Effectiveness and Safety of Darunavir/Cobicistat Plus Lamivudine Compared With Darunavir/Cobicistat Plus Tenofovir Alafenamide/Emtricitabine in Virologically Suppressed People Living With HIV at 24 and 48 Weeks of Follow-up

This was a phase IV, open-label, single-center pilot clinical trial conducted from March 2025 to March 2026 at the HIV Clinic of the "La Raza" Infectious Diseases Hospital, National Medical Center, in Mexico City. This tertiary care center provides services to patients with social security coverage. The study protocol was approved by the Local Health Research Committee of the Mexican Social Security Institute (3502) and the Research Ethics Committee (35028; R-2025-3502-183). Written informed consent was obtained from all participants to mantained DRV/c + 3TC or switching from TDF/FTC to TAF/FTC.

Study population: Eligible participants were adult males ≥18 years old living with HIV-1 who had maintained virological suppression on either dual therapy with DRV/c + 3TC or triple therapy with DRV/c + TDF/FTC for 48 weeks prior to enrollment (TLALOC-1 trial), and had an estimated glomerular filtration rate (eGFR) ≥60 mL/min/1.73 m² calculated by the CKD-EPI equation.

Exclusion criteria in TLALOC-1 included history of prior virological failure, baseline genotypic resistance mutations to any component of the study regimens, active malignancy, or coinfection with hepatitis B virus (HBV) or hepatitis C virus (HCV).

Treatment allocation:This was a non-randomized study. Participants already receiving DRV/c + 3TC (1 tablet of DRV/c 800/150 mg and two tablets of 3TC of 150 mg each) continued on the same dual regimen. Participants receiving DRV/c + TDF/FTC switched the nucleoside backbone from TDF/FTC to TAF/FTC 10/200 mg while continuing DRV/c.

Outcomes: For this preliminary analysis, the primary efficacy endpoint was the proportion of participants with HIV-1 RNA ≥50 copies/mL at week 24. (TLALOC-2 continues recruitment; the primary endpoint for the full study is effectiveness and safety at 48 and 96 weeks of follow-up). This was confirmed in two consecutive determinations, according to the FDA Snapshot algorithm. Participants were classified into three mutually exclusive categories.