Effectiveness of a direct switch to Bictegravir/Emtricitabine/Tenofovir alafenamide in people living with HIV experiencing first-line treatment failure: a real-world study

In China, Non-Nucleoside Reverse Transcriptase Inhibitor (NNRTI)- or Protease Inhibitor (PI)/boosted regimens with two Nucleoside Reverse Transcriptase Inhibitors (NRTIs) are common first-line Antiretroviral Therapy (ART) for People living with HIV (PLWH). Genotypic resistance testing is often unavailable or delayed after treatment failure. The effectiveness of direct switch to Bictegravir/Emtricitabine/Tenofovir Alafenamide (B/F/TAF) following first-line failure in Chinese PLWH is uncertain and requires further investigation. A total of 68 PLWH with plasma HIV RNA > 200 copies/mL while receiving first-line ART were directly switched to B/F/TAF between January 2022 and December 2023. Genotypic resistance testing was performed in individuals with viral load (VL) > 1000 copies/mL. Virologic suppression, CD4 cell recovery, and adverse events were evaluated at week 24 (W24) and 48 (W48). There were 61 (90%) on NNRTI-based regimens and 7 (10%) on PI-based regimens at baseline. Among 49 individuals with VL > 1000 copies/mL, 21(42.9%) had NRTI RAMs, 26(53.0%) had NNRTI RAMs, 3(6.1%) had PI-related mutations. The intention-to-treat (ITT) analysis indicated the virologic suppression rate was 61.7% (42/68) at W24 and 72.1%(49/68) at W48. Meanwhile, the per-protocol (PP) analysis indicated the virologic suppression rate was 93.3%(42/45) at W24 and 100% (49/49) at W48. Notably, the cohort included participants with pre-existing NRTI/NNRTI RAMs. Most mutation carriers achieved virologic suppression after regimen switching.The median CD4 count was increased from 199 [interquartile range(IQR): 85–347] cells/µL at W0 up to 346 (IQR: 178–507) cells/µL at W24 and 410(IQR:200–577) cells/µL at W48 ( P = 0.002, P < 0.001, respectively). Our study indicated that direct switch to B/F/TAF after first-line treatment failure achieved 72.1% virological suppression rate in ITT analysis and 100% virologic suppression rate in PP analysis at W48, suggesting that B/F/TAF may serve as an effective salvage therapy for PLWH with pre-existing NRTI RAMs in China in the setting of genotypic resistance testing is unavailable timely.