Merrill LynchGLOBAL DRUG, BIOTECH & MEDICAL

DEVICES CONFERENCE 2004

Gordon NganShire Pharmaceuticals Group

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THE “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 on Shire’s Attention Deficit 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 lanthanum carbonate (FOSRENOL®), methylphenidate (METHYPATCH®), anagrelide hydrochloride (XAGRID®), carbamazepine(BIPOTROL®) mesalamine (PENTASA® 500mg) and the adult indication for extended release mixed amphetamine salts (ADDERALL XR), the implementation of the planned reorganization and other risks and uncertainties detailed from time to time in Shire’s filings with the Securities and Exchange Commission.

The following are trademarks of Shire or companies within the Shire Group, which are the subject of trademark registrations in certain territories: ADDERALL XR® (mixed amphetamine salts), AGRYLIN® (anagrelide hydrochloride), BIPOTROL® (carbamazepine), CARBATROL® (carbamazepine), FOSRENOL® (lanthanum carbonate), METHYPATCH®

(methylphenidate), PROAMATINE® (midodrine hydrochloride),TROXATYL® (troxacitabine), XAGRID® (anagrelide hydrochloride).

The following are trademarks of third parties: 3TC® (trademark of GlaxoSmithKline (GSK)), PENTASA® (trademark of FerringAS), REMINYL® (trademark of Johnson & Johnson), ZEFFIX® (trademark of GSK), STRATTERA® (trademark of Eli Lilly)

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Agenda

Recent Business HighlightsShire Therapeutic Areas

RenalGI (Inflammatory Bowel Disease)CNS (ADHD)

Shire R&D ActivitiesRecent Financial HighlightsConclusion

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Business HighlightsStrong second quarter:

upgrade earnings for continuing operations growth in excess of 20% for 2004*

ADDERALL XR Adult approved by the FDA 12 August 2004FOSRENOL

US PDUFA date extended to 26 October 2004No safety and efficacy issue raised in FDA letterPre-launch preparation underwayUS launch planned for December 2004EU: further approvals are expected by end of 2004Strong composition of matter patent coverage until 2016

PENTASA 500mg anticipated launch Q3 2004TROXATYL global research, development and marketing rights out-licensed to Structural GenomiX Inc.Sales of vaccines business to ID Biomedical completedFour projects in development (two in Phase III and two in Phase II), and four in registration

*This is a non-GAAP financial measure. Management believes that the presentation of this non-GAAP financial measure provides useful information to investors regarding Shire’s underlying performance as the costs associated with the reorganization, the gain on the sale of an investment and the impact of the discontinued operations are not part of the Company’s ongoing operations.

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RenagelRenagel®® PhosLoPhosLo®®

OTC calciumOTC calcium

$278 Million(MAT June, 2004)

Market Profile455,000

410,000

Diagnosed Treated

US Renal Data System, 2002

RenalRenalRenal

End Stage Renal Disease in the U.S.*End Stage Renal Disease in the U.S.*

U.S. Dialysis Patient – Diagnosed and Treated

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RenagelRenagel®® PhosLoPhosLo®®

OTC calciumOTC calcium

$800 MillionPotential

$800 MillionPotential

455,000410,000

Diagnosed Treated

US Renal Data System, 2002

$278 Million(MAT June, 2004)

RenalRenalRenal

U.S. Dialysis Patient – Diagnosed and Treated Market Profile

End Stage Renal Disease in the U.S.*End Stage Renal Disease in the U.S.*

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RenalRenal

Fosrenol®Hyperphosphatemia in ESRD

Improved binding capacitySelective for phosphate = High PotencyImproved complianceChewable tablet reduces water intake

New clinical guidelines support adoptionAggressive phosphate reduction goalCalcium being restricted

Prescribing audience readily coveredPatent protection through 2016

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Inflammatory Bowel Disease in the United States*

500,000

600,000

Ulcerative Colitis Crohn’s Disease

Prevalence Treated

500,000500,000

*Crohn’s and Colitis Foundation of America, 2001

5-ASA / IBD

10.3%$ GrowthAugust 2003 - July 2004

$729 Million$ MarketAugust 2003 - July 2004

Gastrointestinal - IBDGastrointestinal Gastrointestinal -- IBDIBD

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Gastrointestinal Gastrointestinal -- IBDIBD

Pentasa (mesalamine)

Treatment for Ulcerative Colitis75% of Rxs for Crohn’s disease (U.S.)DACON: 12 caps x 250 mg / day

Pentasa 500mg ApprovedReduce to 6 caps / dayGreater convenience and complianceOpportunity for growth

Dissolution in stomach Small intestine Terminal ileum

Ascending colon Large intestine Large intestine

Time post dose: 0.22 hours 1.92 hours 6.33 hours

Time post dose: 10.57 hours 15.53 hours 24 hours

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3.5 hr ileum 4.5 hr Ascending colon

16 hr Descending Colon 24hr Rectum

Gastrointestinal Gastrointestinal -- IBDIBD

SPD 476 (mesalamine)

Treatment for Ulcerative ColitisNovel matrix formulation targets colon (“Fit” with PENTASA)High strength tablet form (1.2 g)Potential for QD dosing

Positive Phase II Study / Phase III OngoingNDA submission target 2005

Patent protection through 2020

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ADHD Market Potential

Prevalence Diagnosed TreatedPrevalence Diagnosed Treated

Pediatric Patients*

Million

Adult Patients*

8.2

4.8

.63

1.8

.60

1.7

*National Institute for Mental Health, 1999

ADHDADHD

39%$ GrowthAugust 2003 – July 2004

20%Growth in RxAugust 2003 – July 2004

$2.43 Billion$ MarketMAT July 2004

CNS - ADHDCNS CNS -- ADHDADHD

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Effective symptom control in the afternoon / evening

