Pfizer-Astellas Bladder Cancer Therapy Shows 43% Survival Boost

Pfizer and Astellas Pharma have announced positive results from their late-stage clinical trial of a combination therapy for bladder cancer. The trial, which involved the use of Padcev in conjunction with Merck's Keytruda, demonstrated significant improvements in both event-free survival and overall survival rates. This breakthrough is expected to pave the way for regulatory submissions and further strengthen Pfizer's oncology portfolio.

The trial included nearly 600 patients who were unable to tolerate or refused standard chemotherapy treatments, leaving surgery as their primary option. The combination therapy, administered both pre- and post-surgery, showed a marked reduction in cancer progression and improved overall survival rates compared to surgery alone. This dual-pathway synergistic approach involves Padcev targeting high-expression Nectin-4 tumor cells with selective cytotoxicity and inducing immunogenic cell death, while Keytruda releases the PD-1 immune brake, amplifying the body's anti-tumor immune response.

This synergistic effect of direct cell toxicity and immune remodeling has shown significant benefits in metastatic disease and in muscle-invasive bladder cancer (MIBC) patients who are ineligible or refuse cisplatin. The combination therapy has demonstrated improved event-free survival (EFS) and overall survival (OS) compared to surgery alone, providing a much-needed treatment option for patients lacking effective neoadjuvant therapies. However, data from the third group, which received Keytruda monotherapy plus surgery, is not yet mature.

These positive interim results support Pfizer's efforts to establish Padcev as a cornerstone oncology drug, a strategy bolstered by the company's acquisition of Seagen Inc. for 430 billion dollars. The trial's success in meeting its primary endpoint of delaying cancer progression and ultimately improving survival rates is a significant milestone. However, the final data for the third group, which received Keytruda monotherapy plus surgery, is still pending.

Pfizer is banking on its oncology business to drive growth as demand for its COVID-19 vaccine and treatment wanes and it faces patent expirations. The acquisition of Seagen, completed in late 2023, is part of Pfizer's broader strategy to transition into a leading player in the oncology market. The company has not yet disclosed detailed trial data but has promised to present the complete results at an upcoming medical conference.