825-P: Composite Glucose and C-Peptide Endpoints Show Early Efficacy in Recent-Onset Type 1 Diabetes (T1D) Clinical Trials

C-peptide area under the curve (AUC) at ≥1 year, a standard endpoint of recent-onset T1D clinical trials, is derived from a 120-minute mixed meal tolerance test (MMTT) . We analyzed whether composite glucose and C-peptide endpoints, useful in post hoc analyses of prevention trials, could detect treatment effects as early as 3 months between the combined treated and placebo groups from 3 TrialNet recent-onset T1D trials that met their primary endpoint. Comparisons were made between treated and placebo groups after adjustments for age, sex, and BMI Z-score using AUC C-peptide (standard measure) , AUC C-peptide/AUC glucose (AUC ratio) , and a new measure, the centroid ratio. Centroids, geometric central points of shapes, were derived from MMTT shapes formed from mean glucose and C-peptide values at 30, 60, 90, and 120 minutes. The centroid ratio is the C-peptide coordinate/glucose coordinate of the centroid. A treatment effect at 3 months was evident for centroid and AUC ratios (p In conclusion, composite glucose and C-peptide endpoints appear to identify early treatment efficacy and should be considered in future new-onset pilot studies and trials. Disclosure L.M.Jacobsen: None. A.Pugliese: Advisory Panel; Provention Bio, Inc., Consultant; Quell Tx. P.Gottlieb: Advisory Panel; Janssen Research & Development, LLC, ViaCyte, Inc., Other Relationship; IM Therapeutics, Research Support; Caladrius Biosciences, Inc., Immune Tolerance Network, National Institute of Diabetes and Digestive and Kidney Diseases, Novo Nordisk, Precigen, Inc., Tolerion, Inc. J.Sosenko: None. D.D.Cuthbertson: None. M.J.Haller: Advisory Panel; SAB Biotherapeutics , Consultant; MannKind Corporation, Sanofi. H.M.Ismail: n/a. E.K.Sims: Other Relationship; Medscape, Patent. S.E.Gitelman: Advisory Panel; Abata Therapeutics, Avotres Inc., Biolojic Design, Ltd., Provention Bio, Inc., Rubius, SAB Biotherapeutics, Inc., Tolerion, Inc. D.K.Wherrett: n/a. A.Moran: Advisory Panel; Dompé, Other Relationship; Novo Nordisk, Research Support; Abbott Diabetes, Provention Bio, Inc. M.A.Atkinson: None.