(State or Other Jurisdiction

of Incorporation

(Commission

File Number)

(IRS Employer

Identification No.)

60 Hampshire Street

Cambridge, MA

The previous by-laws provided that directors could be elected by consent of the stockholders in lieu of an annual meeting. This ability to elect directors by consent in lieu of an annual meeting has been eliminated. Other conforming changes have been made in the Revised By-Laws to account for this change.

The previous by-laws provided that holders of thirty-five percent (35%) or more of the issued and outstanding shares of common stock, par value $0.001, of the Company entitled to vote could call a special meeting of stockholders. Under the Revised By-Laws, special meetings of the stockholders can no longer be called by stockholders. Other conforming changes have been made in the Revised By-Laws to account for this change.

The previous by-laws were silent on the treatment of separate classes or series of capital stock with respect to the determination of a quorum. The Revised By-Laws set forth how such separate classes or series of capital stock will be treated for purposes of determining a quorum. Other conforming changes have been made in the Revised By-Laws to account for this change.

The previous by-laws did not require advanced notice with respect to any proposal that a stockholder wished to be considered at an annual meeting of stockholders, including nomination of directors. The Revised By-Laws provide that, under certain circumstances, advanced notice by the stockholder must be received no earlier than the 120^th day prior to such annual meeting and no later than the close of business on the later of (a) the 90^th day prior to the annual meeting and (b) the 10^th day following the date on which notice of the date of the annual meeting was mailed or public disclosure of the date of the annual meeting was made, whichever occurs first.

With respect to conduct of stockholders meetings, the Revised By-Laws state that with respect to the conduct of stockholder meetings (a) after the chairman of a meeting announces that the polls are closed, no additional ballots, proxies or votes or any revocations or changes thereto may be accepted and (b) one or more inspectors of election shall be appointed for stockholder meetings and that such inspector of elections shall have those duties proscribed by law. The previous by-laws did not include these requirements.

The previous by-laws did not include specific procedures relating to the manner of consent solicitations by stockholders. The Revised By-Laws specify detailed procedures relating to such consent solicitations.

The previous by-laws provided that notices of special meetings of the Board had to be provided at least 72 hours prior to any such meeting. The Revised By-Laws provide that such notices need to be provided at least 24 hours prior to such meeting.

The previous by-laws were silent on the ability of committees of the Board to create sub-committees. The Revised By-Laws permit committees of the Board to create sub-committees and delegate to such subcommittee any or all of the powers and authority of the committee.

The previous by-laws were silent with regards to the Board’s ability to delegate the powers or duties of any officer to any other officer or agent. The Revised By-Laws specify that the Board may delegate the powers or duties to any other officer or agent.

The previous by-laws included provisions related to transactions with interested parties. This provision has been eliminated in the Revised By-Laws in light of the fact that the Company operated under a separate Related Person Transaction Policy.

/s/ Maria Stahl

Maria Stahl

Senior Vice President and General Counsel

Exhibit No.

Description