Less than 1 percent of people with Parkinson’s participate in drug research studies. People with Parkinson’s participate in research for various reasons. Some do so with the hope of finding a new treatment for themselves. Some want to contribute to knowledge that will benefit others in the future.
When deciding if a research trial is for you, it’s important to understand that, although everything is done to insure the safety of research subjects, the true safety and benefit of experimental treatments are not yet known.
Prescription drugs would not be available without volunteer research subjects. Every prescription drug used to treat Parkinson’s disease has been tested in clinical trials prior to approval by the Food and Drug Administration (FDA).
There are many research hurdles a potential drug must clear before being approved for use. It must first undergo rigorous testing for safety and benefit in pre-clinical studies, those that involve animals or take place in laboratory settings.
Only drugs that pass this rigorous safety test are made available for clinical trials, which are studies involving humans.
Listed here are the new Parkinson’s drugs made available through clinic trials over the past five years.
Azilect (Rasagiline)—This MAOB inhibitor approved for early Parkinson’s may have disease-modifying properties.
Neupro (Rotigotine) patch— Patches allow for smooth, long-lasting effects, but these patches were recalled due to crystallization.
Parcopa—Orally disintegrating carbidopa/levodopa tablets
Requip XL—Once-a-day, long acting dopamine agonist
Zelapar—Dissolving tabs; a reformulation of selegiline
Exelon patch—For Parkinson’s disease memory problems
What are the types of drug trials performed?
There are four phases of clinical trials. These phases progress from the earliest stage of discovery, testing drugs on just a few people to extensive testing after a drug is approved and prescribed to many.
- Phase I. Tests the drug in a small number of individuals (20 to 80) to evaluate its safety, identify side effects, and determine the best dose for study.
- Phase II. Extends this work to include a larger number of people (100 to 300).
- Phase III. Patients most commonly participate in Phase III and IV clinical trials. In these trials, the medications have already been tested for safety in a small number of volunteers. Their benefits and side effects have been documented and compared to exiting treatments. The drug shows promise so extensive study in many people (1000s) is needed before the drug can be approved by the FDA for a specific problem.
- Phase IV. Ongoing drug testing or surveillance in the general population after a medicine is approved and available for prescription use. These studies search for problems and benefits in the general population representing more diversity of people and often search for other problems that the drug may help.
The FDA serves as the governing body that approves a treatment if efficacy and safety outcomes are reached in Phase III trials.
Benefits of Placebo Controlled Trials
Many research trials include a placebo control. In such trials there is the chance you will not be given the active medicine but will instead receive an inactive pill or treatment.
In “double blind” studies, neither the researcher nor the volunteer knows whether or not the active pill or treatment has been administered.
A strong “placebo effect” is well-documented in Parkinson’s studies. Simply expecting that a medicine will help can increase the chance of experiencing an improvement to symptoms.
Placebo-controlled trials, then, help insure that any benefits experienced are the result of the medication or treatment being tested, rather than the influence of positive expectations.
Many placebo-controlled clinical trials are followed by an extension trial that allows all patients to receive the active drug.
There are plenty of good reasons to participate in clinical research, beyond the obvious benefits to science. Knowing you’re making a difference can feel empowering to patients, suggests neurologist Pinky Agarwal, M.D., of the Booth Gardner Parkinson’s Care Center.
“By participating in a clinical trial, patients are able to play a more active role in their health care,” Agarwal says.
Research trials are not for everyone. It is important to know your rights as a research participant before you participate in any research.