The Balance between the Safety of Mother, Fetus, and Newborn Undergoing Cystic Fibrosis Transmembrane Conductance Regulator Treatments during Pregnancy

Fetal drug exposure after maternally administered CFTR modulators Elexacaftor/Tezacaftor/Ivacaftor in a rat model

BACKGROUND

The potential effects of the very effective cystic fibrosis triple combination drug, Elexacaftor/Tezacaftor/Ivacaftor (ETI) in pregnancy on prenatal development of offspring remain largely unknown.

RESEARCH QUESTION

We aimed to investigate the fetal tissue distribution pattern of maternally administered ETI by placental transfer in the rat fetuses.

STUDY DESIGN AND METHODS

Sprague Dawley pregnant rats were administered ETI (6.7 mg/kg/d elexacaftor + 3.5 mg/kg/d tezacaftor + 25 mg/kg/d ivacaftor) traced with [3 H]-ivacaftor in single dose acute experiments (intraperitoneal injection) or treated orally with ETI (the same dose) for 7 days in sub-chronic experiments. Fetal tissue samples were collected at embryonic day (E) 19 and analyzed using liquid scintillation counting for acute experiments or liquid chromatography-mass spectrometry for sub-chronic experiments.

RESULTS

On day E19, after acute exposure, the entry of ivacaftor into fetal brain (brain/plasma concentration ratios <50%) was significantly lower than to other tissues (>100%). However, after sub-chronic exposure, the entry of all 3 components into the developing brain was comparably extensive as into other tissues (tissue/plasma ratios, 260 - 1000%). Each component of ETI accumulated in different fetal tissues to approximately equal extent. Inter-litter differences on fetal drug distribution were found in cortex for ivacaftor, muscle for tezacaftor and cortex and mid/hindbrain for elexacaftor. Fetal plasma concentrations of ETI (ng/mL) were variable between litters. The entry of ivacaftor and tezacaftor into adult brain appeared to be restricted (<100%).

INTERPRETATION

Fetal rats are exposed to maternally ingested ETI after sub-chronic exposure, potentially impacting fetal development. The brain entry data highlights the need for attention be paid to any long-term potential effects ETI exposure could have on normal brain development.

Ocular development after highly effective modulator treatment early in life

Highly effective cystic fibrosis (CF) transmembrane conductance regulator (CFTR) modulator therapies (HEMT), including elexacaftor-tezacaftor-ivacaftor, correct the underlying molecular defect causing CF. HEMT decreases general symptom burden by improving clinical metrics and quality of life for most people with CF (PwCF) with eligible CFTR variants. This has resulted in more pregnancies in women living with CF. All HEMT are known to be able pass through the placenta and into breast milk in mothers who continue on this therapy while pregnant and breast feeding. Toxicity studies of HEMT in young rats demonstrated infant cataracts, and case reports have reported the presence of congenital cataracts in early life exposure to HEMT. This article reviews the evidence for how HEMT influences the dynamic and interdependent processes of healthy and abnormal lens development in the context of HEMT exposure during pregnancy and breastfeeding, and raises questions that remain unanswered.

In Utero Mapping and Development Role of CFTR in Lung and Gastrointestinal Tract of Cystic Fibrosis Patients

In cystic fibrosis (CF) the ability of the CF transmembrane conductance regulator (CFTR) protein to mediate chloride and water transport is disrupted. While much progress has been made in CF research leading to effective treatments to improve CFTR function, including small molecule modulators, patients present with varying disease manifestations and responses to therapy. For many CF-affected organs, disease onset is known to occur during in utero development before treatments can be administered and progresses over time leading to irreversible damage to these organs. Thus, the role of functional CFTR protein, in particular, during early development needs to be further elucidated. Studies have detected CFTR proteins at very early gestational stages and revealed temporally and spatially variable CFTR expression patterns in fetuses, suggesting a potential role of CFTR in fetal development. However, the actual mechanisms of how defective CFTR in CF results in fetal morphogenetic abnormalities are yet to be established. This review aims to summarize fetal CFTR expression patterns specifically in the lung, pancreas, and gastrointestinal tract (GIT), as compared to adult patterns. Case studies of structural abnormalities in CF fetuses and newborns and the role of CFTR in fetal development will also be discussed.

