Wednesday, June 23, 2021 The REC4 study, A Phase 3 RandOmized Study Comparing PERioperative Nivolumab vs. Observation in Patients with Renal Cell Carcinoma Undergoing Nephrectomy (PROSPER RCC) has been closed to accrual after reaching its accrual target. Thank you to everyone who has contributed to this study. For more information please visit the CCTG REC4 study page.