Positive Test Results for Insomnia Medication

San Diego, CA - Feb. 15, 2001

Neurocrine Biosciences, Inc. announced additional positive results from its ongoing clinical program with NBI-34060 for insomnia.

In a randomized, double-blind, placebo-controlled clinical study with multiple doses of NBI-34060 conducted in young adults and elderly subjects, results demonstrate that NBI-34060 works as a sedative-hypnotic with no major differences in the pharmacokinetics (the process by which a drug is absorbed, distributed, metabolized, and eliminated by the body) for maximum plasma levels or total drug exposure between young adults and elderly subjects.

Also, there were no changes between these patient populations in the accumulation of NBI-34060 after four consecutive nightly doses. Safety evaluation and subjective measures of next day residual effect confirmed that the drug was well tolerated in both groups with the expected sedation during the night, and with no hangover or residual carry over next-day effect. Existing sedative hypnotics demonstrate higher drug levels in elderly patients, indicative of a slower drug clearance, leading to the possibility of increased next day adverse effects.

"The elderly population, which represents a large portion of the insomnia market, would benefit greatly from a novel therapeutic. NBI-34060 continues to demonstrate clinical benefit with a rapid onset of action and an improved safety profile over existing sedative hypnotics," said Gary A. Lyons, CEO and President of Neurocrine Biosciences. "These encouraging results further support Neurocrine's differentiation strategy for NBI-34060 over currently marketed therapeutics for insomnia."

The study compared the pharmacokinetics of NBI-34060 administered to elderly and young adult subjects and assessed the pharmacodynamics (the study of the action or effects of drugs on living organisms), safety and tolerability of NBI-34060 in both patient populations. A total of 25 healthy male and female subjects were randomized, including 13 subjects aged 65 to 79 years (elderly) and 12 subjects aged 18 to 45 years (young adults). For both elderly and young adult subjects, NBI-34060 was rapidly absorbed and eliminated.

In the clinical trial, pharmacodynamic parameters were assessed by a morning sleep questionnaire. These parameters included subjective assessments of latency to sleep onset (LSO), total sleep time (TST) and sleep quality. Both young adult and elderly subjects reported a more rapid sleep onset than placebo subjects and all NBI-34060 subjects reported a longer total sleep time and a shorter total time awake than placebo subjects after all nights of dosing.

These findings were particularly true for Nights 1 and 4 when subjects were frequently disturbed for pharmacokinetic (PK) blood sampling. On those nights, there was a 77% and 43% improvement in the time it took for subjects to fall asleep for elderly and young adult subjects, respectively and an approximately 180% improvement for both groups in the total time that subjects reported they were asleep with respect to placebo. Additionally, in subjective analyses over all nights of dosing, the NBI-34060 subjects, both young adult and elderly, responded positively on sleep quality.

"The study provides additional support to the findings in more than 500 subjects already studied, that NBI-34060 demonstrates the qualities of an effective sedative hypnotic not only in inducing a rapid sleep onset but also in maintaining sleep, which in this study is particularly evident in elderly subjects during nights when subjects were awakened frequently for PK blood sampling," said Bruce Campbell, Ph.D., Senior Vice President of Development for Neurocrine Biosciences. "Further, this is accomplished with no next day residual effects relative to placebo and patients experienced a positive sleep quality. Additional studies are ongoing this year to define the optimal doses for pivotal Phase III studies expected to commence later this year."

Neurocrine Biosciences is a leading neuroscience company focused on the discovery and development of novel therapeutics for neuropsychiatric, neuroinflammatory and neurodegenerative diseases and disorders. The Company's neuroscience, endocrine and immunology disciplines provide a unique biological understanding of the molecular interaction between central nervous, immune and endocrine systems for the development of therapeutic interventions for anxiety, depression, insomnia, stroke, malignant brain tumors, multiple sclerosis, obesity and diabetes.