Neoadjuvant Nivolumab with or without Ipilimumab for Cisplatin-Ineligible Patients with Muscle-Invasive Bladder Cancer

Abstract Purpose: Many patients with muscle-invasive bladder cancer (MIBC) are ineligible for cisplatin-based therapy. We conducted a phase II trial of neoadjuvant nivolumab ± ipilimumab for cisplatin-ineligible patients. Patients and Methods: Patients with MIBC were enrolled in two consecutive cohorts: (i) nivolumab alone and (ii) ipilimumab/nivolumab. A third cohort with alternative dosing was planned. The primary endpoint was eligibility for cystectomy ≤60 days after last treatment. Correlative analyses were performed, with the PURE-01 trial used as an independent dataset. Results: Fifteen patients enrolled onto each cohort. In cohorts 1 and 2, 12 of 15 and eight of 15 were eligible for cystectomy within 60 days, respectively. Due to cohort 2’s failure to meet the primary endpoint, cohort 3 was not initiated. With nivolumab alone, four patients achieved Conclusions: Among cisplatin-ineligible patients with MIBC, nivolumab alone was well tolerated. Ipilimumab/nivolumab caused toxicity that delayed cystectomy. Cases of progression before cystectomy indicated insufficient efficacy of pure neoadjuvant immunotherapy for unselected patients. Despite low response rates, some patients experienced sustained clinical CR without cystectomy.