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Clinical Trials

What is a clinical trial?

Clinical trials are research studies in which people help doctors and researchers find ways to improve health care. Each study tries to answer scientific questions and to find better ways to prevent, diagnose, or treat disease.

The purpose of a clinical trial is to find out whether a medicine or treatment regimen is safe and effective for the treatment of a specific condition or disease. Clinical trials compare the effectiveness of the study medicine or treatment against standard, accepted treatment, or against a placebo if no standard treatment exists.

What are the phases of a clinical trial?

A medicine or treatment regimen must go through three phases before it is approved for use by the U.S. Food and Drug Administration (FDA).

  • Phase I: A new medicine is tested for the first time on a small group of healthy people or people with specific conditions or diseases. Researchers evaluate the safety of the medicine or treatment, the best dose or schedule to use, and what types of side effects occur. During phase I trials, all of the people involved in the study (patients, doctors, and researchers) know what medicine is being used. These are called nonrandomized, nonblinded studies.
  • Phase II: The medicine or treatment is tested on a larger group of people with specific conditions or diseases. This phase helps researchers find out how well a medicine or treatment regime will work to treat a particular problem. Phase II trials are also usually nonrandomized, nonblinded studies.
  • Phase III: The medicine or treatment regimen is tested on even larger groups. The medicine is studied to find out how well it works compared with standard treatment or placebo and whether it improves specific areas in your life, such as how well you are able to keep up with your usual routine. Most medicines that reach phase III trials will be considered for FDA approval. During phase III trials, participants receive the study medicine, a placebo, or the standard treatment. Neither the participants, the doctors, or the researchers know which person is getting which medicine. These are called randomized and double-blinded studies.
  • Phase IV. Medicines are also studied after they are approved to find new uses for the medicine, different ways to administer it, or additional safety information. For example, a medicine may be studied to see how well it works for a specific population, such as adults over the age of 65 or a certain racial group.

New combinations of approved medicines can be studied in phase II, phase III, or phase IV trials.

How can I find out about clinical trials?

The U.S. National Institutes of Health, through its National Library of Medicine, has developed ClinicalTrials.gov to provide information about clinical research studies to patients, family members, and members of the public. You can contact this service on the Internet at www.ClinicalTrials.gov. Or you can get information over the phone by calling 1-888-346-3656 or (301) 594-5983. There may or may not be a clinical trial available in your area that relates to your particular disease or stage of disease.

What To Expect After Treatment

If you are accepted into the clinical trial and you give your consent to participate, you will be given a structured program to follow. You will have a schedule of tests, doctor appointments, and treatments. You may also be asked to keep a diary of your experience during this time. Be sure to carefully follow instructions. If you do not know what you are supposed to do next, call your doctor. Or call the person responsible for your trial.

Doctors, nurses, social workers, and other health professionals may be part of your treatment team. Your treatment team may continue to check on you after your trial is over.

Typically, all of the costs of your treatment are covered by the organization sponsoring the clinical trial.

Why It Is Done

Why are clinical trials important?

Clinical trials are important because they compare new treatments with accepted treatments. They allow researchers to find out whether a new treatment works better than accepted treatments. The new treatment might work as well as or better than standard therapies. And the new treatment might have fewer or better-tolerated side effects. On the other hand, the new treatment might not work as well or might cause more side effects than standard treatments.

Clinical trials help pharmaceutical or biotechnology companies develop medicines that are safer and more effective with fewer side effects. Clinical trials also help these companies decide whether it is worthwhile to seek approval from the U.S. Food and Drug Administration (FDA) for a certain medicine. If a medicine does not work as well as standard therapy, then the FDA is not likely to approve it.

Clinical trials are also important in finding treatments if no standard treatment exists. Clinical trials help show how well the new treatment works and what side effects it may cause.

How do clinical trials work?

Your doctor will help you find out whether you are eligible to take part in a clinical trial. The company sponsoring the trial will have a very strict set of criteria that all participants must meet. If you meet the criteria, you may be "randomized" to either the new medicine, a medicine that is considered standard therapy, or a placebo. That means that a computer is used to randomly assign you to one of the treatments, and neither you nor your doctor knows which treatment you are getting. But not all clinical trials randomize people. And if you have a serious disease, such as cancer, you will not be given only a placebo, unless no effective treatment is known.

Every clinical trial in the United States must be approved and monitored by an institutional review board (IRB) to make sure the risks are as low as possible and worth any potential benefits.

After you are accepted by the clinical trial and you give your consent to take part, you will be given a structured program to follow. You will have a schedule of tests, doctor appointments, and treatments. You may also be asked to keep a diary of your experience during this time.

Sometimes the group sponsoring your trial will be responsible for the cost of the medicine as well as the costs of medical tests that are required while you are in the trial. Clinical trials usually require you to have more medical tests than you would have if you were not in the trial. But in other trials, the cost of the medicine and only some of the medical tests will be covered. Some studies will reimburse you for the cost of traveling to and from your medical visits.

What happens when the clinical trial is finished?

After a clinical trial is completed and the data collected is studied, the FDA decides whether to approve continued development of the medicine. If the medicine that you received remains in development, you may be able to receive additional doses as an extension of the study.

If the results of the clinical trial show that the new medicine or combination of medicines works much better than standard treatment, the new medicine may become available to the general public.

How Well It Works

Clinical trials compare new treatments to accepted treatments or to a placebo if no standard treatment exists. They allow researchers to find out whether a new treatment works better than accepted treatments. The new treatment might work as well as or better than standard treatment. And it might have fewer or better-tolerated side effects. On the other hand, the new treatment might not work as well or might cause more side effects than standard treatments.

Risks

You should be fully informed about the possible risks and benefits of the trial before you consent to participate.

What are the risks of clinical trials?

  • The new treatment may not work as well as standard treatments.
  • You may experience unpleasant, serious, or even life-threatening side effects from the treatment.
  • The treatment may not work for you.
  • The trial may require more of your time than standard treatment. You may have to:
    • Make more trips to the study site.
    • Have more treatments.
    • Receive your treatment in a hospital.
    • Take more medicine more frequently or at rigidly prescribed times.
    • Keep a written diary of your experience.

How is my safety protected?

Every clinical trial in the United States must be approved and monitored by an institutional review board (IRB) to make sure the risks are as low as possible and are worth any potential benefits.

The ethical and legal codes that apply to medical practice also apply to clinical trials. Most clinical research is regulated by the U.S. government, with specific rules to protect the participants. Clinical trials follow a carefully controlled study plan (protocol) that explains what everyone will do in the study. During the clinical trial, researchers report the results of the trial at scientific meetings, to medical journals, and to government agencies. Your name will remain secret and will not be mentioned in these reports.

What To Think About

Participation in a clinical trial is voluntary. No one can force you to participate. You should be fully informed about the possible risks and benefits of the trial before you consent to participate. If you choose not to take part, you will be offered the standard therapy for your disease.

Your taking part in a clinical trial may not benefit you directly. But in the future it may help other people who have the same disease.

Complete the special treatment information form (PDF)form.gif(What is a PDF document?) to help you understand this treatment.

By Healthwise Staff
Primary Medical Reviewer E. Gregory Thompson, MD - Internal Medicine
Specialist Medical Reviewer Michael Seth Rabin, MD - Medical Oncology
Last Revised October 31, 2011

WebMD Medical Reference from Healthwise

Last Updated: October 31, 2011
This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.

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