Gilead Sciences said a late-stage trial of its experimental hepatitis C treatment showed that the virus was not detected in 78 percent of patients taking the drug, 12 weeks after completing therapy.
The trial, named Positron, was testing the drug, sofosbuvir, in patients who were unable or unwilling to take interferon -- a standard hepatitis C drug known for its unpleasant side effects.
No patient in the placebo group achieved an undetectable virus level 12 weeks after completing the therapy, Gilead said.
The safety profile of the drug was similar to that observed in prior studies, and there were few treatment discontinuations due to adverse events, Gilead said.
The company said it would submit the full data from the study for presentation at a scientific conference and will share data from additional late-stage studies in early 2013.
Gilead expects to submit its first regulatory filings for sofosbuvir by mid-2013, Chief Scientific Officer Norbert Bischofberger said.
(Reporting by Esha Dey in Bangalore; Editing by Maju Samuel)