Abstract 1738P
Background
Pathological responses and early survival outcomes of patients (pts) with muscle-invasive bladder cancer (MIBC) treated with single-agent pembrolizumab and radical cystectomy (RC) within the PURE-01 study (NCT02736266) were encouraging.
Methods
The intention-to-treat (ITT) population included 155 pts, whereas 125 received pembrolizumab and RC without additional chemotherapy. Event-free survival (EFS) was defined as the time from the first cycle of pembrolizumab until radiographic disease progression precluding RC, initiation of neoadjuvant chemotherapy (NAC), recurrence after RC, or death from any cause. Other endpoints were recurrence-free survival (RFS) and overall survival (OS). Multivariable Cox regression analyses (MVA) evaluated clinical and biomarkers predictors of events after treatment.
Results
Overall, 143 (92.3%) patients underwent RC, 57 pts (39.9%) achieved an ypT0N0 and 83 patients (58%) achieved a downstaging to ypT1/a/isN0. After a median [interquartile range (IQR)] follow-up of 39 (30-47) months, 3-year EFS was 74.4% [95% confidence interval (CI): 67.8-81.7] in ITT population. 36-month OS in the ITT population was 83.8% (95% CI: 77.8- 90.2). Within the cohort of pts who did not receive additional chemotherapy (n=125), 3-year RFS (95% CI) was 96.3% (91.6-100) for ypT0N0, 96.1% (89-100) for ypT1/a/isN0, 74.9% (60.2-93) for ypT2-4N0, and 58.3% (36.2-94.1) for ypN+ pts. 3-year EFS was 83% (76-92) and 63% (53-77) in pts with PD-L1 combined positive score (CPS) ≥ 10% (n=87) and <10% (n=65), respectively. Overall, 8 pts refused to undergo RC: 5 of them achieved ypT0, 1 ypTa and 1 had MIBC at re-TURBT. To date, none of them had relapse. Higher CPS [hazard ratio (HR): 0.98, 95% CI: 0.96-0.99; p=0.01] was associated with lower rates of events, while clinical T3-4 stage (HR: 2.55, 95% CI: 1.18-5.51; p=0.01) was associated with higher rates of events at MVA.
Conclusions
Updated follow-up confirms initial findings from PURE-01, and strengthen the role of single-agent pembrolizumab before RC in PD-L1+ pts. Further analyses on the surrogate value of pathological response are ongoing, and OS data is maturing. These results warrant the ongoing randomized validation of the Keynote-905 trial (NCT03924895).
Clinical trial identification
NCT02736266.
Editorial acknowledgement
Legal entity responsible for the study
IRCCS Ospedale San Raffaele.
Funding
Merck Inc.
Disclosure
A. Necchi: Financial Interests, Institutional, Research Grant: Merck, AstraZeneca, Ipsen, BMS, Gilead; Financial Interests, Personal, Invited Speaker: Roche, Janssen, Bayer, Astellas, AstraZeneca, Merck, Clovis Oncology; Financial Interests, Invited Speaker: Incyte, Pfizer; Non-Financial Interests, Leadership Role: Global society of Rare Genitourinary Tumors (GSRGT). All other authors have declared no conflicts of interest.