Primary Renal Tumour Response in Patients Treated with Nivolumab and Ipilimumab for Metastatic Renal Cell Carcinoma: Real-world Data Assessment

Following CARMENA and SURTIME, patients with metastatic renal cell carcinoma (mRCC) and International Metastatic RCC Database Consortium (IMDC) intermediate and poor risk receive systemic therapy with the primary tumour (primary) in place, with the option of deferred cytoreductive nephrectomy (CN) in responding patients. We retrospectively analysed the safety and efficacy of first-line nivolumab/ipilimumab in 71 primary mRCC patients (42.3% IMDC poor risk; 43.6% with more than three metastatic sites). The baseline mean primary diameter was 9.3 cm and median follow-up was 11.5 mo. Of 69 patients with at least one follow-up computed tomography scan, 23 (33.3 %) had a partial response (PR) of the primary after a median of 4.8 mo, which was associated with a 91.3% overall response rate at metastatic sites (MSs) and absence of progressive disease, irrespective of the IMDC risk. The complete response (CR) rate at MSs (n = 7 [10.1%]) is similar to the CR rate in CheckMate 214. Thirteen deferred CNs were performed (18.8%) after a median of 13 mo, rendering four patients disease free. Only 4.3% of primaries progressed; grade 3–4 immune-related adverse events occurred in 31.9%. Irrespective of the IMDC risk, patients with a PR in the primary had a 1-yr overall survival rate of 89% versus 67% in those without (p = 0.012). PATIENT SUMMARY: Patients with metastatic kidney cancer receiving immunotherapy with nivolumab and ipilimumab had superior response at metastatic sites and better survival irrespective of International Metastatic RCC Database Consortium (IMDC) risk.