Clinical Trials

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How Clinical Trials Work

Studies must follow strict scientific standards to make sure study participants are safe and that the results are reliable.

A few types of organizations can lead or sponsor clinical trials. The sponsor provides the overall support, and could include pharmaceutical or biotechnology companies, university medical centers, non-profit organizations, or government agencies.

Interventional Clinical Trials

For interventional clinical trials, people who meet certain criteria are assigned to a drug, treatment, or another intervention to find out how well a treatment works.

Phases of Interventional Clinical Trials

Interventional clinical trials are often categorized into phases, depending on how much is already known about the intervention and what the sponsor hopes to achieve.

Phase I

A new drug or treatment is given to a small group of people (often healthy volunteers who do not have the intended disease) to evaluate its safety and identify side effects.

Phase II

A larger group of people with the disease will receive the treatment to see if it the treatment has the intended effect.

Phase III

A much larger group of patients will receive the treatment to confirm its effectiveness and safety.

Phase IV

Clinical trials are sometimes conducted after the treatment has been approved for use to gather more information on its longer effects on much larger numbers of people with the disease.

Observational Trials

For observational trials, the people participating are observed to find out how they progress over time. Observational trials are often called registry trials or patient registries.
Most of the clinical trials conducted in Canada are Phase II, Phase III or Phase IV clinical trials.

More Clinical Trials Details

Getting Involved in a Clinical Trial

Participating in a clinical trial is always voluntary and should be carefully considered and discussed with your family, your doctor and your caregivers before deciding to take part. The decision to participate should only be made with a good understanding of any risks, potential benefits, obligations or time commitments that may come from enrolling, as well as any alternatives for you if you choose not to participate.
If you are offered the choice to participate, the risks and potential benefits will be explained in an “informed consent,” usually as a written document which you will be asked to sign. Even if you do sign, you may still withdraw from a study at any time, even if the study is not over.

Making sure Clinical Trials are Safe

All studies of new drugs, biological agents, or medical devices are reviewed and approved by Health Canada before patients can be enrolled (or by the US Food and Drug Administration if the study is conducted in the United States). All studies must also be reviewed and approved by a Research Ethics Board (REB), otherwise known as an ethics committee, or institutional review board (IRB) made up of doctors, researchers, and members of the community. Their role is to make sure the study is ethical, and the rights and welfare of participants are protected. Their job includes reviewing the informed consent document and making sure the risks are as small as possible.