FDA approves Tzield as first disease-modifying T1D therapy

FDA has granted accelerated approval to Tzield (teplizumab-mzwv) to delay the decline in endogenous insulin production in children aged 8 to 17 years who were recently diagnosed with stage 3 type 1 diabetes. The approval expands the role of teplizumab beyond disease prevention and into treatment after clinical diagnosis.

Until now, Tzield has been used to delay progression from stage 2 to stage 3 type 1 diabetes in at-risk individuals. The new indication applies to patients who've already developed symptomatic disease but still retain some functioning insulin-producing beta cells. Preserving beta-cell function may help maintain endogenous insulin production and potentially alter the course of disease progression.

The approval was supported by the phase 3 PROTECT trial, which enrolled children and adolescents within six weeks of a stage 3 type 1 diabetes diagnosis. Patients treated with teplizumab experienced a significantly slower decline in C-peptide levels, a marker of endogenous insulin production, compared with placebo.

The decision may influence how clinicians approach newly diagnosed type 1 diabetes. In addition to initiating insulin therapy, pediatric endocrinologists now have an FDA-approved option that targets the underlying autoimmune process responsible for beta-cell destruction.

Tzield carries a boxed warning for serious viral reactivation, including Epstein-Barr virus and cytomegalovirus. Patients should be screened for active infection before treatment. Other important risks include cytokine release syndrome, hypersensitivity reactions, lymphopenia, neutropenia, leukopenia, and elevated liver enzymes. The most common adverse reactions include vomiting, rash, headache, and increased liver transaminases.

“The approval of Tzield for individuals ages 8-17 with stage 3 type 1 diabetes is an exciting milestone that reinforces the importance of beta cell preservation and provides an opportunity to change the course of the disease for those living with T1D,” said Aaron J. Kowalski, PhD, CEO of Breakthrough T1D. “For the first time, individuals diagnosed with type 1 diabetes in stage 3 will have the option to treat the disease rather than just the symptoms.”

Sources:

FDA. 2026 June 12. [Press release]. FDA Approves Drug for Pediatric Stage 3 Type I Diabetes

Sanofi. 2026 June 12. [Press release]. Sanofi’s Tzield approved in the US as the first disease-modifying therapy for patients recently diagnosed with stage 3 type 1 diabetes