Seattle Genetics, Astellas Say Phase 3 Trial Of PADCEV Meets Primary Endpoint - Quick Facts

(RTTNews) - Biotechnology company Seattle Genetics, Inc. (SGEN) and Japanese pharmaceutical company Astellas Pharma Inc. (ALPMY, ALPMY) announced Friday that a phase 3 trial of PADCEV (enfortumab vedotin-ejfv) met its primary endpoint of overall survival compared to chemotherapy.

The results were reviewed by an independent Data Monitoring Committee following a planned interim analysis. The trial stopped early due to positive results at planned interim analysis.

PADCEV is a first-in-class antibody-drug conjugate (ADC) that is directed against Nectin-4, a protein located on the surface of cells and highly expressed in bladder cancer.

In the trial, PADCEV significantly improved overall survival (OS), with a 30 percent reduction in risk of death. PADCEV also significantly improved progression-free survival (PFS), a secondary endpoint, with a 39 percent reduction in risk of disease progression or death.

The global EV-301 clinical trial compared PADCEV to chemotherapy in adult patients with locally advanced or metastatic urothelial cancer who were previously treated with platinum-based chemotherapy and a PD-1/L1 inhibitor.

The EV-301 trial is a global, multicenter, open-label, randomized phase 3 trial designed to evaluate PADCEV versus physician's choice of chemotherapy (docetaxel, paclitaxel or vinflunine) in approximately 600 patients with locally advanced or metastatic urothelial cancer who were previously treated with a PD-1 or PD-L1 inhibitor and platinum-based therapies.

The results will be submitted to the U.S. Food and Drug Administration (FDA) as the confirmatory trial following the drug's accelerated approval in 2019. EV-301 is also intended to support global registrations.

Seattle Genetics and Astellas are co-developing PADCEV under a 50:50 worldwide development and commercialization collaboration that was entered into in 2007 and expanded in 2009.