About CobicistatCobicistat 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. Gilead submitted an NDA to FDA for cobicistat as a standalone agent on June 28, 2012, and a PDUFA date of April 28, 2013 has been set. TAF-containing regimens and TAF, elvitegravir and cobicistat as single agents are investigational products and their safety and efficacy have not yet been established. 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 risks related to our ability to enroll patients in the clinical trials involving TAF and the possibility of unfavorable results from these clinical trials. In addition, Gilead may make a strategic decision to discontinue development of TAF if, for example, Gilead believes commercialization will be difficult relative to other opportunities in its pipeline. There is also risk that Gilead may not be able to commence the second clinical trial of TAF and file for regulatory approval of TAF in the anticipated timelines. Further, Gilead may be unable to obtain approvals from regulatory authorities for TAF, elvitegravir and/or cobicistat, alone or in combination with other products. If marketing approval is granted for any of these products, there may be significant limitations on their use. As a result, these product candidates as standalone agents or as part of single tablet regimens may never be successfully commercialized. 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 quarter ended September 30, 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.