Gilead Grants Intellectual Property Rights for Tenofovir Topical Gel to the International Partnership for Microbicides and CONRAD.

FOSTER CITY, Calif. & SILVER SPRING, Md. & ARLINGTON, Va. -- Gilead Sciences, Inc. (Nasdaq:GILD), the International Partnership for Microbicides (IPM) and CONRAD today announced an agreement under which Gilead has granted rights to IPM and CONRAD to develop, manufacture and, if proven efficacious, arrange for distribution in resource-limited countries of tenofovir as a microbicide to prevent infection with HIV, the virus that causes AIDS.

There are currently several microbicide candidates in clinical development designed to prevent HIV transmission and possibly other sexually transmitted infections. Tenofovir gel has previously been evaluated in a Phase I study, and Phase II studies are being conducted through the National Institutes of Health's HIV Prevention Trials Network.

"We are grateful to Gilead for their leadership in the development of microbicides for women," said Dr. Zeda Rosenberg, Chief Executive Officer of the International Partnership for Microbicides. "Tenofovir has a successful track record as a therapeutic, and an excellent safety profile. We are pleased to be working with CONRAD, the NIH and the US Agency for International Development to further study tenofovir as a microbicide candidate. IPM and CONRAD will also investigate tenofovir in combination with other antiretroviral agents."

Under the terms of the agreement, Gilead will provide to both IPM and CONRAD a royalty-free license to develop and, if proven efficacious, distribute tenofovir as a microbicide in approximately 100 resource-limited countries hardest hit by the HIV epidemic. Gilead will also facilitate the manufacturing of tenofovir by third-party contract manufacturers to supply ongoing clinical studies for two years, after which time other suppliers, including generic manufacturers, may be utilized.

As a female-initiated technology, microbicides could fill an important prevention gap for women who are unable to successfully negotiate mutual monogamy, condom use, or other safer sex practices. According to the latest UN report on the global AIDS epidemic, in every region of the world more women than ever before are living with HIV/AIDS. The 17.7 million women living with HIV/AIDS in 2006 represent an increase of over one million compared with 2004, making the need for female-initiated prevention tools especially urgent.

"Collaboration within the microbicide field is crucial to our eventual success," said Dr. Henry Gabelnick, Executive Director of CONRAD. "It is through public-private partnerships and the combined expertise of organizations like CONRAD and IPM that we will get an effective microbicide quickly to the women who urgently need this technology."

"The International Partnership for Microbicides and CONRAD have broad expertise in the development of microbicides for the potential prevention of HIV," said John C. Martin, PhD, President and CEO, Gilead Sciences. "Their knowledge and leadership will help ensure the appropriate clinical studies to evaluate the potential of tenofovir as a microbicide advance as quickly as possible."

Tenofovir was discovered through a collaborative research effort between Dr. Antonin Holy, Institute of 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. The inventors have agreed to waive their right to a royalty on sales of products containing tenofovir in the 97 developing countries served by the Gilead Access Program to ensure the product can be offered at a no-profit price in parts of the world where the AIDS epidemic has hit the hardest.

About IPM

IPM was established in 2002 to accelerate the development and accessibility of microbicides to prevent the transmission of HIV in women. By screening compounds, designing optimal formulations, establishing manufacturing capacity, developing trial sites and conducting efficacy trials, the organization works to improve the efficiency of all efforts to develop and deliver safe and effective microbicides as soon as possible. More information on IPM is available at www.ipm-microbicides.org.

About CONRAD

CONRAD is a cooperating agency of USAID committed to improving reproductive health by expanding the contraceptive choices of women and men and by helping to prevent the transmission of HIV/AIDS and other sexually transmitted diseases. CONRAD is administered through the Department of Obstetrics and Gynecology at Eastern Virginia Medical School (EVMS) in Norfolk, VA, with the main office located in Arlington, VA. More information on CONRAD is available at www.conrad.org.

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. For more information on Gilead, please visit us at www.gilead.com.

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 that 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 the Gilead Annual Report on Form 10-K for the year ended December 31, 2005, 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.