Pharmacokinetics of HIV-Integrase Inhibitors During Pregnancy: Mechanisms, Clinical Implications and Knowledge Gaps

Pharmacokinetic and toxicological considerations affecting antiretroviral drug dosing in pregnant women

INTRODUCTION

To prevent mother-to-child transmission (PMTCT) of the human immunodeficiency virus (HIV) during pregnancy, the appropriate dosing regimens of antiretroviral (ARV) drugs need to be determined. Reliable data about pharmacokinetic (PK) characteristics of ARVs from randomized clinical trials (RCTs) are lacking, and post-marketing observational studies may offer valuable, but sometimes insufficient data, especially in pregnant people living with HIV (PLWHIV). This review article is focused PK and toxicological considerations affecting ARV dosing in pregnant PLWHIV.

AREAS COVERED

In our search, we included studies focused on PKs of ARVs in pregnancy available on PubMed, abstracts from recent global conferences and data from modeling studies. There are no significant changes in PKs of nucleoside/nucleotide reverse transcriptase inhibitors and non-nucleoside reverse transcriptase inhibitors throughout pregnancy. In contrast, the PKs of PIs and INSTIs are more variable, especially in the second and third trimesters.

EXPERT OPINION

Pregnant women are left out of RCTs. To the greatest extent possible, future research should include pregnant persons in RCTs, including PK studies, strictly considering maternal and fetal safety. Alternative innovative approaches/models need to be developed to obtain reliable data about rational pharmacotherapy of ARVs in the effective PMTCT of HIV, with maximum safety.

Physiologically-based pharmacokinetic models to predict drug exposure during pregnancy

As pregnant women are constantly exposed to drugs during pregnancy, either to treat long-term conditions or acute illnesses, drug safety is a major concern for the fetus and the mother. Clinical trials are rarely made in this population due to strict regulation and ethical reasons. However, drug pharmacokinetic (PK) parameters vary during pregnancy with an increase in distribution volume, renal clearance and more. In addition, the fetal distribution should be evaluated with the importance of placental diffusion, both active and passive. Therefore, there is a recent interest in the use of physiologically-based pharmacokinetic (PBPK) modeling to characterize these changes and complete the sparse data available on drug PK during pregnancy. Indeed, PBPK models integrate drug physicochemical and physiological parameters corresponding to each compartment of the body to estimate drug concentrations. This review establishes an overview on the current use of PBPK models in drug dosage determination for the pregnant woman, fetal exposure and drug interactions in the fetal compartment.

Exploring Lead-Like Molecules of Traditional Chinese Medicine for Treatment Quest against Aliarcobacter butzleri: In Silico Toxicity Assessment, Dynamics Simulation, and Pharmacokinetic Profiling

Background

Aliarcobacter butzleri is a Gram-negative, curved or spiral-shaped, microaerophilic bacterium and causes human infections, specifically diarrhea, fever, and sepsis. The research objective of this study was to employ computer-aided drug design techniques to identify potential natural product inhibitors of a vital enzyme in this bacterium. The pyrimidine biosynthesis pathway in its core genome fraction is crucial for its survival and presents a potential target for novel therapeutics. Hence, novel small molecule inhibitors were identified (from traditional Chinese medicinal (TCM) compound library) against it, which may be used for possible curbing of infection by A. butzleri. Methods. A comprehensive subtractive genomics approach was utilized to identify a key enzyme (orotidine-5'-phosphate decarboxylase) cluster conserved in the core genome fraction of A. butzleri. It was selected for inhibitor screening due to its vital role in pyrimidine biosynthesis. TCM library (n > 36,000 compounds) was screened against it using pharmacophore model based on orotidylic acid (control), and the obtained lead-like molecules were subjected to structural docking using AutoDock Vina. The top-scoring compounds, ZINC70454134, ZINC85632684, and ZINC85632721, underwent further scrutiny via a combination of physiological-based pharmacokinetics, toxicity assessment, and atomic-scale dynamics simulations (100 ns).

Results

Among the screened compounds, ZINC70454134 displayed the most favorable characteristics in terms of binding, stability, absorption, and safety parameters. Overall, traditional Chinese medicine (TCM) compounds exhibited high bioavailability, but in diseased states (cirrhosis, renal impairment, and steatosis), there was a significant decrease in absorption, Cmax, and AUC of the compounds compared to the healthy state. Furthermore, MD simulation demonstrated that the ODCase-ZINC70454134 complex had a superior overall binding affinity, supported by PCA proportion of variance and eigenvalue rank analysis. These favorable characteristics underscore its potential as a promising drug candidate.

Conclusion

The computer-aided drug design approach employed for this study helped expedite the discovery of antibacterial compounds against A. butzleri, offering a cost-effective and efficient approach to address infection by it. It is recommended that ZINC70454134 should be considered for further experimental analysis due to its indication as a potential therapeutic agent for combating A. butzleri infections. This study provides valuable insights into the molecular basis of biophysical inhibition of A. butzleri through TCM compounds.

Antiretroviral Therapy in Pregnancy: A 2023 Review of the Literature

PURPOSE OF REVIEW

Selection of antiretroviral therapy during pregnancy must consider maternal physiology and resulting pharmacokinetic changes in pregnancy, resistance and efficacy profiles, tolerability and frequency of adverse effects, teratogenicity, and maternal, neonatal, and pregnancy outcomes. The objective of this review is to summarize the underlying data that informs the current clinical perinatal guidelines in the USA.

RECENT FINDINGS

Data now supports the use of dolutegravir at all stages of pregnancy with no significant increase in neural tube defects. Safety and pharmacokinetic data on newer antiretroviral medications in pregnancy continue to lag behind the general population. While there are multiple safety and tolerability concerns with older regimens, there are now multiple options of regimens that are highly efficacious and have good safety data in pregnancy. Most pregnant patients who are virally suppressed on a well-tolerated regimen are able to safely continue those medications during pregnancy.

