Interventional studies are where participants are assigned to groups that receive one or more treatments (interventions) or no treatment. Researchers evaluate the outcomes. The group you are assigned to is determined by the study’s protocol. Observational studies are where individuals are observed, or certain outcomes are measured. No attempt is made to change the outcome. For example, no treatment is given. Expanded Access is a program (EAP) that provides investigational therapy that is not available in a clinical trial. It is for patients who have already tried all additional therapies and treatment options. Investigational medicines that are not yet approved by the U.S. Food and Drug Administration (FDA) may be included in these studies and require approval by the doctor and the company providing the medicine.