BackgroundThe management of Type 1 Diabetes Mellitus (T1DM) is a significant clinical challenge. This study evaluated the efficacy of teplizumab, an immunomodulatory drug, in patients with T1DM, using a systematic review and meta‐analysis approach.MethodsWe systematically searched multiple databases including Medline, Scopus, and others up to 10 January 2024, without language or regional restrictions. We included randomized controlled trials (RCTs) comparing teplizumab with placebo in T1DM patients.ResultsOur analysis incorporated 8 RCTs, predominantly involving participants aged 7–35 years, diagnosed with T1DM and treated with 14‐day courses of teplizumab. The primary outcomes included insulin use, C‐peptide levels, and HbA1c levels. We observed a significant reduction in insulin use in the teplizumab group standardised mean difference of −0.50 (95% Confidence Interval [CI]: −0.76 to −0.23, p < 0.001; I2 = 49%). C‐peptide levels were consistently higher in the teplizumab group, indicating improved endogenous insulin production. However, no significant change was noted in HbA1c levels between the groups. Quality assessment indicated a low risk of bias in most studies.ConclusionsTeplizumab has a significant impact on reducing insulin dependence and enhancing endogenous insulin production in T1DM patients. However, its effect on long‐term glycaemic control, as indicated by HbA1c levels, remains inconclusive.