The choroid plexus: a missing link in our understanding of brain development and function

Studies of the choroid plexus lag behind those of the more widely known blood-brain barrier, despite a much longer history. This review has two overall aims. The first is to outline long-standing areas of research where there are unanswered questions, such as control of cerebrospinal fluid (CSF) secretion and blood flow. The second aim is to review research over the past 10 years where the focus has shifted to the idea that there are choroid plexuses located in each of the brain's ventricles that make specific contributions to brain development and function through molecules they generate for delivery via the CSF. These factors appear to be particularly important for aspects of normal brain growth. Most research carried out during the twentieth century dealt with the choroid plexus, a brain barrier interface making critical contributions to the composition and stability of the brain's internal environment throughout life. More recent research in the twenty-first century has shown the importance of choroid plexus-generated CSF in neurogenesis, influence of sex and other hormones on choroid plexus function, and choroid plexus involvement in circadian rhythms and sleep. The advancement of technologies to facilitate delivery of brain-specific therapies via the CSF to treat neurological disorders is a rapidly growing area of research. Conversely, understanding the basic mechanisms and implications of how maternal drug exposure during pregnancy impacts the developing brain represents another key area of research.

Family-building and parenting considerations for people with cystic fibrosis

As people with cystic fibrosis (CF) live longer and healthier lives, increasing numbers are considering the full range of reproductive options for their futures, including parenthood, pregnancy, or pregnancy prevention. As the face of CF changes, the CF care model must adapt to meet the reproductive health needs of both parents and nonparents with CF. This article summarizes the reproductive goals and family-building concerns faced by people with CF, including fertility, pregnancy, and alternative paths to parenthood, the impact of parenthood on mental and physical health, and important future research.

Cystic Fibrosis Transmembrane Conductance Regulator Modulators During Pregnancy: A Case Series

Cystic fibrosis (CF) is the most common genetic disease in the United States (US) and, with the development of newer therapeutics, there is increased fertility among women with CF. We present a series of pregnant patients taking novel CF transmembrane conductance regulator (CFTR) modulators and summarize pertinent clinical considerations. All women conceived within four months after starting elexacaftor-ivacaftor-tezacaftor. Pulmonary function was stable before and during pregnancy. One patient developed transaminitis necessitating discontinuation of the medication mid-trimester. All patients delivered healthy neonates between 36-38 weeks of gestation with uncomplicated postpartum courses. No birth defects were encountered. Given that newly introduced CFTR modulators may increase fertility among CF patients, contraception counseling, pulmonary function monitoring, liver function monitoring, and multi-disciplinary care are important pillars of management.

Advantages and Disadvantages of Using Magnetic Nanoparticles for the Treatment of Complicated Ocular Disorders

Nanomaterials provide enormous opportunities to overcome the limitations of conventional ocular delivery systems, such as low therapeutic efficacy, side effects due to the systemic exposure, or invasive surgery. Apart from the more common ocular disorders, there are some genetic diseases, such as cystic fibrosis, that develop ocular disorders as secondary effects as long as the disease progresses. These patients are more difficult to be pharmacologically treated using conventional drug routes (topically, systemic), since specific pharmacological formulations can be incompatible, display increased toxicity, or their therapeutic efficacy decreases with the administration of different kind of chemical molecules. Magnetic nanoparticles can be used as potent drug carriers and magnetic hyperthermia agents due to their response to an external magnetic field. Drugs can be concentrated in the target point, limiting the damage to other tissues. The other advantage of these magnetic nanoparticles is that they can act as magnetic resonance imaging agents, allowing the detection of the exact location of the disease. However, there are some drawbacks related to their use in drug delivery, such as the limitation to maintain efficacy in the target organ once the magnetic field is removed from outside. Another disadvantage is the difficulty in maintaining the therapeutic action in three dimensions inside the human body. This review summarizes all the application possibilities related to magnetic nanoparticles in ocular diseases.

"Fertility and Pregnancy in Cystic fibrosis"

People with Cystic fibrosis (pwCF) have experienced increased survival and wellbeing in recent decades, such that more than half of those living with CF are adults. Consequently, sexual and reproductive health is increasingly important for pwCF as many are considering parenthood. Most men and some women with CF (wwCF) will have reduced fertility, which in both sexes is multifactorial. However, unplanned pregnancies in women are not rare, and contraception and its interaction with CF complications need to be addressed by the CF team. Reduced fertility may be overcome in most pwCF through use of assisted reproductive technologies; however, the risk of having offspring with CF must be considered. Most wwCF will have normal pregnancies, but premature birth is common especially in the setting of reduced lung function and CF related diabetes (CFRD); optimization of treatment is recommended during pregnancy planning. Parenting imposes an increased burden on pwCF, with the challenges of caring for the newborn, postpartum physiologic changes and maintaining CF treatments. Most drugs used to treat CF are considered safe in pregnancy and lactation, but exceptions need to be acknowledged, including the limited data regarding safety of CF transmembrane conductance regulator (CFTR) modulators during conception, pregnancy, and lactation. As most pwCF are eligible for highly effective CFTR modulators, fertility, contraception, and pregnancy in people with CF is changing. Prospective studies regarding these issues in people treated with CFTR modulators are paramount to provide evidence-based guidance for management in the current era of CF care.

