The conquest of hepatitis C: telaprevir and beyond

Taking one pill a day for 8–12 weeks cures 98%–99% of the cases of chronic hepatitis C infections. This is one of the compelling success stories of biomedical research and drug discovery. The discovery of the hepatitis C virus (HCV) as the infective agent opened the doors to unraveling its life cycle and the identification of multiple molecular targets for drug discovery. One such target is HCV protease, an enzyme, among others, essential for virus replication. Several pharmaceutical companies, including Vertex, launched projects to find inhibitors of this enzyme. The Vertex effort overcame multiple problems and created an inhibitor known as telaprevir and marketed as Incivek. Incivek was a remarkable market entry with sales of a billion dollars in its first year. However, the success story was short-lived as Gilead Sciences came up with remarkable combination drugs for Hepatitis C. including Harvoni. Being first with a much improved product is not a guarantee of long-term success.