Cytokine and sex hormone effects on zidovudine- and lamivudine-triphosphate concentrations in vitro

Pharmacokinetics and Safety of Remdesivir in Pregnant and Nonpregnant Women With COVID-19: Results From IMPAACT 2032

BACKGROUND

Pregnant people with coronavirus disease 2019 (COVID-19) experience higher risk for severe disease and adverse pregnancy outcomes, but no pharmacokinetic (PK) data exist to support dosing of COVID-19 therapeutics during pregnancy. We report PK and safety data for intravenous remdesivir in pregnancy.

METHODS

IMPAACT 2032 was a phase 4 prospective, open-label, nonrandomized opportunistic study of hospitalized pregnant and nonpregnant women receiving intravenous remdesivir as part of clinical care. Intensive PK sampling was performed on infusion days 3, 4, or 5 with collection of plasma and peripheral blood mononuclear cells (PBMCs). Safety data were recorded from first infusion through 4 weeks after last infusion and at delivery. Geometric mean ratios (GMR) (90% confidence intervals [CI]) of PK parameters between pregnant and nonpregnant women were calculated.

RESULTS

Fifty-three participants initiated remdesivir (25 pregnant; median gestational age, 27.6 weeks; interquartile range, 24.9-31.0 weeks). Plasma exposures of remdesivir, its 2 major metabolites (GS-704277 and GS-441524), and the free remdesivir fraction were similar between pregnant and nonpregnant participants. Concentrations of the active triphosphate (GS-443902) in PBMCs increased 2.04-fold (90% CI, 1.35-3.03) with each additional infusion in nonpregnant versus pregnant participants. Three adverse events in nonpregnant participants were related to treatment (1 grade 3; 2 grade 2 resulting in treatment discontinuation). There were no treatment-related adverse pregnancy outcomes or congenital anomalies detected.

CONCLUSIONS

Plasma remdesivir PK parameters were comparable between pregnant and nonpregnant women, and no safety concerns were identified based on our limited data. These findings suggest no dose adjustments are indicated for intravenous remdesivir during pregnancy.

CLINICAL TRIALS REGISTRATION

NCT04582266.

Factors associated with tenofovir diphosphate concentrations in dried blood spots in persons living with HIV

OBJECTIVES

To determine factors associated with interindividual variability in tenofovir diphosphate (TFV-DP) concentrations in dried blood spots (DBSs) among persons living with HIV (PLWH).

METHODS

PLWH who were at least 18 years old and taking tenofovir disoproxil fumarate-containing ART were prospectively recruited and enrolled from a clinical cohort and followed longitudinally (up to three visits over 48 weeks). With log-transformed TFV-DP concentrations in DBSs as the outcome, mixed-model regression analyses were used to assess associations between self-reported 3 month ART adherence, race and other clinical covariates (gender, age, BMI, CD4+ T cell count, estimated glomerular filtration rate, haematocrit, duration on current ART and anchor drug class) on TFV-DP in DBSs.

RESULTS

Five hundred and twenty-seven participants (1150 person-visits) were analysed. Adjusting for race and other clinical covariates, every 10% increase in self-reported 3 month ART adherence was associated with an average TFV-DP concentration increase in DBSs of 28% (95% CI: 24%-32%; P < 0.0001). In the same model, female participants had 20% (95% CI: 3%-40%; P = 0.02) higher TFV-DP concentrations in DBSs, compared with male participants, and every 1 kg/m2 increase in BMI was associated with a decrease in TFV-DP concentration in DBSs by 2% (95% CI: -3% to -1%; P < 0.0001).

CONCLUSIONS

Individual patient characteristics were predictive of TFV-DP concentration in DBSs in PLWH receiving tenofovir disoproxil fumarate-based ART. Future research to incorporate these predictors into the interpretation of this ART adherence biomarker, and to establish whether these associations extend to PLWH taking tenofovir alafenamide-containing ART, is needed.

