OBJECTIVE

Treatments have failed to delay or stop the autoimmune process, preceding onset of type 1 diabetes. We investigated if autoantigen-specific treatment with alum-formulated glutamate decarboxylase (GAD-Alum) was safe and affected progression to type 1 diabetes in children with islet autoimmunity.

METHODS

In an investigator-initiated, double-blind, placebo-controlled clinical trial, non-diabetic children aged 4 to 17.9 years with autoantibodies to glutamate decarboxylase (GADA) and at least one of insulinoma-associated protein 2, insulin or zinc-transporter 8, were randomized, stratified by 2 or ≥3 islet autoantibodies, to 2 injections of 20 μg GAD-Alum or placebo, 30 days apart. Main outcome was safety, investigated by adverse events, hematology, chemistry, thyroid and celiac autoimmunity and titers of islet autoantibodies, and efficacy, investigated by cumulative incidence of diabetes onset over 5-year follow-up. Secondary variables: change in first-phase insulin release (FPIR) after intravenous glucose tolerance tests, fasting, 120 minutes and Area under the curve (AUC) C-peptide and p-glucose after oral glucose tolerance tests and HbA1c.

RESULTS

Fifty children (median age: 5.2) were assigned 1:1 to GAD-Alum or placebo, all receiving full treatment and included in the analyses. GAD-Alum did not affect any safety parameter, while GADA titers increased (P = .001). Time to clinical diagnosis was not affected by treatment (hazard ratio, HR = 0.77, P = .574) in the full population or in the separate stratum groups. Treatment did not affect any of the secondary variables.

CONCLUSIONS

GAD-Alum as a subcutaneous prime and boost injection was safe in prediabetic young children but did not affect progression to type 1 diabetes. The safety of GAD-Alum should prove useful in future prevention studies.