FDA Assigns PDUFA Date for Shire's FIRAZYR(R) (icatibant) for the Treatment of Acute Attacks of Hereditary Angioedema

DUBLIN and LEXINGTON, Massachusetts, March 21, 2011 - Shire plc (LSE: SHP, NASDAQ: SHPGY), the global specialty
biopharmaceutical company, today announced that the US Food and Drug
Administration (FDA) has assigned a Prescription Drug User Fee Act (PDUFA)
date of August 25, 2011 for the review of the New Drug Application (NDA) for
FIRAZYR(R) (icatibant) for the treatment of acute attacks (Types I and II) of
hereditary angioedema (HAE). This 6 month review timeline is consistent with
review as a Class II resubmission.

Shire's complete response to the not approvable letter issued by the FDA
includes additional data requested by the agency regarding FIRAZYR's efficacy
and safety in treating HAE attacks. Shire conducted an additional Phase III
clinical study (FAST-3), and in December 2010 reported positive efficacy and
safety results. The Company's complete response is based on recent results
from the FAST-3 study and the ongoing self-administration study, as well as
the previously published FAST-1 and FAST-2 studies.

About FIRAZYR

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 designed to block the effects of
bradykinin, the key mediator of edema formation. FIRAZYR is a synthetic
decapeptide (a peptide containing ten amino acids).

The European Commission has approved FIRAZYR for self-administration
after training in subcutaneous injection technique by a healthcare
professional. FIRAZYR is the first and only treatment for acute Type I and
Type II HAE attacks licensed for self-administration in Europe.

FIRAZYR has an orphan drug designation status in the EU and US for
treatment of hereditary angioedema. Where commercially available, the drug is
supplied in a pre-filled 3 ml syringe. FIRAZYR can be stored at up to 25
degrees Celsius without refrigeration.

FIRAZYR is currently approved outside of the US in 37 countries
worldwide, including the countries of the European Union. Prescribing
information may differ between countries. Please consult your local
prescribing information.

Important Safety Information

Almost all subjects who were treated with FIRAZYR in clinical trials
developed reactions at the site of injection (characterized by skin
irritation, swelling, pain, itchiness, erythema, and burning sensation).
Caution should be observed when FIRAZYR 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 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. Signs and symptoms of HAE do not
respond to standard treatments for allergic angioedema.

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.

"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.

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