February 28, 2012
The news about hepatitis C (HCV) treatment in the HIV-positive patient with genotype 1 infection continues to be exciting. As a reader of TheBody.com you have probably already seen my blog entry on the use of Incivek (telaprevir) with pegylated interferon (PEG) and ribavirin (RBV), which has some great early "on-treatment" results.
Incivek is an HCV protease inhibitor that acts directly on HCV itself. With the use of this specifically targeted drug, the effect on a person's HCV viral load is much more dramatic than anything we have seen before with just PEG and RBV.
Now I would like to share with you some similarly encouraging early data on the use of another HCV protease inhibitor named Victrelis (boceprevir). In a small trial, 100 HIV/HCV-coinfected patients were all given the usual treatment of PEG/RBV. However, some patients were also given Victrelis, while others were given a placebo (a sugar pill) to see if the Victrelis might improve the treatment response by comparison. Victrelis (or placebo) was started after four weeks of PEG/RBV. These first four weeks are called the "lead-in" phase.
Most of the patients in this trial did not have cirrhosis, which is an advanced stage of liver disease. About 88 percent had a high HCV viral load (>800,000 IU/mL). After the "lead-in" of only PEG/RBV, the percentage of patients who had no detectable virus in their blood was unsurprisingly low in both arms of the study (8 percent versus 5 percent).
However, at week 8, the percentage of patients with no detectable virus was much higher in those who got Victrelis added on (38 percent) than those who got the addition of a placebo (15 percent). Already at week 8 we begin to see the advantage of having a drug that specifically targets HCV added on to a regimen of PEG and RBV.
This favorable trend has continued to week 24, study results show; 71 percent had viral suppression on the Victrelis arm compared to 38 percent in the placebo arm.
We know from earlier trials of HCV that the faster your virus is suppressed, the better your chance of cure. Although we don't know the final treatment outcomes from this study yet, I am very encouraged about the big difference that HCV protease inhibitors are going to make in the lives of HIV-positive patients with HCV infection.
As with any drug, there are medication side effects to talk about. Just like RBV, Victrelis can cause anemia (a drop in your red blood cells). Victrelis can also cause a bad taste in the mouth and loss of appetite. Blood tests are monitored to see if there are any problems of concern, such as drops in red or white blood cell counts.
Victrelis can only be given with one HIV regimen: Truvada plus Isentress. It is important not to take Victrelis with other HIV medications because of drug interactions that reduce drug levels in your blood, which could lead to loss of HCV or HIV control. However, if you are already taking Victrelis with other HIV medications, don't just stop your medications. It is very important to first contact your doctor for further advice.
We will know more about the safety of this drug when the full trial results are available in 2013.
So far, the Incivek and Victrelis trials are making me very hopeful that the tide is turning in the treatment of liver disease in the HIV/HCV-coinfected patient!
Victrelis: A specific HCV protease inhibitor similar to Incivek. Victrelis is also know by the generic name "boceprevir."
Cirrhosis: Patients with cirrhosis have knots of scarring that can affect the liver's ability to make certain important proteins in the body. Cirrhosis is considered an advanced form of scarring.
Lead-in phase: In trials of Victrelis, the lead-in phase refers to the early portion of the trial in which volunteers were given just pegylated interferon and ribavirin ("dual therapy") for four weeks. After this lead-in, either Victrelis or a placebo was added to the treatment regimen to see how much of a difference they made.