Non stimulant alternative to Amphetamines and Methylphenidate with substantial efficacy

Idiosyncratic therapeutic responses => Need for variety of pharmacological options

Current Medical Needs

CNS - ADHDCNS CNS -- ADHDADHD

SPD465 (ADDERALL XR2)

SPD503 (guanfacine)

SPD485 (METHYPATCH)

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CNS CNS -- ADHDADHD

AdultAdolescentPediatric

Amphetamine – TD

SPD485 (METHYPATCH)

Methylphenidate:

SPD503 (guanfacine)

Non-Stimulant:

SPD465 (ADDERALL XR2)

ADDERALL XR, Adult

Amphetamine:

Shire ADHD Portfolio

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CNS CNS -- ADHDADHD

SPD 503 (guanfacine)

Differentiated mechanism of action in ADHD Novel formulation of a non-scheduled compoundProvide second entry in growing “non-stimulant” segmentPatent protection through 2015 NDA filing: H1 / 2005

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CNS CNS -- ADHDADHD

SPD485 (METHYPATCH)SPD485 (METHYPATCH)

First transdermal drug delivery product for ADHDSmooth deliveryLong duration of effectFlexibility of “wear time”

Patent protectionTechnology platform: 2012Formulation: 2018

NDA supplement: H1 / 2005

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R&D Activities – CNS

ADDERALL XR Adult indication US - indication approved on 12 August 2004Adult indication Canada - sNDS submitted April 2004Pediatric Written Request - activities on-track in support of response – if approved a further 6-month Hatch-Waxman exclusivity will be granted (April 2005)

SPD503 (guanfacine) 2nd Phase III study initiated April 2004SPD485 (METHYPATCH) Clinical program agreed with FDA, initiated in May 2004 SPD465 (ADDERALL XR2) Phase II ongoing BIPOTROL – US PDUFA date 13 December 2004

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R&D Activities – GI

PENTASA 500mg launch planned for Q3 2004

SPD476 (mesalamine) filing on track for 2005

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R&D – Renal Diseases

FOSRENOL US PDUFA date 26 October 2004No safety and efficacy issue raised in FDA letterApproved in RMS (Sweden)

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Key Projects Flow

2005SPD465 (ADHD)

TBDSPD480 (UC)

2005SPD476 (UC)

2005SPD503 (ADHD)

BIPOTROL (Bipolar)

METHYPATCH (ADHD)

XAGRID (EU)

FOSRENOL (US/EU)

RegPIIIPII

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Financial Highlights – Q2 2004

-1.8246cInterim dividend:Cents (one pence) per ordinary share

42.6c55.2cADS

Non GAAP EPS (diluted)*:

+30%14.2c18.4cOrdinary shares

+23%72.789.5Income from continuing operations

(7.2)(55.5)Loss from discontinued operations

+27%99.4126.6Income from continuing operations before taxes

38.4c20.4cADS6.8c

34.0

110.2321.0

Q2 2004

+7%+ 8%

12.8c

65.5

102.6298.2

Q2 2003

EPS (diluted):Ordinary shares

Net Income

Operating incomeRevenues

Millions of US$, except per share amounts

*This is a non-GAAP financial measure. Management believes that the presentation of this non-GAAP financial measure provides useful information to investors regarding Shire’s underlying performance as the costs associated with the reorganization, the gain on the sale of an investment and the impact of the discontinued operations are not part of the Company’s ongoing operations. A reconciliation of this non-GAAP financial measure to the US GAAP financial measure can be found later in this presentation.

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Non-GAAP measures – Q2 2004

Reconciliation of reported EPS excluding certain transactions:

55.2c

7.8c

26.4c6.9c (6.3c)

20.4c

Per ADS

Q2 2004

18.4c

2.6c

8.8c2.3c

(2.1c)

6.8c

Per ORDS

Q2 2004

91.9

Diluted EPS excluding reorganization costs, discontinued operations and gain on sale investment

13.1

44.211.3

(10.7)

Reorganization costs, net of taxDiscontinued operations- loss on disposal- operational loss for Q2 2004

Gain on sale of investment, net of tax

Add back:

34.0Diluted EPS (as reported)

$mQ2 2004

NB: 1 ORD = 3 ADS

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Non-GAAP measures – 6 months to June 30, 2004Reconciliation of reported EPS excluding certain transactions:

180.8

15.9

44.220.1

(10.7)

111.2

$mH1 2004

104.7c

9.3c

25.5c11.7c (6.3c)

64.5c

Per ADS

H1 2004

34.9c

3.1c

8.5c 3.9c

(2.1c)

21.5c

Per ORDS

H1 2004

175c

Diluted EPS excluding reorganization costs,discontinued operations and gain on sale ofinvestment

-

-12c

-

Reorganization costs (net of tax)Discontinued operations- loss on disposal- operational loss for H1 2004

Gain on sale of investment (net of tax)

Add back:

163c Diluted EPS (as reported)

Per ADS

FY 2003

NB: 1 ORD = 3 ADS

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Balance Sheet

* Cash and cash equivalents, restricted cash and marketable securities

Millions of US$

1,534

1,158

2,004

31.03.04

1,628

1,251

2,022

30.06.04

1,414

1,038

1,923

31.12.03

Gross cash*

Net cash

Net assets

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Conclusion

Solid franchises in growing, underserved marketsSignificant products in late-stage developmentStrong registration / commercialization capabilityQuality reputation among high-prescribing, specialist MDs

Highly productive and flexible sales force

Track record of impressive financial performanceStrong balance sheet/cash position