Comparison of viral replication for the 2-drug regimen (2DR) of dolutegravir/lamivudine (DTG/3TC) versus a 3/4-drug tenofovir alafenamide'based regimen (TBR) in the TANGO study through week 96


BACKGROUND: TANGO demonstrated non-inferior virologic efficacy (HIV-1 RNA '¥50 c/mL, Snapshot) of switching to DTG/3TC vs continuing TBR in HIV-1-infected, virologically suppressed adults at 96 weeks. Abbott RealTime HIV-1 assay measures viral load (VL) from 40 to 10,000,000 c/mL, and provides qualitative target detected (TD) or target not detected (TND) outcomes for VL <40 c/mL. Clinical significance of low-level VL <50 c/mL remains unclear. We assessed proportion of participants with TD/TND and elevated VL through Week 96 (Wk96).
METHODS: Proportions of participants with VL <40 c/mL and TND were analysed by visit (Snapshot) through Wk96. Participants' TD/TND status over time, overall and by Baseline VL classifications, was assessed. Frequency of elevated VL categories including 'blips' was determined.
RESULTS: At Wk96, similar proportions of participants had TND with 2DR and 3DR (73% [271/369] vs 69% [255/372], respectively; adjusted difference, 4.9%; 95% Cl, '1.7, 11.4; Snapshot). Across Baseline VL categories, proportions with TND at all visits through Wk96 were higher at 37% (137/369) with 2DR vs 31% (114/372) with 3DR (Table 1). Occurrence of elevated VL (Table 2) was low and similar across arms through Wk96, and most frequently observed VL rebounds were 'blips.' Zero and 3 confirmed virologic withdrawals were observed with 2DR and 3DR, respectively.

CONCLUSIONS: Similar proportions of participants had TND at all visits through Wk96 in both treatment arms. Regardless of Baseline VL, incidence of intermittent viremia was low and similar between arms. These 'deep dive' virology findings further support the potency and durability of 2DR vs 3DR in maintaining viral suppression.