Release Details

SAN DIEGO, June 24 /PRNewswire-FirstCall/ -- Neurocrine Biosciences, Inc. (Nasdaq: NBIX) announced today positive results from the Company's Phase I clinical trial with its proprietary, orally active small molecule Gonadotropin-Releasing Hormone (GnRH) receptor antagonist to evaluate the safety, pharmacokinetics (PK), and pharmacodynamics (PD) of multiple dosing of NBI-42902 in healthy pre-menopausal women. Results demonstrated that NBI-42902 was safe and well tolerated.

Eighteen healthy pre-menopausal women participated in this randomized, double-blind, placebo-controlled, parallel group, multiple-dose regimen study. The subjects were assigned to three groups of six with each subject receiving daily doses of either placebo, 75 mg of NBI-42902 once a day or 37.5 mg of NBI-42902 twice a day for seven consecutive days.

Preliminary pharmacokinetic data demonstrated that NBI-42902 was absorbed rapidly after oral administration. The systemic exposure as measured by AUC and Cmax was proportional to the total dose given either once-a-day or twice-a-day and was similar between Day One and Day Seven of dosing indicating no evidence of accumulation, enzyme induction or inhibition. Initial pharmacodynamic evaluation indicated suppression of luteinizing hormone (LH) and follicle stimulating hormone (FSH) as expected based on data from a previous study with the compound in post-menopausal women. Furthermore, gonadal suppression was achieved resulting in suppression of estrogen to levels anticipated to be therapeutic. NBI-42902 was well tolerated by all subjects with no discontinuations or serious adverse events. These results indicate that an orally active GnRH antagonist may be useful in suppression of estrogen levels in the treatment of hormone dependent diseases in pre-menopausal women.

GnRH is a neuroendocrine peptide which stimulates the secretion of the pituitary LH, which in turn stimulates the production of estrogen by the ovary or testosterone by the testis. The most widely prescribed drugs modulating at the GnRH receptor are peptide agonists such as Lupron(R) and Zoladex(R) with estimated combined sales in excess of $2.5 billion worldwide. These compounds are administered as injectable depots which act by first stimulating then eventually inhibiting the secretion of pituitary LH and consequently, estrogen or testosterone production. These drugs have proven clinically useful in treating hormone dependent diseases such as endometriosis, uterine fibroids, prostate cancer and breast cancer, as well as being used for assisted- reproductive therapy. NBI-42902 discovered and developed within Neurocrine, is a specific highly potent non-peptide, orally active antagonist of the GnRH receptor. This compound inhibits pituitary LH secretion directly, potentially preventing the several week delay and flare associated with agonist therapy. Neurocrine believes that orally active, non-peptide GnRH antagonists should provide a more rapid onset of action, increased dosing flexibility and greater patient acceptability over currently available treatments.

Neurocrine Biosciences, Inc. is a product-based biopharmaceutical company focused on neurological and endocrine diseases and disorders. Our product candidates address some of the largest pharmaceutical markets in the world including insomnia, anxiety, depression, diabetes, multiple sclerosis, irritable bowel syndrome, eating disorders, pain, autoimmunity and certain female and male health disorders. Neurocrine Biosciences, Inc. news releases are available through the Company's website via the Internet at http://www.neurocrine.com .

In addition to historical facts, this press release may contain forward- looking statements that involve a number of risks and uncertainties. Among the factors that could cause actual results to differ materially from those indicated in the forward looking statements are risks and uncertainties associated with Neurocrine's business and finances and research programs in general including, but not limited to, risk and uncertainties associated with, or arising out of, drug discovery, pre-clinical and clinical development of products and specifically, risk that Neurocrine's current lead GnRH antagonist compound may prove unsuitable for continued clinical development; risk that Neurocrine's GnRH antagonist program may not generate any additional development candidates that lead to late stage clinical testing or commercial products; risks relating to Neurocrine's dependence upon strategic partners for certain commercialization activities; uncertainties relating to patent protection for GnRH antagonists identified by Neurocrine and intellectual property rights of third parties in the GnRH field; impact of competitive products and technological changes; availability of capital and cost of capital; and other material risks. A more complete description of these can be found in the Company's Form 10K for December 31, 2002 and the Company's most recent report on Form 10Q. Neurocrine undertakes no obligation to update the statements contained in this press release after the date hereof.

SOURCE Neurocrine Biosciences, Inc.