Antigentargeted

Antigen-targeted refers to therapeutic approaches that recognize and bind to specific antigens—molecules or protein structures—expressed on the surface or within target cells or pathogens. The goal is to direct a treatment to diseased tissues while limiting effects on normal tissues. The term is widely used in immunology and oncology, and it also applies to infectious disease interventions and diagnostic tools.

In cancer, antigen-targeted strategies rely on selecting tumor-associated or tumor-specific antigens to guide therapies. Common modalities include monoclonal antibodies that bind surface antigens, antibody-drug conjugates that deliver cytotoxic agents to the target cells, and bispecific antibodies that recruit immune effector cells to destroy them. Cellular therapies, such as chimeric antigen receptor (CAR) T cells and CAR-NK cells, are engineered to recognize particular antigens on malignant cells. Vaccines and dendritic cell therapies may prime the immune system against presented tumor antigens.

Key criteria for antigen selection include high and consistent expression on target cells, minimal or absent expression on healthy tissues, accessibility on the cell surface, and a role in tumor survival to reduce the likelihood of antigen loss. Effective antigen targeting depends on factors such as antigen density, tumor heterogeneity, and the tumor microenvironment. Safety considerations include on-target off-tumor toxicity and the potential for immune escape when target antigens are downregulated or lost.

Representative examples include rituximab targeting CD20 in B-cell malignancies, trastuzumab targeting HER2 in breast cancer, brentuximab vedotin targeting CD30, and anti-CD19 CAR-T therapies. Ongoing research seeks novel antigens and improved delivery methods to expand the applicability and safety of antigen-targeted interventions.