Cevostamab is a bispecific antibody designed to target FcRL5 (also known as IRTA2) on malignant B cells and CD3 on T cells. Its primary application is in the treatment of relapsed or refractory B-cell malignancies, particularly multiple myeloma and certain types of non-Hodgkin lymphoma. By simultaneously binding to FcRL5 on tumor cells and CD3 on T cells, cevostamab facilitates the recruitment and activation of T cells to the cancer cells, leading to targeted cell lysis. This antibody has shown promise in early-phase clinical trials, where it demonstrated anti-tumor activity in patients who have exhausted standard treatment options. Its mechanism enables T-cell engagement independent of MHC recognition, which is especially valuable in cancers that downregulate MHC expression to evade immune detection. Due to its potent T-cell activating properties, cevostamab is typically administered in controlled clinical settings with monitoring for cytokine release syndrome (CRS), a common side effect. It represents a novel immunotherapeutic approach for hematologic cancers, particularly where target antigen expression is high and treatment options are limited.