The TrialNet 10 Anti-CD3 Prevention (TN-10) trial previously showed delayed onset of stage 3 type 1 diabetes mellitus (T1DM) in individuals with stage 2 disease who had a relative with T1DM. A retrospective analysis published in Diabetes Care evaluated whether the progression risk observed in the TN-10 placebo group is comparable to that seen in a European population with or without first-degree relatives (FDRs) with T1DM.

The analysis included participants with stage 2 T1DM from the TN-10 placebo arm in the United States and Canada (n = 32) and from the German population-based Fr1da screening program (n = 152). The time to progression from stage 2 to stage 3 T1DM was assessed. The study had sufficient statistical power only to detect large differences between groups.

The risk of progression to stage 3 T1DM was comparable between the TN-10 placebo arm and the Fr1da group, with a hazard ratio (HR) of 1.3 (95% confidence interval [CI] 0.8 to 2.1). After inclusion of prognostic factors significantly associated with progression in this analysis, including anti-IA-2 antibodies, hemoglobin A1c (HbA1c) greater than 5.7%, and 120-minute oral glucose tolerance test results, the adjusted HR was 1.1 (95% CI 0.6 to 2.1). Within the Fr1da cohort, participants with FDRs (n = 45) and those without FDRs (n = 107) had similar time to progression to stage 3. Age-based subanalysis demonstrated minimal impact of age on progression time.

Overall, the time to progression from stage 2 to stage 3 T1DM appeared similar across cohorts and across family history groups in this analysis.