Precision Administration of Anti-thymocyte Globulin With or Without Verapamil

November 20, 2025 updated by: University of Florida

Precision Administration of Anti-thymocyte Globulin With or Without Verapamil in Adolescents and Young Adults With Type 1 Diabetes

T cell directed therapy, anti-thymocyte globulin (ATG), in low doses, has been shown to lower HbA1c and preserve endogenous insulin production (measured by C-peptide) in individuals with recently diagnosed type 1 diabetes (T1D). However, not all individuals who received ATG responded to the therapy (i.e., non-responders). Additionally, use of ATG alone does not address inherent beta cell stress. A calcium channel blocker, verapamil, has demonstrated C-peptide preservation in newly diagnosed T1D. Investigators will identify those mostly likely to respond to ATG using an ex vivo predictive biomarker of response to ATG. In addition, Investigators will use sequential therapies to increase efficacy (ATG followed by verapamil) and explore synergistic mechanisms. This will be assessing with in depth immunophenotyping and quantify biomarkers of beta cell stress, cell death, and abnormal prohormone processing. Finally, novel clinical trial endpoints will be assessed for their ability to predict treatment efficacy earlier than the standard endpoint at 1 year.

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

Investigators will conduct a phase 2 1:1 randomized controlled and blinded trial in Aim 1 comparing stimulated C-peptide (and other measures) between those treated with low-dose ATG and those treated with placebo. Co-primary endpoints include the difference between mean ATG and placebo values of the 2-hr mixed meal tolerance test (MMTT)-stimulated area under the curve (AUC) C-peptide at 12 months (standard T1D trial measure) and the difference between the change in the same measure over the first 6 months. Participants will be stratified based on their ex vivo immune responder signature to allow an equal number of "responders" and "non-responders" in both treatment arms. Following each participant's completion of this 1 year randomized controlled trial (RCT) they will enter Aim 2 and be re-randomized to received verapamil or not in an open-label 1 year extension where mechanistic endpoints will be explored related to immunophenotyping, gene expression, DNA methylation and beta cell markers including markers of beta cell stress and death as well as markers of abnormal prohormone processing.

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.
60

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 Locations

  • United States
    • Colorado
      • Aurora, Colorado, United States, 80045
    • Florida
      • Gainesville, Florida, United States, 32610
        • Recruiting
        • University of Florida
        • Contact:
        • Principal Investigator:
          • Laura M Jacobsen, MD

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

  • Child
  • Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. Must be >= 6 years <= 35
  2. Must have a diagnosis of T1D for less than 100 days at randomization
  3. Willing to provide Informed Consent or have a parent or legal guardian provide informed consent if the subject is <18 years of age
  4. Positive for at least one islet cell autoantibody; GAD65A, mIAA, if obtained within 10 days of the onset of insulin therapy, IA-2A, ICA, or ZnT8A
  5. Must have stimulated C-peptide levels of 0.2 pmol/ml measured during a mixed meal tolerance test (MMTT) conducted at least 21 days from diagnosis of diabetes. Randomization should occur within one month (37 days) of the MMTT.
  6. Subjects who are EBV seronegative at screening must be EBV PCR negative within 30 days of randomization and may not have had signs or symptoms of an EBV compatible illness lasting longer than 7 days within 30 days of randomization
  7. Be at least 6 weeks from last live immunization
  8. Participants are required to receive killed influenza vaccination at least 2 weeks prior to randomization when vaccine for the current or upcoming flu season is available
  9. Be willing to forgo live vaccines during the treatment period and for 3 months following last dose of study drug
  10. Be willing to comply with intensive diabetes management

Exclusion Criteria:

