National Marrow Donor Program



What Is a Clinical Trial?

New medical treatments must be proven safe and effective before they can be offered to a large number of patients. New treatments are tested through clinical trials, a series of research studies using a limited number of patients. Any new type of treatment can be tested in a clinical trial. For example, when doctors use a marrow or cord blood transplant to treat a disease not usually treated with a transplant, that transplant is usually done as part of a clinical trial. Many transplant patients take part in clinical trials that test drugs used prior to transplant or to stop infection or fight graft-versus-host disease (GVHD) after transplant.

Most patients who receive an unrelated donor transplant have the option of taking part in a clinical trial at some time during their treatment. If you are thinking about being in a clinical trial, you should learn all you can about the trial you are considering. You should also learn about how clinical trials work.

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Clinical trials phases

There are three phases of clinical trials: Phase I, Phase II and Phase III. New drug treatments often begin with testing in a lab. Then they go through a Phase I trial, a Phase II trial, and finally a Phase III trial. If the trial results are good, the drug or other treatment may then be approved for use in the general public. In the United States, the Food and Drug Administration (FDA) decides whether to approve most drugs or treatments. Some types of treatment may not require all the phases of testing before being approved.

  Phase I Phase II Phase III
Description A Phase I trial is the first test of a new treatment to see if it is safe to use in people. The new treatment is tested because it showed promise in lab tests. Once a treatment is found to be safe (often in a Phase I trial), it can be tested to see if it helps patients. A Phase III trial tests a treatment that has been shown to help some patients (often in a Phase II trial). It usually compares a newer treatment to the standard or best known treatment.
Goals Learn:

Whether the treatment is safe

The best way to give the treatment (for example, as a pill or a shot)

The right dose — the amount that causes the fewest side effects 		Learn:

Whether the treatment works

Whether there are any less common side effects, which may appear when more patients get the treatment 		Learn:

Whether the new treatment is better than, as good as or worse than the standard treatment

Phase III trials may be more complex and look at more aspects of treatment than Phase I or II trials.

Number of Patients Often 20-30 Often 100 or more Several hundred to several thousand
What to Expect Patients often have many physical exams and tests (blood tests, for example) so doctors can find out how the treatment affects them. This may take a lot of time. Patients often have many physical exams and tests (blood tests, for example). This may take a lot of time. Phase III trials are usually randomized. This means half the patients in the study are chosen at random to get the newer treatment. The other half get the standard treatment. Patients and doctors do not decide which treatment the patient gets. As in Phase I and II trials, patients may have many physical exams and tests that may take a lot of time.

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Things to think about

If you decide to take part in a clinical trial, you should understand that:
  • The treatment being tested may or may not help you. You may get better, you may see no change or you may get worse.
  • Your participation helps doctors learn more about the treatment being tested. This knowledge may help many patients in the future. It may not help all the patients who are in the trial.
  • Some trials offer experimental treatments that you cannot receive outside the trial. Other trials compare standard treatments that you may be able to receive without being in the trial.
  • In a randomized trial, you may receive the treatment being tested or you may receive the standard treatment. You will not know ahead of time which treatment you will receive.

Randomized trials

In a randomized trial, half the patients are chosen at random to get the treatment being tested. They are called the treatment group (or investigational group). The other half receive the standard treatment. They are called the control group. Doctors compare the outcomes of the treatment group to the control group.

If you take part in a randomized trial, you and your doctor will NOT decide which group you are in. You are assigned to a group randomly, much like the toss of a coin. You have a 50/50 chance of being in either group.

In some studies, you will not know which group you are in. These are called blinded studies:
  • In a single-blind study, patients do not know whether they are in the treatment group or the control group.
  • In a double-blind study, neither the patients nor their doctors know which group they are in.

The purpose of blinded studies is to make sure the results are not biased by anyone's hopes for a certain treatment. Whichever group you are in, you will get the best care possible.

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Patient safety

Clinical trials must follow rules that protect patients' safety. In the United States, if the trial is funded by the federal government, these rules are made by the Office of Human Research Protections. (This office is part of the U.S. Department of Health and Human Services.) If the trial is for a drug or other product that must be approved by the FDA, then doctors must get permission from the FDA before starting a clinical trial.

Each clinical trial is also watched closely by an institutional review board (IRB). The IRB reviews the trial to be sure that it is ethical and that the rights of people who take part are protected. The IRB also monitors the trial to be sure the rules are followed. IRB members are experts from medical and non-medical communities. Members include doctors and people from other professions, such as ethical experts, teachers and religious leaders.

Throughout the trial, doctors make reports to the FDA and the IRB. The FDA and/or the IRB can stop a trial at any time to protect the people in it. They will stop the trial if any unexpected risks, such as dangerous side effects, are found.

The FDA and the Office of Human Research Protections require that patients give informed consent before joining a clinical trial. Informed consent means that the patient has been told about and understands the possible risks and benefits before agreeing to be in the trial.

Your rights and safety
You may be nervous at the idea of being part of the study of an experimental treatment. No one knows ahead of time whether the treatment being tested will help you, make no difference or even make you worse. However, before any treatment is tested in people, it has been studied carefully in a lab to see if it might be helpful to patients.
  • The safety of patients in clinical trials is important to the researchers and doctors involved. Your doctors will give you the best care they can.
  • If you are in a Phase III randomized trial, you will get one of the treatments being compared. Doctors do not know yet whether one treatment is better than the other.
  • You are a volunteer. You have the right to drop out of a clinical trial at any time.
  • You can continue to receive treatment even if you drop out of the trial. This right must be explained to you before you give informed consent.




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