[Update on hepatitis C therapy. New drugs, treatment response monitoring and emergence of resistance].

The development of novel direct antiviral agents (DAAs) against hepatitis C virus (HCV) has represented a breakthrough in the treatment of chronic hepatitis C. Telaprevir and boceprevir are the first two protease inhibitor (PI) DAAs to be approved for combination therapy with pegylated interferon (PEG-IFN) and ribavirin (RBV). In genotype 1 monoinfected patients, triple PI therapy has increased sustained viral response (SVR) rates by approximately 30% compared with conventional combination therapy. The introduction of these drugs into clinical practice will modify the timing of monitoring parameters in diagnostic laboratories, especially with regard to stopping rules and to faster delivery of results. In the near future, new DAAs, directed against different targets of the HCV cycle (polymerase inhibitors, viral replication complex inhibitors and cyclophilin inhibitors), which are currently in various stages of clinical development, will be available. Some of these DAAs have already reached advanced phases of development, both in combination with PEG-IFN and RBV and in interferon-free therapy, with very high rates of SVR.