Recently, this laboratory has developed a new class of therapeutic agents termed Chemically Programmed Antibodies. The success of the antibody molecule as therapeutic agent is based on at least three properties; (i) an Fab moiety that permits antigen binding with high specificity and affinity, (ii) an Fc moiety that mediates effector functions, and (iii) a molecular weight of at least 150 kD that permits a circulatory half-life of up to 21 days.  Although conventional therapeutic agents based on small organic molecules are undoubtedly successful, they are clearly limited with respect to their short half-life in circulation, effector functions, and ability to block protein-protein interactions.  With the Chemically Programmed Antibody approach, the efficacy of small molecules can be enhanced in each of these aspects. In vitro and in vivo studies concerning enhanced biological activity bestowed upon small molecules by this approach will be presented.