Long-acting dolutegravir formulations prevent neurodevelopmental impairments in a mouse model

The World Health Organization has recommended dolutegravir (DTG) as a preferred first-line treatment for treatment naive and experienced people living with human immunodeficiency virus type one (PLWHIV). Based on these recommendations 15 million PLWHIV worldwide are expected to be treated with DTG regimens on or before 2025. This includes pregnant women. Current widespread use of DTG is linked to the drug's high potency, barrier to resistance, and cost-effectiveness. Despite such benefits, potential risks of DTG-linked fetal neurodevelopmental toxicity remain a concern. To this end, novel formulation strategies are urgently needed in order to maximize DTG's therapeutic potentials while limiting adverse events. In regard to potential maternal fetal toxicities, we hypothesized that injectable long-acting nanoformulated DTG (NDTG) could provide improved safety by reducing drug fetal exposures compared to orally administered native drug. To test this notion, we treated pregnant C3H/HeJ mice with daily oral native DTG at a human equivalent dosage (5 mg/kg; n = 6) or vehicle (control; n = 8). These were compared against pregnant mice injected with intramuscular (IM) NDTG formulations given at 45 (n = 3) or 25 (n = 4) mg/kg at one or two doses, respectively. Treatment began at gestation day (GD) 0.5. Magnetic resonance imaging scanning of live dams at GD 17.5 was performed to obtain T1 maps of the embryo brain to assess T1 relaxation times of drug-induced oxidative stress. Significantly lower T1 values were noted in daily oral native DTG-treated mice, whereas comparative T1 values were noted between control and NDTG-treated mice. This data reflected prevention of DTG-induced oxidative stress when delivered as NDTG. Proteomic profiling of embryo brain tissues harvested at GD 17.5 demonstrated reductions in oxidative stress, mitochondrial impairments, and amelioration of impaired neurogenesis and synaptogenesis in NDTG-treated mice. Pharmacokinetic (PK) tests determined that both daily oral native DTG and parenteral NDTG achieved clinically equivalent therapeutic plasma DTG levels in dams (4,000-6,500 ng/mL). Importantly, NDTG led to five-fold lower DTG concentrations in embryo brain tissues compared to daily oral administration. Altogether, our preliminary work suggests that long-acting drug delivery can limit DTG-linked neurodevelopmental deficits.

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.

Effect of Integrase Strand Transfer Inhibitor Use on Time to HIV Viral Suppression before Delivery

OBJECTIVES

We sought to determine whether pregnant individuals with human immunodeficiency virus (HIV) prescribed integrase strand transfer inhibitor (INSTI) antiretrovirals (ARVs) achieve viral suppression faster than individuals taking non-INSTI regimens and to determine whether there were differences in viral suppression at delivery among INSTI ARVs.

METHODS

This is a retrospective cohort study of pregnant individuals with HIV who delivered a live infant during the study period (January 1, 2009-December 31, 2020). Patients' ARV therapy (ART) was classified as including INSTI or non-INSTI. We compared the proportion of individuals with viral suppression at delivery by group and individual INSTI ARVs using χ2 and Fisher exact tests. A log rank test was used to compare time to viral suppression on ARVs.

RESULTS

During the study period, 168 individuals delivered a live infant. Most of the patients were diagnosed as having HIV before pregnancy and had taken ARVs before conception (76%), but fewer than half had an undetectable viral load at the first antenatal visit (45%). During pregnancy, 46% were prescribed INSTI and 54% were prescribed non-INSTI ARVs. Most had an undetectable HIV RNA viral load at delivery (75% INSTI and 72% non-INSTI, P = 0.7). The time to viral suppression was similar between groups (log rank test P = 0.43). Viral suppression at delivery was similar among INSTI ARVs: raltegravir (53%), elvitegravir (88%), dolutegravir (73%), and bictegravir (88%) (P = 0.13).

CONCLUSIONS

Despite recommendations to prescribe INSTI in pregnancy for rapid viral suppression, we did not find a significant difference in time to viral suppression when pregnant individuals were taking non-INSTI ARVs. We did not find that one INSTI ARV was superior for viral suppression.

Efficacy and Safety of Bictegravir-Based Regimen in Pregnant Women Living with HIV: A Case Report

Bictegravir (BIC) is included in international guidelines as the first line of therapy for patients living with Human Immunodeficiency Virus (HIV), either as initial therapy or as a replacement for patients with prior antiretroviral therapy (ART). Due to limited efficacy and safety data, BIC is currently not recommended during pregnancy. Data on the safety and efficacy of BIC during pregnancy were unavailable at the time of drug approval. In our case, BIC/TAF/FTC was effective in suppressing viral load (VL) in pregnancy, and there were no reported safety issues for the mother or the baby.

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.

A Pharmacokinetic Dose-Optimization Study of Cabotegravir and Bictegravir in a Mouse Pregnancy Model

Animal pregnancy models can be useful tools to study HIV antiretroviral safety and toxicity and to perform mechanistic studies that are not easily performed in humans. Utilization of clinically relevant dosing in these models improves the relevance of the findings. Cabotegravir and bictegravir are new integrase strand transfer inhibitors (INSTIs), recently approved for the treatment of people living with HIV. Studies of these drugs in pregnancy are very limited. The objective of this study was to perform a dose-optimization study of cabotegravir and bictegravir in a mouse pregnancy model with the goal of determining the dose that would yield plasma drug concentrations similar those observed in humans. Pregnant mice were administered increasing doses of cabotegravir or bictegravir in combination with emtricitabine and tenofovir by oral gavage from gestational day 11.5 to 15.5. Drug concentrations in the maternal plasma at 1 h and 24 h post drug administration and in the amniotic fluid at 1 h post drug administration were determined using high-performance liquid chromatography coupled with tandem mass spectrometry. A review of cabotegravir and bictegravir human pharmacokinetic studies are also reported. We hope these data will encourage studies of HIV antiretroviral safety/toxicity and mechanistic studies in animal pregnancy models.

