CAMBRIDGE, MA — July 28, 2006 – Momenta Pharmaceuticals, Inc. (Nasdaq: MNTA), a biotechnology company developing drugs based on its proprietary sugar sequencing technology, will report its financial results for the second quarter ended June 30, 2006 before the U.S. financial markets open on Tuesday, August 8, 2006.

Management will host a conference call on that date at 10:00 am EDT to discuss these results and provide an update on the company. To access the call, please dial 866-271-5140 (domestic) or 617-213-8893 (international) prior to the scheduled conference call time and provide the access code 93739519. A replay of the call will be available approximately two hours after the call and will be accessible through August 15, 2006. To access the replay, please dial 888-286-8010 (domestic) or 617-801-6888 (international) and provide the access code 82360896.

A live audio webcast of the call will be available on the “Investors” section of the Company’s website, www.momentapharma.com. Please go to the site at least 15 minutes prior to the call in order to register, download, and install any necessary software. An archived version of the webcast will be posted on the Momenta website approximately two hours after the call and will be available through September 8, 2006.

About Momenta:
Momenta Pharmaceuticals is a biotechnology company specializing in the detailed characterization and engineering of complex sugars. Momenta is applying its technology to create technology-enabled generic versions of sugar-based and other complex drug products, as well as improved and novel drug candidates. The Company’s most advanced product candidate is M-Enoxaparin, a technology-enabled generic version of Lovenox®. An ANDA was filed for M-Enoxaparin in August 2005 in collaboration with Sandoz, the generics division of Novartis AG. Momenta has multiple technology-enabled generic products in its pipeline. Momenta’s first improved drug candidate is M118, a rationally engineered anticoagulant specifically designed for acute coronary syndromes. The Company is also developing novel drug candidates through its discovery effort focused on understanding novel sugar-based biological processes. Momenta was founded in 2001 based on technology initially developed at Massachusetts Institute of Technology 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.

Our logo, trademarks, and service marks are the property of Momenta Pharmaceuticals, Inc. All other trade names, trademarks, or service marks are property of their respective owners.

Contact:
Michael A. Lawless
Momenta Pharmaceuticals, Inc.
617-395-5189

Press Contact
press@momentapharma.com

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