Paris, June 13, 2026. The US Food and Drug Administration (FDA) has granted accelerated approval to Tzield (teplizumab-mzwv) to delay the decline in endogenous (own) insulin production in children aged eight to 17 years recently diagnosed with stage 3 T1D. Tzield is not effective as a disease-modifying therapy in non-autoimmune dysglycemic conditions.
About PROTECT
PROTECT was a phase 3, randomized, double blind, placebo-controlled, multinational study. It enrolled 328 children and adolescents (Tzield n=217, placebo n=111) aged eight to 17 years diagnosed with clinical stage 3 T1D in the preceding six weeks; randomization ratio of Tzield to placebo was 2:1. Participants received a first course of 12 daily infusions (of either Tzield or placebo) at randomization, followed by a second course of 12 daily infusions after 26 weeks (approximately six months). All participants received standard-of-care medicines as required.
About autoimmune T1D
T1D is a progressive autoimmune disease where the body’s ability to regulate blood sugar levels is impacted due to the gradual destruction of insulin producing beta cells by one’s own immune system. There are four stages to the progression of T1D:
In stage 1, the autoimmune attack to the beta cells has started, and this can be detected by the presence of 2 or more T1D-related autoantibodies in the blood. During stage 1, blood sugar levels are in a normal range (normoglycemia). At this stage, T1D is presymptomatic.
In stage 2 (also presymptomatic), in addition to the presence of 2 or more T1D-related autoantibodies, blood sugar levels are now abnormal (dysglycemia) due to the progressive loss of beta cells / beta-cell function.
Stage 3 (also known as clinical stage) comes once a significant portion of the beta cells have been destroyed. At this point, rising blood sugar levels reach the point of clinical hyperglycemia (which defines diabetes), and many people will start to experience the classic symptoms that come with the onset of stage 3 T1D: increased thirst, frequent urination, unexplained weight loss, blurred vision, and generalized fatigue. Management of stage 3 T1D requires daily and burdensome insulin replacement therapy.
Stage 4 is defined as long-standing autoimmune T1D, often accompanied by evidence of chronic diabetic complications, where little to no beta-cell function remains (it’s been estimated that beta-cell mass is reduced by up to 95%). At this point, the T1D-related autoantibodies might not be present anymore in the blood, as most beta cells have been rendered useless by the autoimmune attack.
About Tzield
Tzield (teplizumab) is a CD3-directed monoclonal antibody. Tzield is the first disease- modifying therapy in autoimmune T1D; it was approved in the US in November 2022 to delay the onset of stage 3 T1D in adults and children eight years and older diagnosed with stage 2 T1D. In April 2026, the FDA expanded this indication to include children aged one year and above. Today, it is also approved to delay the onset of stage 3 T1D in adults and children eight years and older with stage 2 in the UK, the EU (under the name Teizeild), China, Australia, Canada, Israel, Saudi Arabia, the UAE, Kuwait, Brazil and Switzerland. Other regulatory reviews are ongoing.
IMPORTANT SAFETY INFORMATION
Tzield may cause serious side effects
Viral Reactivation
Epstein-Barr virus (EBV) and cytomegalovirus (CMV) are common viruses that may stay inactive in your body after an initial infection. Tzield may cause these viruses to become active again which, especially in people with a weakened immune system, can become serious and potentially life-threatening. These infections can happen during treatment with Tzield and for up to 2 months after your last dose. Your healthcare provider will test you for active EBV and CMV infections before treatment with Tzield. Contact your healthcare provider right away if you develop symptoms of an infection during or after treatment with Tzield (such as fever, swollen glands, or fatigue).
Cytokine release syndrome (CRS)
Signs and symptoms may start during the first 5 days of Tzield treatment and could include fever, nausea (with or without vomiting), feeling tired (fatigue), headache, muscle and joint pain, or increased liver enzymes in your blood. Tell your healthcare provider right away if you develop any signs and symptoms of CRS during treatment with Tzield.
Serious Infections
Treatment with Tzield may lower your immune system’s ability to fight infections, which may increase your risk of getting a serious infection. Tzield is not recommended if you currently have a serious infection, or an infection that keeps coming back or does not go away (chronic infection), other than a minor skin infection. Contact your healthcare provider right away if you develop symptoms of an infection during or after treatment with Tzield such as: fever or chills; redness, warmth, or swelling of the skin; feeling tired; cough or shortness of breath; severe stomach pain or diarrhea.
Decrease in white blood cells
Tzield may cause a decrease in a type of white blood cell called lymphocytes. A decrease in white blood cells is a serious, but common side effect that can affect your body’s ability to fight infections. A decrease in white blood cell counts can happen after your first dose of any treatment course. Your white blood cell counts will start to go back to normal after your fifth dose of Tzield. Some people may develop longer and more severe decreases in lymphocytes.
