O-12 NCI9673 (Part B): A multi-institutional ETCTN randomized phase II study of nivolumab with or without ipilimumab in refractory, metastatic squamous cell carcinoma of the anal canal

The proportion of patients (pts) with squamous cell carcinoma of the anus (SCCA) who develop incurable distant metastases continues to increase. Previously, in the single-arm study, NCI9673 (Part A), the anti-PD-L1 antibody nivolumab (N) demonstrated clinical efficacy for pts with unresectable or metastatic SCCA. In NCI9673 (Part B), we evaluated the role of the anti-CTLA-4 antibody ipilimumab (I) in combination with N for pts with refractory, incurable SCCA.