Directly Acting Antivirals (DAAs) for the Treatment of Chronic Hepatitis C Virus Infection in Liver Transplant Patients: "A Flood of Opportunity''

Chronic hepatitis C virus (HCV) is the leading cause of liver transplantation (LT) in adults. However, infection of the allograft is universal and associated with reduced graft and patient survival. Although successful eradication improves posttransplant outcome, current antiviral therapies have poor efficacy and tolerability. Direct acting antiviral agents (DAAs) provide new opportunities for treatment of HCV recurrence. The addition of a first-generation NS3/4A protease inhibitor (PI) has increased the efficacy of pegylated interferon and ribavirin in patients with chronic HCV genotype 1 infection. Preliminary efficacy results from open-labeled studies of PI-based triple therapy in LT recipients are encouraging. However, the tolerability of triple therapy is reduced following LT, because of increased anemia and drug-drug interactions. The use of PI-based triple therapy in LT recipients seems best suited to larger centers, experienced with management of PI toxicity. Fortunately, other classes of DAAs targeting different steps of HCV replication are in clinical trials, including nucleotide polymerase (NUC-NS5B) inhibitors, nonnucleotide polymerase (non-NUC-NS5B) inhibitors and NS5A inhibitors. Several dual and triple DAA regimens are in clinical development. Phase II studies conducted in patients before and after LT suggest that these regimens will dramatically reduce the impact of recurrent HCV. There is a tide in the affairs of men. Which, taken at the flood, leads on to fortune (Shakespeare: J Caesar Act 4, scene 3) This article reviews direct-acting antiviral agents that improve the safety and efficacy of hepatitis C virus treatment before and after liver transplantation.