New Data Show Once-Daily INTUNIV(TM) (guanfacine) Extended Release Tablets Demonstrated Significant ADHD Symptom Reduction when Assessed Using the Oppositional Subscale of the Conners' ADHD Rating Scale

New Data Show Once-Daily INTUNIV(TM) (guanfacine) Extended Release Tablets
Demonstrated Significant ADHD Symptom Reduction when Assessed Using the
Oppositional Subscale of the Conners' ADHD Rating Scale
INTUNIV, recently approved by the FDA as the first nonscheduled alpha-2A
agonist indicated for the treatment of ADHD in children and adolescents, will
soon be available in pharmacies nationwide

HONOLULU, Oct. 29 /PRNewswire-FirstCall/ -- Shire plc (LSE: SHP, Nasdaq:
SHPGY), the global specialty biopharmaceutical company, announced new study
results on INTUNIV(TM) (guanfacine) Extended Release Tablets, at a major
psychiatric medical meeting today. The primary objective of this study was to
assess the change from baseline on the oppositional subscale of the Conners'
Parent Rating Scale-Revised: Long Form (CPRS-R:L) in patients ages 6 to 12
with a primary diagnosis of Attention-Deficit/Hyperactivity Disorder (ADHD)
with the presence of oppositional symptoms at baseline. INTUNIV met the
primary objective demonstrating significant efficacy in reducing symptoms as
measured by the oppositional subscale. Some of the symptoms measured by this
scale include deliberately doing things that annoy others, refusing to comply
with adults' requests, and being touchy or easily annoyed by others.

According to the Centers for Disease Control and Prevention (CDC),
approximately 7.8 percent of all US school-aged children have been diagnosed
with ADHD at some point in their lives. ADHD is a complex neurobehavioral
disorder, which includes symptoms and behaviors such as inattentiveness,
running around or climbing excessively, and being excitable or impulsive, many
of which can be disruptive.

"The disruptive nature of ADHD can impact social and academic settings for
those patients diagnosed with the disorder," said F. Randy Sallee, MD, PhD,
Professor of Psychiatry at the University of Cincinnati and Cincinnati
Children's Hospital Medical Center in Cincinnati, Ohio. "This study showed
that INTUNIV is an effective option for treating a range of ADHD symptoms."

INTUNIV, a once-daily formulation of guanfacine, was approved by the US Food
and Drug Administration (FDA) on September 2, 2009 as the first selective
alpha-2A agonist for the treatment of ADHD. Although the mechanism of action
is not known, guanfacine, the active ingredient in INTUNIV, is thought to
selectively stimulate alpha-2A adrenoreceptors in the prefrontal cortex.
Stimulation of the postsynaptic alpha-2A receptors is thought to strengthen
working memory, reduce susceptibility to distraction, improve attention
regulation, improve behavioral inhibition, and enhance impulse control.

Once-daily INTUNIV is expected to be available in US pharmacies in November
and will come in four dosage strengths (1 mg, 2 mg, 3 mg, and 4 mg). INTUNIV
is not a controlled substance and has no known potential for abuse or
dependence.

INTUNIV Demonstrated Significant Symptom Reduction in Patients Diagnosed with
ADHD and the Presence of Oppositional Symptoms

This randomized, placebo-controlled, flexible-dose study was conducted in 214
patients ages 6 to 12 over a nine-week period. INTUNIV demonstrated
significant ADHD symptom improvement in the primary and secondary measures as
demonstrated on the Oppositional Subscale of the CPRS-R:L and the ADHD Rating
Scale-IV (ADHD-RS-IV), respectively. The CPRS-R:L is a comprehensive scale
that uses parent observer and self-report ratings to help assess ADHD symptoms
and behaviors in children. At the study's end, patients taking INTUNIV showed
significant symptom reduction as compared to patients taking placebo (-10.9
versus -6.8; effect size 0.59; P<.001) when assessed using the oppositional
subscale of the CPRS-R:L. The ADHD-RS-IV scale assesses hyperactive,
impulsive, and inattentive ADHD symptoms. ADHD-RS-IV mean change from
baseline for INTUNIV versus placebo was -23.8 versus -11.5; effect size 0.92;
P<.001. In this study, most treatment-emergent adverse events were mild to
moderate. The most commonly reported treatment-emergent adverse events in
patients taking INTUNIV (greater than or equal to 10 percent) were somnolence,
headache, sedation, upper abdominal pain, and fatigue.

