Sepracor Announces ESTORRA™ as Brand Name for New Insomnia Drug

Marlborough, MA - July 16, 2001

Sepracor Inc. announced that it has adopted the brand name ESTORRA™ for its drug candidate esopiclone (formerly (S)-zopiclone), a non-benzodiazepine compound, for the treatment of insomnia.

Sepracor is currently completing Phase III clinical studies for ESTORRA, and preparation of the New Drug Application has begun. In Sepracor's successfully completed large-scale efficacy study in transient insomnia, the data demonstrated that the planned study endpoints of onset of action and duration of activity were achieved. All study endpoints were clinically relevant and statistically significant compared to placebo, and ESTORRA was well tolerated.

"ESTORRA should provide an important therapeutic advance and offer a differentiated new treatment option to physicians and their insomnia patients," stated Paul D. Rubin, M.D., Executive Vice President, Drug Development and Research at Sepracor Inc.

According to the National Sleep Foundation, sleep disorders affect approximately 85 million people in the United States. The U.S. market for prescription sleep products is approaching $1 billion and growing at a rate of 25 percent per year, according to IMS Health information. Insomnia may be caused by a number of factors including stress, anxiety, environmental temperatures, change in the surrounding environment, sleep and wake schedule problems such as those due to jet lag, and medication side effects.

Sepracor Inc. is a research-based pharmaceutical company dedicated to treating and preventing human disease through the discovery, development, and commercialization of innovative pharmaceutical products that are directed toward serving unmet medical needs. Sepracor's drug development program has yielded an extensive portfolio of pharmaceutical candidates that are focused on the treatment of respiratory, urological, and central nervous system disorders. Sepracor's corporate headquarters are located in Marlborough, Massachusetts.