March 14, 2013
Hepatitis C (HCV) treatment research continues like a freight train -- one loaded with the promise of a cure for the estimated tens of millions of infected (and millions of HIV/HCV-coinfected) people around the world.
Current treatments are reminiscent of the early treatments for HIV: prone to treatment-limiting side effects, three-times daily dosing, puzzling pharmacokinetic interactions, and effectiveness that could still be improved. There's still a paucity of data on the treatment of HIV/HCV-coinfected people or the possible drug-drug interactions between the two spheres of medication. Of course, there's also the issue of the myriad difficulties of interferon-based treatments.
The French ANRS group presented two studies showing the effectiveness of the currently approved, direct-acting agents (DAAs) telaprevir and boceprevir (both taken with interferon and ribavirin [RBV]) in the treatment of HIV/HCV-coinfected people. In the ANRS HC26 study, 69 individuals on ART with HCV genotype 1 infection and previous Peg-IFN/RBV treatment failure received telaprevir. Early virologic response was reported in a remarkable 88% of individuals by week 16. This response did not appear to be impacted by liver fibrosis stage, cause of previous IFN non-response, or associated antiretrovirals.
In the ANRS HC27 study, 64 individuals on stable ART with previous virologic failure of Peg-IFN/RBV received boceprevir-based treatment with RBV. Overall, early virologic response was reported in 63% of individuals. Remarkably, 90% of patients with previous HCV treatment relapse, 56% of patients on two NRTIs with boosted atazanavir (Reyataz) and 70% of patients on two NRTIs and RAL had an "early" HCV viral response (defined as having HCV RNA below threshold value at week 16). However, only 38% of those prior null responders had virologic response with boceprevir, in sharp contrast to the 86% seen with telaprevir.
In other news, the ELECTRON study results suggest the possibility of a highly effective, interferon-free treatment for HCV. In this study of the nucleotide analog sofosbuvir (previously known as GS-7977), NS5A inhibitor ledipasvir and RBV in treatment-naive individuals (n=25) and previous null responders (n=10) with genotype 1, 100% achieved sustained virologic response.
This study also suggests that, with newer, potent, direct-acting HCV agents, predictors of poor response to treatment (such as degree of fibrosis, cirrhosis, use of full-dose interferon, IL28 status, HCV genotype or previous interferon treatment failure) may play less of a role in the future, offering the possibility of successful treatment of HCV without interferon for many who might have been thought to have a poor prognosis.
Which other studies presented at CROI 2013 will have lasting impact long after memories of the conference itself have faded? Read more of Dr. Llibre and Dr. Young's top picks.