Gilead’s three-arm Phase IIa trial evaluated the safety and efficacy of GS 9190, an oral polymerase inhibitor, in combination with GS 9256, an oral protease inhibitor, when used as a dual antiviral therapy alone; a three-drug regimen with RBV; or a four-drug regimen with RBV and Peg-IFN.
The study found that the all-oral regimen of GS 9190, GS 9256 and RBV produced viral suppression, with a median maximal decline from baseline in HCV RNA of 5.1log10 IU/mL during 28 days of treatment.
Additionally, among patients given the four-drug regimen of GS 9190, GS 9256, RBV and Peg-IFN, 100% achieved Rapid Virologic Response (RVR) at day 28, with 93% achieving undetectable viral levels.
Principal investigator of the study Stefan Zeuzem said that the data support the continued clinical evaluation of GS 9190 and GS 9256 in combination with other hepatitis C therapies and provide additional clinical insight into the effect of Ribavirin in the absence of interferon.
Gilead Liver Disease Therapeutics senior vice president John McHutchison said that oral combinations of multiple antiviral agents are expected to become the new standard of care for patients with hepatitis C.
"These data support the clinical potential of this oral combination HCV therapy, and we’re looking forward to advancing the development of GS 9190 and GS 9256," McHutchison said.