Each clinical trial defines who is eligible to take part in the study. Each trial must include only people who fit the patient traits for that study (the eligibility criteria), and will enroll people who have a specific disease or condition. Others enroll healthy people to test new approaches to prevention, diagnosis, or screening. So the FDA wants people from many different groups included in these studies.
In the past, most drug testing had been done on white men. This means that some groups, such as African Americans, Hispanics / Latinos, American Indians, Asians, Pacific Islanders and women, had not always been included in the tests done on drugs. But sometimes drugs work differently in these people than on white men. So FDA wants people from many different groups included in these studies.
What Happens in a Clinical Trial?
During a clinical trial, doctors and other healthcare providers might be part of your treatment team. They will monitor your health closely. You may have more tests and medical exams done than you would if you were not taking part in a clinical trial. Many studies require that neither the patient nor the doctor knows whether the patient is receiving the study treatment, the standard treatment, or a placebo (an inactive substance that looks like the drug being tested). In other words, some people may be getting no treatment at all.
Studies are done in phases to find different kinds of information. For example, Phase I clinical trials test new treatments in small groups of people for safety and side effects. Phase II clinical trials look at how well treatments work and further review these treatments for safety. Phase III clinical trials use larger groups of people to confirm how well treatments work, further examine side effects, and compare new treatments with other available treatments.
Phase II studies include more people than Phase I studies, and the people have a disease that the product is going to treat. Now scientists try to see how well the product works against the disease. If the product works, the study moves into Phase III. In Phase III large numbers of patients with the disease are included to see if the new treatment works as well as the standard treatment.
A Phase IV clinical research study occurs after a drug has been approved by the FDA. The drug may be compared with similar medications, it may be evaluated for additional patient populations, or it may be studied for any specific, unusual, or unexpected side effects.