Depot Medroxyprogesterone Acetate and the Vaginal Microbiome as Modifiers of Tenofovir Diphosphate and Lamivudine Triphosphate Concentrations in the Female Genital Tract of Ugandan Women: Implications for Tenofovir Disoproxil Fumarate/Lamivudine in Preexposure Prophylaxis

BACKGROUND

Effective concentrations of antiretrovirals in the female genital tract (FGT) are critical for suppression of viral shedding or effective preexposure prophylaxis. The disposition of tenofovir diphosphate (TFV-DP) and emtricitabine triphosphate (FTC-TP) in the FGT have been previously described. Despite widespread use, however, lamivudine triphosphate (3TC-TP) exposure in the FGT is unknown. Depot medroxyprogesterone acetate (DMPA) and vaginal dysbiosis have been implicated in increased risk of human immunodeficiency virus (HIV) acquisition, but whether they alter TFV-DP or 3TC-TP exposure, and therefore compromise prevention efficacy, is unknown.

METHODS

Fifty premenopausal women living with HIV in Kampala, Uganda, and receiving daily tenofovir disoproxil fumarate/lamivudine were recruited. Ectocervical biopsies were obtained for quantification of TFV-DP and 3TC-TP using liquid chromatography-mass spectrometry. 16S ribosomal RNA gene sequencing was performed on DNA extracted from vaginal swabs. Wilcoxon rank-sum was used to test for differences between contraceptive groups.

RESULTS

3TC-TP concentrations were on average 17-fold greater than TFV-DP concentrations in cervical tissues. TFV-DP concentrations in cervical biopsies were 76% greater in DMPA users compared with women using nonhormonal contraception (n = 23 per group). Abundance of Lactobacillus in vaginal swabs was correlated with 3TC-TP concentrations in cervical tissues.

CONCLUSIONS

We found that TFV-DP concentrations were significantly greater in DMPA users compared with women using nonhormonal contraception, suggesting that prevention efficacy is unlikely to be compromised by DMPA use. Similar to reports of FTC-TP, 3TC-TP exposure was significantly greater than TFV-DP in cervical tissue and was correlated with abundance of Lactobacillus. These data support lamivudine as an option for preexposure prophylaxis.

CLINICAL TRIALS REGISTRATION

NCT03377608.

Pharmacokinetic and Pharmacodynamic Impacts of Depot Medroxyprogesterone Acetate Use on HIV Pre-exposure Prophylaxis in Women

BACKGROUND

Depot medroxyprogesterone acetate (DMPA) is a commonly used contraceptive in areas where use of tenofovir disoproxil fumarate and emtricitabine for HIV pre-exposure prophylaxis (PrEP) is increasing.

OBJECTIVES

We aimed to investigate the impact of DMPA on PrEP drug pharmacokinetics and pharmacodynamics in women using PrEP before and after DMPA administration.

METHODS

In this pilot study, 12 HIV-negative women ages 18-45 underwent biological sample collection at 3 time points: before study drug, after 2 weeks of daily PrEP use alone, and after 2 weeks of daily PrEP and concomitant DMPA use. We measured drug and drug metabolites in plasma, peripheral blood mononuclear cells, cervicovaginal fluid, cervical tissue, and rectal fluid after each 2-week course of PrEP. We measured HIV replication ex vivo in genital tissue biopsies and innate anti-HIV activity in cervicovaginal fluid before PrEP and after both courses. We compared drug concentrations after PrEP alone to after PrEP and DMPA in the same participant using Wilcoxon signed-rank tests. We used mixed effects linear regression models to compare pharmacodynamic measures for each participant at predrug baseline, after PrEP alone, and after PrEP and DMPA.

RESULTS

We found no significant differences in PrEP drug and drug metabolite concentrations in any compartment during concomitant DMPA use compared with use of PrEP alone, except for a reduction in emtricitabine concentration in cervical tissue. We found no difference in HIV replication in cervical tissue or anti-HIV activity in cervicovaginal fluid during concomitant DMPA and PrEP use compared with during PrEP use alone.

CONCLUSIONS

Concomitant use of DMPA does not clinically alter pharmacokinetics or pharmacodynamics of PrEP in women. These data support the safety of DMPA use in women using PrEP.

