Researchers working on finding a cure for hepatitis C virus (HCV) infection will look back on 2011 as a year of achievement.
A United States Food and Drug Administration advisory committee collectively recommended that two new hepatitis C drugs, boceprevir and telaprevir, be approved. There is now hope for people with hepatitis C, including those who are co-infected with HIV.
Merck and Co is developing boceprevir, and Vertex Pharmaceuticals is bringing out telaprevir.
Mark S. Sulkowski, MD, from Johns Hopkins University School of Medicine, Baltimore, Maryland is excited about FDA (1) on the brink of approving 2 hepatitis C protease inhibitors — boceprevir and telaprevir, in combination with peginterferon and ribavirin. He believes these two drugs will mark a new period of direct antiviral therapy that will enhance the ability to cure hepatitis C genotype 1.
Dr. Sulkowski observes that the FDA has not approved any new HCV medication since 1998 when the agency approved ribavirin in combination with standard interferon-alfa. Although peginterferon was introduced in 2001, it was only a modification of interferon.
Better cure rates
The cure rate of present hepatitis C treatment is around fifty percent. Both boceprevir and telaprevir when combined to the current standard treatment, offer positive results.
Phase 3 clinical trials indicate that boceprevir increased cure rates in both treatment-naïve and treatment-experienced HCV patients to about 66 percent. Cure rates for telaprevir were about 70 to 80 percent for treatment-naïve participants and 65 percent for treatment-experienced patients.
Although the rates for telaprevir seem greater than those for boceprevir, it is not evident whether telaprevir is actually more effective.
Patients who were given the standard treatment of just ribavirin combined with Pegasys in the telaprevir trials had a better cure rate compared to patients in the boceprevir trials who received only ribavirin combined with PegIntron. Therefore, it is likely that the differences in cure rates between the trials are, in fact, due to Pegasys Vs PegIntron, or due to other differences between the studies. A few studies have also shown that Pegasys is more effective compared to PegIntron.
Trials in which telaprevir and boceprevir are analysed directly is essential before deciding whether one drug is more effective than the other.
These two new treatments also have new serious side effects and possibly complex dosing regimens.
Lorren Sandt, Executive Director of the Caring Ambassadors Hepatitis C Program, stated that a drug taken three times a day every eight hours, with food, while you’re having diarrhoea, nausea, and vomiting is something to be concerned about.
Patients who took part in clinical trials for both drugs usually experienced fatigue and nausea. Another serious concern raised by the advisory committee was that both drugs were incidental with more regular and intense anaemia, which in some cases could lead to heart problems and involve blood transfusions.
Standard hepatitis C treatment, especially with ribavirin, is already associated with anaemia.
In the boceprevir trials, around half of the participants showed signs of anaemia, compared to 30 percent of participants who were not given the drug. In the telaprevir trials, 36 percent showed signs of anaemia and 15 percent who did not receive the drug.
Almost 55 percent of participants taking telaprevir reported getting a rash and about 20 percent showed signs of itchiness or inflammation in the rectum.
Benefits outweigh risk
Patients who were treated with these two drugs in clinical trials state that the benefits of the drugs outweigh their risks.
José M. Zuniga, PhD, MPH, president and CEO of the International Association of Physicians in AIDS Care (IAPAC) (2) acknowledges the addition of boceprevir and telaprevir to the HCV treatment regimen and believes that it will boost the clinical management of the ailment, which has left medical professionals with less prescription options and patients with tricky treatment options.
1) U.S. Food and Drug Administration (FDA)
2) International Association of Physicians in AIDS Care (IAPAC)