Directly acting antiviral (DAA) agents are currently revolutionizing the treatment of chronic hepatitis C infection. The first generation of these agents have significant limitations including cost issues that are of particular concern in the developing world and a lack of efficacy in genotype 3 patients. Both of these concerns are of particular relevance in Pakistan.

One cannot attend any major international liver conference over the past 1 year and not be struck by the vast array of new directly acting antiviral (DAA) agents currently in the pipeline. Telaprevir and boceprevir have already been licensed for use in Western countries. Although these and other agents will revolutionize the treatment of chronic hepatitis C, these advances threaten to leave some parts of the world, the developing world in particular, and a large proportion of the world's hepatitis C burden, behind.

AMSTERDAM, the Netherlands — A regimen of 3 direct-acting antiviral drugs plus ritonavir and ribavirin produced sustained virologic response rates in more than 90% of a broad range of patients infected with hepatitis C 24 weeks after therapy, results from a new clinical trial show.

Kris Kowdley, MD, from the Liver Center of Excellence in the Digestive Disease Institute at Virginia Mason Medical Center in Seattle, Washington, presented the results here at the International Liver Congress 2013.

The randomized, open-label, multicenter phase 2b trial, known as Aviator, shows that the sustained virologic responses seen at 12 weeks with an all-oral interferon-free regimen, presented last year at the annual meeting of the American Association for the Study of the Liver Diseases by Dr. Kowdley, are sustainable.

In the Aviator trial, noncirrhotic patients with genotype 1 hepatitis C virus who were treatment-naïve or had not responded to peginterferon and ribavirin were treated with combinations of direct-acting antiviral drugs with or without ribavirin for 8, 12, or 24 weeks.

The direct-acting antiviral drugs were once-daily ABT-450r (an NS3/4A protease inhibitor boosted with ritonavir), once-daily ABT-267 (an NS5A inhibitor), and twice-daily ABT-333 (a non-nucleoside NS5B inhibitor).

The 571 patients were predominantly white, and the mean age was 48 to 53 years. The majority, 59% to 71%, had hepatitis C genotype 1a, and mean baseline viral load was 6.6 log₁₀ hepatitis C RNA. Overall, 27% to 34% of treatment-naive patients had genotype IL28B CC, whereas only 2% to 4% of the null responders did.

Patients coinfected with HIV or hepatitis B were excluded from the study.

For the 79 treatment-naive patients who received the regimen consisting of 3 direct-acting antiviral drugs plus ribavirin for 12 weeks, 96% achieved sustained virologic response rates at 24 weeks (99% achieved this at 12 weeks).