Comprehensive Review on Different Analytical Techniques for HIV 1- Integrase Inhibitors: Raltegravir, Dolutegravir, Elvitegravir and Bictegravir

The advent of HIV-Integrase inhibitors (IN) has marked a significant impact on the lives of HIV patients. Since the launch of the first anti retro-viral drug "Azidothymidine" to the recent advances of IN inhibitors, about 27.4 million people benefit by antiretroviral therapy (ART). The path had been challenging due to many crossroads, leading to the discovery of newer targets. One such recent ART target is Integrase. Use of Integrase inhibitors has surpassed the usage of all other ART owing to a strong barrier to resistance and have been reported to be the first-line therapy. Raltegravir, Elvitegravir, Dolutegravir and Bictegravir are US FDA approved IN inhibitors. The high usage of ART created an opportunity to study various analytical techniques for IN inhibitors. Hitherto, no review encompassing all IN inhibitors is presented. Herein, this review describes the analytical techniques employed for IN inhibitors estimation and quantification reported in the literature and official compendia. Literature suggests that most studies focus on LC-MS/MS and HPLC methods for drug estimation, and few reports suggest spectrophotometric, spectrofluorimetric and electrochemical methods. Furthermore, the review presents the techniques that describe the quantification of integrase drugs in various matrices. Although, antiretroviral drugs are extensively used but data suggests that limited studies have been conducted for determination of impurity profile and stability. This therefore, presents a scope to detect and validate impurities in order to meet ICH guidelines for their limits and further to improve the quality and safety of antiretroviral drugs.

Cabotegravir, the Long-Acting Integrase Strand Transfer Inhibitor, Potently Inhibits Human T-Cell Lymphotropic Virus Type 1 Transmission in vitro

Human T-cell lymphotropic virus type 1 (HTLV-1) is a deltaretrovirus most prevalent in southwestern Japan, sub-Saharan Africa, Australia, South America, and the Caribbean. Latest figures approximate 10 million people worldwide to be infected with HTLV-1. This is likely a significant underestimation due to lack of screening in endemic areas and absence of seroconversion symptoms. The two primary diseases associated with HTLV-1 infection are adult T cell leukaemia-lymphoma, a malignant and, sometimes, aggressive cancer; and HTLV-1 associated myelopathy/tropical spastic paraparesis, a debilitating neurological degenerative disease. Unfortunately, despite the poor prognosis, there is currently no effective treatment for HTLV-1 infection. We previously showed that integrase strand transfer inhibitors (INSTIs) clinically used for human immunodeficiency virus type 1 (HIV-1) prophylaxis and treatment are also effective against HTLV-1 transmission in vitro. In 2021 a new INSTI, cabotegravir, was approved by the FDA for HIV-1 treatment. We thus set out to evaluate its efficacy against HTLV-1 infection in vitro. Strand transfer assays performed using recombinant HTLV-1 integrase treated with increasing concentrations of cabotegravir, effectively inhibited strand transfer activity, displaying an IC50 of 77.8 ± 22.4 nM. Furthermore, cabotegravir blocked HTLV-1 transmission in tissue culture; we determined an EC50 of 0.56 ± 0.26 nM, similar to bictegravir. Alu-PCR confirmed the block in integration. Thus, there are four INSTIs and one reverse transcriptase inhibitor approved by the FDA for HIV-1 treatment, that potently block HTLV-1 infection in vitro. This should strongly encourage the establishment of a new standard of HTLV-1 treatment - particularly for pre-exposure prophylaxis and prevention of mother-to-child transmission.

Pharmacokinetics and placental transfer of dolutegravir in pregnancy

Dolutegravir is currently recommended by the WHO as the preferred first-line treatment for all people with HIV, including pregnant women. Estimates indicate that, by 2024, nearly 22 million adults in low- and middle-income countries will have transitioned to dolutegravir-based ART. It is therefore critical that there is a clear appreciation and understanding of the risks that may be associated with in utero exposure to dolutegravir. In this review we consolidate data from studies on dolutegravir and the placenta. The studies have largely focused on the pharmacokinetics and placental transfer of dolutegravir in pregnancy. These include studies on transplacental transfer of dolutegravir, ex vivo placenta perfusion models, physiologically based pharmacokinetic (PBPK) models and animal studies. The data available clearly demonstrate that placental transfer of dolutegravir occurs in moderate to high concentrations. Intracellular placental dolutegravir has been demonstrated in the placental villous tissue. There are limited data suggesting that pregnancy is associated with decreased maternal dolutegravir levels. In addition, PBPK models have great potential in predicting the passage of drugs through the placenta and further contributing towards the elucidation of fetal exposure. The animal studies available demonstrate that in utero dolutegravir exposure can be associated with neural tube defects. Taking into consideration that antiretroviral exposure may be associated with poor placental development or function and increased risk of adverse effects to the fetus, it is crucially important that these risks are evaluated, especially with the rapid scale up of dolutegravir-based ART into national treatment programmes.

Comparative Clinical Pharmacokinetics and Pharmacodynamics of HIV-1 Integrase Strand Transfer Inhibitors: An Updated Review

Bictegravir, cabotegravir, dolutegravir, elvitegravir, and raltegravir are members of the latest class of antiretrovirals available to treat human immunodeficiency virus (HIV) infection, the integrase strand transfer inhibitors. Integrase strand transfer inhibitors are potent inhibitors of the HIV integrase enzyme with IC_90/95 values in the low nanogram per milliliter range and they retain antiviral activity against strains of HIV with acquired resistance to other classes of antiretrovirals. Each of the integrase strand transfer inhibitors have unique pharmacokinetic/pharmacodynamic properties, influencing their role in clinical use in specific subsets of patients. Cabotegravir, approved for use in Canada but not yet by the US Food and Drug Administration, is formulated in both oral and intramuscular formulations; the latter of which has shown efficacy as a long-acting extended-release formulation. Cabotegravir, raltegravir, and dolutegravir have minimal drug-drug interaction profiles, as their metabolism has minimal cytochrome P450 involvement. Conversely, elvitegravir metabolism occurs primarily via cytochrome P450 3A4 and requires pharmacokinetic boosting to achieve systemic exposures amenable to once-daily dosing. Bictegravir metabolism has similar contributions from both cytochrome P450 3A4 and uridine 5'-diphospho-glucuronosyltransferase 1A1. Bictegravir, dolutegravir, and raltegravir are recommended components of initial regimens for most people with HIV in the US adult and adolescent HIV treatment guidelines. This review summarizes and compares the pharmacokinetics and pharmacodynamics of the integrase strand transfer inhibitor agents, and describes specific pharmacokinetic considerations for persons with hepatic impairment, renal dysfunction, pregnancy, and co-infections.

