European CHMP Issues Positive Opinion for Viread(R) for the Treatment of Chronic Hepatitis B

Gilead Sciences, Inc. (Nasdaq: GILD) today announced that the
Committee for Medicinal Products for Human Use (CHMP) of the European
Medicines Agency (EMEA) has issued a positive opinion on the company´s
application to extend the indication for Viread(R) (tenofovir
disoproxil fumarate) to include the treatment of chronic hepatitis B
in adults. The application, known as a Type II variation, was
submitted to European regulatory authorities in October 2007.

The CHMP´s positive opinion will be forwarded to the European
Commission, which will amend the Marketing Authorisation for Viread in
the 27 countries of the European Union to reflect the Type II
variation. The European Commission generally issues an updated
Marketing Authorisation within a few months following a positive CHMP
recommendation. Viread represents Gilead´s second once-daily antiviral
developed for the potential treatment of chronic hepatitis B. The
active ingredient in Viread, tenofovir disoproxil fumarate, is the
most widely prescribed molecule for the treatment of HIV infection in
the United States and several countries of the EU.

"The complications associated with chronic hepatitis B make it a
leading cause of death worldwide," said Patrick Marcellin, MD, Hopital
Beaujon, Clichy, France. "In Europe, the incidence of chronic
hepatitis B is significant and growing, which underscores the
importance of increased screening and immunization for eligible
patients, and the need for safe and effective treatment options that
can slow or potentially even halt the progression of liver damage for
patients living with chronic hepatitis B."

The application is based primarily on data from two ongoing Phase
III clinical trials, Studies 102 and 103, in patients chronically
infected with the hepatitis B virus (HBV). These studies evaluate the
efficacy, safety and tolerability of Viread compared to adefovir
dipivoxil. Positive data from both studies were described in
late-breaker presentations at the annual meeting of the American
Association for the Study of Liver Diseases in November 2007.
Additional 72-week data from these studies will be presented at the
annual meeting of the European Association for the Study of the Liver
(EASL), taking place in Milan, Italy, April 23-27.

Gilead has also submitted applications for marketing approval of
Viread for hepatitis B in the United States, Australia, Canada, New
Zealand and Turkey.

About Chronic Hepatitis B

Chronic hepatitis B is a common and potentially fatal liver
disease caused by the hepatitis B virus, which is up to 100 times more
easily transmitted than HIV. Chronic hepatitis B can produce no
symptoms in its earlier stages so many individuals are unaware that
they are infected until they have advanced liver disease.
Complications commonly associated with chronic hepatitis B include
scarring of the liver (cirrhosis), liver failure and liver cancer.
More than 400 million people are estimated to be chronically infected
with HBV worldwide and, without treatment, up to one quarter of those
will ultimately die of liver disease.

About Viread (tenofovir disoproxil fumarate) for HIV

In the United States, Viread is indicated in combination with
other antiretroviral agents for the treatment of HIV-1 infection.

Lactic acidosis and severe hepatomegaly with steatosis, including
fatal cases, have been reported with the use of nucleoside analogues
alone or in combination with other antiretrovirals. Viread is not
approved for the treatment of chronic hepatitis B virus (HBV)
infection and the safety and efficacy of Viread have not been
established in patients coinfected with HBV and HIV. Severe acute
exacerbations of hepatitis B have been reported in patients who have
discontinued Viread. Hepatic function should be monitored closely with
both clinical and laboratory follow-up for at least several months in
patients who are co-infected with HIV and HBV and discontinue Viread.
If appropriate, initiation of anti-hepatitis B treatment may be
warranted.

It is important for patients to be aware that anti-HIV medicines
including Viread do not cure HIV infection or AIDS, and do not reduce
the risk of transmitting HIV to others.

Renal impairment, including cases of acute renal failure and
Fanconi syndrome (renal tubular injury with severe hypophosphatemia),
has been reported in association with the use of Viread. It is
recommended that creatinine clearance be calculated in all patients
prior to initiating therapy with Viread and as clinically appropriate
during therapy. Routine monitoring of calculated creatinine clearance
and serum phosphorous should be performed in patients at risk for
renal impairment. Dosing interval adjustment and close monitoring of
renal function are recommended in all patients with creatinine
clearance less than 50mL/min. Viread should be avoided with concurrent
or recent use of a nephrotoxic agent.

The U.S. package insert advises that co-administration of Viread
and didanosine should be undertaken with caution. Patients should be
monitored closely for didanosine-associated adverse events and
didanosine should be discontinued if these occur. Patients on
atazanavir and lopinavir/ritonavir plus Viread should be monitored for
Viread-associated adverse events and Viread should be discontinued if
these occur. When co-administered with Viread, it is recommended that
atazanavir be given with ritonavir 100 mg. Atazanavir without
ritonavir should not be co-administered with Viread.

Decreases in bone mineral density (BMD) at the lumbar spine and
hip have been seen with the use of Viread. The effect on long-term
bone health and future fracture risk is unknown. Cases of osteomalacia
(associated with proximal renal tubulopathy) have been reported in
association with the use of Viread.

Changes in body fat have been observed in patients taking anti-HIV
medicines. The mechanism and long-term health effect of these changes
are unknown. Immune Reconstitution Syndrome has been reported in
patients treated with combination therapy, including Viread.

The most common adverse events among patients receiving Viread
with other antiretroviral agents in a pivotal clinical study (Study
903) were mild to moderate gastrointestinal events and dizziness.
Moderate to severe adverse events occurring in more than 5 percent of
patients receiving Viread included rash (rash, pruritis, maculopapular
rash, urticaria, vesiculobullous rash and pustular rash), headache,
pain, diarrhea, depression, back pain, fever, nausea, abdominal pain,
asthenia (weakness) and anxiety. In another pivotal study (Study 907),
less than 1 percent of patients discontinued participation because of
gastrointestinal events.

Full prescribing information for Viread in the United States is
available at www.Viread.com. For full prescribing information outside
of the United States physicians should consult their local product
labeling.

The parent compound of Viread was discovered through a
collaborative research effort between Dr. Antonin Holy, Institute for
Organic Chemistry and Biochemistry, Academy of Sciences of the Czech
Republic (IOCB) in Prague and Dr. Erik DeClercq, Rega Institute for
Medical Research, Katholic University in Leuven, Belgium.

About Gilead Sciences

Gilead Sciences is a biopharmaceutical company that discovers,
develops and commercializes innovative therapeutics in areas of unmet
medical need. The company´s mission is to advance the care of patients
suffering from life-threatening diseases worldwide. Headquartered in
Foster City, California, Gilead has operations in North America,
Europe and Australia.

Forward-Looking Statement

This press release includes forward-looking statements, within the
meaning of the Private Securities Litigation Reform Act of 1995, that
are subject to risks, uncertainties and other factors, including risks
that regulatory authorities may not approve Viread for the treatment
of chronic hepatitis B in the United States or European Union, and
marketing approval, if granted, may have significant limitations on
its use. These risks, uncertainties and other factors could cause
actual results to differ materially from those referred to in the
forward-looking statements. The reader is cautioned not to rely on
these forward-looking statements. These and other risks are described
in detail in Gilead´s Annual Report on Form 10-K for the year ended
December 31, 2007, as filed with the U.S. Securities and Exchange
Commission. All forward-looking statements are based on information
currently available to Gilead, and Gilead assumes no obligation to
update any such forward-looking statements.

Viread is a registered trademark of Gilead Sciences, Inc.

For more information on Gilead, please call the Gilead Public
Affairs Department at 1-800-GILEAD-5 (1-800-445-3235) or visit
www.gilead.com