Dr Galsky on the Background of the KEYNOTE-B15 Trial in MIBC

“Radical cystectomy is standard treatment for patients with MIBC, but we know that with radical cystectomy alone, a substantial subset of patients will develop metastatic recurrence months to years after surgery. That provides the rationale for integrating systemic therapy along with radical cystectomy.”

Matthew D. Galsky, MD, the deputy director and director of genitourinary medical oncology; codirector of the Center of Excellence for Bladder Cancer; and a professor of medicine, hematology and medical oncology, and urology, at the Mount Sinai Tisch Cancer Center, discussed the background of the phase 3 KEYNOTE-B15/EV-304 trial (NCT04700124), which examined enfortumab vedotin-ejfv (EV; Padcev) in combination with pembrolizumab (Keytruda) for the neoadjuvant and adjuvant treatment of patients with muscle-invasive bladder cancer (MIBC) who were eligible for cisplatin-containing therapy and radical cystectomy.

Galsky began by noting that radical cystectomy is a standard treatment option for patients with MIBC, but a significant portion of patients will go on to develop metastatic recurrence after the procedure, providing the clinical rationale for integrating systemic therapy. Neoadjuvant cisplatin-based chemotherapy has also become a standard of care, as it can lead to an overall survival benefit in patients with MIBC, he added.

Prior data from the phase 3 KEYNOTE-905/​EV-303 trial (NCT03924895) demonstrated that neoadjuvant and adjuvant EV plus pembrolizumab led to improved efficacy outcomes for patients with cisplatin-ineligible MIBC vs surgery alone, Galsky explained. These data provided the rationale to evaluate the combination for the treatment of patients in the same population who were eligible to receive cisplatin-based chemotherapy, he concluded.

During the 2026 Genitourinary Cancers Symposium, Galsky presented data from KEYNOTE-B15.

Disclosures: Galsky holds consulting or advisory roles with Abbvie, Bristol-Myers Squibb, EMD Serono, Gilead Sciences, Janssen, Merck, and Pfizer. He also received research funding from AstraZeneca (Inst), Bristol-Myers Squibb (Inst), Dendreon (Inst), Genentech/Roche (Inst), Janssen Oncology (Inst), Merck (Inst), and Novartis (Inst). He has patents, royalties, or other intellectual property including: METHODS AND COMPOSITIONS FOR TREATING CANCER AND RELATED METHODS. MOUNT SINAI SCHOOL OF MEDICINE July 2012 Application number: 20120322792.