ANRS 170 QUATUOR study demonstrated the non-inferiority of a 4/7 days maintenance strategy vs a 7/7 days regimen in patients with controlled viral load (VL) under triple therapy with either PI, NNRTI, or InSTI based regimen at week 48 (W48). The aims of these virological sub-studies were to assess HIV cellular reservoir size, HIV residual viremia and HIV RNA quantification in semen until W48.
HIV total DNA was measured using the real-time PCR kit GENERIC HIVDNA Cell® (Biocentric®, Bandol, France) with a limit of quantification [LOQ] of 10 copies/PCR. Ultra-sensitive plasma VL (USpVL) and semen HIV VL (1/5 dilution) were determined using COBAS® HIV-1, v2.0 (Roche Molecular Systems, Branchburg, NJ, USA). For USpVL, the limit of detection (LOD) was defined as an undetected PCR signal. Generalized estimating equation was used to compare the changes from baseline of total HIV DNA, plasma seminal VL and plasma blood residual viremia within and between the 2 groups over time.
Characteristics of sub-study population were similar to those of global trial population. Paired D0 and W48 HIV total DNA were obtained in 119 patients. 45% and 44% of patients showed a HIV DNA below the LOQ at D0 and W48 respectively. Median (IQR) HIV DNA was 1.7 log10 c/106 PBMC (<1.3-2.3) at D0 and 1.6 (<1.3-2.4) at W48 in the 4D arm versus 1.9 (<1.3-2.3) and 1.7 (<1.3-2.3) in the 7D arm. Plasma residual viremia was measured in 116 patients at D0 and W48 with a proportion of patients with USpVL detectable of 17.3 % and 26.9% respectively in the 4D arm and 21.9% and 29.7 % in the 7D arm. Semen HIV RNA was measured in 78 patients with a proportion of semen VL detectable in 2.3% at D0 and 6.7% at W48 in the 4D arm versus 6.1% and 9.1 % in the 7D arm. There is no significant evolution in HIV DNA, residual viremia and semen VL between D0 and W48 and no significant difference between arms.
No change was observed during the first year of 4/7 days maintenance therapy in plasma residual viremia level or in HIV cellular reservoir size, as in the 7/7 days. These findings are reassuring the potency of a 4D/7 maintenance strategy on virological suppression at the level of residual viremia.