Glossary of Clinical Trial Terms
ADVERSE REACTION: (Adverse Event):
Also known as side effects, adverse
reactions include any undesired actions or effects of the experimental drug or treatment.
Experimental treatments must be evaluated for both immediate and long-term side
A drug, device or biologic must be approved by a country’s regulatory
agency before it can be marketed. The approval process involves several steps
including pre-clinical (animal) studies, clinical trials for safety and efficacy, filing of a New
Drug Application (NDA) in the United States or Marketing Authorization Application
(MAA) in Europe by the manufacturer, regulatory agency review of the application, and
agency approval/rejection of application.
Any of the treatment groups in a clinical trial. Most randomized trials have two
“arms,” but some have three “arms,” or even more.
Baseline information is gathered at the beginning of a study from which
variations found in the study are measured. Baseline can also be described as a known
value or quantity with which an unknown is compared when measured or assessed.
Safety and efficacy of a drug are often determined by monitoring changes from the
When a point of view prevents impartial
judgment on issues relating to the subject
of that point of view. In clinical studies, bias is controlled by blinding and randomization.
BLIND, BLINDED or BLINDING:
A clinical trial is “blinded” if the participants are
unaware on whether they are in the experiment
al or control arm of the study. Blinding
may also be extended to the investigators so that their patient observations are less
likely to be biased by their awareness of the treatment the patient is receiving.
CASE CONTROL STUDY:
A scientific study that compares a group of people with a
disease (such as leukemia) to a similar gr
oup of people without that disease. This type
of study compares the levels of exposure (for example, radiation or chemical) each
group had before appearance of the disease.
Pertaining to or founded on observation and treatment of human participants
or patients, as distinguished from theoretical or basic science.
A medical researcher in charge of carrying out a clinical
CLINICAL RESEARCH ASSOCIATE (CRA):
Person employed by the study sponsor or
clinical research coordinator to monitor a clinical trial at one or more participating sites.
The CRA is responsible for ensuring all clinical studies are conducted according to study
protocol, within regulations and ICH guidelines.
CLINICAL RESEARCH COORDINATOR (CRC):
Site administrator for the clinical trial
who is responsible for coordinate administrative activities between field and home offices
staff, such as the collection of essential documents, distribution of supplies and site
selection. Also called research, study or health care coordinator, data manager,
research nurse or protocol nurse.
Clinical trials, also known as clinical studies, test potential treatments
in human volunteers or patients to see whether they should be further investigated or
approved for wider use in the general population. A treatment could be a drug, medical
device, or biologic, such as a vaccine, blood product, or gene therapy. Potential
treatments, however, must first be studied in laboratory models or animals to determine
its safety before they can be tried in people. Treatments having acceptable safety
profiles for the disease or condition and showing the most promise are then moved into
clinical trials. Clinical trials are an integral part of new product discovery and
development, and are required by all regulatory agencies (e.g., the Food and Drug
Administration (FDA) in the United States), before a new product can be brought to the
COMMUNITY-BASED CLINICAL TRIAL (CBCT):
A clinical trial conducted primarily
through primary care physicians rather than researchers at academic facilities.
A method of providing experimental therapeutics prior to final
regulatory agency approval for use in humans. This procedure is used with very sick
individuals who have no other treatment options. Often, case-by-case approval must be
obtained by the patient’s physician from the regulatory agency for “compassionate use”
of an experimental drug or therapy.
CONFIDENTIALITY REGARDING TRIAL PARTICIPANTS:
Refers to maintaining the
confidentiality of trial participants including their personal identity and all personal
medical information. The trial participants'
consent to the use of records for data
verification purposes must be obtained prior to the trial. The Informed Consent
Document will explain how personal health information and study data will be used in
accordance with pertinent data protection laws and regulations.
CONTRACT RESEARCH ORGANIZATION (CRO):
A commercial organization
contracted by a research and development organization to perform one or more
A specific circumstance in whic
h the use of certain treatments
are not allowed usually because they could be harmful or fatal.
