Multicenter phase 2 trial of nivolumab with definitive chemoradiotherapy for esophageal squamous cell carcinoma

A multicenter phase 2 trial at five centers in Japan evaluated the combination of nivolumab with definitive chemoradiotherapy (CRT) for esophageal squamous cell carcinoma (ESCC) in patients aged 20-75 years with an ECOG performance status 0 or 1 and adequate organ and bone marrow function. Patients underwent concurrent CRT with nivolumab, followed by maintenance nivolumab for up to one year. The primary endpoint was safety, which was met with only 2 of 41 patients (5%) expetiencing grade 3 pneumonitis. The most common adverse events were esophagitis, constipation, and lymphopenia, and no treatment-related deaths occurred. The overall complete response rate was 73% (95% CI 58-84). One-year progression-free survival rate was 65.4% (95% CI 48.6-77.9) and the one-year overall survival rate was 92.7% (79.0-97.6). The authors conclude that nivolumab combined with definitive CRT is feasible and showed acceptable toxicity in patients with ESCC.