The Use of Integrase Strand Transfer Inhibitors to Treat HIV in Pregnancy

For pregnant women with HIV, antiretroviral therapy (ART) plays a key role in prevention of perinatal transmission. Newer antiretroviral regimens now contain integrase strand transfer inhibitors, which have been found to rapidly suppress HIV viral load in nonpregnant women; however, there are limited data for use in pregnancy. Here, we present the case of a pregnant woman with well-controlled HIV on a well-tolerated prepregnancy regimen of bictegravir, emtricitabine, and tenofovir alafenamide. As there are limited safety data on bictegravir in pregnancy, this ART regimen was changed to a preferred regimen for pregnancy. In the second trimester, because of adverse effects from the new ART regimen and after a risk-benefit discussion, the patient restarted the original regimen. She was able to maintain viral suppression until giving birth.

Structural basis for the inhibition of HTLV-1 integration inferred from cryo-EM deltaretroviral intasome structures

Between 10 and 20 million people worldwide are infected with the human T-cell lymphotropic virus type 1 (HTLV-1). Despite causing life-threatening pathologies there is no therapeutic regimen for this deltaretrovirus. Here, we screened a library of integrase strand transfer inhibitor (INSTI) candidates built around several chemical scaffolds to determine their effectiveness in limiting HTLV-1 infection. Naphthyridines with substituents in position 6 emerged as the most potent compounds against HTLV-1, with XZ450 having highest efficacy in vitro. Using single-particle cryo-electron microscopy we visualised XZ450 as well as the clinical HIV-1 INSTIs raltegravir and bictegravir bound to the active site of the deltaretroviral intasome. The structures reveal subtle differences in the coordination environment of the Mg2+ ion pair involved in the interaction with the INSTIs. Our results elucidate the binding of INSTIs to the HTLV-1 intasome and support their use for pre-exposure prophylaxis and possibly future treatment of HTLV-1 infection.

Dolutegravir Inhibition of Matrix Metalloproteinases Affects Mouse Neurodevelopment

Dolutegravir (DTG) is a first-line antiretroviral drug (ARV) used in combination therapy for the treatment of human immunodeficiency virus type-1 (HIV-1) infection. The drug is effective, safe, and well tolerated. Nonetheless, concerns have recently emerged for its usage in pregnant women or those of child-bearing age. Notably, DTG-based ARV regimens have been linked to birth defects seen as a consequence of periconceptional usages. To this end, uncovering an underlying mechanism for DTG-associated adverse fetal development outcomes has gained clinical and basic research interest. We now report that DTG inhibits matrix metalloproteinases (MMPs) activities that could affect fetal neurodevelopment. DTG is a broad-spectrum MMPs inhibitor and binds to Zn⁺⁺ at the enzyme’s catalytic domain. Studies performed in pregnant mice show that DTG readily reaches the fetal central nervous system during gestation and inhibits MMP activity. Postnatal screenings of brain health in mice pups identified neuroinflammation and neuronal impairment. These abnormalities persist as a consequence of in utero DTG exposure. We conclude that DTG inhibition of MMPs activities during gestation has the potential to affect prenatal and postnatal neurodevelopment.

HIV in pregnancy: Mother-to-child transmission, pharmacotherapy, and toxicity

An estimated 1.3 million pregnant women were living with HIV in 2018. HIV infection is associated with adverse pregnancy outcomes and all HIV-positive pregnant women, regardless of their clinical stage, should receive a combination of antiretroviral drugs to suppress maternal viral load and prevent vertical fetal infection. Although antiretroviral treatment in pregnant women has undoubtedly minimized mother-to-child transmission of HIV, several uncertainties remain. For example, while pregnancy is accompanied by changes in pharmacokinetic parameters, relevant data from clinical studies are lacking. Similarly, long-term adverse effects of exposure to antiretrovirals on fetuses have not been studied in detail. Here, we review current knowledge on HIV effects on the placenta and developing fetus, recommended antiretroviral regimens, and pharmacokinetic considerations with particular focus on placental transport. We also discuss recent advances in antiretroviral research and potential effects of antiretroviral treatment on placental/fetal development and programming.

Therapeutic Drug Monitoring of HIV Antiretroviral Drugs in Pregnancy: A Narrative Review

To date, therapeutic drug monitoring (TDM) has played an important role in the management of pregnant HIV patients on highly active antiretroviral therapy. Historically, in pregnant women living with HIV, the third agent in triple therapy has been either non-nucleoside reverse transcriptase inhibitors or protease inhibitors (PIs). PIs have been the preferred agents because of their robustness from the perspective of viral resistance and the dominant drug class for the management of HIV during pregnancy for the previous decade. As with many drugs used during pregnancy, pharmacokinetic changes decrease exposure to these agents as the pregnancy progresses. This can lead to viral escape at the time of pregnancy and ultimately increase the risk of mother-to-child transmission (MTCT) of HIV. TDM has been well-established for this class of highly active antiretroviral therapy, and appropriate dose adjustment studies have been performed. At present, there is a shift from the traditional treatment paradigm in pregnancy to a new drug class, integrase strand transfer inhibitors (INSTIs). Although INSTIs are affected by pharmacokinetic changes during pregnancy, they do not harbor the same issues with viral escape as seen with PIs at birth and in general eliminate the need for boosting with additional agents like ritonavir (r) and cobicistat (c) [bar elvitegravir (EVG)] that can lead to interactions with treatment of other common infections in HIV, including tuberculosis. Furthermore, INSTIs are the most successful medication for rapidly reducing the viral load (VL) in HIV patients, a useful factor where VL may be unknown, or in late presenters. These merits make INSTIs the best choice in pregnancy, although their use has been hindered in recent years by a report of neural tube defects from a large African study with dolutegravir (DTG). New data from Botswana and Brazil indicate that this risk is less significant than previously reported, necessitating further data to shed light on this critical issue. Current international guidelines including DHHS, EACS, WHO, and BHIVA (for patients with VLs >100,000 copies/mL or late presenters) now recommend INSTIs as first-line agents. The role of TDM in INSTIs shifts to cases of insufficient viral suppression with standard adherence measures, cases of drug-drug interactions, or cases where EVG/c is continued throughout pregnancy, and thus remains an important aspect of HIV care in pregnancy.

