Release Details

Results Demonstrate Indiplon Significantly Improves Sleep Initiation and Sleep Maintenance

PHILADELPHIA, June 7 /PRNewswire-FirstCall/ -- Neurocrine Biosciences, Inc. (Nasdaq: NBIX) announced today that six studies from Phase I, II and III clinical trials with both formulations of indiplon will be presented at the Associated Professional Sleep Societies (APSS) Meeting, June 5-10, 2004 in Philadelphia, PA. The studies demonstrate that two formulations of indiplon, an immediate release capsule and a modified release tablet, can help patients with insomnia fall asleep faster and stay asleep longer without experiencing next-day residual effects.

"These data being presented further reinforce the robustness of the indiplon clinical program," said Dr. Henry Pan, Executive Vice President and Chief Medical Officer for Neurocrine Biosciences. "The ability to tailor treatment for insomnia patients with the indiplon immediate release and modified release formulations will allow physicians to address different groups of insomnia patients as well as individual patients with changing insomnia problems. The physician has one drug to customize treatment for each patient."

Indiplon Immediate Release

The immediate release formulation has a rapid onset of action, so that when patients awake in the morning, there are minimal hangover or residual effects, even when taken in the middle of the night. Three studies on indiplon immediate release are being presented at APSS, including:

     *  Residual Effects of Middle of the Night Dosing: A Placebo-Controlled
        Crossover Study of Indiplon Immediate Release, Zolpidem, and Zopiclone
        in Healthy Volunteers (Poster presentation on Tuesday, June 8 at
        1:30pm EDT)

     *  Efficacy and Tolerability of Indiplon Immediate Release in the
        Treatment of Transient Insomnia (Poster presentation on Tuesday,
        June 8 at 1:30pm EDT)

     *  Treatment of Primary Insomnia for 5 Weeks (Oral presentation on
        Thursday, June 10 at 8:00am EDT)

    Indiplon Modified Release

The modified release formulation is designed to provide an initial release of indiplon to produce rapid sleep initiation followed by a second gradual release of indiplon to maintain sleep throughout the night. There are three studies on the modified release formulation of indiplon that are being presented at APSS, including:

     *  Assessment of Respiratory Effects of Indiplon Modified Release in a
        CO2 Challenge Model (Poster presentation on Tuesday, June 8 at
        1:30pm EDT)

     *  Safety of Indiplon Modified Release in Patients with Mild to Moderate
        COPD (Poster presentation on Tuesday, June 8 at 1:30pm EDT)

     *  Efficacy of Indiplon Modified Release In Inducing and Maintaining
        Sleep in Patient's with Chronic Sleep Maintenance Insomnia (Poster
        presentation on Tuesday, June 8 at 1:30pm EDT)

    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 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 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, 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, 2003, and the Company's most recent report on Form 10-Q. Neurocrine undertakes no obligation to update the statements contained in this press release after the date hereof.

SOURCE Neurocrine Biosciences, Inc.