SHIRE PLC: SHIRE ANNOUNCES FILING OF SPD465

SHIRE ANNOUNCES FILING OF SPD465 FOR THE TREATMENT OF ADULT ADHD        

Basingstoke, UK and Philadelphia, US - July 21, 2006 - Shire plc (LSE: SHP,
NASDAQ: SHPGY, TSX: SHQ) announced today that it has submitted a new drug
application (NDA) to the U.S. Food and Drug Administration (FDA) for SPD465, an
investigational amphetamine compound for the treatment of Attention-Deficit/
Hyperactivity Disorder (ADHD) in the adult population. The application is
subject to a 12-month FDA review period. SPD465 has the same active ingredient
as ADDERALL XR® (mixed salts of a single-entity amphetamine product), but is
designed to provide ADHD symptom control for up to 16 hours. Upon approval,
this novel product will be the first and only ADHD stimulant product that
controls inattention, hyperactivity and impulsivity for up to 16 hours.

"The FDA filing for SPD465 is another milestone met and underscores Shire's
commitment to be the market leader in ADHD treatments by offering patients new
solutions to manage this chronic disorder," said Matthew Emmens, Shire Chief
Executive Officer. "If approved, the 16-hour formulation of SPD465 would make
it the longest-acting stimulant medication for adult patients with ADHD, while
also providing the efficacy of ADDERALL XR, the most prescribed brand of ADHD
treatment."

ADHD is a neurological brain disorder that manifests as a persistent pattern of
inattention and/or hyperactivity-impulsivity that is more frequent and severe
than typically observed in individuals at a comparable age and maturity level.
Scientists now agree that up to 65 percent of adolescents with ADHD will
continue to have the ADHD diagnosis as adults. More than 9 million American
adults currently exhibit symptoms of ADHD, based on independent research by the
National Institute of Mental Health. Approximately 36 percent of ADHD
prescriptions are currently written for adult patients.

For further information on ADHD please visit www.adderallxr.com, 
www.adhdsupport.com, www.CHADD.org or www.NMHA.org.

For further information please contact:

Investor Relations  Cléa Rosenfeld (Rest of the World)       [phone]  
                                                                               
                    Brian Piper (North America)              [phone]   
                                                                               
Media               Jessica Mann (Rest of the World)         [phone]  
                                                                               
                    Matthew Cabrey (North America)           [phone]   

Notes to editors
About SPD465
SPD465, a mixed amphetamine salt formulation designed to provide sustained
release of medication and symptom control for up to 16 hours, is being studied
for the treatment of ADHD in adults. The most common adverse events reported in
SPD465 phase 3 studies were insomnia, decreased appetite and stomachache.

About ADDERALL XR

ADDERALL XR was generally well tolerated in clinical studies. The most common
side effects in studies included: children - decreased appetite, difficulty
falling asleep, stomachache, and emotional lability; adolescents - loss of
appetite, difficulty falling asleep, stomachache, and weight loss; adults - dry
mouth, loss of appetite, difficulty falling asleep, headache, and weight loss.

Tell your doctor about any heart conditions, including structural
abnormalities, that you, your child, or a family member, may have. ADDERALL XR
should not be taken by patients who are currently taking or have recently taken
a type of antidepressant called a MAO inhibitor, have a history of high blood
pressure, problems with alcohol or drugs, agitated states, or glaucoma.
Patients should also tell the doctor if they have seizures, visual
disturbances, thyroid problems, abnormal thoughts/behaviors, bipolar disorder,
depression, or other mental illness, or a known allergy to this type of
medication.

Abuse of amphetamines may lead to dependence. Misuse of amphetamine may cause
sudden death and serious cardiovascular adverse events. These events have also
been reported rarely with amphetamine use. Aggression, new abnormal thoughts/
behaviors, mania, and growth suppression have been associated with use of drugs
of this type. There is a potential for worsening of motion or verbal tics and
Tourette's syndrome. Report any new psychological symptoms to the doctor and
inform the doctor immediately of any symptoms that suggest heart problems, such
as chest pain or fainting.

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 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
plc'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 plc's Attention Deficit and
Hyperactivity Disorder ("ADHD") franchise; patents, including but not limited
to, legal challenges relating to Shire plc's ADHD franchise; government
regulation and approval, including but not limited to the expected product
approval dates of SPD503 (ADHD), SPD465 (ADHD), MESAVANCE TM (SPD476)
(ulcerative colitis), ELAPRASE TM (I2S) (Hunter syndrome) and NRP104 (ADHD),
including its scheduling classification by the Drug Enforcement Administration
in the United States; Shire plc's ability to benefit from the acquisition of
Transkaryotic Therapies Inc.; Shire plc's ability to secure new products for
commercialization and/or development; and other risks and uncertainties
detailed from time to time in Shire plc's and its predecessor registrant Shire
Pharmaceuticals Group plc's filings with the US Securities and Exchange
Commission, including Shire plc's Annual Report on Form 10-K for the year ended
December 31, 2005.

                                     # # #                                     

Adderall XR® is a registered trademark of companies within the Shire group.

Diagnostic and Statistical Manual of Mental Disorders is a registered trademark
of the American Psychiatric Association.


Hampshire International Business Park             
                                                  
Chineham Basingstoke                              
                                                  
Hampshire RG24 8EP                                
                                                  
United Kingdom                                    
                                                  
Tel [phone]                           
                                                  
Fax [phone]                           
                                                  
www.shire.com                                     
                                                  
Press Release                                     



END