LUNESTA(TM) Perimenopause-Menopause Study Data to Be Presented at North American Menopause Society Annual Meeting

In this six-week, 410-patient, randomized, double-blind,placebo-controlled study, nightly use of LUNESTA 3 mg resulted instatistically significant improvement from baseline compared withplacebo in patient-reported measures of sleep latency (time to sleeponset; p < or = 0.001), wake time after sleep onset (WASO; a sleepmaintenance measurement of the amount of time spent awake afterinitially falling asleep; p < or = 0.002), and total sleep time (p Compared to baseline and averaged over the double-blind period,women treated with LUNESTA reported fewer total nocturnal awakenings(p<0.0001) and fewer awakenings due to hot flashes (p=0.001) comparedto those patients administered placebo. A physician global assessment,which is a measure by which physicians evaluate their patients'overall change in menopausal symptoms, was statistically significantlyimproved (p<0.001) at the end of the treatment period for womentreated with LUNESTA 3 mg compared to those treated with placebo.Other findings include improvements from baseline in perimenopausalsymptoms as measured by the Greene Climacteric Scale (total scorep=0.03; psychological domain p=0.009; and vasomotor p=0.03), by theMenopause Quality of Life Scale (vasomotor p=0.003 and physical p=0.04domains) and by the Montgomery Aspberg Depression Rating Scale (MADRS;p=0.02).

The study also assessed changes in total sleep time, sleep latencyand sleep maintenance in the seven days following patients'discontinuation of LUNESTA treatment. The LUNESTA treatment group didnot experience rebound insomnia after discontinuation of LUNESTA.Rebound insomnia is defined as a dose-dependent temporary worsening ofsleep relative to baseline following abrupt discontinuation oftreatment.

"One of the effects associated with perimenopause and menopause isincreased incidence of waking up during the night and an inability tofall back to sleep, principally due to hot flashes," said Claudio N.Soares, M.D., Ph.D., Associate Professor, Department of Psychiatry andBehavioral Neurosciences, McMaster University and Co-Director, Women'sHealth Concerns Clinic at St. Joseph's Healthcare, Hamilton, Canada."This study of LUNESTA in women experiencing perimenopausal andmenopausal symptoms suggests that LUNESTA may provide them with relieffrom insomnia and therefore could potentially lead to a significantimprovement in their quality of life."

"Seventy-five percent of women report symptoms during menopausethat can include hot flashes, night sweats and insomnia," said KarenL. Giblin, President and Founder of PrimePlus/RedHotMamas, a leadingmenopause education provider. "It is encouraging to see additionalresearch directed toward assessing how LUNESTA might be able toameliorate the insomnia symptoms that accompany this life change."

Perimenopause in women is the transition period from regularreproductive function to complete cessation of the menstrual period,or menopause. During this transition, which can be years in duration,and continuing through to the post-menopausal period, the bodyexperiences both physical and hormonal changes, which can beassociated with a variety of symptoms. Problems sleeping and resultingfatigue may occur due to waking up in the middle of the night becauseof hot flashes or a need to go to the bathroom, which can lead totrouble falling back to sleep. During this time, women may alsoexperience trouble falling to sleep or waking up early in the morning.According to the Agency for Healthcare Research and Quality, up to 60percent of perimenopausal, menopausal, and postmenopausal womenexperience sleep disturbances.

"We recognize that a significant number of women experienceinsomnia that co-exists with the physical and hormonal changes andaccompanying symptoms that characterize this reproductive transitionalperiod," said Donna R. Grogan, M.D., Senior Vice President, ClinicalResearch at Sepracor. "This study, which is part of our Phase IIIB/IVLUNESTA program designed to investigate the effects of LUNESTA oninsomnia associated with underlying medical conditions, demonstratedthe efficacy and safety of LUNESTA in women with insomnia associatedwith the menopausal period and explored the added benefit it mayprovide in alleviating certain perimenopausal/menopausal symptoms."

LUNESTA is a new non-benzodiazepine indicated for the treatment ofinsomnia in patients who experience difficulty falling asleep as wellas for the treatment of patients who have difficulty sleeping throughthe night (sleep maintenance difficulty). LUNESTA is approved forlong-term use. LUNESTA 1 mg, 2 mg and 3 mg tablets are available byprescription in pharmacies nationwide.

An estimated 100 million adult Americans suffer from eitherchronic or occasional insomnia.(1) Symptoms of insomnia includedifficulty falling asleep, awakening frequently during the night,waking up too early, an inability to fall back to sleep or awakeningfeeling unrefreshed.

The U.S. market for prescription sleep products was approximately$2.1 billion in 2004, excluding products not indicated for thetreatment of insomnia that are nonetheless used in its treatment. Thisrepresents nearly a 19 percent increase over the previous year,according to IMS Health information.

Important Safety Information

LUNESTA works quickly and should only be taken immediately beforebedtime. Be sure you have at least eight hours to devote to sleepbefore becoming active. You should not engage in any activity aftertaking LUNESTA that requires complete alertness, such as driving a caror operating machinery. You should use extreme care when engaging inthese activities the morning after taking LUNESTA. Do not use alcoholwhile taking any sleep medicine. All sleep medicines carry some riskof dependency. Do not use sleep medicines for extended periods withoutfirst talking to your doctor. Side effects may include unpleasanttaste, headache, drowsiness and dizziness.

Please visit www.sepracor.com or www.lunesta.com to access theFDA-approved labeling text for LUNESTA.

About Sepracor

Sepracor Inc. is a research-based pharmaceutical company dedicatedto treating and preventing human disease through the discovery,development and commercialization of innovative pharmaceuticalproducts that are directed toward serving unmet medical needs.Sepracor's drug development program has yielded an extensive portfolioof pharmaceutical compound candidates with a focus on respiratory andcentral nervous system disorders. The company's commercializationefforts are carried out by its U.S.-based, 1,250-person, primary careand specialty-oriented sales force. Sepracor's corporate headquartersare located in Marlborough, Massachusetts.

This news release contains forward-looking statements that involverisks and uncertainties, including statements with respect to thesafety, efficacy and potential benefits of LUNESTA. Among the factorsthat could cause actual results to differ materially from thoseindicated by such forward-looking statements are: Sepracor's abilityto fund, and the results of, further clinical trials; the timing andsuccess of submission, acceptance and approval of additionalregulatory filings; label/use changes or concerns of LUNESTAprescribers or patients; and certain other factors that are detailedin the company's quarterly report on Form 10-Q for the quarter endedJune 30, 2005 filed with the Securities and Exchange Commission.

In addition, the statements in this press release representSepracor's expectations and beliefs as of the date of this pressrelease. Sepracor anticipates that subsequent events and developmentsmay cause these expectations and beliefs to change. However, whileSepracor may elect to update these forward-looking statements at somepoint in the future, it specifically disclaims any obligation to doso. These forward-looking statements should not be relied upon asrepresenting Sepracor's expectations or beliefs as of any datesubsequent to the date of this press release.

LUNESTA is a trademark of Sepracor Inc.

1) Extrapolated to current population from 2000 census based onAncoli-Israel et al. SLEEP. 1999;22 (suppl 2):S347-S353.

For a copy of this release or any recent release, visitwww.sepracor.com.