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Testosterone and ZEN-3694 followed by Enzalutamide and ZEN-3694 for the Treatment of Asymptomatic Patients with Metastatic Castration-Resistant Prostate Cancer, The COSMYC Trial

Trial Status: active

This phase II trial tests how well bipolar androgen therapy (BAT) with testosterone cypionate in combination with ZEN-3694 followed by the combination of enzalutamide and ZEN-3694 works in decreasing tumor size in patients with prostate cancer that has spread from where it first started to other places in the body (metastatic) and continues to grow and spread despite interventions to block hormone production (castration-resistant). Testosterone cypionate, a male hormone (an androgen), works by replacing the testosterone that is normally produced naturally in the body. BAT works by alternating between periods of high and low testosterone levels. This may keep the prostate tumor cells from adapting to low androgen levels and may improve sensitivity to treatment, as well as quality of life and sexual function. ZEN-3694 is an inhibitor of a family of proteins called the bromodomain and extra-terminal (BET). It may prevent the growth of tumor cells that over produce BET protein. Enzalutamide, a type of antiandrogen, binds to proteins called androgen receptors (AR), which are found in some prostate tumor cells. These proteins bind to androgens and may cause tumor cells to grow. Enzalutamide blocks these proteins and may keep tumor cells from growing. Giving BAT with testosterone cypionate in combination with ZEN-3694 followed by the combination of enzalutamide and ZEN-3694 may decrease tumor size and improve survival in patients with asymptomatic metastatic castration-resistant prostate cancer (CRPC).