Vertex Reports Positive Results for Oral Hepatitis C Protease Inhibitor VX-950

Henk Reesink, associate professor of medicine at Academic Medical Center in Amsterdam, recently presented results of a Phase Ib clinical trial with the oral hepatitis C virus (HCV) protease inhibitor VX-950, an investigational drug discovered by Vertex Pharmaceuticals.

In the study, dosing with VX-950 for five and 14 days was well-tolerated in both healthy volunteers and in patients with chronic HCV infection. In addition, patients treated with 750 mg of VX-950 every eight hours achieved a median reduction of HCV-RNA of 4.4 log10, equivalent to a 25,000-fold reduction in viral levels, at the end of 14 days of treatment. At the end of 14 days of treatment, four of eight patients in the 750 mg dose group tested HCV-RNA negative in the quantitative Roche COBAS TaqMan assay; two of these four patients tested undetectable in the qualitative Roche TaqMan assay.

A patient in another VX-950 dose group also achieved plasma HCV-RNA below the limit of quantization by the end of treatment. All patients in the clinical trial had genotype 1 HCV infection, the most difficult strain to treat, and were either nonresponsive to prior treatment or treatment-naive. VX-950 is one of the most advanced of a new class of direct antivirals for hepatitis C.