Pharmacokinetics of CFTR Modulators in Pregnant Individuals and in Postpartum Breastfeeding Mothers

Study Overview
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Brief Summary
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This study aims to evaluate the pharmacokinetic changes during pregnancy, postpartum, and in breast milk in cystic fibrosis patients receiving a cystic fibrosis transmembrane conductance regulator (CTFR) modulator, including Elexacaftor, Tezacaftor, Ivacaftor, or Lumacaftor.

Detailed Description
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The advent of cystic fibrosis transmembrane conductance regulator (CFTR) therapy has significantly increased the life expectancy for individuals with cystic fibrosis (CF). As a result, adults with CF are more likely to have families than they have in the past. Although the overall pregnancy rate among women with CF age 18-44 is declining (mirroring trends in the general population), the overall number of pregnancies is increasing due to the increasing number of adults with CF. However, little is known about CFTR modulator use in pregnant or breastfeeding mothers, as outlined in a recent review of CF-therapies in pregnant and breastfeeding women. Presently, there is one report of an uncomplicated pregnancy during ivacaftor use, and one case of a successful pregnancy in a woman who was maintained on lumacaftor/ivacaftor with reported maternal and fetal drug levels. In this study, we aim to study the pharmacokinetics of CFTR modulators in pregnancy as well as while breastfeeding. This information will hopefully improve counseling while offering them for CF patients given the tremendous improvements seen in non-pregnant adults.

Official Title
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Pharmacokinetics of CFTR Modulators in Pregnant Individuals and in Postpartum Breastfeeding Mothers

Conditions
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Cystic Fibrosis, Pregnancy

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Female 18 years of age and older Female who has a diagnosis of cystic fibrosis Female who is taking cystic fibrosis transmembrane conductance regulator (CFTR) modulator medication during pregnancy and postpartum Exclusion Criteria: Female < 18 years of age Female with cystic fibrosis who is not taking cystic fibrosis transmembrane conductance regulator (CFTR) modulator medication during pregnancy and postpartum Participant has contraindication to breastfeeding or not planning to breastfeed

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Participants receiving CFTR modulator therapy - Trikafta<br>This is a single arm study. Participants in this study are receiving CFTR modulator therapy. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in levels of CTFR modulator in blood | Quantification of CTFR modulator in blood will be performed using Liquid Chromatography-Mass Spectrometry (LC-MS) and reported in units of ng/kg. Blood will be collected every 3 months during pregnancy and at the sampling of breast milk 0-4 days after giving birth. | approximately 9 months | 
| Change in levels of CTFR modulator in breast milk | Quantification of CTFR modulator in blood will be performed using Liquid Chromatography-Mass Spectrometry (LC-MS) and reported in units of ng/ml. Breast milk will be collected following feeding of the infant 0-4 days following birth of the infant. | 4 days | 
| Change in levels of CTFR modulator in umbilical cord blood | Quantification of CTFR modulator in blood will be performed using Liquid Chromatography-Mass Spectrometry (LC-MS) and reported in units of ng/kg. Umbilical cord blood will be collected once at the time the infant is born. | at birth of the infant |