Incidence and impact of low-level viremia among people living with HIV who received protease inhibitor- or dolutegravir-based antiretroviral therapy

OBJECTIVES

The impact of very low-level viremia (VLLV) and low-level viremia (LLV) are rarely investigated among people living with HIV (PLWH) receiving dolutegravir- vs protease inhibitor (PI)-based antiretroviral therapy (ART).

METHODS

Virally suppressed PLWH receiving long-term PI-containing ART were included in this study. The incidences of developing VLLV (plasma HIV RNA load (PVL) 20-49 copies/ml), LLV (PVL 50-999 copies/ml), and virological failure (any PVL ≥ 1000 copies/ml) were compared between those switched to dolutegravir-based ART and those remaining on PI-containing ART.

RESULTS

A total of 183 PLWH were switched to dolutegravir-based regimens and 309 remained on PI-containing regimens. The incidences of VLLV and LLV were 26.5 and 13.2 per 100 person-years of follow-up in the dolutegravir group, respectively, and 17.1 and 7.0 per 100 person-years of follow-up in the PI group; there were no statistically significant differences after adjusting for confounders. The rate of virological failure was 1.3 per 100 person-years of follow-up in the dolutegravir group and 1.9 per 100 person-years of follow-up in the PI group (p = 0.32). Neither VLLV nor LLV was related to subsequent virological failure.

CONCLUSIONS

Among virally suppressed PLWH, the risk of developing VLLV or LLV were similar between those switched to dolutegravir-based therapy and those who continued PI-based therapy. VLLV and LLV were not associated with subsequent virological failure.

Effect of dolutegravir in combination with Nucleoside Reverse Transcriptase Inhibitors (NRTIs) on people living with HIV who have pre-existing NRTI mutations

Until the introduction of dolutegravir (DTG), people living with HIV (PLWH) who have developed nucleoside reverse transcriptase inhibitor (NRTI) mutations have had few other treatment options outside of regimens based on ritonavir-boosted protease inhibitors (PI/r). Here we report treatment results among PLWH in Sweden with pre-existing NRTI mutations on antiretroviral treatment (ART) with DTG and one to two NRTIs. All PLWH on ART with DTG and one to two NRTIs with pre-existing NRTI mutations were retrospectively identified from the National InfCare HIV database. As controls, PLWH on PI/r and one to two NRTIs, matched according to Genotypic Susceptibility Score and observation time, were included. Data were collected as long as the study population was on treatment with DTG; controls were monitored for the same interval. Outcome was classified as either treatment success or failure. In total, 244 participants (122 individuals treated with DTG and 122 individuals treated with PI/r) were included. Median observation time was 78 weeks (interquartile range 50-98 weeks) for participants on DTG and 75 weeks (50-101 weeks) for individuals on PI/r. Viral failure was detected in four individuals treated with DTG and three individuals treated with PI/r, resulting in similar success rates of 96.7% and 97.5%, respectively. No new mutations were found among participants with treatment failure. DTG in combination with one to two NRTIs was as efficient as PI/r in individuals with pre-existing NRTI mutations in this setting. It may be considered an alternative to PI/r-based ART even in the presence of NRTI resistance.

Evaluation of nucleoside reverse transcriptase inhibitor dosing during continuous veno-venous hemofiltration

Background Unpredictable drug concentrations may lead to suboptimal exposure to nucleoside reverse transcriptase inhibitors (NRTIs) due to inadequate doses administered during continuous veno-venous hemofiltration (CVVH), which in turn may lead to decreased antiretroviral efficacy and possibly further HIV disease progression. Objective To compare administered doses of NRTIs to calculated doses of NRTIs to evaluate if patients were expected to have a favorable pharmacokinetic exposure profile while receiving CVVH. Methods The NRTI dose was compared to a table of recommendations based on a mathematical formula that estimates the amount of drug expected to be removed during CVVH. Results Twelve patients were on 27 NRTIs. Eleven (41%) NRTI doses were expected to provide a favorable pharmacokinetic profile based on pharmacokinetic mathematical calculations. Conclusion The majority of NRTIs were potentially not optimally dosed based on proposed pharmacokinetic calculations.