What are Clinical Trials? | Risks & Benefits | Phases of Clinical Trials | Types of Clinical Trials | Informed Consent | Common words used to describe Clinical Trials | Useful links
Disclaimer: This list of clinical trials is for information purposes only. This list is not intended to be exhaustive; there may be other ongoing clinical trials and recruitment status may change without warning. Always discuss any clinical trial or treatment plan with your physician and/or health care provider.
What are Clinical Trials?
A clinical trial or study is a carefully controlled way to research the effectiveness and safety of new treatments. By the time a treatment is ready for clinical trials, it has already undergone exhaustive testing in the laboratory and in studies with animals. Clinical trials themselves are conducted under the close supervision of doctors and other research professionals, and have been vetted by Health Canada. The trial is also reviewed by a Research Ethics Board (REB), an independent group of research professionals. The REB ensures that the trial meets the highest ethical standards and is conducted safely.
A common myth is that clinical trial volunteers are guinea pigs, or that clinical trials are used as a last resort. This is not true. If your doctor has recommended a particular clinical trial to you, then it may be the best option for your particular situation, or stage or type of cancer.
You can learn about clinical trials in your region at www.canadiancancertrials.ca and www.clinicaltrials.gov. If you would like to participate in a clinical trial or learn more about whether a specific trial would be right for you, discuss it with your healthcare team. Ask them any questions you have, as they can best advise you about your treatment plan and options.
Some risks and benefits will be unique to your specific clinical trial, but some factors are common across all trials. When you participate in a clinical trial, you can play a more active role in your care and help others by contributing to medical research. A clinical trial will give you access to new experimental treatments before they are widely available. You will receive expert care from medical professionals at top healthcare facilities.
On the flip side, because the treatment you receive will be new and experimental, it may or may not be more effective than the standard of care—that is, the best available current treatment. This treatment may also have unknown side effects, which may or may not be worse than those of the standard of care.
A clinical trial may also place greater demands on your time. The clinical trial team may want to monitor you very closely, and ask you to visit more often or to stay at the healthcare facility. You may have to follow a more complicated treatment regimen or undergo extra tests.
Choosing to participate in a clinical trial is a big decision. Talking to your healthcare team, and equipping yourself with the pertinent information can help you make this decision and feel comfortable with it.
Phases of Clinical Trials
All clinical trials are assigned a phase. Only those drugs that meet the strict goals for safety and effectiveness may move on to the next phase. This process means that a drug that has just entered clinical trials can take up to five or more years to become commercially available for everyone.
Phase 1 (or I) trials determine safe doses of a drug or a combination of drugs, how often it should be taken, and its side effects. These trials may also test the effectiveness of a different formulation of an existing drug, or test the effects of an already approved drug on a different type of cancer.
Phase 2 (or II) trials assess how effective a drug is against a certain type of cancer using the safe dosage determined in the phase 1 trial. Researchers may also compare the effectiveness of different dosages to each other. They will, of course, continue to monitor the safety and side effects of the drug.
Phase 3 (or III) trials compare the new drug to the standard of care. The drug may be tested on its own or in combination with other drugs. These trials usually involve a large number of participants (hundreds to thousands) and are carried out at many different hospitals at the same time (a multi-site trial).
Phase 4 (or IV) trials are conducted once a drug has been approved by regulatory bodies such as Health Canada. Researchers gather more information about the drug’s effectiveness and side effects with longer-term use in a real-world clinical setting. Phase 4 trials also involve a large number of participants, sometimes including those who took part in phase 3 trials of the drug.
Treatment trials evaluate new treatments for cancer. These are the most common trials for people with cancer.
Prevention trials look at ways to prevent cancer in healthy people, in those who have a high risk for developing cancer, or in those who have a history of cancer. Participants in such trials do not have cancer at the time of the trial.
Screening trials evaluate ways to detect cancer in the early stages, even before they cause any signs or symptoms. Participants in such trials have a high risk for developing cancer.
Diagnostic trials look for better methods to diagnose cancer or determine its stage.
Supportive care trials or quality of life trials look at how to improve the life and comfort of people with cancer and cancer survivors; for example, with new techniques to reduce symptoms and side effects.
The informed consent form is a resource that can help you evaluate the risks and benefits of a clinical trial. Informed consent is part of the ethical standards followed by clinical trials. In addition to the risks and benefits, this document contains important details of the study, such as treatments, tests, side effects, duration, and who to contact if you have questions.
If you choose to participate in a clinical trial, you will have to sign the informed consent form. You will also have the right to withdraw consent and remove yourself from the clinical trial at any time.
Common words used to describe Clinical Trials
Protocol — A document written before a clinical trial begins that contains detailed information such as why a clinical trial is being done, its goals, who can participate (known as the eligibility criteria), how it will be conducted, and how it will determine the effectiveness of the experimental drug.
Endpoints — Measurable factors that allow researchers to determine whether the experimental drug is effective and whether the goals of the trial have been met. These are determined and defined before the clinical trial begins.
Randomized — Participants are randomly assigned to different groups. Those in the experimental group are given a new drug or a combination of drugs, whereas those in the control group are given the current standard of care treatment or a placebo. A placebo is an inactive substance that looks like the experimental treatment and is administered in the same way. Using a placebo prevents the patient and healthcare team from knowing which treatment is being given. This is another way in which trials avoid bias.
Open-label — Participants, and researchers, know which treatment they are receiving. No placebo is used.
Blind — Participants do not know whether they are receiving the experimental drug, another treatment, or a placebo. In a double-blind trial, neither the participants nor researchers know which group they have been assigned to. This is one way in which trials avoid bias.