Investigational Review Committee: Clinical Trials

About Clinical Trial and Clinical Research
Types of Clinical Trials
Research Protocols
Phases of Clinical Trials
Investigational Drugs
Protocol Review
Informed Consent

About Clinical Trials and Clinical Research

Clinical Research, also known as clinical trials or clinical studies, is medical research that involves people. Individuals volunteer to participate in carefully conducted investigations that ultimately uncover better ways to treat, prevent, diagnose and understand human disease.

Clinical research includes trials that test new treatments and therapies as well as long–term natural history studies, which provide valuable information about how disease and health progress. Clinical research also encompasses studies of interdisciplinary practices, scientific evaluation and qualitative investigation of patients and EBP topics.  

Types of Clinical Trials

The types of clinical trials include the following: 

  • Treatment trials that test new 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 the disease or to prevent the disease from returning. Better approaches may include medicines, vaccines, or lifestyle changes, among other things.
  • Diagnostic trials determine 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 and measure ways to improve the comfort and quality of life of people with a chronic illness

Research Protocols

Clinical research on drugs, devices or procedures is conducted according to a plan known as a protocol. The protocol is carefully designed to safeguard the participants’ health and answer specific research questions. A protocol describes the following: 

  • Who is eligible to participate in the trial
  • Details about tests, procedures, medications, and dosages
  • The length of the study and what information will be gathered

A clinical study is led by a principal investigator, who is often a doctor, but can be any professional on the health care team. Members of the research team regularly monitor the participants’ health to determine the study’s safety and effectiveness.

Phases of Clinical Trials

Clinical trials are conducted in "phases." The trials at each phase have a different purpose and help researchers answer different questions. Not all research studies are conducted in all four phases.

  • Phase I trials—Researchers test an experimental drug or treatment in a small group of people (20–80) for the first time. The purpose is to evaluate its safety and identify side effects.
  • Phase II trials—The experimental drug or treatment is administered to a larger group of people (100–300) to determine its effectiveness and to further evaluate its safety.
  • Phase III trials—The experimental drug or treatment is administered to large groups of people (1,000–3,000) to confirm its effectiveness, monitor side effects, compare it with standard or equivalent treatments, and collect information that will allow the experimental drug or treatment to be used safely.
  • Phase IV trials—After a drug is licensed (approved by the FDA) or treatment is launched, researchers track its safety, seeking more information about a drug or treatment’s risks, benefits, and optimal use. These long–term studies involving large groups of participants continue to see if any unexpected side effects occur in a small percentage of individuals.

Investigational Drugs

Most new drugs have to be evaluated in three separate phases before being approved by the U.S. Food and Drug Administration (FDA). Investigational drugs have not been approved by the FDA, or they are drugs that the FDA has approved for a different purpose. Clinical trials are a necessary step in that process. 

Bench to Bedside
Ideas for better treatments or innovations in patient care often begin in the laboratory and must follow a long, strictly controlled process to become available to patients and affect medical care.

In the laboratory
Medical research often begins at the cellular or molecular level, in the laboratory. Basic research spans a vast array of experiments to determine what causes disease. Examples of past and present research that has increased scientific knowledge about health include:

  • Advances in immunotherapy
  • Improved cancer treatments based on breakthroughs in research into how tumor cells develop
  • Innovations using yeast to produce human sugar structures in antibodies to develop cancer-fighting drugs

From "bench to bedside"
An experiment that is considered a success in the lab (at the "bench") needs to make the transition to patient care (to the "bedside"). Often called a translational study, this part of medical research is the ultimate destination of the journey from the lab to clinical medicine: treating the patient. A translational study is a step between basic research findings and their application to clinical studies with human participation in the trials. Animal studies or early Phase I clinical trials, also known as "proof of principle" or "proof of concept," are examples of translational research

Protocol Review

Each clinical trial in the United States must be approved and monitored by an Institutional Review Board/Committee (IRB/IRC) to ensure that the risks are minimal and are worth any potential benefits. An IRB/IRC is an independent committee that consists of physicians, other health-care professionals, administrative staff, statisticians, and members of the community who ensure that clinical trials are ethical and that the rights of participants are protected. Federal regulation requires all institutions in the United States that conduct or support biomedical research involving people to have an IRB/ IRC initially approve and periodically review the research. 


Clinical trials can be sponsored or funded by various organizations or individuals, including physicians, foundations, medical institutions, voluntary groups, and pharmaceutical companies, as well as federal agencies such as the National Institutes of Health, the Department of Defense, and the Department of Veterans Affairs. Trials can occur at sites as varied as hospitals, universities, doctors’ offices, or community clinics.  

Informed Consent

Informed consent is the process of providing potential participants with the key facts about a clinical trial before they decide whether to participate. The process of informed consent (providing additional information) continues throughout the study. To help someone decide whether or not to participate, members of the research team explain the details of the study. Translation or interpretive assistance can be provided for participants with limited English proficiency. The research team provides an informed consent document that includes details about the study, such as its purpose, duration, required procedures, and who to contact for further information. The informed consent document also explains risks and potential benefits. The participant then decides whether to sign the document and participate in the study. Informed consent is not a contract. Volunteers are free to withdraw from the study completely or to refuse particular treatments or tests at any time. Sometimes, however, this will make them ineligible to continue the study. It is essential that the informed consent be written in language that is easy to understand and that medical terms are defined for participants.

Source: National Institutes of Health


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