Alsevalimab (formerly FPA-150) is a humanized, glycoengineered monoclonal antibody of the IgG1 isotype. It functions as an immune checkpoint inhibitor by targeting and blocking B7-H4 (VTCN1). The antibody is afucosylated in its Fc region, a modification designed to enhance its binding affinity to CD16 receptors on Natural Killer (NK) cells. This modification significantly boosts its ability to induce Antibody-Dependent Cellular Cytotoxicity (ADCC) against tumor cells expressing B7-H4. By combining checkpoint blockade (abrogating the negative T-cell regulation) with direct tumor cell killing (via ADCC), Alsevalimab aims to enhance the overall anti-tumor immune response. It has been investigated in clinical trials for various solid tumors, particularly gynecological and gastrointestinal malignancies.