Second Quarter Resultsended 30 June 2004

Shire Pharmaceuticals Group plc

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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®) 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 Ferring AS), REMINYL® (trademark of Johnson & Johnson), ZEFFIX® (trademark of GSK).

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Agenda

Second Quarter 2004 - Business & R&D Highlights Matthew EmmensFinancial Review Angus RussellConclusion Matthew EmmensQuestions & Answers All

Matthew Emmens Chief Executive Officer

Second Quarter 2004Business and R&D Highlights

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Financial Highlights – Q2 2004

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

55.2cADS

Non GAAP EPS (diluted)*:

+30%18.4cOrdinary shares

+23%89.5Income from continuing operations

(55.5)Loss from discontinued operations

+27%126.6Income from continuing operations before taxes

20.4cADS6.8c

34.0

110.2321.0

Q2 2004

+7%+ 8%

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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Business Highlights

Strong second quarter:upgrade earnings for continuing operations growth in excess of 20% for 2004*

FOSRENOL 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.Vaccines development costs transferred to ID BiomedicalFive projects in development, two in Phase III and two in Phase II and five 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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R&D Activities – Central Nervous System

CNSADDERALL XR

Adult indication US - Next action date 13 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 - 2nd Phase III study initiated April 2004

METHYPATCH - Clinical program agreed with FDA, initiated in May 2004

SPD473 - Criteria for continued development in ADHD not met in the Proof of Concept study

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Development Activities – GI

GI

PENTASA 500mg launch planned for Q3 2004

SPD476 – Studies well underway, filing remains on track for 2005

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Development Activities – General Products

AGRYLIN/XAGRID6-month pediatric exclusivity extension granted through to mid-September 2004 in USCommittee for Medicinal Products for Human Use (CHMP) expected to re-confirm their positive opinion following completion of external data review

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Key Projects Flow

2005SPD465 (ADHD)

TBDSPD480 (UC)

2005SPD476 (UC)

2005SPD503 (ADHD)

BIPOTROL (Bipolar)

METHYPATCH (ADHD)

ADDERALL XR (adult)

XAGRID (EU)

FOSRENOL (US)

RegPIIIPII

Angus Russell Chief Financial Officer

Financial Review

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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

91.9c

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

13.1c

44.2c11.3c

(10.7c)

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

Gain on sale of investment, net of tax

Add back:

34.0cDiluted 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:

180.8c

15.9c

44.2c20.1c

(10.7c)

111.2c

$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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Major Product Sales – Q2 2004

Millions of US$

* Source: IMS Data

+2+724.826.4PENTASA

+14-1513.911.9CARBATROL

-7

+40

Growth (%)

+336.634.0AGRYLIN

+20102.4143.5ADDERALL XR

US Rx Growth (%)*

Q2 03Q2 04

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Other International Product Sales – Q2 2004

Millions of US$

86%0.71.3Adept

69%1.32.2Solaraze

43%1.42.0Colazide

17%1.82.1Lodine

12%2.52.8Reminyl

42%

Growth (%)

6.49.1Calciums

Q2 03Q2 04

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Royalty Income – Q2 2004

* Foreign exchange movements have contributed +4% to reported growth** Foreign exchange movements have contributed +5% to reported growth*** Includes REMINYL

Millions of US$

+11

+31

+19**

+6*

Reported Growth (%)

8.611.3Other ***

Q2 03 Royalties

Q2 04 Royalties

51.857.7Total

5.76.8ZEFFIX

37.539.63TC

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Financial Ratios for continuing operations

40

41

15

89

11

Q2 04

3534Operating margin

37

16

86

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FY03Q2 03

15R&D : Revenues

41S,G&A (excl. D&A) : Product sales

85Gross margin

15COGS : Product sales

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Cash Flow – Q2 2004

Millions of US$

Net cash surplus for Q2 2004 : $93 million

Cash generation + $137

Tax / interest- $36

Fixed assets + $2

+ $3Financing

Product acquisitions - $12

Discontinued operations - $23

Investment + $22

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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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Outlook

Revenue growth upgrade for 2004: high single digit range*Earnings for continuing operations upgraded to growth in excess of 20% for 2004**

Excludes internal re-organization / restructuring costs (approx 23 cents per ADS)

Q1 2004 include $3.8 million Q2 2004 include $18.2 million

Excludes $14.8 million gain on the sale of a portfolio investmentExcludes the vaccines business reported separately as “discontinued operation”

Beyond 2004EPS growth on average in mid teens rangeAim to maintain consistent operating margins

* Despite loss of exclusivity on PROAMATINE in Q3 2003 and AGRYLIN in the US in Q4 2004**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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Dividend

Dividend to be paid semi annually set in US cents per share / ADSFor 2004 approx one third / two third split of total annual dividend between the first and second interim dividend1.8246 cents (one pence) per ordinary share for six months ended 30 June 2004First Interim dividend to be paid on 14 October 2004Dividend will be paid based on exchange rates taken on or immediately before the date of resolution to:

ORD holders to receive payment in UK£ADS holders to receive an equivalent US$ dividend Exchangeable share holders to receive an equivalent C$ dividend

The Company intends to grow this dividend progressively

Matthew Emmens Chief Executive Officer

Concluding remarks

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Strong second quarterupgrade earnings for continuing operations to growth in excess of 20% for 2004*

FOSRENOLUS PDUFA date 26 October 2004Under treated disease, very attractive productGlobal launch plans underway

PENTASA 500mg anticipated launch Q3 2004TROXATYL global research, development and marketing rights out-licensed to Structural GenomiX Inc.

Vaccines development costs transferred to ID Biomedical

Five projects in development, two in Phase III and two in Phase II and five in registration

Concluding remarks

*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.

Questions and Answers