Characterization of Plasma Protein Alterations in Pregnant and Postpartum Individuals Living With HIV to Support Physiologically-Based Pharmacokinetic Model Development

Background: Alterations in plasma protein concentrations in pregnant and postpartum individuals can influence antiretroviral (ARV) pharmacokinetics. Physiologically-based pharmacokinetic (PBPK) models can serve to inform drug dosing decisions in understudied populations. However, development of such models requires quantitative physiological information (e.g., changes in plasma protein concentration) from the population of interest. Objective: To quantitatively describe the time-course of albumin and α1-acid glycoprotein (AAG) concentrations in pregnant and postpartum women living with HIV. Methods: Serum and plasma protein concentrations procured from the International Maternal Pediatric Adolescent AIDS Clinical Trial Protocol 1026s (P1026s) were analyzed using a generalized additive modeling approach. Separate non-parametric smoothing splines were fit to albumin and AAG concentrations as functions of gestational age or postpartum duration. Results: The analysis included 871 and 757 serum albumin concentrations collected from 380 pregnant (~20 to 42 wks gestation) and 354 postpartum (0 to 46 wks postpartum) women, respectively. Thirty-six and 32 plasma AAG concentrations from 31 pregnant (~24 to 38 wks gestation) and 30 postpartum women (~2-13 wks postpartum), respectively, were available for analysis. Estimated mean albumin concentrations remained stable from 20 wks gestation to term (33.4 to 34.3 g/L); whereas, concentrations rapidly increased postpartum until stabilizing at ~42.3 g/L 15 wk after delivery. Estimated AAG concentrations slightly decreased from 24 wks gestation to term (53.6 and 44.9 mg/dL) while postpartum levels were elevated at two wks after delivery (126.1 mg/dL) and subsequently declined thereafter. Computational functions were developed to quantitatively communicate study results in a form that can be readily utilized for PBPK model development. Conclusion: By characterizing the trajectory of plasma protein concentrations in pregnant and postpartum women living with HIV, our analysis can increase confidence in PBPK model predictions for HIV antiretrovirals and better inform drug dosing decisions in this understudied population.

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.

An evaluation of cabotegravir for HIV treatment and prevention

Introduction: Oral pre-exposure prophylaxis (PrEP) and antiretroviral therapy (ART) represent the cornerstones of HIV infection prevention and treatment. However, despite their high efficacy, the need to take daily oral pill(s) negatively impacts long-term patient adherence. In some cases, it can also be associated with drug-drug interactions and adverse gastrointestinal effects, as well as being a constant reminder to individuals of their HIV status. The availability of long-acting non-orally administered antiretroviral drugs could, therefore, be extremely useful. Cabotegravir (CAB) is a second-generation integrase strand transfer inhibitor, characterized by a relatively high genetic barrier and good antiretroviral potency, which is administrable as a long-acting injectable suspension (LAI CAB).Areas covered: The authors present and discuss the efficacy and available safety data of LAI CAB, either when co-administered with rilpivirine (RPV; LAI CAB + RPV) for the treatment of HIV infection, or when used as single agent for PrEP.Expert opinion: Cabotegravir has the potential to play a primary role in the treatment and prevention of HIV infection. The future availability of LAI CAB + RPV and LAI CAB may mark the beginning of an era of LAI ART and PrEP, respectively.

HIV-1 Integrase Inhibitors: A Comparative Review of Efficacy and Safety

The newest class of antiretrovirals for all persons living with HIV are the integrase strand transfer inhibitors (INSTIs). Since 2007, five INSTIs have been introduced: raltegravir, elvitegravir, dolutegravir, bictegravir, and cabotegravir. The INSTIs have favorable pharmacokinetic and pharmacodynamic properties, which contribute to both their effectiveness and their ease of use. With the exception of cabotegravir, each INSTI is US Food and Drug Administration approved for treatment-naïve individuals initiating antiretroviral therapy. All of the INSTIs, except raltegravir, are approved for antiretroviral treatment simplification for virologically suppressed patients without INSTI resistance. Data also support the use of dolutegravir and raltegravir in individuals with antiretroviral resistance as part of an optimized antiretroviral regimen. INSTIs are generally well tolerated by people living with HIV compared with older classes of antiretrovirals, but emerging data suggest that some INSTIs contribute to weight gain. Due to their efficacy, safety, and ease of use, HIV treatment guidelines recommend oral INSTIs as preferred components of antiretroviral therapy for individuals initiating therapy. The newest INSTI, cabotegravir, represents an alternative to oral administration of life-long antiretroviral therapy with the availability of a long-acting injectable formulation. This review summarizes the current use of INSTIs in adults living with HIV, highlighting the similarities and differences within the class related to pharmacodynamics, pharmacokinetics, safety, dosing, and administration that contribute to their role in modern antiretroviral therapy.

