Bidirectional Transfer of Raltegravir in an Ex Vivo Human Cotyledon Perfusion Model

Antiretroviral Regimen and Pregnancy Outcomes of Women Living with HIV in a US Cohort

Women who are pregnant and living with HIV have traditionally been excluded from clinical trials regarding new pharmacotherapy. Immediate initiation of antiretroviral therapy (ART) is recommended for women who are pregnant and living with HIV. Integrase inhibitors (INSTIs) are first-line recommended agents as they lead to more rapid HIV viral load reduction. We conducted a retrospective study of women who are pregnant and living with HIV who received prenatal care at the University of Washington. Mothers were categorized by ART class: INSTI, protease inhibitors (PI), and non-nucleoside reverse transcriptase inhibitors (NNRTI). Chi-square and t-tests were used for the analysis of baseline characteristics, and generalized estimating equations were used to adjust for HIV viral suppression between groups. There were a total of 234 mother-infant pairs whose pregnancies progressed beyond 20 weeks. The study demonstrated that women on INSTI regimens were more likely to have a shorter time to viral load suppression than women on NNRTI regimens. Additionally, seven congenital anomalies were identified in this cohort, none of which were neural tube defects. There was no perinatal transmission of HIV to any of the infants. This small cohort of women provides high-quality data regarding the safety and efficacy of INSTI use for both mothers and infants in resource-rich settings.

HIV-1 Integrase Strand Transfer Inhibitors and Neurodevelopment

Children born to mothers, with or at risk, of human immunodeficiency virus type-1 (HIV-1) infection are on the rise due to affordable access of antiretroviral therapy (ART) to pregnant women or those of childbearing age. Each year, up to 1.3 million HIV-1-infected women on ART have given birth with recorded mother-to-child HIV-1 transmission rates of less than 1%. Despite this benefit, the outcomes of children exposed to antiretroviral drugs during pregnancy, especially pre- and post- natal neurodevelopment remain incompletely understood. This is due, in part, to the fact that pregnant women are underrepresented in clinical trials. This is underscored by any potential risks of neural tube defects (NTDs) linked, in measure, to periconceptional usage of dolutegravir (DTG). A potential association between DTG and NTDs was first described in Botswana in 2018. Incidence studies of neurodevelopmental outcomes associated with DTG, and other integrase strand transfer inhibitors (INSTIs) are limited as widespread use of INSTIs has begun only recently in pregnant women. Therefore, any associations between INSTI use during pregnancy, and neurodevelopmental abnormalities remain to be explored. Herein, United States Food and Drug Administration approved ARVs and their use during pregnancy are discussed. We provide updates on INSTI pharmacokinetics and adverse events during pregnancy together with underlying mechanisms which could affect fetal neurodevelopment. Overall, this review seeks to educate both clinical and basic scientists on potential consequences of INSTIs on fetal outcomes as a foundation for future scientific investigations.

Ensemble learning for predicting ex vivo human placental barrier permeability

Background

The placental barrier protects the fetus from exposure to some toxicants and is vital for drug development and risk assessment of environmental chemicals. However, in vivo experiments for assessing the placental barrier permeability of chemicals is not ethically acceptable. Although ex vivo placental perfusion methods provide good alternatives for the assessment of placental barrier permeability, the application to a large number of test chemicals could be time- and resource-consuming. Computational prediction models for ex vivo placental barrier permeability are therefore desirable.

Methods

A total of 87 chemicals and corresponding 1444 physicochemical properties were divided into training and test datasets. Three types of algorithms including linear regression, random forest, and ensemble models were applied to develop prediction models for ex vivo placental barrier permeability.

Results

Among the tested models, the ensemble model integrating the previous two methods performed best for predicting ex vivo human placental barrier permeability with correlation coefficients of 0.887 and 0.825 when considering the applicability domain. An additional test on seven newly curated chemicals from the literature showed a good correlation coefficient of 0.879 which was further improved to 0.921 by considering the variation of experiments.

Conclusion

In this study, the first valid predicting model for ex vivo human placental barrier permeability was developed following the OECD guideline. The model is expected to be useful for assessing the human placental barrier permeability and can be integrated with developmental toxicity prediction models for investigating the toxic effects of chemicals on the fetus.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12859-022-04937-y.

Placental transfer of doravirine, a recent HIV-1 NNRTI in the ex vivo human cotyledon perfusion model

BACKGROUND

The recent HIV-1 NNRTI doravirine is likely to be used in pregnant women despite the complete lack of data on safety and exposure in the fetus. The objective of this study was to determine its placental transfer.

