Metformin for People With CFRD on CFTR Modulator Therapy to Improve Ion Channel Function

April 10, 2026 updated by: Matthias Salathe, MD, University of Kansas Medical Center

An Open Label Clinical Trial of Metformin in Those With CFRD on CFTR Modulator Therapy to Improve Ion Channel Function

The purpose of this study is to assess the efficacy of metformin to improve airway ion channel function in those with CF-related diabetes (CFRD)

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Up to 30 patients with CFRD on highly effective CFTR modulator therapy who meet criteria and agree to participation in the study will be placed on metformin. There will be a dose-escalation starting with 500mg twice daily for a week, followed by 500mg in the AM and 1000mg in the PM for another week and finally followed by 1000mg twice daily for 14 weeks. To minimize risk of B12 deficiency, a known side effect of long-term metformin use, we will also provide a supplement of 1000 μg oral cyanocobalamin daily for the duration of the trial

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
30

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

  • United States
    • Kansas
      • Kansas City, Kansas, United States, 66160
        • Recruiting
        • University of Kansas Medical Center
        • Contact:
        • Contact:
          • Carolina Aguiar
          • Phone Number: 9139459295
        • Sub-Investigator:
          • Charles D Bengtson, M.D.
        • Sub-Investigator:
          • Andreas Schmid, M.D.

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

14 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion criteria:

  1. Age >18 years with a prior diagnosis of CF.
  2. Use of ivacaftor or elexacaftor/tezacaftor/ivacaftor or vanzacaftor/tezacaftor/deutivacaftor for 30 days prior to day 0

  3. Diagnosis of CFRD with evidence of continued glucose intolerance at least 6 months after starting qualifying modulator therapy will be based upon one of the following:

    1. Insulin use
    2. Hemoglobin A1C >6.5%
    3. Fasting glucose >126 mg/dl
    4. Non-fasting glucose >200 mg/dl (random or as part of a 2-hr OGTT)

Exclusion criteria:

  1. Prior lung or liver transplant
  2. Use of supplemental oxygen
  3. BMI <18
  4. CF pulmonary exacerbation requiring hospitalization or intravenous antibiotics in the preceding 30 days
  5. Systemic corticosteroid or regular non-steroidal anti-inflammatory use in the preceding 30 days
  6. Cardiac, renal (creatinine clearance <45 mL/minute), neurologic, psychiatric, endocrine or neoplastic diseases that are judged to interfere with participation in the study
  7. Alanine aminotransferase, aspartate aminotransferase or alkaline phosphatase >1.5X the upper limit of normal; bilirubin >3 mg/dL
  8. Taking medications that interact with metformin.
  9. Vitamin B12 deficiency
  10. Pregnancy or lactation
  11. Inability or unwillingness to comply with an approved contraceptive method during the study period (females of childbearing age)
  12. Use of medications known to be strong CYP inducers or moderate to strong CYP inhibitors
  13. In the opinion of the investigator any severe or acute or chronic condition or laboratory abnormality that may increase the risk associated with trial participation or make the subject inappropriate for enrollment
  14. Participation in another interventional trial that, in the opinion of the investigator, has the potential to affect the primary outcome

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Metformin dose regimen A
patients with CFRD on highly effective CFTR modulator therapy who meet criteria and agree to participation in the study will be placed on metformin. There will be a dose-escalation starting with 500mg twice daily for a week, followed by 500mg in the AM and 1000mg in the PM for another week and finally followed by 1000mg twice daily for 14 weeks.
Drug: Metformin Hydrochloride
1000 mg twice daily
Other Names:
  • Glucophage

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Change in BK channel gene expression
Time Frame: Baseline through week 14 of metformin treatment
Levels of LRRC26 (big potassium channel regulatory subunit) mRNA will be measured by polymerase chain reaction from nasal cells acquired via brushing
Baseline through week 14 of metformin treatment

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Change in BK function, as measured by nasal potential difference testing
Time Frame: Baseline through week 14 of metformin treatment
Nasal potential difference testing measures direct BK current in the nasal epithelium, with greater current indicating greater BK function
Baseline through week 14 of metformin treatment
Change in receptor for receptor for advanced glycation end products (RAGE) gene expression
Time Frame: Baseline through week 14 of metformin treatment
Levels of RAGE mRNA will be measured by polymerase chain reaction from nasal cells acquired via brushing
Baseline through week 14 of metformin treatment
Change in advanced glycation end products (AGE)
Time Frame: Baseline through week 14 of metformin treatment
Plasma levels of AGE, receptor for AGE (RAGE), soluble RAGE and S100A12 will be quantified by ELISA
Baseline through week 14 of metformin treatment
Change in sweat chloride
Time Frame: Baseline through week 14 of metformin treatment
Measured as a secondary marker of CFTR function, with lower levels indicating greater CFTR function
Baseline through week 14 of metformin treatment
Change in lung function
Time Frame: Baseline through week 14 of metformin treatment
Measured by percent predicted forced expiatory volume in one second captured on spirometry (FEV1)
Baseline through week 14 of metformin treatment
Change in Quality of Life (CFQ-R)
Time Frame: Baseline through week 14 of metformin treatment
Measured by Patient Reported Outcome measurement tool called CFQ-R (validated)
Baseline through week 14 of metformin treatment
Change in airway inflammatory markers
Time Frame: Baseline through week 14 of metformin treatment
Inflammatory markers (interleukin-1beta, interleukin-6, interleukin-8, transforming growth factor beta1, tissue necrosis factor-alpha, matrix metalloproteinase-9 and cyclooxygenase-2) collected from nasal fluid will be measured by enzyme linked immunosorbent assay (ELISA)
Baseline through week 14 of metformin treatment
Safety of metformin
Time Frame: Baseline through week 14 of metformin treatment
Number of adverse events during study period
Baseline through week 14 of metformin treatment
Pharmacokinetics of metformin
Time Frame: Week 14 of metformin treatment
Plasma levels of metformin will be quantified by liquid chromatography-mass spectrometry
Week 14 of metformin treatment

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
University of Kansas Medical Center

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Matthias A Salathe, M.D., Professor

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
February 14, 2022

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
December 30, 2027

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
July 15, 2028

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
August 24, 2020

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 24, 2020

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
August 28, 2020

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
April 15, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 10, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
April 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • STUDY00146063/STUDY00161734
  • R01HL157942-01 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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