Type1 DiabetesCLVerExNCT06177691
Hybrid Closed Loop Therapy and Verapamil for Beta Cell Preservation in New Onset Type 1 Diabetes (CLVer): Extension Study
An observational study of Type1 Diabetes, run by Jaeb Center for Health Research at 6 sites in United States.
Trial summary
The purpose of this extension study is to continue to follow the participants who completed the CLVer RCT for up to 3 additional years. The goal for Cohort A is to evaluate the longer-term effects of verapamil on preservation of β-cell function as measured by C-peptide levels obtained during a mixed meal tolerance… Read more about this study
- Who is it for?
- Ages 7 to 17 years
- Conditions the study is for
- Type1 Diabetes
- How many people
- 77 participants
- Where
- 6 sitesUnited States
- Study dates
- 7 May 2021to 31 Mar 2026
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 7 to 17 years
- All sexes
- No healthy volunteers
- Child
Study population: Participants who complete the CLVer RCT 12 month visit. RCT participants were youth aged 7-<18 years at RCT screening with newly diagnosed stage 3 type 1 diabetes.
Completed CLVer RCT 12 month visit and willing to join observational extension.
Trial locations and contacts
6 sites in 1 country.
6 sites in 1 country
United States6 sites
Barbara Davis Center
Aurora, Colorado, 80045
Indiana University
Indianapolis, Indiana, 46202
Children's Mercy Hospital
Kansas City, Missouri, 64111
University of Minnesota
Minneapolis, Minnesota, 55455
Yale University
New Haven, Connecticut, 06511
Stanford University
Palo Alto, California, 94304
About this study
The purpose of this extension study is to continue to follow the participants who completed the CLVer RCT for up to 3 additional years. The goal for Cohort A is to evaluate the longer-term effects of verapamil on preservation of β-cell function as measured by C-peptide levels obtained during a mixed meal tolerance test (MMTT). For both Cohorts A and B, the goal is to determine if the high degree of glycemic control achieved during CLVer with HCL can be maintained once the intensive engagement of the study team is discontinued. At the completion of the RCT, study treatments end. Thus, during the extension study, diabetes management is performed as part of usual care and there is no study treatment.
Read the detailed description
Participants who complete the CLVer RCT will be eligible to enroll in the CLVer Extension Study. Informed consent and assent, when applicable, will be obtained. Participants will be contacted every 3 months at which time continuous glucose monitoring (CGM) data will be obtained if a CGM device is being used and medical history (including recent point-of-care or local laboratory HbA1c values) will be reviewed; a usual care visit performed by study staff may be considered a study contact. A study visit will occur yearly to update the diabetes and medical history, measure height and weight, determine Tanner staging, download CGM data if available, perform an MMTT, and obtain blood samples for central lab measurement of HbA1c and plasma for storage if consented. Other than the central lab samples, there are no study-specific procedures or data collection that would not be performed as part of standard care.
- Conditions
- Type1 Diabetes
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Cohort A | Participants with body weight ≥30 kg (Cohort A) were randomly assigned in a factorial design during the RCT to (1) HCL plus intensive diabetes management or usual care with no HCL and (2) verapamil or placebo. No interventions were administered during the observational extension. | |
| Cohort B | Participants with body weight <30 kg (Cohort B) were randomly assigned during the RCT 2:1 in a parallel group design to HCL plus intensive diabetes management or to usual care with no HCL. No interventions were administered during the observational extension. |
What is being measured
The primary outcome is the main question the study is designed to answer.
C-peptide
The primary outcome is the C-peptide measured during the MMTT annually. This is measured as the area under the stimulated C-peptide curve (AUC). AUC is computed using a trapezoidal rule, which is a weighted sum of the C-peptide values over the 120 min. Peak C-peptide also will be computed.
Measured: Randomization, 13, 26, 39 weeks, Year 1, Year 2, Year 3, Year 4
Secondary outcomes (5)
HbA1c
HbA1c outcomes, measured annually, will include the following:
- Mean HbA1c
- Percentage of participants with an HbA1c <7.5%, <7.0% and <6.5%
Measured: Randomization, 13, 26, 39 weeks, Year 1, Year 2, Year 3, Year 4
CGM Metrics
CGM metrics will be computed for each time point of data collection. CGM-derived indices will be computed for 24 hours, daytime (6AM to midnight) and nighttime (midnight to 6AM). The Statistical Analysis Plan (SAP) will describe how CGM derived indices will be calculated. The following metrics will be computed:
- Mean glucose
- Percentage of sensor glucose from 70 to 180 mg/dL
- Percentage of sensor glucose >180 and >250 mg/dL
- Percentage of sensor glucose <54 and <70 mg/dL
- Coefficient of variation
Measured: 6, 13, 26, 39 weeks, Year 1, Year 2, Year 3, Year 4
Severe hypoglycemia episodes
Frequency of episodes of severe hypoglycemia by cohort group.
