Early Metabolic Endpoints Identify Persistent Treatment Efficacy in Recent-Onset Type 1 Diabetes Immunotherapy Trials

Area of Science:

• Immunology
• Endocrinology
• Clinical Trials

Background:

• Type 1 diabetes (T1D) trials often use 12-24 month C-peptide AUC to assess β-cell preservation.
• Earlier detection of treatment efficacy could optimize trial design and resource allocation.

Purpose of the Study:

• To investigate if early dynamic measures of C-peptide AUC can predict long-term outcomes in T1D immunotherapy trials.
• To determine if shorter trial durations are feasible for establishing treatment efficacy.

Main Methods:

• Post hoc analysis of six Type 1 Diabetes TrialNet immunotherapy trials.
• Examined dynamic C-peptide AUC changes at 3 and 6 months as predictors of 12-month outcomes.
• Partitioned trials into successful and unsuccessful based on primary endpoints.

Main Results:

• A significant treatment effect was detected at 3 and 6 months using dynamic C-peptide AUC in successful trials (P = 0.030 and P < 0.001).
• Dynamic C-peptide AUC at 6 months strongly predicted 12-month C-peptide AUC preservation (R2 = 0.80, P < 0.001).
• This approach supported the feasibility of smaller trial sizes, down to 54 participants.

Conclusions:

• Early dynamic C-peptide AUC measurements can identify treatment effects in successful T1D immunotherapy trials.
• These early markers offer good long-term predictive value and support shorter trial durations (6 months).
• External validation is needed, but findings support shortening early-phase clinical trials for T1D interventions.