Switching to bictegravir/emtricitabine/tenofovir alafenamide (B/F/TAF) in adults aged 65 years or older: week 96 results from an international, Phase 3b, open-label trial


BACKGROUND: Studies are needed to assess the safety and efficacy of antiretroviral therapy in older individuals. This is the largest, international, Phase 3b study enrolling HIV-1-infected participants '¥65 years. We report the efficacy and safety of switching to B/F/TAF at Week(W) 96.
METHODS: Virologically suppressed (VL <50 copies/mL) participants '¥65 years receiving either E/C/F/TAF or a TDF-based regimen at baseline switched to B/F/TAF. W96 VL <50 copies/mL was measured by Snapshot (secondary endpoint) and missing=excluded (M=E) analyses.
RESULTS: 86 participants were enrolled. Median age was 69 years (IQR 67, 72); 13% were female; 99% were white; 92% were receiving E/C/F/TAF at baseline. At W96 (M=E), 100% had VL <50 copies/mL with no virologic failures at W96 by M=E analysis. Snapshot results are presented in the Table. Median CD4 counts were stable. Median changes from baseline in lipid parameters were: total fasting cholesterol (-15 mg/dL), LDL (-10 mg/dL), HDL (-1 mg/dL), triglycerides (-19 mg/dL) and total cholesterol:HDL (-0.2). Median weight change from baseline was 0.0 kg. There were 2 (2.3%) Grade 3-4 study drug-related AEs, 11 (13%) Grade 3-4 laboratory abnormalities and 3 (3.5%) AEs leading to study drug discontinuation (drug-related). There were no discontinuations for renal, bone or hepatic AEs and no study drug-related serious AEs occured. Two deaths occurred that were not attributed to study drug by the site investigator.

Table 1 Efficacy at W96 (Snapshot)# participants (%)
HIV-1 RNA <50 copies/mL
64/86 (74%)
HIV-1 RNA >50 copies/mL
No virologic data in W96 window22 (26%)
discontinued study drug with last available HIV-1 RNA <50 copies/mL
visit after W96 window with HIV-1 RNA <50 copies/mL
missed W96 with no RNA assessments after W84 due to COVID-19 restrictions but W84 HIV-1 RNA <50 copies/mL

CONCLUSIONS: Through W96, high rates of virologic suppression were maintained in older participants who switched to B/F/TAF. The COVID-19 pandemic affected in-person visits affecting W96 data; however, study teams were able to keep participants in care through telehealth. The safety and efficacy data support the switch to B/F/TAF in virologically suppressed, HIV-infected individuals aged '¥65 years.