On June 13, 2012, Momenta Pharmaceuticals, Inc. (the "Company") held its 2012 Annual Meeting of Stockholders (the "Annual Meeting") at the Cambridge Marriott, located at 50 Broadway, Cambridge, MA. A total of 51,502,404 shares of the Company's common stock were entitled to vote as of April 16, 2012, the record date for the Annual Meeting, of which 47,882,841 were present in person or by proxy at the Annual Meeting. The votes cast with respect to each item of business properly presented at the meeting are as follows:

1. The stockholders elected each of the three Class II nominees to the Company's Board of Directors to hold office until the 2015 Annual Meeting of Stockholders by a plurality of the votes duly cast.

                      For       Withheld    Broker Non-Votes
John K. Clarke     35,455,694   3,667,679          8,759,468
James R. Sulat     35,787,235   3,336,138          8,759,468
Craig A. Wheeler   36,119,835   3,003,538          8,759,468

2. The stockholders ratified the appointment of Ernst & Young LLP as the Company's independent registered accounting firm for the fiscal year ending December 31, 2012 by a majority of the votes duly cast.

For:       44,334,340
Against:      155,483
Abstain:    3,393,018

3. A non-binding "say on pay" advisory proposal on the compensation of the Company's named executive officers was approved.

For:                35,592,230
Against:             3,351,205
Abstain:               179,938
Broker Non-Votes:    8,759,468