This is a multicenter, randomized, double-blind, parallel, placebo-controlled Phase 3, 2-arm study for treatment.
The purpose of this study is to measure change in glycemic control and prandial insulin independency over 52 weeks with teplizumab compared with placebo, both administered by intravenous (IV) infusion, in participants with recently diagnosed Stage 3 type 1 diabetes (T1D) aged 1 to 25 years, on standard insulin therapy.
Participant must be 1 to 25 years of age inclusive, at the time of signing the informed consent.
Participants diagnosed with T1D Stage 3 according to American Diabetes Association 2025 criteria
Participants able to be randomized and initiate study drug within 8 weeks (56 days) of the Stage 3 T1D diagnosis
Glutamic acid decarboxylase (GAD-65),
Participant has diabetes other than autoimmune T1D that includes but is not limited to genetic forms of diabetes, maturity-onset diabetes of the young (MODY), diabetes secondary to medications or surgery and type 2 diabetes by judgement of the Investigator.
Participant has an active serious infection and/or fever ≥38.5°C (101.3°F) within the 48 hours prior to the first dose (except if localized skin infection), or has chronic, recurrent or opportunistic infectious disease.
At screening, participant has laboratory or clinical evidence of acute or clinically active infection with Epstein-Barr virus (EBV), cytomegalovirus (CMV).
At screening, participant has positive serology for human immunodeficiency virus (HIV), hepatitis B (HBV), or hepatitis C (HCV).