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): December 31, 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.  ¨

Item 8.01       Other Events

The Board of Directors of Enzon Pharmaceuticals, Inc. (the “Company”), with respect to the fiscal year ended December 31, 2023, declared the payment of the 3% cash dividend to the holders of its 40,000 outstanding shares of Series C Non-Convertible Redeemable Preferred Stock (the “Series C Preferred Stock”) in an aggregate amount of $1,274,400, or $31.86 per share of Series C Preferred Stock. The dividends will be paid on January 17, 2024, to the holders of record of the Company’s Series C Preferred Stock as of January 10, 2024.

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.