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.
Plain-language title generated from the registry record
Registry title: Verapamil Effect in Cystic Fibrosis-related Dysglycemia
Key facts
- Where
- Boston and Providence, United StatesSee the 2 sites
- Phase
- Phase 2
AI summary: who the study is looking for
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
Read by machine on 9 November 2026.
Where in United States
- Diabetes Research Center, Massachusetts General HospitalBoston, United StatesNo longer taking part
- Rhode Island HospitalProvidence, United StatesNo longer taking part
Questions to ask the study team
- How often do I need to come in, and for how long each time?
- Are travel costs paid?
- Can I keep my own doctor?
- What happens if I want to stop?
Trial details
- Who runs it
- Rhode Island Hospital
- Trial code
- NCT07688070
- Record updated
- 9 July 2026
- Original description
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.Read full original descriptionShow less
The Effect of Verapamil on Beta Cell Function in Adolescents and Adults With Cystic Fibrosis-related Dysglycemia
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.
Inclusion: 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.
Exclusion: 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.