Why Should I Participate in a Clinical Trial?
Reviewed by: HU Medical Review Board | Last reviewed: March 2017 | Last updated: March 2021
Clinical trials are a type of research in which new treatments are tested on human patients. Clinical trials are an important part of the scientific process to find and prove the effectiveness and safety of new medications and treatments.
For diseases like Parkinson’s disease (PD), where the exact cause is still unknown and there are no current treatments that can cure or slow the progression of the disease, clinical trials are essential to finding the answers.1,2
What are the types?
Clinical trials can be generally classified as observational or interventional. Observational clinical trials observe the participants and monitor their health over a period of time. No new drugs or treatments are given to participants in an observational trial.
Observational trials help researchers understand how a disease progresses and gives information that can help them decide how to treat it. Interventional clinical trials test a new drug, therapy or experimental treatment. Interventional trials are designed to assess the new treatment’s safety and effectiveness. Additional subcategories of clinical trials include:
- Treatment trials, which test treatments that may relieve symptoms of PD or slow the disease progression
- Prevention trials, which look at medicines, nutritional supplements, or lifestyle changes that may prevent or lower the risk of developing PD
- Screening trials, which investigate ways to diagnose PD, especially in the early stages of the disease
- Quality of Life trials, which study ways to increase quality of life for people living with PD
- Genetics trials, which look at the inherited risk of PD1
What happens in each phase?
There are four different stages of clinical trials that medications go through:
- Phase I: the researchers test a new drug on a small group of people (10-80) to evaluate its safety, determine a safe dose, and evaluate any potential side effects
- Phase II: a larger group of people (100-300) are given the drug to determine its effectiveness and further evaluate safety
- Phase III: the drug is given to large groups of people (1,000-3,000) to confirm its effectiveness, evaluate side effects, compare it to existing treatments, and identify any additional information about how to use the drug safely
- Phase IV: additional studies done after the drug is approved by the Food and Drug Administration (FDA) and is available in the market to gather information on long-term use1,2
The clinical trial process is long and expensive – it takes many years for a product to go through all the necessary phases, and the majority of potential treatments fail to show effectiveness to move to the next phase. In addition, many trials fail because they do not have enough participants.
Regulatory agencies like the FDA require large groups of participants in trials to ensure the safety and effectiveness of therapies before they are brought to market. It is estimated that 80-85% of clinical trials are delayed due to challenges finding and enrolling participants, and about 30% of trials fail because they can’t recruit any participants.1
In addition, for neurodegenerative diseases, it is becoming more apparent that identifying and treating people in the early stages of the diseases improves the likelihood that a treatment will be effective. Correctly diagnosing PD is also important.
Some motor symptoms may be similar to PD, but may be caused by another type of disease, and the treatments may be effective for people with PD alone. The development of biomarkers (molecules in the blood, cerebrospinal fluid, or urine) and research into imaging of the brain can potentially help correctly diagnose individuals with PD.
How to find a trial
The Michael J. Fox Foundation for Parkinson’s Research has created the Fox Trial Finder, a matching tool that helps connect people with the trials that are appropriate for them, whether they have PD or not. By creating a profile on the website, volunteers are notified about trials in their region that are recruiting.1
The U.S. National Institutes of Health also has a database of clinical trials at their website, ClinicalTrials.gov. The NIH site lists trials that are being conducted around the world.3