A $23 million grant from the National Institutes of Health will support a new Phase 3 clinical trial to evaluate the drug isradipine as a potential new treatment for Parkinson’s disease. The study is being co-lead by the University of Rochester and Northwestern University.
“Isradipine has been demonstrated to be safe and tolerable in patients with Parkinson’s disease,” said University of Rochester School of Medicine and Dentistry neurologist Kevin Biglan, M.D., co-principal investigator of the study. “This new study will determine whether the drug can be an effective tool in slowing the progression of the disease and could, thereby, complement existing symptomatic treatments and improve the quality of life of individuals with the disease.”
“If it proves to be effective, this drug will change the way we treat Parkinson’s disease, and the major advantage of it is that isradipine is already widely available, inexpensive and will allow for rapid translation of our research into clinical practice,” said Tanya Simuni, M.D., principal investigator of the study, professor of neurology at Northwestern University Feinberg School of Medicine. “Although we now have very effective symptomatic treatments to manage Parkinson’s, the development of a disease-modifying intervention remains a critical goal.”
Isradipine is a Food and Drug Administration-approved drug to treat high blood pressure. Researchers suspect that the drug may also be effective in treating Parkinson’s for a couple reasons. First, population scale studies have shown that people taking the drug for high blood pressure have a lower incidence of Parkinson’s disease. Additionally, isradipine is in a category of drugs called calcium channel blockers, meaning they inhibit certain cellular functions. Researchers speculate that overactive calcium channels may play a role in the death of the dopamine producing cells in the brain that is one of the hallmarks of Parkinson’s.
Parkinson's disease is a progressive neurological disorder that erodes an individual’s control over their movements and speech. Over time, Parkinson’s patients experience stiffness or rigidity of the arms and legs, slowness or lack of movement, and walking difficulties, in addition to tremors in their hands, arms, legs, jaw or face.
A Phase 2 evaluation of isradipine, which was conducted to determine the safety and appropriate dosage for the drug, was completed in 2012. The study was funded by a $2.1 million grant from The Michael J. Fox Foundation for Parkinson’s Research (MJFF), which also supported preclinical research into the effects of isradipine on Parkinson’s progression by Northwestern University.
“Our de-risking model quickly advances promising research ideas toward larger investment and, thereby, closer to clinical application,” said MJFF CEO Todd Sherer, Ph.D. “The NIH funding to continue testing of isradipine brings us one step closer to a disease-modifying therapy that could make a real difference in the lives of millions.”
The new clinical trial – titled STEADY-PD3– will recruit 336 individuals with Parkinson’s disease at 56 sites throughout North America, including the University of Rochester. The study – which is scheduled to begin recruiting Parkinson’s patients later this year – will follow the participants for three years. The primary goal of the study is to determine whether the drug can slow the progression of the disease.
Physicians currently have several tools at their disposal that enable them to effectively manage the symptoms of the disease for a period of time, however, no treatment exists that can slow the progressive deterioration of function. Consequently, many patients diagnosed with Parkinson’s will experience a “honeymoon” period of two to five years during which existing treatments can essentially help them to lead a normal life. But over time, these treatments become less effective.
One of the goals of Parkinson’s research is to identify new therapies – such as isradipine – that could slow the advance of the disease by keeping the brain’s dopamine-producing cells healthier for a longer period of time. Researchers believe that the development of disease modifying approaches – commonly referred to as neuroprotection – and new ways to monitor the progress of the disease when complemented with existing symptom-managing therapies could help hold disability at bay.
“We have good early stage treatments for the symptoms of Parkinson’s disease and individuals who have problems with mobility and coordination can often get back to where they can function at a very high level,” said Biglan. “However, over the long term problems arise due to disease progression and people become less responsive to therapy. If you could slow the progression sufficiently enough, then with existing symptomatic treatments you could manage Parkinson’s symptoms quite well over a much longer period of time.”
STEADY-PD3 – which is being funded by the National Institute of Neurological Disorders and Stroke – will involve researchers from the Parkinson Study Group , which was founded in 1986 and consists of more than 400 active investigators, coordinators, and scientists located at 126 institutions throughout the United States and Canada. The University of Rochester’s Center for Human Experimental Therapies will provide project management and data coordination for the study and David Oakes, Ph.D., with the Department of Biostatistics will serve as lead biostatistician. Carematix will support clinical trial operations including data management and real time uploading of blood pressure readings from patients at home. Verizon Enterprise Solutions will provide the communications technology that enables the exchange of data so that patient information can be securely transmitted to researchers for analysis and interpretation.