CAMBRIDGE, MA — July 23, 2004 – Momenta Pharmaceuticals, Inc. (NASDAQ: MNTA) announced today that its Chairman and Chief Executive Officer Alan Crane will present at the Banc of America Securities “New Products, New Paradigms in Health Care” Conference on Friday, July 30, 2004 at 11:45 am Eastern Standard Time at the Southampton Inn in Southampton, New York.

A live audio webcast of this presentation will be available on the “Investors” section of the Company’s website, www.momentapharma.com. A replay of the presentation will be posted on the Momenta website approximately three hours after the event and will be available through August 13, 2004.

About Momenta
Momenta Pharmaceuticals, Inc. is a biotechnology company specializing in the sequencing and engineering of complex sugars for the development of improved versions of existing drugs, the development of novel drugs and the discovery of new biological processes. Momenta is also utilizing its ability to sequence sugars to create technology-enabled generic products. Through precise chemical structure characterization and engineering of complex sugars, our proprietary technology provides a more complete understanding of the roles that sugars play in cellular function, disease and drug action. Based on Momenta’s understanding of complex sugars, the Company has developed a diversified pipeline of novel discovery and development candidates and near-term product opportunities. Momenta was founded in 2001 and is headquartered in Cambridge, MA.

Statements in this press release regarding future expectations, beliefs, goals, plans or prospects constitute forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Momenta’s actual results could differ materially from those stated or implied in forward-looking statements due to a number of factors, including those factors contained in Momenta’s final prospectus dated June 21, 2004 filed with the Securities and Exchange Commission in connection with Momenta’s initial public offering under the section “Risk Factors,” as well as other documents that may be filed by Momenta from time to time with the Securities and Exchange Commission. Forward-looking statements include statements regarding the Momenta’s expectations, beliefs, intentions or strategies regarding the future and can be identified by forward-looking words such as “anticipate”, “believe”, “could”, “estimate”, “expect”, “intend”, “may”, “should”, “will”, and “would” or similar words. Momenta assumes no obligations to update the information included in this press release.

Contact: Valerie Threlfall, Momenta Pharmaceuticals, Inc., 617-395-5116

Press Contact
press@momentapharma.com

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