CAMBRIDGE, MA — September 2, 2004 – Momenta Pharmaceuticals, Inc. (Nasdaq: MNTA), a biotechnology company developing drugs based on sugar sequencing technology, announced today that its Chairman and Chief Executive Officer Alan Crane will present at the Bear Stearns 17th Annual Healthcare Conference on Monday September 13, 2004 at 3:45 pm Eastern Daylight Time at The Plaza Hotel, New York, New York.

A live audio webcast of this presentation will be available on the “Investors” section of the Company’s website located at www.momentapharma.com. A replay of the presentation will be posted on Momenta’s website approximately three hours after the event and will be available through December 12, 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. The Company’s most advanced product candidate is M-Enoxaparin, a technology-enabled generic version of Lovenox®. Based on its understanding of complex sugars, Momenta has created a diversified pipeline of novel discovery and development candidates. Momenta was founded in 2001 and is headquartered in Cambridge, MA.

To receive additional information about Momenta, please visit the website at www.momentapharma.com, which does not form a part of this press release.

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 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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