Data for XOPENEX(R) Brand of Levalbuterol Presented at American College of Chest Physicians Annual Conference.

MARLBOROUGH, Mass. -- Sepracor Inc. (Nasdaq: SEPR) today announced the presentation of posters of clinical data from studies of XOPENEX HFA([R]) (levalbuterol tartrate) Inhalation Aerosol and XOPENEX([R]) (levalbuterol HCl) Inhalation Solution at CHEST 2006, the annual meeting of the American College of Chest Physicians (ACCP), in Salt Lake City.

Pharmacoeconomic Outcomes of Levalbuterol and Racemic Albuterol in Inpatients Requiring Nebulization (POLARIS)

Results of a randomized, prospective, open-label, multi-center study assessing clinical outcomes based on the number of nebulizations throughout the duration of the hospital stay and cost-effectiveness in hospitalized patients administered either XOPENEX Inhalation Solution (n=241) or racemic albuterol (n=238) by nebulization were presented. Upon admission to the hospital, patients were randomly assigned to treatment with XOPENEX 1.25 mg Q8h (every eight hours) or racemic albuterol administered per routine standing hospital orders, which was usually Q4-6h (every four to six hours). Standing orders with a matching beta-agonist were provided for rescue treatments.

In this study, patients administered XOPENEX Inhalation Solution received fewer total nebulizations during their hospital stay versus patients administered albuterol (median 10 for XOPENEX, 12 for albuterol; p=0.03). No significant differences were observed between the two groups in measures of FEV1, duration of hospital stay, relapse rate, total hospital costs or respiratory costs. The primary pharmacoeconomic analysis was based on costs and Subject General Well-Being (SGWB) and showed an increase of approximately 2 units in SGWB (scale 0-100) when compared with albuterol and that use of XOPENEX was $165 less costly per patient. The results of this study confirmed that less frequent administration of XOPENEX Inhalation Solution maintained comparable efficacy compared with albuterol without increasing the cost of therapy and may be cost effective when compared to use of albuterol. XOPENEX Inhalation Solution was generally well tolerated in this study.

Long-term Safety of Levalbuterol Administered via Metered-Dose Inhaler in Patients with Asthma

Also presented were results of a randomized, open-label, active-controlled, multi-center, parallel-group, safety study in which patients 12 years of age and older with stable asthma were treated four times daily with either XOPENEX HFA (n=496) or PROVENTIL([R]) HFA (albuterol; n=250) over 12 months. In the study, the overall incidence of adverse events (AEs) in the XOPENEX HFA (72%) and PROVENTIL HFA (76.8%) groups was similar. The rate of adverse events with the potential to be related to the specific pharmacologic action of these drugs, including tachycardia, palpitation, chest pain, arrhythmia, hypertension, dyspepsia, nausea, leg cramps, dizziness, insomnia, nervousness, anxiety and tremor, was 13.3% in patients administered XOPENEX HFA, and 18.4% in patients administered PROVENTIL HFA. Asthma-related adverse events were similar between treatment groups: 18.3% for the XOPENEX HFA treatment group and 19.6% for the PROVENTIL HFA treatment group.

Lung function with chronic dosing was also assessed in this study. In patients treated with XOPENEX HFA, the mean percent change in FEV1 (forced expiratory volume in one second) was 18.1% one hour after the first dose, and 16.3% for patients treated with PROVENTIL HFA. At Week 52, the mean percent change in FEV1 was 12.7% for patients treated with XOPENEX HFA and 11.6% for patients treated with PROVENTIL HFA. XOPENEX HFA was generally well tolerated in this study.

An Evaluation of Levalbuterol HFA in the Prevention of Exercise-Induced Bronchospasm

Also presented were the results of a double-blind, randomized, placebo-controlled crossover study of 15 adult mild-to-moderate asthmatic patients with exercise-induced bronchospasm (EIB) who were administered either XOPENEX HFA or placebo pre-exercise to evaluate the ability to prevent EIB. The study evaluated the maximum decrease in FEV1 post-exercise. In the study, patients treated with XOPENEX HFA demonstrated a significantly smaller (p<0.001) decrease in post-exercise FEV1 compared with patients treated with placebo (5.82% decrease for patients treated with XOPENEX HFA and 21.8% decrease for patients administered placebo; p=0.0002). A significantly higher percentage of XOPENEX HFA patients were protected from EIB compared with patients treated with placebo (93.3% for patients treated with XOPENEX HFA compared with 53.3% patients administered placebo; (p=0.0143). XOPENEX HFA was generally well tolerated in this study.

XOPENEX HFA is not indicated for prevention of EIB and this study was not specifically designed to support such an indication.

About XOPENEX HFA Inhalation Aerosol

XOPENEX HFA is a hydrofluoroalkane (HFA) metered-dose inhaler (MDI), which is a portable, hand-held device consisting of a pressurized canister containing medication and a mouthpiece through which the medication is inhaled. XOPENEX HFA is indicated for the treatment or prevention of bronchospasm in adults, adolescents and children 4 years of age and older with reversible obstructive airway disease.

About XOPENEX Inhalation Solution

XOPENEX Inhalation Solution is approved for use in a nebulizer at 0.31 mg and 0.63 mg dosage strengths for treatment of children 6 to 11 years old, and in 0.63 mg and 1.25 mg dosage strengths for patients 12 years of age and older. A nebulizer is a machine that converts liquid medication into a fine mist, which is inhaled through a mask to deeply penetrate into a patient's lungs.

About Asthma

Asthma is a chronic lung disorder characterized by reversible airway obstruction and the pathologic finding of airway inflammation. According to the 2002 National Health Interview Survey conducted by the Centers for Disease Control and Prevention, nearly 31 million Americans have been diagnosed with asthma in their lifetime. It is the most common childhood illness and affects nearly 9 million children in the U.S. under the age of 18. Short-acting bronchodilators are the most-prescribed asthma therapy among primary care physicians and pediatricians in the U.S., according to IMS Health information.

Important Safety Information

XOPENEX HFA and XOPENEX Inhalation Solution are contraindicated in patients with a history of hypersensitivity to levalbuterol, racemic albuterol or any other component of XOPENEX HFA or XOPENEX Inhalation Solution. XOPENEX HFA and XOPENEX Inhalation Solution and other beta-agonists can produce paradoxical bronchospasm, which may be life threatening. If additional adrenergic drugs, including other short-acting sympathomimetic bronchodilators or epinephrine, are to be administered by any route, they should be used with caution to avoid deleterious cardiovascular effects. Due to the cardiovascular side effects associated with beta-agonists, caution is generally recommended for patients with cardiovascular disorders (especially coronary insufficiency, cardiac arrhythmias and hypertension), diabetes, hyperthyroidism, or convulsive disorders. Also, see the complete prescribing information regarding potential drug interactions with beta-blockers, diuretics, digoxin or MAOI and tricyclic antidepressants.

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 the safety, efficacy and potential benefits of XOPENEX HFA Inhalation Aerosol and XOPENEX Inhalation Solution. 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; the results of any further clinical trials; the commercial success of XOPENEX HFA and XOPENEX Inhalation Solution; any changes in the use and/or label of XOPENEX HFA or XOPENEX Inhalation Solution; the pricing of competitive products; the ability of the company to attract and retain qualified personnel; 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.

XOPENEX and XOPENEX HFA are registered trademarks of Sepracor Inc. PROVENTIL is a registered trademark of Schering Corporation.

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