Background: Nivolumab has demonstrated antitumor activity and manageable safety in the single-arm, phase II CheckMate 275 study in patients with unresectable locally advanced or metastatic platinum-resistant urothelial carcinoma. We report updated results of the global population and a subanalysis of Japanese patients from this study.
Methods: Patients received nivolumab 3 mg/kg intravenously every 2 weeks until progression or unacceptable toxicity. The primary endpoint was objective response rate (ORR) confirmed by blinded independent review committee (BIRC) per Response Evaluation Criteria in Solid Tumors v1.1. Secondary endpoints included progression-free survival (PFS) by BIRC and overall survival (OS). Safety was also reported. The minimum follow-up was 21 months.
Results: Overall, 270 patients were treated with nivolumab globally; 23 patients were Japanese. In the global and Japanese populations, respectively, ORR per BIRC was 20.4% and 21.7%; median PFS was 1.9 (95% confidence interval [CI] 1.9-2.3) and 3.8 months (95% CI 1.9-7.2); and median OS was 8.6 (95% CI 6.1-11.3) and 21.0 months (95% CI 7.2-not reached). The most common any grade treatment-related adverse events were fatigue (18.1%) and diarrhea (12.2%) in the global population; the most common in the Japanese population were diarrhea (26.1%) and pyrexia (13.0%). Grade 3 or 4 treatment-related adverse events occurred in 61 (22.6%) and seven (30.4%) of the global and Japanese patients, respectively.
Conclusions: Nivolumab continues to show antitumor activity and survival in the global population of CheckMate 275. Meaningful clinical benefit was also observed in Japanese patients. No new safety signals were identified.
Keywords: Immune checkpoint inhibitor; Immunotherapy; Japanese; Metastatic urothelial carcinoma; Nivolumab.