UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

PURSUANT TO SECTION 13 OR 15(d)

OF THE SECURITIES EXCHANGE ACT OF 1934

Date of Report (Date of earliest event reported): January 19, 2018

ImmunoGen, Inc.

(Exact name of registrant as specified in its charter)

830 Winter Street, Waltham, MA 02451

(Address of principal executive offices)   (Zip Code)

Registrant’s telephone number, including area code: (781) 895-0600

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below):

o            Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

o            Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

o            Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

o            Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Indicate by check mark whether the registrant is a an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter.

Emerging growth company o

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. o

ITEM 5.02 — DEPARTURE OF DIRECTORS OR CERTAIN OFFICERS; ELECTION OF DIRECTORS; APPOINTMENT OF CERTAIN OFFICERS; COMPENSATORY ARRANGEMENTS OF CERTAIN OFFICERS

(a)  Not applicable.

(b)  Howard H. Pien, a director of ImmunoGen, Inc. (the “Company”), resigned from the Board of Directors, effective January 19, 2018.

(c)  Not applicable.

(d)  On January 23, 2018, the Board elected Stuart Arbuckle as a director to fill the vacancy created by Mr. Pien’s resignation from the Board.  Mr. Arbuckle will also serve as a member of the Governance and Nominating Committee of the Board of Directors.

A description of the compensation payable to Mr. Arbuckle for his service as a director is set forth in the Company’s definitive Proxy Statement dated April 28, 2017, filed with the Securities and Exchange Commission on April 28, 2017, under the caption “Director Compensation,” and is incorporated herein by reference.

(e)  Not applicable.

ITEM 9.01. FINANCIAL STATEMENTS AND EXHIBITS

(d): The following exhibit is being furnished herewith:

2

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the Registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

3

Exhibit 99.1

ImmunoGen Appoints Stuart A. Arbuckle to Board of Directors

WALTHAM, Mass., Jan. 24, 2018 — ImmunoGen, Inc. (Nasdaq: IMGN), a leader in the expanding field of antibody-drug conjugates (ADCs) for the treatment of cancer, today announced the appointment of Stuart A. Arbuckle to its Board of Directors. Mr. Arbuckle is replacing Howard Pien, who is stepping down from ImmunoGen’s Board after eight years of service.

“We are grateful for Howard’s many contributions to ImmunoGen over the last eight years,” stated Stephen McCluski, ImmunoGen’s Chairman of the Board. “His counsel on a range of strategic issues has been instrumental as we’ve strengthened our leadership in ADCs and progressed our pipeline of novel candidates through clinical development. We value Howard’s collaboration and contributions to the Board and wish him continued success in his endeavors outside of ImmunoGen.”

“Stuart joins ImmunoGen’s Board at a pivotal moment in the Company’s evolution,” Mr. McCluski continued. “His international commercial expertise will be vital as we continue to advance mirvetuximab soravtansine in the FORWARD I registration trial, accelerate the development of our earlier-stage ADC assets, and evolve into a business with marketed products.”

Mr. Arbuckle has more than 30 years of experience in building biopharmaceutical commercial organizations and has served as Vertex’s Executive Vice President and Chief Commercial Officer since 2012, leading the successful global launches of Kalydeco® and Orkambi®. Prior to joining Vertex, Mr. Arbuckle held multiple commercial leadership roles at Amgen, Inc., most recently serving as Vice President and Regional General Manager overseeing the expansion of the company’s presence in Japan, Asia, the Middle East, and Africa. As Vice President and General Manager of Amgen’s Oncology Business Unit, he was responsible for sales and marketing efforts for Aranesp®, Neulasta® and NEUPOGEN®, and led the successful launches of XGEVA® and Nplate®. Prior to Amgen, Mr. Arbuckle held commercial roles of increasing responsibility at Celltech Pharmaceuticals and GlaxoSmithKline. He also previously served as a member of Cerulean Pharma’s Board of Directors. He is currently a national board member of the Cancer Support Community, a member of the Executive Committee and Health Section Governing Board for the Biotechnology Innovation Organization (BIO), and is co-chair of the BIO Standing Committee on Access and Value. Mr. Arbuckle has a degree in pharmacology and physiology from the University of Leeds in the United Kingdom.

Mr. Arbuckle stated, “ImmunoGen embarked on a journey last year to focus on its highest value programs and develop into a fully integrated biotech company. I’m delighted to offer my insights and work with this Board as ImmunoGen drives long-term value creation and moves towards commercializing its first product.”

About ImmunoGen, Inc.

ImmunoGen is a clinical-stage biotechnology company that develops targeted cancer therapeutics using its proprietary ADC technology. The Company’s lead product candidate, mirvetuximab soravtansine, is in a Phase 3 trial for FRα-positive platinum-resistant ovarian cancer, and is in a Phase 1b/2 trial in combination regimens for earlier-stage disease. ImmunoGen has three additional clinical-stage product candidates, two of which are being developed in collaboration with Jazz Pharmaceuticals. ImmunoGen’s ADC technology is also used in Roche’s marketed product, Kadcyla®, and in programs in development by Amgen, Bayer, Biotest, CytomX, Debiopharm, Lilly, Novartis, Sanofi and Takeda. More information about the Company can be found at www.immunogen.com.

Kalydeco®, Orkambi®, Aranesp®, Neulasta®, NEUPOGEN®, XGEVA®, Nplate®, and Kadcyla® are registered trademarks of their respective owners.

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 risks related to preclinical and clinical studies, their timings and results. A review of these risks can be found in ImmunoGen’s Transition Report on Form 10-KT for the six-month transition period ended December 31, 2016 and other reports filed with the Securities and Exchange Commission.

For Investors

ImmunoGen, Inc.
Sarah Kiely, 781-895-0600
sarah.kiely@immunogen.com

For Media

ImmunoGen, Inc.
Courtney O’Konek, 781-895-0600
courtney.okonek@immunogen.com

Robert Stanislaro

FTI Consulting, Inc., 212-850-5657

robert.stanislaro@fticonsulting.com