A Medical Device Daily

After halting a study earlier this month designed to evaluate a potential new stroke therapy, ImaRx Therapeutics (Tucson, Arizona) said Wednesday it is changing its focus to its urokinase product, rather than its Sonolysis program.

ImaRx had been developing Sonolysis — a potential new therapy that would use microbubbles and ultrasound to treat ischemic stroke. Earlier this month the company discontinued its Transcranial Ultrasound in Clinical Sonolysis (TUCSON) trial even though data from the trial had shown that patients could recover from ischemic stroke with the Sonolysis therapy combined with ultrasound. The trial was stopped because an undisclosed number of patients in one or two trial cohorts experienced intracranial hemorrhage events, possibly related to the use of tPA, the company said (Medical Device Daily, Jan. 7, 2008).

tPA, a clot-busting drug from Genentech (South San Francisco) has been the primary mode of ischemic stroke treatment, but it must be administered within three hours from when symptoms begin.

ImaRx said it recently signed a letter of intent with Microbix Biosystems (Toronto) to make a long-term urokinase supply, which will allow ImaRx to explore more therapeutic applications for the product. Urokinase, the company’s first FDA-approved product, is a thrombolytic or clot-dissolving agent indicated for the treatment of acute massive pulmonary embolism, or blood clots in the lungs.

While adjusting its focus to urokinase, ImaRx said it would still explore alternatives for “continued pursuit and financing” of its Sonolysis program.

“By focusing on broader commercial opportunities for urokinase, we believe we can unlock shareholder value and pursue a risk-mitigated corporate strategy overall,” said Bradford Zakes, president/CEO of ImaRx. “Currently, there exists only one other thrombolytic product approved in the U.S. for the treatment of acute massive pulmonary embolism. We believe the high regulatory hurdles and safety risks of other protein-derived thrombolytics have resulted in a number of failures in this product class in recent years. Based on the limited treatment options and ongoing demand for urokinase in the marketplace, we believe there exists an opportunity to significantly grow our urokinase product sales.”

Until now ImaRx’s business strategy had been focused primarily on developing its Sonolysis program for the treatment of ischemic stroke while monetizing its existing inventory of urokinase, the company said. Under that strategy, the company’s cash resources would have funded operations through 3Q08, but continuing Sonolysis trials would have necessitated the completion of a financing event prior to that date.

By transferring its Sonolysis development expenses to a third party and concentrating the company’s resources on urokinase, ImaRx expects to “significantly reduce” its operating capital requirements for 2008, according to Greg Cobb, the company’s CFO.