Neurocrine Biosciences Initiates Phase III Clinical Trial For NBI-34060 in Chronic (Primary) Insomnia

San Diego, CA - November 16, 2001

Neurocrine Biosciences, Inc. today announced that it has initiated the first pivotal Phase III clinical trial of NBI-34060 in approximately 500 patients with chronic (primary) insomnia. The Phase III clinical trial is a randomized, double blind, parallel-group, multi-center study to evaluate the safety of two doses of NBI-34060 Immediate Release (IR) for the long-term treatment of chronic (primary) insomnia in adults. The trial will be conducted in approximately 40 medical sites in the United States and Europe.

"This trial is a major turning point for Neurocrine as we begin our first Phase III program in the history of the Company," said Gary A. Lyons, President and CEO of Neurocrine Biosciences.

"Two additional pivotal Phase III trials with NBI-34060-IR are planned to initiate shortly. We are implementing an aggressive Phase III clinical evaluation of NBI-34060 to support registration of this new sedative hypnotic for short-term and long-term treatment of insomnia," said Henry Pan, M.D. Ph.D, Executive Vice President of Clinical Development and Chief Medical Officer for Neurocrine Biosciences.

Background on NBI-34060 for Insomnia

NBI-34060 is a non-benzodiazepine that acts on a specific site of the GABA-A receptor. It is through this same mechanism that the non-benzodiazepine therapeutics currently on the market produce their sleep-promoting effects.

Insomnia is a prevalent neurological disorder in the United States, with about one-half of the adult population reporting trouble sleeping a few nights per week or more, according to the National Sleep Foundation (NSF). Approximately 29% of the adult population reports that they experience insomnia every night or almost every night. Despite this widespread prevalence, insomnia remains a disorder with high unmet medical needs, including the ability to maintain sleep throughout the night without next-day residual effects.

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, malignant brain tumors and peripheral cancers, diabetes, multiple sclerosis, irritable bowel syndrome, eating disorders, pain, stroke, and certain female health disorders. Neurocrine Biosciences, Inc. news releases are available through the Company's website via the Internet at www.neurocrine.com.

Read about Results of Phase II.