Less than a year after raising $5 million to advance its nanotechnology-based therapy program, ImaRx Therapeutics Inc. completed an additional $7 million private placement to fund clinical trials of its SonoLysis technology, which uses nanobubbles and ultrasound to dissolve blood clots.

Proceeds also will be used to add a key business development position, a chief operating officer and possibly a chief medical officer, said John Moore, chairman and executive vice president of ImaRx. He added that the company also would be repurchasing debt from a former pharmaceutical partner.

The company completed the placement of 2.3 million shares of common stock to private investors, with First Montauk Securities Corp., of Red Bank, N.J., acting as the placement agent for the financing. The financing is expected to sustain the company until October.

Though nanotechnology-based platforms have been used for diagnostic purposes, ImaRx's SonoLysis technology is the first designed for therapeutic indications, Moore said. SonoLysis uses the company's MRX-815 nanobubbles plus ultrasound to target and dissolve blood clots without invasive surgery or systemic drug products.

ImaRx's CEO developed the first injectable microbubble in the 1990s. It was first created as a diagnostic tool, an imaging agent called Definity, later marketed by New York-based Bristol-Myers Squibb Co. Definity received FDA approval in 2001.

"Dr. Unger retained the therapeutic rights to the microbubbles," Moore told BioWorld Today, describing the microbubbles as "lipid-coated shells with gas on the inside that pulsates and pumps when in contact with ultrasound."

Smaller than red blood cells, the microbubbles are injected into the site of the blood clot and can be used alone or in combination with an administered thrombolytic drug, such as South San Francisco-based Genentech Inc.'s tPA product, tenecteplase, to cause a "stirring motion" that quickly dissolves the clot without causing any systemic effects.

"It's localized, targeted and we hope to prove in clinical trials that it's safe and effective," Moore said. "We hope we can give a tool to neurologists and emergency room doctors that can dissolve a clot quickly and preserve as much of the brain as possible."

He added that using a tPA product alone usually requires anywhere from 24 hours to 72 hours to dissolve a clot, and only a small percentage of stroke patients can receive tPA without serious risk.

If ImaRx's NanoInvasive technology is approved for blood clots and other potential indications, it could end up reducing health care costs by "cutting down on side effects and hospital stays," Moore said.

Funds from the recent financing will help pay for a Phase II trial in stroke patients set to begin next quarter, though the company anticipates investigating SonoLysis and the MRX-815 nanobubbles in a number of different indications.

"We're just about to release data from our dialysis graft trials," he said, which represents the "first use of microbubbles in humans" for thrombosis.

The product is in Phase I/II trials for deep-vein thrombosis, and ImaRx also has filed an expanded investigational new drug application to include peripheral arterial occlusions. Preclinical studies are ongoing in myocardial infarction, and Moore said the company's technology has been shown in animal models to be effective in gene therapy and drug delivery, as well.

The company initially was founded by Unger in the early 1990s as ImaRx Pharmaceuticals. After three imaging agents, including Definity, were approved by the FDA and licensed to other companies for marketing, Unger paid off investors and restarted the company as ImaRx Therapeutics in 2000. Since that time, ImaRx has raised a total of $23.5 million.

The Tucson-based company has about 25 employees, though Moore said an additional 10 are expected to be added as the company advances its products into late-stage clinical development.

With more than 100 U.S. patents, ImaRx's nanotechnology-based platform has promise.

"We hope to do for drugs what companies like Boston Scientific have done for medical devices," he said.