Arformoterol Study Data Presented at European Respiratory Society Annual Congress.

MARLBOROUGH, Mass. -- Sepracor Inc. (Nasdaq: SEPR) today announced that it presented a poster of pooled data from Phase III trials of arformoterol tartrate inhalation solution at the 16th Annual Congress of the European Respiratory Society (ERS) in Munich, Germany.

Arformoterol tartrate inhalation solution is a long-acting beta-agonist formulation proposed for long-term maintenance treatment of chronic obstructive pulmonary disease (COPD), including chronic bronchitis and emphysema. A New Drug Application (NDA) for arformoterol tartrate inhalation solution is currently under U.S. Food and Drug Administration (FDA) review. The Prescription Drug User Fee Act (PDUFA) date for arformoterol is October 12, 2006. A PDUFA date is the date by which the FDA is expected to review and act on an NDA submission.

Arformoterol, a single isomer of formoterol, is the first long-acting bronchodilator to be developed in an inhalation solution for use with a nebulizer, which is a machine that converts liquid medication into a fine mist that is inhaled through a mouthpiece or mask; other long-acting bronchodilators currently available in the U.S. are formulated in dry-powder inhalers.

Efficacy of Nebulized Arformoterol, a Long-Acting Beta2-Adrenergic Bronchodilator, in Patients with COPD: Results from Two Pooled Phase III Trials

Results of two identically-designed, double-blind, randomized, placebo-controlled, multicenter studies that included 1,456 adult patients with COPD were presented. The studies evaluated airway function improvement with arformoterol and salmeterol (SEREVENT(R) metered-dose inhaler) compared with placebo over a period of 12 weeks in patients with COPD.

Patients treated with nebulized arformoterol demonstrated clinically meaningful and statistically significant improvement in airway function, as compared to placebo, throughout the dosing interval, over the entire 12-week duration of the trials. The improvement in FEV(1) continued to be observed even at the end (trough) of the dosing interval. The trial data showed that a substantial proportion of arformoterol-treated patients attained a greater or equal to 10% post-dose improvement in FEV(1) after 12 weeks of daily dosing (78.4-86.6% arformoterol; 56.1% salmeterol; and 43.9% placebo). The median time to achieve a 10% response at Week 12 was 3-13 minutes for patients treated with nebulized arformoterol and 142 minutes for patients administered salmeterol.

FEV(1) is the volume exhaled during the first second of a forced expiratory maneuver started after a complete and full inhalation. FEV(1) is a well standardized and frequently used index for assessing airway obstruction in COPD.

"These data suggest that arformoterol provides sustained and rapid bronchodilation for patients with COPD who need a nebulized long-term maintenance treatment," stated Nicola Hanania, M.D., Associate Professor of Medicine, Baylor College of Medicine, Houston. "I'm excited that a new nebulized treatment option for patients with COPD is currently under FDA review. For many patients with COPD, nebulization can provide a very effective delivery system."

Arformoterol was well tolerated in these studies, with COPD exacerbations (periodic worsening of breathing symptoms) occurring with similar or lower frequency than were observed in the placebo and salmeterol treatment groups.

In addition to the aforementioned poster presentation, three other arformoterol posters were presented. They included: Nebulized Arformoterol in COPD - Safety Results from Two Pooled Phase III Trials; Exposure-Response Relationship for Nebulized Arformoterol in Subjects with COPD; and Population Pharmacokinetics of Nebulized Arformoterol in Subjects with COPD.

About COPD

According to the National Center for Health Statistics, COPD is the fourth leading cause of death in the U.S., and in 2003, an estimated 11 million adults in the U.S. had COPD. Approximately 24 million adults have evidence of impaired lung function, which may indicate that COPD is under-diagnosed, according to the National Heart, Lung, and Blood Institute (NHLBI). COPD is a slowly progressive disease of the airways that is characterized by a gradual loss of lung function. According to the NHLBI, COPD includes chronic bronchitis, chronic obstructive bronchitis and emphysema, or combinations of these conditions. Bronchodilator medications are used to improve airflow and COPD symptoms, and to reduce the occurrence and/or severity of exacerbations in patients affected by COPD.

About Sepracor

Sepracor Inc. is a research-based pharmaceutical company dedicated to treating and preventing human disease by discovering, developing and commercializing innovative pharmaceutical products that are directed toward serving unmet medical needs. Sepracor's drug development program has yielded a portfolio of pharmaceutical products and candidates with a focus on respiratory and central nervous system disorders. Sepracor's corporate headquarters are located in Marlborough, Massachusetts.

Forward Looking Statement

This news release contains forward-looking statements that involve risks and uncertainties, including statements with respect to safety, efficacy and potential benefits of arformoterol, the date by which the FDA is expected to complete its review of the arformoterol NDA and successful development, regulatory approval and expected commercial launch of arformoterol. Among the factors that could cause actual results to differ materially from those indicated by such forward-looking statements are: Sepracor's ability to fund further clinical trials; results of further clinical trials; the timing and outcome of the FDA's review of the arformoterol NDA and other regulatory filings; and certain other factors that are detailed in the company's quarterly report on Form 10-Q for the quarter ended June 30, 2006 filed with the Securities and Exchange Commission.

In addition, the statements in this press release represent Sepracor's expectations and beliefs as of the date of this press release. Sepracor anticipates that subsequent events and developments may cause these expectations and beliefs to change. However, while Sepracor may elect to update these forward-looking statements at some point in the future, it specifically disclaims any obligation to do so. These forward-looking statements should not be relied upon as representing Sepracor's expectations or beliefs as of any date subsequent to the date of this press release.

Serevent is a registered trademark of Glaxo Group Limited Corporation.

For a copy of this release or any recent release, visit Sepracor's web site at www.sepracor.com.