A control is the standard by which experimental observations are
evaluated. In many clinical trials, one gr
oup of patients will be given an experimental
drug or treatment, while the control group is given either a standard treatment for the
illness or a placebo.
A control is a standard against which experimental
observations may be evaluated. In a controlled clinical trial, one group of participants is
given an experimental drug, while another group (i.e., the control group) is given either a
standard treatment for the disease or a placebo.
A clinical trial in which all participants receive both treatments,
but at different times. At a predetermined point in the study, one group is switched from
the experimental treatment to the control treatment (standard treatment), and the other
group is switched from the control to the experimental treatment.
DATA SAFETY MONITORING BOARD (DSMB):
A committee, independent of the
sponsor, composed of clinical research experts that reviews trial data while a clinical trial
is in progress to ensure that participants are not exposed to undue risk. A DSMB may
recommend that a trial be stopped if there are safety concerns or if the trial objectives
have been achieved and further continuing the study would not benefit the patients.
DATA SAFETY MONITORING PLAN (DSMP):
This plan is meant to assure that each
clinical trial has a system for appropriate oversight and monitoring of the conduct of the
trial. This oversight ensures the safety of the participants and the validity and integrity of
DECLARATION OF HELSINKI
: A series of guidelines adopted by the 18th World
Medical Assembly in Helsinki, Finland in 1964. The Declaration addresses ethical issues
for physicians conducting biomedical research involving humans. Recommendations
include the procedures required to ensure subject safety in clinical trials, including
informed consent and Ethics Committee reviews.
The characteristics of participant group or populations. This
could include data on race, age, sex and medical history, all of which can be relevant to
the clinical trial study findings.
An instrument, apparatus, implement, machine, contrivance, implant, in vitro
reagent, or other similar or related article, including any component, part or accessory,
that is used to diagnose, cure, treat, or prevent disease. A device does not achieve its
intended purpose through chemical action or metabolism in the body.
Refers to trials that are conducted to find better tests or
procedures for diagnosing a particular disease or condition. Diagnostic trials usually
include people who have signs or symptoms of the disease or condition being studied.
A clinical trial in which two or more doses of an agent (such
as a drug) are tested against each other to determine which dose works best and is least
A clinical trial design in which neither the participating
individuals nor the study staff knows which
participants are receiving the experimental
drug and which are receiving a placebo or another therapy). Double-blind trials are
thought to produce objective results, since the knowledge, expectations and biases of
the doctor and the participant about the experimental drug or treatment do not affect the
A modification of the effect of a drug when administered
with another drug. The effect may be an increase or a decrease in the action of either
substance, or it may be an adverse effect that is not normally associated with either
Whether a drug achieves its desired effect in the real world.
(Of a drug or treatment) the ability of a drug or treatment to produce a
beneficial result. A drug demonstrates efficacy if it is effective at the dose tested against
the illness for which it is prescribed.
Summary criteria for participant selection; includes inclusion
and exclusion criteria.
Based on observation or experience, not experimental data.
Overall outcome that the protocol is designed to evaluate.
The branch of medical science that deals with the study of incidence,
distribution and control of a disease in a population.
See institutional review board or "IRB" definition below
EUROPEAN MEDICINES AGENCY (EMEA):
The European regulatory agency
responsible for the scientific evaluation of applications for European marketing
authorization for medicinal products (centralized procedure). EMEA’s main mission is to
protect and promote public and animal health, through the evaluation and supervision of
medicines for human and veterinary use.
