[Design and analysis of clinical trials].

The purpose of a therapeutic clinical trial is to determine the value of a treatment. The main objectives of phase I trials have been to determine a dose that is appropriate for use in phase II and III trials and to determine information about the pharmacokinetics of distribution of the drug. Phase II trials have been performed to determine whether a particular regimen or drug is worthy of phase III evaluation. Phase III trials attempt to prove the usefulness of treatment and determine the new treatment strategy.