Gilead announced topline results from two Phase 3 studies, FISSION and NEUTRINO, evaluating a 12–week course of the once–daily nucleotide sofosbuvir in combination with ribavirin (FISSION) and in combination with ribavirin and pegylated interferon (NEUTRINO) among treatment–naïve patents with chronic hepatitis C virus (HCV) infection.

In FISSION , treatment–naive HCV genotype 2 and 3 patients were randomized (1:1) to receive either 12 weeks of sofosbuvir 400mg daily plus ribavirin (RBV) (1,000 or 1,200mg/day) (n=256) or 24 weeks of pegylated interferon (peg–IFN [180μg/week]) plus RBV (800mg/day) (n=243). In NEUTRINO, 327 treatment–naïve HCV genotype 1, 4, 5, and 6 patients were treated for 12 weeks with sofosbuvir 400mg once daily in combination with RBV (1,000 or 1,200 mg/day) and peg-IFN (180 μg/week).

The FISSION study met its primary efficacy endpoint of non–inferiority of sofosbuvir plus RBV to peg–IFN plus RBV, with 67% (170/253) of patients achieved a sustained virologic response (SVR) in the sofosbuvir plus RBV treatment group vs. 67% (162/243) in the peg-IFN plus RBV treatment group (95% CI for the difference: -7.5–+8.0% for sofosbuvir plus RBV vs. peg-IFN plus RBV; predefined criterion for non-inferiority was a lower bound of a two sided 95% CI of -15%). In the NEUTRINO study, the primary efficacy endpoint was met of superiority compared to a predefined historic control SVR rate of 60% with 90% (295/327) of patients achieving SVR12 after completing therapy (P<0.001).

For more information call (800) GILEAD-5 or visit www.gilead.com