Bayer relinquishes OTC rights to R-ketoprofen.

MARLBOROUGH, Mass.--(BUSINESS WIRE)--Dec. 4, 1995--Sepracor Inc. (NASDAQ: SEPR), today announced that Bayer Corporation's Consumer Care Division, which is responsible for its over-the-counter products, has decided not to proceed with the over-the-counter R-ketoprofen project. Sepracor will continue to pursue opportunities in the prescription market.

This action followed the completion of several clinical trials involving more than 250 patients, which demonstrated comparable analgesic efficacy to acetaminophen and reduced gastro-intestinal (GI) side-effects compared with racemic ketoprofen. Specifically, the study reported the following, as outlined by Bayer in a study report to Sepracor:

Efficacy Study, using the dental pain model comparing single doses of 25mg and 100mg R-ketoprofen, 1000mg acetaminophen, and placebo. R-ketoprofen 25mg did not separate from placebo, while both R-ketoprofen 100mg and acetaminophen 1000mg showed evidence of analgesic efficacy when compared with placebo. GI Endoscopic Study, comparing R-ketoprofen 100mg, racemic ketoprofen 100mg, acetaminophen 1000mg, and placebo in twice a day over 2 1/2 days. Results showed R-ketoprofen induced significantly fewer lesions than racemic ketoprofen, indicating a relatively safer gastro-intestinal profile. However, acetaminophen and placebo, which were not significantly different from one another, showed fewer gastrointestinal side-effects than either of the ketoprofens.

"While we realize that this product does not fit Bayer's OTC strategy, in view of the results of this efficacy study, Sepracor intends to pursue opportunities for R-ketoprofen as a prescription pain drug." said Timothy J. Barberich, President and Chief Executive Officer.

Sepracor licensed OTC R-ketoprofen in late 1992 to Sterling Winthrop Inc.'s OTC division, a leading global marketer of over-the-counter acetaminophen. Sepracor retained worldwide Rx rights to the product and was issued a US patent in July 1994. Sterling's OTC business was subsequently sold to SmithKline Beecham and Bayer in late 1994. Bayer's Consumer Care Division recently announced marketing clearance for Actron., racemic ketoprofen, as an OTC product.

Sepracor develops Improved Chemical Entities (ICEs ), which are improved versions of existing, widely-sold drugs. -0-

Actron is a registered trademark of Bayer Corporation.

CONTACT: David P. Southwell

Chief Financial Officer

Sepracor Inc.

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Jean M. Devine

Director, Investor Relations 

Sepracor Inc.

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