Prevalence, disease-free (DFS) and overall (OS) survival of contemporary high-risk renal cell carcinoma (RCC) patients eligible for adjuvant checkpoint inhibitor trials: A RECUR database analysis

636 Background: Designing adjuvant trials is challenging because of uncertainties of prevalence and outcome of high-risk RCC despite use of validated risk scores. Methods: RECUR is a European multicenter database capturing patient and tumour characteristics, recurrence patterns and survival of all patients treated with (partial) nephrectomy for non-metastatic RCC from 2006 to 2011 at each participating center. We evaluated prevalence, DFS and OS of RCC according to eligibility criteria of adjuvant trials IMMotion 010 (NCT03024996, IM), Checkmate 914 (NCT03138512, CM), Keynote-564 (NCT03142334, KN) and RAMPART (NCT03288532, RP), which all predominantly recruited high-risk clear cell RCC patients. Results: Of 2669 relevant patients in RECUR, 424(15.9%), 681(25.5%), 579(21.7%) and 1221(45.7%) met eligibility criteria for IM, CM, KN and RP respectively (p < 0.001). Median DFS and OS estimates (Kaplan-Meier) in RECUR corresponding to each trial placebo arm were 37.5 (95%CI 30.4–44.6) and 89.6 (95%CI 76.1–103.0) months for IM, 89.4 (95%CI 66.1–112.7) and 96.2 (95%CI 79.8–112.6) months for CM, 62.6 (95% CI39.6–85.6) and 86.6 (95%CI 74.3–98.9) months for KN and finally at 144 months (DFS not reached) and 123.8 (95% CI 110.1 – 137.4) months for RP. Additionally, at pairwise analysis of evaluated trials, DFS estimates were significantly different between all trials (p < 0.001) except between CM and KN (p = 0.125), while OS estimates did not differ significantly between all trials except between RP and the other three trials (p = 0.002). Conclusions: Percentages of eligible high-risk RCC patients in RECUR were low to moderate and, together with estimated placebo arm DFS and OS, varied due to differences in trial eligibility criteria. These differences may impact on the results and interpretation of the trials.