Background: Nivolumab (N) has been shown active in patients (pts) with mRCC after failure of 1 or 2 TKIs. Efficacy and safety of N in pts with brain metastases (BM) from RCC is still unknown. The aim of this study is to report preliminary data of the Nivoren study in pts with BM. Methods: GETUG-AFU 26 (Nivoren) is a prospective phase 2 study assessing safety and efficacy of N in a broader mRCC patient population than those recruited in the pivotal phase 3, including pts with BM (previously treated or not, but not requiring steroids), with previous mTOR inhibitor, with PS 2 as well as in previously highly pretreated pts. N was given every 2 weeks at 3mg/kg, until disease progression or unacceptable toxicity. Treatment was allowed beyond progression in case of clinical benefit. All pts had brain CT scan or MRI at baseline. Results: Up to December 2016 , 588 pts have been enrolled including 55 pts with BM (35 (67%) ,6 (12%) and 11 (21%) with 1, 2 or > 2 BM, respectively. Of those 55 pts, 10 pts (23%) were PS 2 and 25 (58%) PS 1, and 16 patients (29%) had received more that 2 lines of therapy. No previous treatment for BM was performed in 67% (n = 37), while 9% had previous brain surgery (n = 5 ;) or brain radiation (n = 17 (31%). 2/55 pts never received N. Median duration of therapy in BM pts was 2.4 months (varying from 0 to 9) with a 3-months PFS of 60% (IC95% = 45 – 73). Median OS is not reached at the time of this analysis. Among 44 pts with assessment of response on BM, 10 (23%) had objective response while 21 (48%) had local progressive disease. Neurologic deterioration requiring steroids was observed in 15 pts (32%) . Updated data will be presented at the meeting. Conclusions: This is the first large study to report preliminary safety and efficacy of N in RCC pts with BM. Safety of N in this pt population appears to be acceptable, although some pts do require steroids because of brain progressive disease. Objective response in the brain was observed in 23% of pts. Further follow up is required to determine the real benefit of N in this group of mRCC pts. Clinical trial information: NCT03013335