FDA Grants Accelerated Approval to Tzield for Children with Stage 3 T1D

The U.S. Food and Drug Administration (FDA) has granted accelerated approval to Tzield (teplizumab-mzwv) to delay the decline of endogenous insulin production in children aged 8 to 17 years who were recently diagnosed with stage 3 type 1 diabetes (T1D). The decision expands the use of the first disease-modifying therapy for autoimmune T1D beyond its earlier indication for delaying disease onset in high-risk individuals.

The approval is based on findings from the Phase 3 PROTECT trial (NCT03875729) and additional evidence from a global clinical development program involving more than 900 patients treated with Tzield.

Targeting the Autoimmune Drivers of Type 1 Diabetes

Tzield is a CD3-directed monoclonal antibody that modifies the immune response responsible for the destruction of insulin-producing pancreatic beta cells. Unlike insulin replacement therapies that manage blood glucose after substantial beta-cell loss, Tzield targets the underlying autoimmune process that drives disease progression.

Type 1 diabetes develops through a series of stages. By stage 3, patients experience clinical hyperglycemia and often require lifelong insulin therapy. Preserving residual beta-cell function at diagnosis has long been considered an important goal because it may improve metabolic control and reduce disease burden.

Aaron J. Kowalski, Chief Executive Officer of Breakthrough T1D, noted that approximately 64,000 people are diagnosed with T1D each year and emphasized the importance of introducing therapies that address the disease’s autoimmune progression rather than focusing solely on glucose management.

PROTECT Phase 3 Trial Demonstrated Preservation of Beta-Cell Function

The randomized, double-blind, placebo controlled PROTECT study enrolled 328 children and adolescents aged 8 to 17 years who had been diagnosed with stage 3 T1D within the previous six weeks. Participants received two 12-day courses of Tzield or placebo, administered six months apart, alongside standard diabetes care.

The study met its primary endpoint, demonstrating a significant slowing in the decline of beta-cell function compared with placebo. Mean C-peptide levels, measured by area under the curve during a four-hour mixed-meal tolerance test, were better preserved in patients receiving Tzield. The treatment difference in least-squares means was 0.13 pmol/mL (95% CI: 0.09–0.17; p<0.001).

Safety findings were consistent with previous studies. The most common adverse reactions included lymphopenia, vomiting, rash, leukopenia, diarrhea, neutropenia, elevated liver transaminases, and headache. Serious risks associated with treatment include cytokine release syndrome and potentially life-threatening viral reactivation, particularly in immunocompromised patients.

Confirmatory Trial Underway

Because the approval was granted through the FDA’s accelerated approval pathway, continued authorization will depend on confirmation of clinical benefit in post-marketing studies. The ongoing Phase 3 BETA-PRESERVE trial (NCT07088068) is currently enrolling participants and will evaluate whether preservation of C-peptide translates into meaningful long-term clinical outcomes.

Christopher Corsico, Global Head of Development at Sanofi, said the approval introduces a new treatment approach for recently diagnosed stage 3 T1D by allowing clinicians to intervene against the autoimmune attack on beta cells earlier in the disease course.

The approval follows the FDA’s April 2026 decision to expand Tzield’s stage 2 T1D indication to children as young as one year of age. The therapy is also approved in multiple international markets, including the European Union, United Kingdom, China, Canada, Australia, Brazil, Switzerland, and several Middle Eastern countries, with additional regulatory reviews ongoing.

 Reference

Sanofi’s Tzield approved in the US as the first disease modifying therapy for patients recently diagnosed with stage 3 type 1 diabetes