Astellas and Pfizer’s Combination Therapy Halves Death Risk in Muscle-Invasive Bladder Cancer Patients

On October 18, 2025, results from the Phase 3 EV-303 trial were unveiled, showing that the combination of Padcev (enfortumab vedotin) and Keytruda (pembrolizumab) dramatically reduced both cancer recurrence and mortality rates in muscle-invasive bladder cancer patients ineligible for cisplatin chemotherapy. The findings were formally presented during a Presidential Symposium at the European Society of Medical Oncology Congress in Berlin.​

Key Study Findings

The EV-303 (KEYNOTE-905) trial enrolled patients with MIBC who were either ineligible or declined cisplatin-based chemotherapy—a common group left with few alternatives beyond surgery. Participants received Padcev, a targeted antibody-drug conjugate, and Keytruda, a PD-1 immune checkpoint inhibitor, both before and after surgery.

• Event-Free Survival (EFS): The combination therapy led to a 60% reduction in risk of tumor recurrence, progression, or death compared to surgery alone (Hazard Ratio (HR): 0.40; 95% Confidence Interval: 0.28-0.57; p<0.0001).​

• Overall Survival (OS): The risk of death was reduced by 50%, representing a marked improvement over historical outcomes for this patient group.​

• Long-term Benefits: After two years, 74.7% of combination therapy patients were event-free, versus only 39.4% in the surgery-alone group.​

Expert Perspectives

Jeff Legos, Pfizer’s Chief Oncology Officer, stated, “Halving the risk of death in a population with such limited options is a breakthrough for both patients and clinicians. This therapy could change the trajectory for muscle-invasive bladder cancer treatment”.​

Ahsan Arozullah, Senior VP and Head of Oncology Development at Astellas, emphasized the significance: “This combination was the first approval offering an alternative to platinum-based chemotherapy and clearly shows durable benefit”.​

Outside commentary reinforces the trial’s impact. Dr. Timir Patel, medical director at Astellas UK, remarked, “Advanced bladder cancer is an area of unmet need. This combination changes the standard of care for doctors and their patients”.​

Context and Background

Bladder cancer ranks as the ninth most common cancer globally, affecting over 600,000 individuals annually. MIBC accounts for about 30% of these cases and is notorious for invading the bladder’s muscle layer, heightening its aggressiveness and the risk of recurrence.​

For decades, cisplatin-based chemotherapy before and after bladder-removal surgery (cystectomy) was the gold standard, but nearly half of the patients remain ineligible due to age, kidney problems, or comorbid conditions. Historically, surgery alone offered limited long-term survival, underscoring the urgent need for new therapies.​

Mechanism of Action

• Padcev (Enfortumab Vedotin): Delivers cell-killing toxins directly to cancer cells via targeting Nectin-4 proteins, sparing healthy tissues—a new form of precision therapy known as antibody-drug conjugate.​

• Keytruda (Pembrolizumab): Blocks PD-1 proteins on immune cells, helping the body recognize and attack cancer cells more effectively.​

Implications for Public Health

The positive results from the EV-303 trial may redefine the standard of care for MIBC, especially for cisplatin-ineligible patients. Key practical implications include:

• Providing a viable alternative to surgery alone for patients unable to tolerate traditional chemotherapy.

• Potential for more widespread adoption once regulatory approvals are obtained, as global health authorities have been engaged for review.​

Individuals with bladder cancer and their families should speak with their care teams about evolving treatment options and clinical trials, as these new therapies may become available soon.

Limitations and Counterarguments

While the EV-303 trial presents strong evidence, several limitations remain:

• The long-term side effect profile of combined Padcev and Keytruda therapy is still being characterized, with continued follow-up required.​

• Not all MIBC patients may respond equally, and access to advanced therapies may be influenced by geography and healthcare infrastructure.

• The estimated median event-free survival for the combination group has not been reached, and mature data will be required to fully assess durability and safety.​

Practical Implications

For readers and practitioners:

• This study underscores the importance of discussing all available treatment options, including emerging therapies, with medical professionals.

• Individuals diagnosed with bladder cancer, or those at high risk, should remain informed about new developments and consider regular screenings and consultations for early detection and personalized treatment planning.

Balanced Reporting

The trial’s results are highly promising, but objectivity demands ongoing vigilance for new evidence. As further data and regulatory updates emerge, the promise of combination therapies must be measured against real-world clinical outcomes, patient selection, and overall quality of life.

Medical Disclaimer

Medical Disclaimer: This article is for informational purposes only and should not be considered medical advice. Always consult with qualified healthcare professionals before making any health-related decisions or changes to your treatment plan. The information presented here is based on current research and expert opinions, which may evolve as new evidence emerges.

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