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The FDA has accepted for priority review a supplemental biologics license application (sBLA) for teplizumab-mzwv (Tzield; Sanofi) that seeks to expand the current age indication from 8 years and older to include children as young as 1 year of age. If approved, the expanded indication would allow teplizumab-mzwv to be used to delay the onset of stage 3 type 1 diabetes (T1D) in pediatric patients diagnosed with stage 2 disease. The FDA has set a target action date of April 29, 2026.1
PETITE-T1D study of teplizumab-mzwv
The sBLA is supported by positive interim 1-year data from the ongoing PETITE-T1D (NCT05757713) phase 4 study, which is evaluating the safety and pharmacokinetics of teplizumab-mzwv in young children. Interim findings from the study were presented at the 51st Annual Conference of the International Society for Pediatric and Adolescent Diabetes and published simultaneously in Diabetologia.
The single-arm, non-randomized, open-label, multicenter study was designed to evaluate the safety and pharmacokinetics of teplizumab-mzwv in children under the age of 8 who have been diagnosed with stage 2 T1D. The study has enrolled 23 participants to date.
Participants receive an intravenous infusion of teplizumab-mzwv once daily for 14 consecutive days. Each individual may be followed for up to 26 months for safety monitoring and additional assessments. The interim 1-year data formed the basis of the sBLA submission and the FDA’s priority review decision.
Although detailed efficacy outcomes have not been approved for this population, the study aims to determine whether the earlier use of teplizumab-mzwv is feasible and appropriate in very young children with evidence of autoimmune beta-cell destruction, according to Sanofi.
Addressing early disease progression in type 1 diabetes
Stage 2 T1D is defined by the presence of 2 or more diabetes-related autoantibodies along with dysglycemia, prior to the onset of insulin dependence. In many individuals, the autoimmune process that ultimately leads to insulin deficiency begins in early childhood. Delaying progression to stage 3 disease may help preserve endogenous insulin production and reduce disease burden during critical developmental years.
Priority review designation is reserved for applications that have the potential to provide significant improvements in the treatment, diagnosis, or prevention of serious conditions. In this case, the FDA’s decision underscores the unmet need for disease-modifying therapies that intervene earlier in the T1D disease course, particularly in very young patients.
According to Sanofi, the safety and efficacy of teplizumab-mzwv in children younger than 8 years has not yet been approved by any regulatory authority, and the current application is based on interim data designed to support a potential label expansion.
Current regulatory status of teplizumab-mzwv
Teplizumab-mzwv is a CD3-directed monoclonal antibody and is currently the first and only disease-modifying therapy approved for autoimmune T1D. In the United States, it was initially approved in November 2022 to delay the onset of stage 3 T1D in adults and pediatric patients aged 8 years and older with stage 2 disease. The therapy has since received approvals in multiple international markets, including China, the United Kingdom, Canada, Israel, Saudi Arabia, the United Arab Emirates, and Kuwait.
In November 2025, the European Medicines Agency’s Committee for Medicinal Products for Human Use issued a positive recommendation for the same patient population, with additional regulatory reviews ongoing globally.
If approved, the proposed age expansion could further shift the treatment paradigm in T1D by enabling intervention at even earlier stages of autoimmune disease, potentially altering the trajectory of diabetes development in very young children.
