the drug’s manufacturer has announced.
The approval in the pediatric patient population was supported by 24-week data from a phase 2 clinical trial comparing treatment with tenofovir alafenamide (25 mg once daily) with placebo in 70 treatment-naive and treatment-experienced patients aged 12-18 years weighing at least 35 kg.
The study met its primary endpoint of percentage of patients with HBV DNA levels less than 20 IU/mL at 24 weeks of therapy, Gilead Sciences said in a press release.
Overall, 10 of 47 (21%) patients treated with tenofovir alafenamide achieved HBV DNA less than 20 IU/mL at 24 weeks, compared with 0 of 23 (0%) treated with placebo.
The rates of serum ALT normalization were higher with tenofovir alafenamide than with placebo (44% vs 0%).
The mean percent changes in bone mineral density (BMD) from baseline to 24 weeks were numerically similar for tenofovir alafenamide– and placebo-treated patients (2.4% and 1.9% for lumbar spine, and 1.5% and 1.9% for whole body, respectively).
The mean changes from baseline BMD z scores were –0.03 and –0.09 for lumbar spine, and –0.05 and –0.01 for whole body, for tenofovir alafenamide and placebo groups, respectively.
The FDA initially approved the nucleoside analog reverse transcriptase inhibitor in 2016 for adults with chronic HBV.
The drug was approved in Europe in 2017 for chronic HBV infection in adults and adolescents aged 12 years and older weighing at least 35 kg.
Tenofovir alafenamide carries a boxed warning citing risks for lactic acidosis/severe hepatomegaly with steatosis and posttreatment severe acute exacerbation of HBV.
A version of this article first appeared on Medscape.com.