MELBOURNE – A regimen of ABT-450 coformulated with ritonavir, ombitasvir, and dasabuvir, plus ribavirin, resulted in high rates of sustained virologic response in hepatitis C patients co-infected with HIV. Further, the treatment approach did not have a negative effect on HIV viral load.
Data from the open-label study, presented at the 20th International AIDS Conference, showed that nearly 94% of patients treated with the three-dose (3D) interferon-free regimen plus ribavirin for 12 weeks had a sustained virologic response at 4 weeks after treatment cessation. Nearly 97% of those treated for 24 weeks achieved a sustained virologic response at 4 weeks after treatment cessation.
Biance Nogrady/Frontline Medical News
Dr. Mark S. Sulkowski
The TURQUOISE-I study assessed the 3D plus ribavirin regimen in 63 patients with hepatitis C genotype 1 infection plus HIV-1 infection. The treatment group included treatment-naive patients and patients previously treated with interferon.
Dr. Mark S. Sulkowski, who presented the data, said earlier phase III studies of the 3D regimen, both with and without ribavirin, showed greater than 96% sustained virologic response rates in HCV-1–infected patients treated for 12 weeks, and 92%-96% response rates in patients with cirrhosis treated for 12-24 weeks.
"Drug interactions with hepatitis C and HIV regimens are the foremost question when approaching treatment in this group," Dr. Sulkowski, professor of medicine at Johns Hopkins University, Baltimore, told conference attendees.
Virologic failure occurred in two patients. Both had previously not responded to treatment and had compensated cirrhosis, and both also had resistance-associated HCV variants that had not been present at baseline.
The majority of adverse events were mild. The most common was fatigue, affecting 58% of patients in the 12-week arm and 37% in the 24-week arm. Other adverse events included insomnia, nausea, and headache. No patients discontinued therapy because of adverse events.
Researchers also observed grade 3 elevations in total bilirubin levels in more than 35% of patients in the 12-week arm of the study and nearly 19% of patients in the 24-week arm. Most of the grade 3 elevations occurred in patients receiving the antiretroviral atazanavir for their HIV infections.
Dr. Sulkowski said side effects and drug interactions associated with interferon therapy have largely accounted for problems in treating patients co-infected with HIV and hepatitis C.
The emerging data suggest the interferon-free regimen "works just as well in HIV-positive patients as in HIV-negative patients, so the barriers really come down to potential interactions with antiretroviral drugs," Dr. Sulkowski said in an interview.
"We now believe that HIV in and of itself is not a factor in predicting success with interferon-free regimens," he said.
Dr. Sulkowski said the Food and Drug Administration is considering applications for the 3D regimen, with and without ribavirin, with a decision expected in the fall.
Dr. Sulkowski declared grant support, consultancies, and advisory board positions with several companies, including study sponsor AbbVie.