 6. For patients who received combined androgen blockade a GnRH antagonist, analog or orchiectomy in combination with continuous antiandrogen not including enzalutamide, disease progression must have been determined after antiandrogen discontinuation as defined below: a For patients receiving flutamide: at least one of the PSA values must be obtained 4 weeks or more after flutamide discontinuation.; b For patients receiving bicalutamide or nilutamide: at least one of the PSA values must be obtained 6 weeks or more after antiandrogen discontinuation.; However, in patients who did not respond to combined androgen blockade or who showed a decline in PSA for 3 months or less after an antiandrogen was administered as a second-line or later intervention, no withdrawal response will be expected and therefore disease progression will be determined provided at least one rising PSA value is obtained 2 weeks or more after antiandrogen discontinuation. 