Type 1 diabetes and delaying its onset
Type 1 diabetes is an autoimmune disease that progresses in three stages, with daily insulin needed from stage 3, and treatment at stage 2 can delay the onset of stage 3.
The disease and its stages
Type 1 diabetes is a chronic autoimmune disease in which the body's immune system destroys the beta cells in the pancreas that produce insulin, a hormone that regulates blood glucose by allowing it to move into cells to produce energy. Glucose therefore builds up in the blood and causes symptoms such as thirst, hunger, frequent urination, weight loss and tiredness. Over time the disease can affect major organs, including the heart, blood vessels, nerves, eyes and kidneys. Patients need daily insulin injections to control their glucose levels.
Type 1 diabetes often begins in childhood but can occur at any age. In 2025 an estimated 2.2 million people in the EU lived with it.
The disease progresses in three stages, and symptoms normally appear at stage 3, when daily insulin injections become necessary to manage blood glucose. These injections are a significant burden to patients, especially children and their caregivers. Delaying the onset of stage 3, particularly in children, is beneficial in diabetic care.
Delaying stage 3 with teplizumab
In November 2025 the European Medicines Agency recommended granting Sanofi Winthrop Industrie a marketing authorisation in the EU for Teizeild (teplizumab) to delay the onset of stage 3 type 1 diabetes in adults and in children from 8 years of age with stage 2 disease. At that time no treatment was authorised in the EU to delay or cure the disease. Teplizumab is an antibody that delays disease progression by slowing the rate at which the patient's body destroys its own pancreatic beta cells. It is given by intravenous infusion once daily for 14 consecutive days.
The recommendation rested on a randomised, double-blind, placebo-controlled trial in 76 patients with stage 2 type 1 diabetes. The median time to stage 3 was 50 months with teplizumab and 25 months with placebo. Over a median follow-up of 51 months, 20 (45%) of the 44 patients treated with teplizumab developed type 1 diabetes, against 23 (72%) of the 32 who received placebo. Several other studies showed that teplizumab significantly preserved the function of pancreatic beta cells compared with placebo.
The most common side effects of Teizeild were low levels of various types of white blood cells (lymphocytes, leucocytes and neutrophils), rash and low levels of blood bicarbonate, which can cause metabolic acidosis, an excess of acid in the body. The most frequent serious adverse reaction, reported in 2% of patients, was cytokine release syndrome, a serious condition causing fever, vomiting, shortness of breath, headache and low blood pressure.