ImmunoGen, Inc. Announces Webcast of Presentations at Upcoming Investor Conferences

ImmunoGen, Inc. (Nasdaq: IMGN), a biotechnology company that develops novel anticancer therapeutics using its antibody-drug conjugate (ADC) technology, today announced that the following presentation by Company management at an upcoming investor conference will be webcast:

• 34th Annual Canaccord Genuity Growth Conference3:30pm ET, August 13, Boston, MA

The webcast will be accessible live through the “Investor Information” section of the Company’s website, www.immunogen.com; a replay will be available at the same location for approximately a week.

The Company is also participating in the UBS 2014 Biotech Summer 1x1 Conference August 7, 2014 in Boston, MA.

About ImmunoGen, Inc.

ImmunoGen, Inc. develops targeted anticancer therapeutics. The Company’s ADC technology uses tumor-targeting antibodies to deliver an ImmunoGen cell-killing agent specifically to cancer cells; the Company has also developed antibodies with anticancer activity of their own. The first product with ImmunoGen’s ADC technology is Roche’s Kadcyla®. ImmunoGen has three wholly owned product candidates in clinical testing with additional compounds in clinical testing through the Company’s partnerships with Amgen, Bayer HealthCare, Biotest and Sanofi. More information about ImmunoGen can be found at www.immunogen.com.

Kadcyla® is a registered trademark of Genentech, a member of the Roche Group.

For Investors:ImmunoGen, Inc.Carol Hausner, [e-mail] Media:Pure Communications, Inc.Dan Budwick, 973-271-6085