New Study Evaluating the ADHD Medication VYVANSE(R) (lisdexamfetamine dimesylate)...

New Study Evaluating the ADHD Medication VYVANSE(R) (lisdexamfetamine
dimesylate) CII Demonstrated No Change in the Pharmacokinetic Profile of
VYVANSE When Coadministered with Prilosec OTC(R) 40 mg (20 mg X 2), a Commonly
Used Proton Pump Inhibitor (PPI)

PHILADELPHIA, May 22 /PRNewswire-FirstCall/ -- Shire plc (LSE: SHP, Nasdaq:
SHPGY), the global specialty biopharmaceutical company, announced results of a
study showing that coadministration of the ADHD medication VYVANSE(R)
(lisdexamfetamine dimesylate) CII with the proton pump inhibitor (PPI)
Prilosec OTC(R) 40 mg (20 mg X 2), did not alter the median time it took for
maximum plasma concentration of d-amphetamine to be reached in the subjects
evaluated. In the same study, coadministration of Prilosec OTC with ADDERALL
XR resulted in a nearly 45 percent reduction in the median time to reach
maximum plasma concentrations of amphetamine, the active medication. Other
pharmacokinetic parameters (maximum plasma concentration and area under curve)
of active medication were not altered for either VYVANSE or ADDERALL XR when
coadministered with Prilosec OTC. This study, which is the first to evaluate
the pharmacokinetics of VYVANSE and ADDERALL XR taken alone and with Prilosec
OTC 40 mg, was recently presented at the International Congress on Clinical
Pharmacy, co-sponsored by the American College of Clinical Pharmacy (ACCP), in
Orlando, FL.

"Since its approval for ADHD in adults in 2008, VYVANSE has been an important
treatment option for physicians treating adult patients seeking significant
ADHD symptom control during their busy day," said Jeffrey Jonas, Senior Vice
President of Research & Development for the Specialty Pharmaceuticals business
at Shire. "This study is the first to evaluate the impact of a proton pump
inhibitor on the amphetamine pharmacokinetics of VYVANSE and ADDERALL XR and
further supports that, as a prodrug, VYVANSE does not rely on pH for its
absorption or conversion."

Heartburn is a common problem affecting millions of Americans. Prilosec OTC
and other proton pump inhibitors reduce the acidity (increase the pH) in the
stomach and are commonly used by millions of adults in the United States who
suffer from acid reflux. ADHD is estimated to affect 4.4 percent of US adults
aged 18 to 44 based on results from the National Comorbidity Survey
Replication. When this percentage is extrapolated to the full US population
aged 18 and over, approximately 9.8 million adults are believed to have ADHD."

"These study findings may be of particular significance for adults who are
taking an ADHD medication along with a proton pump inhibitor, as proton pump
inhibitors tend to decrease the production of acid in the stomach," said Dr.
Matthew Brams, a psychiatrist in private practice with Bayou City Research,
Ltd. in Houston, TX. "In this study, the conversion of VYVANSE to its active
form was not affected when coadministered with Prilosec OTC 40 mg, which
relates to the characteristics of VYVANSE as a prodrug stimulant."

As a prodrug, VYVANSE is converted to its active form by the body's natural
metabolism. This conversion takes place minimally in the gastrointestinal
tract and primarily in the blood. Additional pharmacokinetic studies have
demonstrated that the conversion of VYVANSE to active medication is unlikely
to be affected by alterations in GI transit times and does not rely on gastric
pH. ADDERALL XR has a drug delivery system which utilizes immediate release
and pH dependent release beads. This pH-dependent delivery system has one
type of bead designed to be released immediately and the other type to be
released approximately four hours later in the lower intestine where pH levels
are higher.

The drug interactions section of the ADDERALL XR product labeling states that
coadministration of ADDERALL XR and proton pump inhibitors should be avoided,
as these medications act on proton pumps by blocking acid production thereby
reducing gastric acidity.

