Background: Type one diabetes mellitus (T1DM) is an autoimmune disease characterized by gradual destruction of beta cells in islets of Langerhans. Teplizumab is a humanized an-ti-CD3 monoclonal antibody, which may have beneficial effects for T1DM patients. Objective: The aim of the study was to assess the safety and efficacy of teplizumab in T1DM patients. Methods: We searched electronic databases using related keywords for randomized clinical trials assessing the safety and efficacy of teplizumab. We evaluated the retrieved citations for eligibility, and we extracted the data and then analyzed it using Review Manager Software. Results: We included eight randomized clinical trials with 866 patients. Teplizumab was associated with lower insulin use than placebo at 6 months (MD =-0.17, 95% CI [-0.24,-0.09], P < 0.001), 12 months (MD =-0.12, 95% CI [-0.18,-0.06], P < 0.001), 18 months (MD =-0.22, 95% CI [-0.32,-0.11], P < 0.001) and 24 months (MD =-0.17, 95% CI [-0.28,-0.06], P = 0.003). The area under the curve of C-peptide was significantly increased in teplizumab group at 12 months (MD = 0.08, 95% CI [0.01, 0.15], P = 0.03), 18 months (MD = 0.13, 95% CI [0.01, 0.25], P = 0.03) and 24 months (MD = 0.13, 95% CI [0.01, 0.24], P = 0.03). No significant effect of teplizumab on HbA1c levels was observed at any time point. Teplizumab was found to be associated with some side effects such as lymphopenia, skin and subcutaneous tissue disorders. Conclusion: Teplizumab is associated with lower insulin use and higher AUC of C-peptide in type 1 diabetic patients with no significant effect on Hb1c levels. Besides, teplizumab has shown some adverse effects.
