A Study of Enzalutamide Plus the Glucocorticoid Receptor Antagonist Relacorilant Versus Placebo for Patients With High-risk Localized Prostate Cancer

Relacorilant is an antiglucocorticoid which is under development by Corcept Therapeutics for the treatment of Cushing's syndrome. It is being used in this study as an experimental drug combined with other treatments for prostate cancer.

Enzalutamide, sold under the brand name Xtandi, is a nonsteroidal antiandrogen medication which is used in the treatment of prostate cancer.

This would be a sugar pill consisting of 2 softgels. This is not an experimental drug or treatment.

All participants in this study, who meet the requirements to participate, will get Androgen Deprivation Therapy (ADT; a form of hormone therapy) continuously before their radical prostatectomy surgery. As part of this study, ADT consists of one injection every 1-3 months. In this study, ADT is a gonadotropin releasing hormone (GnRH) agonists or antagonist; the choice of which brand of ADT to use is up to your treating physician. GnRH agonists and antagonists are drugs that lower the production of androgens (male hormones) in your body. Prostate cancer cells usually require androgens, such as testosterone, to grow. Androgen Deprivation Therapy (ADT) has been approved by United Stated Food and Drug Administration (US FDA) to treat patients with prostate cancer but is not approved to treat patients prior to prostatectomy.

Radical prostatectomy is surgery to remove the entire prostate gland and surrounding lymph nodes to treat men with localized prostate cancer.