Gilead announces update on Phase 3 study of oral fixed-dose combination of sofosbuvir and ledipasvir for genotype 1 hepatitis C patients

Gilead Sciences, Inc. (Nasdaq: GILD) today provided an update on ION-1, a Phase 3 clinical trial evaluating a once-daily fixed-dose combination of the nucleotide sofosbuvir and the NS5A inhibitor ledipasvir with and without ribavirin (RBV) for 12 or 24 weeks among treatment-naïve genotype 1 patients with hepatitis C virus (HCV) infection (n=800). A planned review by the study’s Data and Safety Monitoring Board (DSMB) of safety data from 200 patients in all four arms and of SVR4 rates (sustained virologic response four weeks after completion of therapy) from 100 patients in the two 12-week duration arms concluded that the trial should continue without modification. This recommendation is based upon the observed SVR4 rates exceeding the predefined threshold of 60 percent and the absence of significant safety issues. Enrollment of the remaining 600 patients in ION-1 is now underway.

Sofosbuvir/ledipasvir is also being evaluated in a second Phase 3 study, ION-2, initiated in January 2013, which is now fully enrolled. ION-2 is evaluating sofosbuvir/ledipasvir with RBV for 12 weeks, and with and without RBV for 24 weeks, among 400 treatment-experienced genotype 1 HCV patients. Participants in this study failed to respond to past therapy containing pegylated interferon (peg-IFN) or peg-IFN plus a protease inhibitor.

Sofosbuvir, ledipasvir and the sofosbuvir/ledipasvir fixed-dose combination are investigational products and their safety and efficacy have not yet been established.