Experimental Drug Cuts Hepatitis C Viral Load
Earlier treatment failed in 27 of 34 patients
MONDAY, Oct. 30 (HealthDay News) -- The experimental drug VX-950 can provoke a swift drop in viral RNA in patients with chronic hepatitis C, including many for whom earlier treatment had failed, according to the results of a phase 1b trial reported in the October issue of Gastroenterology.
Hendrik W. Reesink, M.D., of the Academic Medical Center in Amsterdam, the Netherlands, and colleagues randomized 34 patients with genotype 1 chronic hepatitis C to placebo or treatment with VX-950, which is a peptide that inhibits the NS3-4A protease. Patients were treated with 450 or 750 milligrams of VX-950 every eight hours or 1,250 mg every 12 hours for two weeks. Prior treatment had failed in 79 percent of patients.
The researchers found that viral loads fell 2 log10 or more in the 28 patients on VX-950; and 3 log10 or more in 93 percent of patients. Trough plasma drug concentrations were highest in the 750-mg group, which had a median hepatitis C virus RNA drop of 4.4 log10 in two weeks. The strongest effect in patients on 450-mg and 1,250-mg doses occurred from days three to seven.
"VX-950 was well tolerated and demonstrated substantial antiviral activity," the authors write. "Some patients had viral breakthrough during dosing, related to selection of variants with decreased sensitivity to VX-950. The results support further studies of VX-950 in patients with chronic hepatitis C."
The study was supported by Vertex Pharmaceuticals, Inc.