Efficacy and safety profiles of dolutegravir plus lamivudine vs. bictegravir/emtricitabine/tenofovir alafenamide in therapy-naïve adults with HIV-1

BACKGROUND: Dual regimen dolutegravir (DTG) plus lamivudine (3TC) has demonstrated non-inferior efficacy compared to DTG-based three-drug regimens (3DRs), yet directly comparative data regarding the efficacy and safety of DTG + 3TC and bictegravir/emtricitabine/tenofovir alafenamide (B/F/TAF) for therapy-naïve people with human immunodeficiency virus (HIV)-1 (PWH) are still limited. We aimed to assess the antiviral potency and safety profiles of DTG + 3TC vs. B/F/TAF based on antiretroviral therapy (ART)-naïve PWH in China. METHODS: This retrospective multicenter study enrolled PWH initiating ART with DTG + 3TC or B/F/TAF from 2020 to 2022 in Guangdong and Guangxi. We analyzed response rates based on target not detected (TND) status using intention-to-treat (ITT) analysis. Subgroups were formed based on baseline viral load (VL) (<100,000 vs. ≥100,000 copies/mL) and CD4(+) cell count (<200 vs. ≥200 cell/µL). Median time to TND VL was assessed by Kaplan–Meier method. We also measured changes from baseline in CD4(+) cell counts, CD4/CD8 ratio, lipid parameters, weight, creatinine (Cr), estimated glomerular filtration rate (eGFR), and drug-related adverse effects (DRAEs). RESULTS: We enrolled 280 participants, including 137 (48.9%) on DTG + 3TC and 143 (51.1%) on B/F/TAF. At week 48, 96.4% (132/137) on DTG+3TC and 100% (143/143) on B/F/TAF achieved TND (P = 0.064). At week 12, TND responses were higher with B/F/TAF (78.3% [112/143]) than DTG+3TC (30.7% [42/137]) (P <0.001). This trend held across subgroups. B/F/TAF achieved TND faster (12 weeks) than DTG+3TC (24 weeks) (P <0.001). No differences were seen in CD4(+) cell count and CD4/CD8 ratio, except in the high-VL subgroup, where B/F/TAF showed better recovery. DRAEs were significantly lower with B/F/TAF (4.9% [7/143]) than with DTG + 3TC (13.1% [18/137]) (P = 0.016). Lipid parameters, body weight, and Cr increased in both groups over 48 weeks, with DTG+3TC showing a more favorable effect on triglycerides, high-density lipoprotein (HDL) cholesterol, and weight gain. CONCLUSIONS: In this real-life study, B/F/TAF led to a faster viral decline and fewer DRAEs compared to DTG+3TC. No significant difference was observed in the TND rate at week 48, regardless of baseline VL and CD4(+) cell count. CD4(+) recovery was superior for B/F/TAF in participants with high VL. The DTG + 3TC regimen had less impact on metabolic changes than B/F/TAF.