• Treatment trials test experimental treatments, new combinations of drugs, or new approaches to surgery or radiation therapy.
• Prevention trials look for better ways to prevent a disease in people who have never had it, or to prevent a disease from returning. The approaches tested may include medicines, vaccines, vitamins, minerals, or lifestyle changes.
• Diagnostic trials are conducted to find better tests or procedures for diagnosing a particular disease or condition.
• Screening trials test the best way to detect certain diseases or health conditions.
• Quality of Life trials (or Supportive Care trials) explore ways to improve comfort and quality of life for individuals with a chronic illness.

Patients enroll in clinical trials for many reasons. These often include interest in advancing science and medical care, interest in gaining access to new, experimental treatments – especially if all other treatment options have failed – and also interest in learning more about their medical condition. Some patients may benefit from participating in a clinical trial if the investigational drug turns out to be effective, but there is no guarantee that a volunteer will receive any direct benefit.

By volunteering to participate in clinical trials, participants help advance what we know about medical interventions. In doing so, clinical trial participants can play an important role in getting new drugs and devices approved for use in treating other patients.

It is important to remember that the main purpose of clinical trials is to study new drugs or devices, or new uses of approved drugs or devices, and not to treat patients. Often, drugs or devices must be tested under very specific conditions, so not all patients with a given disease will be able to enroll in a clinical trial.

For each clinical trial, researchers develop eligibility criteria, such as age, sex, the type and stage of disease, previous treatment history, and other medical conditions. These criteria help to reduce the amount of variation in the study, without threatening the scientific integrity of the trial, by removing medical variations that might complicate the analysis of the results.

Not everyone who applies for a clinical trial will be accepted. Volunteers may be excluded based on the eligibility criteria and/or the number of participants needed by the researchers to collect enough information to determine the safety and effectiveness of an experimental therapy. Additionally, a clinical trial for a specific drug or device is typically conducted at a limited number of institutions. Patients who live too far away from a research center may not be able to participate. If a patient is not eligible for a clinical trial or there are none near where they live, the patient may be able to obtain access to an investigational drug outside of a clinical trial.

Even among patients who do participate in a clinical trial, some may be treated with the investigational drug, and some may be treated with a placebo (a substance not expected to have any real medical effect), often along with existing standard of care, or a different therapy for comparison. Drugs that are being tested in clinical trials may prove to be ineffective, or they may have unknown, sometimes serious, side effects.

The clinical trial process depends on the kind of trial being conducted. The clinical trial team includes doctors, research coordinators, and other health care professionals. They check the health of the participant at the beginning of the trial, give specific instructions for participating in the trial, monitor the participant carefully during the trial, and follow up after the trial is completed.

For trials, researchers, doctors, and other health professionals administer the clinical trials according to strict rules set by the Federal Office of Human Subjects Protections and the FDA. The federal government sets the rules to make sure that people who agree to be in studies are treated as safely as possible.

Some clinical trials involve more tests and doctor visits than the participant would normally have for an illness or condition. For all types of trials, the participant works with a research team. Clinical trial participation is most successful when the protocol is carefully followed and there is frequent contact with the research staff.

Clinical trials are sponsored or funded by a variety of sources:

The FDA and the Federal Office of Human Research Protections work to protect participants in clinical trials and to ensure that people have reliable information as they decide whether to join a clinical trial. The federal government has regulations and guidelines for clinical research to protect participants from unreasonable risks. Human research must be reviewed and approved by the Institutional Review Board (IRB).

An IRB is an independent committee of physicians, statisticians, community advocates, and others that ensures that a clinical trial is ethical and the rights of study participants are protected. Research investigators must regularly update the IRB on a study’s progress, including providing prompt reporting of any unexpected serious events. Complimenting the IRB’s responsibilities, the Office of Science and Research provides training for research personnel concerning study conduct and management, and also directly monitors human research.

Although efforts are made to control the risks to clinical trial participants, some risks may be unavoidable because of the uncertainty inherent in research studies involving new medical treatments. Researchers are required to give prospective participants complete and accurate information about what will happen during the trial, so that those interested in participating are fully informed before

Informed consent is the process of learning the key facts about a clinical trial before deciding whether to participate. It is also a continuing process throughout the study to provide information for participants.

To help someone decide whether to participate, the doctors, nurses, and research coordinators involved in the trial explain the details of the study. If the participant's native language is not English, translation assistance can be provided. Then the research team provides an informed consent document that provides written details that were discussed about the study, such as its purpose, duration, required procedures, and key contacts. Risks and potential benefits are also explained in the informed consent document.

This information enables those interested in study participation to make an informed decision about the level of risk they are willing to accept before they enter the trial. The participant then decides whether to sign the document.

Signing the document indicates the potential participant understands that the trial is research and understands its risks and possible benefits, that participation is voluntary, and also formally documents their consent to participate. Informed consent is not a contract, and the participant may withdraw from the trial at any time.

Anyone considering a clinical trial should know that there are both benefits and risks associated with participating.

Potential Benefits

Participating in well-designed and well-executed clinical trials is one way for eligible patients/volunteers to:

Possible Risks

There are generally known and unknown risks associated with clinical trials, such as:

The following questions might be helpful for the participant to discuss with the trial’s health care team. Some of the answers to these questions are found in the informed consent document.

After all participants have completed the study and all data collected from the trial are properly entered into the trial database, the data can be analyzed to determine the answers to the specific health questions posed by the study.

The types of questions to be answered depend on the purpose of the study. For drug trials, results from early-phase trials (Phase 1 and Phase 2) are used to determine whether a drug should go on to further testing, and to design the later-phase trials. Results from later-phase trials (Phase 3) are used by the FDA to determine whether a drug was shown to be safe and effective, and therefore approvable for marketing to the public.