U.S. Food and Drug Administration Approves Viread(R) for Chronic Hepatitis B in Adults

[Guest guest]

http://www.gilead.com/pr_1186292

PRESS RELEASE

U.S. Food and Drug Administration Approves Viread® for Chronic Hepatitis B in

Adults

- Important New Treatment Option for Millions in United States

Affected by Life-Threatening Liver Disease -FOSTER CITY,

Calif.--(BUSINESS WIRE)--Aug. 11, 2008--Gilead Sciences, Inc. (NASDAQ:GILD)

today announced that the U.S. Food and Drug Administration (FDA) has granted

marketing approval for Viread® (tenofovir disoproxil fumarate) for the

treatment of chronic hepatitis B, a serious liver disease caused by the

hepatitis B virus (HBV). Chronic hepatitis B is the leading cause of liver

cancer worldwide and affects an estimated two million individuals in the United

States.

Viread is now also indicated for the treatment of chronic hepatitis B in adults.

The drug is administered as a once-daily tablet, and works by blocking HBV DNA

polymerase, the enzyme that is necessary for the virus to replicate in liver

cells. Viread has been available in the United States as a treatment for HIV

infection in adults since 2001.

" Viread will be an important new treatment option and its approval represents a

significant step forward in the fight against chronic hepatitis B, " said Ira

son, M.D., Chief, Division of Gastroenterology and Hepatology, Weill

Cornell Medical College.

Pivotal Clinical Trials

Today's approval is based on data from two ongoing, randomized and double-blind

Phase III clinical trials, Studies 102 and 103, which compared Viread to

Gilead's Hepsera® (adefovir dipivoxil) over 48 weeks of treatment. Results

from both studies show that a significantly greater percentage of patients with

chronic hepatitis B who received Viread achieved a complete response to

treatment compared to those who received Hepsera. A complete response was

defined as serum HBV DNA levels below 400 copies/mL and histologic improvement

characterized by at least a two point reduction in the Knodell necroinflammatory

score (a measure of necro-inflammation - an inflammatory process in the liver

including or leading to death of liver cells) with no concurrent worsening of

fibrosis (scarring of liver tissue). Trial participants included both patients

new to HBV therapy (n=375) and patients (n=51) who had received prior nucleoside

treatment. To date, more than 400 chronic hepatitis B patients have been treated

with Viread in these studies.

" The approval of Viread for hepatitis B represents more than a decade of work in

both the fields of HIV and hepatitis B to develop a medication that offers

significant viral suppression, once-daily dosing and a well-established safety

profile, " said Young, Executive Vice President, Commercial Operations,

Gilead Sciences. " We extend our thanks to the investigators and patients who

participated in the clinical trials that support today's approval, and we look

forward to partnering with community members to increase disease awareness and

expand access to treatment for those patients in need. "

Because chronic HBV infection can persist for years without causing any

noticeable symptoms, many people are unaware they are infected and do not seek

treatment. The disease disproportionately affects Asian Americans: One in 10

foreign-born Asian Americans is estimated to be living with chronic HBV

infection, a rate 100 times greater than that of the non-Asian U.S. population,

which reflects the high prevalence of HBV in many Asian countries.

" Although we've made great strides in reducing the overall incidence of chronic

hepatitis B in the United States, the disease still takes a devastating toll in

Asian-American communities, " said Danny Chu, M.D., Community Physician, New

York. " Greater public awareness and effective new treatment options are urgently

needed to help reduce this significant health disparity. "

The approval of Viread expands Gilead's hepatic health franchise. The company's

first treatment for chronic hepatitis B, Hepsera, is currently the most widely

prescribed oral agent for the disease in the United States. The company is also

developing small-molecule compounds for the treatment of hepatitis C and a

hepatoprotectant for multiple forms of hepatitis-related liver fibrosis,

including nonalcoholic steatohepatitis (also known as NASH).

Viread was approved for the treatment of chronic hepatitis B in the European

Union, Turkey, Australia and New Zealand earlier this year, and a marketing

application is currently pending in Canada.

Important Information About Viread for Chronic Hepatitis B

Viread (tenofovir disoproxil fumarate) is indicated for the treatment of chronic

hepatitis B in adults.