The medical or social standards determining
whether a person may or may not be allowed to enter a clinical trial. These criteria are
based on such factors as age, gender, pregnancy status, the type and stage of a
disease, previous treatment history, and other medical conditions. It is important to note
that inclusion and exclusion criteria are not used to reject people personally, but rather to
identify appropriate participants to ensure the integrity of the study and to keep them
Refers to any of the regulatory authority procedures, such as
compassionate use, parallel track, and treat
ment Investigational New Drug Application
(IND) that distribute experimental drugs to participants who are failing on currently
available treatments for their condition and also are unable to participate in ongoing
A drug that has been authorized for use
in a clinical trial but has not been granted marketing approval as a treatment for a
A clinical trial where a medical procedure or medicinal
product, previously developed and assessed through laboratory model or animal testing,
or through mathematical modeling is tested on human subjects for the first time.
FOOD AND DRUG ADMINISTRATION (FDA):
The U.S. Department of Health and
Human Services agency responsible for ens
uring the safety and effectiveness of all
drugs, biologics, vaccines, and medical devices. The FDA also works with the blood
banking industry to safeguard the nation's blood supply.
A medicine with the same active ingredient, but not necessarily the
same inactive ingredients, as a brand-name drug. A generic drug may be marketed only
after the original drug's patent has expired.
The Health Insurance Portability and Accountability Act of 1996 (HIPAA)
established national standards for electronic health care transactions and national
identifiers for providers, health plans, and em
ployers. It also addresses the security and
privacy of health data. All clinical trial data and activities performed by covered entities
must comply with HIPAA regulations.
A patient or healthy person participating in a research project.
A theory, supposition or assumption advanced as a basis for reasoning
or argument, or as a guide to experimental investigation.
Informed consent is the verification of a person’s willingness to
participate in a research project. Prior to enrollment into a clinical trial, researchers
inform participants about all relevant study
details. Participants are provided an informed
consent document that details all the import
ant study information including its purpose,
duration, risks, potential benefits, required procedures, and key contacts, and they will
be asked to sign this document if they agree to participate in the trial. The informed
consent document is not a contract. Participation in the clinical trial is voluntary and the
participant may withdraw from the trial at any time without penalty or loss of benefits to
which he/she is otherwise entitled. The research team actively maintains informed
consent throughout the trial by providing the participant with any new or developing
INFORMED CONSENT DOCUMENT:
A document that describes the rights of the study
participants, and includes details about the study, such as its purpose, duration, required
procedures, and key contacts. Risks and potential benefits are explained in the informed
consent document. The participant will be asked to sign this document if they agree to
participate in the trial. The informed consent document is not a contract. Participation in
the clinical trial is voluntary and the participant may withdraw from the trial at any time
without penalty or loss of benefits to which he/she is otherwise entitled.
INSTITUTIONAL REVIEW BOARD (IRB):
A committee of physicians, statisticians,
researchers, community advocates, and others that ensures that a clinical trial is ethical
and that the rights of study participants are protected. Every institution that conducts or
supports biomedical or behavioral research involving human participants must, by
federal regulation, have an IRB that approves and periodically reviews the research in
order to protect the rights of human participants.
INTENT TO TREAT:
Analysis of clinical trial results that includes all data from participants in the groups to which they were randomized even if they never received the treatment.
The generic name of the experimental treatment being studied.
Primary experimental treatments being studied. Types of treatments may include drug, gene transfer, vaccine, behavior, device, or procedure.
INVESTIGATIONAL NEW DRUG APPLICATION (IND):
The petition through which a drug sponsor requests the FDA to allow human testing of a new drug, antibiotic drug, or biological drug in a clinical investigation.
This includes an application for a biological product used in vitro for diagnostic purposes.
Testing or action inside an organism, such as a human subject or patient.
Testing or action outside an organism (e.g. inside a test tube or culture
MARKETING AUTHORIZATION APPLICATION (MAA):
An application submitted by a sponsor to the EMEA for approval to market a new drug (a new, non-biological molecular entity) for human use in Europe.
Systematic methods that use statistical techniques for combining results from similar studies to obtain a quantit ative estimate of the overall effect of a particular intervention or variable on a defined outcome. This type of analysis is typically hypothesis generating.
Clinical trial conducted according to a single protocol but at
more than one site, and, therefore, carried out by more than one investigator.
