Investor Presentation Slides

Gilead to Acquire Pharmasset

November 21, 2011

Exhibit 99.2

Slide 2

Safe Harbor Disclaimer

Statements included in this presentation that are not historical in nature are “forward-looking statements” within the

meaning of the Private Securities Litigation Reform Act of 1995. Gilead cautions readers that forward-looking

statements are subject to certain risks and uncertainties, which could cause actual results to differ materially. These

risks and uncertainties include: Gilead’s ability to consummate the acquisition of Pharmasset and advance

Pharmasset’s product pipeline as planned; Gilead’s ability to successfully develop its HCV franchise; Gilead’s ability to

develop an all oral antiviral regimen for HCV; and Gilead’s ability to achieve its anticipated full year 2011 financial

results. Gilead directs readers to its Quarterly Report on Form 10-Q for the third quarter ended September 30, 2011

and subsequent current reports on Form 8-K. Gilead claims the protection of the Safe Harbor contained in the Private

Securities Litigation Reform Act of 1995 for forward-looking statements. All forward-looking statements are based on

information currently available to Gilead, and Gilead assumes no obligation to update any such forward-looking

statements.

This announcement is neither an offer to purchase nor a solicitation of an offer to sell shares of Pharmasset. At the

time the offer is commenced, Gilead will file a Tender Offer Statement on Schedule TO with the U.S. Securities and

Exchange Commission, and Pharmasset will file a Solicitation/Recommendation Statement on Schedule 14D-9 with

respect to the offer. Pharmasset stockholders and other investors are urged to read the tender offer materials

(including an Offer to Purchase, a related Letter of Transmittal and certain other offer documents) and the

Solicitation/Recommendation Statement because they will contain important information which should be read carefully

before any decision is made with respect to the tender offer. The Offer to Purchase, the related Letter of Transmittal

and certain other offer documents, as well as the Solicitation/Recommendation Statement, will be made available to all

stockholders of Pharmasset at no expense to them. The Tender Offer Statement and the Solicitation/Recommendation

Statement will be made available for free at the Commission's web site at www.sec.gov.

Slide 3

Agenda

Pharmasset Acquisition Highlights

HCV Landscape

Overview of Pharmasset HCV Portfolio

Gilead’s Combined HCV Opportunity

Page

Slide 4

Pharmasset Acquisition Highlights

Slide 5

Terms of the Agreement

Cash tender offer at $137 per share

Transaction value of approximately $11 billion

Tender offer expected to close within Q1 12

–

Subject to minimum tender requirement

–

Hart-Scott-Rodino (antitrust) clearance

–

Other customary conditions

Slide 6

Strategic Rationale

Accelerates Gilead’s strategy to develop the first all-oral

regimen for the treatment of HCV

–

PSI-7977 is the most potent, advanced nucleotide in clinical development

–

Phase 3 clinical studies of PSI-7977 in combination with ribavirin open to

enrollment

–

Targeted U.S. FDA approval in 2014

Since HCV can be cured, it will be important to be first to

market with an all-oral, well-tolerated regimen

Opportunity for significant revenue growth and diversification in

2014 and beyond

–

Composition of matter patent protection for PSI-7977 into 2029

Pharmasset is a strategic fit with Gilead’s areas of operational

excellence

Slide 7

Fit with Gilead’s Areas of Operational Excellence

Established expertise and commitment to liver disease

Preclinical, clinical development and regulatory expertise

–

Developed and commercialized 5 HIV and 2 hepatitis products

–

Viread regulatory approvals in approximately 140 countries

–

Established team: Quad NDA filing in 6 weeks after last patient, last visit

Expertise in process research and development, and

established worldwide API and product manufacturing network

–

Developed 1 fixed-dose combination and 3 single-tablet regimens in HIV

–

Manufacture tenofovir DF at >110 metric tons per year

Established commercial operations in 23 countries worldwide,

with expanding presence in Asia

Slide 8

HCV Landscape

Slide 9

<1%

1-1.9%

2-2.9%

>3%

Not tested

HCV Prevalence in Core and Emerging Markets (M)

Global Prevalence of HCV is Estimated to be

160 Million Individuals

(1)

HCV Prevalence

(% of population)

Region

Japan

Europe

Other

Asia

Latin

America

All GT

2.9

3.7

0.6

6.7

70.8

5.4

GT1 (%)

73%

63%

70%

65%

39%

68%

EU-Core 5

Sources: 1) Lavanchy, et al. 2011. 2) Gilead Forecast (2011 prevalence estimate). 3) Cornberg, Sievert, and Kershenobich, et al 2011.

