[The development history and future perspective of molecularly targeted therapy]

The origin of molecularly targeted drugs dates back to 'magic bullet' theory proposed by Paul Ehrlich. The success of Abl tyrosine kinase inhibitor, imatinib for the treatment of chronic myeloid leukemia realized that small molecules inhibiting ATP binding can become specific inhibitors for the relevant kinases. Subsequently, a number of kinase inhibitors which targets various signal transduction molecules, are in the clinical field or under development. The clinical success of antibody therapeutics has been achieved by the genetic engineering which makes human-mouse chimeric, humanized or human antibody. To augment the therapeutic effects of antibody, radioisotope-conjugate antibody and antibody-drug conjugate have come to the clinical field. In the near future, we have to develop the combination therapy of molecularly targeted drugs and also inhibitors for epigenetic and transcriptional regulators.