Gilead Receives Complete Response Letters from U.S. Food and Drug Administration for Elvitegravir and Cobicistat

  Gilead Receives Complete Response Letters from U.S. Food and Drug
  Administration for Elvitegravir and Cobicistat

Business Wire

FOSTER CITY, Calif. -- April 29, 2013

Gilead Sciences, Inc. (Nasdaq: GILD) today announced that the company has
received Complete Response Letters from the U.S. Food and Drug Administration
(FDA) for its New Drug Applications (NDAs) for elvitegravir and cobicistat for
use as part of HIV treatment regimens.

In its communications, FDA states that it cannot approve the applications in
their current forms. The letters state that during recent inspections,
deficiencies in documentation and validation of certain quality testing
procedures and methods were observed. Gilead is working with FDA to address
the questions raised in the Complete Response Letters and move the
applications forward.

Elvitegravir and cobicistat are also components of Gilead’s once-daily single
tablet HIV-1 regimen Stribild^® (elvitegravir 150 mg/cobicistat 150
mg/emtricitabine 200 mg/tenofovir disoproxil fumarate 300 mg), which was
approved by FDA in August 2012 for treatment-naïve adults. This regulatory
action does not affect the marketing authorization or continued use of
Stribild.

Gilead submitted its NDAs for elvitegravir and cobicistat in June 2012.
Marketing applications are also pending in Europe.

About Elvitegravir

Elvitegravir is a member of the integrase inhibitor class of antiretroviral
compounds. Integrase inhibitors block the ability of HIV to integrate into the
genetic material of human cells. Elvitegravir was licensed by Gilead from
Japan Tobacco Inc. (JT) in March 2005. Under the terms of Gilead’s agreement
with JT, Gilead has exclusive rights to develop and commercialize elvitegravir
in all countries of the world, excluding Japan, where JT retains rights.

About Cobicistat

Cobicistat is Gilead’s proprietary potent mechanism-based inhibitor of
cytochrome P450 3A (CYP3A), an enzyme that metabolizes drugs in the body.
Unlike ritonavir, cobicistat acts only as a pharmacoenhancing or “boosting”
agent and has no antiviral activity.

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 Asia Pacific.

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 the risk that we may be
unable to remedy the deficiencies cited by the FDA in the Complete Response
Letters on a timely basisand that our inability to address those deficiencies
could adversely impact currently marketed products and products in
development. There is also the risk that health authorities in other countries
where applications are pending will undertake similar additional reviews which
could delay the approval of such products in those countries. 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, 2012, 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.

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

         Stribild is a registered trademark of Gilead Sciences, Inc.

For more information on Gilead Sciences, please visit the company’s website at
  www.gilead.com, follow Gilead on Twitter (@GileadSciences) or call Gilead
             Public Affairs at 1-800-GILEAD-5 or 1-650-574-3000.

Contact:

Gilead Sciences, Inc.
Patrick O’Brien, 650-522-1936 (Investors)
Erin Rau, 650-522-5635 (Media)