ImmunoGen, Inc. Announces Conference Call to Discuss its Third Quarter Fiscal Year 2015 Financial Results

ImmunoGen, Inc. (Nasdaq: IMGN), a biotechnology company that develops novel anticancer therapeutics using its antibody-drug conjugate (ADC) technology, today announced that the Company will host a conference call at 8:00 a.m. ET on Friday, April 24, 2015, to discuss ImmunoGen's financial results for the three-month period ended March 31, 2015, the third quarter of its 2015 fiscal year. Management will also provide an update on the Company and the financial guidance.

To access the live call by phone, dial 913-312-0966; the conference ID is 2370723. The call also may be accessed through the Investors section of the Company's website, www.immunogen.com. Following the live webcast, a replay of the call will be available at the same location through May 8, 2015.

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 utilizes its ADC technology with its antibodies to create ImmunoGen product candidates and also out-licenses limited rights to use its technology to other companies. Roche’s Kadcyla® is the first marketed product with ImmunoGen’s ADC technology. More information about the Company 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