Clinical Outcomes of Switching to Bictegravir/Emtricitabine/Tenofovir Alafenamide in People Living With HIV and Low-Level Viraemia.

IntroductionLow-level viraemia (LLV) in people living with HIV (PLWH) remains a clinical challenge, associated with increased risk of virological failure, immune dysregulation, and chronic inflammation. Bictegravir/emtricitabine/tenofovir alafenamide is a single-tablet regimen with a high genetic barrier to resistance, but real-world outcomes after switching in PLWH with LLV remain insufficiently characterized. This study aimed to describe virological, immunological, metabolic, and safety outcomes after switching to bictegravir/emtricitabine/tenofovir alafenamide in PLWH with documented LLV over 96 weeks.MethodsA retrospective, multicentre study was conducted across 12 Spanish healthcare centres. PLWH aged ≥18 years with a documented qualifying LLV episode before switch (two consecutive HIV-1 RNA measurements between 50 and 400 copies/mL) who switched to bictegravir/emtricitabine/tenofovir alafenamide were included (N = 123). Outcomes included virological suppression (<50 copies/mL), residual LLV, CD4+/CD8+ dynamics, metabolic changes, and safety. Analyses were descriptive, used observed denominators, and included a non-completer=failure sensitivity analysis for virological suppression.ResultsAmong participants (median age: 52 years, 80.5% male; median time since HIV diagnosis: 30 years), observed LLV decreased to 11.4% (13/114 patients) at 96 weeks after switching to bictegravir/emtricitabine/tenofovir alafenamide (p<0.001). In the non-completer=failure sensitivity analysis, virological suppression at week 96 was 82.1% (101/123). At week 96, all detectable HIV-1 RNA values were 55-272 copies/mL; 3/13 patients had LLV at all available 24-, 48-, and 96-week visits. CD4+/CD8+ ratios remained stable, with a significant reduction in CD8+ T cell counts in patients ≥50 years. Biochemical markers were broadly stable, but weight/BMI increases and a shift toward overweight were observed and warrant monitoring. No treatment discontinuations due to adverse events were reported.ConclusionIn this single-arm retrospective cohort, switching to bictegravir/emtricitabine/tenofovir alafenamide was associated with a high observed proportion of virological suppression, immune stability, and favourable tolerability over 96 weeks; however, causal effectiveness cannot be inferred. These findings support further comparative prospective evaluation of bictegravir/emtricitabine/tenofovir alafenamide for LLV management.