Dr Sallee added, "The data presented today provide additional support for the
safety and efficacy profile of INTUNIV. The trial's flexible dose design
gives clinicians a better look at how this medication may be used in clinical
practice once it becomes available in November."

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

Important Safety Information
INTUNIV is indicated for the treatment of Attention Deficit Hyperactivity
Disorder (ADHD) in children and adolescents aged 6 to 17. Efficacy was
established in two controlled clinical trials (8 and 9 weeks in duration). The
physician electing to use INTUNIV for extended periods should periodically
reevaluate its long-term usefulness for the individual patient.

INTUNIV should not be used in patients with a history of hypersensitivity to
guanfacine or any of its inactive ingredients or by patients taking other
products containing guanfacine.

Hypotension, bradycardia, and syncope were observed in clinical trials. Use
INTUNIV with caution in treating patients who have experienced hypotension,
bradycardia, heart block, or syncope, or who may have a condition that
predisposes them to syncope; are treated concomitantly with antihypertensives
or other drugs that can reduce blood pressure or heart rate or increase the
risk of syncope. Heart rate and blood pressure should be measured prior to
initiation of therapy, following dose increases, and periodically while on
therapy. Patients should be advised to avoid becoming dehydrated or
overheated.

Sedation and somnolence were commonly observed in clinical trials. The
potential for additive sedative effects with CNS depressant drugs should be
considered. Patients should be cautioned against operating heavy equipment or
driving until they know how they respond to INTUNIV. Avoid use with alcohol.

Common adverse reactions in patients taking INTUNIV that may be dose related
over the range of 1 to 4 mg/day include somnolence, sedation, abdominal pain,
dizziness, hypotension/decreased blood pressure, dry mouth, and constipation.

About ADHD
ADHD is one of the most common psychiatric disorders in children and
adolescents. Worldwide prevalence of ADHD is estimated at 5.3 percent (with
large variability), according to a comprehensive systematic review of this
topic published in 2007 in the American Journal of Psychiatry. In the United
States, approximately 7.8 percent of all school-aged children, or about 4.4
million children aged 4 to 17 years, have been diagnosed with ADHD at some
point in their lives, according to the Centers for Disease Control and
Prevention (CDC).

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. The specific etiology of ADHD is unknown and there is no single
diagnostic test for this disorder. Adequate diagnosis requires the use of
medical and special psychological, educational, and social resources,
utilizing diagnostic criteria such as Diagnostic and Statistical Manual of
Mental Disorders-IV (DSM-IV®) or International Classification of Diseases 10
(ICD-10).

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/or 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 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 Web site:
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
adversely affected. The risks and uncertainties include, but are not limited
to, risks associated with: the inherent uncertainty of research, development,
approval, reimbursement, manufacturing and commercialization of the Company's
Specialty Pharmaceutical and Human Genetic Therapies products, as well as the
ability to secure and integrate new products for commercialization and/or
development; government regulation of the Company's products; the Company's
ability to manufacture its products in sufficient quantities to meet demand;
the impact of competitive therapies on the Company's products; the Company's
ability to register, maintain and enforce patents and other intellectual
property rights relating to its products; the Company's ability to obtain and
maintain government and other third-party reimbursement for its products; and
other risks and uncertainties detailed from time to time in the Company's
filings with the Securities and Exchange Commission.

SOURCE Shire plc

Media: Matthew Cabrey (North America), +1-484-595-8248; Debra Gemme (Porter
Novelli for Shire), +1-703-298-4030, Alana Brier (Porter Novelli for Shire),
+1-212-601-8432