Degarelix associated with lower risk of PSA recurrence, death vs. leuprolide

Degarelix (Firmagon) is as effective as leuprolide (Lupron Depot) in reducing and sustaining castrate levels of testosterone, but during the first year of treatment, patients receiving degarelix have a significantly lower risk of PSA progression or death than those receivingleuprolide, according to a study presented at the Society of Urologic Oncology annual meeting in Bethesda, MD.

Prostate cancer patients who received injectable degarelix, 240/80 mg/month, had a recurrence rate of 7.7% during the first year of treatment compared with 12.9% of patients treated with leuprolide, 7.5 mg/month (p=.05). Patients being treated with degarelix also had longer time to recurrence compared with those on leuprolide (p=.04), according to study co-authors Neal D. Shore, MD, of Grand Strand Urology, Myrtle Beach, SC, and E. David Crawford, MD, of the University of Colorado, Denver, who presented the results.

In the phase III multicenter trial, 610 prostate cancer patients were randomized to a starting dose of degarelix, 240 mg for 1 month, followed by monthly maintenance doses of 80 mg (207 patients) or 160 mg (202 patients), or leuprolide, 7.5 mg/month (201 patients).

PSA recurrence was 12.9% for leuprolide, 7.5 mg/month, compared with 7.7% for degarelix. The probability of completing the study without experiencing PSA recurrence by day 364 was 91.1% for degarelix (95% CI: 85.9-94.5) and 85.9% for leuprolide (95% CI: 79.9-90.2). The probability of completing the study without dying by day 364 was 97.4% (95% CI: 93.8-98.9) for degarelix versus 95.1% (95% CI: 90.7-97.4) for leuprolide.

In patients with baseline PSA >20.0 ng/mL, risk of PSA recurrence was lower for patients receiving degarelix compared with leuprolide (p=0.04). The risk of PSA recurrence was comparable in patients with baseline PSA >50.0 ng/mL (p=0.10).

At day 3 of treatment, the degarelix groupachieved a 90% decrease in median testosterone levels compared with a 65% increase in the leuprolide group. Degarelix was as effective as leuprolide in suppressing testosterone levels from day 28 to the end of the study, with 97.2% of the degarelix patients maintaining medical castrate levels compared with 96.4% of those receiving leuprolide.