KEYNOTE-B15: This study is testing whether a new combination of anti-cancer drugs work more effectively than the current standard treatment with chemotherapy when given in addition to surgery in people with muscle invasive bladder cancerA Phase 3, Randomized, Open-label Study to Evaluate Perioperative Enfortumab Vedotin Plus Pembrolizumab (MK-3475) Versus Neoadjuvant Gemcitabine and Cisplatin in Cisplatin-eligible Participants With Muscle-invasive Bladder Cancer (KEYNOTE-B15 / EV-304)

Summary

Eligible participants will be randomly allocated to either the Experimental Arm or the Active Comparator Arm. In the Experimental Arm, participants will receive 4 cycles (each lasting 21 days) of an antibody-drug conjugate (enfortumab vedotin [EV]) plus immunotherapy (pembrolizumab). EV will be given via intravenous infusion (IV) at a dose of 1.25mg on Day 1 and Day 8 every 3 weeks, and pembrolizumab will be given at a dose of 200mg via IV on Day 1 every 3 weeks. This will then be followed by a surgical procedure consisting of a radical cystectomy and a pelvic lymph node dissection. Following this, participants will receive 5 cycles of EV via IV infusion plus 13 cycles of pembrolizumab via IV. The total treatment duration for this arm is up to approximately 1 year. In the Active Comparator Arm, participants will receive 4 cycles of standard of care chemotherapy (gemcitabine 1000mg/m^2 on day 1 and Day 8 every 3 weeks via IV infusion, plus cisplatin 70mg/m^2 on Day 1 every 3 weeks via IV infusion). This will then be followed by a radical cystectomy and a pelvic lymph node dissection. The total treatment duration for this arm is up to approximately 3 months.