Release Details

Immediate Release Formulation Demonstrated Statistically Significant Improvements in Sleep Initiation and Sleep Quality

SAN DIEGO, Feb. 18 /PRNewswire-FirstCall/ -- Neurocrine Biosciences, Inc. (Nasdaq: NBIX) today announced positive results from its Phase III clinical trial with two doses (5 mg and 10 mg) of the immediate release formulation of indiplon, achieving statistically significant results in elderly patients with chronic insomnia. Results of the primary endpoint for this study, Latency to Sleep Onset (LSO) or the amount of time it took patients to fall asleep, as measured by patient self reported outcomes was statistically significant for both doses (p<0.02 at 5 mg and p<0.005 at 10 mg) as compared to placebo. For LSO, the time to sleep was shortened by more than 27 minutes for both indiplon doses, more than a 40% reduction from baseline. Secondary endpoints, including patient self reported Total Sleep Time (sTST), Wake After Sleep Onset (sWASO), and Number of Awakenings After Sleep Onset (sNAASO) were also statistically significant as compared to placebo. Sleep quality was significantly improved (p<0.005) at both dose levels as compared to placebo. Results confirmed that elderly patients with chronic insomnia who took indiplon fell asleep more rapidly and stayed asleep longer with fewer awakenings and reported improved sleep quality. Additionally, indiplon immediate release was well tolerated and there were no treatment related serious adverse events reported in the study.

"We are pleased with the first Phase III clinical trial results demonstrating that indiplon immediate release formulation is safe and effective in treating elderly patients who experience many different symptoms of chronic insomnia," said Henry Pan, Executive Vice President and Chief Medical Officer for Neurocrine Biosciences. "We are confident that these data will demonstrate the potential of indiplon to meet the needs of many populations such as the elderly."

"Indiplon has now consistently demonstrated that it helps patients fall asleep faster, stay asleep longer and improves their quality of sleep with no important safety issues. Indiplon (immediate release) formulation could provide a treatment option targeting chronic insomnia, a prevalent and growing problem among elderly patients," said Dr. Thomas Roth, Chief, Division Head, Sleep Disorders and Research Center, Henry Ford Hospital.

Study Design

The study was a Phase III randomized, placebo-controlled, double-blind, parallel-group, outpatient, multi-center study to assess the efficacy and safety of two dose levels of indiplon immediate release (5 mg and 10 mg) in 360 elderly patients with chronic insomnia. The trial was conducted in approximately 50 centers in North America. Patients were evaluated over a two week treatment period, and were eligible to continue in a six month open-label extension of this trial.

About Indiplon

Indiplon is a unique non-benzodiazapine agent that acts on a specific site of the GABA-A receptor. Indiplon has been shown to bind selectively to the specific subtype of GABA-A receptors within the brain believed to be responsible for promoting sleep. There are two formulations of indiplon, immediate release and modified release. Both formulations are being studied in clinical trials to address different types of sleep problems

About Neurocrine Biosciences

Neurocrine is conducting one of the most comprehensive clinical programs in insomnia to address the multiple needs of younger and older adult patients with insomnia such as sleep initiation, sleep maintenance, and the need for chronic usage. Neurocrine has initiated and is completing all of its Phase III safety and efficacy trials to support a New Drug Application (NDA) for the two formulations, expected in the first half of 2004 for indiplon for multiple insomnia indications. The Phase III program alone will have data from approximately 5,000 patients with different types of insomnia. Indiplon was licensed from DOV Pharmaceutical in 1998.

Insomnia is a prevalent condition in the United States, with nearly one-half 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 the Company's indiplon clinical development 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 or Phase III clinical trials may fail to demonstrate that indiplon is safe and effective in treating humans; risk that the Company may not complete indiplon Phase III clinical trials on the Company's projected timelines for various reasons, including the possibility that patient recruitment may be slower than expected; 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 Form 10-K for the year ended December 31, 2002, the Company's most recent report on Form 10-Q and the Company's final prospectus supplement and accompanying prospectus relating to its recent offering. Neurocrine undertakes no obligation to update the statements contained in this press release after the date hereof.

SOURCE Neurocrine Biosciences, Inc.