SonoLysis^™ Program

Our SonoLysis program is focused on the development of two product candidates that involve the administration of our proprietary MRX-801 microbubbles and ultrasound with or without a thrombolytic drug to break up blood clots and restore blood flow to oxygen deprived tissues. SonoLysis+tPA therapy comprises the administration of MRX-801 microbubbles, ultrasound and the thrombolytic drug alteplase, or tPA. SonoLysis therapy comprises the administration of MRX-801 microbubbles and ultrasound without a thrombolytic drug. Our MRX-801 microbubbles are a proprietary formulation of a lipid shell encapsulating an inert biocompatible gas. We believe the sub-micron size of our MRX-801 microbubbles allows them to penetrate a blood clot, so that when ultrasound is applied their expansion and contraction, or cavitation, can break the clot into very small particles. We believe that these product candidates have the potential to treat a broad variety of vascular disorders associated with blood clots.

Our initial therapeutic focus for our SonoLysis program is ischemic stroke. The only approved drug for the treatment of ischemic stroke is tPA. tPA is restricted for use only to patients who are able to begin treatment within three hours of onset of symptoms of ischemic stroke and who do not have certain risk factors for bleeding, such as recent surgery or taking medications that prevent clotting. According to Datamonitor, approximately 23% of ischemic stroke patients arrive at a hospital within three hours of onset of symptoms. However, due to the three-hour window for treatment and other limitations, only 1.6% to 2.7% of patients with ischemic stroke in community hospitals, and only 4.1% to 6.3% in academic hospitals or specialized stroke centers are treated with thrombolytic therapy. For these patients who are eligible for treatment with tPA, we believe SonoLysis+tPA therapy may have advantages over tPA alone, including more rapid and complete restoration of blood flow. In addition, we believe our SonoLysis therapy may have an improved bleeding and safety profile over tPA and therefore may represent a new treatment option for ischemic stroke patients ineligible for tPA by extending the treatment window beyond three hours from onset of symptoms, as well as broadening treatment availability to patients for whom tPA is contraindicated due to risk of bleeding.

About Stroke

According to the American Heart Association, approximately one-third of adults in the United States have some form of cardiovascular disease. Over eight million people in the U.S. are afflicted each year with complications related to blood clots. Approximately 700,000 adults in the U.S., or one every 45 seconds, are afflicted with, and 150,000 die as a result of, some form of stroke each year. Stroke is currently the third leading cause of death, and the leading cause of disability, in the United States. Approximately three million Americans are currently disabled from stroke. The American Stroke Association estimates that approximately $62.7 billion will be spent in the U.S. in 2007 for stroke related medical costs and disability.

The vast majority of strokes, approximately 87% according to the American Stroke Association, are ischemic strokes, meaning that they are caused by blood clots, while the remainder are the more deadly hemorrhagic strokes caused by bleeding in the brain. Currently available treatment options for ischemic stroke are subject to significant therapeutic limitations. For example, the most widely used treatment for ischemic stroke is a clot-dissolving, or thrombolytic, drug that can be administered only during a narrow time window and poses a risk of bleeding, resulting in 6% or less of ischemic stroke patients receiving such treatment. To facilitate increased administration of stroke therapies, the American Stroke Association and related groups have urged the Centers for Medicare and Medicaid Services, or CMS, to create a new code to reimburse hospitals
at a higher rate for ischemic stroke patients treated with a thrombolytic drug. In 2005, in
response to requests by the American Stroke Association and related groups for higher
reimbursement amounts for ischemic stroke patients treated with a thrombolytic drug, the
CMS approximately doubled the amount of reimbursement provided for such treatment, to
$11,578 per patient.