Pharmacologic Considerations for Preexposure Prophylaxis in Transgender Women

Studies of tenofovir disoproxil fumarate (TDF)-emtricitabine (FTC)-based preexposure prophylaxis (PrEP) have not focused on transgendered women who are at disproportionate risk of HIV acquisition. Concerns exist for drug interactions between cross-sex therapy (estradiol, progestins, and spironolactone) with tenofovir disoproxil fumarate-emtricitabine. This review assessed the experimental and theoretical risk for such drug interactions. It was found that none of these medications are implicated as major perpetrators of drug interactions, and the classes use different metabolic pathways for clearance, suggesting a low likelihood for interactions in either direction. Subanalyses of transgender women in Preexposure Prophylaxis Initiative suggested PrEP efficacy if adherence was high. Nevertheless, several research gaps were identified, particularly the need for controlled interaction studies in transgendered women, including effects on renal clearance, intracellular tenofovir diphosphate and emtricitabine triphosphate in target cells, as well as hormone effects on HIV susceptibility and immunity. PrEP should continue to be offered to transgender women while additional research is planned or pending.

Concentrations of Pro-Inflammatory Cytokines Are Not Associated with Senescence Marker p16INK4a or Predictive of Intracellular Emtricitabine/Tenofovir Metabolite and Endogenous Nucleotide Exposures in Adults with HIV Infection

OBJECTIVES

As the HIV-infected population ages, the role of cellular senescence and inflammation on co-morbid conditions and pharmacotherapy is increasingly of interest. p16INK4a expression, a marker for aging and senescence in T-cells, is associated with lower intracellular concentrations of endogenous nucleotides (EN) and nucleos(t)ide reverse transcriptase inhibitors (NRTIs). This study expands on these findings by determining whether inflammation is contributing to the association of p16INK4a expression with intracellular metabolite (IM) exposure and endogenous nucleotide concentrations.

METHODS

Samples from 73 HIV-infected adults receiving daily tenofovir/emtricitabine (TFV/FTC) with either efavirenz (EFV) or atazanavir/ritonavir (ATV/r) were tested for p16INK4a expression, and plasma cytokine and intracellular drug concentrations. Associations between p16INK4a expression and cytokine concentrations were assessed using maximum likelihood methods, and elastic net regression was applied to assess whether cytokines were predictive of intracellular metabolite/endogenous nucleotide exposures.

RESULTS

Enrolled participants had a median age of 48 years (range 23-73). There were no significant associations between p16INK4a expression and cytokines. Results of the elastic net regression showed weak relationships between IL-1Ra and FTC-triphosphate and deoxyadenosine triphosphate exposures, and MIP-1β, age and TFV-diphosphate exposures.

CONCLUSIONS

In this clinical evaluation, we found no relationships between p16INK4a expression and cytokines, or cytokines and intracellular nucleotide concentrations. While inflammation is known to play a role in this population, it is not a major contributor to the p16INK4a association with decreased IM/EN exposures in these HIV-infected participants.

Uptake of tenofovir and emtricitabine into non-monocytic female genital tract cells with and without hormonal contraceptives

Background

Pre-exposure prophylaxis is becoming a strategic component used to control the human immunodeficiency virus (HIV-1) epidemic. The goal of this study was to characterize intracellular uptake of tenofovir and emtricitabine using five surrogate cell lines of the female genital tract and determine whether exogenous hormones influence their uptake.

Methods

Surrogate cell lines, ie, THP-1 (representing macrophages), BC-3 (CD8+), Ect1/E6E7 (squamous epithelial), HeLa (CD4+), and TF-1 (dendritic), were incubated for one hour with tenofovir and emtricitabine to assess uptake. In separate experiments, ethinyl estradiol (EE) and etonogestrel (ET) individually and together (EE/ET) were added prior to, simultaneously, and after incubation. Intracellular phosphorylated tenofovir and emtricitabine were quantified using validated tandem mass spectrometry methods.

