Discontinued drugs in 2012 - 2013: Hepatitis C virus infection

Hepatitis C virus (HCV) chronically infects about 150 million people worldwide. Antiviral treatment can stop and even reverse the progression of the disease. Several antivirals have been developed. However, about 10,000 compounds are tested for each drug that eventually reaches the market. It would be useful to learn from these failures, for example, by reporting the candidate drugs that were discontinued and the reason for discontinuation. Areas covered: This article focuses on the anti-HCV drug candidates discontinued between 1 January 2012 and 1 January 2014. Expert opinion: In detail, 17 drugs were discontinued. Of these: 10 were NS5B inhibitors, 3 were NS5A inhibitors, 2 were immunostimulants, 1 was a therapeutic and prophylactic vaccine and 1 an NS3 inhibitor. Only 3 candidates were discontinued in the preclinical phase, and 14 were discontinued during clinical development (8 in Phase II and 6 in Phase I). Most discontinuations were attributed to corporate strategic decisions. The authors believe that learning from HCV drug development failures will help pharmaceutical companies and researchers to develop better strategies for the future. It is therefore important that this information is made available.