MULTIPLE-RISING DOSE STUDY:
see dose ranging study above.
NATIONAL INSTITUTES OF HEALTH (NIH):
Agency within the Department of Health and Human Services that funds research, conducts studies, and funds multicenter national studies.
NEW DRUG APPLICATION (NDA):
An application submitted by a sponsor to the FDA
for approval to market a new drug (a new, non-biological molecular entity) for human use
in interstate commerce in the United States.
An epidemiologic study that does not involve any
intervention, experimental or otherwise. Such a study may be one in which nature is
allowed to take its course, with changes in one characteristic being studied in relation to
changes in other characteristics. Analytical epidemiologic methods, such as case-control
and cohort study designs, are properly called observational epidemiology because the
investigator is observing without intervention other than to record, classify, count, and
statistically analyze results.
A drug prescribed for conditions other than those approved by a country’s regulatory agency.
OFFICE FOR HUMAN RESEARCH PROTECTIONS (OHRP):
The Office for Human Research Protections (OHRP) supports, strengthens and provides leadership to the nation’s system for protecting volunteers in research that is conducted or supported by the U.S. Department of Health and Human Services (HHS). OHRP provides clarification and guidance to research institutions, develops educational programs and materials, and promotes innovative approaches to enhancing human subject protections.
A clinical trial in which doctors and participants know which
treatment is being administered.
A drug category that refers to medications used to treat rare
diseases and conditions. Orphan drug status, provides a manufacturer specific
incentives to develop and bring such treatments to market.
An outcomes trial evaluates the effect of a treatment on
patients. Treatments may include medications or other therapies and outcomes may
include changes in disease status, morbidity or mortality.
A p-value demonstrates the likelihood that sample data do not adequately
represent the population from which they were drawn.
The accepted standard for a statistically significant p-value is <0.05, meaning that the likelihood that the result could occur by random chance is less than 5 in a hundred.
A parallel designed clinical trial compares the results of a
treatment on two separate groups of patients. The sample size calculated for a parallel
design can be used for any study where two groups are being compared.
Review of a clinical trial by independent experts. These experts review
the trials for scientific merit, validity, participant safety, and ethical considerations.
The study of how drugs interact with living organisms to produce a
change in function. Pharmacology deals with how drugs interact within biological
systems to affect function.
The processes (in a living organism) of absorption, distribution,
metabolism, and excretion of a drug or vaccine.
The science of collecting, monitoring, researching, assessing
and evaluating information from healthcare pr
oviders and patients on the adverse effects
of medications, biological products, herbalism and traditional medicines with a view to
identify new information about hazards associated with medicines and preventing harm
PHASE 1 CLINICAL TRIAL:
Sometimes called dosing studies, these trials may test
methods of administering the treatment (e.g. by mouth, injection, etc.) and how often, as
well as the safety of the treatment. These tria
ls usually involve a small number of healthy
PHASE 2 CLINICAL TRIAL:
These trials continue to test the safety of the treatment and
evaluate how well the treatment works. Phas
e 2 studies usually evaluate the treatment
in a specific condition. These trials usually involve 100-300 patients.
PHASE 3 CLINICAL TRIAL:
These trials compare the new treatment to the current
standard of treatment for a specific condition, establishing both efficacy and adverse
events. Participants are usually assigned to
either receive the new treatment or the
current standard. Phase 3 trials typically enroll large numbers of patients (1,000-3,000 or
many more) and may be carried out at hospitals and doctors’ offices nationwide.
PHASE 4 CLINICAL TRIAL:
Post-marketing studies to gain a greater understanding of
the treatment, including its risks, benefits, and optimal use.
A study, usually Phase 3, which presents the data used by regulatory
agencies to decide whether to approve a drug. A pivotal study will generally be well-
controlled, randomized, and whenever possible, double-blind.
A placebo is an inactive pill, liquid or powder that has no treatment value. In
clinical trials, a placebo is administered instead of an active drug or experimental
treatment to assess the experiment
al treatment’s effectiveness.
