Use of PCR Signal and Therapeutic Drug Monitoring in a Switch Cohort Study to Tenofovir/Emtricitabine/Rilpivirine: A W96 Follow-Up

Therapeutic drug monitoring and virological response at week 48 in a cohort of HIV-1-infected patients switching to dolutegravir/rilpivirine dual maintenance therapy (ANRS-MIE-BIRIDER study)

AIMS

Dolutegravir (DTG) and rilpivirine (RPV) dual therapy is now recommended as a switch option in virologically suppressed HIV patients. Literature suggests that virological failure with dual therapy could possibly relate to subtherapeutic drug concentrations. In this study, we aimed at describing the DTG and RPV trough plasma concentrations (Cmin) and plasma HIV-1 RNA viral load (VL) during maintenance dual therapy.

METHODS

We performed a retrospective analysis of DTG and RPV therapeutic drug monitoring in people living with HIV/AIDS (PLWHA) with dual therapy in 9 French centres. DTG and RPV trough plasma concentrations were estimated using a Bayesian approach to predict Cmin. The relationship between the pharmacokinetics of DTG and RPV and VL > 50 copies (cp)/mL was explored using joint nonlinear mixed models. The frequency of subtherapeutic threshold (DTG Cmin below 640 ng/mL and RPV Cmin below 50 ng/mL) were compared between PLWHA presenting VL > 50 cp/mL or not during the study.

RESULTS

At baseline, 209 PLWHA were enrolled in the study. At week 48, 19 people living with HIV/AIDS (9.1%) discontinued their treatment and 15 PLWHA (7.1%) exhibited VL > 50 cp/mL. Six PLWHA out of 15 (40.0%) with VL > 50 cp/mL during the follow-up had at least 1 Cmin below the respective thresholds while only 26/194 patients (13.4%) without virological replication had at least 1 concentration below the threshold (P = .015).

CONCLUSION

A majority of PLWHA receiving DTG/RPV maintenance dual therapy demonstrated VL < 50 cp/mL but virological replication was more frequent in people living with HIV/AIDS with subtherapeutic Cmin.

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

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.

High virological suppression regardless of the genotypic susceptibility score after switching to a dolutegravir-based regimen: week 48 results in an observational cohort

Objectives

To assess, in a clinical cohort, the efficacy of switching current ART in virologically suppressed patients to a dolutegravir-based regimen, regardless of the genotypic susceptibility score (GSS).

Patients and methods

This was an observational single-centre study assessing ART-treated patients with plasma viral load (pVL) <50 copies/mL who were switched to a dolutegravir-based regimen with 1 year of follow-up. PCR negative was defined as an undetected PCR signal. Trough plasma concentration (C24) was determined using UPLC-MS/MS.

Results

Two hundred and thirty-nine patients initiated a dolutegravir-based regimen: 12%, 29% and 59% had a total GSS of 1 or 1.5 (group 1), 2 or 2.5 (group 2) and 3 (group 3), respectively. At switch initiation, the median time since first ART and the median duration with pVL <50 copies/mL were 13 years (IQR = 6-19) and 3 years (IQR = 1-6), respectively. Median times since last genotype were 9, 10 and 5 years for groups 1, 2 and 3, respectively. Twenty patients (8.4%) discontinued the dolutegravir-based regimen due to adverse events. During the study, 96.4% (n = 661/686) of all pVL were <50 copies/mL. Four patients (1.7%) experienced virological failure (two pVL >50 copies/mL) without emergence of resistance; these patients' GSSs were 2, 2.5, 3 and 3. The median dolutegravir C24 was 1545 ng/mL (IQR = 1150-2097). Of the patients with pVL <20 copies/mL, 72% were PCR negative during the follow-up, with no difference between the three groups of patients.

Conclusions

This observational cohort study showed a high level of virological suppression maintenance in the first year following the switch to a dolutegravir-based regimen, even in patients with GSS ≤2.

Switch as maintenance to elvitegravir/cobicistat/emtricitabine/tenofovir disoproxil fumarate: week 48 results in a clinical cohort

Objectives

To assess, in a clinical cohort, the efficacy of switching current ART in virologically suppressed patients to elvitegravir/cobicistat/emtricitabine/tenofovir disoproxil fumarate as a single-tablet regimen (STR) using the PCR signal of the plasma viral load (pVL) assay and determination of plasma drug concentration ( C 24 ).

Patients and methods

This was an observational single-centre study enrolling antiretroviral-treated patients with pVL <50 copies/mL initiating elvitegravir-based STR. PCRneg was defined as an undetected PCR signal.

Results

One hundred and fifty-one patients were enrolled. At STR baseline, the median time since first ART and time of virological suppression were 5 years (IQR 3-9) and 24 months (IQR 9-44), respectively. By week (W) 48, 26 (17%) of the patients had discontinued STR due to adverse events. The proportion of patients maintaining pVL <50 copies/mL on treatment was 98%, 96%, 93% and 97% at W12, W24, W36 and W48, respectively. Five patients (3.3%) experienced a virological failure and emergence of resistance was observed in two of them with the selection of M184V and N155H mutations. At baseline, W12, W24, W36 and W48, 70%, 57%, 72%, 61% and 74% of the patients with pVL <20 copies/mL had a PCRneg, respectively. The median elvitegravir plasma C 24 value was 648 ng/mL (IQR 348-989; n  =   237), with 84% of elvitegravir C 24 values >45 ng/mL, the protein-adjusted IC 95 .

Conclusions

In this clinical cohort of virologically suppressed patients switching to STR, most subjects had adequate elvitegravir C 24 values with a high proportion maintaining virological suppression with no residual viraemia until W48.