TrialNet researchers are testing a low dose of the immunotherapy drug anti-thymocyte globulin (ATG) to see if it can delay or prevent type 1 diabetes (T1D) in people ages 6 to 34 who have a 50% risk of clinical diagnosis (Stage 3) within 2 years. Risk is defined by having two or more autoantibodies and abnormal blood sugar (Stage 2), plus at least one high-risk marker (based on test results).

In an earlier TrialNet study, low-dose ATG preserved insulin production and improved blood sugar control for 2 years in people newly diagnosed with T1D.

The STOP-T1D Prevention Study is the first to test ATG in people at high risk. In this study, two-thirds of participants will get the study drug and one-third will get a placebo (looks like the study drug but is inactive). A computer will randomly select who gets the study drug, and neither the participants nor the study staff will know who is in which group until the end of the study.

ATG is approved by the Food and Drug Administration (FDA) for preventing and treating kidney transplant rejection.

As with any medical intervention, there are risks and benefits to participating in this study. Before you join the study, a member of our research team will explain all potential risks and benefits and answer all your questions.

Who Can Participate

To find out if this study is right for you, the first step is to sign up for risk screening through the Pathway to Prevention Study. Screening detects diabetes-related autoantibodies that signal the early stages of T1D.

STOP-T1D Prevention Study participants are:

• between the ages of 6 and 34
• have a 50% risk of developing T1D within 2 years, as defined by having two or more diabetes-related autoantibodies and abnormal blood sugar levels (Stage 2), plus at least one of the following high-risk markers:
  • Hemoglobin A1C between 5.7 and 6.4%
    (a measure of average blood sugar levels over the past 3 months)
  • Index60 equal to or greater than 1.4
    (a measure of how much insulin the body is making on its own)
  • DPT Risk Score (DPTRS) equal to or greater than 7.4
    (a measure of risk based on blood sugar levels, age, BMI, and how much insulin the body is making on its own)
• up to date on required vaccines (inluding the flu vaccine when it is available)
• NOT pregnant or planning to become pregnant while participating in the study

Participant Experience

This study has a treatment phase and follow up visits.

Treatment (2 consecutive days)

In the treatment phase you will get two doses of the study treatment (ATG or placebo) by intravenous (IV) infusion over 2 consecutive days. Each infusion will take between 6 and 10 hours, followed by 2 hours of monitoring. You may need to stay overnight at the treatment center for observation.

Small sub-study (24 participants)

A small group of participants (12 that are 18 or older; 12 that are younger than 18) will be asked to participate in a sub-study. If you are included in this group, you will be asked to come back to the study site after the treatment period (days 2, 4 and 7) for additional blood samples. These samples will be used to study ATG’s activity in the body.

Follow up (at least 24 months)

In the follow up phase you will visit the study site for monitoring periodically for at least 24 months.

Continuous Glucose Monitor (CGM)

At certain times before and during the study you will need to wear a special continuous glucose monitor (CGM) provided by TrialNet. Unlike a typical CGM, this one won’t allow you, or anyone else, to see your personal blood sugar levels.

Ongoing Follow Up

As part of the TrialNet family, we’ll continue to follow you when this study is over. Your continued participation will be vital to helping us answer important questions about T1D prevention.

Benefits of monitoring

In addition to potentially delaying or preventing disease progression, benefits of participating in the study include close monitoring. If you develop T1D, our tests will likely show this before you have any symptoms.

For people taking part in T1D research, the risk of diabetic ketoacidosis (DKA) at diagnosis drops from 30% to 3%. DKA is a serious condition that can be life-threatening. With early notification, you’ll be able to see your doctor and start taking insulin before you feel sick.

This study will be available at TrialNet sites within the U.S. and internationally. For those willing to travel, assistance is available to help you get to the nearest location.