Pfizer and Astellas Announce Positive Phase 3 Results for Padcev in Bladder Cancer

Pfizer and Astellas Pharma have announced encouraging findings from a pivotal clinical study concerning their antibody-drug conjugate, Padcev (enfortumab vedotin-ejfv), used in treating bladder cancer. This phase 3 study, designated as EV-302 or KEYNOTE-A39, has been examining the effects of Padcev in tandem with Merck's PD-1 inhibitor, Keytruda (pembrolizumab), in patients experiencing previously untreated advanced or metastatic urothelial cancer (UC).

Globally, bladder cancer affects approximately 614,000 individuals annually, with urothelial cancer comprising about 90% of these cases. Last October, the combination of Padcev and Keytruda received approval for treating UC from the Medicines and Healthcare products Regulatory Agency. This followed similar endorsements from the United States Food and Drug Administration and the European Commission. These approvals were predicated on the promising outcomes of the EV-302 trial, which demonstrated that the Padcev and Keytruda therapy significantly improved overall survival (OS) and progression-free survival (PFS) compared to traditional platinum-based chemotherapy.

Newly released data, unveiled at this year's American Society of Clinical Oncology Genitourinary Cancers Symposium, encompass an additional 12 months of follow-up. These findings revealed that the Padcev and Keytruda combination reduced the mortality risk by 49% relative to chemotherapy. Specifically, the median overall survival was reported as 33.8 months for the combination therapy, compared to just 15.9 months for patients receiving chemotherapy. Furthermore, the dual therapy reduced the risk of disease progression or death by 52%, with patients experiencing a median progression-free survival of 12.5 months versus 6.3 months under chemotherapy.

The research also highlighted that the overall survival advantage was apparent across all pre-specified patient subgroups, including those eligible and ineligible for cisplatin treatment. The safety profile of this combination therapy was consistent with earlier studies.

Roger Dansey, Pfizer’s chief oncology officer, emphasized the challenges faced by bladder cancer patients, particularly during advanced stages when treatment options are limited. He remarked on the updated EV-302 results, noting their demonstration of sustained long-term efficacy in a diverse patient population. This includes both cisplatin eligible and ineligible patients, underscoring the combination's potential to transform the treatment paradigm for urothelial cancer.

Ahsan Arozullah, senior vice president and head of oncology development at Astellas, also commented on the findings. He pointed out that the combination of Padcev and Keytruda was the first to provide an alternative to the long-standing standard of platinum-based chemotherapy for first-line treatment of locally advanced or metastatic UC. He expressed satisfaction with the additional follow-up results from the EV-302 trial, highlighting the durable benefits offered by this treatment regimen.

Overall, the results from the EV-302 trial underscore the potential of Padcev and Keytruda to offer a more effective and safer treatment alternative for patients with advanced urothelial cancer, marking a significant milestone in the ongoing battle against this challenging disease.