Switching to Fixed-Dose Bictegravir, Emtricitabine, and Tenofovir Alafenamide (B/F/TAF) in Virologically Suppressed HIV-1 Infected Women: A Randomized, Open-Label, Multicenter, Active-Controlled, Phase 3, Noninferiority Trial.

Background: Bictegravir, coformulated with emtricitabine/tenofovir alafenamide as a fixed-dose combination (B/F/TAF), is recommended for treatment of HIV-1-infection. Multiple studies of B/F/TAF in treatment-naive and virologically suppressed cohorts have shown high efficacy and tolerability with no treatment-emergent resistance through 48 weeks. Participants in these studies have been predominantly men. We report 48-week results from a phase 3 study evaluating switching to B/F/TAF, specifically in a globally distributed trial population of women.

Methods: In this multicenter, randomized, open-label, active-controlled, noninferiority trial (ClinicalTrials.gov NCT02652624), women living with HIV who were virologically suppressed (HIV-1 RNA levels <50 copies/mL) on a regimen containing either TAF or tenofovir disoproxil fumarate were randomly assigned (1:1) to switch to B/F/TAF (50/200/25 mg) or stay on baseline regimen (SBR) once daily for 48 weeks. Primary endpoint was proportion of participants with plasma HIV-1 RNA ≥50 copies/mL at week 48 (U.S. Food and Drug Administration snapshot algorithm); prespecified noninferiority margin was 4%.

Findings: We randomized 472 participants and treated 470 (234 B/F/TAF, 236 SBR). Switching to B/F/TAF was noninferior to SBR for the primary outcome, as 1.7% (4/234) vs 1.7% (4/236) had HIV-1 RNA ≥50 copies/mL at week 48 (difference 0.0%, 95.001% confidence interval: -2.9% to 2.9%). No individual receiving B/F/TAF developed treatment-emergent resistance. Both treatments were well-tolerated; no participant discontinued treatment because of an adverse event.

Interpretation: Fixed-dose combination B/F/TAF provides a safe and efficacious option for ongoing treatment of HIV in women. This study contributes important data on safety, tolerability, and outcomes of antiretroviral therapy among women living with HIV.