Shire Reports Positive Efficacy and Safety Results From FAST-3 Study of FIRAZYR(R) (icatibant) for Acute Attacks of Hereditary Angioedema

DUBLIN, December 1, 2010 - Shire plc (LSE: SHP, NASDAQ: SHPGY), the global specialty
biopharmaceutical company, today announced topline results from FAST-3 (For
Angioedema Subcutaneous Treatment), the largest of the Phase III trials
studying the use of FIRAZYR(R) (icatibant) for treatment of acute attacks of
hereditary angioedema (HAE).

The study showed that patients receiving treatment with FIRAZYR
experienced a significantly faster time to onset of symptom relief from
individual and combined cutaneous and abdominal HAE symptoms, compared to
those receiving placebo.

FIRAZYR provided a highly statistically significant and clinically
meaningful benefit relative to placebo for the primary endpoint of time to
onset of symptom relief for the first attack after study enrollment. This was
measured by a 50% reduction in a composite symptom score assessed by the
patient. The median time to onset of symptom relief for FIRAZYR by this
measure was 2.0 hours, compared with 19.8 hours for placebo.

FIRAZYR also provided a significantly shorter time to onset of symptom
relief of the patient's primary (main) symptom. This secondary efficacy
endpoint was measured by a 30% reduction in symptom score. The median time to
onset of relief for FIRAZYR by this measure was 1.5 hours, compared with 18.5
hours for placebo.

The results for both of these endpoints were highly statistically
significant (p<0.001).

Consistent with previous studies, FIRAZYR was generally well tolerated.

FIRAZYR is currently approved in 37 countries worldwide, including the
countries of the European Union, for the symptomatic treatment of acute
attacks of HAE in adults (with a C1-INH deficiency). In 2008 the U.S. Food
and Drug Administration (FDA) issued a not approvable letter for FIRAZYR. It
was agreed by Shire and the agency that an additional clinical study (FAST-3)
would be required to support the New Drug Application (NDA) filing in the US.
Shire now expects to file a complete response to the FDA's not approvable
letter early in 2011.

"These very positive and clinically meaningful results represent a
significant milestone in the U.S. clinical development program for FIRAZYR,"
said Sylvie Gregoire, President of Shire HGT. "We are currently preparing our
complete response and we look forward to working with the FDA to provide Type
1 and Type 2 HAE patients in the U.S. with an additional treatment option
that holds the potential to offer quick access to effective treatment."

About the Phase III Study

The FAST-3 study, conducted in 67 sites in 9 countries, was a randomized,
double-blind, placebo controlled multicenter trial of FIRAZYR administered by
subcutaneous injection for the treatment of patients with acute attacks of
HAE. A total of 88 patients who presented with moderate to very severe
cutaneous and/or abdominal symptoms were enrolled in the double blind phase,
with an approximately equal number in each arm of the study. Patients with
HAE attacks who presented with mild to moderate laryngeal symptoms were also
randomized and enrolled in the double-blind phase. Patients who presented
with severe laryngeal attacks immediately received open-label FIRAZYR. All
laryngeal patients were considered additional to the 88 patients with
abdominal and/or cutaneous attacks who were randomized and enrolled. The
primary analysis population consisted of those patients with cutaneous and/or
abdominal symptoms who were randomized to either FIRAZYR or placebo (the
non-laryngeal intent-to-treat population). After the first attack, patients
had the option for subsequent attacks to be treated with open-label FIRAZYR.

In addition to the endpoints discussed above, other secondary efficacy
endpoints included time to symptom relief using patient and investigator
assessment tools, evaluation of global outcomes for all patients using the
symptom severity score, and time to initial as well as almost complete
symptom improvement. Safety evaluations included adverse events, vital signs,
ECGs, laboratory parameters, antigenicity, and local injection site
tolerability. Full results will be presented at an upcoming scientific
meeting.

About FIRAZYR (icatibant)

The active substance, icatibant, is a specific bradykinin B2 receptor
antagonist. It represents a novel, targeted, subcutaneously-administered
approach to the treatment of HAE attacks by blocking effects of bradykinin,
the key mediator of edema formation. Icatibant has been shown to provide
rapid symptom improvement and shorten the duration of an attack. Icatibant is
a synthetic decapeptide (a peptide containing ten amino acids).

Icatibant is currently approved in 37 countries worldwide, including the
countries of the European Union, for the symptomatic treatment of acute
attacks of HAE in adults (with a C1-INH deficiency). Where commercially
available, the drug is supplied in a pre-filled 3 ml syringe. Icatibant can
be stored at up to 25 degrees Celsius without refrigeration.

Shire has recently submitted data from the Phase IIIb EASSI (Evaluation
of the Safety of Self-Administration With Icatibant) study of icatibant to
the European Medicines Agency (EMA) for a proposed label amendment to include
self-administration of subcutaneous icatibant to treat acute attacks of HAE.

EASSI was designed to evaluate the safety, tolerability, and efficacy of
self-administered subcutaneous injections of icatibant during acute HAE
attacks in icatibant naive and non-naive hereditary angioedema (HAE)
patients. Interim data from the EASSI study was presented at American College
of Allergy, Asthma and Immunology (ACAAI) in 2010.

Icatibant is not available in all countries and prescribing information
may differ between countries. Please consult your local prescribing
information.

Important Safety Information

Almost all subjects who were treated with icatibant in clinical trials
developed reactions at the site of injection (characterized by skin
irritation, swelling, pain, itchiness, erythema, burning sensation). Caution
should be observed when icatibant is administered to patients with acute
ischemic heart disease or unstable angina pectoris and in the weeks following
a stroke.

About HAE

HAE is a rare genetic disease. Type I and Type II HAE are caused by low
levels or a dysfunction of C1 esterase inhibitor (C1-INH). Reduced C1-INH
activity can lead to elevated plasma levels of bradykinin, the key mediator
of HAE symptoms. HAE is characterized by recurrent sudden attacks of edema
(swelling) of the skin (hands, arms, feet, legs, thighs, face, genitals) or
the mucous membranes (gastrointestinal tract, larynx or voicebox). The
swelling can be disfiguring and painful, especially in the case of abdominal
attacks. Laryngeal attacks are potentially life-threatening due to the risk
of suffocation. Unlike angioedemas caused by allergic reactions, signs and
symptoms such as hives and itching do not occur in HAE.

Notes to editors

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.

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    For further information please contact:

    Investor Relations: Eric Rojas       erojas@shire.com    +1-781-482-0999

    Media:              Jessica Mann     jmann@shire.com     +44-1256-894-280
                        Jessica Cotrone  jcotrone@shire.com  +1-781-482-9538

For further information please contact: Investor Relations: Eric Rojas, erojas at shire.com, +1-781-482-0999; Media: Jessica Mann, jmann at shire.com, +44-1256-894-280; Jessica Cotrone, jcotrone at shire.com, +1-781-482-9538