Nivolumab in metastatic nonclear cell renal cell carcinoma: First results of the AcSe prospective study.

Abstract

699 Background: AcSe Nivolumab (N), is a non-randomised, open-label, multicentric study to investigate the efficacy and safety of nivolumab monotherapy in patients (pts) with specific rare cancers (NCT03012581). We report on the non-clear cell renal cell carcinoma (RCC) cohort. Methods: Primary endpoint was objective response rate (ORR) at 12 weeks according to RECIST1.1. All pts receives N at 240mg IV every 2 weeks. Secondary endpoints included progression free survival (PFS), overall survival (OS), best response, and safety. Results: Between 07/2017 and 02/2019, 50 pts have been enrolled across 13 institutions. Median age was 61.4 years old, 70% were male. ECOG PS was 0, 1, 2, in 29%, 63% and 8% of pts respectively. Histological types were papillary (pRCC) type 2 (41%), chromophobe (18%), pRCC type I (10%), pRCC unclassified (8%), collecting duct carcinoma (CDC) (8%), and others (including predominant sarcomatoid, renal medullary carcinoma, MITF associated RCC, unclassified RCC). N was used in first line in 16%, second line in 54% and third line or beyond in 30%. IMDC risk group was 14%, 70% and 16% for good, intermediate and poor risk respectively. With a median follow up of 10.4 months (mo), 42 pts had discontinued N. The 12 weeks-ORR was 6% (3 PR), with stable disease in 49% and PD in 44% of pts. The best ORR was 10%. Median PFS was 3.9 mo (IC95% [2.9; 8.3]). At time of analysis, 25 pts (50%) had died and 12-months OS rate was 47.7% (IC95% [33.5; 67.8]). Overall, 31 pts (62%) have presented at least one grade ≥ 3 AE. No new safety signal with N was reported. 12 weeks-ORR and best ORR according to distinct histology are presented in table 1. Pts with PR were 1pRCC type 2, 1pRCC type 1, 1 CDC, 1 MITF RCC and 1 unclassified. Conclusions: We report the first prospective study of N single agent in non-clear cell RCC. N demonstrates limited activity in a pretreated and heterogeneous non- clear cell RCC population. Interestingly 1/4 CDC developed PR while no response was noted in chromophobe RCC. Clinical trial information: NCT03012581. [Table: see text]