Anti-Inflammatory Influences of Cystic Fibrosis Transmembrane Conductance Regulator Drugs on Lung Inflammation in Cystic Fibrosis

Cystic fibrosis (CF) is caused by a defect in the cystic fibrosis transmembrane conductance regulator protein (CFTR) which instigates a myriad of respiratory complications including increased vulnerability to lung infections and lung inflammation. The extensive influx of pro-inflammatory cells and production of mediators into the CF lung leading to lung tissue damage and increased susceptibility to microbial infections, creates a highly inflammatory environment. The CF inflammation is particularly driven by neutrophil infiltration, through the IL-23/17 pathway, and function, through NE, NETosis, and NLRP3-inflammasome formation. Better understanding of these pathways may uncover untapped therapeutic targets, potentially reducing disease burden experienced by CF patients. This review outlines the dysregulated lung inflammatory response in CF, explores the current understanding of CFTR modulators on lung inflammation, and provides context for their potential use as therapeutics for CF. Finally, we discuss the determinants that need to be taken into consideration to understand the exaggerated inflammatory response in the CF lung.

Entry of cystic fibrosis transmembrane conductance potentiator ivacaftor into the developing brain and lung

BACKGROUND

The potential effects of ivacaftor during pregnancy and breastfeeding on the offspring are still unknown. This study aimed to investigate pre-/postnatal age-related entry into the brain and lungs and transfer of maternally administered drug by the placental and via the milk.

METHODS

In acute experiments Sprague Dawley rats at embryonic day (E) 19, postnatal days (P) 4, 9, 16, and adult were administered an intraperitoneal injection of ivacaftor (40 mg/kg) traced with [3H] ivacaftor. To determine tissue entry, plasma, cerebrospinal fluid (CSF), lungs and brains were collected, and radioactivity measured using liquid scintillation counting. For long term experiments pregnant dams were orally treated at 25 mg/kg/day for 7 days and pups collected at E19. For postnatal pups, dams received treatment for 7 or 14 days and pups were collected at P6, 9, 13 and 16. To estimate placental and milk transfer concentration of ivacaftor in pup & maternal plasma was determined by liquid chromatography-mass spectrometry.

RESULTS

At all ages, entry of ivacaftor into lungs, following either acute or prolonged exposure, was much higher than into brain & CSF. Brain entry appeared higher at earlier ages. Transfer across the placenta and breast milk. was estimated to be around ~40% of maternal plasma.

CONCLUSIONS

Fetal and postnatal rats were exposed to maternally administered ivacaftor via placental and milk transfer. Preferential entry in the lungs at all ages suggests the possibility that exposing CF babies to maternally administered ivacaftor could be beneficial for limiting progression of CF pathology in early development.

Multiple Reaction Monitoring Mass Spectrometry for the Drug Monitoring of Ivacaftor, Tezacaftor, and Elexacaftor Treatment Response in Cystic Fibrosis: A High-Throughput Method

Ivacaftor-tezacaftor and ivacaftor-tezacaftor-elexacaftor are new breakthrough cystic fibrosis (CF) drug combinations that directly modulate the activity and trafficking of the defective CF transmembrane conductance regulator protein (CFTR) underlying the CF disease state. Currently, in the hospital setting, there are no therapeutic drug monitoring assays for these very expensive, albeit, life-saving drugs. A rapid and precise novel method for the quantification of ivacaftor, its metabolites, tezacaftor, and elexacaftor, in human plasma was developed and validated using multiple reaction monitoring mass spectrometry (MRM/MS). The MRM/MS analytical method was validated at a concentration range of 0.0025-1 μg/mL for ivacaftor, ivacaftor-M1, ivacaftor-M6, tezacaftor, and elexacaftor in human plasma. The method displayed good accuracy (90.62-94.51%) and reproducibility (99.91-100%) including at low concentrations 0.01 μg/mL. With a mobile phase consisting of [acetonitrile/water]/0.1% formic acid (70:30 v/v) at a flow rate of 0.5 mL/min, a linear correlation was observed over a concentration range of 0.0025-1 μg/mL in human plasma for ivacaftor (R ² = 0.9865105), ivacaftor-M1 (R ² = 0.9852684), ivacaftor-M6 (R ² = 0.9911764), tezacaftor (R ² = 0.98742470), and elexacaftor (R ² = 0.9897608). The reported method can accurately quantify ivacaftor, ivacaftor-M1, ivacaftor-M6, tezacaftor, and elexacaftor at low concentrations in human plasma. We have established a cost-efficient and timely method for measuring ivacaftor, its metabolites, and tezacaftor with or without elexacaftor in human plasma suitable for high-throughput applications in the hospital settings or clinical trials.