Measured: Year 4
Diabetic ketoacidosis events
Frequency of episodes of diabetic ketoacidosis by cohort group.
Measured: Year 4
Hospitalizations
Frequency of hospitalizations by cohort group.
Measured: Year 4
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted20 Dec 2023
- Study start7 May 2021
- Primary completion31 Mar 2026
- Study completion31 Mar 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Type1 DiabetesStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 77 participants (actual)
Sponsor and investigators
- Lead sponsor
- Jaeb Center for Health Research
- Sponsor type
- University, hospital or other
- Collaborators
- Juvenile Diabetes Research Foundation, University of Minnesota
- Responsible party
- Sponsor
- Investigators
- Antoinette Moran, MD, Study chair, University of MinnesotaGregory Forlenza, MD, Study chair, Barbara Davis Center
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06177691
- Sponsor's protocol ID
- CLVerEx
- Acronym
- CLVerEx
- Status last verified
- Sep 2026
- First submitted
- 11 Dec 2023
- Last updated
- 24 Sep 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 24 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Hybrid Closed Loop Therapy and Verapamil for Beta Cell Preservation in New Onset Type 1 Diabetes (CLVer): Extension Study
- ClinicalTrials.gov ID
- NCT06177691
- Acronym / sponsor ID
- CLVerEx / CLVerEx
- Conditions
- Type1 Diabetes
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 77 participants (actual)
- Lead sponsor
- Jaeb Center for Health ResearchUniversity, hospital or other
- Collaborators
- Juvenile Diabetes Research Foundation, University of Minnesota
- Study start
- 7 May 2021 (actual)
- Primary completion
- 31 Mar 2026 (actual)
- Study completion
- 31 Mar 2026 (actual)
- First posted
- 20 Dec 2023 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The purpose of this extension study is to continue to follow the participants who completed the CLVer RCT for up to 3 additional years. The goal for Cohort A is to evaluate the longer-term effects of verapamil on preservation of β-cell function as measured by C-peptide levels obtained during a mixed meal tolerance test (MMTT). For both Cohorts A and B, the goal is to determine if the high degree of glycemic control achieved during CLVer with HCL can be maintained once the intensive engagement of the study team is discontinued. At the completion of the RCT, study treatments end. Thus, during the extension study, diabetes management is performed as part of usual care and there is no study treatment.
Detailed description
Participants who complete the CLVer RCT will be eligible to enroll in the CLVer Extension Study. Informed consent and assent, when applicable, will be obtained. Participants will be contacted every 3 months at which time continuous glucose monitoring (CGM) data will be obtained if a CGM device is being used and medical history (including recent point-of-care or local laboratory HbA1c values) will be reviewed; a usual care visit performed by study staff may be considered a study contact. A study visit will occur yearly to update the diabetes and medical history, measure height and weight, determine Tanner staging, download CGM data if available, perform an MMTT, and obtain blood samples for central lab measurement of HbA1c and plasma for storage if consented. Other than the central lab samples, there are no study-specific procedures or data collection that would not be performed as part of standard care.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Cohort A | – | –Participants with body weight ≥30 kg (Cohort A) were randomly assigned in a factorial design during the RCT to (1) HCL plus intensive diabetes management or usual care with no HCL and (2) verapamil or placebo. No interventions were administered during the observational extension. |
| Cohort B | – | –Participants with body weight <30 kg (Cohort B) were randomly assigned during the RCT 2:1 in a parallel group design to HCL plus intensive diabetes management or to usual care with no HCL. No interventions were administered during the observational extension. |
Who may qualify
- Ages
- 7 to 17 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child
- Study population
- Participants who complete the CLVer RCT 12 month visit. RCT participants were youth aged 7-<18 years at RCT screening with newly diagnosed stage 3 type 1 diabetes.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
C-peptide
Time frame: Randomization, 13, 26, 39 weeks, Year 1, Year 2, Year 3, Year 4
The primary outcome is the C-peptide measured during the MMTT annually. This is measured as the area under the stimulated C-peptide curve (AUC). AUC is computed using a trapezoidal rule, which is a weighted sum of the C-peptide values over the 120 min. Peak C-peptide also will be computed.
5 secondary outcomes
HbA1c
Time frame: Randomization, 13, 26, 39 weeks, Year 1, Year 2, Year 3, Year 4
CGM Metrics
Time frame: 6, 13, 26, 39 weeks, Year 1, Year 2, Year 3, Year 4
Severe hypoglycemia episodes
Time frame: Year 4
Diabetic ketoacidosis events
Time frame: Year 4
Hospitalizations
Time frame: Year 4
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 24 Sep 2026.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Antoinette Moran, MD study chair
University of Minnesota
Gregory Forlenza, MD study chair
Barbara Davis Center
6 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Type1 Diabetes, run by Jaeb Center for Health Research at 6 sites in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 24 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 6 sites in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
C-peptide (time frame: Randomization, 13, 26, 39 weeks, Year 1, Year 2, Year 3, Year 4). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 24 Sep 2026.