Outcomes After First-Line Therapy For Immune/Immune Or Immune/Vegf Combinations

706 Background: The introduction of first line immune combination or immune/VEGF therapy in metastatic renal cancer has changed treatment landscape. Here we compare outcomes of these combinations with patients treated with first line sunitinib. The focus is on the impact of subsequent treatments. Methods: This retrospective analysis was performed at Barts Cancer Institute for consecutive patients from April 2015 when front line immune therapy was first used at our institution. Only patients enrolled on reported prospective trials were included to avoid selection bias. Patients were treated with VEGF targeted therapy (n=35) (group V), PD-1 + CTLA4 (n=15) (group I/I) or a combination of PD-L1 + VEGF TKI inhibitor (n=29) (group I/V). The primary analysis focused on the proportion of patients who received second line therapy and their outcome. Results: 79 patients received first line therapy for clear cell RCC. IMDC good, intermediate and poor risk occurred in 27.8%, 60.8% and 11.4% respectively. Front line response rates for V, I/I and I/V groups were 34.3%, 46.7% and 65.5% and PFS in V, I/I and I/V groups were 11mo (95%CI 6-16), 18mo (95% CI 0-41) and 36mo (95% CI 13-59), respectively (P= 0.016). OS in the 3 groups were immature but not significantly different. Second line therapy occurred in 87.5%, 92.9% and 81.8% in the V, I/I and I/V groups respectively (in those who progressed after initial therapy). Second line response rate post first line V, I/I and I/V were 11%, 0% and 0% respectively as per RECIST 1.1. 63% of patients receiving VEGF front line therapy subsequently received immune therapy. 95% of patients receiving first line immune/immune or immune/VEGF combination therapy received VEGF therapy in the second line. Only 70% of patients who progressed on second line therapy got 3rd line therapy across all arms. Conclusions: Response rates after front line immune combination therapy are modest. The sequencing of PD-1 therapy after VEGF monotherapy appears particularly relevant in outcomes. A high proportion of patients are sequencing therapy and reaching third line which may help improve outcomes.