Gilead Announces Data for Investigational, All-Oral, Pan-Genotypic Three-Drug Regimen of Sofosbuvir, GS-5816 and GS-9857 for Chronic Hepatitis C

-- Data Support Ongoing Trials Evaluating Shortened Course of Therapy --

VIENNA, Austria--(BUSINESS WIRE)--Apr. 23, 2015-- Gilead Sciences, Inc. (Nasdaq: GILD) today announced pre-clinical data and results from Phase 1 and Phase 2 studies supporting the development of an investigational all-oral, pan-genotypic regimen of Sovaldi^® (sofosbuvir 400 mg/SOF), the investigational NS5A inhibitor GS-5816 and GS-9857, an investigational NS3/4A protease inhibitor. These data will be presented at the 50th Annual Meeting of the European Association for the Study of the Liver (The International Liver Congress™ 2015) in Vienna, Austria.

In pre-clinical studies, GS-9857 demonstrated similarly potent antiviral activity against HCV replicons of all tested genotypes (1-6), as well as an improved resistance profile compared to other HCV protease inhibitors (ePoster #P0899). In a healthy volunteer study, GS-9857 demonstrated a favorable pharmacokinetic profile (ePoster #P0861). Data from a three-day monotherapy study also demonstrated that GS-9857 was well-tolerated and achieved median HCV RNA reductions of more than 3 log10 IU/mL for HCV patients with genotypes 1, 2, 3 and 4 at the 100 mg dose (ePoster #P0901).

Presented as a late-breaker ePoster (ePoster #LP03), a Phase 2 study of triple-combination therapy with a fixed-dose combination of SOF/GS-5816 plus GS-9857 among genotype 1 patients demonstrated sustained virologic response (SVR12) rates following six weeks of treatment of 93 percent (n=14/15) among treatment-naïve, non-cirrhotic patients, 87 percent (n=13/15) among treatment-naïve, cirrhotic patients, and 67 percent (n=20/30) among those who had failed therapy with two or more direct-acting antiviral agents (DAAs). The four-week regimen resulted in a sub-optimal SVR12 rate of 27 percent (n=4/15).

“These data support the ongoing development of GS-9857 and the potential for an all-oral, triple combination therapy containing Sovaldi, GS-5816 and GS-9857 to attempt to further reduce treatment duration for hepatitis C patients,” said Norbert Bischofberger, PhD, Executive Vice President of Research and Development and Chief Scientific Officer, Gilead Sciences. “We are encouraged by the six-week SVR12 rates and other data presented at EASL demonstrating this regimen’s pan-genotypic potential, and have recently initiated additional Phase 2 studies to further evaluate the appropriate treatment duration of this regimen for all patients, regardless of genotype, including those who have failed prior therapy with directly acting antivirals and those with cirrhosis.”

SOF/GS-5816 plus GS-9857 was generally well tolerated. There were no Grade 3 or 4 adverse events nor serious adverse events. The most frequent adverse events were nausea (25 percent), headache (24 percent) and fatigue (16 percent). Transient, asymptomatic, elevated lipase (Grade 3 or 4) occurred in four patients (5 percent).

GS-5816 and GS-9857 are investigational products and their safety and efficacy have not been established. Additional information about these studies can be found at www.clinicaltrials.gov.

About Gilead

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. Gilead has operations in more than 30 countries worldwide, with headquarters in Foster City, California.

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 Gilead may observe unfavorable results from additional clinical trials involving GS-9857, including in combination with Sovaldi and GS-5816. In addition, Gilead may make a strategic decision to discontinue development of GS-9857, including in combination with Sovaldi and GS-5816 if, for example, Gilead believes commercialization will be difficult relative to other opportunities in its pipeline. As a result, GS-9857 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 Annual Report on Form 10-K for the year ended December 31, 2014, 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 Sovaldi is available at www.gilead.com.

Sovaldi is a registered trademark of Gilead Sciences, Inc., or its related companies.

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.

Source: Gilead Sciences, Inc.

Gilead Sciences, Inc.Sung Lee, +1 650-524-7792 (Investors)Nathan Kaiser, +1 650-522-1853 (Media)Michele Rest, +1 650-577-6935 (Media)