The sustained release of LH X RH agonist from LH X RH agonist-polymer composite in patients with prostatic cancer.

Luteinizing hormone-releasing hormone (LH X RH) agonist can be administered daily to patients with prostatic cancer with resulting clinical efficacy. A sustained drug release formulation of an LH X RH agonist, (D-Leu6)-des Gly-NH2(10)-LH X RH ethylamide (leuprolide)-vinyl polymer composite, was prepared by means of radiation-induced polymerization under a supercooled state. The sustained release of leuprolide from subcutaneously implanted leuprolide-vinyl polymer composite (14 mm in diameter and 4 mm in thickness) was obtained over a period of several months in five patients with prostatic cancer. Serum testosterone levels began to decrease on the tenth day, fell below 1 ng/ml after three weeks of implantation, and thereafter remained at the castration level until removal of the polymer composite. Clinical improvement was associated with serum hormonal changes, and support this as a novel and superior method of administration of LH X RH agonist.