There is a need for interferon-free treatment regimens for hepatitis C virus infection.
Dr Fred Poordad and colleagues from Texas, USA evaluated ABT-450, a potent hepatitis C virus NS3 protease inhibitor, combined with low-dose ritonavir, in addition to ABT-333, a nonnucleoside NS5B polymerase inhibitor, and ribavirin, for the treatment of hepatitis C virus infection.
The team of doctors conducted a 12-week, phase 2a, open-label study involving patients who had hepatitis C virus genotype 1 infection without cirrhosis.
All patients received ABT-333 and ribavirin, and one of two daily doses of ABT-450/r.
Groups 1 and 2 included previously untreated patients.
Group 1 received 250 mg of ABT-450 and 100 mg of ritonavir, and Group 2 received 150 mg and 100 mg, respectively.
|Sustained virologic response 12 weeks after the end of treatment was achieved in 95% of Group 1|
|New England Journal of Medicine|
Group 3, which included patients who had had a null or partial response to previous therapy with peginterferon and ribavirin, received daily doses of 150 mg of ABT-450 and 100 mg of ritonavir.
The team's primary end point was an undetectable level of hepatitis C virus RNA from week 4 through week 12.
A total of 17 of the 19 patients in Group 1, and 11 of the 14 in Group 2 had an extended rapid virologic response.
There was a sustained virologic response 12 weeks after the end of treatment was achieved in 95% and 93% of the patients, respectively.
The researchers observed that in Group 3, 10 of 17 patients had an extended rapid virologic response, 8 had a sustained virologic response 12 weeks after therapy, 6 patients had virologic breakthrough, and 3 had a relapse.
The team noted that adverse events included abnormalities in liver-function tests, fatigue, nausea, headache, dizziness, insomnia, pruritus, rash, and vomiting.
Dr Poordad's team concludes, "This preliminary study suggests that 12 weeks of therapy with a combination of a protease inhibitor, a nonnucleoside polymerase inhibitor, and ribavirin may be effective for treatment of HCV genotype 1 infection."