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 presentations by Company management at upcoming investor conferences will be webcast:

• Leerink Global Healthcare Conference8:30 am ET, February 12 in New York, NY

• RBC Capital Markets’ 2015 Global Healthcare Conference8:30 am ET, February 24 in New York, NY

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

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, Novartis 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