Switch to bictegravir/emtricitabine/tenofovir alafenamide from dolutegravir-based therapy: 96-week pooled analysis.

OBJECTIVE:To evaluate the efficacy and safety of 96 weeks of bictegravir/emtricitabine/tenofovir alafenamide (B/F/TAF) treatment in participants switching from dolutegravir (DTG)-based therapy. DESIGN:Studies 1489 (NCT02607930) and 1490 (NCT02607956) were phase 3 randomized, double-blind, active-controlled, first-line therapy trials in people with HIV-1. After 144 weeks of DTG-based or B/F/TAF treatment, participants could enter a 96-week open-label extension (OLE) of B/F/TAF. METHODS:A pooled analysis evaluated viral suppression (HIV-1 RNA <50 copies/mL) and changes in CD4+ cell count at OLE Weeks 48 and 96, treatment-emergent resistance, safety and tolerability after switch from a DTG-based regimen to B/F/TAF. Outcomes by prior treatment were summarized using descriptive statistics and compared by two-sided Wilcoxon rank sum test. RESULTS:At OLE Week 96, participants who switched to B/F/TAF (N=519) maintained high levels of virologic suppression (99.5% and 99.1% in those switching from DTG/abacavir/lamivudine and DTG+F/TAF, respectively) and CD4+ cell count, with no treatment-emergent resistance to B/F/TAF. Twenty-one participants experienced drug-related adverse events (AEs) after switching, with diarrhea, weight gain and headache occurring most commonly. There were no cases of proximal renal tubulopathy, drug-related Grade 4 AEs or serious AEs. Two participants discontinued B/F/TAF due to treatment-related AEs. Participants who switched from DTG/abacavir/lamivudine experienced statistically significant greater weight gain than those who switched from DTG+F/TAF; however, median weight change from the blinded phase baseline to OLE Week 96 was numerically similar across treatment groups. CONCLUSIONS:This medium-term analysis demonstrates the safety and efficacy of switching to B/F/TAF from a DTG-containing regimen in people with HIV-1.