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

Background

Guidelines for prostate cancer treatment suggest that intermittent androgen deprivation (IAD) can be considered for certain patients.

Objective

To 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 participants

This 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.

Intervention

Each induction period included a starting dose of degarelix 240 mg, and thereafter 80 mg once a month for 6 mo, followed by off-treatment periods.

Outcome measurements and statistical analysis

The 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 limitations

Of 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.

Conclusions

IAD 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 summary

Guidelines 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 registration

Clinicaltrials.gov identifier NCT00801242.