Release Details

Neurocrine Is on Track to File NDAs for Both Indiplon IR and MR

SAN DIEGO, Sept. 9 /PRNewswire-FirstCall/ -- Neurocrine Biosciences, Inc. (Nasdaq: NBIX) today announced positive efficacy and safety results from the Company's Phase III clinical trial with indiplon modified release 15 mg in 229 elderly patients with chronic insomnia. Neurocrine is on track to submit its two New Drug Applications (NDAs) for the immediate and modified release formulations of indiplon beginning in October 2004. The two NDAs will include data from Phase I, II and III clinical trials in over 7400 patients and subjects with over 300,000 patient exposures in one of the most comprehensive clinical programs in insomnia. To date the indiplon clinical program has demonstrated indiplon to be a safe and efficacious treatment option to address the multiple sleep needs of younger and older adult patients such as: falling asleep faster, reducing the number and duration of awakenings, and improving sleep quality. Clinical trials have also demonstrated that indiplon can help patients improve their sleep over a sustained period of time.

Efficacy and Safety Results with Indiplon-MR in Elderly Patients

Efficacy results with the 15 mg dose of indiplon modified release tablets demonstrated a highly statistically significant improvement on the primary endpoint of patient reported Total Sleep Time (sTST) as compared to placebo (p0.0001) at all time points during the two week duration of the trial. Improvements in secondary patient reported sleep maintenance endpoints were also statistically significant (p0.0001) for all parameters and at all time points during the two week duration of the trial. These include Wake After Sleep Onset (sWASO), Total Wake Time (sTWT) and Number of Awakenings After Sleep Onset (sNAASO). Indiplon modified release tablets also demonstrated a highly statistically significant improvement in sleep initiation assessed by patient reported Latency to Sleep Onset (LSO) as compared to placebo (p0.0001) at all time points during the 2 week duration of the trial. Patient reported Sleep Quality also showed a highly statistically significant improvement over placebo (p0.0001) at all time points during the 2 week duration of the study. Improvement was also demonstrated in next day functioning and next day alertness assessed by patient self completed scales.

Safety results were similar to what has previously been observed in other indiplon modified release and immediate release studies. Patient reported Global Impression (PGI), a 5 item scale assessing the overall effect of the study drug on sleep, time to fall asleep, amount and quality of the sleep, and the strength of the medication also showed a highly statistically significant improvement over placebo (p0.0001). The Investigator reported Global Rating for Severity of insomnia and Change (IGR-S; IGR-C) scales were both highly statistically significant versus placebo in favor of indiplon (p0.0001).

Study Design

The study was a randomized, double-blind, placebo-controlled, parallel- group, multi-center, out-patient Phase III clinical trial conducted in 229 elderly patients with sleep maintenance difficulties. The study was conducted at 44 sleep centers in the U.S. Patients received nightly administration of 15 mg of indiplon modified release tablets or placebo over a two-week period.

"We are very pleased with this study, we couldn't have hoped for a better result in all safety and efficacy parameters. As expected, the 15 mg dose showed significant improvement in sleep maintenance at every primary and secondary endpoint, as well as in next day functioning and alertness. Based on these results Neurocrine expects to submit an NDA for indiplon modified release that will include the 15 mg dose. We believe the registration of indiplon modified release and immediate release will provide a broad spectrum of treatment for all sleep disorders including sleep initiation, sleep maintenance, middle of the night awakening and long term chronic usage," said Dr. Henry Pan, Executive Vice President and Chief Medical Officer for Neurocrine Biosciences.

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. Two formulations of indiplon, immediate release capsules and modified release tablets, are being evaluated in clinical trials 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 approximately 40 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, but not limited to, risk 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, 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 and most recent 10-Q filed for the second quarter ended, June 30, 2004. Neurocrine undertakes no obligation to update the statements contained in this press release after the date hereof.

SOURCE Neurocrine Biosciences, Inc.