EKOS Technology Featured At Stroke Conference; Adding Ultrasound to Clot Dissolving Drugs Cited As Promising New Treatment Strategy.

NASHVILLE, Tenn.--(BW HealthWire)--Feb. 1, 1999--Using EKOS' ultrasound-enhanced drug delivery systems to administer clot-dissolving drugs could help improve treatment for stroke victims, according to a leading clinical researcher speaking here at the annual meeting of the American Society of Interventional and Therapeutic Neuroradiology.

Delivering a presentation on emerging technologies for the treatment of acute stroke, Stanley Barnwell, M.D., Ph.D., associate professor of neurosurgery at Oregon Health Sciences University, pointed to EKOS' active drug delivery technology as one of the exciting strategies now under development for this common and devastating condition. In the past few years, clot dissolving agents have become one of the most important treatments for combatting stroke, an event that is most often caused by a blood clot in a brain artery. EKOS' proprietary system will take this approach one step further, simultaneously delivering ultrasound and clot-dissolving agents into a blood vessel near the blockage. Laboratory research has indicated that the combination of ultrasound and clot dissolvers, also called thrombolytics, may result in more rapid and more complete clot dissolution compared with the use of drug alone. This is likely due to the ability of ultrasound to move drug deeper into the clot where the treatment can work more effectively.

"Clot-dissolving drugs have helped revolutionize the way we treat stroke, but rapid restoration of blood flow remains a critical factor in minimizing permanent disability," Dr. Barnwell said. "Approaches such as EKOS' that have the potential to improve the rate and degree of clot dissolution could be very important in achieving the best results for these patients."

When a brain artery becomes blocked, it is essential to quickly reestablish blood flow, because the longer the brain is deprived of blood, the more tissue that dies. To treat stroke, clot dissolvers have generally been administered systemically, that is, injected into a distant vein and then carried in the bloodstream to the area of the clot. Researchers now have begun studying the utility of local drug administration, whereby the drug is delivered right to the site of the blockage through a catheter placed in the diseased artery. The potential advantages of this approach are that, by putting the drug directly where it's needed, blood flow is restored more rapidly and less drug is used, thereby improving outcome while causing fewer side effects.

A large trial to investigate the use of local thrombolytic therapy in stroke has recently been completed. This study, called ProAct (Prourokinase in Acute Cerebral Thromboembolism), did not look at EKOS' ultrasound-drug combination, but did evaluate delivering drug directly to the clot. Results from the ProAct pilot study, which were published last year, indicated that local administration of clot-dissolvers is feasible and effective. Data from the full trial are expected to be presented later this week at the American Heart Association's International Conference on Stroke and Cerebral Circulation.

EKOS believes that its ultrasound-enhanced drug delivery technology can build on the results seen in stroke with use of local thrombolytic drugs alone. The company currently has a preclinical research program underway as a prerequisite to beginning human trials for this indication. Stroke is the second developmental initiative that EKOS has launched. It recently began human studies to evaluate the use of a similar ultrasound delivery system in the treatment of blocked leg arteries.

"Stroke is a major focus for EKOS," said Thomas M. Keenan, president and chief executive officer. "It marks an expansion of our accelerated thrombolysis program and, in fact, may represent the most significant market potential for the company among our early commercialization targets."

EKOS Corporation, located in Bothell, Washington, develops proprietary ultrasound-based systems and devices for local drug delivery. Such "active drug delivery" is designed to enhance drug action, reduce dosage requirements and toxicity, and deliver drugs to areas where none can effectively penetrate with standard techniques. This novel use of ultrasound energy for therapeutic, rather than diagnostic, purposes has the potential to reduce treatment times, improve outcomes, and offer new or expanded treatment options in a wide range of diseases. The company's first products will focus on the treatment of cardiovascular obstructive disease, including stroke and arterial thrombosis.