293 Background: Checkpoint inhibitors (CPIs) are a treatment option for patients with metastatic renal cell carcinoma (mRCC), but there is limited clinical data on the efficacy of targeted therapies following CPI treatment. Cabozantinib is a tyrosine kinase inhibitor (TKI) that targets multiple receptor kinases implicated in tumorigenesis. In the US, cabozantinib is approved for use in patients with advanced RCC including after CPI treatment. Methods: This retrospective observational cohort study (NCT04353765) evaluated outcomes associated with cabozantinib or other TKIs (axitinib, lenvatinib, pazopanib, sorafenib, sunitinib) in patients with mRCC following CPI treatment. Eligible patients initiated TKI therapy between May 1, 2016 and Sep 31, 2019 and had received a CPI as their last systemic treatment prior to TKI therapy. Patients were identified from the US Oncology Network iKnowMed electronic health record database through structured queries and a targeted chart review. The following real-world outcomes were assessed: 6-month response rate (RR6months; primary); overall response rate (ORR); overall survival (OS); time to treatment discontinuation (TTD); rates of dose reductions, and discontinuation due to adverse events (AEs). The p value for RR6months was used to test for non-inferiority. Results: Eligible patients ( n = 247) had a mean (SD) age of 65.9 (10.5) years and 74.1% were male; 75.7% ( n = 187) received cabozantinib and 24.3% ( n = 60) received other TKIs. All patients had intermediate or poor MSKCC score; more poor-risk patients received cabozantinib than other TKIs (28.9% vs 20%). Outcomes data are shown in the Table. Compared with other TKIs, cabozantinib was associated with a significantly higher RR6months and ORR, and TTD was twice as long with cabozantinib. Discontinuation due to AEs was more frequent with other TKIs than with cabozantinib, although this was not statistically significant; 21.7% of discontinuations occurred during the first 3 months of treatment. AEs leading to discontinuation were consistent with the known safety profile of the products. Conclusions: In this mRCC population receiving routine care in the US, cabozantinib was used more frequently than other TKIs after CPI treatment. Cabozantinib was an effective and well tolerated option post-CPI, with a high response rate in the real-world setting.abozantinib was associated with a significantly higher response rate and a lower discontinuation rate due to AEs; TTD was double that of other TKIs. [Table: see text]
Cabozantinib as Advanced Treatment Line for Metastatic Renal Cell Carcinoma: Real World Outcomes and Associated Factors