Gilead Sciences Announces Changes in Senior Management Team

Foster City, CA -- February 17, 2000

Gilead Sciences, Inc. (Nasdaq: GILD) announced today a series of changes in its senior management team. Jeffrey W. Bird, who joined Gilead in 1988 and has served as Senior Vice President, Business Operations since January 1998, is leaving Gilead to join Three Arch Partners, a venture capital firm. Mark L. Perry, who joined Gilead in 1994 and currently serves as Senior Vice President, Chief Financial Officer and General Counsel, will become Senior Vice President, Operations. In his new role, Mr. Perry will manage the business operations of the Company, including sales and marketing, as well as his current areas of responsibility. Sharon Surrey-Barbari, Gilead’s Vice President of Finance, will become Chief Financial Officer, reporting to Mr. Perry.

Norbert W. Bischofberger, Ph.D., Senior Vice President, Research & Development, will be responsible for Gilead’s antiviral clinical development programs, as well as pharmaceutical product development and the Company’s research and drug discovery activities. William A. Lee, Ph.D., who joined Gilead in 1991 and currently serves as Vice President, Pharmaceutical Product Development, will now report to Dr. Bischofberger and assume additional responsibility for the Company’s research activities in Foster City. Dr. Lee’s new title will be Vice President, Research and Pharmaceutical Development. Dr. Lee is a co-inventor of Roche’s Cellcept® and has 15 years of research and product development experience in the pharmaceutical industry.

“With Mark and Norbert in positions of expanded responsibility, I have a great deal of confidence in our ability to take advantage of growth opportunities and build Gilead into a leading biopharmaceutical company,” said John C. Martin, President and Chief Executive Officer. “I want to join my colleagues in thanking Jeff Bird for his many significant contributions to Gilead’s success. We look forward to his continuing guidance as a consultant to Gilead and wish him well as he joins the venture capital community.”

Gilead Sciences, headquartered in Foster City, CA, is an independent biopharmaceutical company that seeks to provide accelerated solutions for patients and the people who care for them. The Company discovers, develops, manufactures and commercializes proprietary therapeutics for challenging infectious diseases (viral, fungal and bacterial infections) and cancer. Gilead maintains research, development or manufacturing facilities in Foster City, CA, Boulder, CO, San Dimas, CA, Cambridge, UK and Dublin, Ireland and sales and marketing organizations in the United States, Europe and Australia. For more information about Gilead, visit the Company's Web site at www.gilead.com.