Salvage Ipilimumab and Nivolumab in Patients With Metastatic Renal Cell Carcinoma After Prior Immune Checkpoint Inhibitors.

PURPOSE Immune checkpoint inhibitors (ICIs) are standard therapy in metastatic renal cell carcinoma (RCC). The safety and activity of the combination of ipilimumab and nivolumab in patients who have received prior ICI targeting the programmed death 1 (PD-1) pathway remains unknown. We evaluated ipilimumab and nivolumab in patients with metastatic RCC after prior treatment with anti-PD-1 pathway-targeted therapy. PATIENTS AND METHODS Patients with metastatic RCC who received prior anti-PD-1 pathway-targeted therapy and subsequently received ipilimumab and nivolumab were reviewed. Objective response rate and progression-free survival per investigator assessment were recorded. Toxicity of ipilimumab and nivolumab was also assessed. RESULTS Forty-five patients with metastatic RCC were included. All patients (100%) received prior ICIs targeting the PD-1 pathway. The median age was 62 years (range, 21-82 years). At a median follow-up of 12 months, the objective response rate to ipilimumab and nivolumab was 20%. The median progression-free survival while on ipilimumab and nivolumab was 4 months (range, 0.8-19 months). Immune-related adverse events (irAEs) of any grade with ipilimumab and nivolumab were recorded in 29 (64%) of the 45 patients; grade 3 irAEs were recorded in 6 (13%) of the 45 patients. CONCLUSION Ipilimumab and nivolumab demonstrated antitumor activity with acceptable toxicity in patients with metastatic RCC who had prior treatment with checkpoint inhibition.