Gilead Announces Phase 3 Results for an All-Oral, Sofosbuvir-Based Regimen for the Treatment of Hepatitis C in Patients Co-Infected With HIV

WASHINGTON--(BUSINESS WIRE)--Nov. 2, 2013-- Gilead Sciences, Inc. (Nasdaq:GILD) today announced results from a Phase 3 study, PHOTON-1, evaluating the investigational once-daily nucleotide analogue sofosbuvir for the treatment of chronic hepatitis C virus (HCV) infection among patients co-infected with HIV. In the trial, 76 percent (n=87/114) of genotype 1 HCV treatment-naïve patients receiving 24 weeks of an all-oral, interferon-free regimen of sofosbuvir plus ribavirin (RBV) achieved a sustained virologic response 12 weeks after completing therapy (SVR12). Patients who achieve SVR12 are considered cured of HCV infection. These data will be presented this week during the 64^th Annual Meeting of the American Association for the Study of Liver Diseases (The Liver Meeting 2013) in Washington, D.C.

Up to one-third of people living with HIV in the United States are co-infected with HCV. Current HCV medicines are associated with suboptimal cure rates among co-infected patients and can cause significant interactions with HIV drugs.

“There is a clear need for HCV treatment regimens that are more effective and safer for patients who are co-infected with HIV,” said Douglas Dieterich, MD, Professor of Medicine in the Division of Liver Diseases and Director of Continuing Medical Education in the Department of Medicine at Mount Sinai School of Medicine. “In this study, sofosbuvir-based all-oral therapy achieved high SVR rates in a hard-to-treat patient population. This regimen may have the potential to help us overcome the clinical challenge of treating HCV/HIV co-infection.”

PHOTON-1 also assessed 12 weeks of sofosbuvir plus RBV among genotype 2 and 3 HCV treatment-naïve patients with HIV. Among genotype 2 patients receiving this regimen, 88 percent (n=23/26) achieved SVR12, while 67 percent (n=28/42) of genotype 3 patients achieved SVR12. All patients in PHOTON-1 who did not achieve SVR12 had viral relapse after cessation of therapy, with the exception of two participants who were non-adherent to study drugs.

Treatment discontinuations due to adverse events were reported in three percent of patients receiving 24 weeks of therapy and four percent of patients receiving 12 weeks of therapy. The most common side effects observed in the study were consistent with the safety profile of RBV and included fatigue, nausea, headache and insomnia.

About PHOTON-1

PHOTON-1 is an ongoing open-label Phase 3 study being conducted at sites in the United States and Puerto Rico to evaluate the efficacy and safety of 12 or 24 weeks of sofosbuvir 400 mg once-daily plus weight-based RBV (1,000 or 1,200 mg/day) among HCV treatment-naïve patients with genotype 1, 2 or 3 HCV infection who are also HIV-positive.

Ninety-five percent of PHOTON-1 patients were receiving antiretroviral therapy for their HIV infection. The HIV treatment regimens permitted in the study were based on the results of a separate Phase 2 drug-drug interaction study conducted by Gilead demonstrating that sofosbuvir did not significantly affect the pharmacokinetic parameters of drugs from various classes of antiretrovirals. The most common HIV treatment regimens taken by patients in PHOTON-1 were Gilead’s Truvada^® (emtricitabine/tenofovir disoproxil fumarate) administered with efavirenz, atazanavir/ritonavir, darunavir/ritonavir or raltegravir.

Additional information about PHOTON-1 can be found at www.clinicaltrials.gov.

Sofosbuvir is an investigational product and its safety and efficacy have not 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 and South 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 the possibility of unfavorable longer-term resulting from clinical trials evaluating sofosbuvir, including in combination with other products and among patients with HCV/HIV co-infection or HCV monoinfection. In addition, regulatory authorities may not approve sofosbuvir for HCV-related indications and any marketing approval may have substantial limitations on its use. As a result, sofosbuvir may never be successfully commercialized. Further, Gilead may make a strategic decision to discontinue development of sofosbuvir if, for example, Gilead believes commercialization will be difficult relative to other opportunities in its pipeline. 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, 2013, 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 Truvada is available at www.gilead.com.

Truvada is a registered trademark of Gilead Sciences, Inc.

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.Patrick O’Brien, 650-522-1936 (Investors)Cara Miller, 650-522-1616 (Media)