Phase 2 basket trial of ipilimumab plus nivolumab for rare tumors: results in the vulvar cancers cohort of DART SWOG S1609

Dual PD-1/CTLA-4 inhibition shows promise in various malignancies. The multicenter phase 2 basket trial SWOG S1609 DART trial evaluates the combination of nivolumab and ipilimumab in rare tumors. Results of the vulvar cancers cohort have now been published. Sixteen evaluable patients (median age 55.5 years, up to 6 previous lines of treatment) were analyzed. Objective response was seen in 3 patients (ORR 18.8%), one additional patient had stable disease (CBR 25%), and one additional patient had unconfirmed partial respons (CBR plus unconfirmed PR rate 31%). The progression-free survival in these five patients was 34.1, 16.7, 15.5, 7.2, and 7.0 months. The median progression-free survival and overall survival was 2.2 and 7.6 months, respectively. Grade 3 or 4 adverse events occurred in four patients (25%). One patient discontinued treatment due to an adverse event, and one patient had a grade 5 adverse. The authors conclude that ipilimumab plus nivolumab resulted in objective response in three out of 16 vulvar cancer patients.