Keynote-676: Phase 3 study of bacillus calmette-guerin (BCG) with or without pembrolizumab (pembro) for high-risk (HR) non–muscle invasive bladder cancer (NMIBC) that is persistent or recurrent following BCG induction.

Abstract

TPS502 Background: Intravesical instillation of BCG is the standard of care for patients with HR NMIBC. However, many patients have persistent/recurrent HR NMIBC after BCG induction and are at a particularly increased risk for progression, representing a significant unmet need. Programmed cell death ligand 1 (PD-L1) expression in the tumor microenvironment may attenuate responses to BCG. KEYNOTE-676 is a randomized, comparator-controlled, phase 3 trial to evaluate the efficacy and safety of the PD-1 inhibitor pembro plus BCG in patients with persistent/recurrent HR NMIBC after BCG therapy. Methods: Adult (≥18 years) patients with histologically confirmed persistent/recurrent HR NMIBC of the bladder after adequate BCG induction therapy are eligible. Patients are required to have undergone cystoscopy/transurethral resection of bladder tumor within 12 weeks prior to randomization, to have no concurrent extravesical disease, and to have ECOG performance status score 0-2, adequate organ function, and tissue for biomarker analysis. Patients will be randomly assigned 1:1 to continue on BCG therapy alone or receive BCG plus pembro 200 mg every 3 weeks. Treatment will be stratified by carcinoma in situ (CIS) histology (presence/absence), PD-L1 combined positive score (≥10/˂10), and timing of NMIBC persistence/recurrence (0 to ≤6, ˃6 to ≤12, or ˃12 to ≤24 mo). Primary end point is complete response rate in participants with CIS. Secondary end points will include event-free survival, patient-reported outcomes, and safety. Responses will be assessed by cystoscopy and blinded independent central review of urine cytology and biopsy (as applicable) every 12 weeks for years 1-2 and every 24 weeks for years 3-5 and by computed tomography urography every 18 months through year 5. Treatment will continue with pembro for up to 2 years and BCG for 3 years or until pathology-confirmed HR NMIBC persistence, recurrence, or disease progression, unacceptable toxicity, or patient/physician decision to withdraw. Recruitment will begin November 2018 and will continue until ~550 patients are enrolled. (NCT03711032). Clinical trial information: NCT03711032.