New Hepatitis C Drugs Improve Genotype 1 Response Rates

2011 saw the release of two drugs for treating patients with hepatitis C virus (HCV) infections, both directed at improving treatment response among patients with HCV genotype 1 infections. Boceprevir (Victrelis) and telaprevir (Incivek) are protease inhibitors administered in conjunction with peginterferon and ribavirin; both new drugs were validated in manufacturer-supported randomized trials.



In the boceprevir trials, both treatment-naive patients and treatment-experienced patients in whom a previous course of peginterferon/ribavirin (PR) had failed were randomized to PR plus various boceprevir regimens or placebo. Compared with patients treated with PR plus placebo, the boceprevir groups did better across the board: Among treatment-naive patients, 67% to 68% of boceprevir recipients versus 40% of placebo recipients exhibited undetectable HCV RNA at 24 weeks after stopping treatment; among treatment-experienced patients, 59% to 66% of boceprevir recipients versus 21% of placebo recipients exhibited sustained responses



Similarly designed trials were performed with telaprevir, with similar results: Among treatment-naive patients, sustained response rates were 69% to 75% for telaprevir recipients versus 44% for placebo recipients; among treatment-experienced patients who had responded to previous PR treatment but had relapsed, rates were 83% to 88% for telaprevir recipients versus 24% for placebo recipients; and among treatment-experienced patients with previous poor responses to PR, rates were 29% to 59% for telaprevir recipients versus 5% to 15% for placebo recipients

source : New Hepatitis C Drugs Improve Genotype 1 Response Rates - Journal Watch (General)



Black patients and patients with hepatic fibrosis have particularly poor responses to standard PR treatment. Although only small numbers of these individuals were included in these trials, responses in both groups were better with the addition of the protease inhibitors. Neither set of trials included HIV/HCV-coinfected patients, for whom the drugs are not yet approved.
Side effects of the drugs were considerable, consisting of anemia at almost twice the frequency seen with PR alone, gastrointestinal problems including dysgeusia, and rash.



These two agents have been acclaimed as opening "a new era" in HCV treatment. The statistics alone certainly support this claim, but the complexity of using the drugs in clinical practice should not be underestimated. Both involve a substantial pill burden (6”“12 capsules daily) and, depending on the patient's previous and current response to treatment, a variety of schedules dictate the interweaving of the protease inhibitor treatment against the PR backbone. Finally — and this will be the deal breaker for many patients — the additional drug toxicity makes the already grueling PR regimen even harder to tolerate. Some patients might elect to power through a course anyhow, but others will prefer to await the interferon-free treatments that are still in the wings.