About the Study
This phase I, open-label, randomized, four-period crossover study evaluated
the pharmacokinetics of VYVANSE and ADDERALL XR, alone and with Prilosec OTC
40 mg, among 24 healthy adults aged 18 to 45 years. In the study, subjects
were administered single oral doses of VYVANSE 50 mg and ADDERALL XR 20 mg at
four-day intervals. Following washout, subjects then began a regimen of 40 mg
Prilosec OTC once daily for 14 days. Alternate single doses of VYVANSE 50 mg
and ADDERALL XR 20 mg were added on days seven and 11.

When ADDERALL XR was administered alone, the median time to maximum plasma
amphetamine concentration was five hours. The median time to maximum
amphetamine plasma concentration was shortened from five hours to 2.75 hours
when ADDERALL XR was coadministered with Prilosec OTC 40 mg. Approximately 57
percent of subjects who received ADDERALL XR with Prilosec OTC had a shortened
time to maximum amphetamine plasma concentration of greater than or equal to
one hour. When VYVANSE was administered alone, the median time to maximum
plasma d-amphetamine concentration was three hours. This remained unchanged
when VYVANSE was coadministered with Prilosec OTC. Approximately 25 percent
of subjects who received VYVANSE with Prilosec OTC had a shortened time to
maximum d-amphetamine plasma concentration of greater than or equal to one
hour. The study showed while time to maximum plasma concentration with
ADDERALL XR was affected by coadministration with a Prilosec OTC,
coadministration with VYVANSE or ADDERALL XR did not affect the maximum plasma
concentration or overall exposure to active medication.

Safety was also evaluated during the study. The most common (greater than or
equal to 5 percent) treatment emergent adverse events associated with VYVANSE
were anxiety, vasospasm, headache, dizziness, palpitations, and tachycardia.
The most common (greater than or equal to 5 percent) treatment emergent
adverse events associated with ADDERALL XR were vasospasm and anxiety.

VYVANSE, which was introduced in the United States in July 2007 for the
treatment of ADHD in children aged 6 to 12 years and approved in April 2008 to
treat ADHD in adults, is currently available in six dosage strengths of 20 mg,
30 mg, 40 mg, 50 mg, 60 mg, and 70 mg. To date, more than 5 million VYVANSE
prescriptions have been filled, bringing the current US market share to nearly
12 percent based on weekly branded prescription volume. Additionally, VYVANSE
formulary coverage has been positive, with 10 of Shire's top 11 managed care
organizations covering the product in a preferred formulary position.

Additional information about VYVANSE and Full Prescribing Information,
including the Medication Guide, are available at www.vyvanse.com. Additional
information about ADDERALL XR and Full Prescribing Information, including the
Medication Guide, are available at www.adderallxr.com.

Note: Prilosec OTC is a registered trademark of Procter & Gamble.

About VYVANSE and ADDERALL XR

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.
Adderall XR is indicated for the treatment of ADHD.

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 or Adderall XR 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 or Adderall XR 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 or Adderall
XR.

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.

Talk to your health care provider if your child experiences slowing of growth
(height and weight). Children should have their height and weight checked
periodically while taking Vyvanse or Adderall XR. Your healthcare provider may
stop Vyvanse or Adderall XR treatment if a problem is found during these
check-ups.

Vyvanse and Adderall XR were 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. The
most common side effects reported in studies of Adderall XR were: children -
decreased appetite, difficulty falling asleep, stomachache, and emotional
lability; adolescents - loss of appetite, difficulty falling asleep,
stomachache, and weight loss; adults - dry mouth, loss of appetite, difficulty
falling asleep, headache, and weight loss.

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 or Adderall XR.

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 US 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. When this percentage is extrapolated to the full US population
aged 18 and over, 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. The specific etiology of ADHD is unknown and there is no single
diagnostic test for this syndrome. 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 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 website:
www.shire.com.

THE "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

Mindy Huber, +1-212-601-8330, +1-917-653-6134 (mobile),
Mindy.Huber@porternovelli.com; or Lauren Plate, +1-212-601-8188,
+1-516-319-6729 (mobile), Lauren.Plate@porternovelli.com