The power of enzyme kinetics in the drug development process.

Drug development is a long and expensive process. It starts from the identification of a small molecule (hit compound) endowed with the ability to suppress a cellular or viral enzyme essential for the development of a given disease and proceeds through subsequent rounds of structural changes and optimization until the desired pharmacological properties are reached (lead compound). At any point of the hit-to-lead optimization process, it is of essence to monitor the behavior of the intermediate molecules with respect to their molecular targets. This involves precise mechanism of action studies as well as quantitative measurement of the performance of the compound against its target. Enzyme kinetic studies are thus an essential component of the drug development process. Relevant examples of the power of enzyme kinetics in the antiviral drug development process will be discussed in the context of anti-HIV chemotherapy.