Identification and successful Teplizumab infusion in a stage 2 type 1 diabetes adult patient: Twelve-Month follow-up without progression

Aims: Teplizumab is the only disease-modifying immunotherapy approved by the FDA and EMA for the delay of Type 1 diabetes mellitus (T1D) progression from the presymptomatic stage 2 to the symptomatic stage 3 of the disease. Teplizumab is available in Italy through the compassionate individual patient request program since october 2024. Here we report real world data and experience of treating a 19-year-old male with stage 2 T1D. Methods: A 19-years-old male with and preexisting autoimmune thyroiditis was diagnosed with stage 2 T1D in an ambulatorial setting through routine check-up for glycemia followed by autoantibodymeasurement. The patient was treated for fourteen consecutive days with teplizumab in a Day Hospital (DH) setting, according to the treatment protocol and has been followed hereafter for twelve months. Results: Treatment was well-tolerated, six and twelve months after treatment glycemic status and beta-cell function have remained stable. The lymphocytes dynamicswas consistent with teplizumab's mechanism of action. Conclusions: Our real-world experience provides important clues on the feasibility and protocol adaptation in a DH setting.