Unspecified AML-associated surface antigen

Unspecified AML-associated surface antigen is a generic placeholder term used to refer to various proteins expressed on the plasma membrane of acute myeloid leukemia (AML) cells that serve as therapeutic targets. These antigens, such as CD33, CD123, and CLEC12A (CLL-1), are typically overexpressed on leukemic blasts and leukemic stem cells compared to normal hematopoietic cells, making them ideal candidates for targeted therapies including monoclonal antibodies, antibody-drug conjugates, and CAR-T cells. The primary biological role of these antigens varies by specific molecule; for instance, CD33 is involved in cell signaling and adhesion, while CD123 (IL-3R alpha) mediates cytokine signaling essential for cell survival and proliferation. In clinical trial databases and drug development pipelines, this term is frequently employed when the specific molecular target of a novel therapy has not been publicly disclosed or when a therapy is designed to target multiple myeloid markers. A major clinical challenge in targeting these antigens is 'on-target, off-tumor' toxicity, particularly the depletion of normal hematopoietic stem and progenitor cells, which can lead to severe and prolonged cytopenias.

Other names

AML-associated surface antigenAML surface markerMyeloid-associated antigenAcute myeloid leukemia-associated antigen

Drugs targeting these antigens typically utilize monoclonal antibodies, antibody-drug conjugates (ADCs), bispecific T-cell engagers (BiTEs), or chimeric antigen receptor (CAR) T-cells to induce direct cell lysis, antibody-dependent cellular cytotoxicity (ADCC), or deliver cytotoxic payloads to AML blasts.