Degarelix as an Intermittent Androgen Deprivation Therapy for One or More Treatment Cycles in Patients with Prostate Cancer

Abstract

BackgroundGuidelines for prostate cancer treatment suggest that intermittent androgen deprivation (IAD) can be considered for certain patients. ObjectiveTo evaluate the efficacy and safety of degarelix as IAD for one or more treatment cycle(s) in prostate cancer patients requiring androgen deprivation. Design, setting, and participantsThis open-label uncontrolled multicenter study included patients with prostate-specific antigen (PSA) >4 to 50 ng/ml or PSA doubling time <24 mo. Induction included 7-mo treatment. Off-treatment period started when PSA was ≤4 ng/ml and lasted up to 24 mo based on PSA and testosterone levels. Treatment was reinitiated when PSA was >4 ng/ml. InterventionEach induction period included a starting dose of degarelix 240mg, and thereafter 80mg once a month for 6 mo, followed by off-treatment periods. Outcome measurements and statistical analysisThe primary end point was time to PSA >4 ng/ml. Secondary end points were subgroup analysis of the primary end point, time to testosterone >0.5 and >2.2 ng/ml, quality of life (QoL), and sexual function during the first off-treatment period. Results and limitationsOf 213 patients in the first induction period, 191 entered the first off-treatment period, 35 patients entered the second induction, and 30 entered the second off-treatment period. Only two patients entered the third cycle. Median time to PSA >4 ng/ml and duration of first off-treatment period was 392 d each. Significant differences in time to PSA >4 ng/ml were observed between subgroups stratified by prognostic factors (previous curative treatment, cancer stage, PSA levels, and Gleason scores). Time to testosterone >0.5 and >2.2 ng/ml was 112 and 168 d, respectively. Change in QoL remained nonsignificant, and sexual function gradually improved during the off-treatment period. Adverse events were fewer during the off-treatment period and subsequent treatment cycles. ConclusionsIAD with degarelix resulted in an improvement in sexual function commensurate with increased testosterone levels while PSA remained suppressed. The treatment for one treatment cycle or more was well tolerated. Patient summaryGuidelines for prostate cancer treatment suggest that intermittent androgen deprivation (IAD) can be considered for certain patients. IAD with degarelix resulted in improved sexual function commensurate with increased testosterone levels while prostate-specific antigen remained suppressed. The treatment for one treatment cycle or more was well tolerated. Trial registrationClinicaltrials.gov identifier NCT00801242.