Real-life data of immune recovery using bictegravir/emtricitabine/tenofovir alafenamide in virologically suppressed people living with HIV. Results at 48-96 weeks of RETROBIC Study.

Background: Switching strategy with bictegravir/emtricitabine/tenofovir alafenamide (B/F/TAF) has become a gold standard for people living with HIV (PLWH), achieving high efficacy and safety rates. However, data regarding immune status in long-term real-life cohorts of pretreated patients are needed.

Methods: We performed a multicentre, non-controlled, retrospective study in virologically suppressed PLWH switching to B/F/TAF. We evaluated CD4+, CD8+ and CD4+/CD8+ ratio, efficacy and safety at weeks 48 and 96.

Results: The study comprised 1966 PLWH from 12 hospitals in Spain, of whom 80% were men, and the median age was 51.0 [42.0-57.0] years. The median time of HIV infection was 18.0 [10.0-27.0] years. No significant changes in CD4+, CD8+ T cells, or CD4+/CD8+ were observed after 96 weeks. Nevertheless, in women at weeks 48 and 96, we found a significant increase of CD4+ T cells and a significant decrease in CD8+ T cells. In patients ≥60 years at week 96, CD4 T cells significantly increased and CD8+ T cells significantly decreased at week 48. The on-treatment analysis revealed HIV-RNA <50 copies/mL in 95.6% (1700/1779) and 96.7% (1312/1356) of patients at weeks 48 and 96, respectively. The rates increased to 99.2% (1765/1779) and 99.7% (1352/1356) when considering HIV-RNA <200 copies/mL. No resistance mutations were detected in virologic failures. B/F/TAF discontinuations accounted for 10.2% (200). Simplification was the most common reason for discontinuation in 3.8% (74) of patients.

Conclusion: In long-term virologically controlled PLWH, B/F/TAF achieved high efficacy rates and slightly improved immune status in women and individuals aged 60 and over after 48 and 96 of switching.