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Not yet taking people in United StatesPhase 2

Verapamil for Blood Sugar Problems in Teens and Adults With Cystic Fibrosis

Tests verapamil on insulin-making cells in people with cystic fibrosis and abnormal blood sugar.

Key facts

Who runs it
Rhode Island Hospital
Where
Boston and Providence, United StatesSee the 2 sites
Trial code
Registry title
Verapamil Effect in Cystic Fibrosis-related Dysglycemia
Status
Not yet recruiting
Phase
Phase 2
People taking part
30 people, planned
Started
1 Aug 2026
Expected to end
31 Aug 2028
Type of study
Interventional
Treatments tested
  • Verapamil Hydrochloride
Record updated
9 July 2026

Who can take part

AI summary

From the trial's eligibility criteria. Machine-read from the registry text on this page, so it can be wrong. The registry text below and the trial team decide who can take part.

The trial is looking for teenagers and adults with cystic fibrosis who have abnormal glucose tolerance or early cystic fibrosis-related diabetes. It tests verapamil.

Age
14 years and older
Sex
All sexes can join.
Disease stage
Cystic fibrosis confirmed by genetic testing, with pancreatic insufficiency (needs pancreatic enzyme replacement therapy). Abnormal glucose tolerance or cystic fibrosis-related diabetes diagnosed within 3 months before enrolment.
Earlier treatment
People taking elexacaftor/tezacaftor/ivacaftor (ETI) must be willing to adjust the dose. Must not currently use insulin, a GLP-1 receptor agonist or an oral anti-diabetic medicine.
Biomarker or test result
Genetically confirmed cystic fibrosis. Abnormal glucose tolerance means an OGTT 2-hour glucose above 140 mg/dL (7.8 mmol/L) and below 200 mg/dL (11.1 mmol/L), or an OGTT 1-hour glucose above 200 mg/dL (11.1 mmol/L). Diabetes means a fasting glucose above 126 mg/dL (7 mmol/L) and/or an OGTT 2-hour glucose above 200 mg/dL (11.1 mmol/L).

Main reasons for not taking part

  • Severe lung disease (FEV1 below 50% predicted)
  • Current or planned pregnancy within the next 6 months
  • Most recent HbA1c above 7% (53 mmol/mol)
  • Significant heart disease, certain heart rhythm problems, or low blood pressure or heart rate
  • Weight below 50 kg (110 lb) or BMI below 18 kg/m2

The registry criteria, word for word

Show all 28 criteriaShow less

Who can take part

  • Age 14 years and older
  • Genetically-confirmed diagnosis of cystic fibrosis
  • Clinical diagnosis of pancreatic insufficiency, defined as requiring pancreatic enzyme replacement therapy (PERT)
  • Diagnosis of AGT or CFRD within 3-months of study enrollment; AGT is defined as having either a OGTT 2-hour glucose >140 mg/dL and <200 mg/dL or OGTT 1-hour glucose >200 mg/dL; CFRD is defined as having a fasting glucose >126 mg/dL and/or OGTT 2-hour glucose >200 mg/dL
  • Willing to attempt to maximize verapamil to the goal study dosage of 360 mg PO daily
  • If taking elexacaftor/tezacaftor/ivacaftor (ETI), willing to adjust dosing

Who cannot take part

  • Treatment with IV antibiotics for a CF exacerbation within 1 month
  • History of previously diagnosed vasovagal syncopal episodes related to hypotension
  • Need for the use of any pertinent medications (beta blockers, carbamazepine, phenobarbital, phenytoin, HMG-CoA reductase inhibitors, lithium, theophylline, clonidine)
  • Severe lung disease indicated by forced expiratory volume in 1 second (FEV1) <50% predicted on most recent spirometry testing
  • Known hypersensitivity to verapamil
  • History of significant cardiac disease (e.g. severe ventricular dysfunction, hypertrophic cardiomyopathy)
  • History of certain arrhythmias (e.g. AV block, accessory pathway such as Wolff-Parkinson-White or Lown-Ganong-Levine syndromes)
  • End stage renal disease on dialysis
  • History of Duchenne's muscular dystrophy
  • Allergy to any of the components of the MMTT standardized meal
  • Most recent HbA1c >7%
  • Abnormal liver function tests defined as AST or ALT >1.5 upper limit of normal [ULN] at the time of screening, or end stage cirrhosis
  • Blood pressure (BP) <90/60 (adults) or <5th centile for age and gender (youth) in 2 out of 3 measurements
  • Heart rate (HR) <60 bpm (adults) or <2nd centile for age and gender (youth) in 2 out of 3 measurements
  • Body mass index (BMI) <18 kg/m2
  • Weight <50 kg
  • Current or planned pregnancy within the next 6 months
  • Systemic supraphysiologic glucocorticoid use within 1 month
  • Initiation or discontinuation of a CFTR modulator within 3 months (i.e. recent change in CFTR modulator formulation/usage)
  • Current use of insulin, a GLP-1 receptor agonist, or oral anti-diabetic agent
  • Not taking a CFTR modulator due to genotype-ineligibility
  • Current use of vanzacaftor/tezacaftor/deutivcaftor

Where in United States

  • Diabetes Research Center, Massachusetts General HospitalBoston, United StatesContact: Melissa PutmanNot yet recruiting
  • Rhode Island HospitalProvidence, United StatesContact: Kevin J ScullyNot yet recruiting

About the trial

What the trial wants to find out

The investigators are conducting a pilot open-label pre/post interventional trial in adolescents and adults with cystic fibrosis (CF) and abnormal glucose tolerance or early CF-related diabetes mellitus (CFRD) to assess the safety and efficacy of verapamil on beta cell function and dysglycemia.

The group in the trial

  • Intervention ArmTreatment being tested

    verapamil hydrochloride

    Treatment: Verapamil Hydrochloride

Questions to ask the study team

  1. How often do I need to come in, and for how long each time?
  2. Are travel costs paid?
  3. Can I keep my own doctor?
  4. What happens if I want to stop?

Contact the study team: see the registry record → Contacts and Locations

Print a page for my doctor

Data and sources

Registry record
Listed on ClinicalTrials.gov.
Official title
The Effect of Verapamil on Beta Cell Function in Adolescents and Adults With Cystic Fibrosis-related Dysglycemia
Plain-language title
Verapamil for Blood Sugar Problems in Teens and Adults With Cystic FibrosisGenerated from the registry record. The registry title is the official one.
AI summary
From the trial's eligibility criteria. Read by machine on 12 November 2026.
Record updated
9 July 2026