Effect of Pregnancy on Unbound Raltegravir Concentrations in the ANRS 160 RalFe Trial

A population pharmacokinetic model was developed to explore the pharmacokinetics modification of unbound raltegravir during pregnancy. The RalFe ANRS160 study was a nonrandomized, open-label, multicenter trial enrolling HIV-infected pregnant women receiving a combined antiretroviral regimen containing 400 mg raltegravir twice daily. Biological samples were collected during the third trimester of pregnancy (between 30 and 37 weeks of gestational age) and at postpartum (4 to 6 weeks after delivery). A population pharmacokinetic model was developed with Monolix software. A total of 360 plasma samples were collected from 43 women during pregnancy and postpartum. The unbound raltegravir was described by a one-compartment model with a transit compartment with first-order absorption, evolving to bound raltegravir (by a linear binding to albumin) or metabolism to RAL-glucuronide or to a first-order elimination, with a circadian rhythm. During pregnancy, the absorption was decreased and delayed and the raltegravir elimination clearance and glucuronidation increased by 37%. Median total and unbound area under the curve from 0 to 12 h significantly decreased by 36% and 27% during pregnancy. Median total trough concentration (C _trough) decreased significantly in the evening (28%); however, the median total C _trough in the morning, unbound C _trough in the morning, and unbound C _trough in the evening showed a nonsignificant decrease of 16%, 1%, and 15%, respectively, during pregnancy compared to the postpartum period. This is the first study reporting the pharmacokinetics of unbound raltegravir during pregnancy. As unbound C _trough did not significantly decrease during the third trimester, the pregnancy effect on raltegravir unbound concentrations was not considered clinically relevant. (This study has been registered at ClinicalTrials.gov under identifier NCT02099474.).

Pharmacokinetics of HIV therapies in pregnant patients: an update

INTRODUCTION

Mother-to-child transmission (MTCT) of HIV is thought to account for over 90% of new pediatric infections, and is associated with poor maternal and fetal outcomes. As such ensuring further reduction in MTCT is a priority in HIV treatment and prevention programs.

AREAS COVERED

This review aims to provide a comprehensive update on the pharmacokinetics of recently approved antiretroviral drugs and novel drug formulations and delivery systems. Alongside recent recommendations for dose adjustments, and an overview of the implications of co-infections on the pharmacokinetics of antiretrovirals relevant to pregnant HIV positive patients. Additionally, potential opportunities to progress pharmacokinetic research of new treatments in this population are highlighted.

EXPERT OPINION

In order to improve our understanding of how to provide safe and effective treatment to HIV positive pregnant women, further work is required to enable their inclusion in early stages of clinical trials. Incentives must be created for this research, in the form of additional investment by key stakeholders and regulatory agencies. Furthermore, as the incidence of MTCT is reduced globally there is a need to conduct long-term pharmacovigilance studies in uninfected children exposed to HIV and antiretrovirals in utero, in order to determine the safest and most effective antiretroviral therapies.

Pharmacokinetic studies in pregnancy

The effects of the many biochemical and physiologic changes of pregnancy on the dose-response relationship of drugs administered to pregnant women are poorly understood. The dose-response relationship is affected by pharmacokinetics, or what the body does to a drug, and pharmacodynamics, or what a drug does to the body. Insights into the potential effects of the changes of pregnancy on one aspect of the dose-response relationship of a drug can be obtained by studying the pharmacokinetics of the drug in the various stages of pregnancy and the postpartum period. There are several available approaches to studying pharmacokinetic changes in pregnancy. Single trough screening studies can provide qualitative estimates of elimination clearance, which with the dosing rate determines the steady-state drug concentration, throughout pregnancy and into the postpartum period. Population pharmacokinetic studies such as two stage pharmacokinetic studies and studies using a nonlinear mixed effects pharmacokinetic modeling approach can characterize pharmacokinetic changes more rigorously.

Pharmacokinetics, Placental and Breast Milk Transfer of Antiretroviral Drugs in Pregnant and Lactating Women Living with HIV

BACKGROUND

Remarkable progress has been achieved in the identification of HIV infection in pregnant women and in the prevention of vertical HIV transmission through maternal antiretroviral treatment (ART) and neonatal antiretroviral drug (ARV) prophylaxis in the last two decades. Millions of women globally are receiving combination ART throughout pregnancy and breastfeeding, periods associated with significant biological and physiological changes affecting the pharmacokinetics (PK) and pharmacodynamics (PD) of ARVs. The objective of this review was to summarize currently available knowledge on the PK of ARVs during pregnancy and transport of maternal ARVs through the placenta and into the breast milk. We also summarized main safety considerations for in utero and breast milk ARVs exposures in infants.

METHODS

We conducted a review of the pharmacological profiles of ARVs in pregnancy and during breastfeeding obtained from published clinical studies. Selected maternal PK studies used a relatively rich sampling approach at each ante- and postnatal sampling time point. For placental and breast milk transport of ARVs, we selected the studies that provided ratios of maternal to the cord (M:C) plasma and breast milk to maternal plasma (M:P) concentrations, respectively.

RESULTS

We provide an overview of the physiological changes during pregnancy and their effect on the PK parameters of ARVs by drug class in pregnancy, which were gathered from 45 published studies. The PK changes during pregnancy affect the dosing of several protease inhibitors during pregnancy and limit the use of several ARVs, including three single tablet regimens with integrase inhibitors or protease inhibitors co-formulated with cobicistat due to suboptimal exposures. We further analysed the currently available data on the mechanism of the transport of ARVs from maternal plasma across the placenta and into the breast milk and summarized the effect of pregnancy on placental and of breastfeeding on mammal gland drug transporters, as well as physicochemical properties, C:M and M:P ratios of individual ARVs by drug class. Finally, we discussed the major safety issues of fetal and infant exposure to maternal ARVs.

CONCLUSIONS

Available pharmacological data provide evidence that physiological changes during pregnancy affect maternal, and consequently, fetal ARV exposure. Limited available data suggest that the expression of drug transporters may vary throughout pregnancy and breastfeeding thereby possibly impacting the amount of ARV crossing the placenta and secreted into the breast milk. The drug transporter's role in the fetal/child exposure to maternal ARVs needs to be better understood. Our analysis underscores the need for more pharmacological studies with innovative study design, sparse PK sampling, improved study data reporting and PK modelling in pregnant and breastfeeding women living with HIV to optimize their treatment choices and maternal and child health outcomes.

