Charting a new course for Parkinson’s Disease
Imagine replying to an urgent text while riding in the passenger seat of a car travelling on a cobbled street. Imagine getting to bed at the end of a long day, and not being able to sleep for more than a few minutes straight. Imagine walking uphill while carrying a heavy backpack. Imagine a life where every day is a fight to regain control of your movements; where the messages your brain is sending your body get disrupted somewhere along the line.
Unfortunately, this is the hard-hitting reality for 10 million people suffering from Parkinson’s Disease — the most common neurodegenerative movement disorder in the world.
What is Parkinson’s Disease?
In 1817, the English doctor James Parkinson published a medical essay detailing a chronic, slowly progressive disease of the nervous system characterized by a combination of tremors, rigidity, and stooped posture — the first description of Parkinson’s Disease.i Later on, scientists determined that Parkinson’s was caused by a marked reduction of cells that produce the neurotransmitter dopamine — a chemical messenger responsible for regulating body movements, among other functions. Parkinson’s Disease often starts with an uncontrollable tremor in one hand and a feeling of stiffness in the body. Over time, other symptoms may develop like slurred speech, shuffling gait, loss of sense of smell, dementia, and depression.ii
Men are 50 percent more likely to develop Parkinson’s than womeniii, and in most people, symptoms appear at the age of 60 or over.iv With time, symptoms worsen, making simple tasks like climbing stairs, writing a letter or eating and drinking very challenging and heavily impacting the quality of life.iv
What are current Parkinson’s Diseases treatments?
Even two centuries after Parkinson identified the disease, we have no cure for Parkinson’s Disease. The standard therapy aims to provide symptomatic relief. Dr. Emile Nuwaysir, CEO and President of BlueRock Therapeutics* says, “The standard of care for Parkinson’s Disease, the drug that we use to treat our loved ones, was discovered 66 years ago. Since then, we have not seen any fundamental changes in the therapy. That is an astounding fact when you think about it, in comparison to the advancements we’ve had in other fields. For example, in aviation, we went from the Wright brothers’ first flight to Neil Armstrong walking on the moon, in 66 years.”
In the late 60s and 70s, clinical researchers discovered that they could treat Parkinson’s Disease with dopamine replacement therapy. While replacing the lost dopamine eased symptoms and slowed the progression of Parkinson’s, it didn’t address the root cause of the disease — an irreversible loss of neurons. The question researchers then began to ask was “How do we prevent neurons from degenerating?” It would take another two decades to find the answer.
What if we could reverse lost cell function?
Cell and gene therapies offer a massive paradigm shift from current treatment options and hold the potential to revolutionize the way we treat diseases. These therapies focus on the source of the disease rather than the external manifestation of it. With these approaches we could potentially stop or even reverse the pathology of diseases like Parkinson’s Disease.
How can cell therapy help with future treatments in Parkinson’s Disease?
In cell therapy, healthy intact cells are cultured and transferred to the body to replace damaged cells associated with diseases. The human body is made up of around 200 different types of cells, each cell is specialized to carry out a particular role. Stem cells are rudimentary cells that haven’t undergone differentiation and can be induced to grow into any type of cell. The pioneering work of Noble prize winners, John Gurdon and Shinya Yamanaka marked a defining moment in this field enabling scientists to convert adult skin cells into what are called induced pluripotent stem cells (iPSCs). These cells can be differentiated using specific growth factors into most types of cells — heart muscle, liver, or nerve cells.
BlueRock Therapeutics has studied the use of stem cell-derived neuron cells to replace damaged neurons in neurodegenerative diseases like Parkinson’s Disease and is now advancing a Phase 1 study in patients with advanced Parkinson’s Disease. The therapy is intended to restore motor function by replacing dopamine carrying neurons that are damaged by Parkinson’s. The trial could potentially demonstrate that Parkinson’s Disease is, in principal, reversible and this in turn could represent an enormous step for people with Parkinson’s worldwide.
What can gene therapy do in future treatments with Parkinson’s Disease?
Each cell carries its own genetic code in the form of DNA that translates into different functions. Gene therapy focuses on the use of DNA as a drug to correct inherited genetic abnormalities or to restore functions lost due to disease. One approach is for a functional gene to be inserted in carefully engineered viruses and administered to the patient. At AskBio**, researchers are investigating the role of glial cell line-derived neurotrophic factor (GDNF) gene therapy for the treatment of Parkinson’s Disease. GDNF is a growth factor that promotes healthy functioning of brain cells by enhancing levels of this naturally occurring growth factor. GDNF gene therapy is intended to promote the survival and function of vulnerable brain cells that degenerate in Parkinson’s Disease. Katherine High, MD & President at AskBio says, “It is our duty as researchers to constantly challenge the status quo and explore new and unconventional ways of treating diseases. We are in the midst of early clinical studies with a therapy that works on the brain’s own cellular machinery to regenerate cells. The research looks very encouraging, and we are excited to see what this could do for the Parkinson’s Disease community.”
For people with Parkinson’s Disease, cell and gene therapies could mean a new reality – a reality where treatment options go beyond symptoms and where Parkinson’s Disease could become a disease that might be stopped or even reversed.
Footnotes
*BlueRock is a preclinical stage biopharmaceutical company and wholly owned subsidiary of Bayer AG
** AskBio a clinical-stage adeno-associated virus (AAV) gene therapy company and wholly owned subsidiary of Bayer AG
i Claire M. Gavin G, Annette H, Richard W, et al 200 Years of Parkinson’s disease: what have we learnt from James Parkinson?, Age and Ageing, Volume 47, Issue 2, March 2018, Pages 209–214, https://doi.org/10.1093/ageing/afx196
ii Parkinson’s Disease and its causes. Available from https://www.medicalnewstoday.com/articles/323396. [Accessed March 2021]
iii Moisan F, Kab S, Mohamed F, et al Parkinson disease male-to-female ratios increase with age: French nationwide study and meta-analysis Journal of Neurology, Neurosurgery & Psychiatry 2016;87:952-95
iv Parkinson’s Disease: Challenges, Progress, and Promise. National Institute of Neurological Disorders and Stroke. Available from https://www.ninds.nih.gov/Disorders/All-Disorders/Parkinsons-Disease-Challenges-Progress-and-Promise. [Accessed March 2021]
