Type 1 diabetes (T1D) is an organ-specific autoimmune disease caused by the progressive immune-mediated destruction of the insulin-secreting pancreatic beta cells, resulting in the lifelong need for exogenous insulin therapy. According to recent estimates, T1D currently affects about 8.4 million individuals worldwide. As a definitive biological cure for T1D remains elusive, there is a significant need for innovative therapeutic strategies that can safely and effectively modify the disease’s progression through its various stages. Ideal therapeutic goals in T1D include the prevention of immune-mediated beta-cell destruction, the preservation of residual beta-cell mass and insulin secretory capacity, and the replacement and/or regeneration of beta cells. In this regard, an important research area focused on the identification of a definitive biological cure for T1D is represented by the investigation of immunotherapies used as disease-modifying agents. This chapter reviews recent progress in therapies that address various T1D-related immunometabolic dysfunctions in order to maintain beta-cell function in individuals at different stages of T1D. One notable advancement is teplizumab, which was approved in November 2022 by the US Food and Drug Administration (FDA) as the first T1D disease-modifying agent capable of delaying the onset of stage 3 T1D in adults and children with stage 2 T1D aged 8 years and older.