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Glossary of terms

When these terms appear in our Clinical Trials Data and Information Sharing webpages, they may be interpreted per the definitions provided below.

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Adverse event

An unfavorable medical occurrence that happens during a clinical trial. This sign, symptom or disease may or may not be associated with treatment being studied.

Arm assignment

The assignment of a group or subgroup of participants in a clinical trial to receive interventions, or no interventions, as detailed in the study protocol.


A procedure (e.g. a blood test, scan, etc.) implemented to generate data required by the clinical trial.


A drug that is produced from living organisms or may contain components of living organisms. A biologic targets the part of the immune system that causes inflammation.


A term used when patients or investigators are unaware of the treatment being received. This approach helps to reduce possible bias that could affect trial results. After the trial ends, the Sponsor will unblind the patient or investigator to share which treatment was received during the clinical trial.

Clinical trial

A research study conducted in human volunteers to answer specific health questions. Interventional trials determine whether experimental treatments or new ways of using known therapies are safe and effective under controlled environments.


A group or subgroup of participants in a clinical trial that are observed over time.


Also known as the standard treatment used for the condition, it is typically compared against the investigational treatment during the course of the clinical trial. The purpose of a controlled study is to show how well the investigational treatment works compared to the current approved treatment.


A double-blind trial helps to improve the results of a clinical trial by preventing bias. In this type of trial, the patient does not know if they are receiving the investigational treatment, standard treatment or a placebo. The treating physician is blinded to the treatment assignment along with the patient.


A measure of how well a treatment works.

Eligibility criteria

A set of guidelines for who can or cannot participate in a trial. These guidelines help to define the specific characteristics of volunteers who can or cannot participate since there can be differences among patients with the same disease.


Food and Drug Administration. A government agency within the U.S. Department of Health and Human Services that oversees the Nation's public health by making sure that human drugs, vaccines, biological products, medical devices, and any products that give off radiation are safe, effective, and secure.


In medicine, a condition or disease that makes a particular treatment advisable.


A natural reaction that the body creates to protect itself from harm, such as an infection, injury or toxins. Inflammation can occur either inside or on the body. On the body, affected areas may become red, swollen and painful and feel hot or warm to the touch.

Inflammatory disease

A disease characterized by inflammation, where the body’s immune system kicks in to protect itself from a perceived threat. This threat could be infection from outside factors like bacteria or a virus.

Informed Consent

A process used when a person is interested in learning more about a clinical trial. The purpose of informed consent is to protect the person and potential participant. During this process, the research team will go over details of the clinical trial with the potential participant and answer any questions or concerns that person may have. The person will sign this document to officially provide consent to participate if they decide to take part in the trial. The informed consent document is not a contract and if signed, the participant can withdraw from the trial at any time.

Institutional Review Board (IRB)

An administrative body of doctors, scientists, researchers, and members of the community this is established to protect the rights of human research participants and to minimize risk in a clinical trial.


A treatment or medicine that is used to alter and treat a specific condition or illness.

Investigational study

A clinical trial where an investigational, or experimental, treatment is studied to see if it can improve a certain disease or condition.

Investigational treatment

The drug being studied in a clinical trial  to see if it can improve a certain disease or condition.

Observational study

A research study that observes the effect of health outcomes in participants over the course of their routine care. Participants may receive treatments, but the investigator does not assign an experimental treatment.

Outcome measure

A tool or measure used to assess a patient’s current status. In clinical trials an outcome measure (endpoint) evaluates the impact an interventional treatment has on a participant.


An individual who consents to participate in a clinical trial or study.


A profile that reflects the process of absorption, distribution, metabolism, and excretion of a treatment. In the human body, it reflects what the body does to the drug.


A stage in the process of drug development. There are four phases:

  • Phase I: Consists of a small number of healthy volunteers and evaluates the treatment’s overall safety including the safest dose of the treatment.
  • Phase II: Consists of a small group of people with the disease to determine the most effective dosages. Information about the treatment’s safety, side effects and potential risks are also collected.
  • Phase III: Data collected is used to study if the treatment is effective, safe and better than what is already available for use. The treatment is usually compared to a placebo or control.
  • Phase IV: After a treatment has reached the market, additional trials are performed to collect additional information about the best use of the treatment.


A substance that has no therapeutic effect and is sometimes used to as a control in testing new treatments.

Preclinical studies

The early stage of development that examines the safety, toxicity and pharmacokinetics of the investigational treatment.  These tests are typically carried out in laboratory animals and required before clinical trials can begin.

Randomization number

A unique number assigned to each randomized patient by chance. In a clinical trial this number is used to identify individuals but maintain anonymity.

Screening visit

The first visit to the site of a clinical trial where a potential trial participant meets with the research team to discuss trial information, informed consent and any related questions or concerns. Eligibility is evaluated by the research team and if all parties agree, informed consent is signed. The participant often undergoes a physical exam and tests, reviews their medical history and if they qualify, the next baseline visit is scheduled.

Serious adverse event

Any untoward medical event or reaction in a clinical trial that results in death or is life-threatening.

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