Release Details

Data Presented at the American Psychiatric Association (APA) Meeting

NEW YORK, May 6 /PRNewswire-FirstCall/ -- Neurocrine Biosciences, Inc. (Nasdaq: NBIX) announced today results from two Phase I studies demonstrating that indiplon modified release does not effect respiratory functioning in healthy subjects or those with mild-to-moderate chronic obstructive pulmonary disease (COPD). These results were presented today at the 157th annual meeting of the American Psychiatric Association (APA) in New York City.

The first study presented today was conducted in 12 healthy male volunteers in a double-blind crossover design with indiplon modified release 30 mg, codeine sulfate 60 mg (as a positive control), or placebo. Indiplon modified release demonstrated no statistically or clinically significant effects on respiratory function as compared with placebo in response to carbon dioxide (CO2) challenge, whereas following treatment with codeine sulfate 60 mg, respiratory suppression was observed in response to CO2 challenge at all post-dose time points. The 30 mg dose of indiplon modified release was safe and well tolerated.

The second study presented today evaluated the potential respiratory depressant effects, safety and tolerability of a 20 mg dose of indiplon modified release in a double-blind two-way crossover study in 18 patients with mild-to-moderate COPD. Primary outcomes consisted of the measurements of arterial oxygen saturation and the respiratory disturbance index of the effects of sleep apnea on total sleep time. Sleep quality was assessed using a subjective sleep quality questionnaire. In patients with mild to moderate COPD, indiplon modified release 20 mg had no clinically significant effects on respiratory function. Sleep quality was subjectively rated as "very good" or "excellent" by 50 percent of subjects on indiplon versus 17 percent of subjects on placebo.

"Effects of a sedative on respiratory function are often a concern, particularly in treating patients with insomnia. Results from these two studies demonstrate that indiplon modified release was safe and well tolerated and was not associated with any relevant effects on respiratory function in patients with chronic obstructive pulmonary disease," said Dr. Steven Hull, lead author and Medical Director, somniTech Inc.

About Indiplon

Indiplon is a novel GABA-A receptor potentiator with high selectivity for the specific subtype of GABA-A receptors within the brain believed to be responsible for promoting sleep. Two formulations of indiplon, immediate release and modified release, are being developed to address different types of sleep problems. Indiplon was licensed from DOV Pharmaceutical in 1998.

Insomnia is a prevalent condition in the United States, with 58 percent of the adult population reporting trouble sleeping a few nights per week or more, according to the National Sleep Foundation's (NSF) Sleep in America Poll 2002. Approximately 35 percent of the adult population reports that they have experienced insomnia every night or almost every night within the past year. Insomnia remains a disorder with high unmet medical needs, including prolonged awakenings during the night with difficulty falling back to sleep.

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, certain female and male disorders, anxiety, depression, diabetes, multiple sclerosis, irritable bowel syndrome, eating disorders, pain, and autoimmunity. 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 including risk that the Company's Urocortin and CRF research programs will not lead to clinical candidates, that the GnRH receptor antagonist, D2 receptor agonist and altered peptide ligand clinical candidates will not proceed to later stage clinical trials and risks and uncertainties associated with the Company's indiplon Phase III program and planned regulatory activities. Specifically, the risks and uncertainties the Company faces with respect to its indiplon program include, but are not limited to, risk that indiplon may not successfully proceed through Phase III clinical trials including the risk that Phase III clinical trials may fail to demonstrate that indiplon is safe and effective in treating humans and the risk that additional clinical studies may be required to support filings for regulatory approval; risk that the Company may not complete indiplon Phase III clinical trials on the Company's projected timelines for various reasons, including the risk that the clinical investigators and contract research organizations upon which the Company relies to conduct its clinical programs may not be diligent, careful or timely, and may make mistakes, in the conduct of the programs; risk relating to the Company's dependence on contract manufacturers for clinical drug supply and compliance with regulatory requirements for marketing approval; risk that the Company may not successfully co-ordinate the completion and submission of planned regulatory filings on the Company's projected timelines; risk that the Company may not receive regulatory approval for indiplon or approval may be delayed; risks associated with the Company's dependence on corporate collaborators for commercial manufacturing and marketing and sales activities; uncertainties relating to patent protection and intellectual property rights of third parties; risks and uncertainties relating to competitive products and technological changes that may limit demand for the Company's products; risk that the Company will be unable to raise additional funding required to complete development of all of its product candidates; and the other risks described in the Company's report on Form 10-K for the year ended December 31, 2003. Neurocrine undertakes no obligation to update the statements contained in this press release after the date hereof.

SOURCE Neurocrine Biosciences, Inc.