The intravenous drug, teplizumab-mzwv (Tzield), is for adults and children 8 years and older who are at high risk for type 1 diabetes but haven’t yet been diagnosed with the condition and have not yet become reliant on insulin shots. Tzield is in a new family of medicines that slow the immune system’s attack on insulin-producing cells in the pancreas, which is the underlying cause of type 1 diabetes. “Today’s approval of a first-in-class therapy adds an important new treatment option for certain at-risk patients,” said John Sharretts, MD, the director of the Division of Diabetes, Lipid Disorders, and Obesity in the FDA’s Center for Drug Evaluation and Research, in a statement. “The drug’s potential to delay clinical diagnosis of type 1 diabetes may provide patients with months to years without the burdens of disease.” In type 1 diabetes, the pancreas stops making enough insulin, a hormone responsible for helping the body convert sugars in the foods we eat into energy. Without insulin, sugars accumulate in the bloodstream, a condition that without treatment can lead to serious complications like heart disease, kidney failure, amputations, and blindness. People with type 1 diabetes need lifelong treatment with insulin shots or an insulin pump. According to the American Diabetes Association, most people who develop type 1 diabetes inherit risk factors from both parents. People with a parent or sibling with type 1 diabetes can have blood tests to see if their body is starting to attack insulin-producing cells in the pancreas. Once these attacks are underway, people almost always go on to develop type 1 diabetes and require insulin shots, but the pace of this progression varies. Tzield can slow the progression in people who have what’s known as stage 2 disease. According to Emory University, this isn’t yet full-blown type 1 diabetes requiring treatment with insulin, but people with stage 2 disease do have damaged insulin-producing cells in the pancreas and abnormal blood sugar levels. The FDA approved Tzield on the basis of a clinical trial with 76 patients who had stage 2 disease. In this trial, scientists randomly assigned participants to receive daily infusions of Tzield or a placebo for 14 days. After a median follow-up period of 51 months, 45 percent of the patients in the Tzield group developed type 1 diabetes, compared with 72 percent with the placebo. The average progression time to type 1 diabetes was also twice as long with Tzield — 50 months compared with 25 months in the placebo group. Particularly for children at high risk for type 1 diabetes, stalling this diagnosis by several years can be crucial for giving them time to become more mature and capable of navigating daily life with this condition. “A delay in the onset of type 1 diabetes will have a tremendous impact on the daily lives of people at risk for diabetes, their families, and the overall health system,” said Aaron Kowalski, PhD, the chief executive officer of the Juvenile Diabetes Research Foundation, in a statement after the FDA approved Tzield. “It would free them from the constant burden and stress of blood-sugar monitoring and insulin administration,” Dr. Kowalski said. “It would free them from the worry and fear of short- and long-term complications, while giving them the opportunity to learn more about disease management.” The most common side effects of Tzield include decreased white blood cell levels, rashes, and headaches, the FDA said. Rarer, more serious, side effects include infections, interference with routine childhood vaccinations, and what’s known as cytokine release syndrome — when the immune system can go into overdrive and cause fever, body aches, and organ failure. Approval was delayed by the FDA in July 2021 when regulators asked for more information about how the body responds to the drug. It was postponed again in June 2022 as the FDA extended its review period for the medicine, as its developer Provention Bio said at the time.