Simultaneous plasma and genital pharmacokinetics and pharmacodynamics of atazanavir and efavirenz in HIV-infected women starting therapy

Pharmacogenetics of Efavirenz Exposure in Cervicovaginal Fluid during Pregnancy and Postpartum

In this study, we investigated the combined influence of pregnancy and genetic polymorphisms on efavirenz pharmacokinetics in cervicovaginal fluid (CVF) of women receiving antiretroviral therapy. Women receiving efavirenz-containing antiretroviral therapy were recruited from two hospitals in Nigeria during 2017-2020. Sparse CVF and plasma samples were obtained during pregnancy to assess the possible association between drug concentration and CYP2B6 polymorphisms (stage I). Participants were stratified into three CYP2B6 516G>T (rs3745274) genotype groups and re-enrolled for intensive pharmacokinetic sampling (stage II). Overall, 159 women (142 pregnant and 12 postpartum) contributed samples in stage I (88 CVF, 81 plasma and 73 paired). CYP2B6 516G>T (rs3745274) remained independently associated with log10 efavirenz CVF concentration during pregnancy after adjusting for plasma concentration, with β (Log10 efavirenz concentration, 95%CI) of 0.204 (0.027, 0.382), P = 0.025). Median (IQR) efavirenz Cmin in CVF during pregnancy (n = 12) vs. postpartum (n = 12) was 243 ng/mL (168-402) vs. 447 ng/mL (159-974), Cmax was 1,031 ng/mL (595-1,771) vs. 1,618 ng/mL (675-2,695), and AUC0-24h was 16,465 ng.h/mL (9,356-30,417) vs. 30,715 ng.h/mL (10,980-43,714). CVF-to-plasma AUC ratio was 0.36 during pregnancy and 0.46 postpartum. Upon stratification, efavirenz clearance during pregnancy was 57.9% higher than postpartum in patients with the CYP2B6 516GT genotype; the AUC0-24h and Cmax were 33.8% and 8.6% lower, respectively. Efavirenz Cmin in CVF exceeded the protein binding-adjusted IC90 (PBIC90) of 126 ng/mL during pregnancy and postpartum. Efavirenz is well distributed into the CVF; both pregnancy and CYP2B6 polymorphisms affect the extent of exposure.

In vitro antibacterial activity of antiretroviral drugs on key commensal bacteria from the human microbiota

Introduction

Antiretroviral therapy has improved life expectancy in HIV-infected patients. However, people living with HIV under antiretroviral therapy are at higher risks of developing chronic complications and acquiring multidrug resistant bacteria than healthy population. These factors have been associated with shifts in gut microbiome composition and immune activation. It is unclear how antiretroviral drugs affect gut microbiota composition, but it has been observed that antiretroviral treatment is not able to fully restore gut health after HIV infection. Additionally, some antiretroviral drugs have shown antibacterial activity suggesting that these drugs could have a direct impact on the human microbiome composition.

Methods

We determined the in vitro antibacterial activity of 16 antiretroviral drugs against a set of key clinically relevant and human commensal bacterial strains.

Results

Our results demonstrate that 5 antiretroviral drugs have in vitro antibacterial activity against gut and vaginal human commensal bacteria. Zidovudine has antibacterial activity against Escherichia coli, Klebsiella pneumoniae and Prevotella bivia, abacavir against Gardnerella vaginalis, efavirenz against G. vaginalis and P. bivia and bictegravir against Enterococcus spp. and G. vaginalis. Moreover, we describe for the first time that elvitegravir has antibacterial activity against G. vaginalis and P. bivia and, most importantly, against vancomycin-resistant Enterococcus spp. and methicillin-resistant Staphylococcus aureus strains with MIC values of 4-16 and 4 µg/mL, respectively showing high level of effectiveness against the tested multidrug-resistant bacteria.

Discussion

Our results underscore that some antiretroviral drugs may influence the human microbiota composition. In addition, we report the potential use of elvitegravir to treat multidrug-resistant Gram-positive bacteria warranting the need of clinical studies to repurpose this antiretroviral drug.

Decay kinetics of HIV-1-RNA in seminal plasma with dolutegravir/lamivudine versus dolutegravir plus emtricitabine/tenofovir alafenamide in treatment-naive people living with HIV

BACKGROUND

This was a substudy of a Phase IV, randomized clinical trial (ClinicalTrials.gov identifier: NCT04295460) aiming to compare the activity of dolutegravir/lamivudine versus dolutegravir plus tenofovir alafenamide/emtricitabine (DTG + TAF/FTC) in the male genital tract.

METHODS

Participants were asymptomatic adults without sexually transmitted diseases, treatment-naive people living with HIV (PLWH), with CD4+ T cell counts >200 cells/mm3 and plasma HIV-1-RNA levels >5000 and <500 000 copies/mL, randomized (1:1) to DTG + TAF/FTC or dolutegravir/lamivudine. Blood plasma (BP) and seminal plasma (SP) were collected at baseline and Weeks 4, 8, 12 and 24. HIV-1-RNA was measured in BP and SP using the Cobas 6800 system (Roche Diagnostics) with a lower detection limit of 20 copies/mL. The primary efficacy endpoint was the proportion of subjects with undetectable SP HIV-1-RNA at Week 12 by intention-to-treat analysis.

RESULTS

Fifteen participants in the DTG + TAF/FTC and 16 in the dolutegravir/lamivudine arms were analysed, with basal SP viral load of 4.81 (4.30-5.43) and 4.76 (4.09-5.23), P = 0.469, respectively. At Week 12, only one participant in each treatment arm had a detectable SP HIV-1-RNA (DTG + TAF/FTC, 141 copies/mL; dolutegravir/lamivudine, 61 copies/mL). Based on the estimated means, there was no significant difference in the decay of HIV-1-RNA in both BP and SP over time between the two arms of treatment (F = 0.452, P = 0.662, and F = 1.147, P = 0.185, respectively).

CONCLUSIONS

After 12 weeks of treatment, there were no differences in the percentage of undetectable SP HIV-1-RNA in naive PLWH who started dolutegravir/lamivudine compared with DTG + TAF/FTC.