JOINT FILING AGREEMENTJoint Filing Agreement • February 10th, 2010 • Biotechnology Value Fund L P • Investment advice
The undersigned hereby agree that the Statement on Schedule 13G dated February 10, 2010 with respect to the shares of Common Stock of ImmunoGen, Inc., and any further amendments thereto executed by each and any of the undersigned shall be filed on behalf of each of the undersigned pursuant to and in accordance with the provisions of Rule 13d-1(k)(1) under the Securities Exchange Act of 1934, as amended.
