Gilead Sciences, Inc. (Nasdaq:GILD) today announced that aztreonam for inhalation solution, an investigational product for the treatment of infections due to Pseudomonas aeruginosa (P. aeruginosa) in patients with cystic fibrosis (CF), is scheduled to be reviewed by the Anti-Infective Drugs Advisory Committee of the U.S. Food and Drug Administration (FDA) on December 10, 2009.

In September 2009, the product was granted conditional marketing approval in Canada and Europe under the trade name Cayston^® (aztreonam lysine 75 mg powder and solvent for nebuliser solution). Applications for marketing approval of Cayston are also pending in Australia, Switzerland and Turkey.

About Aztreonam for Inhalation Solution

Aztreonam for inhalation solution is an antibiotic candidate for people with cystic fibrosis who have P. aeruginosa. Aztreonam has potent in vitro activity against Gram-negative bacteria such as P. aeruginosa. Aztreonam formulated with arginine is an FDA-approved agent for intravenous administration for treating various infections. Aztreonam formulated with lysine is a proprietary formulation of aztreonam developed specifically for inhalation. It has been designated with orphan drug status in the United States and Europe.

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.

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 risks related to the Anti-Infective Drugs Advisory Committee’s review of aztreonam for inhalation solution. For example, the committee may determine that existing data from our ongoing clinical trials may not support the approval of aztreonam for inhalation solution in the United States, which may cause us considerable expense and may lead to further delays or cause us to abandon further development of the product in the United States. Further, Gilead may not obtain marketing approval of aztreonam lysine in Australia, Switzerland and Turkey, where applications are also pending. 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 Quarterly Report on Form 10-Q for the first and second quarters of 2009, 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.

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