Gilead Sciences, Inc. (Nasdaq: GILD) today announced interim data from the Phase 2 ELECTRON study examining the investigational once-daily oral agent GS-7977 plus ribavirin (RBV) in treatment-naïve patients with genotype 1 chronic hepatitis C virus (HCV) infection. Of the 25 patients who completed 12 weeks of treatment with the GS-7977-based regimen, 88 percent of patients (n=22/25) remained HCV RNA undetectable four weeks after completion of treatment. Three patients experienced viral relapse. These findings are being presented this week during a poster session (Poster #1113) at the 47 th Annual Meeting of the European Association for the Study of the Liver (International Liver Congress 2012) in Barcelona, Spain. “These preliminary results suggest that 12 weeks of therapy with once-daily oral GS-7977 and ribavirin may be enough to cure hepatitis C in many genotype 1 patients, including those who are currently not candidates to receive interferon,” said Professor Edward Gane, MD, Deputy Director and Hepatologist, New Zealand Liver Transplant Unit, Auckland City Hospital in New Zealand, and principal investigator of the ELECTRON study. “Further investigation of GS-7977 in a variety of patient populations and combinations will be important in assessing the drug’s potential as part of an all-oral regimen for hepatitis C.” Results from three additional arms of the ELECTRON study examining GS-7977-based therapy in various patient populations are also being presented this week at the International Liver Congress. These include null responder genotype 1 patients, and genotype 2 and genotype 3 patients, both treatment-naïve and prior non-responders. Overall, GS-7977 was well tolerated and exhibited a favorable safety profile. No patients experienced viral rebound during treatment. No patients discontinued therapy due to an adverse event. The most common adverse events were fatigue, dizziness and headache, and two grade 3/4 laboratory abnormalities were reported. Gilead today also announced interim results from a second Phase 2 trial (QUANTUM) examining a 12- and 24-week duration of GS-7977 plus RBV in treatment-naïve patients. Twenty-five patients were randomized to the 12-week treatment arm: 19 genotype 1 patients; four genotype 3 patients; and two genotype 2 patients. Two genotype 1 patients discontinued therapy prematurely during the 12-week treatment period. At the four-week post-treatment time period, data were available for 17 genotype 1 patients. Of these, 10/17 (59 percent) remained HCV RNA undetectable. Seven patients (41 percent) experienced viral relapse. Additionally, seven of the patients who have reached the eight week post-treatment time period, and who achieved SVR4, remain HCV RNA undetectable.