Treatment of recent-onset type 1 diabetic patients with DiaPep277: Results of a double-blind, placebo-controlled, randomized phase 3 trial

OBJECTIVE: To evaluate safety and efficacy of DiaPep277 in preserving β-cell function in type 1 diabetic patients. RESEARCH DESIGN AND METHODS: DIA-AID 1 is a multinational, phase 3, balanced-randomized, double-blind, placebo-controlled, parallel-group clinical study. Newly diagnosed patients (N = 457, aged 16-45 years) were randomized to subcutaneous injections of DiaPep277 or placebo quarterly for 2 years. The primary efficacy end point was the change from baseline in the area under the glucagon-stimulated C-peptide curve. Secondary end points were the change from baseline in mixed-meal stimulated C-peptide secretion and in fasting C-peptide and achieving target HbA _1c ≤7% (≤53 mmol/mol). Partial remission (target HbA _1c on insulin ≤0.5 units/kg/day) and hypoglycemic event rate were exploratory end points. RESULTS: DiaPep277 was safe and well tolerated. Significant preservation of C-peptide secretion was observed in the DiaPep277-treated group compared with the placebo (relative treatment effects of 23.4%, P = 0.037, and 29.2%, P = 0.011, in the modified intent-to-treat [mITT] and per-protocol [PP] populations, respectively). The mixed-meal stimulation failed to distinguish between the groups. There was a trend toward efficacy in fasting C-peptide levels, though not statistically significant. Significantly more DiaPep277-treated than placebo-treated patients maintained target HbA _1c (mITT 56% versus 44%, P = 0.03; PP 60% versus 45%, P = 0.0082) and entered partial remission (mITT 38% versus 29%, P = 0.08; PP 42% versus 30%, P = 0.035). DiaPep277 treatment reduced the relative hypoglycemic event risk (mITT by 20%; PP by 28%). CONCLUSIONS: DiaPep277 safely contributes to preservation of β-cell function and to improved glycemic control in patients with type 1 diabetes.