FDA Expands Teplizumab-mzwv Approval to Young Children With Stage 2 T1D

The FDA has approved a supplemental biologic license application (sBLA) for teplizumab-mzwv (Tzield; Sanofi), expanding its approved indication to include children as young as 1 year of age with stage 2 type 1 diabetes (T1D).¹ The approval expands the previous indication—which covered patients 8 years and older—and was granted under a priority review process.

"This approval opens an important new chapter in diabetes care for young children with stage 2 type 1 diabetes and their families,” said Kimber Simmons, MD, MS, associate professor of pediatrics, Barbara Davis Center, in a statement. “This is especially important because these children are often at the highest risk of progressing quickly and without warning. Delaying the onset of stage 3 type 1 diabetes during the years when management is often most difficult because of a child’s small size and dependence on caregivers could have a truly meaningful impact for families."

Teplizumab-mzwv is now the first disease-modifying therapy for children aged 1 year and above diagnosed with stage 2 T1D. The drug works by targeting the immune system before clinical disease onset, aiming to delay the autoimmune destruction of insulin-producing beta cells in the pancreas.

The approval is supported by 1-year interim data from the PETITE-T1D (NCT05757713) phase 4 study, a single-arm, nonrandomized, open-label, multicenter trial designed to evaluate the safety and pharmacokinetics of teplizumab-mzwv in young children.

The trial enrolled 23 children under 8 years of age with stage 2 T1D, each receiving a 14-day course of intravenous teplizumab once daily.² The mean participant age in the study was 4.8 (range, 1.7-6.8) years. Median follow-up duration was approximately 52 (range, 3.9-77.1) weeks. All participants experienced at least 1 treatment-emergent adverse event (TEAE), with most being mild to moderate in severity. No grade 4 or 5 TEAEs were reported, and 3 participants discontinued treatment due to adverse events, including anemia, elevated liver enzymes, and a maculo-papular rash.

Notably, only 2 of 23 participants progressed to stage 3 T1D, yielding an estimated probability of non-progression of 89.6% (95% CI, 64.3%–97.3%) at the time of the interim analysis. These findings were consistent with teplizumab's established safety profile in older age groups, with no new safety signals identified.

Teplizumab-mzwv was first approved in the US in November 2022 for adults and children 8 years and older with stage 2 T1D.¹ It is also approved in the EU, the UK, China, Canada, Israel, Saudi Arabia, the UAE, Kuwait, and Brazil for the same population.

Sanofi is also pursuing an additional FDA review for a potential indication to delay progression of stage 3 T1D in patients 8 years and older who have been recently diagnosed with clinical-stage disease. If granted, that approval would represent a further evolution in teplizumab's role across the T1D disease continuum.

The expanded pediatric approval signals a broader shift in the treatment paradigm—from managing T1D after diagnosis to intervening during the presymptomatic window, when the opportunity to preserve beta-cell function is greatest.

"The autoimmune attack driving this disease often begins early in life, and the burden that autoimmune T1D poses in this very young population and their families is significant,” said Christopher Corsico, global head of development, Sanofi, in a statement. "This approval underscores the importance of targeting the immune system early in autoimmune type 1 diabetes, aiming to impact its natural progression by delaying the loss of insulin production in the pancreas.”

References

1. Sanofi's Tzield approved in the US to delay the onset of stage 3 type 1 diabetes in young children. Sanofi. Press release. April 22, 2026. Accessed April 22, 2026. https://www.sanofi.com/en/media-room/press-releases/2026/2026-04-22-05-05-00-3278650

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. 2026;69(2):330-342. doi:10.1007/s00125-025-06586-1