A Phase II, Randomized, Multicenter Study Comparing 10 Months versus 4 Months of Degarelix Therapy in Prolonging the Off Treatment Interval in Men with Localized Prostate Cancer Receiving Intermittent Androgen Deprivation Therapy for Biochemical Recurrence following Radical Local Therapy

Clinical trials in men initiating intermittent androgen deprivation therapy have used a range of induction durations between 3 and 12 months. We sought to determine whether the duration of induction androgen deprivation therapy would influence the duration of the off treatment interval and the recovery of serum testosterone.This was a prospective, randomized, open label study. Men with biochemical recurrence after local therapy for prostate cancer and a negative bone scan were randomized to 4 and 10 months of monthly degarelix. The first dose was 240 mg and subsequent doses were 80 mg per month. Quality of life was evaluated by the I-PSS (International Prostate Symptom Score), the PAS-SFI (Problem Assessment Scale of the Sexual Function Index) and the FACT-P (Functional Assessment of Cancer Therapy-Prostate).A total of 90 patients were randomized, including 43 to 4 months and 47 to 10 months of treatment. There was no difference in any relevant baseline laboratory parameter, including prostate specific antigen and testosterone. There was no difference between the 2 treatment groups in time off treatment (HR 1.51, 95% CI 0.60-3.84, p = 0.38). Actuarial median time to testosterone recovery to 8.0 nmol/l or greater was 8.05 months (95% CI 4.34-39.89) in the 10-month treatment arm and 6.24 months (95% CI 5.45-15.90) in the 4-month treatment arm. The log rank test showed no statistical significance between the 2 treatment groups in time to testosterone recovery (p = 0.8392). There was no difference in the testosterone recovery rate between the 2 arms. Men younger than 65 years had a considerably shorter interval off treatment and time to testosterone recovery. There was a lesser adverse effect on quality of life at the end of treatment in the 4-month than in the 10-month arm.In men with biochemical recurrence who initiated intermittent androgen deprivation therapy with degarelix no difference was observed in the duration of the off treatment interval or the rate of testosterone recovery whether they received 4 or 10 months of induction androgen deprivation therapy.