The purpose of this study is to assess the safety and pharmacokinetics (PK) of teplizumab in participants with Stage 2 type 1 diabetes who are <8 years of age.

This is a single-arm, non-randomized, open-label, multicenter study in the U.S. to assess the safety and pharmacokinetics of teplizumab in pediatric participants with Stage 2 type 1 diabetes (T1D) (two T1D-related autoantibodies and dysglycemia) who are 0 to <8 years of age. Anti-drug antibodies/neutralizing antibodies (ADA/NAb) will also be assessed.

Approximately 20 participants will be enrolled. The regimen consists of an intravenous infusion of teplizumab once daily for 14 consecutive days. The study duration for each individual may last up to approximately 26 months.

The safety, tolerability, PK, ADA, and T1D clinical feature data will be summarized using descriptive statistics.

Inclusion Criteria:

1. Participant is a male or female 0 to < 8 years of age, inclusive, at Day 1
2. Participant has Stage 2 T1D (two T1D-related autoantibodies and dysglycemia)

Exclusion Criteria:

1. Participant has any autoimmune disease other than T1D with the exception of stable thyroid or celiac disease
2. Has an active infection and/or fever
3. Has a history of or serologic evidence at screening of current or past infection with human immunodeficiency virus (HIV), hepatitis B virus (HBV), or hepatitis C virus (HCV).
4. Has any condition that, in the opinion of the Investigator, would interfere with the study conduct or the safety of the participant.

Qualified researchers may request access to patient level data and related study documents including the clinical study report, study protocol with any amendments, blank case report form, statistical analysis plan, and dataset specifications. Patient level data will be anonymized and study documents will be redacted to protect the privacy of trial participants. Further details on Sanofi's data sharing criteria, eligible studies, and process for requesting access can be found at: https://vivli.org