Seattle Genetics and Astellas Pharma have reported that Padcev (enfortumab vedotin-ejfv) achieved its primary endpoint of overall survival in a Phase III clinical trial in adults with locally advanced or metastatic urothelial cancer.

The EV-301 trial compared the drug to chemotherapy in patients who received prior treatment with platinum-based chemotherapy and a PD-1/L1 inhibitor.

Planned interim analysis found significant improvement in overall survival (OS) in patients treated with Padcev, with a 30% decrease in risk of death.

The drug also significantly improved progression-free survival (PFS), a secondary endpoint, demonstrating a 39% decrease in risk of disease progression or death.

The most frequent Padcev-related Grade 3 or greater adverse event(s) observed in more than 5% of patients are rash, hyperglycemia, decreased neutrophil count, fatigue, anaemia and decreased appetite.

Astellas Pharma senior vice-president and oncology therapeutic area head Andrew Krivoshik said: “EV-301 is the first randomised trial to show overall survival results compared to chemotherapy in patients with locally advanced or metastatic urothelial cancer who previously have received platinum-based treatment and a PD-1 or PD-L1 inhibitor, and we are encouraged by the potential this may have in helping patients who have otherwise limited alternatives.”

The companies plan to submit these data to the US Food and Drug Administration (FDA) as the confirmatory trial. The drug obtained accelerated approval last year.

Apart from the US, EV-301 is expected to support registrations in other global markets.

Padcev is an antibody-drug conjugate (ADC) acting against Nectin-4, a protein present on the surface of cells and highly expressed in bladder cancer.

The global, multi-centre, open-label, randomised EV-301 trial compared the drug to chemotherapy, docetaxel, paclitaxel or vinflunine, in a total of about 600 subjects.

While the primary endpoint is overall survival, the secondary endpoints included progression-free survival, duration of response, overall response rate, safety, tolerability and quality-of-life parameters.