Acusphere to Present at MASS Opportunities Biotechnology Investor Conference.

WATERTOWN, Mass. -- Acusphere, Inc. (NASDAQ: ACUS) announced today that it is scheduled to make an investor presentation at the MASS Opportunities Biotechnology Investor Conference, organized by the Massachusetts Biotechnology Council, at 9:50 AM (EST) on Thursday, November 4, 2004 in Boston. Presenting for the company will be John F. Thero, Senior Vice President and Chief Financial Officer. The presentation will include an overview of the company and a review of corporate goals.

A webcast of the Company's presentation will be available both live and on a recorded basis via a link provided at the company's website www.acusphere.com on the Investor Relations page. The recording will be available through November 19, 2004.

About Acusphere, Inc.

Acusphere 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 are in clinical development and are designed to address large unmet clinical needs within cardiology, oncology and asthma. These product candidates were created using proprietary technology that enables Acusphere to control the porosity and size of nanoparticles and microparticles in a versatile manner that allows particles to be customized to address the delivery needs of a variety of drugs. Acusphere's lead product candidate, AI-700, is a cardiovascular drug in Phase III clinical development. AI-700 is designed to be a preferred alternative to the estimated 9.5 million procedures done each year in the U.S. to detect coronary artery disease, the leading cause of death in the United States. For more information about Acusphere visit the Company's web site at www.acusphere.com.

The presentation to be made at the above announced conference may contain forward-looking statements, including statements regarding the successful and timely completion of clinical trials, future financing needs, commercial prospects for the Company's product candidates and technology and prospects for new partnering and business relationships. The Company's actual results may differ materially from those 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, 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, lack of sales and marketing experience, loss of key personnel, uncertainties associated with market acceptance and adequacy of reimbursement, technological change and government regulation, and other risks and challenges 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 period ending June 30, 2004. 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.