Sanofi’s Tzield (teplizumab-mzwv) has received US FDA accelerated approval for a new indication as the first disease-modifying therapy for children aged 8 to 17 years recently diagnosed with stage 3 type 1 diabetes (T1D). Tzield hence moves beyond disease delay and into disease modification immediately after first diagnosis, potentially creating a new treatment window during which residual beta-cell function can be preserved rather than simply replaced with exogenous insulin.
Granted under the accelerated pathway, the indication covers delay of the decline in endogenous insulin production in this pediatric population and is restricted to autoimmune T1D. The label explicitly states Tzield is not effective in non-autoimmune dysglycemic conditions. Tzield was first approved in November 2022 for stage 2 T1D, and the FDA expanded that label in April 2026 to include children aged one year and older. The stage 3 indication now extends the drug’s reach to patients who have already crossed the clinical threshold of hyperglycemia and are managing active disease.
As an accelerated approval, Sanofi supplied data on a surrogate endpoint — reduced C-peptide decline. Preservation of C-peptide is generally associated with improved endogenous insulin production and has historically correlated with better glycemic control and lower insulin requirements. The French giant will need to provide confirmatory evidence from the BETA-PRESERVE Phase III study (NCT07088068), which is currently enrolling.
The supporting evidence came from PROTECT, a Phase III randomized, double-blind, placebo-controlled multinational study enrolling 328 children and adolescents aged 8 to 17 years diagnosed with stage 3 T1D within the preceding six weeks. Participants received two courses of 12 daily intravenous infusions — one at baseline and a second at approximately 26 weeks — at a 2:1 randomization ratio of Tzield to placebo, alongside standard-of-care insulin therapy. The primary endpoint assessed beta-cell function via mean C-peptide levels measured by area under the curve following a four-hour mixed-meal tolerance test. At trial completion, the Tzield arm demonstrated statistically significant slowing of C-peptide decline compared to placebo (difference in least-squares means: 0.13 pmol/mL; 95% CI: 0.09–0.17; p < 0.001). The broader clinical development program included data from over 900 patients who received teplizumab.
The safety profile was consistent with prior studies. Common adverse reactions included lymphopenia, vomiting, rash, leukopenia, diarrhea, neutropenia, elevated liver transaminases, and headache. Serious events — including cytokine release syndrome and life-threatening viral reactivation — have been reported, with immunocompromised patients at elevated risk.