FDA approves new indication for Sanofi’s Tzield to delay type 1 diabetes onset in children

Sanofi received US FDA approval for an expanded indication for Tzield (teplizumab-mzwv), extending the drug’s use to children as young as one year of age with stage 2 type 1 diabetes (T1D) to delay onset of stage 3 disease. The supplemental biologic license application was granted under priority review, making Tzield the first disease-modifying therapy available for this age group — a distinction the company said reflects the particular severity of T1D progression in very young children.

The approval expands the existing US indication, which has covered adults and children aged eight years and older since Tzield’s initial FDA approval in November 2022. That original clearance itself represented a first-in-class milestone: teplizumab-mzwv, a CD3-directed monoclonal antibody that modulates the autoimmune destruction of insulin-producing beta cells, was the first disease-modifying agent approved in autoimmune T1D. The new label extension lowers the eligible age threshold by seven years, reaching a population in which disease progression can be rapid and management particularly complex given the practical constraints of insulin delivery in infants and toddlers.

The indication covers patients with stage 2 T1D, defined by the presence of two or more T1D-related autoantibodies alongside dysglycemia, but without clinical symptoms. Stage 3 T1D — the point at which clinical hyperglycemia emerges and lifelong insulin dependence begins — represents the threshold the therapy is designed to delay. The treatment regimen consists of a 14-day course of once-daily intravenous infusion.

The FDA’s decision was supported by one-year data from PETITE-T1D, a Phase IV single-arm, open-label, multi-center study enrolling 23 children under eight years of age with stage 2 T1D. The study’s primary focus was safety and pharmacokinetics in this younger population rather than efficacy, reflecting a regulatory pathway that leveraged existing efficacy data from the adult and older pediatric population to extrapolate benefit, while requiring age-specific safety and drug exposure data. Each participant received the 14-consecutive-day IV infusion regimen, with a study duration of up to 26 months including screening and follow-up.

The clinical rationale for pursuing this age extension rests on the biology of T1D progression. Autoantibody seroconversion — the earliest detectable sign of the autoimmune process — frequently occurs in the first years of life, and younger children with multiple autoantibodies face a steeper trajectory toward clinical disease. Prior to this approval, no disease-modifying option existed for children diagnosed at stage 2 before age eight, leaving watchful waiting as the only approach.

For Sanofi, the approval consolidates a position it acquired through its approximately USD 2.9 billion acquisition of Provention Bio in 2023. Teplizumab’s development history stretches back further: originally discovered at the University of Chicago and later licensed to Eli Lilly, the program was suspended following a Phase III failure in 2010 before MacroGenics sold the asset to Provention Bio in 2018. Provention Bio secured the initial FDA approval in 2022, and Sanofi completed its acquisition the following year.

The drug is also under active FDA review for a separate indication — delaying progression of stage 3 T1D in patients aged eight years and older recently diagnosed with clinical disease — which, if approved, would extend teplizumab’s utility into the post-onset setting. Internationally, the therapy is approved in the EU under the name Teizeild, as well as in the UK, China, Canada, and several other markets, though the current expanded pediatric indication applies specifically to the US label.

The broader T1D disease-modification field remains at an early stage. Teplizumab’s mechanism — transient CD3-directed immunomodulation delivered as a short course — differs from longer-term immunosuppressive approaches and from emerging cell therapy strategies aimed at beta-cell replacement. The drug holds FDA orphan drug designation, reflecting the relatively small patient population with detectable stage 2 disease, and previously received breakthrough therapy designation. Identifying eligible patients depends on autoantibody screening, which is not yet standard practice across all pediatric populations, a factor that may affect the breadth of clinical uptake regardless of the approved age range.