Background: In the open-label, single-arm, phase 2 CheckMate 275 trial, objective response rate (ORR) for patients (pts) with metastatic urothelial carcinoma (mUC) with nivolumab (NIVO) was 20.4% with minimum follow-up of 21.3 mo. Here, we report updated efficacy and safety data with minimum follow-up of 33.7 mo. Methods: Pts with platinum-resistant locally advanced or metastatic urothelial carcinoma received NIVO 3 mg/kg until disease progression or unacceptable toxicity. The primary endpoint was ORR by blinded independent review committee (BIRC) by RECIST v1.1 (including duration of response [DOR]). Secondary endpoints included progression-free survival (PFS) by BIRC, overall survival (OS), and ORR per investigator. Efficacy was evaluated in all treated pts and by tumor PD-L1 expression. Safety and PFS by investigator were exploratory endpoints. Results: ORR by BIRC was 20.7% (95% CI 16.1–26.1) including 18 (7%) complete responses (CR; with 1 additional CR since the last report; Table). ORR per investigator was similar (24.8%). Median DOR by BIRC was 20.3 mo (95% CI 11.5–31.3). Of 56 pts with best overall response (BOR) of CR or partial response (PR), 59% had a DOR ≥12 mo. Median PFS (mPFS) was 1.9 mo per BIRC (95% CI 1.9–2.3; Table) and 2.0 mo per investigator (95% CI 1.9–2.5). Median OS (mOS) was 8.6 mo (95% CI 6.1–11.3; Table). 12, 24, and 36-mo OS rates were 40%, 30%, and 22%. While efficacy was numerically higher in pts with tumor PD-L1 expression ≥1%, efficacy was observed in all pts (Table). Any-grade treatment-related adverse events occurred in 69% of pts (grade 3–4, 25%), mostly (59%) within the first 3 mo of initiating therapy. Conclusions: With long-term follow-up from CheckMate 275, NIVO continues to provide durable antitumor activity in pts with mUC. No new safety signals were noted. Clinical trial information: NCT02387996