Clinical Trials 101: Terminology
Clinical trials are foundational to medical research, driving innovation and paving the way for new treatments. However, the terminology can often be difficult to understand.
Join us for an exploration of essential clinical trial terms and definitions:
What is a Clinical Trial?
In a clinical trial, patients undergo specific interventions, such as medical products, procedures, or behavioral changes, according to a predefined plan or protocol. The goal of a clinical trial is to determine the safety and efficacy of the intervention by measuring participant outcomes.
What is a Protocol?
A protocol is a detailed study plan that outlines the objectives, methodology, and procedures of a clinical trial. It serves to ensure participant safety and guide researchers in answering specific research questions.
Phases of Clinical Trials:
Phase I: Phase I trials involve a small group of individuals (20 - 80) to evaluate the safety and determine the appropriate dosage of a new drug or treatment.
Phase II: Phase II trials expand the participant pool (100 - 300) to assess the effectiveness of the treatment for a specific condition or disease and establish therapeutic dosages for Phase III studies.
Phase III: Phase III trials involve large-scale testing with thousands of participants, ranging from 1,000 to 3,000 individuals. The objective of these trials is to confirm effectiveness, compare the treatment with standard or similar treatments, monitor side effects, and collect data for regulatory approval.
Phase IV: Phase IV trials occur after a treatment has received regulatory approval and is available to the public. These trials involve thousands of participants and focus on gathering additional information about the treatment's long-term safety and efficacy, and any rare or unexpected side effects that may emerge over time.
Expanded Access (Compassionate Use)/Single Patient Investigational New Drug (IND) Trials:
These trials provide access to investigational medical products (such as a drug or medical device) that are not yet approved for treatment. Expanded access is not clinical research and is not available for all interventions being tested. For patients who cannot join a clinical trial and have no other treatment options, expanded access may be an option, but requires intensive FDA and IRB approval processes.
Who are the Medical Professionals Involved in Clinical Trials?
Principal Investigator: The lead professional responsible for overseeing the scientific integrity of the study.
Oncologists: Physicians specializing in cancer treatment who manage day-to-day study elements.
Research Coordinators: Coordinators supporting oncologists in managing study logistics and patient care.
Laboratory Researchers and Scientists: Professionals analyzing study data behind the scenes.
Institutional Review Board (IRB): IRBs are review boards that safeguard the rights and welfare of human subjects. They review and approve research activities and provide oversight for ongoing research studies.
For additional resources, visit our FAQs page here.
For a comprehensive glossary of clinical trial terminology, visit clinicaltrials.gov’s study ‘Study Basics’ Glossary here.
