Four days/week antiretroviral maintenance strategy (ANRS 170 QUATUOR): substudies of reservoirs and ultrasensitive drug resistance

Abstract Background In a 4 days/week (4/7 days) maintenance strategy (ANRS-170 QUATUOR trial), the virological impact of an intermittent strategy was assessed by ultrasensitive virological analyses of reservoirs and resistance. Methods HIV-1 total DNA, ultra-sensitive plasma viral load (USpVL) and semen VL were measured in the first 121 participants. Sanger and ultra-deep sequencing (UDS) were performed on the HIV-1 genome (Illumina technology) according to the ANRS consensus. A generalized estimation equation with a Poisson distribution was used to compare changes in the proportion of residual viraemia, detectable semen HIV RNA and HIV DNA within and between the two groups over time. Results The proportion of participants with residual viraemia at Day 0 (D0) and Week 48 (W48) was 16.7% and 25.0% in the 4/7 days group and 22.4% and 29.7% in the 7/7 days group, respectively (+8.3% versus +7.3%, P = 0.971). The proportion of detectable DNA (>40 copies/106 cells) at D0 and W48 was 53.7% and 57.4% in the 4/7 days group and 56.1% and 51.8% in the 7/7 days group, respectively (+3.7% versus −4.3%, P = 0.358). Semen HIV RNA was detectable (≥100 copies/mL) in 2.2% of participants at D0 and 4.5% at W48 in the 4/7 days group versus 6.1% and 9.1% in the 7/7 days group, respectively (+2.3% versus +3.0%, P = 0.743). Emerging resistance at failure was more frequent in the 4/7 days group detected by Sanger sequencing: 3/6 participants versus 1/4 in the 7/7 days group, and similar with the UDS assay: 5/6 versus 4/4, respectively. Conclusions These findings support the potency of a 4/7 days maintenance strategy on virological suppression at the reservoirs and emergent resistance level, including minority variants.