Pharmacological profile of a new, potent, and long-acting gonadotropin-releasing hormone antagonist: degarelix.
We describe the pharmacological profile in rats and monkeys of degarelix (FE200486), a member of a new class of long-acting gonadotropin-releasing hormone (GnRH) antagonists. At single subcutaneous injections of 0.3 to 10 microg/kg in rats, degarelix produced a dose-dependent suppression of the pituitary-gonadal axis as revealed by the decrease in plasma luteinizing hormone (LH) and testosterone levels. Duration of LH suppression increased with the dose: in the rat, significant suppression of LH lasted 1, 2, and 7 days after a single subcutaneous injection of degarelix at 12.5, 50, or 200 microg/kg, respectively. Degarelix fully suppressed plasma LH and testosterone levels in the castrated and intact rats as well as in the ovariectomized rhesus monkey for more than 40 days after a single 2-mg/kg subcutaneous injection. In comparative experiments, degarelix showed a longer duration of action than the recently developed GnRH antagonists abarelix, ganirelix, cetrorelix, and azaline B. The in vivo mechanism of action of degarelix was consistent with competitive antagonism, and the prolonged action of degarelix was paralleled by continued presence of radioimmunoassayable degarelix in the general circulation. In contrast to cetrorelix and similarly to ganirelix and abarelix, degarelix had only weak histamine-releasing properties in vitro. These results demonstrate that the unique and favorable pharmacological properties of degarelix make it an ideal candidate for the management of sex steroid-dependent pathologies requiring long-term inhibition of the gonadotropic axis.
Broqua
Pierre
P
Ferring Research, Division of Biology of Growth and Reproduction, University of Geneva Medical School, Geneva, Switzerland. pierre.broqua@ferring-research.co.uk
Riviere
Pierre J-M
PJ
Conn
P Michael
PM
Rivier
Jean E
JE
Aubert
Michel L
ML
Junien
Jean-Louis
JL
D000818:Animals; D005260:Female; D012739:Gonadal Steroid Hormones / Q000502:physiology; D007987:Gonadotropin-Releasing Hormone / Q000037:antagonists & inhibitors*; D006066:Gonads / Q000187:drug effects / Q000502:physiology; D006636:Histamine Release / Q000187:drug effects; D006727:Hormone Antagonists / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000494:pharmacology*; D007275:Injections, Intravenous; D007279:Injections, Subcutaneous; D007986:Luteinizing Hormone / Q000097:blood; D008253:Macaca mulatta; D008297:Male; D008407:Mast Cells / Q000187:drug effects / Q000378:metabolism; D009842:Oligopeptides / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000494:pharmacology*; D009919:Orchiectomy; D010902:Pituitary Gland / Q000187:drug effects / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013739:Testosterone / Q000097:blood
D012739:Gonadal Steroid Hormones; D006727:Hormone Antagonists; D009842:Oligopeptides; C431566:acetyl-2-naphthylalanyl-3-chlorophenylalanyl-1-oxohexadecyl-seryl-4-aminophenylalanyl(hydroorotyl)-4-aminophenylalanyl(carbamoyl)-leucyl-ILys-prolyl-alaninamide; D007987:Gonadotropin-Releasing Hormone; D013739:Testosterone; D007986:Luteinizing Hormone