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): February 7, 2024

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):

Securities registered pursuant to Section 12(b) of the Act:

Indicate by check mark whether the registrant is 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 ¨

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. ¨

As previously disclosed, on November 30, 2023, ImmunoGen, Inc., a Massachusetts corporation (the “Company” or “ImmunoGen”), entered into an Agreement and Plan of Merger (the “Merger Agreement”) with AbbVie Inc., a Delaware corporation (“AbbVie”), Athene Subsidiary LLC, a Delaware limited liability company and wholly owned subsidiary of AbbVie (“Intermediate Sub”), and Athene Merger Sub Inc., a Massachusetts corporation and wholly owned subsidiary of Intermediate Sub (“Purchaser”), pursuant to which, upon the terms and subject to the conditions set forth therein, Purchaser will be merged with and into the Company (the “Merger”), with the Company surviving the Merger as a subsidiary of Intermediate Sub.

The consummation of the Merger is conditioned upon, among other things, the expiration or termination of any waiting periods applicable to the Merger under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended (the “HSR Act”). ImmunoGen and AbbVie each filed a Notification and Report Form pursuant to the HSR Act with respect to the Merger with the U.S. Federal Trade Commission (the “FTC”) and the U.S. Department of Justice on January 8, 2024. The 30-day waiting period imposed by the HSR Act in connection with the Merger expired at 11:59 p.m. on February 7, 2024, without action by the FTC.

The Company expects the closing of the transactions contemplated by the Merger Agreement to occur on or about February 12, 2024.

Cautionary Statement Regarding Forward-Looking Statements

This Current Report on Form 8-K includes forward-looking statements that are subject to risks, uncertainties and other factors that could cause actual results to differ materially from those implied by the forward-looking statements. All statements other than statements of historical fact are statements that could be deemed forward-looking statements, including all statements regarding the intent, belief or current expectation of ImmunoGen and members of its senior management team and can typically be identified by words such as “believe,” “expect,” “estimate,” “predict,” “target,” “potential,” “likely,” “continue,” “ongoing,” “could,” “should,” “intend,” “may,” “might,” “plan,” “seek,” “anticipate,” “project” and similar expressions, as well as variations or negatives of these words. Forward-looking statements include, without limitation, the expected timing of the completion of the transaction and the accuracy of any assumptions underlying any of the foregoing. Investors are cautioned that any such forward-looking statements are not guarantees of future performance and involve risks and uncertainties and are cautioned not to place undue reliance on these forward-looking statements. Actual results may differ materially from those currently anticipated due to a number of risks and uncertainties. Risks and uncertainties that could cause the actual results to differ from such expectations contemplated by forward-looking statements include, but are not limited to: uncertainties as to the timing of the Merger; the occurrence of any event, change or other circumstance that could give rise to the termination of the Merger Agreement, including circumstances requiring a party to pay the other party a termination fee pursuant to the Merger Agreement; the ability of the parties to consummate the Merger on a timely basis or at all, and other risks and uncertainties detailed from time to time in documents filed with the Securities and Exchange Commission (the “SEC”) by ImmunoGen, including current reports on Form 8-K, quarterly reports on Form 10-Q and annual reports on Form 10-K. All forward-looking statements in this Current Report on Form 8-K are based on information currently available to ImmunoGen. ImmunoGen assumes no obligation to update any forward-looking statement, whether as a result of new information, future developments, or otherwise, except as may be required by applicable law. The information set forth herein speaks only as of the date hereof.

These may not be all of the factors that could cause actual results to vary materially from the forward-looking statements. ImmunoGen shareholders are advised to consult any future disclosures that we make on related subjects as may be detailed in our other filings made from time to time with the SEC.

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.

Date: February 8, 2024