Exhibit 3.1

CERTIFICATE OF INCORPORATION

OF

MICROMET, INC.

1. Name. The name of the corporation is Micromet, Inc. (the “Corporation”).

2. Address; Registered Office and Agent. The address of the Corporation’s registered office in the State of Delaware is 2711 Centerville Road, Suite 400, Wilmington, New Castle, Delaware 19808. The name of its registered agent at such address is Corporation Service Company.

3. Purposes. The purpose of the Corporation is to engage in any lawful act or activity for which corporations may be organized under the DGCL.

4. Number of Shares. The total number of shares of stock that the Corporation shall have authority to issue is 1,000, all of which shall be shares of Common Stock with the par value of $0.0001 per share.

5. Election of Directors. Unless and except to the extent that the Bylaws of the Corporation (the “Bylaws”) shall so require, the election of directors of the Corporation need not be by written ballot. The number of directors of the Corporation shall be fixed from time to time by the board of directors pursuant to the Bylaws of the Corporation.

6. Limitation of Liability.

(a) To the fullest extent permitted under the General Corporation Law of the State of Delaware (the “DGCL”), as amended from time to time, no director of the Corporation shall be personally liable to the Corporation or its stockholders for monetary damages for breach of fiduciary duty as a director.

(b) Any amendment or repeal of Section 6(a) shall not adversely affect any right or protection of a director of the Corporation hereunder in respect of any act or omission occurring prior to the time of such amendment or repeal.

7. Adoption, Amendment or Repeal of ByLaws. The Board is authorized to adopt, amend or repeal the Bylaws.

8. Stockholder Actions. Any action required by law to be taken at any annual or special meeting of stockholders of the Corporation, or any action which may be taken at any annual or special meeting of such stockholders, may be taken without a meeting, without prior notice and without a vote, if a consent or consents in writing, setting forth the action so taken, shall be signed by the holders of outstanding stock having not less than the minimum number of votes that would be necessary to authorize or take such action at a meeting at which all shares entitled to vote thereon were present and voted.

9. Certificate Amendments. The Corporation reserves the right at any time, and from time to time, to amend or repeal any provision contained in this Certificate of Incorporation, and add other provisions authorized by the laws of the State of Delaware at the time in force, in the manner now or hereafter prescribed by applicable law; and all rights, preferences and privileges of whatsoever nature conferred upon stockholders, directors or any other persons whomsoever by and pursuant to this Certificate of Incorporation (as amended) are granted subject to the rights reserved in this Article.