2009 Progress Likely to Change HCV Treatment to Triple Therapy
Looking back on the research and development of 2009, the scientific community witnessed unprecedented innovation in the fight against the Hepatitis C virus (HCV). Based on what has emerged this past year in the pharmaceutical industry, we can expect great strides in HCV treatments well into this new decade.
With an estimated 170 million people worldwide with chronic Hepatitis C, this virus has emerged as one of the most problematic infections of the 21st century. For nearly half of those treated for the most common strain of HCV (genotype 1), the standard antiviral drugs (a combination of interferon and ribavirin) do not succeed in clearing the virus from the liver. Those who are unable to clear HCV are at risk of their liver disease advancing to debilitating – or even fatal consequences.
Hepatitis C does not play fair – especially in which people are most likely to beat the virus. Although about half of HCV genotype 1 infections can be conquered by current treatment, a person’s genes can contribute or detract from those odds:
- Americans with Hepatitis C have between a 38 and 41 percent likelihood of responding to interferon/ribavirin treatment, depending on the level of virus in their bodies as well as the drug dosages.
- The likelihood of responding to HCV treatment is higher among European than American patients.
- Due to genetic differences, as few as 25 percent of African-Americans respond to HCV treatment.
That is why John McHutchison, a liver specialist at the Duke Clinical Research Institute in Durham, North Carolina, tells his patients with HCV that combination therapy would only give them a 40 percent chance of curing their infection. McHutchison also tells his patients that in about 18 months, new treatments could be available that would improve their chances.
The length of time people will have to wait for new HCV medication options depends on the outcomes of drugs currently in Phase III clinical trials. While interferon is a non-specific immune system booster and ribavirin is an antiviral medication, the strategy of most of the up and coming HCV drugs is to undermine the virus’ ability to replicate.
The two drugs that are furthest along in development are the HCV protease inhibitors telaprevir and boceprevir. Right now, both of these drugs are being evaluated as a triple therapy, taken alongside pegylated interferon plus ribavirin.
- Triple therapy with telaprevir – In 2009, clinical trial data demonstrated that 69 percent of genotype 1 treatment-naïve patients cleared HCV in 24 weeks with a combination of telaprevir, pegylated interferon and ribavirin.
- Triple therapy with boceprevir – In 2009, clinical trial data demonstrated that 75 percent of genotype 1 treatment-naïve patients cleared HCV in 48 weeks with a combination of boceprevir, pegylated interferon and ribavirin.
Telaprevir and boceprevir will finish their development cycle in 2010, and the Phase III data is expected to be sent to the Food and Drug Administration (FDA) for marketing approval in 2010-2011. If there are no glitches in the data, safety concerns or other roadblocks, the FDA could approve these drugs by 2011.
As we plunge into the next decade of Hepatitis C research and development, we are likely to see more effective drug combinations come to fruition. Even if something slows down the boceprevir or telaprevir Phase III clinical trials, a triple therapy for Hepatitis C is coming – and it promises to increase the chances of beating this virus for people from all backgrounds.
http://www.hcvadvocate.org/hepatitis/hepC/HCVDrugs.html, Hepatitis C Treatments in Current Clinical Development, Alan Franciscus, Retrieved December 31, 2009, Hepatitis C Support Project, 2009.
http://www.hcvadvocate.org/news/newsLetter/2010/advocate0110.html, HCV Pipeline, Alan Franciscus, Retrieved December 31, 2009,. Hepatitis C Support Project, 2009.
http://www.ncbi.nlm.nih.gov/pubmed/19684573, Genetic variation in IL28B predicts hepatitis C treatment-induced viral clearance, GE D, et al, Retrieved January 1, 2010, Nature, September 2009.
http://www.scientificamerican.com/article.cfm?id=hepatitis-virus-hcv-drug-treatment-vaccine&print=true, Triple-Drug Cocktail in the Works for Hepatitis C Therapy, Carina Storrs, Retrieved December 31, 2009, Scientific American, December 2009.