Astellas and Pfizer reveal positive results for Xtandi

Research data follows phase 3 EMBARK trial and involves men with non-metastatic prostate cancer

Astellas has announced positive results from its phase 3 EMBARK trial which has been studying Xtandi among men with non-metastatic hormone-sensitive prostate cancer with high-risk biochemical recurrence.

The patients enrolled in the trial were randomised through three study arms – Xtandi plus leuprolide, placebo plus leuprolide and Xtandi monotherapy. The research met its primary endpoint with a clinically meaningful and statistically significant improvement in metastasis-free survival (MFS) for patients treated with Xtandi – enzalutamide – in addition to leuprolide versus placebo plus leuprolide.

During the analysis, a positive trend in the key secondary endpoint of overall survival (OS) was also observed. Meanwhile, patients in the trial will be followed for a subsequent final OS study.

The trial also met another key secondary endpoint with a statistically significant and clinically meaningful improvement in MFS for patients treated with Xtandi monotherapy versus placebo plus leuprolide.

Further key secondary endpoints reached statistical significance, including the amount of time to PSA progression and time to initial use of new antineoplastic therapy. Also, no new safety signals have been observed to date, which is consistent with the established safety profile of the therapy.

Chris Boshoff, chief development officer, oncology and rare disease at Pfizer Global Product Development, explained: “The top line findings from EMBARK are highly encouraging. We look forward engaging with health authorities to potentially bring Xtandi to men with non-metastatic hormone sensitive prostate cancer and high-risk biochemical recurrence.”

Ahsan Arozullah, senior vice president and head of development therapeutic areas at Astellas, concluded: “While current treatment options for localised prostate cancer are intended to be curative, some men remain at higher risk for biochemical recurrence following primary treatment, which may result in metastases.”

He added: “The EMBARK trial is the first study to demonstrate a statistically significant improvement in MFS using the combination of Xtandi plus leuprolide in men with this stage of disease.”