Home Medicine Isotope dilution LC-MS/MS quantification of the cystic fibrosis transmembrane conductance regulator (CFTR) modulators ivacaftor, lumacaftor, tezacaftor, elexacaftor, and their major metabolites in human serum
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Isotope dilution LC-MS/MS quantification of the cystic fibrosis transmembrane conductance regulator (CFTR) modulators ivacaftor, lumacaftor, tezacaftor, elexacaftor, and their major metabolites in human serum

  • Katharina Habler ORCID logo , Anne-Sophie Kalla , Michael Rychlik , Mathias Bruegel , Daniel Teupser , Susanne Nährig , Michael Vogeser and Michael Paal ORCID logo EMAIL logo
Published/Copyright: October 20, 2021
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Clinical Chemistry and Laboratory Medicine (CCLM)
From the journal Clinical Chemistry and Laboratory Medicine (CCLM) Volume 60 Issue 1

Abstract

Objectives

Cystic fibrosis (CF) transmembrane conductance regulator (CFTR) modulators have revolutionized the therapeutic landscape in CF treatment. These vital drugs are extensively metabolized via CYP3A, so caution must be exercised in multimodal CF therapy because of the risk of adverse drug interactions. Our goal was to develop a highly sensitive assay for the purpose of therapeutic drug monitoring (TDM) in diagnostic laboratories.

Methods

After protein precipitation, the CFTR modulators ivacaftor, lumacaftor, tezacaftor, elexacaftor, and their metabolites ivacaftor-M1, ivacaftor-M6, and tezacaftor-M1 were separated with a two-dimensional chromatography setup within 5 min, and quantified with stable isotope-labeled internal standards. The method was validated according to the European Medicines Agency (EMA) guideline on bioanalytical method validation and applied to CF patient samples.

Results

Inaccuracy was ≤7.0% and the imprecision coefficient of variation (CV) was ≤8.3% for all quality controls (QCs). The method consistently compensated for matrix effects, recovery, and process efficiency were 105–115 and 96.5–103%, respectively. Analysis of CF serum samples provided concentrations comparable to the pharmacokinetic profile data reported in the EMA assessment report for the triple combination therapy Kaftrio.

Conclusions

We hereby present a robust and highly selective isotope dilution liquid chromatography tandem mass spectrometry (ID-LC-MS/MS) assay for the simultaneous quantification of the so far approved CFTR modulators and their metabolites in human serum. The assay is suitable for state-of-the-art pharmacovigilance of CFTR modulator therapy in CF patients, in order to maximize safety and efficacy, and also to establish dose-response relationships in clinical trials.

Keywords: cystic fibrosis (CF); cystic fibrosis transmembrane conductance regulator (CFTR) modulators; isotope dilution liquid chromatography tandem mass spectrometry (ID-LC-MS/MS); therapeutic drug monitoring (TDM)
Corresponding author: Michael Paal, Institute of Laboratory Medicine, University Hospital, LMU Munich, Marchioninistr. 15, 81377 Munich, Germany, Phone: +49 89 4400 73200, Fax +49 89 4400 73240, E-mail:

Funding source: Friedrich-Baur-Stiftung

  1. Research funding: Michael Paal received a research grant (award number 62/20) from the Friedrich-Baur-Stiftung. The funding source had no involvement in the research.

  2. Author contributions: All authors have accepted responsibility for the entire content of this manuscript and approved its submission.

  3. Competing interests: Authors state no conflict of interest.

  4. Informed consent: Informed consent was obtained from all individuals included in this study.

  5. Ethical approval: Research related to human use has been complied with all the relevant national regulations, institutional policies and in accordance the tenets of the Helsinki Declaration (as revised in 2013), and has been approved by the institutional review board of the Ludwig-Maximilians-Universität (protocol code 20-999).

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Supplementary Material

The online version of this article offers supplementary material (https://doi.org/10.1515/cclm-2021-0724).

Received: 2021-06-22
Accepted: 2021-09-07
Published Online: 2021-10-20
Published in Print: 2022-01-26

© 2021 Walter de Gruyter GmbH, Berlin/Boston

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https://doi.org/10.1515/cclm-2021-0724
Keywords for this article
cystic fibrosis (CF); cystic fibrosis transmembrane conductance regulator (CFTR) modulators; isotope dilution liquid chromatography tandem mass spectrometry (ID-LC-MS/MS); therapeutic drug monitoring (TDM)

Articles in the same Issue

  1. Frontmatter
  2. Editorials
  3. EU health policy is on the brink of a spectacular own-goal that will harm patients and hamper innovation
  4. Theranos revisited: the trial and lessons learned
  5. Reviews
  6. Review and evolution of guidelines for diagnosis of COVID-19 vaccine induced thrombotic thrombocytopenia (VITT)
  7. High-sensitivity cardiac troponins in pediatric population
  8. Opinion Papers
  9. Implementation of the new EU IVD regulation – urgent initiatives are needed to avert impending crisis
  10. Exploration of novel biomarkers for hypertensive disorders of pregnancy by comprehensive analysis of peptide fragments in blood: their potential and technologies supporting quantification
  11. General Clinical Chemistry and Laboratory Medicine
  12. Total lab automation: sample stability of clinical chemistry parameters in an automated storage and retrieval module
  13. Instability of corticotropin during long-term storage – myth or reality?
  14. External quality assessment of serum indices: Spanish SEQC-ML program
  15. Comparison of two LC-MS/MS methods for the quantification of 24,25-dihydroxyvitamin D3 in patients and external quality assurance samples
  16. Isotope dilution LC-MS/MS quantification of the cystic fibrosis transmembrane conductance regulator (CFTR) modulators ivacaftor, lumacaftor, tezacaftor, elexacaftor, and their major metabolites in human serum
  17. Hematology and Coagulation
  18. The development of autoverification system of lymphocyte subset assays on the flow cytometry platform
  19. Cancer Diagnostics
  20. Comparison of the QuikRead go® point-of-care faecal immunochemical test for haemoglobin with the FOB Gold Wide® laboratory analyser to diagnose colorectal cancer in symptomatic patients
  21. Evaluation of circulating Dickkopf-1 as a prognostic biomarker in ovarian cancer patients
  22. Cardiovascular Diseases
  23. Soluble CD40 ligand and outcome in patients with coronary artery disease undergoing percutaneous coronary intervention
  24. Diabetes
  25. Lot variation and inter-device differences contribute to poor analytical performance of the DCA Vantage™ HbA1c POCT instrument in a true clinical setting
  26. Infectious Diseases
  27. Lipase elevation in serum of COVID-19 patients: frequency, extent of increase and clinical value
  28. Acknowledgment
  29. Acknowledgment
  30. Letters to the Editors
  31. Presepsin value predicts the risk of developing severe/critical COVID-19 illness: results of a pooled analysis
  32. Measuring accuracy of the neutralizing activity of COVID-19 convalescent plasma
  33. Evaluation of reference intervals for classical and alternative pathway functional complement assays
  34. Reference values for plasma neurofilament light chain in healthy Chinese children
  35. Cerebrospinal fluid neurogranin in Alzheimer’s disease studies: are immunoassay results interchangeable?
  36. Pepsin pretreatment corrects underestimation of 25-hydroxyvitamin D measurement by an automated immunoassay in subjects with high vitamin D binding protein levels
  37. A conspicuous reduced plasma creatinine: the first presenting sign of Waldenstrom macroglobulinemia
  38. Effect of non-linearity on rheumatoid factor assay in Beckman system IMMAGE800
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