41: Real-world treatment outcomes of first-line axitinib plus pembrolizumab by IMDC risk score for patients with advanced renal cell carcinoma in the United States.

Background: The combination of axitinib plus pembrolizumab (AXI+PEM) is a standard of care in the first-line (1L) treatment of patients with advanced clear cell renal cell carcinoma (ccRCC). We report the real-world outcomes of patients with advanced ccRCC who received 1L AXI+PEM, stratified by International Metastatic RCC Database Consortium (IMDC) risk score.

Methods: Electronic medical record data from the Flatiron Health, nationwide de-identified database (~280 cancer clinics across 800 sites in the US) were used to select patients with confirmed Stage IV/metastatic RCC who initiated 1L AXI+PEM on or after 1/1/2018 to 7/31/2022. The efficacy of 1L AXI+PEM, stratified by IMDC risk score subgroups, was assessed by real-word progression-free survival (rwPFS) and real-world overall survival (rwOS).

Results: 340 patients received 1L AXI+PEM, with mean follow-up of 19.2 (0.1–41.6) months. At diagnosis, 56.5% of patients had Stage IV RCC and 78.2% of patients had clear cell histology. IMDC risk score was favorable, intermediate, poor, poor/intermediate or unknown for 23, 117, 75, 81 and 44 patients, respectively. Median rwPFS was 15.9, 8.2, 5.9 and 8.4 months in the patients with favorable, intermediate, poor, or poor/intermediate risk status, respectively (Table). Median rwOS was not reached (NR) for patients with a favorable IMDC risk score. rwOS in patients with intermediate, poor or poor/intermediate risk scores were 30.5, 12.3, and 24.1 months, respectively (Table). Less than half received subsequent therapy (43.5%); of those, 56.8% received cabozantinib in 2L, and 32.4% received IO-based therapy.

Conclusions: These data describe the impact of IMDC risk score on the outcomes of 1L AXI+PEM in patients with ccRCC, providing further understanding of the clinical outcomes and treatment patterns of patients with ccRCC in the US.