The role of clinical trials in drug regulation

Clinical trials and the judgement of the appropriateness of the clinical outcomes are of paramount importance in the process of the evaluation procedure before marketing authorization. Even if the mode of action of the drug remains to be elucidated, the outcome of properly designed and well-performed clinical trials will override this drawback if the results are in favor of the new drug. The critical issue from the medical point of view is the appropriateness of the outcome as "predictor" in terms of therapeutic efficacy. The relationship between pharmacologic effects and the therapeutic efficacy is often a matter of concern, particularly in short-term trials with drugs intended for long-term use and prophylactic indications. In conclusion, despite controversies on their value, clinical trials remain the cornerstone in drug evaluation as a scientific basis for drug regulation.