Merck: KEYTRUDA and Padcev Cut Bladder Cancer Risks Pre- and Post-Surgery

Study Overview

The Phase 3 KEYNOTE-905 trial demonstrated that the combination of KEYTRUDA and Padcev significantly reduced the risk of event-free survival events by 60% and the risk of death by 50% in patients with muscle-invasive bladder cancer (MIBC) who are ineligible for cisplatin-based chemotherapy. These results were presented at the European Society for Medical Oncology (ESMO) Congress 2025.

Trial Details

The trial involved 595 patients with MIBC, comparing the combination therapy to surgery alone. Patients were divided into three arms: Arm A received neoadjuvant KEYTRUDA followed by surgery and adjuvant KEYTRUDA; Arm B underwent surgery alone; Arm C received neoadjuvant KEYTRUDA plus Padcev, followed by surgery and adjuvant treatment with both drugs.

Results

After a median follow-up of 25.6 months, the combination therapy showed a statistically significant improvement in event-free survival and overall survival. The median event-free survival was not reached for the combination therapy, compared to 15.7 months for surgery alone. The pathologic complete response rate increased from 8.6% with surgery alone to 57.1% with the combination therapy.

Safety Profile

The safety profile of KEYTRUDA plus Padcev was consistent with known safety profiles of each agent. Treatment-emergent adverse events occurred in all patients receiving the combination therapy, with Grade ≥3 events in 71.3% of patients.

Future Implications

These findings suggest a potential shift in treatment practices for MIBC patients ineligible for cisplatin, addressing a critical unmet need. The results will be shared with regulatory authorities worldwide.