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NCT Number: NCT05818319

Cystic Fibrosis in the Kidney: Monitoring the Effectiveness of Elexacaftor/tezacaftor/ivacaftor in Urine After a Short Pause of Therapy

In cystic fibrosis (CF) renal base excretion is impaired, due to mutations in the Cystic Fibrosis Transmembrane Regulator (CFTR) gene, since CFTR function is crucial in regulation of the kidney's HCO3- excretion.

The investigators suggest that challenged urine HCO3- excretion is a biomarker of CFTR function, which can be used to evaluate the extent of CFTR dysfunction and the possible correcting effects of CFTR modulating therapy.

This study aims to evaluate changes in challenged urine HCO3- excretion in CF patients, who are currently in treatment with the triple CFTR modulator combination therapy, Elexacaftor/tezacaftor/ivacaftor (ETI), before, during, and after a short treatment pause.

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Key information

Conditions

Cystic Fibrosis (CF) CFTR Gene Mutation Congenital, Hereditary, and Neonatal Diseases and Abnormalities Cystic Fibrosis Digestive System Diseases Genetic Diseases, Inborn Infant, Newborn, Diseases Lung Diseases Pancreatic Diseases Respiratory Tract Diseases

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Department of Infectious Diseases, Aarhus University Hospital

Aarhus C, Central Jutland, 8000, Denmark

Location status: Recruiting

Location contact

Amalie Rousing

CONTACT

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Adult (age >17 years) CF patients.
  • Normal kidney function estimated by eGFR>90.
  • Adults capable of understanding and voluntarily consenting.

Exclusion criteria

  • Critical acute illness.
  • Severe lung disease (ppFEV1<40%).
  • Adults not capable of understanding and voluntarily consenting.

Treatment and study plan

12 hours ETI pause

Other

Patients with CF are randomly allocated to ETI pause lasting 12 hours.

36 hours ETI pause

Other

Patients with CF are randomly allocated to ETI pause lasting either 36 hours.

60 hours ETI pause

Other

Patients with CF are randomly allocated to ETI pause lasting either 60 hours.

Primary outcomes

  1. Difference in cumulative urine bicarbonate excretion before, during, and after ETI pause.

    Time frame: At baseline, after 12/36/60 hours of therapy pause and after therapy is resumed.

    Challenged urine HCO3- test: Quantification of urine bicarbonate excretion after an acute oral NaHCO3 challenge before, under, and after ETI pause.

  2. Link between changes in ETI plasma concentration and changes in urine bicarbonate excretion.

    Time frame: At baseline, after 12/36/60 hours of therapy pause and after therapy is resumed.

    Venous blood sampling: ETI plasma concentration measurement. Challenged urine HCO3- test: Quantification of urine bicarbonate excretion

Secondary outcomes

  1. Link between plasma acid-base status and urine acid-base excretion.

    Time frame: At baseline, after 12/36/60 hours of therapy pause and after therapy is resumed.

    Venous blood sampling: Venous acid-base measurements.

  2. Changes in plasma concentration of ETI during the trial.

    Time frame: At baseline, after 12/36/60 hours of therapy pause and after therapy is resumed.

    Venous blood sampling: ETI plasma concentration measurement.

  3. Changes in acid-base and fluid status during the trial.

    Time frame: At baseline, after 12/36/60 hours of therapy pause and after therapy is resumed.

    Venous blood sampling: Venous acid-base and fluid measurements.

  4. Changes in electrolytes during the trial.

    Time frame: At baseline, after 12/36/60 hours of therapy pause and after therapy is resumed.

    Venous blood sampling: Venous electrolyte measurements. Challenged HCO3- urine test: Urine electrolyte measurements.

Study contacts

Contact information is provided by the study sponsor or research team.

Amalie Q. Rousing, BM

CONTACT

[email protected]

Sponsors and collaborators

Lead sponsor

University of Aarhus

Other

Registry information

Important dates

Study start
2023
Primary completion
2025
Study completion
2025
First posted
Apr 18, 2023
Registry last updated
Feb 19, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

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This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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