ImmunoGen Announces Webcast of Presentation at the Jefferies Global Healthcare Conference

WALTHAM, Mass.–(BUSINESS WIRE)– ImmunoGen,
Inc. (Nasdaq: IMGN), a leader in the expanding field of
antibody-drug conjugates (ADCs) for the treatment of cancer, today
announced that Mark Enyedy, president and chief executive officer, will
present at the upcoming Jefferies 2017 Global Healthcare Conference in
New York, NY. The presentation is scheduled for 3:30 pm ET on June 8,
2017.

A webcast of the presentation 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 90
days.

About ImmunoGen, Inc.

ImmunoGen is a clinical-stage biotechnology company that develops
targeted cancer therapeutics using its proprietary ADC technology.
ImmunoGen’s lead product candidate, mirvetuximab soravtansine, is in a
Phase 3 trial for FRα-positive platinum-resistant ovarian cancer, and is
in Phase 1b/2 testing in combination regimens for earlier-stage disease.
ImmunoGen’s ADC technology is used in Roche’s marketed product, Kadcyla^®,
in three other clinical-stage ImmunoGen product candidates, and in
programs in development by partners Amgen, Bayer, Biotest, CytomX,
Lilly, Novartis, Sanofi and Takeda. 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.

This press release includes forward-looking statements. For these
statements, ImmunoGen claims the protection of the safe harbor for
forward-looking statements provided by the Private Securities Litigation
Reform Act of 1995. It should be noted that there are risks and
uncertainties related to the development of novel anticancer products,
including mirvetuximab soravtansine, including risks related to
preclinical and clinical studies, their timings and results. A review of
these risks can be found in ImmunoGen’s Annual Report on Form 10-K for
the fiscal year ended December 31, 2016 and other reports filed with the
Securities and Exchange Commission.

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