Bictegravir/emtricitabine/tenofovir alafenamide for primary HIV infection: Efficacy, safety and impact on viral reservoir (the BIC-PHI clinical trial)

OBJECTIVES: We evaluated the efficacy, safety and impact on viral reservoir of rapid bictegravir/emtricitabine/tenofovir alafenamide (BIC/FTC/TAF) initiation during primary HIV infection (PHI). METHODS: Multicenter, single-arm clinical trial in participants with PHI of <3 months (seroconversion or incomplete serological pattern), starting BIC/FTC/TAF in 6 Spanish centers between January-2021 and September-2022. Primary endpoint was proportion of participants with viral load (VL)<50 copies/mL at 48-weeks on the Intention-to-treat-exposed population (ITTe). Cases were compared with randomly-matched retrospective PHI controls, starting other 3-drug Integrase-Strand-Transfer-inhibitor-based regimens. Reservoir was evaluated in PHI cases by Intact Proviral DNA Assay (IPDA). RESULTS: We included 64 participants, 94% cis-male, aged 32 (26;41) years.; 78% men-who-have-sex-with-men. At BIC/FTC/TAF initiation, Fiebig stages were II (14%), III (11%); IV (5%), V (54%) and VI (16%); VL was 496,520 (110,000;1,285,000) copies/mL; 62% were subtype B; median (IQR) CD4 T cell count was 406 (322;535) cells/µL; 6% had active hepatitis B virus co-infection. All participants started BIC/FTC/TAF at first specialist consultation. 81% (ITTe) and 93% (On-Treatment, OT) had VL<50 copies/mL at 48-weeks. 72% had adverse events, only 3% were grade 3/4; 91% were not-related, none led to BIC/FTC/TAF-discontinuation. 92% of controls (OT) had VL<50 copies/mL at 48-weeks (p=0.914), 11% (17%) modified initial antiretroviral regimen (p>0.001). Intact and defective proviral DNA levels significantly decreased at 48-weeks. CONCLUSIONS: BIC/FTC/TAF showed rapid viral decay, high suppression rates, good tolerability, and reservoir decline in PHI, making it an appealing regimen in this setting.