Clinical trials are research studies performed on people to assess a medical, surgical, or behavioral intervention. Clinical trials are the primary way researchers decide whether new drugs or diets are safe and effective for people. Often, clinical trials are used to learn if a new treatment is more effective than the standard treatment. Below are descriptions of some different kinds of clinical research.
Clinical trials advance through four phases to test treatments, identify suitable dosages, and discover side effects.
A Phase I Trial tests an experimental treatment on a small group of subjects (20 to 80) to judge its safety, side effects and to determine a suitable dosage.
A Phase II Trial aims to obtain preliminary data on whether a drug works in people who have a specific condition. While Phase I focuses on safety, Phase II focuses on effectiveness. These trials also continue to study safety, especially short-term side effects. Phase II can last several years.
A Phase III Trial studies different populations and different dosages to gather more information about safety and effectiveness. A Phase III trial usually consists of several hundred to about 3,000 individuals. If the FDA agrees that results are positive, they will approve the experimental drug or device.
A Phase IV trial occurs after the FDA approves an experimental drug or device. The drug or device is closely monitored in large, diverse populations for its effectiveness and safety.
Some people participate in clinical trials due to treatments not working or not entirely having treatments for their health problems. Many people partake in clinical trials to play an active role in assisting researchers in learning more about specific health problems.