Novartis snapped up the leading candidate of an emerging class of hepatitis C drug when it licensed the cyclophilin inhibitor Debio-025 from Swiss compatriot, Debiopharm, even before it could report phase II trial results. A review of the R&D pipeline shows, however, that neither cyclophilin inhibitors nor Debio-025, now dubbed alisporivir, are likely to be the first new class to hit a market in which an estimated half of patients do not respond to the current standard of care.

Should they succeed, two hepatitis C protease inhibitors now in phase III trials would be more likely to hit the market first and take their places alongside pegylated interferon alpha and ribavarin treatments that are now the standard of care. It is an area of significant need; an estimated 170 million people worldwide are estimated to be infected with the hepatitis C virus, many co-infected with HIV, and current treatments can result in severe side effects and adverse reactions.