Type 1 Diabetes Extension Study

This is a multi-center, prospective, non-interventional study that focuses on the long- term effects following participation in select Immune Tolerance Network (ITN) new-onset Type 1 Diabetes Mellitus (T1DM, T1D) interventional studies focusing on immunomodulatory agents. Participants include those that have completed participation in the following trials: ClinicalTrials.gov trials NCT00129259 (AbATE), NCT00965458 (T1DAL) and NCT02293837 (EXTEND) . This observational study will: - follow participants to determine how long they continue to produce insulin, and - will also assess how changes in the immune system over time relate to the ability to produce insulin. This information could help design better therapies for type 1 diabetes in the future.

Depending upon a participant's level of insulin production, participation may be as short as one return visit or a maximum of five years. Evaluation visits will include: - Overall health assessments - Blood and urine collections - Mixed meal tolerance test (MMTTs) for certain participants, per protocol.