There may be some things more terrifying than a stroke — but not many.

Ischemic stroke is a heartbreaking, life-changing event that affected an estimated 700,000 people last year in the U.S. alone and is the leading cause of disability.

The only FDA-approved drug to treat the most common type of stroke — Genentech ’s (South San Francisco, California) tissue plasminogen activator (tPA) — must be given within three hours, so the clock is ticking from the moment symptoms begin.

Although tPA has been shown to save lives and prevent brain damage, Rick Schallhorn, VP of Marketing and R&D for CoAxia (Maple Grove, Minnesota), told Medical Device Daily that only about 3%-4% of ischemic stroke patients show up to the emergency room in time to receive the clot-busting drug.

CoAxia is trying to widen the window for ischemic stroke patients with its NeuroFlo Perfusion Augmentation Therapy. The company last week reported the enrollment of the first two patients in its Flo 24 safety and feasibility study of NeuroFlo in ischemic stroke patients who show up for treatment as late as 24 hours after stroke onset. CoAxia said it believes NeuroFlo is the first intervention evaluated which attempts to improve blood flow to the brain this late after a stroke.

Schallhorn said the Flo 24 trial will enroll 25 patients and that the first two patients in the trial “seem to have done well” and “seem to have benefited” from the treatment.

The company said Flo 24 complements its ongoing SENTIS pivotal study, which is evaluating the NeuroFlo treatment in patients up to 10 hours after the onset of their symptoms. The SENTIS trial has now enrolled more than 65 patients at more than 20 major medical centers, the company noted.

“We are pleased to extend the evaluation of NeuroFlo treatment in patients up to 24 hours. These are patients who usually do not qualify for treatments aimed at reopening blocked arteries in the brain, because these treatments tend to be risky after the first few hours,” said Maxim Hammer, MD, director of clinical research at the University of Pittsburgh Stroke Institute (Pittsburgh), who enrolled the first patient in the trial.

“It is exciting to be part of a clinical trial with NeuroFlo, an alternative approach to treating stroke. In most hospitals our patient would have had no option for treatment. The NeuroFlo treatment was delivered with no adverse events and with clinically noticeable improvement.”

The NeuroFlo treatment is intended to deliver blood to the affected area of the brain by providing an increase in blood flow via alternative, collateral pathways around the blocked artery.

The device, a dual-balloon catheter, is placed in the descending aorta and works by restricting flow in the descending aorta and thus increasing blood flow to the brain, according to CoAxia.

Schallhorn said the NeuroFlo treatment could potentially benefit hundreds of thousands of stroke patients.

“Our case tells a story of a new era in stroke, where advanced imaging with CT or MRI can select optimal candidates for aggressive interventions, many hours beyond traditional time windows, to reverse the devastating consequences of stroke,” said David Liebeskind, MD, associate neurology director of the UCLA Stroke Center (Los Angeles) who with his colleagues enrolled the second patient. “On a daily basis, people awaken with stroke symptoms or arrive at an emergency room far beyond the time limitations of approved stroke treatments. Imaging of collateral blood flow downstream from a blocked artery, and enhancing that flow with the NeuroFlo treatment may result in dramatic improvements in neurological function and limit the extent of brain damage even when the artery remains blocked.”

According to CoAxia, The most common event triggering a stroke is a sudden occlusion of a significant blood vessel in the brain – also known as a “brain attack” — which causes a lack of blood downstream from the blockage and leads to cell death in the brain and temporary or permanent neurological impairment commonly involving memory, speech and/or movement.

Stroke has a devastating effect on the victims’ ability to work and care for themselves and also presents a large cost burden to families and the healthcare system, the company noted.

The challenge in stroke treatment is that within minutes of an occlusion of a cerebral artery, brain cells begin to die, creating a non-salvageable region called the infarct core. Most strokes also involve a region of brain tissue, which is lacking sufficient oxygen for long-term survival, but can be saved if blood flow is restored or augmented, CoAxia said. This region, called the penumbra, is the target for all acute stroke treatments.

CoAxia considers its technology to be a potential alternative or complement to clot-focused techniques like pTA. Already somewhat active following an ischemic stroke, collateral pathways are capable of further increasing the delivery of oxygenated blood to the stroke’s ischemic penumbra.

The ability to salvage that penumbra and minimize the eventual size of the infarct may lead to improved neurological recovery, the company said.

CoAxia said it first tested the concept through animal experimentation, which demonstrated that partial aortic occlusion could be accomplished without significant side effects, cerebral perfusion could be rapidly and significantly increased, and the size of a resulting infarct could be reduced. In April 2002 the company began clinical studies in humans to demonstrate the safety of the procedure.

“We are pleased that Flo 24 enrollment is now underway at several of the top stroke institutions in North America,” said Andrew Weiss, president/CEO of CoAxia, “Together with our other studies, we are now evaluating our NeuroFlo technology in patients from 0-24 hours post stroke, representing a large segment of the annual ischemic strokes worldwide.”

CoAxia is a venture-backed, privately held, development-stage company focused on providing perfusion augmentation therapies that improve outcomes for patients with cerebral ischemia resulting from stroke, vasospasm and other conditions.

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