Diabetes Research Centre

Melbourne, Australia

What is Diabetes?

Clinical Trials

In the Lab

Links

Contacts

Site History

INIT II (Intranasal Insulin) Trial

What is type 1 diabetes?
Type 1 diabetes is a condition in which the immune system reacts against the insulin-producing beta cells in the pancreas, eventually destroying the beta cells and causing a lack of insulin. Without the hormone insulin, the cells of the body are unable to use glucose and the level of glucose in the blood increases and causes symptoms of diabetes.

What is the aim of the trial?
The aim of the trial is to determine if exposure of the immune system in the mucus membranes to insulin, by treatment with intranasal insulin, will stop the immune reaction and further loss of b cells. This could prevent diabetes and the need for insulin injections. The intranasal insulin acts only on the mucus membranes and is not absorbed into the body. Insulin given this way does not affect blood glucose and will not cause hypoglycaemia (“hypos”).

Why intranasal insulin?
Research on mice that develop type 1 diabetes shows that exposure of the mucus membranes to insulin by treatment with intranasal insulin acts like a vaccine to induce protective immune cells that counteract the “bad” immune cells that damage the beta cells. In a recently-completed trial in children and young adults at risk type for type 1 diabetes, insulin given via a nasal spray was found to be safe and to cause immune changes similar to those in the mice that were protected from getting diabetes. It is now important to prove that along with these immune changes we can preserve b-cell function and stop progression to diabetes.

Who is eligible to participate in the trial?
Those eligible should: 1) have a first-degree relative (mother, father, brother or sister) or second-degree relative (uncle, aunt or cousin) with type 1 diabetes, 2) be aged between 4 and 30, and 3) have a positive blood test for antibodies to insulin and other components of the beta cell, which indicates that the immune attack on the beta cells is occurring and that there is a high risk for type 1 diabetes. All tests, treatment and care in the trial will be performed free of charge by the researchers conducting the trial.

What is involved?
The trial will involve treatment for 1 year, and then follow-up until the results are clear. Participants will be coded randomly to receive treatment with either intranasal insulin or an inactive solution. Insulin will be administered by a nasal spray, initially daily for 7 days and then on each weekend day for 1 year. Neither the participants nor the researchers will know the code until the trial is over.

At the start, and every 3 months for 2 years, participants will have a blood test for immune cells and antibodies; every 6 months they will have a blood test for their ability to make insulin. After 2 years, they will have the blood tests every 6 months, if necessary, until the results of the trial are clear.

Blood for the tests will be taken from a vein in the arm, as for routine diagnostic tests. Anaesthetic cream (“EMLAR”) will be provided to parents to apply to their child’s arm before the test. A volume of 20 ml (1 tablespoon), or a smaller volume for children less than 9 years of age, will be taken for the immune cell and antibody tests. The ability to make insulin will be determined by a test called an oral glucose tolerance test (OGTT) and also by a test called an intravenous tolerance test (IVGTT), on separate mornings after an overnight fast (no breakfast). After taking a blood sample of 5 ml (1 teaspoon) from the arm vein, a solution of glucose is either drunk (OGGT) or injected into the vein (IVGTT) and further 5 ml samples are taken 30, 60, 90 and 120 minutes later (OGTT) or 1, 3 and 5 minutes later (IVGTT) for measurement of insulin levels. The amount of blood taken for the tests is not excessive and the tests pose no risks beyond those associated with taking blood for routine diagnostic tests, the main one being the very small risk of introducing an infection.

If diabetes develops during the trial, participants would have to withdraw from the trial. In this case, the research doctors would arrange for proper care and management.

How will the results be assessed?
Tests of immune cells and antibodies will indicate if intranasal insulin has induced a protective immune response. The OGTT and IVGTT will indicate if intranasal insulin treatment prevents loss of beta-cell function.

The results will be analysed by an independent statistician at the end of the second year and, if necessary, at the end of each subsequent year, until the results of the trial are clear. On the basis of previous research, we estimate that an effect of intranasal insulin to preserve beta-cell function could be detected as early as two years after the start of the trial.

If intranasal insulin is found to prevent loss of beta-cell function all participants will be offered ongoing treatment after the trial. Because intranasal insulin acts like a vaccine, if it worked it would then not have to be given every week to maintain an effect.

What should you do if you are interested in participating?

If you are interested in participating you would first need to have the blood test for antibodies to determine if you were at high risk. This test is positive in only about 3% of relatives of someone with type 1 diabetes. To arrange the test, or for further information, please visit our
screening website at https://studies.thegeorgeinstitute.org/init/ , or call our call centre on 1300 138 712.

Return to INIT II Page

Return to Clinical Trials Page