8-K

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the

Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): March 21, 2007

Shire plc

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(Exact name of registrant as specified in its charter)

England and Wales

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(State or other jurisdiction of incorporation)

0-29630	98-0484822
(Commission File Number)	(IRS Employer Identification No.)

Hampshire International Business Park, Chineham, Basingstoke,

Hampshire RG24 8EP England

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(Address of principal executive offices)                        (Zip code)

Registrant's telephone number, including area code                  44 1256 894 000

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(Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2.):

o Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

o Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

o Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

o Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.f13e-4(c))

Item 8.01. Other Events

Shire plc has issued the press release attached as Exhibit 99.01 which is incorporated by reference herein.

Item 9.01.	Financial Statements and Exhibits
	(d)	Exhibits. The following exhibit is filed herewith:
99.01		Press Release dated March 21, 2007

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

SHIRE PLC
By:	/s/ A C Russell
	Name:Angus Russell
	Title:Chief Financial Officer

Dated: March 21, 2007

EXHIBIT INDEX
Number	Description
99.01	Press Release dated March 21, 2007

EX-99.1

EXHIBIT 99.01

Hampshire International Business Park Chineham Basingstoke Hampshire RG24 8EP United Kingdom Tel +44 (0)1256 894000 Fax +44 (0)1256 894708 www.shire.com
Press Release

ADDERALL XR^® - Shire Files Suit against Colony Pharmaceuticals, Inc., Actavis, Inc. and Actavis Group hf

Basingstoke, UK and Philadelphia, US - March 21, 2007 - Shire plc (LSE: SHP, NASDAQ: SHPGY, TSX: SHQ) announces that its subsidiary Shire LLC has filed a lawsuit in the U.S. District Court for the District of Maryland against Colony Pharmaceuticals, Inc., Actavis, Inc., and Actavis Group hf (collectively “Colony”) for infringement of Shire’s U.S. Patent Nos. 6,322,819, 6,605,300 and 6,913,768.

The lawsuit results from an ANDA (Abbreviated New Drug Application) filed by Colony for generic versions of 5 mg, 10 mg, 15 mg, 20 mg, 25 mg and 30 mg ADDERALL XR^®, pursuant to which Colony provided notice in November 2004 that it would seek to market its generic products before the expiration of Shire’s patents. The lawsuit alleges that all of Colony’s generic strengths infringe the three patents in suit.

Adderall XR^® is Shire’s Attention Deficit Hyperactivity Disorder (“ADHD”) medicine.

For further information please contact:

Investor Relations	Cléa Rosenfeld (Rest of the World)	+44 1256 894 160
	Eric Rojas (North America)	+1 484 595 8252
Media	Jessica Mann (Rest of the World)	+44 1256 894 280
	Matthew Cabrey (North America)	+1 484 595 8248

Notes to editors

SHIRE PLC

Shire’s strategic goal is to become the leading specialty pharmaceutical company that focuses on meeting the needs of the specialist physician. Shire focuses its business on attention deficit and hyperactivity disorder (ADHD), human genetic therapies (HGT), gastrointestinal (GI) and renal diseases. The structure is sufficiently flexible to allow Shire to target new therapeutic areas to the extent opportunities arise through acquisitions. Shire

Registered in England 2883758 Registered Office as above

believes that a carefully selected portfolio of products with a strategically aligned and relatively small-scale sales force will deliver strong results.

Shire’s focused strategy is to develop and market products for specialty physicians. Shire’s in-licensing, merger and acquisition efforts are focused on products in niche markets with strong intellectual property protection either in the US or Europe.

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, Shire'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; the impact of competitive products, including, but not limited to the impact of those on Shire's Attention Deficit and Hyperactivity Disorder (ADHD) franchise; patents, including but not limited to, legal challenges relating to Shire's ADHD franchise; government regulation and approval, including but not limited to the expected product approval dates of SPD503 (guanfacine extended release) (ADHD) and SPD465 (extended release triple-bead mixed amphetamine salts) (ADHD); Shire's ability to secure new products for commercialization and/or development; Shire’s planned acquisition of New River Pharmaceuticals announced February 20, 2007; and other risks and uncertainties detailed from time to time in Shire's and its predecessor registrant Shire Pharmaceuticals Group plc's filings with the Securities and Exchange Commission, particularly Shire plc’s Annual Report on Form 10-K for the year ended December 31, 2005.

Registered in England 2883758 Registered Office as above