Oct 11, 2016

Everything You Need To Know About Clinical Trials


What is a clinical trial?
Clinical trials are experiments that test whether a new intervention, such as a drug or surgery, will work in people. The main goal of clinical trials is to determine if the new intervention is safe and effective.

Why use the word intervention instead of treatment?
When talking about clinical trials, it’s important to use the word “intervention” instead of the word “treatment” because it helps everyone to remember that the drug and/or surgery that the participant is receiving is not an established treatment. In other words, we do not know if the intervention is safe or effective. Even though a clinical trial is an experiment, many participants are very hopeful that it might benefit them. Actually, many clinical trial participants might be unaware, for example, that there is a possibility of only receiving a placebo (a fake intervention), rather than the new intervention. Clinical trial participants need to understand that they are research participants and that investigators are evaluating if the intervention is helpful, harmful, or no different than other available alternatives.

What are the different phases of clinical trials?

Phase 0
Exploratory study with NO therapeutic goals

Phase 1
A study to evaluate SAFETY. Sometimes these trials are conducted in healthy volunteers. For rare diseases and highly risky interventions, such as gene and stem cell therapies, these trials are conducted in patients with the condition being studied.

Phase 2
A study that gathers PRELIMINARY data on effectiveness in the patient population.

Phase 3
Usually a larger study to assess safety and effectiveness in different patient populations. It usually compares the new intervention to current treatments or a placebo. A placebo is a fake intervention. Participants and the doctors running the trial may not know if participants are receiving the new intervention or the alternative (control). This is known as a randomized controlled trial (RCT).

Phase 4 
Monitoring of safety and efficacy after the intervention has been approved for use in patients by a regulator, such as Health Canada.


Where can I learn about clinical trials for my eye disease?
If you would like to learn about the many different clinical trials that are happening around the world, you can find lots of information at This site is known as a clinical trials registry.

It is very important to note that registries do not check the quality of the clinical trial. Registered clinical trials may not have ethics approval from the center that is running the trial. Registered clinical trials may not have approval from a national regulatory agency such as Health Canada or the United States Food and Drug Administration (FDA). This means that some of the trials on this site might pose significant risks. Therefore, it is essential that you discuss your interest in a particular trial with your medical doctor.

If you would like to learn more about clinical trials that are available in Canada and approved by Health Canada (such as Dr. Ian MacDonald’s clinical trial for choroideremia) you should search this website:

After investing in sight-saving research for more than 40 years, everyone at the FFB is incredibly excited to see that discoveries are making their way into the clinic where they will impact people living with blinding eye diseases! But, we also want to caution the entire FFB community to be careful. Please do not trust people who are promising unproven miracle treatments that will cost you lots of money. If there is a new treatment that works – we will tell you about it! If you find information about a clinical trial or a possible new treatment on a different website, please tell us about it and we will check into it for you.

By Dr. Mary Sunderland, Director of Research and Education at the Foundation Fighting Blindness, with contributions from Dr. Tania Bubela, Professor, School of Public Health, University of Alberta.





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