  1. Be immunodeficient or have clinically significant chronic lymphopenia: (Leukopenia (< 3,000 leukocytes /μL), neutropenia (<1,500 neutrophils/μL), lymphopenia (<800 lymphocytes/μL), or thrombocytopenia (<100,000 platelets/μL).
  2. Have active signs or symptoms of acute infection at the time of randomization
  3. Have evidence of prior or current tuberculosis infection as assessed by PPD, interferon gamma release assay or by history
  4. Be currently pregnant or lactating, or anticipate getting pregnant within the two year study period
  5. Require use of other immunosuppressive agents including chronic use of systemic steroids
  6. Have evidence of current or past HIV, Hepatitis B or Hepatitis C infection
  7. Have any complicating medical issues or abnormal clinical laboratory results that may interfere with study conduct, or cause increased risk to include pre-existing cardiac disease, COPD, sickle cell disease, neurological, or blood count abnormalities
  8. Have a history of malignancies other than skin
  9. Evidence of liver dysfunction with AST or ALT greater than 3 times the upper limits of normal
  10. Evidence of renal dysfunction with creatinine greater than 1.5 times the upper limit of normal
  11. Vaccination with a live virus within the last 6 weeks
  12. Current or ongoing use of non-insulin pharmaceuticals that affect glycemic control within prior 7 days of screening
  13. Active participation in another T1D treatment study in the previous 30 days
  14. Prior treatment with any investigational agent to delay beta cell loss in T1D
  15. Known allergy to ATG or Verapamil
  16. Prior treatment with ATG, Verapamil or known allergy to rabbit derived products
  17. Any condition that in the investigator's opinion may adversely affect study participation or may compromise the study results

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: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Quadruple

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: Anti-thymocyte globulin (ATG) intravenous infusion
ATG (brand name Thymoglobulin) a polyclonal T cell antibody preparation. It will be given at low doses (0.5 mg/kg Day 1 then 2 mg/kg Day 2).
Drug: Anti-thymocyte globulin (ATG)
ATG (brand name Thymoglobulin) a polyclonal T cell antibody preparation. It will be given at low doses (0.5 mg/kg Day 1 then 2 mg/kg Day 2).
Other Names:
  • Thymoglobulin
Placebo Comparator: Placebo-ATG
Saline placebo
Drug: Placebo
I.V. Saline
Experimental: verapamil extended release capsule
Open label administration at 120, 240 or 360 mg daily based on weight and ECG findings
Drug: verapamil extended release capsule
Open label administration at 120, 240 or 360 mg daily based on weight and ECG findings
Other Names:
  • Calan
  • Isoptin

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
AUC C-peptide between ATG and placebo values
Time Frame: 12 Months
mean difference between ATG and placebo values of the 2-hr mixed meal tolerance test (MMTT)-stimulated area under the curve (AUC) C-peptide at 12 months
12 Months
Change in 2-hr MMTT AUC C-peptide
Time Frame: 6 months
mean difference between the change in 2-hr MMTT stimulated AUC C-peptide
6 months

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
Immune and beta cell mechanistic analyses
Time Frame: 6, 12, 18, 24 months
To explore mechanisms of synergy between ATG received in year 1 and the addition of open-label verapamil in year 2.
6, 12, 18, 24 months

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 Florida

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
University of Colorado, Denver
University of Miami

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: Laura M Jacobsen, MD, University of Florida

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

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.
November 12, 2025

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.
November 1, 2028

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.
August 1, 2030

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).
June 3, 2024

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.
June 6, 2024

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.
June 12, 2024

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.
November 26, 2025

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.
November 20, 2025

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.
November 1, 2025

More Information

Terms related to this study

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.
  • IRB202400422

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

resources generated by this proposal will be made available to the general scientific community through publication in peer-reviewed journals and presentation at national/international meetings. Genomic data in the form of transcriptomic, epigenomic, and gene expression data will be generated. This proposal includes < 60 human samples. Nonetheless, I will prepare the data for submission to appropriate public repositories. These include 1) the National Center for Biotechnology Information (NCBI, https://www.ncbi.nlm.nih.gov/) Gene Expression Omnibus (GEO, http://www.ncbi.nlm.nih.gov/geo) for functional genomic data, 2) Encyclopedia of DNA Elements (ENCODE) for transcriptional and epigenetic data, and 3) immuneACCESS (https://clients.adaptivebiotech.com/immuneaccess) for immune repertoire data. I will follow the standardization of these organizations to provide valuable data allowing for reproducible results following the FAIR principles (Findable, Accessible, Interoperable, Reusable).

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

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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