A clinical trial is a research study in which volunteers receive investigational drugs under the supervision of a physician and other research professionals. Clinical trials can only take place once satisfactory information has been gathered on the quality of the investigational drug and its non-clinical safety in animals.  

Clinical trials require prior review and approval by the Food and Drug Administration (FDA) of an Investigational New Drug Application (IND).  In addition, clinical trials require approval by an Investigational Review Board (IRB) that is responsible for ethical review of human research and protecting the rights of human study subjects.  The IRB must approve the clinical protocol prior to initiation of clinical trials and will have ongoing responsibility for overseeing the conduct of the clinical trial.

 

After a study phase is completed, the data is collected to determine the drug's effectiveness, if it is safe and if there are any side effects. Depending on the results, researchers then determine whether to stop testing or move to the next phase of study. After phase III of a study is complete, researchers decide if the results are medically important and may decide to submit them to journals for peer-review. Data then may be submitted to the Food and Drug Administration (FDA) for approval of the drug for marketing.

If a drug is approved, the sponsor may continue to conduct studies that compare the new drug—in terms of its safety, effectiveness, and cost—to other drugs already on the market or assess a drug's long-term effectiveness and its impact on the quality of a person's life.