Oral insulin trial marks milestone toward personalized prevention of type 1 diabetes

The Primary Oral Insulin Trial (POInT) investigates whether type 1 diabetes in at-risk children can be prevented through oral insulin treatment. First results mark an important step toward the prevention of type 1 diabetes, pointing future efforts to personalized strategies. The group led by researchers from Helmholtz Munich and the Technical University of Munich (TUM) found that oral insulin treatment affects subgroups differently depending on their insulin gene variant.

POInT is the first randomized, controlled clinical trial to test whether daily oral insulin treatment could delay or prevent the development of islet autoantibodies—which are associated with the development of type 1 diabetes—in children at increased genetic risk of the condition.

Conducted across five European countries beginning in 2017, this unprecedented collaboration conducted by the Global Platform for the Prevention of Autoimmune Diabetes (GPPAD) involved 1,050 children in five European countries. The trial unites more than 30 years of genetic and immunological research and stands as one of the largest early prevention efforts in autoimmunity to date. The findings are published in The Lancet.

No impact on the overall development of islet autoantibodies

The researchers report that daily intake of insulin powder was well tolerated by the study population. However, oral insulin intake did not influence the overall development of islet autoantibodies during the study period.

Although this means that the primary trial outcome was negative, the exploratory analyses revealed promising secondary findings: children who received oral insulin showed delayed progression to clinical type 1 diabetes compared to those in the placebo group. Notably, the treatment’s effect varied depending on the child’s specific insulin gene variant—pointing to new possibilities for genetically tailored prevention strategies.

Therapy may positively influence the course of the disease

“The POInT study will change how we approach antigen-based therapies in type 1 diabetes. While the oral insulin therapy could not prevent the development of islet autoantibodies as we had hoped, the trial data suggest that this therapy may positively influence the course of the disease,” says Prof. Anette-Gabriele Ziegler, lead researcher of the study, Chair of Diabetes and Gestational Diabetes at the TUM University Hospital, and the director of the Helmholtz Munich Institute of Diabetes Research.

“First, we saw a delay in the progression to clinical disease in those who had received oral insulin, which is already a positive message. Second, a striking finding was how the treatment effect varied depending upon the genetics of the child. In particular, among children with type 1 diabetes risk variants of the insulin gene, a delay in the onset of type 1 diabetes appears possible, opening the door to targeted, personalized prevention of type 1 diabetes,” Prof. Ziegler explains.

“As POInT brings together decades of pioneering work on understanding and preventing type 1 diabetes, the study represents a major scientific milestone and is also closely connected to my personal mission: a world without type 1 diabetes.”

Outcome dependent on personal insulin gene variant

The gene encoding for the insulin protein naturally occurs in different variants. “Over half of the participants had variants that increase the risk for type 1 diabetes,” explains Ezio Bonifacio, member of the GPPAD study group and Professor at the Center for Regenerative Therapies at the TU Dresden. “In these children, oral insulin treatment protected against the development of diabetes. In contrast, among those with the non-risk variants, we observed an increase in the development of islet autoantibodies in the group treated with oral insulin.”

These findings suggest that oral insulin treatment might be beneficial for a genetically defined subgroup of children. “Although the underlying mechanism remains unclear, the results offer grounds for cautious optimism: with the right selection of those to treat, it may in the future be possible to decisively alter the course of the disease,” Bonifacio adds.

Advancing personalized prevention strategies

Building upon the initial findings, the POInT study will continue with an extended follow-up until participants reach the age of 12. Roughly 10% of the participating children developed islet autoantibodies by the age of 6, and the majority of these will develop clinical type 1 diabetes. The extended monitoring allows researchers to assess the longer-term effects of early oral insulin treatment and provides continued care for participating children. In addition, biological samples and data collected during the trial will be used in ancillary research projects.

These studies aim to uncover how oral insulin may modify the autoimmune reaction and influence the course of the disease. Ultimately, this will help to understand the early biological mechanisms that lead to type 1 diabetes. This way, the researchers hope to identify pharmacogenetic mechanisms that could enable personalized prevention of type 1 diabetes. To this end, the trial POInT cohort is especially relevant, as it is the first primary prevention trial to recruit children at risk from the general population.