Disease Modification & Stem Cells: Where Are We Now?

Researchers are finding new ways to measure how Parkinson’s disease (PD) progresses and how well promising treatments work. These discoveries could help make way for disease-modifying therapies; interventions that may slow, stop or possibly reverse brain changes in Parkinson’s. Learn more about research breakthroughs and where to exercise caution.

This article is based on an Expert Briefing hosted by movement disorders specialist and Parkinson’s Foundation National Medical Advisor, Michael S Okun, MD, director of the Norman Fixel Institute for Neurological Diseases, a Parkinson’s Foundation Center of Excellence.

Discoveries Driving Disease-Modifying Research: Biomarkers, Genetics and More

Parkinson’s is a progressive brain disease that scientists believe involves a mix of environmental and genetic factors. Researchers are beginning to uncover those complex connections and better understand the diversity of the disease as people with Parkinson’s have different genetic ties to PD, symptoms and rate of progression.

Parkinson’s can begin developing sometimes a decade or more before visible symptoms appear. This quiet evolution has historically made it difficult to test therapies early in the course of disease. Researchers were often unable to enroll people in testing for potential therapies until they had developed the movement symptoms used to diagnose Parkinson’s or learned they had a genetic link. 

Research advances are helping scientists uncover who may be at risk, measure disease biology and test therapies in more targeted ways, including:

Biomarkers: The discovery of biomarkers in PD, substances in the body that provide clues about health, is changing the field. Diagnosis still relies on neurological exams, symptom history and response to dopamine therapies, but key PD biomarker tests can support a diagnosis. Researchers are working toward defining Parkinson’s by biology rather than symptoms. Biomarkers could help diagnose PD earlier, track disease progression and show whether treatments are working.

Focusing on alpha-synuclein: Clumps of misfolded alpha-synuclein proteins are linked to brain changes in Parkinson’s. Researchers are exploring ways to reduce alpha-synuclein production, prevent it from misfolding and clumping or to stop its spread.

Genetic studies: Groundbreaking research, such as PD GENEration: Powered by the Parkinson’s Foundation, is having a tremendous impact in detecting genetic variants linked to Parkinson’s. This work is helping people access clinical trials earlier and driving the development of personalized treatments. 

Thanks to the more than 35,000 people who have already joined PD GENEration, the Parkinson’s Foundation has learned that around 13% of people have a Parkinson’s related genetic variant, a big increase from earlier research estimates of 5 to 10%. The ever-growing study is continuing to propel new discoveries.

Active clinical trials that test new therapies are targeting genetic variants identified through PD GENEration testing, such as LRRK2. Clinical studies for therapies targeting a mutated GBA gene, one of the most common genetic risk factors for Parkinson’s, are also underway. 

Stem cell therapies: Research are exploring the potential of using tissue cells that can be transformed into dopamine neurons to address dopamine loss in Parkinson’s. Stem cell studies suggest that this approach may one day help improve PD symptoms. 

Some promising stem cell studies are moving closer to Phase 3 clinical trials, often one of the last steps before a drug manufacturer seeks approval from the U.S. Food and Drug Administration.

Other research areas to watch include:

• Glucagon-like peptide-1 (GLP-1) receptor agonists. These and similar therapies, initially targeted at weight loss and type 2 diabetes, are being explored for the potential to improve Parkinson’s symptoms.
• Studies exploring the gut-brain connection in PD. Scientists have discovered that Lewy bodies (clumps of misfolded alpha-synuclein proteins linked to brain disruption in Parkinson’s) can also be found in the gastrointestinal tract of people living with PD. Dietary interventions to alter gut bacteria and change the course of Parkinson’s may be on the horizon.
• Focused ultrasound is an advanced PD treatment that may lessen motor fluctuations when medications are no longer effective. Low-intensity focused ultrasound, an emerging technique, is being explored to temporarily open the blood-brain barrier to deliver targeted PD trial treatments directly to the brain.
• Scientists are exploring whether a gene-editing tool called CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) could address PD-related genetic targets.

Exercising Caution

Though hopeful progress is happening in disease-modifying therapies and stem cell research for Parkinson’s, legitimate trials are critical. Dubious and sometimes dangerous offerings have been shut down by the FDA and regulatory agencies all over the world. 

Stem cell tourism, travel to places with little medical or scientific regulation for unverified treatments, can put people at serious health and financial risk.

⚠️Be careful with any trials or experimental treatments that make big promises, skip over risks or ask for payment. Clinical trials do not charge people to take part.  

If you are considering a trial, be sure to ask questions about study protocols and talk with your healthcare team to determine whether it feels like the right fit. These websites can help you learn more about clinical trials for Parkinson’s:

• Join A Study — a Parkinson’s Foundation webpage that lists ongoing PD research studies.
• ClinicalTrials.Gov — a public database with active and completed clinical studies in the U.S. and around the world.

Learn More

Building the foundation for a cure is at the heart of the Parkinson's Foundation mission:

• Learn more about clinical trials and Parkinson’s.
• Discover how our research is changing the course of Parkinson’s.
• Get involved: Join opportunities like the PD GENEration genetic study to advance understanding of Parkinson's and accelerate new therapies. 
• Learn how PD Trial Navigator is connecting PD GENEration participants with clinical trials relevant to them.