Vascular endothelial growth factor receptor tyrosine kinase inhibitor (VEGFR-TKI) rechallenge for patients with metastatic renal cell carcinoma after treatment failure using both VEGFR-TKI and mTOR inhibitor

Abstract

To assess the efficacy of vascular endothelial growth factor receptor tyrosine kinase inhibitor (VEGFR-TKI) rechallenge for metastatic renal cell carcinoma (mRCC) patients and to identify predictive factors for increased progression-free survival (PFS) or overall survival (OS). The clinicopathological features, outcomes, and prognostic factors of mRCC patients who were treated with VEGFR-TKI after treatment failure using both VEGFR-TKIs and mTOR inhibitors (mTORi) were reviewed. A total of 29 eligible patients were included. Five (17 %) patients achieved partial response (PR) with a median response duration of 9.5 months (95 % CI 5.7-13.4 months), and additional 16 patients (55 %) achieved stable disease. With a median follow-up period of 19.2 months (95 % CI 18.9-19.6 months), the median PFS and OS were 3.0 months (95 % CI 1.1-4.9 months) and 4.9 months (95 % CI 2.9-6.8 months), respectively. In univariate analysis, the best response to first-line VEGFR-TKI (PR vs. non-PR, p < 0.001) and time to rechallenge (TTR, a parts per thousand currency sign12 months vs. between 12 and 24 months vs. > 24 months, p = 0.005) were identified as predictive factors for longer PFS on VEGFR-TKI rechallenge. In addition, an MSKCC risk group (intermediate- vs. poor-risk group, p = 0.027), better response at first-line VEGFR-TKI (PR vs. non-PR, p = 0.003), and TTR (a parts per thousand currency sign12 months vs. between 12 and 24 months vs. > 24 months, p = 0.026) were identified as prognostic factors for longer OS. VEGFR-TKI rechallenge may be a viable option for select metastatic RCC patients who fail both VEGFR-TKI and mTORi therapies.