Hepatitis C

HCV is a leading cause of chronic liver disease and liver transplants. The WHO estimates that nearly 180 million people worldwide, or approximately 3% of the world’s population, are infected with HCV. 130 million of these individuals are chronic HCV carriers who are at increased risk of developing liver cirrhosis or liver cancer, approximately 15 million of whom are in the United States, Europe and Japan. The CDC have reported that almost four million people in the United States have been infected with HCV, of whom 2.7 million were chronically infected. Approximately 2.6%, or 71,000, of these HCV patients are treated each year. Although chronic HCV infection varies greatly in its course and outcomes, 70% of chronically infected patients develop some form of chronic liver disease, including, in some cases, cirrhosis or liver cancer.

In the United States, the current standard of care for the treatment of HCV is a combination of pegylated interferon and a nucleoside analog named ribavirin. Pegylated interferon is a modified version of alpha interferon, a protein that occurs naturally in the human body and boosts the immune system’s ability to fight viral infections. Patients treated with a combination of ribavirin and interferon respond better than those treated with interferon alone. According to WHO, treatment with interferon in combination with ribavirin is effective in 30% to 50% of patients, while interferon alone is effective in approximately 10% to 20% of patients. In HCV genotypes 1a and 1b, which account for over 70% of HCV infections in the US, less than 50% of these patients respond to standard therapy consisting of pegylated interferon plus ribavirin. In addition, these therapies have serious side effects that include fatigue, bone marrow suppression, anemia and neuropsychiatric effects. As a result of the limited benefits and serious side effects of existing therapies, we believe treatment rates remain low and there are significant opportunities for new antiviral therapies to fight HCV.