The standard combination drug treatment of pegylated interferon and ribavirin has only had a limited amount of success. Although it is an improvement on previous treatment, approx 50% of those treated (depending on genotype) still do not clear the virus. The side effects for some people can also be debilitating and occasionally intolerable and are the cause of a number of people stopping treatment altogether. It is also expensive. There is currently an urgent need for more effective and better tolerated treatments.
This is especially the case for a growing number of people for whom treatment has not been successful and for those with a lower chance of achieving a sustained virologic response (SVR).
- Those with genotype 1 and a high viral load.
- People with advanced liver damage (compensated and decompensated cirrhosis).
- Those co-infected with HIV/HCV.
- Previously treated non-responders.
- Those who have relapsed.
- Liver transplant recipients, virtually all of whom develop recurrent HCV infection.
The high prevalence of HCV infection in the developed world means that its treatment is a potentially lucrative market for pharmaceutical companies. This has meant that a great deal of research, time and money is now being spent on new HCV therapies.
There are currently about 48 treatments in trial. Some are monotherapies (drugs or therapies taken on their own) and some are for use in conjunction with existing HCV treatments. Some of these developmental treatments have shown promising results in clinical trials.
Two drugs that have already been approved for safety by the FDA and the European equivalent are Telaprevir (Janssen) and Boceprevir (Merck/MSD).
Both of these drugs are protease inhibitors, which are treatments that aim to prevent HCV from replicating. More information on protease inhibitors can be found in the 'Drugs that target the virus' section.
Peg-interferon/Ribavirin will continue to be the main form of treatment for some time. This is because those treatments closest to being licensed will be used in combination with interferon and ribavirin. So, alongside the search for new treatments, improving the effectiveness and tolerability of interferon-based treatments is another vital area of research.
At present, research into new HCV treatments is predominantly focused on three approaches:
- Treatments that target the virus
- Treatments that boost the human immune response to HCV
- Modifications to interferon based treatments