PLACEBO CONTROLLED STUDY:
A method of drug investigation in which an inactive
substance (a placebo) is given to one group of participants, while the drug being tested
is given to another group. The results obtained in the two groups are then compared to
see if the investigational treatment is more effective than the placebo in treating the
A physical or emotional change, occurring after an inactive
substance is taken or administered, that is not the result of any special property of the
substance. The change may be beneficial, reflecting the expectations of the participant
and, often, the expectations of the person giving the substance.
Experiments performed in the laboratory and in animals to
study a drug before it is tested in humans.
Conducted to find better ways to prevent disease in people who
have never had the disease or to prevent
a disease from returning. These approaches
may include medicines, vitamins, vaccines, minerals, or lifestyle changes.
A person responsible for the conduct of the clinical trial at
a trial site. If a trial is conducted by a team of individuals at a trial site, the investigator
who is the responsible leader of the team may be called the principal investigator.
A prospective study identifies subjects, applies a treatment
and follows them over time to measure their progress/outcomes relative to a pre-
determined set of criteria or endpoints.
A protocol is the study plan on which a clinical trial is based. Each trial is
carefully designed to safeguard the health of participants as well as answer specific
research questions. A protocol describes what types of people may participate in the
trial, the schedule of tests, procedures, medications, dosages, and length of the study.
QUALITY OF LIFE TRIALS (or Supportive Care trials):
Refers to trials that explore
ways to improve comfort and quality of life for individuals with a chronic illness.
A method based on chance by which study participants are
assigned to different treatment groups. This minimizes the differences among groups by
equally distributing people with particular charac
teristics among all the trial arms, thereby
avoiding “selection bias.” Randomization allows for researchers to comparably test
different treatments in similar groups.
A study in which participants are randomly (i.e., by chance)
assigned to one of two or more treatment arms of a clinical trial.
A quick-relief or fast-acting medication patients in clinical trials
may be given besides the investigational drug or control that can alleviate symptoms due
to disease or lack of efficacy of the study treatment. It acts quickly to stop symptoms, but
the effects are not long lasting.
A study in which investigators select groups of patients that
have already been treated and analyze data fr
om the events experienced by these
patients. These studies are subject to bias because investigators can select patient
groups with known outcomes.
The risk a treatment places on individual participants versus the
potential benefits of the treatment. The risk/benefit ratio may differ depending on the
condition being treated.
Refers to trials which test the best way to detect certain diseases
or health conditions.
Any undesired actions or effects of a drug or treatment. Experimental
drugs must be evaluated for both immediate and long-term side effects.
A study in which subject or patient is unaware of what
medication they are taking, while the physician does know.
A person or an organization that manages and finances a clinical trial.
A treatment currently in wide use by the medical community
and approved by a country’s regulatory agency considered to be effective in the
treatment of a specific disease or condition.
STANDARDS OF CARE:
Treatment regimen or management based on state of the art
The probability that an event or difference occurred by
chance alone. In clinical trials, the level of statistical significance depends on the number
of participants studied and the observations made, as well as the magnitude of
One versed in or engaged in compiling statistics.
An outcome used to judge the safety or effectiveness of a
A biomarker or endpoint that is intended to substitute for a
clinical endpoint. A surrogate endpoint is expected to predict a clinical endpoint or lack
A treatment-related adverse effect that may be detrimental to the recipient's
health. The level of toxicity associated with a treatment will vary depending on the
attributes of the treatment itself and the condition the drug is being used to treat.
TREATMENT INVESTIGATIONAL NEW DRUG (IND):
It makes promising new drugs
available to desperately ill participants as early in the drug development process as
possible. Treatment INDs are made available to participants before general marketing begins, typically during Phase 3 studies. To be considered for a treatment IND a participant cannot be eligible to
be in the definitive clinical trials.
Refers to trials which test new treatments, new combinations of
drugs, or new approaches to surgery or radiation therapy.