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Clinical Trials Q&A

What is a clinical trial?

A clinical trial (also called a study) is a test of a drug, therapy, surgical procedure, medical device, or of nutrition or behavioral changes in people. The purpose is to gather information to confirm that the drug, therapy, etc., is safe and effective on people.

This informative video by Clinical Trials Ontario captures the perspective of several stakeholders in clinical trials.

Who ensures that the trial is safe?

Government agencies delineate the guiding principles for clinical trials based on internationally accepted good clinical practice requirements. For example, the Tri-Council Policy Statement: Ethical Conduct for Research Involving Humans is a joint policy of Canada's three federal research agencies – Canadian Institutes of Health Research, Natural Sciences and Engineering Research Council of Canada, and Social Sciences and Humanities Research Council of Canada. This policy statement, called TCPS2, guides the conduct of research involving humans.

Who serves on the Research Ethics Board (REB)?

The REB is intended to be a cross-section of the community and is composed of medical and non-medical professionals, as well as lay people.

Who sponsors clinical trials?

Clinical trials are sponsored or funded by doctors, hospitals, foundations, voluntary groups, companies, and government funding agencies such as the Canadian Institutes of Health Research.

What are the phases of drug trials?

After a drug treatment is tested in the laboratory, it can progress to human testing. Such clinical trials are categorized as follows:
  • Phase I: Researchers test a new drug or treatment in 20-80 people to assess its safety, identify the maximum tolerated dose, find a safe dosage range, and identify possible side effects.

  • Phase II: The drug is tested on 100-300 people to see if it is effective, to further evaluate its safety, and to gather additional information regarding the safe dosage range.

  • Phase III: The drug is given to large groups of people (1,000-3,000) to confirm its effectiveness, monitor side effects, compare it to commonly used treatments and collect information that will allow the drug to be used safely.

  • Phase IV: Generally after a drug has been approved for use, investigators search for risks, benefits, and additional indications for use.

Why do people volunteer for clinical trials?

By taking part in clinical trials, you can try a potential new treatment that may (or may not) be better than the available treatments. Your participation may help people who encounter the same disease or condition in the future. It is important to remember that if you participate, you will be part of a group that is testing a treatment that has not yet received approval to be effective and safe.

How do I know if a trial is right for me?

You may volunteer for any trial appropriate to your condition. However, each clinical trial has strict eligibility requirements. The investigator (physician or other medical professional who runs the trial) will make sure you meet these requirements before accepting you in the trial.

What do I need to know before deciding to participate?

The study investigator should explain everything about the trial before you make a decision. That is called informed consent. Questions to consider in deciding if a clinical trial is right for you include:

What are the risks and benefits of participating in the study?

  • How do the alternative treatment choices compare to the research study?
  • What side effects, if any, can I expect?
  • What will I have to do as a research participant?
  • Who is in charge of the study?
  • Why was I invited to join the research study?
  • What is the study trying to determine?
  • How long will the study last?
  • How much of my time will it take?
  • What kinds of tests might I have to take?
  • Will I be hospitalized?
  • Will I be charged or paid for my participation in the study?
  • Can I still see my own doctor or therapist while in the study?
  • What happens in case of an emergency?
  • What happens after the study is complete? Will I be told the outcome?
  • How much privacy can I expect as a study participant?

What is informed consent?

Informed consent means you are given complete information about the study. Before you agree to participate, this information will be explained clearly in writing. If you choose to sign the informed consent form, it signifies that you were given this information and understand it. Informed consent also includes ongoing discussions regarding the risks and benefits of participating in a clinical trial.

What if I change my mind about participating?

Informed consent is not like a contract. You can leave the study at any time of your choosing and without any penalty. Just tell the investigator or study coordinator. You will still be able to have standard treatment appropriate for your disease or condition. The investigator conceivably might decide in your best interests to discontinue your participation in the trial.