FDA Accepts for Priority Review sBLA for Teplizumab for Children With Stage 2 T1D

Announced on January 5, 2026, by parent company Sanofi, the US Food and Drug Administration (FDA) has accepted for priority review the supplemental biologics license application (sBLA) for teplizumab-mzwv to expand the age indication from ≥8 years to ≥1 year, aiming to delay the onset of stage 3 type 1 diabetes (T1D).1

“This priority review emphasizes the urgen need for innovative therapies like [teplizumab] which has the potential to prevent the natural progression of T1D by delaying the loss of endogenous insulin production,” Christopher Corsico, global head of development at Sanofi, said in a statement. “This might be particularly significant in this young population, as it is well documented that the autoimmune attack that drives this disease in many cases begins early in life.”1

Teplizumab-mzwv is a CD3-directed monoclonal antibody, and the first and only disease-modifying therapy in autoimmune T1D. It initially received FDA approval in November 2022 to delay the onset of stage 3 T1D in adults and children ≥8 years diagnosed with stage 2 T1D.1

The sBLA submission was based on positive interim one-year data from the ongoing PETITE-T1D phase 4 study, a 2 year single-arm, open-label, multicenter study of children <8 years with stage 2 T1D. Participants enrolled in the trial were given a 14-day teplizumab course. Primary endpoints included treatment-emergent adverse events (TEAEs), TEAEs leading to discontinuation of treatment, and serious adverse events (SAEs). Secondary endpoints examined immunogenicity, pharmacokinetics, pharmacodynamics, and time from study treatment to stage 3 T1D.2

A total of 23 participants were enrolled in the trial, with a mean age of 4.8 years (range, 1.7-6.8). Median follow-up duration was 51.9 weeks. All 23 patients experienced ≥1 TEAE, with most being mild to moderate – no grade 4 or 5 TEAEs were reported. 3 participants (13%) had TEAEs leading to discontinuation, including anemia, elevated liver enzymes, and maculopapular rash. An additional 2 participants (9%) each had 2 SAEs.2

Serum teplizumab concentrations peaked at day 14, and 2 participants progressed to stage 3 T1D. Investigators estimated a probability of lack of progression to stage 3 of 89.6% (95% CI, 64.3-97.3%) at the time of interim analysis. The analysis was conducted after 15 patients had completed 1 year of follow-up, but it included all 23 enrolled patients.2

Ultimately, teplizumab was deemed safe and well-tolerated in children <8 years with stage 2 T1D. Adverse events were consistent with previous studies, and no new safety risks were identified. Although surveillance is still ongoing and the trial will not conclude for another year, the Company has submitted these interim data for the purpose of expanding teplizumab’s existing indication. However, the press release notes that the safety and efficacy of teplizumab in this trial have not been approved by any regulatory agency.1,2

According to the Company, the FDA has set a Prescription Drug User Fee Act (PDUFA) target action date of April 29, 2026.1

References

1. Sanofi. Press Release: Sanofi’s Tzield accepted for priority review in the US for young children with stage 2 type 1 diabetes. January 5, 2026. Accessed January 5, 2026. https://www.sanofi.com/en/media-room/press-releases/2026/2026-01-05-06-00-00-3212420

2. Gitelman SE, Simmons K, Sherr JL, et al. Safety and pharmacokinetics of teplizumab in children less than 8 years of age with stage 2 type 1 diabetes. Diabetologia. Published online November 6, 2025. doi:10.1007/s00125-025-06586-1