involves greater numbers of patients than in phase II, aimed at gaining additional data about effectiveness and safety needed to evaluate the benefits and risks of the drug. Results yield data that will provide information that eventually will go on physician labeling.
A larger number of patients (several thousand) take part in this phase. It is generally conducted simultaneously at multiple test centers in a variety of countries. Additional parameters such as rare undesirable side effects, allergies, sensitization, etc. are carefully noted, since when phase III of the clinical trial is concluded, the application for approval is made.
The third and last round of testing before application for market of a drug is conducted on large populations of affected patients. These studies usually compare the new drug with standard therapy for the relevant disease. Phase III trials usually provide the information included in the drug's package insert and labeling.