The safety and effectiveness of ledipasvir−sofosbuvir in adolescents 12‐17 years old with hepatitis C virus genotype 1 infection

No all‐oral, direct‐acting antiviral regimens have been approved for children with chronic hepatitis C virus (HCV) infection. We conducted a phase 2, multicenter, open‐label study to evaluate the efficacy and safety of ledipasvir–sofosbuvir in adolescents with chronic HCV genotype 1 infection. One hundred patients aged 12‐17 years received a combination tablet of 90 mg ledipasvir and 400 mg sofosbuvir once daily for 12 weeks. On the tenth day following initiation of dosing, 10 patients underwent an intensive pharmacokinetic evaluation of the concentrations of sofosbuvir, ledipasvir, and the sofosbuvir metabolite GS‐331007. The primary efficacy endpoint was the percentage of patients with a sustained virologic response at 12 weeks posttreatment. Median age of patients was 15 years (range 12‐17). A majority (80%) were HCV treatment‐naive, and 84% were infected through perinatal transmission. One patient had cirrhosis, and 42 did not; in 57 patients the degree of fibrosis was unknown. Overall, 98% (98/100; 95% confidence interval 93%‐100%) of patients reached sustained virologic response at 12 weeks. No patient had virologic failure. The 2 patients who did not achieve sustained virologic response at 12 weeks were lost to follow‐up either during or after treatment. The three most commonly reported adverse events were headache (27% of patients), diarrhea (14%), and fatigue (13%). No serious adverse events were reported. Area under the concentration‐time curve (tau) and maximum concentration values for sofosbuvir, ledipasvir, and GS‐331007 were within the predefined pharmacokinetic equivalence boundaries of 50%‐200% when compared with adults from phase 2 and 3 studies of ledipasvir and sofosbuvir. Conclusion: Ledipasvir−sofosbuvir was highly effective at treating adolescents with chronic HCV genotype 1 infection; the dose of ledipasvir−sofosbuvir currently used in adults was well tolerated in adolescents and had an appropriate pharmacokinetic profile. (Hepatology 2017;66:371–378).