Hepatitis C or Hep C is one of five currently identified hepatitis viruses (A, B, D and E). All cause the liver to become inflamed, which interferes with its ability to function. Hep C is generally considered to be among the most serious of these viruses. Hep C can lead to chronic liver diseases such as cirrhosis (irreversible and potentially fatal scarring of the liver), liver cancer or liver failure. In the USA Hep C ranks second only to alcoholism as a cause of liver disease and is the leading reason for liver transplants.
Early symptoms of Hep C are uncommon and are generally mild and flu-like, such as fatigue, nausea or poor appetite, muscle and joint pains and tenderness in the area of the liver. Symptoms often do not appear for up to 30 years.
Hep C is transmitted by contact with blood contaminated with the virus, usually via:
One hundred and seventy million people are chronically infected with Hep C and 3 to 4 million people are newly infected each year (see Figure X). Approximately 80% of newly infected patients progress to chronic infection, and of these patients, cirrhosis develops in about 10% to 20% of cases and liver cancer in 1% to 5% of cases after a period of 20 to 30 years. Unlike Hep A and B, there is currently no vaccine for Hep C.
Figure X. Global prevalence of Hep C
The Centre for Disease Control and Prevention in the US estimates that the costs due to Hep C disease exceed US$600 million annually and it is predicted that for the years 2010 through 2019 in the USA the direct medical expenditure for Hep C related disease will be approximately US$11 billion (American Journal of Public Health study). Combination drug therapies are expensive with 48 weeks of ribavirin and interferon a-2b costing around US$12,000. This puts them out of reach of developing countries where the disease is most prevalent.
The current treatment for chronic Hep C is antiviral drugs such as interferon, which are effective in about 10% to 20% of patients. If interferon is taken in combination with ribavirin effectiveness is improved to about 30% to 50% of patients. Liver transplantation is an option for patients with end-stage liver disease.
Due principally to the cost of combination drug therapy, government and funding agencies worldwide are concentrating on efforts towards preventing the transmission of Hep C. This suggests that there is a clear need for cheaper and more effective drug therapies. The market for such products is likely to be highly significant.
The market size estimate for Hep C is based on Hep B vaccine prices and sales. As Hep B is more prevalent than Hep C (Table X), the Hep C vaccine market is assumed to be worth less than the Hep B vaccine market. This market is assumed to mostly comprise of healthcare workers, who are reported to be at a higher risk of contracting Hep B than Hep C (Rischitelli et al., 2001).
Table X. Epidemiology of Hepatitis.
The Hep B vaccine Engerix-B (GlaxoSmithKline) had worldwide sales of US$697 million in year 2000, therefore as the Hep C market is smaller, the market size is estimated to be in the region of US$ 500 million.