ImaRx Therapeutics, the Redmond, WA-based developer of an ultrasound-based treatment for stroke, was crushed when news broke last year that three patients suffered brain hemorrhages in a clinical trial. But on further analysis of the data, the company says the therapy showed signs of being more effective than a standard clot-busting drug alone, at least when given at a low dose.
The results were from a trial, called Tucson, of 35 patients who took two different doses of the ImaRx treatment. The study was presented by researchers today at the American Stroke Association’s International Stroke Conference in San Diego. Researchers studied patients on the ImaRx method, which uses a combination of a standard clot-busting drug together with “lipid nanospheres” and ultrasound waves delivered to the brain. Patients on a low dose of the experimental treatment were about twice as likely to have their clogged arteries completely cleared than those who took the standard clot-busting drug, tPA, by itself.
The findings suggest that the ImaRx method, called SonoLysis, deserves to be tested further in a pivotal clinical trial to see if it can help stroke patients, said Dr. Andrei Alexandrov, director of the University of Alabama’s Comprehensive Stroke Center, in a company-issued statement. Alexandrov is a co-author of the study. Stroke is the third-leading cause of death in the U.S., killing 160,000 people each year, and the No. 1 cause of adult disability, according to the National Stroke Association.
“It’s very promising to see such results,” Alexandrov said in the statement.
Researchers found that 67 percent of patients on a low dose of ImaRx’s nanospheres had their arteries completely cleared out for a full 36 hours, compared with 46 percent who did that well on a higher dose, and 33 percent who got the standard clot-busting drug alone. Patients on the company’s treatment also had their blockages cleared out faster, in a median time of 30 minutes, compared with 60 minutes for those in the control group.
There is plenty of room to question the results, however. Not only did the lower dose work better than the high dose,
