The FDA remains committed to ensuring that FDA-approved drugs are safe and effective for Americans. As part of this commitment, we require evidence from premarket clinical trials that the medicine will be both effective and safe for use when prescribed according to its labeling. However, it’s not unusual for the FDA to identify issues that need additional evaluation either at the time of initial approval or later, once the drug has been marketed. These issues are evaluated through the conduct of additional post-marketing studies.
These post-approval studies are vital to enhancing patient safety and public health. They may be needed to further characterize the use of the product in the therapeutic armamentarium. Additionally, post-approval studies can allow for further evaluation of a potential safety issue or better characterize risk factors for a known safety issue. Once a drug is approved, invariably a larger population and wider range of patients will use the drug than were studied before approval. With this larger patient experience, new potential safety issues may emerge that were not seen in the studies conducted prior to approval. And such issues may require additional evaluation after the drug is marketed and used by patients for a period of time.
The results from completed post-market studies provide additional information that can lead to safety labeling changes, support expanded use of a drug, or alleviate concerns about a potential drug risk. The FDA is always looking at opportunities to facilitate the conduct and completion of these studies to ensure that patients and providers have the most complete data about a drug to inform their treatment decisions.