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Completed

NCT Number: NCT06177691

Hybrid Closed Loop Therapy and Verapamil for Beta Cell Preservation in New Onset Type 1 Diabetes (CLVer): Extension 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.

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Key information

Conditions

Type1 Diabetes

Age range

7 year–17 year

Sex eligibility

All sexes

Study type

Observational

Primary location

Stanford University, Palo Alto, California, United States

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About this study

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.

Who can participate

Healthy volunteers accepted: No

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

Completed CLVer RCT 12 month visit and willing to join observational extension.

Treatment and study plan

Primary outcomes

  1. 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.

Secondary outcomes

  1. HbA1c

    Time frame: Randomization, 13, 26, 39 weeks, Year 1, Year 2, Year 3, Year 4

    HbA1c outcomes, measured annually, will include the following:

    • Mean HbA1c
    • Percentage of participants with an HbA1c <7.5%, <7.0% and <6.5%

  2. CGM Metrics

    Time frame: 6, 13, 26, 39 weeks, Year 1, Year 2, Year 3, Year 4

    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

  3. Severe hypoglycemia episodes

    Time frame: Year 4

    Frequency of episodes of severe hypoglycemia by cohort group.

  4. Diabetic ketoacidosis events

    Time frame: Year 4

    Frequency of episodes of diabetic ketoacidosis by cohort group.

  5. Hospitalizations

    Time frame: Year 4

    Frequency of hospitalizations by cohort group.

Interested in participating?

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Sponsors and collaborators

Lead sponsor

Jaeb Center for Health Research

Other

Collaborators

  • Juvenile Diabetes Research Foundation
  • University of Minnesota

Registry information

Acronym: CLVerEx

Important dates

Study start
2021
Primary completion
2026
Study completion
2026
First posted
Dec 20, 2023
Registry last updated
Sep 24, 2026

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

View the official ClinicalTrials.gov record (opens in a new tab)

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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