Shire plc (LSE: SHP, NASDAQ: SHPGY), the global specialty biopharmaceutical company, today announced that a study published in the September issue of the Journal of Clinical Psychiatry found once-daily VYVANSE significantly improved Attention Deficit Hyperactivity Disorder (ADHD) symptoms in adults within the first week of treatment. This study is the phase 3 pivotal trial submitted to the FDA and supported the approval in April 2008 of VYVANSE for adults with ADHD. VYVANSE was introduced in July 2007 for the treatment of ADHD in children aged 6 to 12 years and is now the fastest-growing ADHD prescription medication in the United States.

"This study adds to the growing body of research of ADHD in adults, and showed that VYVANSE provided effective symptom control for adults with this disorder," said Lenard A. Adler, M.D., lead researcher in this study and director of the Adult ADHD program at the NYU Langone Medical Center, associate professor of psychiatry, neurology and child and adolescent psychiatry at the New York University School of Medicine, as well as author of Scattered Minds: Help and Hope for Adults with ADHD (G. P. Putnam's Sons 2006). "It is important for people to realize that in adults, the core symptoms of ADHD - inattention, hyperactivity, and impulsivity - may present as inner restlessness, a lack of focus and organization, poor time management, or an inability to finish tasks, which can impact adults' daily lives. In this study, VYVANSE was shown, within the first week, to significantly improve ADHD symptoms of inattention, such as the ability to focus and organize, and hyperactivity and impulsivity, such as restlessness, and interrupting."

VYVANSE Significantly Improved ADHD Symptoms in Adults

In this randomized, double-blind, placebo-controlled, parallel-group, four-week study with dose escalations in 414 adults aged 18 to 55 years, adults with ADHD experienced significant improvements in ADHD symptoms within one week of treatment with once-daily VYVANSE.

Treatment with VYVANSE at all doses studied (30 mg, 50 mg, 70 mg) was significantly more effective than placebo, with a mean reduction in ADHD Rating Scale (ADHD-RS-IV) scores (16.2 to 18.6 points; P<.0001); demonstrating a 40 to 45 percent decrease at endpoint. ADHD-RS-IV is a standardized, validated test for assessing symptoms of ADHD and for assessing response to treatment. The scale, which contains 18 items, is based on the ADHD diagnostic criteria as defined in the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision®, a publication of the American Psychiatric Association.

Investigators also measured the efficacy of VYVANSE using the Clinical Global Impressions-Improvement (CGI-I) scale. On this scale, the percentage of adults taking VYVANSE rated by investigators as "much improved" or "very much improved" ranged from 57 to 61 percent at endpoint and was significantly greater than placebo (P<.01). The CGI-I is a standard assessment used to rate a patient's improvement over time.

The most common adverse events in the study were decreased appetite, difficulty falling asleep, and dry mouth.

"This study was one of the largest controlled stimulant trials in adults with ADHD, and these data reinforce the importance of VYVANSE as a new once-daily treatment option for adults with ADHD that significantly improved their ADHD symptoms," said Mike Cola, President of Shire's Specialty Pharmaceuticals business. "Shire recognizes the need for more research on ADHD in the adult population and is committed to advancing the science of ADHD and providing treatments that help children and adults diagnosed with ADHD to lead more productive lives."

VYVANSE is a therapeutically inactive prodrug, in which d-amphetamine is covalently bonded to l-lysine, and after oral ingestion it is converted to pharmacologically active d-amphetamine. The conversion of VYVANSE to d-amphetamine is not affected by gastrointestinal pH and is unlikely to be affected by alterations in normal GI transit times.

VYVANSE is available in six dosage strengths of 20 mg, 30 mg, 40 mg, 50 mg, 60 mg, and 70 mg. In its first year of availability, more than 2 million VYVANSE prescriptions have been filled.

Additional information about VYVANSE and Full Prescribing Information are available at http://www.vyvanse.com.

Dr. Adler has received grant/research support from Shire and is a member of the advisory board and consultant for Shire.

About VYVANSE

Vyvanse is indicated for the treatment of ADHD. Efficacy based on two controlled trials in children aged 6 to 12 and one controlled trial in adults.

Tell the doctor about any heart conditions, including structural abnormalities, that you, your child, or a family member, may have. Inform the doctor immediately if you or your child develops symptoms that suggest heart problems, such as chest pain or fainting.

Vyvanse should not be taken if you or your child has advanced disease of the blood vessels (arteriosclerosis); symptomatic heart disease; moderate to severe high blood pressure; overactive thyroid gland (hyperthyroidism); known allergy or unusual reactions to drugs called sympathomimetic amines (for example, pseudoephedrine); seizures; glaucoma; a history of problems with alcohol or drugs; agitated states; taken a monoamine oxidase inhibitor (MAOI) within the last 14 days.

