What is Hepatitis C?
Hepatitis C or ‘Hep C’ is caused by the hepatitis C virus (HCV) and affects the liver. It is transmitted through the blood and is associated with intravenous drug use as the main vector of spread. The virus infects 2.5% of the world population with 170 million people infected. Of those infected 25% will develop liver cirrhosis or cancer within 10-20 years. In the UK since 1996, the death rate from hepatitis C has trebled with more than 200,000 people infected with hepatitis C in the UK.
What has been done?
There is an increased demand for liver transplants, so pharmaceutical companies are spending hundreds of millions of dollars on medical research to develop a new generation of drugs – ‘direct-acting antivirals’
1. In the early 1990s ‘interferon’ was used – it occurs naturally in the body, and when it is injected into the body, it stimulates the immune system and helps fight off Hepatitis C. However it also has negative side effects.
2. In 1998 ribavirin was added to the interferon, however for a year long course of this drug only 60% of patients had successful outcomes.
3. In early 2011 PSI-7977 was tested with interferon and ribavarin, with no immediate success.
4. In late 2011 PSI-7977 and ribavarin were tested with no interferon. After 3 months of treatment all 10 patients in the trial were cleared of the Hepatitis C virus.
So what next?
Phase 3 trials in the US and the UK are underway – Sofosbuvir is expected to become available in the next two years to treat patients.
Why has it been so difficult to find a cure?
– Hepatitis C mutates frequently and not consistently
– It has 6 genotypes and more than 50 subtypes.
– It has been very difficult to cultivate in the lab.
– Work was held back because it can be asymptomatic for decades.
– A quarter of people infected managed to fight it off within 6 months
– There is alot of stigma attached to the disease – thought of as a disease of the poor and of drug users