Results

HeLa and Ect1/E6E7 cells showed significantly increased uptake relative to THP-1 controls for both antiretrovirals. Individually, ethinyl estradiol and etonogestrel significantly altered antiretroviral uptake across all cell lines, except Ect1/E6E7 for tenofovir and HeLa for emtricitabine. Cellular uptake of tenofovir and emtricitabine in BC-3 and TF-1 cells were significantly lower when dosed one hour prior to EE/ET administration compared with each antiretroviral administered in the absence of EE/ET (tenofovir, 80 versus 470 fmol/10⁶ for BC-3 and 77 versus 506 fmol/10⁶ cells for TF-1; emtricitabine, 36 versus 12 fmol/10⁶ for BC-3 and 75 versus 5 fmol/10⁶ cells for TF-1; P < 0.01 for each).

Conclusion

These data suggest that intracellular uptake of tenofovir and emtricitabine within the female genital tract varies by cell type and in the presence of hormonal contraceptives. The potential clinical implications of these findings should be further evaluated in vivo.

Determinants of individual variation in intracellular accumulation of anti-HIV nucleoside analog metabolites

Individual variation in response to antiretroviral therapy is well-known, but it is not clear if demographic characteristics such as gender, age, and ethnicity are responsible for the variation. To optimize anti-HIV therapy and guide antiretroviral drug discovery, determinants that cause variable responses to therapy need to be evaluated. We investigated the determinants of intracellular concentrations of nucleoside analogs using peripheral blood mononuclear cells from 40 healthy donors. We observed individual differences in the concentrations of the intracellular nucleoside analogs; the mean concentrations of the triphosphate metabolite of ethynylstavudine (4'-Ed4T), zidovudine (AZT), and lamivudine (3TC) were 0.71 pmol/10(6) cells (minimum and maximum, 0.10 and 3.00 pmol/10(6) cells, respectively), 0.88 pmol/10(6) cells (minimum and maximum, 0.10 and 15.18 pmol/10(6) cells, respectively), and 1.70 pmol/10(6) cells (minimum and maximum, 0.20 and 7.73 pmol/10(6) cells, respectively). Gender and ethnicity had no effect on the concentration of 4'-Ed4T and 3TC metabolites. There was a trend for moderation of the concentrations of AZT metabolites by gender (P = 0.17 for gender·metabolite concentration). We observed variability in the activity and expression of cellular kinases. There was no statistically significant correlation between thymidine kinase 1 (TK-1) activity or expression and thymidine analog metabolite concentrations. The correlation between the activity of deoxycytidine kinase (dCK) and the 3TC monophosphate metabolite concentration showed a trend toward significance (P = 0.1). We observed an inverse correlation between the multidrug-resistant protein 2 (MRP2) expression index and the concentrations of AZT monophosphate, AZT triphosphate, and total AZT metabolites. Our findings suggest that the observed variation in clinical response to nucleoside analogs may be due partly to the individual differences in the intracellular concentrations, which in turn may be affected by the cellular kinases involved in the phosphorylation pathway and ATP-binding cassette (ABC) transport proteins.

Zidovudine and Lamivudine for HIV Infection

Zidovudine and lamivudine (ZDV and 3TC) are long-standing nucleoside analog-reverse transcriptase inhibitors (NRTIs) with extensive clinical experience in a wide spectrum of patients from in utero through childhood and adult ages. The safety profiles of both drugs are well-known and side effects for ZDV most commonly include nausea/vomiting, fatigue, anemia/neutopenia, and lipoatrophy; while 3TC is well-tolerated. ZDV-3TC is currently a viable alternative NRTI backbone for initial three-drug therapy of HIV infection when tenofovir disoproxil fumarate-emtricitabine (TDF-FTC) cannot be used because of a relative or absolute contraindication. ZDV-3TC continue to be viable alternatives for children, pregnant women and in resource limited settings where other recommended options are not readily available. ZDV-3TC penetrate the Central Nervous System (CNS) well, which makes ZDV-3TC attractive for use in patients with HIV-associated neurological deficits. Additional benefits of these drugs may include the use of ZDV in combination with certain NRTIs to exert selective pressure to prevent particular drug resistance mutations from developing, and giving a short course of ZDV-3TC to prevent resistance after prophylactic single dose nevirapine.