Ultrasound and Clot-Busting Drug Effective for Stroke

The study revealed that patients could be treated safely with TCD in combination with a specific dose of the bubbles, called microspheres, and tPA.

The microspheres, developed by ImaRx Therapeutics (Redmond, WA, USA), are tiny gas-filled lipid structures that cavitate (rapidly expand and collapse) when exposed to ultrasound waves, helping to reopen blocked arteries and restore blood flow. "These findings demonstrate that ultrasound combined with microspheres and tPA can be tested further in a pivotal clinical trial with the goal of providing a more effective treatment option for stroke patients by promoting faster clearing of blocked blood vessels as well as improved patient outcomes,” said Alexandrov, UAB professor of neurology. "It's very promising to see such results, which support the potential of this therapy as a more effective and expansive therapy for stroke patients.”

The phase 1/2 trial involved 35 patients and evaluated two different doses of ImaRx's MRX-801 microspheres. Cohort I and cohort II patients received 1.4 ml and 2.8 ml of microspheres, respectively. Control patients received the standard dose of tPA alone.

The researchers reported that complete recanalization was achieved in 120 minutes in 67% of cohort I patients, in 46% of cohort II patients, and 33% of control patients. Dramatic clinical recovery was achieved in 45% of cohort I, 10% of
cohort II, and 27% of controls. Moreover, clinical improvement after 90 days was reported in 75% of cohort I, 50% of cohort II, and 36% of controls.

Stroke is the third-leading cause of death, and the leading cause of disability, in the United States. The vast majority of strokes 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.

Related Links:
University of Alabama at Birmingham
Vall d'Hebron Hospital
ImaRx Therapeutics