An evaluation of the pharmacokinetics and pharmacodynamics of the histrelin implant for the palliative treatment of prostate cancer.

Seventeen patients with advanced prostate cancer were studied to evaluate the pharmacokinetics and pharmacodynamics of a hydrogel implant designed to deliver histrelin at a constant rate (50 microg/d) for 1 year. Serum histrelin levels were collected during the 52-week implantation period and after a second implant. Testosterone suppression was the primary pharmacodynamic endpoint, with treatment success defined as serum testosterone less than 50 ng/dL.