Beta Late Than Never: Delaying Diabetes with Teplizumab

For families facing type 1 diabetes, time is everything. Delaying disease progression by a few extra months, or even years, can mean fewer injections, less stress, and a chance for kids to be kids a little longer.

For the first time, there is a way to delay, not just manage, type 1 diabetes (T1D). Teplizumab, a humanized anti-CD3 monoclonal antibody, has earned headlines as the first drug to pause the autoimmune attack on insulin-producing β cells (Herold et al. 2023). It does not cure diabetes, but it buys precious time, especially for at-risk children, by shifting the immune response and slowing the progression of the disease.

In this blog, we explore the clinical significance of teplizumab for type 1 diabetes.

Why Current Treatments Were Not Enough

T1D is a chronic condition affecting over 9 million people worldwide (Bell and Lain 2025). It develops when the body stops producing enough insulin, causing blood sugar to rise to dangerous levels. The disease begins when the immune system mistakenly attacks the β cells in the pancreas that produce insulin.

Current treatment focuses on replacing insulin and monitoring glucose levels. While lifesaving, these approaches do not address the autoimmune process itself, leaving a gap in managing the early stages of the disease.

Teplizumab changes that. It is the first disease-modifying therapy for T1D, targeting the root cause by retraining the immune system to slow the T-cell attack on β cells.

How Teplizumab Works

Teplizumab is a monoclonal antibody drug that binds to CD3 receptors on T cells, reducing the harmful ones attacking β cells while boosting regulatory T cells that calm the immune response. This creates a more balanced immune system and helps protect the insulin-producing cells in the pancreas.

In prevention studies, teplizumab roughly doubled the time it took for T1D to develop. After four years, only around 45% of people who received the drug progressed to insulin-dependent T1D compared to 72% on placebo. The median time to diagnosis was approximately 50 months for teplizumab compared to 25 months for placebo, representing an average delay of two years. Extended follow-up revealed that the benefit persisted even longer, with the median time to diagnosis reaching approximately 60 months in the teplizumab group compared to 27 months in the placebo group (Herold et al. 2019; Sims et al. 2021).

Protecting Insulin Early

The PROTECT Phase III trial tested teplizumab in children and adolescents who had recently been diagnosed with T1D. Participants received two 12-day courses of the drug six months apart. After 78 weeks, 95 percent of those treated maintained a clinically meaningful level of stimulated C-peptide, a marker indicating that the pancreas was still producing insulin, compared to 79 percent in the placebo group (Ramos et al. 2023).

Preserving even a small amount of natural insulin can make life with diabetes easier, helping to keep blood sugars steadier, reducing the number of injections, and smoothing the transition into long-term care. This benefit was observed despite other measures, such as HbA1c — a test that measures average blood sugar over several months —being similar between groups (Sims et al. 2021).

Fortunately, side effects were generally mild. The most common symptoms were a rash, headache, and transient lymphopenia, a temporary decrease in white blood cells that typically returns to normal on its own. A small number of participants developed cytokine-release syndrome. This short-lived immune reaction can cause fever or fatigue, but it is rare, occurring in approximately 1 to 2% of cases, and typically resolves quickly with monitoring.

From Trials to Treatment

Due to the strong results observed in the clinical trials, the U.S. Food and Drug Administration (FDA) granted teplizumab Breakthrough Therapy and Priority Review designations, both intended to accelerate evaluation of promising drugs. Teplizumab received full FDA approval in November 2022 to delay the onset of stage 3 T1D (FDA, 2022).

It has not yet been authorized for routine use in the UK or EU, though some children are receiving it through early access programs. One of the first was Sam, a 14-year-old with stage 2 markers, treated at Birmingham Women’s and Children’s Hospital. His mother said, “We are so happy that Sam does not have to worry about his blood sugar yet… He can just be a normal teenager.”

Dr. Renuka Dias, part of the care team, reinforced the significant effect of teplizumab approval on patient lives, stating, “Being able to delay insulin-dependent diabetes will have a huge impact on a child’s life. It means we are letting children have a normal childhood for much longer”.

Looking Ahead

Teplizumab’s approval marks a shift in T1D care, moving from symptom management to slowing the course of the disease. Ongoing studies are testing repeat dosing, combination therapies, and their use in both new-onset and long-standing T1D (Herold et al. 2023). Screening programs, such as the ELSA study in the UK, are working to identify children at risk early so they can benefit from preventive treatment.

Taken together, the recent approval of teplizumab for T1D and the ongoing research studies to optimize treatment and improve risk identification highlight a promising future for T1D care and provide hope for patients afflicted with this condition.