FDA Advisory Committee Strongly Recommends Approval and Self-Administration of FIRAZYR (icatibant)

FDA Advisory Committee Strongly Recommends Approval and Self-Administration of FIRAZYR® (icatibant) for the Treatment of Acute Attacks of Hereditary Angioedema

Dublin, Ireland and Lexington, Massachusetts, US - June 23, 2011 - Shire plc (LSE: SHP, NASDAQ: SHPGY), the global specialty biopharmaceutical company, today announced that the Pulmonary-Allergy Drugs Advisory Committee to the U.S. Food and Drug Administration (FDA) recommended, by a vote of twelve to one, that the efficacy and safety data provides substantial evidence to support approval of FIRAZYR® (icatibant) for the treatment of acute attacks of hereditary angioedema (HAE) in patients 18 years and older. In addition, by a vote of eleven to one, with one abstention, the Committee recommended self-administration of the drug by patients.

The Committee's input will be considered by the FDA in its review of the New Drug Application for FIRAZYR. The FDA is not bound by the Committee's guidance, but takes its advice into consideration when reviewing investigational medicines. The Company has been assigned an action date of August 25, 2011 under the Prescription Drug User Fee Act.

"Due to the unpredictable and potentially life-threatening nature of HAE attacks, we believe that self-administration of FIRAZYR can represent an effective and convenient treatment for patients to better manage their disease," said Sylvie Grégoire, President of Shire HGT. "We will continue to work closely with the FDA as it prepares to make its final decision on the FIRAZYR application."

In considering whether FIRAZYR is safe and effective, the Committee considered data from three double-blind, randomized, controlled phase III trials, known as the FAST-1, FAST-2, and FAST-3 studies. The results from these trials, which included patients with cutaneous, abdominal, and laryngeal attacks, provided substantial and convincing evidence of clinically meaningful benefit of FIRAZYR for the treatment of acute HAE attacks in adults. Treatment of acute attacks with 30 mg of FIRAZYR administered subcutaneously was generally well tolerated with a consistent safety profile across all clinical studies. Key study symptom measures included time to onset of symptom relief, based on measures of abdominal pain, skin pain, skin swelling, and measured time to a clinically relevant effect for the primary (main) symptom of attack from the patient's perspective.

In FAST-3, FIRAZYR provided a statistically significant and clinically meaningful benefit relative to placebo for the primary endpoint of time to onset of symptom relief, which was defined as 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 for the patient's primary symptom. The median time to onset of relief for FIRAZYR by this measure was 1.5 hours, compared with 18.5 hours for placebo. For both of these endpoints, the differences between FIRAZYR and placebo were statistically significant (p<0.001). The median times to onset of symptom relief for patients treated with icatibant in the FAST-1 and FAST-2 studies were consistent with the results in the FAST-3 study.

A Phase IIIb Evaluation of the Safety of Self-Administration with Icatibant (EASSI) study showed that self-administration of FIRAZYR for acute attacks of HAE was generally well-tolerated. Times to symptom relief following FIRAZYR administration were similar whether self-administered or administered by a healthcare professional, and consistent with the Phase 3 data.

Across the studies, almost all patients experienced injection site reactions which were transient and generally did not require clinical intervention. Other common adverse reactions included nausea, fever, dizziness, headache, and rash. The safety experience reported in the self-administration study was similar.

About FIRAZYR

The active substance, icatibant, is a potent and selective 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.

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, for the symptomatic treatment of acute attacks of HAE in adults (with a C1-INH deficiency). FIRAZYR 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 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 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.