-week cycle, totaling eight cycles (24 weeks). The primary endpoint was 3-year disease-free survival (DFS), and the secondary endpoints were 5-year overall survival and long-term prognosis of peripheral sensory neuropathy. In total, 196 patients were enrolled between November 2011 and August 2014 (34 months). The 3-year DFS rate was 73%, and the 5-year overall survival rate was 87%. The overall incidence of peripheral sensory neuropathy was 17%, with a 1% rate of grade 3 neuropathy after 5 years. Adjuvant XELOX demonstrated utility and safety in the clinical management of Japanese patients with stage III colon cancer.