Pregnancy Gestation Impacts on HIV-1-Specific Granzyme B Response and Central Memory CD4 T Cells

Pregnancy induces alterations in peripheral T-cell populations with both changes in subset frequencies and anti-viral responses found to alter with gestation. In HIV-1 positive women anti-HIV-1 responses are associated with transmission risk, however detailed investigation into both HIV-1-specific memory responses associated with HIV-1 control and T-cell subset changes during pregnancy have not been undertaken. In this study we aimed to define pregnancy and gestation related changes to HIV-1-specific responses and T-cell phenotype in ART treated HIV-1 positive pregnant women. Eleven non-pregnant and 24 pregnant HIV-1 positive women were recruited, peripheral blood samples taken, fresh cells isolated, and compared using ELISpot assays and flow cytometry analysis. Clinical data were collected as part of standard care, and non-parametric statistics used. Alterations in induced IFNγ, IL-2, IL-10, and granzyme B secretion by peripheral blood mononuclear cells in response to HIV-1 Gag and Nef peptide pools and changes in T-cell subsets between pregnant and non-pregnant women were assessed, with data correlated with participant clinical parameters and longitudinal analysis performed. Cross-sectional comparison identified decreased IL-10 Nef response in HIV-1 positive pregnant women compared to non-pregnant, while correlations exhibited reversed Gag and Nef cytokine and protease response associations between groups. Longitudinal analysis of pregnant participants demonstrated transient increases in Gag granzyme B response and in the central memory CD4 T-cell subset frequency during their second trimester, with a decrease in CD4 effector memory T cells from their second to third trimester. Gag and Nef HIV-1-specific responses diverge with pregnancy time-point, coinciding with relevant T-cell phenotype, and gestation associated immunological adaptations. Decreased IL-10 Nef and both increased granzyme B Gag response and central memory CD4 T cells implies that amplified antigen production is occurring, which suggests a period of compromised HIV-1 control in pregnancy.

Assessment of Maternal and Fetal Dolutegravir Exposure by Integrating Ex Vivo Placental Perfusion Data and Physiologically-Based Pharmacokinetic Modeling

Antiretroviral therapy during pregnancy reduces the risk of vertical HIV‐1 transmission. However, drug dosing is challenging as pharmacokinetics (PK) may be altered during pregnancy. We combined a pregnancy physiologically‐based pharmacokinetic (PBPK) modeling approach with data on placental drug transfer to simulate maternal and fetal exposure to dolutegravir (DTG). First, a PBPK model for DTG exposure in healthy volunteers was established based on physiological and DTG PK data. Next, the model was extended with a fetoplacental unit using transplacental kinetics obtained by performing ex vivo dual‐side human cotyledon perfusion experiments. Simulations of fetal exposure after maternal dosing in the third trimester were in accordance with clinically observed DTG cord blood data. Furthermore, the predicted fetal trough plasma concentration (C_trough) following 50 mg q.d. dosing remained above the concentration that results in 90% of viral inhibition. Our integrated approach enables simulation of maternal and fetal DTG exposure, illustrating this to be a promising way to assess DTG PK during pregnancy.

Update on Adverse Effects of HIV Integrase Inhibitors

PURPOSE OF REVIEW

The goal of this paper is to provide an up-to-date review of adverse events related to the class of integrase strand transfer inhibitors (INSTIs), which became the class of choice in few years. We sought answers specifically to issues pertaining to neuropsychiatric adverse events, as well as weight gain, which were the two most important categories of adverse events raised in recent studies based on real-life experience. The primary focus of this paper is on adults with a brief summary on pregnant women and children/adolescents.

RECENT FINDINGS

Dolutegravir (DTG) bears the heaviest burden of neuropsychiatric side effects. Weight gain was reported with all INSTIs, although there are methodological caveats in the analyses and the findings need to be interpreted with caution.Moreover, due to recent findings on neural tube defects in infants exposed to dolutegravir during their peri-conception period, its use is not recommended for women of childbearing age without proper birth control method, while raltegravir remains the only drug which may be prescribed without caution. Given the importance of cognitive and metabolic co-morbidities in people living with HIV in regard to their quality of life, future research needs to focus on long-term effects of INSTIs in relation to these adverse events. Pharmacogenetics seems to be a promising tool. Safety during pregnancy is also another important issue to further clarify.

SUMMARY

INSTIs are a generally well-tolerated class of antiretrovirals (ARV), and has a higher antiviral potency compared to other classes of ARV.Clinicians and patients need however to be aware of some red flags when starting with and monitoring patients on INSTIs.All INSTIs can lead to mild increases in creatinine levels, usually without clinical significance, but caution is needed in patients with low eGFR (<30ml/min), when using other nephrotoxic drugs, such as as tenofovir disoproxil.Neuro-psychiatric (NP) effects are to be monitored with INSTIs, especially with DTG (though reports are at times contradictory); clinicians might want to avoid DTG for patients with history of severe NP symptoms, until clarity is provided.Weight gain was reported with all INSTIs, especially with DTG, with possible differential effects according to sex and ethnicity (female and non-white patients being at increased risk). This is worrying since patients from African descent are at higher risk of cardio-vascular events and increased body mass index (BMI) can cause further increase metabolic risk. There is possibly an additional effect of tenofovir alafenamide (TAF) on weight increase.Discrepancies between clinical trials - with low rates of adverse events - and reports from real-life settings might be due partly to under-representation of some groups of patients in clinical trials, and/or the short duration of follow-up, since some adverse effects may only occur after prolonged exposure.Preliminary data on safety of bictegravir (BIC), from clinical trials and non-trial settings, are very reassuring and seem to show lower rates of adverse events compared to DTG.Elvitegravir/cobicistat (EVG/cobi) need to be used with caution in patients with other co-morbidities given potential for polypharmacy, as it is the case for aging patients, because of the high potential of drug-drug interactions due to effects of the cobicistat booster.We are awaiting the release of cabotegravir (CAB), which could represent a good option for patients struggling with adherence, despite injection site reactions.Pharmacogenetics is a promising way to explore adverse effects occurrence in the INSTI class.

