PURPOSE The integration of immunotherapy in the perioperative setting of muscle-invasive urothelial carcinoma (MIUC) appears promising. SAKK 06/17 investigated the addition of neoadjuvant durvalumab to gemcitabine/cisplatin (GC) chemotherapy followed by radical surgery and adjuvant checkpoint inhibition with durvalumab. PATIENTS AND METHODS SAKK 06/17 was an investigator-initiated, open-label, single-arm phase II study including cisplatin-fit patients with stage cT2-T4a cN0-1 operable MIUC. Four cycles of neoadjuvant GC in combination with four cycles of durvalumab (start with GC cycle 2) were administered, followed by radical surgery. Adjuvant durvalumab was given for 10 cycles. The primary end point was event-free survival (EFS) at 2 years. RESULTS Sixty one patients were accrued at 12 sites. The full analysis set consisted of 57 patients, 54 (95%) had bladder cancer. Median follow-up was 40 months. The primary end point was met, with EFS at 2 years of 76% (one-sided 90% CI [lower bo