What is the Report Card on Symptomatic, Cure-Based and Disease Modifying Strategies for Parkinson’s Disease?
The hope of every person with Parkinson’s disease is that we will introduce meaningful disease modifying therapies. There is however often confusion as to what this means. The approaches for treatment of Parkinson’s disease can be broadly classified into three categories:
- Cure based strategies
- Disease modifying (also referred to by some studies as neuroprotective)
So, what is the current report card on Parkinson’s disease therapies? Below is my opinion:
- Meaningful symptomatic therapies get a grade: B+/A- There are many drugs, devices, and behavioral treatments that have been shown effective and/or promising. There is however much work to be done and particularly on non-motor symptoms and levodopa resistant symptoms that emerge with disease progression.
- Cure gets a grade: F To date, there has been little progress on an absolute cure and one overall cure is unlikely given the many potential causes of Parkinson’s disease. Additionally, Parkinson’s is not one disease (only about 10% are single gene defects) so there likely won’t be one cure. If we one day see a cure, it will likely be for a subset of patients.
- Disease modifying drugs get a grade: C The Holy Grail among the current generation of Parkinson’s disease researchers has been the development and testing of drugs that can arrest or meaningfully slow Parkinson’s disease progression. A universal theme among all Parkinson’s disease patients is the yearning for a therapy that would pause this progressive degenerative disease. The field is trying desperately to identify a disease modifying therapy, but there are barriers in the understanding of basic science and the ability to translate findings into the clinic.
Examples of drug therapies that have been tried for disease modification or neuroprotection and have not been shown effective are:
- GLP-1 agonists
- CoganeTM – PYM50028
- Sapogenin PYM50028 (steroidal)
- Exendin-4 and liraglutide – GLP agonist
- CX-516 ampakine
Drugs like Inosine, Isradipine and Exenatide are already FDA-approved for other diseases and are possible therapies for disease modification, but keep in mind that they could also impact symptomatic treatment of Parkinson’s disease. It is also possible that antimalarial drugs may be repurposed for both disease modification and treatment of Parkinson’s disease. Additionally, a leukemia drug was recently repurposed (Nilotinab), and we will likely see dozens more efforts at repurposing. Finally, approaches like vaccines and monoclonal antibodies may have symptomatic and disease modifying effects. The good news for patients is that many trials are underway.
One issue with moving forward and improving disease modification is our lack of a biomarker to track progression. Blood tests and imaging studies are being developed to diagnose Parkinson’s disease, however there are many limitations in their use for clinical trials and in tracking disease progression.
The bottom line is although the report card on cure-based and disease modifying strategies for Parkinson’s Disease is not where we would like to see it, we are moving in the right direction.
Michael Okun, MD presented at the Third World Parkinson Congress in Montreal, Canada and the Fourth World Parkinson Congress in Portland, OR, USA. He also serves on the Comprehensive Care Committee for the Fifth World Parkinson Congress. He is currently Chairman of Neurology, Professor and Co-director of the Center for Movement Disorders and Neurorestoration at the University of Florida College of Medicine.
Ideas and opinions expressed in this post reflect that of the author(s) solely. They do not necessarily reflect the opinions of the World Parkinson Coalition®