The single-tablet regimen of the hepatitis C virus (HCV) NS5A inhibitor 
ledipasvir and the HCV NS5B polymerase inhibitor sofosbuvir 
(ledipasvir/sofosbuvir; Harvoni(®)) was recently approved in the US and the EU. 
The phase III ION trials included treatment-naive (ION-1 and -3) or 
treatment-experienced (ION-2) patients with chronic HCV genotype 1 infection 
(≈20 % of patients in ION-1 and -2 had cirrhosis, whereas no patient in ION-3 
had cirrhosis). A sustained virological response 12 weeks' post-treatment 
(SVR12) was seen in 99 % of treatment-naive patients receiving 
ledipasvir/sofosbuvir for 12 weeks in ION-1, with no additional benefit 
conferred by the addition of ribavirin or extending the treatment duration to 24 
weeks. Moreover, in ION-3, an 8-week regimen achieved an SVR12 rate of 94 % 
overall and 97 % in the subgroup of patients with a baseline HCV RNA level of <6 
million IU/mL. SVR12 rates of 94 and 99 % were seen in treatment-experienced 
patients who received ledipasvir/sofosbuvir for 12 and 24 weeks in ION-2. Data 
also support the use of ledipasvir/sofosbuvir in chronic HCV genotype 4 
infection, in HCV and HIV co-infection and, in combination with ribavirin, in 
patients with chronic HCV genotype 1 or 4 infection who have decompensated 
cirrhosis or are liver transplant recipients and in chronic HCV genotype 3 
infection. Oral ledipasvir/sofosbuvir was generally well tolerated. In 
conclusion, ledipasvir/sofosbuvir is an important new single-tablet regimen that 
represents a significant advance in the treatment of chronic hepatitis C.