Anticancer Drug Development Unique Aspects of Pharmaceutical Development

Around the world, tremendous resources are being invested in prevention, diagnosis, and treatment of cancer. Cancer is the second leading cause of death in Europe and North America. Discovery and development of anticancer agents are the key focus of several pharmaceutical companies as well as nonprofit government and non-government organizations, like the National Cancer Institute (NCI) in the United States, the European Organization for Research andTreatment of Cancer (EORTC), and the British CancerResearch Campaign (CRC). Identification of cytotoxic compounds led the development of anticancer therapeutics for several decades. Advances in cancer treatment, however, continued to be limited by the identification of unique biochemical aspects of malignancies that could be exploited to selectively target tumor cells. Schwartsmann et al. noted in 1988 that of over 600,000 compounds screened by then, less than 40 agents were routinely used in the clinic [1]. The recent growth in molecular sciences and the advances in genomics and proteomics have generated several potential new drug targets, leading to changes in the paradigms of anticancer drug discovery toward molecularly targeted therapeutics. These shifting paradigms have not only resulted in the greater involvement of biological scientists in the drug discovery process but also required changes in the screening and clinical evaluation of drug candidates. Both small and large molecular compounds continue to be investigated as anticancer agents. The discovery and development of anticancer drugs, especially cytotoxic agents, differ significantly from the drug development process for any other indication. The unique challenges and opportunities in working with these agents are reflected in each stage of the drug development process. This chapter will highlight the unique aspects of anticancer drug discovery and development.