METHODS

Maternal-to-fetal transfer was investigated using the open-circuit ex vivo dually perfused human cotyledon model. Doravirine was added to a maternal perfusate (theoretical doravirine concentration of 250 ng/mL) containing 2 g/L human albumin and 20 g/L antipyrine, a marker to validate the cotyledon's viability, and cotyledons were dually perfused for up to 90 min.

RESULTS

In five experiments, the median (IQR) doravirine concentrations in the maternal and fetal compartments were, respectively, 303 (178-420) and 40 (30-54) ng/mL, the fetal-to-maternal ratio was 16% (12%-18%) and the clearance index (in comparison with antipyrine transfer) was 48% (35%-64%). The median accumulation index in cotyledon tissue was 39% (range 10%-66%).

CONCLUSIONS

Doravirine both crosses and accumulates in the placenta. This may be useful as pre/post-exposure prophylaxis to reduce the risk of vertical HIV transmission but carries the potential for fetal toxicities. Further investigation is required to determine the safety and efficacy of this new antiretroviral agent in pregnancy.

Risk of birth defects and perinatal outcomes in HIV-infected women exposed to integrase strand inhibitors during pregnancy

OBJECTIVES

Following an alert on neural tube defects and dolutegravir, we sought to evaluate if the exposure integrase strand transfer inhibitors (INSTIs) at conception was associated with birth defects or other adverse pregnancy outcomes.

METHODS

In the prospective national French Perinatal Cohort (EPF), we studied birth defects and other perinatal outcomes by matching each pregnant woman exposed to INSTIs with a pregnant woman exposed to darunavir/ritonavir receiving the same backbone of nucleoside reverse transcriptase inhibitors and matched for other characteristics such as age, geographic origin, centre and year of delivery.

RESULTS

Among 808 women exposed to INSTIs during pregnancy (raltegravir = 703, dolutegravir = 57 and elvitegravir = 48), we reported a slightly higher rate of birth defects in infants exposed at conception to raltegravir (6.7%) vs. infants exposed to raltegravir later in pregnancy: 2.9% if initiated during pregnancy as first-line, and 2.5% as second-line treatment,  P =0.04. When compared with matched controls, raltegravir exposure at conception was not significantly associated with birth defects: 6.4 vs. 2.3%, P = 0.08. There was no cluster of birth defect type and no neural tube defects were observed. Other perinatal outcomes, such as preterm birth and stillbirths, did not differ significantly between raltegravir-exposed women and matched counterparts. No difference in any outcome was observed for elvitegravir/cobicistat or dolutegravir.

CONCLUSION

We found a nonsignificant trend for an association between exposure to raltegravir at conception and birth defects, which needs to be evaluated by larger prospective surveillance data, as these drugs are increasingly prescribed in women living with HIV.

Placental transfer of the integrase strand inhibitors cabotegravir and bictegravir in the ex-vivo human cotyledon perfusion model

: Data on placental transfer is lacking for the recent HIV integrase inhibitors, bictegravir and cabotegravir, although their future use in pregnancy is to be expected. The objective of this study was to determine their transplacental pharmacokinetics. Maternal-to-fetal transfer was investigated using the open-circuit ex-vivo dually perfused human cotyledon model. Cabotegravir or bictegravir was added to a maternal perfusate containing 2 g/l of human albumin and antipyrine, a marker to validate the cotyledon's viability, and cotyledons were dually perfused for up to 90 min. For cabotegravir, in five experiments, the median (IQR 25-75) concentrations in the maternal and in the fetal compartments were, respectively, 550 ng/ml (344-788) and 48 ng/ml (37-54), with a maternal-to-fetal ratio of 10% (5-16) and a clearance index (in comparison with antipyrine transfer) of 22% (19-28). The median cotyledon accumulation index was 10% (2-21). For bictegravir, in six experiments, the median (IQR 25-75) concentrations in the maternal and in the fetal compartments were, respectively, 1650 ng/ml (1455-1960) and 126 ng/ml (112-142), with a maternal-to-fetal ratio of 7% (6-9.5) and a clearance index (in comparison with antipyrine transfer) of 21% (17-29). The median cotyledon accumulation index was 4% (3-5). Placental transfer of cabotegravir and bictegravir were low. This may not only limit the potential for fetal toxicities but also be a limit to their usefulness at the time of labor and delivery to reduce the risk of vertical HIV transmission. The safety and efficacy of these new integrase inhibitors in pregnancy require more investigation.

