INTUNIV(TM) - Shire Files Suit Against Actavis Elizabeth LLC and Actavis Inc.

DUBLIN and PHILADELPHIA, May 13, 2010 - Shire plc (LSE: SHP, NASDAQ: SHPGY), the global specialty
biopharmaceutical company, announces that its subsidiary Shire LLC has filed
a lawsuit in the U.S. District Court for the District of Delaware against
Actavis Elizabeth LLC and Actavis Inc. (collectively "Actavis") for the
infringement of U.S. Patent Nos. 5,854,290 (the '290 patent), 6,287,599 (the
'599 patent), and 6,811,794 (the '794 patent).

The lawsuit results from an Abbreviated New Drug Application (ANDA) filed
by Actavis for generic versions of 1 mg, 2 mg, 3 mg and 4 mg guanfacine
hydrochloride extended release tablets, INTUNIV(TM), which seeks to market
such generic products before the expiration of the '290, '599, and '794
patents. The regulatory exclusivity period for INTUNIV(TM) runs through
September 2, 2012.

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 affected. The risks and uncertainties include, but are not limited
to, risks associated with: the inherent uncertainty of pharmaceutical
research, product development, manufacturing and commercialization including,
but not limited to, the establishment in the market of VYVANSE(TM)
(lisdexamfetamine dimesylate) (Attention Deficit Hyperactivity Disorder
("ADHD")); the impact of competitive products, including, but not limited to,
the impact of those on the Company's ADHD franchise; patents, including but
not limited to, legal challenges relating to the Company's ADHD franchise;
government regulation and approval, including but not limited to the expected
product approval date of INTUNIV(TM) (guanfacine extended release) (ADHD);
the Company's ability to secure new products for commercialization and/or
development; the Company's proposed offer for Jerini AG, including but not
limited to, the Company's ability to successfully complete the offer and
integrate Jerini AG, as well as realize the anticipated benefits of the
acquisition; and other risks and uncertainties detailed from time to time in
the Company's filings with the Securities and Exchange Commission, including
the Company's Annual Report on Form 10-K for the year ended December 31,
2007.

    For further information please contact:

    Investor Relations: Clea Rosenfeld (Rest of the World) +44-1256-894-160
                        Eric Rojas (North America)         +1-781-482-0999
    Media:              Jessica Mann (Rest of the World)   +44-1256-894-280
                        Matthew Cabrey (North America)     +1-484-595-8248

For further information please contact: Investor Relations: Clea Rosenfeld (Rest of the World), +44-1256-894-160; Eric Rojas (North America), +1-781-482-0999; Media: Jessica Mann (Rest of the World), +44-1256-894-280; Matthew Cabrey (North America), +1-484-595-8248