The Western Section of the American Urological Association.

A new six-month subcutaneous (SC) depot of leuprolide acetate (Eligard®, Atrix Laboratories, Inc.), a synthetic luteinizing hormone–releasing hormone (LH-RH) agonist, consistently produced and maintained safe and effective serum testosterone suppression. Total serum testosterone concentrations were well below the medical castrate level of less than 50 ng/dl in adult men with prostate cancer. Because treatment strategies to increase symptom-free survival in patients with advanced disease focus on testosterone suppression to ameliorate symptoms and control disease, a multicenter, open-label study was designed to assess the safety, efficacy, and pharmacokinetics of leuprolide acetate. A total of 111 patients received two SC injections of leuprolide depot 45 mg at 0 and six months over a 12-month period. Safety and efficacy, as measured by testosterone suppression and prostate-specific antigen (PSA) levels, were evaluated. Of the 111 patients, 103 (93%) completed the 12-month study. Overall, mean and median times to castrate suppression were 21.2 and 21 days, respectively. At the completion of the study, 99% of patients had testosterone concentrations that were below castrate levels (12.3 ± 2.1 ng/dl). Mean PSA levels decreased by 97%, from 39.8 ± 21.5 ng/ml at baseline, to 1.2 ± 0.3 ng/ml at 12 months. There were no clinically significant flare reactions. The most common treatment-related adverse drug event (ADE) was mild-to-moderate hot flashes.