Bictegravir/FTC/TAF Single-Tablet Regimen Well-Tolerated in Children and Adolescents

The US Food and Drug Administration (FDA) approved a single-tablet bictegravir, emtricitabine, and tenofovir alafenamide (B/F/TAF) regimen for use in adults with HIV-1 infections in February 2018. Now, investigators are exploring the safety and efficacy of the same therapy in children and adolescents aged 6 to 18 years.

B/F/TAF contains the novel integrase strand transfer inhibitor (INSTI) bictegravir (B) 50 mg, along with emtricitabine (FTC) 200 mg and tenofovir alafenamide (TAF) 25 mg.

New 48-week acceptability and palatability data from a single-arm, open-label trial, along with previously reported pharmacokinetic findings, support the use of the first, unboosted, INSTI-based single-tablet regimen of B/F/TAF 50/200/25 mg for the treatment of children and adolescents 6 to <18 years of age and weighing ≥25 kg living with HIV-1.

Investigators presented their findings in an oral abstract session at the Annual Conference on Retroviruses and Opportunistic Infections (CROI 2019) on March 5, 2019.

Fifty adolescents and 50 children were enrolled in the study and split into 2 cohorts: Cohort 1 comprising virologically suppressed adolescents (12 to <18 yrs) weighing ≥35 kg and Cohort 2 comprising virologically suppressed children (6 to <12 yrs) weighing ≥25 kg. Medians at baseline for Cohort 1 were 15 years (range 12-17 years), weight 44.7 kg (range 35-123 kg), 64% female, 65% Black, median CD4 count 751 cells/μL, and 90% vertically infected. For Cohort 2, the medians at baseline were 10 years (range 6-11 years), median weight 29 kg (range 25-69 kg), 54% female, 72% Black, median CD4 count 930 cells/μL, and 96% vertically infected.

Both cohorts received B/F/TAF once daily, and adverse events, laboratory results, and HIV-1 RNA <50 c/mL were assessed.

Investigators report that all 100 participants had HIV-1 RNA <50 c/mL at week 24 and 98% (74/75) at week 48 by FDA Snapshot Algorithm. There was no treatment-emergent resistance reported, and CD4 count remained stable to week 48.

Abdominal discomfort was the only study drug-related adverse event reported in more than a single participant (2%, 2 participants; grade 1) with a 50-week (range 20-93 weeks) median duration of exposure. One other participant discontinued at week 16 because of an adverse event of grade 2 insomnia and anxiety.

The investigators concluded that future studies are needed in the pediatric populations to explore appropriate formulations of B/F/TAF for children weighing <25 kg.

The study, “Bictegravir/FTC/TAF Single-Tablet Regimen in Adolescents and Children: Week 48 Results,” was presented on Tuesday, March 5, 2019, at CROI 2019 in Seattle, Washington.