Clinical Trials Common Terms

Types of Clinical Trials

• 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. Approaches may include medicines, vaccines, or lifestyle changes.
• Screening trials test new ways for detecting diseases or health conditions.
• Diagnostic trials study or compare tests or procedures for diagnosing a particular disease or condition.
• Treatment trials test new treatments, new combinations of drugs, or new approaches to surgery or radiation therapy.
• Behavioral trials evaluate or compare ways to promote behavioral changes designed to improve health.
• Quality-of-life trials (or supportive-care trials) explore and measure ways to improve the comfort and quality of life of people with conditions or illnesses.

Clinical Trial Phases: Cancer clinical trials are structured into four different phases.

• Phase I: Test the safety and dosage of a new cancer treatment on a small group.
• Phase II: Evaluates the effectiveness of a drug and further assesses safety with a larger group.
• Phase III: Compares the new cancer treatment to the current standard treatment. Further testing is done with multiple larger groups to confirm its effectiveness and monitor side effects.
• Phase IV: Monitors long-term effectiveness and safety after FDA approval. Cancer researchers may also evaluate the use of the new drug in combination with other treatments. Studies involve thousands of people.

Blind Study: When trial participants don’t know if they are getting the treatment being tested or the placebo

Double Blind Study: When neither the participants nor the researchers know who is getting treatment being tested or the placebo

Eligibility: The rules that decide who can or cannot join a study

Informed Consent: When a person is given all the important information about a study and declines or agrees to join the study

Placebo: A substance or treatment that looks like the real one but has no active medicine; placebos are used for comparison to measure the effectiveness and safety of the new drug

Principal Investigator: The main researcher in charge of running the study

Protocol: The rulebook or plan for a clinical trial that tells the researchers what to do, how to do it, who can join, and how to keep everyone safe