European Commission Approves Viread(R)
for Chronic Hepatitis B

Important New Treatment Option for Millions of Europeans Affected by Life-Threatening Disease

FOSTER CITY, Calif. -- April 25, 2008 -- Gilead Sciences, Inc. (NASDAQ:GILD) today announced that the European Commission has granted marketing authorisation for Viread(R) (tenofovir disoproxil fumarate) for the treatment of chronic hepatitis B in all 27 member states of the European Union.

A once-daily tablet, Viread works by blocking hepatitis B virus (HBV) DNA polymerase, the enzyme that is necessary for the virus to replicate in liver cells. Viread has been approved in the European Union for use in adult chronic HBV patients with compensated liver disease, with evidence of active viral replication, persistently elevated serum alanine aminotransferase (ALT) levels and histological evidence of active inflammation and/or fibrosis. The product was recently approved for the treatment of chronic hepatitis B in Turkey and New Zealand, and marketing applications are currently pending regulatory review in the United States, Canada and Australia.

"Hepatitis B is a significant problem in Europe, where approximately 20,000 people die of complications from the disease each year," said Patrick Marcellin, MD, PhD, Professor of Hepatology at the University of Paris and Head of the Viral Hepatitis Research Unit (INSERM) at the Hopital Beaujon in Clichy, France. "As a physician and researcher who has studied this drug extensively in large-scale clinical trials, I believe Viread is an important treatment option for patients who are just starting therapy, as well as for those who may have had previous experience with other medications, including lamivudine."

Today's approval is based primarily on data from two ongoing Phase III clinical trials, Studies 102 and 103, in patients (n = 375) chronically infected with HBV who were new to HBV therapy (treatment-naive). Some patients (n=51) in the Phase III trials have had previous experience with lamivudine (treatment-experienced). These studies evaluate the efficacy, safety and tolerability of Viread compared to Hepsera(R) (adefovir dipivoxil). Positive data from these studies were presented in late-breaker presentations at the annual meeting of the American Association for the Study of Liver Diseases in Boston, Massachusetts, November 2007. Additional 72-week data from these studies were presented at the annual meeting of the European Association for the Study of the Liver in Milan, Italy, April 23-27.

"Data from studies 102 and 103 demonstrate that Viread has many of the preferred qualities of an antiviral treatment: rapid and profound viral suppression, a well-established safety profile with more than one million years of patient experience, and convenient once-daily administration," said Kevin Young, Executive Vice President, Commercial Operations at Gilead Sciences. "Now that Viread is approved for chronic hepatitis B in Europe, our top priority is working to ensure that all individuals who need the medication have access to it as quickly as possible."

Viread represents Gilead's second once-daily antiviral for the treatment of chronic hepatitis B; the first, Hepsera, is currently widely used as a treatment for chronic hepatitis B in Europe. In addition, the company is also developing small molecule compounds for the treatment of hepatitis C and a hepatoprotectant for hepatitis-related liver fibrosis.

Viread has been available in Europe as a part of combination therapy for HIV infection in adults since 2002. Its active ingredient, tenofovir disoproxil, is the most widely prescribed molecule for the treatment of HIV infection in several European Union nations.

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.

U.S. full prescribing information for Viread is available at www.Viread.com

U.S. full prescribing information for Hepsera is available at www.Hepsera.com