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): June 8, 2023

ENZON PHARMACEUTICALS, INC.

(Exact name of registrant as specified in its charter)

(732) 980-4500

(Registrant’s telephone number, including area code)

Not Applicable

(Former name or former address, if changed since last report)

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:

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.  ¨

The 2023 virtual annual meeting of stockholders (the “Annual Meeting”) of Enzon Pharmaceuticals, Inc. (the “Company”) was held on June 8, 2023. At the Annual Meeting, the Company’s stockholders voted on the following matters as described in the Company’s proxy materials: (1) the election of three directors, each for a one-year term expiring at the Company’s next annual meeting of stockholders and until such director’s successor is elected and qualified, (2) the ratification of the appointment of EisnerAmper LLP as the Company’s independent registered public accounting firm for the fiscal year ending December 31, 2023, and (3) the approval, on an advisory basis, of the compensation of the Company’s named executive officer. A total of 55,089,122 shares of common stock were present or represented by proxy at the Annual Meeting, representing approximately 74% of the total shares of common stock entitled to vote. As such, a quorum was present.

The following is a brief description of each matter voted upon and the results, including the number of votes cast for and against each matter and, if applicable, the number of abstentions and broker non-votes with respect to each matter. Proxies for the Annual Meeting were solicited pursuant to Section 14(a) of the Securities Exchange Act of 1934, as amended, and there was no solicitation in opposition of management’s solicitation.

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.