Less than a year after its last round of financing, Acusphere Inc. said it is bringing $20 million more on board.

The Watertown, Mass.-based company said the first closing of its eighth round netted more than $19 million, with the remainder of the funding commitment scheduled to close in June.

"We have very good technology, some good people and we've been hitting our milestones," John Thero, Acusphere's chief financial officer, told BioWorld Today. "In particular, we've just begun a Phase III trial of our lead product. That is something we're very excited about, and we have an exciting pipeline of additional technologies as well."

Last summer the privately held company closed a seventh round of financing worth $15 million, at the time bringing the total amount raised by Acusphere since its 1993 inception to about $77 million. (See BioWorld Today, July 26, 2002.)

For the most part, plans for the latest financial backing include funding for the recently begun Phase III trial of AI-700, an ultrasound contrast agent designed to detect coronary artery disease in ischemic heart disease patients. It is a dry powder made of perfluorocarbon gas-filled hollow microparticles mixed with sterile water and injected into the body by a single intravenous injection prior to ultrasound imaging.

"The idea is to look into the heart and see how it is performing, and we think we will be the first ones to do that," Thero said. "We got into the trial at the beginning of this year and it should complete enrollment within about a two-year period."

The company also plans to use the funding to continue development of other product candidates, including AI-128, its inhaled sustained-release asthma formulation that has completed Phase I studies. Pharmacokinetic analysis from the study demonstrated sustained levels of the drug in the blood over at least 12 hours.

"We believe that we have the first product that demonstrates sustained release of drugs in the lungs," Thero said.

AI-128 was developed with Dublin, Ireland-based Elan Corp. plc as part of a joint venture terminated in October in a cash-free transaction. Established in June 2000, the joint venture was formed to develop pulmonary drug delivery product candidates, though Elan's eventual restructuring efforts led to the breakup. Acusphere was assigned all intellectual property and development rights to product candidates developed by the joint venture, including AI-128, for which it agreed to pay Elan a royalty on certain revenues that may be realized.

Using its porous microparticle hydrophobic drug delivery system, or HDDS technology, Acusphere has advanced AI-850, a formulation of the cancer drug paclitaxel, into a Phase I trial. More specifically, the technology converts drugs with poor water solubility into tiny drug microparticles embedded in a porous, water-soluble, sponge-like matrix. It is developing AI-850 to enhance the tolerability of paclitaxel to enable use of higher doses of the drug. The product is the first HDDS-formulated candidate to enter clinical trials.

"We're trying to show two things - first, to be able to show that the core technology behind AI-850 has the ability to take drugs that aren't particularly soluble in water and improve their solubility," Thero said. "We're trying to show that we can get paclitaxel into the bloodstream more effectively, both in how quickly it dissolves and how well it is tolerated by the body."

Led by San Francisco-based Thomas Weisel Capital Partners LLC, other investors included BA Venture Partners, of Foster City, Calif.; Polaris Venture Partners, of Waltham, Mass.; BancBoston Ventures, of Boston; Audax Group, of Boston; Technology Funding Venture Capital, of El Dorado Hills, Calif.; Burr, Egan, Deleage & Co., of Boston; and HBM Bioventures, of Zurich, Switzerland.