NCI9673 part B: randomised phase 2 study of nivolumab with or without ipilimumab in refractory metastatic anal cancer

Randomised phase 2 part of the ETCTN trial NCI9673: patients with refractory metastatic squamous cell carcinoma of the anal canal were randomised to nivolumab alone or nivolumab with ipilimumab.

Median progression-free survival was 2.9 months with nivolumab and 3.7 months with the combination (hazard ratio 0.86, p 0.25); response rates were 17.4 and 21.5 percent and median overall survival 15.9 and 20.0 months (hazard ratio 0.98). Grade 3 or worse treatment-related adverse events occurred in 12 percent with nivolumab and 25 percent with the combination. Circulating TIGIT-positive CD8 T cells rose with dual blockade.