Synergy of a hepatitis C virus (HCV) NS4A antagonist in combination with HCV protease and polymerase inhibitors.

Rapid emergence of resistance to monotherapy with virus-specific inhibitors necessitates combination therapy. ACH-806 is a hepatitis C virus NS4A inhibitor with a novel mechanism of action and resistance pathway. This compound was synergistic with NS3 protease inhibitors and NS5B nucleoside and nonnucleoside polymerase inhibitors.