Pharmacokinetic drug evaluation of ritonavir (versus cobicistat) as adjunctive therapy in the treatment of HIV

Introduction: Ritonavir and cobicistat are pharmacoenhancers used to improve the disposition of other HIV antiretrovirals. These drugs are, however, characterized by important pharmacokinetic differences.Areas covered: Here, the authors firstly update the available information on the pharmacokinetics of ritonavir and cobicistat. Subsequently, the review focuses on the description of drug-drug interactions (DDIs) involving cobicistat and comedications that might beneficiate from a shift-back to ritonavir. A MEDLINE Pubmed search for articles published from January 1995 to April 2019 was completed matching the term ritonavir or cobicistat with pharmacokinetics, DDIs, and pharmacology. Moreover, additional studies were identified from the reference list of retrieved articles.Expert opinion: Despite more than 20 years after its introduction on the market, ritonavir still represents a valid option for the treatment of selected HIV-infected patients. The large-scale switch to cobicistat may result in some unexpected DDIs not previously reported for ritonavir. Besides the issue of DDIs, additional advantage of ritonavir over cobicistat is its use in pregnancy, and its availability as single component of pharmaceutical formulations allowing the fine-tuning of antiretroviral regimens in patients with heavy polypharmacy when other unboosted-based therapeutic options cannot be used.

Inhibition of HTLV-1 Infection by HIV-1 First- and Second-Generation Integrase Strand Transfer Inhibitors

More than 10 million people worldwide are infected with the retrovirus human T-cell lymphotropic virus type 1 (HTLV-1). Infection phenotypes can range from asymptomatic to severe adult T-cell leukemia/lymphoma (ATLL) and HTLV-1-associated myelopathy. HTLV-1, like human immunodeficiency virus type 1 (HIV-1), is a blood-borne pathogen and viral infection happens in a similar fashion, with the major mode of transmission through breastfeeding. There is a strong correlation between time of infection and disease development, with a higher incidence of ATLL in patients infected during childhood. There is no successful therapeutic or preventative regimen for HTLV-1. It is therefore essential to develop therapies to inhibit transmission or block the onset/development of HTLV-1 associated diseases. Recently, we have seen the overwhelming success of integrase strand transfer inhibitors (INSTIs) in the treatment of HIV-1. Previously, raltegravir was shown to inhibit HTLV-1 infection. Here, we tested FDA-approved and two Phase II HIV-1 INSTIs in vitro and in a cell-to-cell infection model and show that they are highly active in blocking HTLV-1 infection, with bictegravir (EC₅₀ = 0.30 ± 0.17 nM) performing best overall. INSTIs, in particular bictegravir, are more potent in blocking HTLV-1 transmission than tenofovir disproxil fumarate (TDF), an RT inhibitor. Our data suggest that HIV-1 INSTIs could present a good clinical strategy in HTLV-1 management and justifies the inclusion of INSTIs in clinical trials.

Evaluating cabotegravir/rilpivirine long-acting, injectable in the treatment of HIV infection: emerging data and therapeutic potential

Cabotegravir and rilpivirine long-acting injectable antiretroviral therapy for the treatment of HIV-1 infection brings promise of a new mode of delivery and potential solutions to some problems of oral therapy, but also new challenges and unanswered questions. Adding to the increasing body of evidence for newer two-drug combinations, phase II and phase III trial data to date demonstrate cabotegravir and rilpivirine combination injectable therapy to be non-inferior to selected oral triple-therapy alternatives. Most importantly, this therapy is reported to be acceptable to individuals taking the 4-weekly or 8-weekly injections, despite frequent injection-site reactions. Key outstanding questions include management of missed or delayed dosing, drug interactions and management of virological failure, as well as the efficacy of cabotegravir and rilpivirine in all HIV-1 subtypes. We describe clinical evidence to date and efficacy and challenges in selected populations, including women; those with prior virological failure; individuals with a history of difficulty adhering to oral therapy and individuals with co-infections. We await real-world data and longer-term evidence while moving forward to this new era of antiretroviral therapy.

Pharmacokinetics and Safety of the Integrase Inhibitors Elvitegravir and Dolutegravir in Pregnant Women With HIV

Objective: To synthesize data on the pharmacokinetics and safety of dolutegravir and elvitegravir in pregnant women living with HIV. Data Sources: A PubMed, EMBASE, Web of Science, and Google Scholar literature search (January 2010 to December 2018) was performed using the search terms dolutegravir, elvitegravir, women, pregnant*, and HIV. Additional reports were identified from conference abstracts and review of reference lists. Study Selection and Data Extraction: English-language studies reporting pharmacokinetic and/or safety data in pregnant women receiving dolutegravir or elvitegravir/cobicistat were included. Data Synthesis: A total of 17 studies were selected. Studies demonstrated a modest decrease in dolutegravir concentrations in pregnancy. Preliminary data suggest an increased risk of neural tube defects when dolutegravir is used at the time of conception. Available pharmacokinetic data in pregnant women showed significantly reduced plasma concentrations of elvitegravir/cobicistat which may increase the risk of virological failure. Current guidelines recommend that dolutegravir should not be initiated in women who have the potential to become pregnant or women in their first trimester of pregnancy and elvitegravir/cobicistat should be avoided during pregnancy. Relevance to Patient Care and Clinical Practice: This review highlights pharmacokinetic and safety data for dolutegravir and elvitegravir/cobicistat in pregnant women. Clinicians need to be aware of these data to convey the risks and benefits of using these agents in women of child-bearing potential. Conclusions: Changes in guideline recommendations reflect emerging data regarding the use of dolutegravir and elvitegravir/cobicistat in pregnancy. Until further information is available, raltegravir or other first-line agents are recommended for women with HIV planning to become pregnant.