In high-income countries such as Canada, Australia and the U.S. and in regions such as Western Europe, hepatitis C virus (HCV) can be spread in the following ways:
- by sharing equipment for substance use (such as needles, straws and rolled-up currency bills)
- by having unprotected anal sex (particularly among men who have sex with men)
- by sharing sex toys
- by being exposed to unsterilized equipment used for tattooing and body piercing
In previous decades, HCV could also be spread through blood transfusions or receipt of blood products such as clotting factors. However, in high-income countries today the blood supply is very safe.
As there is no vaccine available to provide protection from HCV, prevention efforts are critical.
Treatment options expand
In the past decade, treatment for HCV infection has been a combination of these two drugs:
- a long-lasting form of interferon-alpha called pegylated interferon-alpha (peginterferon), taken once weekly
- a broad-spectrum anti-HCV drug called ribavirin, taken twice daily
Treatment with these drugs lasted for between 24 and 48 weeks, depending on what strain of HCV a person was infected with and other factors.
In high-income countries today, regulatory agencies have licensed two new drugs for HCV treatment:
- boceprevir (Victrelis)
- telaprevir (Incivik)
Each drug is meant to be taken in addition to peginterferon and ribavirin. Both boceprevir and telaprevir have to be taken three times daily (every eight hours). This triple therapy is effective at curing HCV infection in some people.
This drug is prescribed at a dose of 750 mg three times daily (every eight hours) and is generally used as part of triple therapy, along with peginterferon and ribavirin, for 12 consecutive weeks. After this time, depending on how HCV responds to therapy and a person’s treatment history, telaprevir is taken for an additional 12 or 36 weeks, also with peginterferon and ribavirin.
This drug is prescribed at a dose of 800 mg three times daily (every eight hours) in combination with peg-interferon and ribavirin. All patients first receive a four-week lead-in period with dual therapy with peginterferon and ribavirin, followed by the addition of boceprevir. Depending on how a person’s HCV responds to triple therapy, boceprevir-based therapy can last for between 28 and 48 weeks.
All drugs have side effects and those associated with these two new therapies are discussed in TreatmentUpdate 188. To summarize, the main side effects are as follows:
- peginterferon – problems with sleep, anxiety, fatigue and depression
- ribavirin – anemia, fatigue
- boceprevir – anemia, altered sense of taste
- telaprevir – skin problems (rash, itchiness), anemia
Both boceprevir and telaprevir appear to enhance ribavirin-associated anemia.
Although therapy with either boceprevir or telaprevir can be very effective, the four therapies currently licensed for HCV infection are not ideal because of their frequent dosing, side effects and, in some cases, complex drug interactions. Also, boceprevir and telaprevir are licensed for the treatment of one strain of HCV - genotype 1. There are many HCV genotypes (from 1 to 6) and subtypes within these (such as genotype 1a and 1b and so on), so new therapies are needed to treat these other strains.
In this issue of TreatmentUpdate we explore data concerning boceprevir and telaprevir as well as some of the other HCV drugs in development.