ImmunoGen Announces Virtual 2020 Annual Meeting of Shareholders

ImmunoGen, Inc., (Nasdaq: IMGN), a leader in the expanding field of antibody-drug conjugates (ADCs) for the treatment of cancer, announced today that the 2020 Annual Meeting of Shareholders (the “Annual Meeting”) will be held virtually due to the public health impact of the coronavirus outbreak (COVID-19) and to support the health and well-being of the Company’s management, shareholders, and other meeting participants.

The Annual Meeting will be held on Wednesday, June 17, 2020 at 9:00 a.m. Eastern in a virtual format only. As described in the proxy materials for the Annual Meeting previously distributed, shareholders as of the close of business on April 13, 2020, the record date, are entitled to participate in the Annual Meeting. Shareholders who attend the virtual Annual Meeting by following the instructions below will have an opportunity to vote and to submit questions electronically during the meeting.

Shareholders will not be able to attend the Annual Meeting in person. Instead, shareholders can attend the Annual Meeting by accessing the meeting center at www.virtualshareholdermeeting.com/IMGN2020.

• Shareholders of Record: Shareholders of record at the close of business on April 13, 2020 (i.e., shares are held in the shareholder’s own name in the records of the Company’s transfer agent, Broadridge Corporate Issuer Solutions, Inc. (“Broadridge”)) can attend the virtual Annual Meeting by accessing the meeting center at www.virtualshareholdermeeting.com/IMGN2020 and entering the 16-digit control number on the proxy card or Notice Regarding the Availability of Proxy Materials previously received. Shareholders of record that have misplaced their control number can call Broadridge at [phone].

• Beneficial Owners: Beneficial owners of the Company’s common stock at the close of business on April 13, 2020 (i.e., shares are held by the shareholder’s broker in “street name”) can attend the Annual Meeting by accessing the meeting center at www.virtualshareholdermeeting.com/IMGN2020 and entering the 16-digit control number found on the notice and instructions received from their broker or other nominee.

If a shareholder does not have their 16-digit control number, the shareholder will be able to access and listen to the Annual Meeting as a guest, but the shareholder will not be able to vote their shares or submit questions during the Annual Meeting.