Country populations from 2009 World Bank estimates

Slide 10

Over

Million

Infected

Individuals

Major

Markets

(1)

with Fewer than 200,000 Treated per Year

Treated/

Year

182

Diagnosed

Prevalence

12,601

Patients in thousands

36%

4,524

1. Major markets include US, EU-5, Japan, Australia, Austria, Brazil, Denmark, Finland, Greece, Ireland, Norway, Poland, Portugal, Sweden, Switzerland, Turkey, Canada

Sources:

Prevalence

–

KantarHealth

Core-5

epidemiology

analysis

(2010),

NHANES

(1999-2006),

Armstrong

(2004),

Hepatology,

40(4:S1):176a,

Chak

(2011),

Liver

Intl.,

1090-1101,

Cornberg

(2011),

Liver

Intl.,

(s2),

31-60,

Kershenobich

(2011),

Liver

Intl.,

(s2),

18-29

Diagnosed

–

KantarHealth

Core-5

epidemiology

analysis

(2010),

Armstrong

(2004)

Hepatology,

40(4:S1):176a,

Culver

(2000),

Transfusion

40:1176

Treated

–

IMS

MIDAS

(2004

–

2009),

Synovate

chart

audits

(2007),

Roche

and

Schering

Plough

annual

reports

(2009)

HCV: A Significant Unmet Medical Need

Slide 11

IFN 24 Wk

IFN 48 Wk

IFN/RBV 24 Wk

IFN/RBV 48 Wk

(1998)

IFN/RBV 48 Wk

(2001)

PegIFN/RBV 48

PI +

PegIFN/RBV 48

Wk (2011)

13-19%

31-35%

38-43%

45-47%

54-63%

66-79%

IFN

24 Weeks

IFN

48 Weeks

IFN/RBV

24 Weeks

IFN/RBV

48 Weeks

1998

IFN/RBV

48 Weeks

2001

PegIFN/RBV

48 Weeks

Protease

Inhibitor +

PegIFN/RBV

24-48 Weeks

2011

HCV Treatment Evolution

IFN = Interferon

RBV = Ribavirin

PegIFN = Pegylated Interferon

FDA Approval of

Protease Inhibitors (PIs)

in May 2011

Slide 12

Challenges of Current PI-based Treatment Remains

Additional safety issues and exacerbation of side effects

(rash and anemia)

–

Discontinuation rates significantly increased on PIs

Lower response rates in sub-populations

(previous IFN/RBV non-responders, cirrhotics)

Burdensome for patients and practitioners

–

PIs dosed 2-3 times per day, plus ribavirin and a

self-administered injection

–

Time intensive adverse event management, complexity of

response guided therapy

Slide 13

Ultimate Goal in HCV Therapy

Once a day

Pan-genotype

No clinical resistance

No response guided therapy

Short duration

Safe with manageable

side effects

High cure rates

Suitable for all populations

Ideal HCV Therapy Most Likely Achieved

through a Combination of Two or More Drugs

Easier for doctors and

patients

Leads to increased

diagnosis and treatment

Potential to cure many

more patients

Lowers cost to healthcare

system due to prevention

of end-stage liver disease

Slide 14

2010

2011

2020

IFN Free Strategy

Ultimate Goal

The Evolution of HCV Therapy: 2010

Current Standard of

Care (SOC):

PEG + RBV

Combination

Oral Antivirals +

Shorter Course IFN

Broad Genotypic Oral

Antiviral Regimen

The First Antivirals

+ SOC to Improve

Response Rates

and Reduce

Duration

All Oral Antiviral

Regimen

IFN Sparing Strategy

Slide 15

Current Standard of

Care (SOC):

PEG + RBV

The First Antivirals

+ SOC to Improve

Response Rates

and Reduce

Duration

The Competitive Nature and Speed of Development

Have Significantly Accelerated the Timelines

Ultimate Goal

All Oral Antiviral

Regimen

IFN Free Strategy

2010

2011

2020

Broad Genotypic Oral

Antiviral Regimen

2014

Slide 16

Overview of Pharmasset HCV Portfolio

Slide 17

Pharmasset’s HCV Nucleotide Portfolio

PSI-7977

PSI-938

RG 7128

•

3.6 log HCV RNA

with 400 mg QD over 3 days

•

Phase 3 in combination with ribavirin

open to enrollment

•

Highest on treatment and SVR rates to date

•

Unpartnered with worldwide rights

•

3.6 log HCV RNA

with 300 mg QD over 3 days

•

Phase 2

•

14 day data, with ongoing 12 week studies

•

Unpartnered with worldwide rights

•

0.6 log HCV RNA

with 1gm BID

•

Phase 2b

•

Partnered with Roche

Slide 18

PSI-7977: Pharmasset’s Lead Pyrimidine

Nucleotide Analogue

Excellent safety profile

–

250 patients at 8 weeks or more

–

1,500 patients by May 2014

High rates of cure in genotype 2/3

–

100% (10/10) with ribavirin

–

60% (6/10) without ribavirin

Studies in genotype 1 ongoing

–

Expecting Phase 2 SVR12 data early 2012

Multiple expanding data sets from studies in different

patient populations

Slide 19

PSI-7977: Genotype 2/3 Phase 2 Results

(ELECTRON)

Time

(Weeks)

PSI-7977

RBV

12 weeks PEG

PSI-7977

RBV

NO PEG

PSI-7977

NO PEG

NO RBV

n/n (%) < LOD

8/11 (82%)

8/10 (80%)

11/11 (100%)

10/10 (100%)

