Shire To Present Additional Scientific Data On ADHD Treatment Portfolio At American Psychiatric Association Annual Meeting

Shire plc (LSE: SHP, NASDAQ: SHPGY), the global specialty biopharmaceutical company, announced today that it will present key scientific data on its Attention Deficit Hyperactivity Disorder (ADHD) treatments, lisdexamfetamine dimesylate, methylphenidate transdermal system and the investigational non-stimulant treatment under FDA review, guanfacine extended release, at the American Psychiatric Association (APA) annual meeting to be held May 3rd to 8th in Washington, D.C.

"Shire is committed to the advancement of ADHD research, and we are pleased to be presenting the efficacy and safety results from several studies of our ADHD treatments," said Gwendolyn Niebler, Vice President of Global Medical Affairs at Shire. "We believe the physician community will find the lisdexamfetamine dimesylate, methylphenidate transdermal system and guanfacine extended release study findings to be presented at APA a relevant contribution to the growing body of research on our ADHD treatment options."

A summary of the key scientific presentations is provided below. Information about these data presentations mentioned in this release is embargoed until the respective presentation sessions have taken place at the meeting.

Lisdexamfetamine Dimesylate:
May 7, 2008; 12:00 p.m. ET
Lisdexamfetamine Dimesylate Treatment in Children Diagnosed with ADHD: Parental Impressions and Experiences
APA Poster Presentation # NR6-025

May 8, 2008; 11:00 a.m. ET
Efficacy and Safety of Lisdexamfetamine Dimesylate in Adults with ADHD
APA Oral Presentation Session # 28

Methylphenidate Transdermal System:
May 7, 2008; 12:00 p.m. ET
Long-Term Treatment Effects of the Methylphenidate Transdermal System in Boys and Girls with ADHD
APA Poster Presentation # NR6-018

Guanfacine Extended Release:
May 7, 2008; 12:00 p.m. ET
Guanfacine Extended Release: Duration of Effect in Children and Adolescents Aged 6 to 17 Years With ADHD
APA Poster Presentation # NR6-008

May 7, 2008; 12:00 p.m. ET
Response to Guanfacine Extended Release in Children and Adolescents Aged 6 to 17 Years With ADHD
APA Poster Presentation # NR6-040

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 U.S. 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 U.S. 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 assess a wide range of DSM-IV disorders.

ADHD is a neurobiological 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 child needs to demonstrate at least six of nine symptoms of inattention; and/or at least six of nine symptoms of hyperactivity/impulsivity; the onset of which appears before age 7 years; that some impairment from the symptoms is present in two or more settings (e.g., at school and home); that the symptoms continue for at least six months; 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. The most common 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), gastrointestinal (GI) and renal diseases. The structure is sufficiently flexible to allow Shire to target new therapeutic areas to the extent opportunities arise through acquisitions. Shire's in-licensing, merger and acquisition efforts are focused on products in niche markets with strong intellectual property protection either in the US or Europe. Shire believes that a carefully selected portfolio of products with strategically aligned and relatively small-scale sales forces will deliver strong results.