Lucky No. 7 rolled in for Acusphere Inc., which raised $15 million in its seventh round of financing.

"We think we have a pretty robust technology platform," Senior Vice President and Chief Financial Officer James Fitzgerald told BioWorld Today. "We've demonstrated a very flexible platform technology that can be used in a number of different forms, and we have a number of different products as well."

Though Fitzgerald declined to provide a specific valuation for the privately held specialty pharmaceutical firm, he said Acusphere has raised $80 million since its founding in 1993.

The Watertown, Mass.-based company develops new drugs and improved formulations of existing drugs through its porous microparticle technology. Acusphere said it plans to use the proceeds to continue clinical development of its three porous product candidates.

AI-700, Acusphere's ultrasound contrast agent that uses audio imaging to detect blood insufficiency in the heart muscle, has completed two Phase II trials. Already studied in 200 patients, the contrast agent is a dry powder made of hollow microparticles filled with a perfluorocarbon gas. They are mixed with sterile water and injected into the body by a single intravenous injection prior to ultrasound imaging.

"We believe it's going to be in Phase III toward the end of this year," Fitzgerald said, adding that the company expects to meet with the FDA to finalize Phase II data later this year.

The 55-employee company also plans to continue development of product candidates using its porous microparticle hydrophobic drug delivery system, or HDDS, technology, which it labels as applicable as a pulmonary drug delivery system, as an intravenous gas delivery system for ultrasound contrast, and as a hydrophobic drug delivery system.

"A couple of years ago, we recognized the applicability of the basic technology to other areas of drug delivery," Fitzgerald said. "We built a hydrophobic drug delivery platform technology, which basically uses the same technology, but by changing the types of polymers we use in the formulation we are able to create microparticles that have imbedded drugs."

Phase I trials began in May of its inhaled sustained-release asthma formulation as well as for AI-850, a formulation of the cancer drug paclitaxel.

The microparticle formulation of an inhaled asthma drug is the first candidate to enter trials under a joint venture with Elan Corp. plc, of Dublin, Ireland, which was formed to develop and commercialize a portfolio of inhalation products for local and systemic lung delivery. Acusphere's formulation is designed to slowly release the asthma drug, thereby reducing multidosing to a once-daily regimen.

Acusphere is developing AI-850 to enhance the tolerability of paclitaxel to enable use of higher doses of the drug. AI-850 is the first product candidate to enter trials that has been formulated using its HDDS, which converts drugs with poor water solubility into tiny drug microparticles embedded in a porous, water-soluble, sponge-like matrix.

"In animals, we have shown that we get a much more rapid absorption of paclitaxel than Taxol does, and we've avoided cremaphor, which is somewhat of a toxin oil," Fitzgerald said. "Using our system, we can get paclitaxel absorbed virtually to 100 percent within minutes."

Led by San Francisco-based Thomas Weisel Capital Partners LLC, other investors included Foster City, Calif.-based BA Venture Partners; Polaris Venture Partners, of Waltham, Mass.; San Francisco-based Alta Ventures; MVI Medical Ventures Investments Ltd., of Basel, Switzerland; Westwood, Mass.-based Prism Venture Partners; BancBoston Ventures, of Boston; Audax Group, of Boston; El Dorado Hills, Calif.-based Technology Funding Venture Capital; Boston University; and New York-based CIT Group Inc.