Tell the doctor before taking Vyvanse if you or your child is being treated for or has symptoms of depression (sadness, worthlessness, or hopelessness) or bipolar disorder; has abnormal thought or visions, hears abnormal sounds, or has been diagnosed with psychosis; has had seizures or abnormal EEGs; has or has had high blood pressure; exhibits aggressive behavior or hostility. Tell the doctor immediately if you or your child develops any of these conditions or symptoms while taking Vyvanse.

Abuse of amphetamines may lead to dependence. Misuse of amphetamine may cause sudden death and serious cardiovascular adverse events. These events have also been reported rarely with amphetamine use.

Vyvanse was generally well tolerated in clinical studies. The most common side effects reported in studies of Vyvanse were: children - decreased appetite, difficulty falling asleep, stomachache, and irritability; adult - decreased appetite, difficulty falling asleep, and dry mouth.

Aggression, new abnormal thoughts/behaviors, mania, growth suppression, worsening of motion or verbal tics, and Tourette's syndrome have been associated with use of drugs of this type. Tell the doctor if you or your child has blurred vision while taking Vyvanse.

About ADHD

ADHD is one of the most common psychiatric disorders in children and adolescents. Approximately 7.8 percent of all school-aged children, or about 4.4 million US children aged 4 to 17 years, have been diagnosed with ADHD at some point in their lives, according to the U.S. Centers for Disease Control and Prevention (CDC). The disorder is also estimated to affect 4.4 percent of US adults aged 18-44 based on results from the National Comorbidity Survey Replication, a nationally representative household survey, which used a lay-administered diagnostic interview to access a wide range of DSM-IV disorders. When this percentage is extrapolated to the full US population, approximately 9.8 million adults are believed to have ADHD. ADHD is a psychiatric behavioral disorder that manifests as a persistent pattern of inattention and/or hyperactivity-impulsivity that is more frequent and severe than is typically observed in individuals at a comparable level of development. To be properly diagnosed with ADHD, a person needs to demonstrate at least six of nine symptoms of inattention; and/or at least six of nine symptoms of hyperactivity/impulsivity; that the symptoms continue for at least six months; the onset of some hyperactive, impulsive or inattentive symptoms that caused impairment appears before age 7 years; that some impairment from the symptoms is present in two or more settings (eg, at school and home); and that there is clinically significant impairment in social, academic, or occupational functioning and the symptoms cannot be better explained by another psychiatric disorder.

Although there is no "cure" for ADHD, there are accepted treatments that specifically target its symptoms. Standard treatments include educational approaches, psychological, or behavioral modification, and medication.

SHIRE plc

Shire's strategic goal is to become the leading specialty biopharmaceutical company that focuses on meeting the needs of the specialist physician. Shire focuses its business on attention deficit and hyperactivity disorder (ADHD), human genetic therapies (HGT) and gastrointestinal (GI) diseases as well as opportunities in other therapeutic areas to the extent they arise through acquisitions. Shire's in-licensing, merger and acquisition efforts are focused on products in specialist markets with strong intellectual property protection and global rights. Shire believes that a carefully selected and balanced portfolio of products with strategically aligned and relatively small-scale sales forces will deliver strong results.

For further information on Shire, please visit the Company's website: http://www.shire.com.

"Safe Harbor" Statement Under The Private Securities Litigation Reform Act Of 1995

Statements included herein that are not historical facts are forward-looking statements. Such forward-looking statements involve a number of risks and uncertainties and are subject to change at any time. In the event such risks or uncertainties materialize, the Company's results could be materially affected. The risks and uncertainties include, but are not limited to, risks associated with: the inherent uncertainty of pharmaceutical research, product development, manufacturing and commercialization including, but not limited to, the establishment in the market of VYVANSE™ (lisdexamfetamine dimesylate) (Attention Deficit and Hyperactivity Disorder ("ADHD")); the impact of competitive products, including, but not limited to, the impact of those on the Company's ADHD franchise; patents, including but not limited to, legal challenges relating to the Company's ADHD franchise; government regulation and approval, including but not limited to the expected product approval date of INTUNIV™ (guanfacine extended release) (ADHD); the Company's ability to secure new products for commercialization and/or development; the Company's proposed offer for Jerini AG, including but not limited to, the Company's ability to successfully complete the offer and integrate Jerini AG, as well as realize the anticipated benefits of the acquisition; and other risks and uncertainties detailed from time to time in the Company's filings with the Securities and Exchange Commission, including the Company's Annual Report on Form 10-K for the year ended December 31, 2007.

http://www.shire.com