ABSTRACT
With increasing knowledge of the molecular pathways responsible for carcinogenesis,1
the possibility has arisen for effective antineoplastic drugs directed against specific targets within the cancer. Such agents have the potential for improved efficacy with fewer adverse effects than with conventional chemotherapy. Central to the development of so-called ‘targeted therapy’ is identification that the target is involved in the pathogenesis of the cancer, and that inhibition of the target either inhibits the growth of a malignant cell, or enhances the effectiveness of conventional anticancer agents. Both monoclonal antibodies and small molecules have been developed against key components of signal transduction pathways, and several are in advanced stages of clinical development. The best example is the development of the monoclonal antibody trastuzumab (Herceptin) targeted against HER2, and this chapter highlights the key stages in its development. The clinical improvements that trastuzumab has brought gives much encouragement for the development of several other novel therapies, including signal transduction inhibitors (STIs) and vascular targeted agents.
