Medivation and Astellas are planning to start a global Phase III clinical trial of enzalutamide in men with high-risk, hormone-sensitive, non-metastatic prostate cancer.
The trial is designed to evaluate the efficacy and safety of enzalutamide in patients with prostate cancer that has biochemically recurred following definitive local therapy with radical prostatectomy and/or radiation therapy.
In the US, currently there is no prescription medicine specifically approved for patients with prostate cancer.
Around 1,860 patients will be enrolled in the randomised, multi-national Phase III trial, which will be conducted at about 160 sites.
Medivation chief medical officer Dr Lynn Seely said: "It is estimated that approximately one third of men in the US experience a rising PSA, also known as biochemical recurrence, after localised therapy for the treatment of prostate cancer.
"This trial will determine if enzalutamide can delay the development of metastatic prostate cancer in high-risk men with a rapidly rising PSA.
"The initiation of this trial in collaboration with our partner Astellas showcases our mutual commitment to continue exploring the potential of enzalutamide in areas of significant unmet medical need."
During the trial, patients will be randomised into three separate groups: enzalutamide plus leuprolide acetate, enzalutamide monotherapy, or placebo plus leuprolide acetate.
Treatment with enzalutamide monotherapy will be open-label, while treatment with enzalutamide and placebo will be double-blind in combination with open-label leuprolide acetate.
Astellas Pharma chief medical officer and Astellas Pharma Global Development president Sef Kurstjens said: "Following enzalutamide's continued positive impact on overall survival and progression-free survival versus placebo in metastatic castration-resistant prostate cancer, we are looking forward to continuing to explore the medicine's potential impact on patients at earlier stages of the disease."
The trial will assess enzalutamide at a dose of 160mg to be taken orally once daily and leuprolide acetate will be given as an injection of 22.5mg once every 12 weeks for a minimum of three doses.