Clinicians issue guidance for first approved immunotherapy for children 8-17 newly diagnosed with type 1 diabetes

A national group of clinical trial investigators and pediatric diabetes specialists has published practical guidance for using teplizumab in children and adolescents ages 8 to 17 newly diagnosed with stage 3 type 1 diabetes. The guidance follows the U.S. Food and Drug Administration's June 2026 expansion of teplizumab's approval to this age group. Teplizumab is an immunotherapy that slows immune attack on remaining insulin-producing beta cells, while insulin remains essential for blood sugar control. The guidance appears as a perspective in Diabetes Care.

The FDA expansion was granted under accelerated approval and relied on evidence from PROTECT, a trial of 328 children and adolescents. Participants who received teplizumab preserved more C-peptide, a marker of the body's own insulin production, after 78 weeks than those who received placebo. Nearly 95 percent maintained a clinically meaningful level of insulin production, compared with about 79 percent in the placebo group. Higher C-peptide levels have been linked in separate studies to fewer severe low blood sugar episodes, lower insulin needs and lower risk of some complications, including diabetic eye disease. The source did not identify trial funding.

The guidance, led by Kimber Simmons of the Barbara Davis Center for Diabetes at the University of Colorado Anschutz, addresses candidate selection, family conversations about benefits and risks, and integration with standard diabetes care. Teplizumab was already approved to delay onset of stage 3 disease in people age 1 and older with stage 2 type 1 diabetes. It is given as two 12-day courses of daily intravenous infusions, usually six months apart. Reported side effects include rash, headache, nausea and temporary lymphocyte decline; more serious risks include cytokine release syndrome, infections and viral reactivation.

For families, the change creates a disease-modifying option alongside insulin at diagnosis, when some beta cells often remain. The PROTECT trial was interventional, so it can show that teplizumab preserved more beta-cell function than placebo over 78 weeks. But because the approval used C-peptide as a surrogate marker, it cannot yet prove durable clinical outcomes such as fewer severe hypoglycemia episodes or long-term complications; longer follow-up and real-world data are needed to confirm those benefits.