Multicenter phase 2 trial of ipilimumab plus nivolumab for adrenocortical carcinoma

Immunotherapy showed activity in multiple common cancers ; however, less is known about efficacy in rare tumors (incidence less than 6 per 100,000 per year). In the adrenocortical carcinoma cohort of the multicenter phase 2 NCI/SWOG S1609 Dual Anti-CTLA-4 and Anti-PD-1 blockade in Rare Tumors (DART) previously treated patients received ipilimumab 1 mg/kg every 6 weeks plus nivolumab 240 mg every 2 weeks. Among 21 patients, three had confirmed partial response (14%), one had an uncomfirmed partial response, one had stable disease > 6 months for a clinical benefit rate of 21%. The progression-free survival of patients (n=7) with iRECIST clinical benefit was 57, 52, 18, 15, 13, 13, 7, and 7 months. The median overall survival was 15.8 months, with a 6-months OS rate of 76%. Treatment-related adverse events leading to discontinuation of therapy occurred in four patients (21%). There were no grade 5 adverse events. The authors conclude that the combination of ipilimumab and nivolumab showed activity among patients with refractory adrenocortical cancer.