Now, ImaRx has received heavyweight validation for SonoLysis after signing an R&D collaboration with Philips Medical Systems, the Netherlands. Under the terms of the agreement, Philips will provide ultrasound devices and technical assistance to ImaRx during laboratory and preclinical studies. The objective is to determine the optimal ultrasound parameters to use with ImaRx's proprietary MRX-801 microbubble technology.

ImaRx's microbubbles are a proprietary formulation of a lipid shell encapsulating an inert biocompatible gas. The submicron bubbles penetrate the blood clot in such a way that when ultrasound is applied to the clot region it causes expansion, contraction and cavitation of the bubbles - processes that effectively "shake" the clot apart.

There are two variants of the treatment under study: SonoLysis+tPA therapy, which involves the administration of MRX-801 microbubbles, ultrasound and the thrombolytic drug alteplase (tPA); and SonoLysis therapy, which comprises the administration of microbubbles and ultrasound without a thrombolytic drug.

Bradford Zakes, president and CEO of ImaRx, described the tie-up with Philips as a "significant step forward [that] strengthens our position as we move further through our clinical trials".

The arrangement includes a mutual exclusivity clause covering the term of the collaboration. Following completion of the programme, however, Philips and ImaRx will have a defined negotiation period to discuss future development and commercialization.

Stroke is currently the third leading cause of death, and the leading cause of disability, in the US, according to the American Heart Association. Approximately 700,000 adults in the US are afflicted with, and 150,000 die as a result of, some form of stroke each year.