Statistical analysis
The safety analysis set comprised all 42 enrolled participants who received at least one AG019 dose. All repeat-dose participants in the AG019 monotherapy (Safety data were descriptively analysed based on the safety analysis set. ANOVA was used to compare demographic and baseline characteristics between all cohorts and between active and placebo groups in the AG019/teplizumab cohorts. PK data were descriptively analysed based on a subset of the ITT analysis set (no PK faecal samples were collected from low-dose monotherapy participants). All metabolic data analyses were based on the PP analysis set. The 2 h AUC of C-peptide from the MMTT was calculated using the linear trapezoidal rule over a 2 h period (0–120 min), and the C-peptide mean AUC was obtained by dividing the calculated AUC values by the time period (120 min). The 2 h mean C-peptide AUC was used to identify treatment responders post hoc according to published criteria [Details of study population, sample size, interim analysis, randomisation and blinding, and pharmacodynamic assessments are provided in the ESM 