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SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

(Name of Issuer)

(Title of Class of Securities)

(CUSIP Number)

(Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

Rule 13d-1(b)

Rule 13d-1(c)

Rule 13d-1(d)

SCHEDULE 13D/A 0000950123-08-002960 0000921669 XXXXXXXX LIVE 18 Common Stock, par value $0.01 per share 01/30/2026 false 0000727510 293904108 ENZON PHARMACEUTICALS, INC. 20 Commerce Drive (Suite 135) Cranford NJ 07016 Jesse Lynn, Esq. 305-442-4000 Icahn Capital LP, 16690 Collins Avenue Suite PH-1 Sunny Isles Beach FL 33160 Joshua Apfelroth 212-969-3000 Proskauer Rose LLP Eleven Times Square New York NY 10036 Louis Rambo 202-416-6800 Proskauer Rose LLP 1001 Pennsylvania Ave. NW, Suite 600 Washington DC 20004 0000921669 N CARL C ICAHN OO Y X1 0 36056636 0 36056636 36056636 N 48.6 IN The Reporting Person may also be deemed to beneficially own shares of Preferred Stock. 0001034563 N ICAHN ENTERPRISES HOLDINGS L.P. OO Y DE 0 36056636 0 36056636 36056636 N 48.6 PN The Reporting Person may also be deemed to beneficially own shares of Preferred Stock. 0001257324 N ICAHN ENTERPRISES G.P. INC. OO Y DE 0 36056636 0 36056636 36056636 N 48.6 CO The Reporting Person may also be deemed to beneficially own shares of Preferred Stock. Common Stock, par value $0.01 per share ENZON PHARMACEUTICALS, INC. 20 Commerce Drive (Suite 135) Cranford NJ 07016 This statement constitutes Amendment No. 18 to the Schedule 13D relating to the shares of Common Stock, par value $0.01 per share (the "Shares"), issued by Enzon Pharmaceuticals, Inc., a Delaware corporation (the "Issuer"), and amends the Schedule 13D relating to the Shares filed on March 14, 2008 (as previously amended, the "Original 13D"), on behalf of the Reporting Persons (as defined in Item 2 of Amendment No. 16 to the Schedule 13D). Capitalized terms used herein and not otherwise defined have the respective meanings ascribed thereto in the Original 13D. Item 4 of the Original 13D is hereby amended and supplemented as follows: The disclosure set forth in Item 6 of this Schedule 13D is incorporated herein by reference. Item 6 of the Original 13D is hereby amended and supplemented as follows: Pursuant to the previously disclosed IEH Support Agreement by and between Icahn Enterprises Holdings and certain of its affiliates, the Issuer and Viskase, on January 30, 2026, affiliates of Icahn Enterprises Holdings delivered to the Issuer a wirtten consent with respect to all of the issued and outstanding Shares held by such affiliates approving the Merger and the amendment to the Issuer's certificate of incorporation. CARL C ICAHN /s/ Carl C. Icahn Carl C. Icahn 01/30/2026 ICAHN ENTERPRISES HOLDINGS L.P. /s/ Ted Papapostolou Ted Papapostolou, Chief Financial Officer 01/30/2026 ICAHN ENTERPRISES G.P. INC. /s/ Ted Papapostolou Ted Papapostolou, Chief Financial Officer 01/30/2026