Safety and efficacy of an implantable leuprolide delivery system in patients with advanced prostate cancer

Purpose: We evaluated the pharmacokinetics, safety and efficacy of the impl antable Viadur dagger leuprolide delivery system during 12 months in patien ts with advanced prostate cancer. Materials and Methods: Our open label, multicenter, dose ranging study was done in 2 phases. The treatment phase was a stratified, randomized, paralle l evaluation of the safety and efficacy of 1 or 2 implants. The safety exte nsion phase assessed the long-term safety and efficacy of 1 implant. Implan t insertion and removal, pharmacokinetic profile and patient satisfaction w ere also evaluated. The primary efficacy parameter was testosterone suppres sion for 12 months but luteinizing hormone and prostate specific antigen we re also evaluated. Results: Of the 51 patients 27 received 1 and 24 received 2 implants, of wh om 49 completed the 12-month treatment phase. Steady serum leuprolide conce ntration was maintained from day 3 through the remainder of the 12-month tr eatment phase and for 2 months after reimplantation. Implantation and reimp lantation were well tolerated and acceptable to physicians and patients. Te stosterone suppression to the castrate range was 100% in each group. At; 12 months mean prostate specific antigen decreased from a baseline of approxi mately 84% and 91% in groups 1 and 2, respectively. Serious adverse events during the study period in 15 patients were not attributable to treatment. Conclusions: The implantable leuprolide delivery system provides effective suppression of testosterone in patients with advanced prostate cancer.