This study consists of two parts. The purpose of PART 1 is to test non-inferiority of ASP3550 to goserelin acetate with respect to the cumulative castration rate in terms of serum testosterone when ASP3550 or goserelin acetate is administered for one-year in patients with prostate cancer.
The patients assigned to receive ASP3550 and completed the treatment in PART 1 are eligible for the treatment in PART 2, and will receive ASP3550 maintenance dose subcutaneously for additional term. The long-term safety, efficacy and PK of the continued ASP3550 treatment will be assessed in PART 2.
