Effectiveness of Bictegravir/Emtricitabine/Tenofovir Alafenamide in Virologically Suppressed People with HIV on Any Antiretroviral Therapy Regimen: The Retrospective ESSENTIAL Study

Real-world evidence on the effectiveness and durability of bictegravir/emtricitabine/tenofovir alafenamide (BIC/FTC/TAF) as a switch strategy in virologically suppressed people with HIV (PWH) is important for clinical decision-making, particularly in ageing populations with multiple comorbidities and concomitant medications and in individuals previously treated with rilpivirine. ESSENTIAL (GS-IT-380–7059) is a retrospective, single-centre observational study including adults with HIV-RNA < 50 copies/ml who switched to BIC/FTC/TAF between July 2019 and April 2024 at ASST Fatebenefratelli Sacco, Milan, Italy. The primary endpoint was the virological suppression rate (HIV-RNA < 50 copies/ml) evaluated at 6 and 12 months after switching to BIC/FTC/TAF (observed-case analysis of available data). Secondary endpoints included treatment durability (Kaplan-Meier estimates of time to treatment interruption for any cause) and safety. A prespecified subgroup analysis evaluated individuals switching from rilpivirine/emtricitabine/tenofovir alafenamide (RPV/FTC/TAF). Overall, 799 individuals were included (median age 53 [IQR 45, 58] years; 83% male). The cohort reflected substantial clinical complexity: 82.6% had ≥ 1 comorbidity (predominantly metabolic) and 34.2% were taking ≥ 3 concomitant medications; potential drug-drug interactions with the pre-switch antiretroviral regimen were identified in approximately 14% of cases. After the switch, virological suppression was maintained in 97.4% of participants at 6 months and 98% at 12 months. In the subgroup switching from RPV/FTC/TAF (n = 103), virological suppression rates were 93.9% at 6 months and 98% at 12 months, with only two confirmed virological failures. Kaplan-Meier analysis showed high treatment durability with few discontinuations, most of which were unrelated to virological failure or adverse events. Adverse events were infrequent (0.8% at 6 months; 0.3% at 12 months), with no unexpected safety signals during follow-up. In this large real-world cohort of virologically suppressed individuals, characterized by ageing, high comorbidity burden, and frequent concomitant medication use, switching to BIC/FTC/TAF was associated with sustained virological control and good tolerability over 12 months, including among those transitioning from RPV-based regimens. These findings provide additional real-world evidence supporting BIC/FTC/TAF as a durable and well-tolerated switch strategy in routine clinical practice. People living with HIV may need to change treatment over time because of side effects, drug interactions, medical conditions, or the need for a simpler regimen. In this study, we evaluated people living with HIV whose virus was already well controlled and who changed treatment to a single-tablet regimen containing bictegravir, emtricitabine, and tenofovir alafenamide during routine clinical care at a hospital in Milan, Italy. The study included 799 adults, many of whom were older, had other medical conditions, and were taking additional medications. Most participants maintained viral control after changing treatment. At 12 months, 98% of participants with available data still had undetectable levels of HIV in their blood. The treatment was generally well tolerated, with few adverse events and few treatment interruptions related to safety. Body mass index did not show a clinically relevant change during follow-up, although data were not available for all participants. We also evaluated people who switched from a rilpivirine-based regimen, and their outcomes were similar. These findings support the use of bictegravir, emtricitabine, and tenofovir alafenamide as a treatment-switch option in routine clinical practice, including for people with other medical conditions or multiple medications.