Clinical Trials

Questions About Clinical Trials

What are clinical trials, and why are they important?
Clinical trials are research studies that test how well new medical approaches work in people. Each study answers scientific questions and tries to find better ways to prevent, screen for, diagnose, or treat a disease. People who take part in cancer clinical trials have an opportunity to contribute to knowledge of, and progress against, cancer. They also receive up-to-date care from experts.

What are the types of clinical trials?
There are several types of clinical trials:

Who sponsors clinical trials?
Government agencies, such as the National Cancer Institute (NCI) and other parts of the National Institutes of Health (NIH), the Department of Defense, and the Department of Veterans Affairs, sponsor and conduct clinical trials. In addition, medical institutions such as Yale Cancer Center, foundations, volunteer groups, and pharmaceutical companies, also sponsor clinical trials.

How are participants protected?
Research with people is conducted according to strict scientific and ethical principles. Every clinical trial has a protocol, or action plan, which acts like a "recipe" for conducting the trial. The plan describes what will be done in the study, how it will be conducted, and why each part of the study is necessary. The same protocol is used by every doctor or research center taking part in the trial.

All clinical trials at Yale Cancer Center must be reviewed and approved by the Human Investigations Committee (HIC). The Committee reviews the protocol to make sure the study is conducted fairly and participants are not likely to be harmed. The HIC also decides how often to review the trial once it has begun. Based on this information, the HIC decides whether the clinical trial should continue as initially planned and, if not, what changes should be made.

What are eligibility criteria, and why are they important?
Each study's protocol has guidelines for who can or cannot participate in the study. These guidelines, called eligibility criteria, describe characteristics that must be shared by all participants. The criteria differ from study to study. They may include age, gender, medical history, and current health status. Eligibility criteria for treatment studies often require that patients have a particular type and stage of cancer.

Enrolling participants with similar characteristics helps to ensure that the results of the trial will be due to what is under study and not other factors. In this way, eligibility criteria help researchers achieve accurate and meaningful results. These criteria also minimize the risk of a person's condition becoming worse by participating in the study.

What is informed consent?
Informed consent is a process by which people learn the important facts about a clinical trial to help them decide whether to participate. This information includes details about what is involved, such as the purpose of the study, the tests and other procedures used in the study, and the possible risks and benefits. In addition to talking with their doctor or nurse, patients receive a written consent form explaining the study. Patients who agree to take part in the study are asked to sign the informed consent form. However, signing the form does not mean patients must stay in the study. People can leave the study at any time-either before the study starts or at any time during the study or the follow-up period.

How are clinical trials conducted?
Clinical trials are usually conducted in a series of steps, called phases.

What are some of the benefits of taking part in a clinical trial?
The benefits of participating in a clinical trial include the following:

What are some of the possible risks associated with taking part in a clinical trial?
The possible risks of participating in a clinical trial include the following:

What are some questions people might ask their health care provider before entering a clinical trial?
It is important for people to ask questions before deciding to enter a clinical trial. Questions people might want to ask their doctor or nurse include the following:

The Study

Possible Risks and Benefits

Participation and Care

Personal Issues

Cost Issues

What happens when a clinical trial is over?
After a clinical trial is completed, the researchers look carefully at the data collected during the trial before making decisions about the meaning of the findings and further testing. After a phase I or II trial, the researchers decide whether to move on to the next phase, or stop testing the agent or intervention because it was not safe or effective. When a phase III trial is completed, the researchers look at the data and decide whether the results have medical importance.

The results of clinical trials are often published in peer-reviewed, scientific journals. Peer review is a process by which experts review the report before it is published to make sure the analysis and conclusions are sound. If the results are particularly important, they may be featured by the media and discussed at scientific meetings and by patient advocacy groups before they are published. Once a new approach has been proven safe and effective in a clinical trial, it may become standard practice.