March 26, 2012
News from the latest major HIV research conference continues to look great for hepatitis C (HCV) cures.
More results from a Victrelis (boceprevir) treatment trial were unveiled at the 19th Conference on Retroviruses and Opportunistic Infections (CROI 2012) in Seattle, Wash. The researchers showed results of treatment 12 weeks after 95 HIV-infected patients with HCV genotype 1 infection had finished 48 weeks of treatment with either a) PEG interferon plus ribavirin plus placebo (i.e., dual therapy, which has been the standard of treatment for many years) or b) PEG interferon plus ribavirin plus Victrelis (i.e., triple therapy).
The 12-week, "off-treatment" data show how much better triple therapy is than dual therapy. The percentage of patients who still had no detectable HCV in their blood was 61 percent in the triple-therapy group compared to 27 percent in the dual-therapy group.
The side effects were the same ones seen in the Victrelis trials that involved patients with HCV alone: mainly anemia (loss of red blood cells) and a bad taste in the mouth.
These encouraging results suggest that triple therapy is going to improve the treatment outcomes in coinfected patients by a wide margin. The final, 24-week post-treatment data will be presented later in the year. Bigger trials of triple therapy in HIV/HCV-coinfected patients are planned.
However, there is also the problem of drug interactions, which makes us remember that the treatment of HCV in the HIV-infected patient is certainly not straightforward, and we need to proceed with caution.
At CROI 2012, the maker of Victrelis showed data on drug interactions with HIV medications in 39 healthy volunteers. These persons were given one HIV protease inhibitor (e.g., Kaletra [lopinavir/ritonavir], Prezista [darunavir, TMC114] or Reyataz [atazanavir]) for about three weeks. Then they took the same HIV protease inhibitor in combination with Victrelis. Unfortunately, the combinations led to low blood levels of these HIV protease inhibitors. This can affect HIV control.
In addition, Kaletra and Prezista both cut down the levels of Victrelis. This can affect HCV treatment responses.
Meanwhile, in another study, the combination of Victrelis and the integrase inhibitor Isentress (raltegravir) did not lead to any drug interactions of concern.
So at this time, if you are taking Victrelis triple therapy and you are on an HIV protease inhibitor, contact your doctor to discuss these new study results -- but do so before you stop any of your medications, since stopping medications entirely may more quickly lead to resistance.
When you talk to your doctor, you may want to ask whether you need to switch around your HIV medications. Right now, Truvada (tenofovir/FTC) plus Isentress seems to be the safest bet among the standard first-line treatment options.