Compared to placebo, treatment with ChAgly CD3 has a beneficial effect on preservation of beta cell function and metabolic outcome in type 1 diabetic patients with recent clinical onset of disease that persists until 48 months after administration.

The investigators also hypothesize that in type 1 diabetic patients with recent clinical onset of disease compared to placebo, ChAgly CD3 will be safe and well tolerated between 18 and 48 months after administration, based on assessment of clinical and laboratory adverse events.

Inclusion Criteria:

• Subjects with Type 1 diabetes mellitus included in the phase II therapeutic trial with a humanized non-mitogenic CD3 monoclonal antibody (ChAgly CD3) at time of clinical diagnosis and who agree and are likely to comply with the investigator's instructions

Exclusion Criteria:

• Any illness that, in the opinion of the investigator, might confound the results of the study or pose additional risks to the patient
• Use of illicit drugs or over consumption of alcohol (> 3 beers/day)
• Being legally incapacitated, having significant emotional problems at the time of the study