Clinical Trials

All clinical trials have guidelines about who can participate. These guidelines, or criteria, are used to identify appropriate volunteers and ensure that they can participate safely. The criteria for a particular study may include such factors as age, gender, the type and severity of a disease or condition, previous treatment history, and other medical conditions or complications. Inclusion criteria are the factors that qualify volunteers to participate. Exclusion criteria disqualify people from the study. For food allergy trials, criteria may include the type of food allergy you have, whether or not you have a history of severe reactions or other conditions such as asthma, and so on.

Clinical trials are federally regulated, and strict safeguards are in place to protect participants' safety and ensure confidentiality. Informed consent is an important part of understanding and deciding to participate in a specific study. This process enables potential volunteers to learn the facts about the study before making the decision to participate. Informed consent also ensures that volunteers understand what is happening as the trial progresses.

To help you decide whether or not to participate, the doctors and nurses involved in the trial explain the details of the study. Then the research team provides an informed consent document that includes details about the study, such as its purpose, duration, required procedures, and key contacts. The informed consent document also explains the trial's benefits (such as the possibility of receiving the treatment after the trial is over, if it proves successful) and risks (such as potential side effects). If you decide to participate, then you sign the document. It is important to remember that informed consent is not a contract - you may withdraw from a clinical trial at any time.

Once you're enrolled in a study, you'll work with a team that includes doctors, nurses, and other health professionals. Team members will give you medical exams and take a detailed medical history at the beginning of the study. They will also monitor you throughout the trial and stay in touch after it is completed.

Keep in mind that participating in a clinical trial does not take the place of ongoing medical care by your primary physician and health care team. If you're thinking of volunteering for a clinical trial, be sure to speak with your doctor before you enroll. In addition, while you are enrolled in the trial, your doctor should be informed of the study's progress.

Clinical trials must meet rigorous safety standards, which are mandated by the federal government. The U.S. Food & Drug Administration (FDA) must approve the study design (also known as the protocol). These are detailed guidelines that describe the objectives and length of the trial, the type of patients who may participate, the schedule of tests and procedures, the medications and dosages to be studied, and so on.

In addition, every medical center has an Institutional Review Board (IRB), which is a panel of scientists and non-scientists that oversees clinical research and is responsible for approving the studies conducted at that institution. The IRB makes sure that the study meets the institution's standards, that participants have given consent to participate and are fully informed of their risks, and that researchers take appropriate steps to protect participants from harm. If the study is a multi-center trial - one that involves several medical centers - each institution's IRB must give its approval.

Before a therapy can be tested in humans, preclinical research is conducted in the laboratory. If these studies show promise, the sponsor - usually a pharmaceutical or biotechnology company or a research institution - requests permission to conduct clinical trials in people by submitting an Investigational New Drug Application (IND) to the FDA. If the FDA approves, the study will be conducted at one or more medical centers (usually large teaching hospitals).

Clinical trials are conducted in four phases:

• Phase 1 clinical trials test the experimental therapy in a small group of people (20-80) to evaluate its safety and identify side effects.
• Phase 2 studies test the therapy in a larger group of patients (100-300) to determine how well the treatment works and to further evaluate safety.
• Phase 3 trials involve a large number of participants (1,000-3,000). These studies confirm the treatment's effectiveness, monitor side effects, compare the experimental treatment to standard therapies, and collect information about safety. Successful completion of a Phase 3 study is usually the final step before the sponsor applies for FDA approval to market the therapy.
• Phase 4 trials are conducted after the treatment is approved by the FDA and marketed to the public. These studies provide more information about a therapy's long-term benefits and risks, its impact on patients' quality of life, its costs relative to its effectiveness, and how it compares to other therapies on the market.

It is important to keep in mind that, at any point in this process, a study may be discontinued if a treatment does not work or has problematic side effects.

If you're considering participating in a clinical trial, it's important that you consult your doctor and other members of your healthcare team first. If you decide to move forward and you meet the initial criteria for the study, you'll be invited to meet with the study's research team. You may want to write down your questions beforehand and bring a friend or relative along to the meeting. Remember, the more you know, the more comfortable you'll feel with your decision. Here is a list of questions that you may find helpful:

• What are the aims of this study?
• How long will the trial last?
• What therapies will be tested and how will they be administered?
• Why do researchers believe the treatment being tested may be effective? Has it been tested before?
• What kinds of tests are involved?
• Could the treatment or tests cause any pain or discomfort?
• Who will be in charge of my care?
• How will participants’ safety be monitored?
• What are the potential benefits and risks? How do they compare with the benefits and risks of my current treatment?
• Who is sponsoring the trial?
• How might this study affect my daily life?
• Do I have to pay for treatment or for any part of the trial? If so, will these expenses be covered by my insurance?
• Will I be reimbursed for non-medical expenses, such as transportation?
• What type of long-term follow up-care is part of this study?
• What happens if I am harmed by the trial?
• Can I opt to remain on this treatment, even after the trial ends?
• How will I know that the experimental therapy is working? Will the study results be provided to me?

For many years, clinical trials were conducted only in adults. To treat children, a common approach has been to use data from adults and adjust the dose of the medication according to a child's weight. But children are not simply small adults. Many factors affect the way they respond to treatments, including the growth and maturation of their organs, changes in metabolism throughout infancy and childhood, and changes in body proportion. In recent years, through a combination of new legislation and incentives for manufacturers, the number of pediatric clinical trials has increased. The FDA applies strict guidelines to children's participation in these studies. For more information, visit the NIH’s Children and Clinical Studies site.