Targeting of drugs to cell surface receptors

The new approach to the treatment of cancer or to immunomodulation is drug targeting. The effort to achieve either an absolute or a relative amplification of the tumoricidal effect of anticancer drugs through increased generation or acquisition of reactive molecules at the tumor site or a reduction of the toxic molecules available to the periphery has led to a number of strategies. Among them are (1) targeting using antibodies to their fragments, hormones, carbohydrates, and growth factors; (2) retargeting using bispecific antibodies; (3) construction of chimeric genes; (4) streptavidin-biotin based immunotherapy; (5) prodrug activation strategies (ADEPT); (6) antibody-targeted superantigens; and (7) gene delivery for the purpose of gene therapy.