A drug used to treat prostate cancer that has not spread to other parts of the body. It is used in patients whose cancer is castration resistant (has not responded to treatments that lower testosterone levels). Apalutamide binds to proteins called androgen receptors, which are found in some prostate cancer cells. These proteins bind to androgens (male hormones) and may cause cancer cells to grow. Apalutamide blocks these proteins and may keep cancer cells from growing. It is a type of antiandrogen. Also called Erleada.