The race for interferon-free HCV therapies: a snapshot by the spring of 2012.

After a decade of having been the standard of care (SOC) for the treatment of chronic HCV infection, PEGylated IFN (combined with ribavirin) is now at the verge of being complemented and then replaced by a combination of new DAAs and even some compounds interacting with host cell factors. Principal targets for the direct-acting antivirals (DAAs) are the protease NS3/4A, the protein NS5A, and the RNA-dependent RNA polymerase NS5B, which offers at least two target sites, the catalytic domain for nucleos(t)ides and several non-catalytic (allosteric) domains for the non-nucleoside type of NS5B inhibitors. Two PIs have already been approved, but many more NS3/4A, NS5A, and NS5B (up to 40!) inhibitors are in (pre)clinical development. The abundance of candidate anti-HCV drugs will, on the one hand, speed up their development but, on the other hand, complicate the choice of the most appropriate drug combination(s).