https://www.ncbi.nlm.nih.gov/pubmed/31220349 Hepatitis C

Hepatology. 2019 Jun 20. doi: 10.1002/hep.30830. [Epub ahead of print]
Ledipasvir-Sofosbuvir for 12 Weeks in Children 3 to <6 Years Old With Chronic Hepatitis C.

Schwarz KB1, Rosenthal P2, Murray KF3, Honegger JR4, Hardikar W5, Hague R6, Mittal N7, Massetto B8, Brainard DM8, Hsueh CH8, Shao J8, Parhy B8, Narkewicz MR9, Rao GS10, Whitworth S11, Bansal S12, Balistreri WF13.

Abstract
For children under 12 years of age who have chronic hepatitis C virus (HCV) infection, there are currently no approved treatments with direct-acting antiviral agents. We therefore evaluated the safety and efficacy of ledipasvir-sofosbuvir in HCV-infected children aged 3 to <6 years old. In an open-label study, patients 3 to <6 years old chronically infected with HCV genotype 1 (n=33) or 4 (n=1) received weight-based doses of combined ledipasvir-sofosbuvir as granules (33.75 mg/150 mg for weights <17 kg or 45 mg/200 mg for weights ≥17 kg) for 12 weeks. The primary endpoint was sustained virologic response 12 weeks after treatment (SVR12). For the first 14 patients, intensive pharmacokinetic sampling was done on day 10 of treatment. All patients had been infected through perinatal transmission and were treatment naïve. No patients had known cirrhosis. Ten patients (29%) weighed <17 kg. SVR12 was achieved in 97% of patients (33/34); the patient who did not achieve SVR12 was 3 years old and discontinued treatment after 5 days because of an adverse event 'abnormal drug taste'. The most common adverse events were vomiting (24% of patients), cough (21%), and pyrexia (21%). No patients experienced a serious adverse event. Intensive pharmacokinetic analysis of 13 patients for whom data were evaluable confirmed that the doses selected were appropriate. CONCLUSIONS: Ledipasvir-sofosbuvir was well tolerated and highly effective in children 3 to <6 years old with chronic HCV infection.