Acusphere Takes Occupancy of Commercial Manufacturing Facility in Tewksbury, Massachusetts.

WATERTOWN, Mass. -- Acusphere, Inc. (NASDAQ: ACUS), a specialty pharmaceutical company that develops drugs using its porous microparticle technology, announced today that it has taken occupancy of its commercial manufacturing facility in Tewksbury, Massachusetts. Over the past year, Acusphere has been converting an existing pharmaceutical manufacturing facility within 25 miles of the Company's Watertown, Massachusetts headquarters to manufacture its lead product candidate.

Engineering, design and construction of this facility began under a contract entered into in November 2004. Acusphere recently received an occupancy permit for this built-out facility. The Company is now focusing on the next stage of the project: the start-up and qualification of AI-700 operations within the facility, in accordance with current good manufacturing practices (cGMPs).

"We are very pleased with the progress we have made in constructing a facility designed for AI-700," commented Sherri C. Oberg, President and CEO of Acusphere. "We believe that this facility will provide us with the commercial scale production capability necessary to effectively launch AI-700 throughout the United States and, through partners, worldwide."

An estimated 10.7 million procedures in the U.S. and more than 1.0 million procedures in Europe are performed each year to screen patients with suspected coronary heart disease, primarily using nuclear imaging. AI-700-enhanced ultrasound is being developed as a cost-effective and convenient alternative to nuclear imaging.

About Acusphere, Inc.

Acusphere (NASDAQ: ACUS) is a specialty pharmaceutical company that develops new drugs and improved formulations of existing drugs using its proprietary microparticle technology. Acusphere's three initial product candidates for which it has clinical data are designed to address unmet clinical needs within cardiology, oncology and asthma. Acusphere's lead product candidate, AI-700, is a cardiovascular drug in Phase 3 clinical development. An estimated 10.7 million procedures are performed each year in the U.S. to detect coronary heart disease, the leading cause of death in the United States. Acusphere's product candidates have been created using proprietary technology that enables Acusphere to control the porosity and size of nanoparticles and microparticles in a versatile manner that enables particles to be customized to address the delivery needs of a variety of drugs. For more information about Acusphere visit the Company's web site at www.acusphere.com.

"Acusphere" is a trademark of Acusphere, Inc.

Forward-looking Statements 

This Release contains forward-looking statements, including statements regarding the qualification and capacity of its manufacturing facility and the effective commercial launch of AI-700. The Company's actual results and trading in shares of the Company's stock may differ materially from that anticipated in these forward-looking statements based upon a number of factors, including anticipated operating losses, uncertainties associated with research, development, testing and related regulatory approvals, including uncertainties regarding the ultimate outcome of Acusphere's Phase 3 clinical trials for AI-700, unproven markets, future capital needs and uncertainty of additional financing, competition, uncertainties associated with intellectual property, complex manufacturing, high quality requirements, dependence on third-party manufacturers, suppliers and collaborators, loss of key personnel, lack of sales and marketing experience, uncertainties associated with market acceptance and adequacy of reimbursement, technological change and government regulation, and other potential risks and challenges. Further details regarding potential risks and challenges are detailed in the Company's filings with the U.S. Securities and Exchange Commission, including the Company's Quarterly Report on Form 10-Q for the quarter ended June 30, 2005. Readers are cautioned not to place undue reliance on any forward-looking statements, which speak only as of the date of this Release. The Company undertakes no obligation to publicly release the results of any revisions to these forward-looking statements that may be made to reflect events or circumstances that occur after the date of this Release or to reflect the occurrence of unanticipated events.