Long-term Tolerability and Efficacy of Degarelix: 5-Year Results From a Phase III Extension Trial With a 1-Arm Crossover From Leuprolide to Degarelix

ObjectiveTo demonstrate the safety and efficacy of up to 5 years of degarelix treatment and the effects of crossing over from leuprolide to degarelix in the extension phase of a phase III pivotal 1-year trial.MethodsPatients receiving degarelix who completed the 1-year trial continued on 80 mg (n = 125) or 160 mg (n = 126) maintenance doses. Patients who received leuprolide were rerandomized to degarelix 240/80 mg (n = 69) or 240/160 mg (n = 65). Safety and tolerability were assessed (primary end point), as well as testosterone and prostate-specific antigen levels and prostate-specific antigen progression–free survival (secondary end points).ResultsAdverse event frequency was similar between both the groups. Adverse events included initial injection site reactions, hot flushes, and increased weight. Testosterone and prostate-specific antigen values during the extension study were similar to those seen during the 1-year trial in patients who continued on degarelix or crossed over from leuprolide. The prostate-specific antigen progression–free survival hazard rate was decreased significantly after the crossover in the leuprolide to degarelix group (from 0.20 to 0.09; P = .002), whereas in patients who continued on degarelix, the rate did not change significantly. In patients with baseline prostate-specific antigen >20 ng/mL, the same hazard rate change pattern was observed on crossover (from 0.38 to 0.19; P = .019).ConclusionDegarelix was well tolerated; no safety concerns were identified. The significant prostate-specific antigen progression–free survival benefit established for degarelix over leuprolide during year 1 remained consistent at 5 years.