Cancer and heart disease may rightly garner a lot of the world's attention, and they typically account for a big chunk of the pharmaceutical sectors' research and development budget, but the sheer number of Parkinson's disease cases in the United States and worldwide is pushing this disease up the metaphorical ladder and making it just as much of a priority for researchers.
This is a growing problem
Parkinson's disease is a progressive disorder that affects the nervous system and results in the eventual degradation of a person's motor function. The root cause of the problem is that nerve cells in the brain stop producing adequate levels of dopamine, and there currently is no cure. In the early stages of the disease, minor symptoms may appear, including trembling of the extremities or the face, poor balance and coordination, or stiffness in a person's arms or legs. In more advanced stages, Parkinson's can affect a person's ability to walk, talk, sleep, chew food, or even swallow.
According to the Parkinson's Disease Foundation (PDF), as many as 1 million Americans may be living with Parkinson's disease right now, with approximately 60,000 new cases being diagnosed each year. Worldwide, the PDF estimates some 7 million to 10 million cases have been diagnosed.
But Parkinson's disease isn't just a killer -- it's also a financial burden on patients, their families, and the healthcare system. The PDF estimates that the direct costs (such as medical costs and hospitalization) and indirect costs (e.g., lost wages and premature death) of Parkinson's disease total almost $25 billion per year! Medication costs the average Parkinson's disease patient more than $200 per month, while therapeutic surgery can run upwards of $100,000.
Long story short, a variety of therapeutic options are needed to combat Parkinson's disease -- and researchers at Harvard Medical School's McLean Hospital and Singapore's Nanyang Technological University may have the discovered the answer.
Could a groundbreaking Parkinson's treatment soon be on the way?
While a majority of previous Parkinson's disease studies have resulted in failure, new data unveiled this past week in Proceedings of the National Academy of Sciences of the United States of America, an online journal, suggest a cure for Parkinson's disease may be possible.
Researchers from both universities screened more than 1,000 drugs approved by the Food and Drug Administration and discovered that two FDA-approved drugs -- chloroquine and amodiaquine -- could bind and activate a type of protein known as Nurr1 to fight Parkinson's disease. Nurr1 is the protein that protects the brain's nerve cells and allows them to produce dopamine. If dopamine production were to continue without degradation, a patient shouldn't experience progressive motor function loss.
As professor Kwang-Soo Kim, one of the participating researchers and a noted Parkinson's disease expert noted:
Nurr1 is known to be a potential drug target to treat Parkinson's. Despite great efforts from pharmaceutical companies and academia, no one has managed to find a molecule which can directly bind to it and activate it, except for us.
The researchers tested their model on rats in a laboratory and discovered that rats in which Nurr1 was activated exhibited improved behavior and didn't appear to be suffering from Parkinson's disease. Researchers still plan to look into additional drug combination that can halt or slow the progression of Parkinson's disease and noted their intent to modify the existing formulations of chloroquine and amodiaquine for human clinical trials (which they hope to begin soon).
Other pathways exist, but the failure rate is high
The only downside to the newly released study is that it's not even in human clinical trials yet. This implies that any developed drugs targeting Nurr1 could be a half decade or longer away from making their way to pharmacy shelves.
In the more immediate future other pathways to treat Parkinson's do potentially exist, but the many failures that have preceded the Harvard-Singapore study suggest people shouldn't get their hopes set too high.
One experimental therapy worth keeping your eyes on is CVT-301, an inhaled formulation of levodopa. In December, Acorda Therapeutics (NASDAQ:ACOR) began enrolling in a phase 3 study involving CVT-301 for Parkinson's disease patients experiencing OFF episodes (an OFF episode is where a patient experiences a relapse of their symptoms despite taking their Parkinson's medication). The goal of CVT-301 is to deliver levodopa through the lungs and return the patient to an ON position where their symptoms are kept at bay by medication. Acorda notes that around half of all people taking levodopa (the current standard of care treatment for Parkinson's) experience OFF episodes.
In mid-June Acorda presented encouraging data from its phase 2b study involving CVT-301 at the International Congress of Parkinson's Disease and Movement Disorders' annual event. As the data showed, CVT-301 demonstrated a "statistically significant and clinically important reduction in average UPDRS III [Unified Parkinson's Disease Rating Scale Part 3] motor score compared to the placebo (p<0.01) and across all measured time points beginning at 10 and up to 60 minutes post-administration."
If all goes well, Acorda could file for a new drug application as soon as late 2016 and have its product on pharmacy shelves, assuming a priority review, by or before mid-2017.
But we've been excited about Parkinson's disease drugs before only to see them end in failure.
In May 2013, Big Pharma Merck halted future studies involving preladenant as a treatment for Parkinson's disease after its failed to statistically outpace the placebo in three separate phase 3 studies (two combined with levodopa and one as a monotherapy).
The failure bug also struck Acadia Pharmaceuticals in 2009 causing its stock to lose two-thirds of its value in a single day after pimavanserin missed its primary endpoint of reducing the number of hallucinations and delusions associated with Parkinsons's disease compared to the placebo.
Failure has become an all-too-common occurrence when studying treatments for Parkinson's disease, and my hope is that CVT-301, or perhaps the work being conducted at Harvard Medical School's McLean Hospital and Nanyang Technological University, will someday change that.