Real-world efficacy and toxicity of ipilimumab and nivolumab as a first-line treatment for advanced renal cell carcinoma according to IMDC risk criteria-A multi-center retrospective analysis on behalf of the GUARDIANS group.

Ipilimumab and nivolumab are recommended as first-line therapy for patients with metastatic or advanced renal cell carcinoma (aRCC) and International Metastatic RCC Database Consortium (IMDC) intermediate or poor risk. We retrospectively evaluated efficacy and safety in a multi-center real-world cohort with 356 patients initiating ipilimumab and nivolumab from 17 centers in Germany and Switzerland. Median age was 64 years, most patients were male (69.1%) and had clear cell histology (74.1%). IMDC risk was intermediate in 61.8% and poor in 28.7%. About 37.1% of cases did not meet the inclusion criteria for the CheckMate 214 pivotal study (e.g., poor Eastern Cooperative Oncology Group [Performance Status Scale] [ECOG] status, comorbidities, brain metastases, and impaired renal function). After a median follow-up of 17.5 months, complete response was seen in 8.7%, partial response in 28.7% of patients. Median progression-free survival (PFS) was 8 (95% confidence interval [CI] 5.4-10.6) and median overall survival (OS) 39 months (95% CI 27.5-50.5). Subgroup analysis of patients with non-clear cell histology showed a shorter PFS and OS. Other negative predictors were poor ECOG, fewer induction cycles, ineligibility to pivotal study, and hepatic metastases. Adverse events occurred in 76.4% of patients (35.4% ≥ grade 3). High-dose corticosteroids were applied in 27.3% of cases. Cabozantinib was most frequently administered (63.4%) as subsequent therapy and showed superior OS and PFS compared to other second-line options. Our data support ipilimumab and nivolumab as a first-line treatment of aRCC with robust efficacy and safety. Patient selection was less restrictive in our clinical practice and may explain differences to CheckMate 214 trial.