Placental transfer of Letermovir & Maribavir in the ex vivo human cotyledon perfusion model. New perspectives for in utero treatment of congenital cytomegalovirus infection

Background

Congenital cytomegalovirus infection can lead to severe sequelae. When fetal infection is confirmed, we hypothesize that fetal treatment could improve the outcome. Maternal oral administration of an effective drug crossing the placenta could allow fetal treatment. Letermovir (LMV) and Maribavir (MBV) are new CMV antivirals, and potential candidates for fetal treatment.

Methods

The objective was to investigate the placental transfer of LMV and MBV in the ex vivo method of the human perfused cotyledon. Term placentas were perfused, in an open-circuit model, with LMV or MBV at concentrations in the range of clinical peak plasma concentrations. Concentrations were measured using ultraperformance liquid chromatography coupled with tandem mass spectrometry. Mean fetal transfer rate (FTR) (fetal (FC) /maternal concentration), clearance index (CLI), accumulation index (AI) (retention of each drug in the cotyledon tissue) were measured. Mean FC were compared with half maximal effective concentrations of the drugs (EC_50(LMV) and EC_50(MBV)).

Results

For LMV, the mean FC was (± standard deviation) 1.1 ± 0.2 mg/L, 1,000-fold above the EC_50(LMV). Mean FTR, CLI and AI were 9 ± 1%, 35 ± 6% and 4 ± 2% respectively. For MBV, the mean FC was 1.4 ± 0.2 mg/L, 28-fold above the EC_50(MBV). Mean FTR, CLI and AI were 10 ± 1%, 50 ± 7% and 2 ± 1% respectively.

Conclusions

Drugs’ concentrations in the fetal side should be in the range for in utero treatment of fetuses infected with CMV as the mean FC was superior to the EC₅₀ for both molecules.

Placental transfer and tissue accumulation of dolutegravir in the ex vivo human cotyledon perfusion model

OBJECTIVE

To determine the transplacental pharmacokinetics of the HIV integrase inhibitor dolutegravir.

STUDY DESIGN

Maternal-to-fetal transfer across the term human placenta was investigated with the ex-vivo dually perfused cotyledon model, in 5 closed-circuit, recirculating experiments. Dolutegravir was added to a maternal perfusate containing antipyrine, a marker to validate the cotyledon's viability, and 2 g/liter of human albumin.

RESULTS

After 3h of recirculating perfusion, the mean (± SD) DTG concentrations in the maternal and in the fetal compartments were respectively 2450 ± 286 ng/mL and 715 ± 369 ng/mL, with a fetal-to-maternal ratio of 34% ± 18% and a clearance index (in comparison with antipyrine transfer) of 79% ± 23%. The mean cotyledon accumulation index was 153% ± 25%.

CONCLUSION

Fetal transplacental exposure to dolutegravir was considerable as well as accumulation in placental tissue. Whether this may lead to risks for the exposed fetus requires more investigation.

Placental transfer of elvitegravir and cobicistat in an ex-vivo human cotyledon double perfusion model

OBJECTIVE

To determine the transplacental pharmacokinetics of the HIV integrase strand transfer inhibitor elvitegravir and of cobicistat, a cytochrome P450 inhibitor used as a pharmacoenhancer in antiretroviral therapy.

DESIGN AND METHODS

Maternal-to-fetal transfer across the term human placenta was investigated with the ex-vivo dually perfused cotyledon model, in seven open-circuit experiments and 10 closed-circuit (recirculating) experiments. Elvitegravir and cobicistat were added to a maternal perfusate containing 2 g/l of human serum albumin and antipyrine, as a marker to validate the cotyledon's viability. Elvitegravir and cobicistat concentrations were measured using ultraperformance liquid chromatography coupled with tandem mass spectrometry.

RESULTS

For elvitegravir, in open-circuit experiments the mean (±SD) fetal transfer rate (FTR) (fetal/maternal concentration at steady state from 30 to 90 min) was 19 ± 13% and the mean clearance index was 0.46 ± 0.21; in the closed-circuit model, after 3 h of perfusion the FTR was 20 ± 10% and the mean accumulation index was 12.28 ± 5.57. For cobicistat, in the open perfusions the FTR was 23 ± 13% and the mean clearance index was 0.63 ± 0.34; in the closed perfusions after 3 h the fetal-to-maternal ratio of cobicistat was 21 ± 11%. The mean accumulation index was 3.46 ± 2.19 CONCLUSION:: The two models concurred to show moderate placental transfer of elvitegravir and cobicistat across the placenta as well as elvitegravir accumulation in the placenta tissue. Whether this may lead to toxicities and modifications in fetal or placental metabolism requires clinical studies.