This study looks at how well a medicine called teplizumab works for people with Stage 2 Type 1 Diabetes (T1D). T1D is a disease where the body can't make insulin, a hormone that helps control blood sugar. Stage 2 means it's early, and the goal is to delay Stage 3, where it gets worse. It's observational, meaning doctors will watch and gather information instead of giving a specific treatment plan. They’ll also see how teplizumab affects people’s feelings and daily lives.

• Participants will be monitored for up to 10 years.
• No new treatments will be given; it's just observation.
• The study is for people who have already started teplizumab, not new patients.

If you or your child have Stage 2 T1D and started teplizumab in the last 6 weeks, you might be able to join. You can't join if you've been in another teplizumab study or clinical trial in the last 6 months. This study helps us understand how teplizumab works over a long time for various people. Participation requires consent, meaning you agree to be part of the study.