Planned survival analysis from KEYNOTE-045: Phase 3, open-label study of pembrolizumab (pembro) versus paclitaxel, docetaxel, or vinflunine in recurrent, advanced urothelial cancer (UC).

4501Background: Second-line chemotherapies (chemo) for advanced UC have limited clinical benefit (OS, 7-9 mo). Data from the open-label, phase 3 KEYNOTE-045 study (NCT02256436) showed significantly longer OS with pembro v chemo (median, 10.3 v 7.4 mo; hazard ratio [HR], 0.73; P = 0.002) in recurrent, advanced UC. Data from a planned survival analysis are presented. Methods: Pts had histologically or cytologically confirmed UC, progression after platinum, ECOG PS 0-2, measurable disease (RECIST v1.1), and ≤2 lines of systemic therapy. Pts were randomly assigned 1:1 to pembro 200 mg Q3W or investigator’s choice of paclitaxel 175 mg/m2 Q3W, docetaxel 75 mg/m2 Q3W, or vinflunine 320 mg/m2 Q3W. Primary efficacy end points were OS and PFS (RECIST v1.1, blinded central review). ORR (RECIST v1.1, blinded central review) was a secondary end point. Results: 542 pts were enrolled (pembro, 270; chemo, 272). Baseline characteristics were generally similar between arms. As of Jan 18, 2017, median follow-up was 18.5 mo ...