Drugs in development for viral hepatitis: care and caution.
Drugs, 2011, 71(3): 263-271.
The approval of the first direct-acting antiviral drugs for treatment of HCV is anticipated in 2011. These compounds, telaprevir and boceprevir, may improve sustained viral response rates up to 75% in treatment-naïve or relapse genotype 1 patients and will likely be used widely in the US and EU. There is the potential for misuse of these new drugs for multiple reasons such as poor understanding of treatment populations, inadequate viral assay testing, poor adverse effect management and lack of monitoring for antiviral resistance.
This article looks at the clinical skills required when administering these drugs and how genetic tests will be used. Clinical data on telaprevir and boceprevir are summarised and there is a useful table detailing the 36 small molecules for the treatment of HCV presented at the American Association for The Study of Liver Diseases meeting in 2010. Resistance, combination therapy and special populations are also discussed.
The article identifies the following key points as differences with HCV therapy in 2011 compared with previous years:
1. Pretreatment predictors will now include genotype subtyping for G1 and IL28B polymorphism testing.
2. Frequent testing of viral loads during the first 12 weeks of therapy will be needed.
3. Early discontinuation for a 1 log increase in viral load on therapy will be needed.
4. Frequent physical examinations and laboratory testing for rash, anaemia and other dose-limiting adverse events will be needed.
5. Telaprevir dosing intervals may change to every 12 hours by off-label use.
6. Practice requirements will increase with frequent patient visits, rapid lab test turnover and easy patient access to providers (electronic or otherwise).