The following points should be considered when initiating therapy with Viread

for the treatment of HBV infection:

-- This indication is based on data from one year of treatment in

primarily nucleoside-treatment-naive adult patients with

HBeAg-positive and HBeAg-negative chronic hepatitis B with

compensated liver disease.

-- The numbers of patients in clinical trials who were

nucleoside-experienced or who had lamivudine-associated

mutations at baseline was too small to reach conclusions of

efficacy.

-- Viread has not been evaluated in patients with decompensated

liver disease.

The recommended dose for the treatment of chronic hepatitis B is 300 mg once

daily taken orally without regard to food. Dose interval adjustment is

recommended in renal impairment.

LACTIC ACIDOSIS/SEVERE HEPATOMEGALY WITH STEATOSIS AND POST TREATMENT

EXACERBATION OF HEPATITIS

Lactic acidosis and severe hepatomegaly with steatosis, including fatal cases,

have been reported with the use of nucleoside analogs alone or in combination

with other antiretrovirals.

Severe acute exacerbations of hepatitis have been reported in HBV-infected

patients who have discontinued anti-hepatitis B therapy, including Viread.

Hepatic function should be monitored closely with both clinical and laboratory

follow-up for at least several months in patients who discontinue anti-hepatitis

B therapy, including Viread. If appropriate, resumption of anti-hepatitis B

therapy may be warranted.

New onset or worsening of renal impairment including cases of acute renal

failure and Fanconi syndrome have been reported with the use of Viread. It is

recommended to assess creatinine clearance (CrCl) before initiating treatment

with Viread and monitor CrCl and serum phosphorus in patients at risk.

Administering Viread with concurrent or recent use of nephrotoxic drugs,

including Hepsera should be avoided.

HIV antibody testing should be offered to all HBV-infected patients before

initiating therapy with Viread. Viread should only be used as part of an

appropriate antiretroviral combination regimen in HIV-infected patients with or

without HBV coinfection.

Decreases in bone mineral density (BMD) have been observed in HIV-infected

patients. It is recommended that BMD monitoring be considered for patients with

a history of pathologic fracture or who are at risk for osteopenia. The bone

effects of Viread have not been studies in patients with chronic HBV infection.

In controlled clinical trials in patients with chronic hepatitis B, the most

common adverse reaction (all grades) is nausea. Other treatment-emergent adverse

reactions reported in greater than 5 percent of patients treated with Viread

included: abdominal pain, diarrhea, headache, dizziness, fatigue,

nasopharyngitis, back pain and skin rash.

About Chronic Hepatitis B

The hepatitis B virus (HBV) is up to 100 times more easily transmitted than HIV.

While most new cases of HBV infection in previously healthy adults are cleared

by the immune system within a few months, many people - especially those

infected as newborns and young children - will develop chronic, lifelong

infections. In these cases, chronic hepatitis B can slowly destroy the liver,

causing scarring (cirrhosis), liver disease, or liver cancer over many years or

decades. Because it is believed to be the cause of 80 percent of all liver

cancer cases worldwide, HBV is second only to tobacco among known human

carcinogens.

The hepatitis B virus can be transmitted by any activity that involves exposure

to blood and other body fluids, including sexual contact and use of contaminated

needles during injection drug use. It can also be transmitted from mother to

child at birth, which is the primary transmission route among Asian Americans.

Asian Americans are one of the fastest-growing minority groups in the United

States, numbering approximately 15 million people in 2007. A recent study showed

that up to two-thirds of Asian Americans with chronic hepatitis B did not know

they were infected.

Although there is no simple cure for chronic hepatitis B, antiviral treatment

can slow viral replication and therefore reduce liver inflammation and liver

injury.

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 City, California,

Gilead has operations in North America, Europe and Australia.

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 the risks that physicians may not

prescribe the product over existing HBV medications and regulatory agencies and

payers may be reluctant to approve or provide reimbursement for the product.

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 and its Quarterly Report on Form 10-Q for the

second quarter of 2008, 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.

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

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

Viread and Hepsera are registered trademarks 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.

CONTACT: Gilead Sciences, Inc.

Hubbard, 650-522-5715 (Investors)

Cara , 650-522-1616 (Media)

SOURCE: Gilead Sciences, Inc.