11/11 (100%)

10/10 (100%)

SVR4

11/11 (100%)

10/10 (100%)

6/10 (60%)

SVR12

11/11 (100%)

10/10 (100%)

n/a

n/a –

not yet available

Slide 20

Pharmasset’s Phase 3 Program

(Announced November 1, 2011)

Genotype 2/3

(naïve)

Genotype 2/3

(IFN intolerant)

N=~250

N=~150

N=~75

SVR12

POSITRON

FISSION

PSI-7977 400mg

+ RBV

Peg-IFN + RBV

PSI-7977 400mg

+ RBV

PSI-7977 placebo

+ RBV placebo

third

Phase

study

initiated

genotype

patients

Targeted U.S. FDA approval in 2014

Slide 21

Key Remaining Questions in the Treatment of HCV

Will one regimen work for all genotypes or will different

regimens be required for different genotypes?

How many molecules or mechanisms do you need?

Can ribavirin be replaced?

What is the minimum duration of therapy?

Can HCV be cured with once-daily therapy?

Slide 22

Gilead’s Combined HCV Opportunity

Slide 23

Pharmasset and Gilead Combined HCV Efforts

Position Us to Answer These Questions

High barrier to resistance/pan-genotypic compounds will be an

important component for any all-oral regimen

–

Pharmasset’s PSI-7977 is the most advanced, pan-genotypic compound

with a high barrier to resistance

–

Ongoing efforts at Gilead to identify other pan-genotypic compounds

Complementary portfolio accelerates potential for oral regimens

–

Includes

direct

acting

antivirals

with

four

different

mechanisms

Phase

2/3 clinical development

–

Potential to pursue different combinations to then answer the question of

duration of treatment and necessity of ribavirin

Complementary portfolios cover a number of opportunities for

once-daily regimens

–

Potential for co-formulation

Slide 24

Phase

9451

(NS3

protease

inhibitor)*

5885

(NS5A

inhibitor)*

9620

(TLR-7

agonist)*

6620

(nucleotide

NS5B

inhibitor)**

9669

(non-nuc

NS5B

site

inhibitor)*

Combined HCV Clinical Portfolio

Once-daily dosing

III

PSI-7977

(nucleotide

NS5B

inhibitor)*

PSI-938

(nucleotide

NS5B

inhibitor)*

Pharmasset Acquisition

Complements and Accelerates

Gilead’s HCV Portfolio

9256

(NS3

protease

inhibitor)**

Tegobuvir/GS

9190

(non-nuc

NS5B

inhibitor)

No further clinical trials planned

Slide 25

All-Gilead Portfolio Increases the Chance of

Developing Oral Therapies across Genotypes

Nuc

NS5A

Non-Nuc

GS 5885

PSI-7977

PSI-938

GS 9451

GS 9190

GS 9669

Combination Therapies with High Potency May Further

Shorten Duration and Eliminate Ribavirin

Slide 26

2012 Key HCV Milestones

Initiate and integrate Pharmasset’s Phase 3 programs

–

GT 2/3 programs: no change

–

GT 1: Phase 2 data will determine strategy

Initiate clinical trial with PSI-7977 to define minimum

treatment duration in GT 2/3 patients

Initiate multiple enabling drug-drug interaction studies with

Gilead and Pharmasset assets

Explore combinations that exclude ribavirin

Initiate programs in pre-transplant and HIV co-infected

populations

SVR data from Gilead’s all-oral Phase 2 Study 120 at EASL

Slide 27

In Summary

Accelerates Gilead’s strategy to develop the first all-oral

regimen for the treatment of HCV

Since HCV can be cured, it will be important to be first to

market with an all-oral, well-tolerated regimen

Pharmasset is a strategic fit with Gilead’s areas of

operational excellence

Opportunity to change revenue trajectory starting in 2014

Slide 28

Gilead’s Business Prospects

Strong confidence in our core business

–

LTM HIV revenues of ~$6.4B in a total ~$13.0B market

–

LTM ~$1B in revenues coming from products outside HIV

Anticipate major HIV product launches in 2012

–

New revenue sources through partnerships to follow

More Phase 2/3 programs across therapeutic areas than

ever before

–

HIV, liver disease, oncology/inflammation/fibrosis, respiratory and

cardiovascular

Note: LTM = last twelve months

Slide 29

Financial Impact of Pharmasset Acquisition

Cash flows from core business will allow us to finance transaction

Expect to use existing cash and $6.2 billion in incremental debt

Committed to retaining investment grade credit rating

–

Debt/EBITDA ratio to return to

1.5x at closing + 1 year

Transaction expected to be dilutive initially and

significantly accretive beyond 2015

–

Increased interest expense associated with transaction debt

–

Share repurchases to offset dilution as debt is repaid

Slide 30

Transaction Summary

Unique opportunity to dramatically change HCV disease

burden worldwide

Potential to extend leadership in liver disease to HCV

Opportunity to parallel the commercial success in HIV

Redefined potential for revenue growth in 2014 and beyond

Gilead to Acquire Pharmasset

November 21, 2011