Thanks to researchers from the University of Georgia’s Regenerative Bioscience Center and startup ArunA Biomedical, stroke victims have a renewed sense of optimism when it comes to one day fully recovering. The new treatment, called AB126, uses stem cells to decrease brain damage and increase the brain’s natural healing tendencies. As of late-February, clinical trials have proven effective on both mice and pigs. Scientists are now looking to begin tests on humans in 2019.
The treatment will mean a second chance for hundreds of thousands of people. According to the Stroke Association, one person suffers from a stroke every two seconds and strokes are the fourth leading cause of death in the UK. Before we understand the future of treatment, we must first look to understand why strokes occur.
Ischaemic strokes – which account for 85 percent of all strokes – are caused by a blockage that cuts off blood supply to the brain. Haemorrhagic strokes – which account for the other 15 percent of all strokes – are caused by blood vessels bursting within or on the surface of the brain. In either case, because the brain is affected, the whole body bears the burden. Mobility in both arms and legs is decreased, patients will likely suffer from pain and headaches, and they will also have trouble speaking, understanding, reading, writing, and controlling their bowels.
The consequences of strokes are devastating and far-reaching, impacting nearly every aspect of day-to-day life for survivors. Currently, the best treatment for these victims is tPA (tissue plasminogen activator). This FDA approved IV works by dissolving the blood clot and improving blood flow. While – yes – it has been proven to reverse side effects, it’s only effective if administered within three hours of the stroke. Doctors estimate that only 5 percent of patients are able to make that very limited window.
Unless patients are able to seek treatment within three hours of their stroke, their options are limited to rehabilitation. Recovery depends on the severity of the stroke’s complications.
With AB216, the window is still slightly limited. Researchers are currently administering the treatment no more than 6 days after the patient suffered from the stroke. Of course, this is quite a substantial increase in time from three hours as is the case with tPA.
The study, which was published in the journal Translational Stroke Research, details how extracellular vesicle fluid filled structures called exosomes are used to decrease the amount of brain tissue lost in the injury. These exosomes – which are present in eukaryotic fluids (blood, urine, etc.) – are especially useful in that they can carry multiple doses of treatment and are small enough that they’re able to cross barriers that other cells can’t.
When tested on mice, MRI scans showed close to 35% decrease in size of injury and a 50% decrease reduction in brain tissue loss. This is the first time such results have been seen in exosome stroke treatment studies.
ArunA is already producing AB126 exosomes to meet post-trial demands, with an eye to maintain consistency while still keeping the cost of production low. As apart of their trials, researchers intend to test the effects of the new treatment on traumatic brain and spinal cord injuries as well as epilepsy.
This exciting development is the third in a series that started in 2014 in London. There, researchers from Imperial College Healthcare NHS Trust and Imperial College London, used stem cells from bone marrow in the rapid treatment of strokes. It was the first of its kind published in the UK and the results were encouraging. A particular set of CD34+ stem cells – known to help with the production of blood cells and blood vessels – was used. Four out of five patients were able to live independently six months after suffering a severe stroke that historically leaves only four percent of victims alive.
In 2016, scientists at Stanford University used mesenchymal stem cells, which can mature into multiple types of specialized cells, to restore brain function. The trial involved 18 stroke victims and after depositing the stems cells directly into their brains, one woman made a near full recovery as she regained the function in her legs and learned how to walk again.
Given the progress that has been made over the last several years, stroke victims have a lot to look forward to in 2019 when human trials begin for AB126.