One of the paramount goals of clinical drug development is to answer two fundamental questions: How much ? and How often ? should a novel drug or dosage form be administered in order to achieve the desired therapeutic effect with no or acceptable drug-related toxicity.

In the past, dose/response assessments have frequently been used to guide the selection of clinically tested dosing regimens by determining the effect intensity and duration in response to the administration of escalating single or multiple dose regimens. This approach, however, is hampered by severe limitations with regard to predictability of drug response, especially if dosage regimen, dosage form and/or mode of administration are changed.

In contrast, exposure/response assessments in form of PK/PD modeling have more recently become available as a more sophisticated analysis tool. Although analytically more challenging, PK/PD-based response assessments generally provide a substantially improved predictive power compared to dose/response assessments. In addition, they allow for consideration of the temporal aspects in effect intensity and provide a more rationale scientific framework for the relationship between dose and response.

The presentation will discuss these concepts in detail and will provide examples for the superiority of exposure/response compared to dose/response assessments.