A Phase III Randomized Trial Comparing Intermittent Versus Continuous Androgen Suppression for Patients With Prostate-Specific-Antigen Progression in the Clinical Absence of Distant Metastases Following Radiotherapy for Prostate Cancer

OBJECTIVES:

• Compare the survival of prostate cancer patients with prostate-specific antigen progression in the clinical absence of distant metastases after prior radical radiotherapy treated with intermittent androgen suppression (IAS) vs continuous androgen deprivation (CAD).
• Compare the time to the development of hormone resistance in patients treated with these regimens.
• Compare the quality of life of patients treated with these regimens.
• Compare the serum cholesterol and HDL/LDL levels at 3 years with those at baseline and compare them annually in patients treated with these regimens.
• Evaluate the duration of treatment and non-treatment intervals, time to testosterone recovery (return to pre-therapy levels), and time to recover potency in patients treated with IAS.

OUTLINE: This is a randomized, multicenter study. Patients are stratified according to prior radical prostatectomy (yes vs no), time since completion of prior radical radiotherapy (1 to 3 years vs 3 years or more), baseline prostate-specific antigen (PSA) value (3-15 ng/mL vs greater than 15 ng/mL), and prior hormonal therapy (neo-adjuvant, concurrent, or adjuvant cytoreduction in association with the radical radiotherapy treatment or prostatectomy for a maximum duration of 12 months and completed at least 12 months prior to randomization) (yes vs no). Patients are randomized to one of two treatment arms.

• Arm I: Patients undergo intermittent androgen suppression (IAS). Patients receive luteinizing hormone-releasing hormone (LHRH) analog (buserelin [BSRL], goserelin [ZDX], or leuprolide [LEUP]) and an antiandrogen (nilutamide [ANAN], flutamide [FLUT], bicalutamide [CDX], or cyproterone acetate [CPTR]) for 8 months. Patients receive LHRH analog by subcutaneous (SC) or intramuscular (IM) implant every 1-4 months beginning within 5 days of randomization and oral antiandrogen 1-3 times daily, depending on the actual LHRH analog and antiandrogen. PSA levels are monitored every 2 months. If PSA falls to normal during the 8-month treatment period, therapy stops until levels rise to 10 ng/mL, at which time IAS resumes for another 8-month period. IAS continues as long as PSA levels are controlled. At the time of disease progression, patients begin continuous hormonal treatment similar to arm II.
• Arm II: Patients undergo continuous androgen deprivation without scheduled interruptions. Patients receive LHRH analog (BSRL, ZDX, or LEUP) with an antiandrogen (ANAN, FLUT, CDX, or CPTR) OR undergo bilateral orchiectomy within 5 days of randomization and receive an antiandrogen. Patients receive LHRH analog by SC or IM implant every 1-4 months beginning within 5 days of randomization and oral antiandrogen 1-3 times daily, depending on the actual LHRH analog and antiandrogen. PSA levels are monitored every 2 months. Treatment continues until hormone resistance develops.

Patients receiving LHRH analog may begin antiandrogen therapy either prior to or simultaneously with LHRH analog and must continue antiandrogen therapy for at least 4 weeks to block tumor flare.