Systemic therapy for advanced clear cell renal cell carcinoma (ccRCC) after progression on immune-oncology plus VEGF targeted therapy combinations (IO-VEGF).

Abstract

4576 Background: IO-VEGF combinations are the backbone for current and future therapeutic developments in RCC with several IO-VEGF regimens reporting positive results in phase 3 trials. However, limited data exists on outcomes to subsequent therapy in patients progressing on IO-VEGF regimens. Methods: A retrospective analysis was performed on patients with ccRCC at the Memorial Sloan Kettering Cancer Center and Cleveland Clinic Cancer Institute who initiated systemic therapy post IO-VEGF regimens including combinations with VEGFR tyrosine kinase inhibitors (IO-TKI) and combinations with anti-VEGF monoclonal antibodies (IO-mAB). Patients treated on unreported clinical trials were excluded from the outcomes analysis. The primary objective was to evaluate the overall survival (OS) post IO-VEGF. The secondary objectives included objective response rate (ORR) and progression-free survival (PFS) according to RECIST v1.1. Kaplan-Meier methods and the log-rank test were used to evaluate time from start of systemic therapy post IO-VEGF to the event of interest. Results: Fifty-nine patients were treated after discontinuation of IO-VEGF regimens. Prior IO-VEGF regimens included IO-mAB (n = 35, 59%) and IO-TKI (n = 24, 41%). IMDC scores at the start of next line of therapy were favorable in 20%, intermediate in 60% and poor in 20%. Next line of therapy included VEGFR-TKI monotherapy (n = 45, 76%), VEGFR-TKI based combinations (n = 6, 10%), mTOR inhibitors (n = 3, 5%), and unreported clinical trials (n = 5, 9%). VEGFR-TKI containing regimens (n = 51) included cabozantinib (n = 22), axitinib (n = 17), lenvatinib/everolimus (n = 4), pazopanib (n = 4), and others (n = 4). Median OS was 24.5 months (95% CI 12-NE) with a 12 months OS rate of 63%. The ORR was 27% (14/51) and the median PFS was 6.8 months (95% CI 4.8-11). No difference in post IO-VEGF OS was observed when comparing IO- TKI vs IO-mAB (log rank p = 0.7). Conclusions: Post combination IO-VEGF treatment, most patients received VEGFR-TKIs. In this setting, VEGFR-TKIs continue to show clinical activity similar to historic experiences of patients post VEGF monotherapy.