Clinical trials and biomarker development with molecularly targeted agents and radiotherapy.

Introduction: The conventional paradigm of drug development used for cytotoxic chemotherapeutic agents may not represent the most effective method of assessing the safety and biological activity of molecularly targeted agents, given that the latter may offer improved therapeutic indices with less toxic effects on normal tissues.

Objectives: With the number of novel therapeutics in oncology entering the investigative arena, there is a need to expedite the drug development process by allowing for optimal selection of agents with the greatest likelihood of having clinical benefit over those of lower potential utility.

Discussion: The high throughput techniques now available in genomic, proteomic and metabolomic profiling should allow for more effective preclinical investigation with the identification of biomarkers or indicators of treatment response, leading to increased clinical efficacy with appropriate patient selection.

Conclusion: With this in mind, current investigation should be directed at validating novel endpoints in order to accelerate the drug development and approval process with targeted therapeutics in oncology.