UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 ---------------------- SCHEDULE 13G Under the Securities Exchange Act of 1934 Enzon Pharmaceuticals, Inc. (Name of Issuer) Common Stock (Title of Class of Securities) 293904108 (CUSIP Number) May 18, 2006 (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) [X] Rule 13d-1(c) [ ] Rule 13d-1(d) ---------------- *The remainder of this cover page shall be filled out for a reporting person's initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter the disclosures provided in a prior cover page. The information required in the remainder of this cover page shall not be deemed to be "filed" for purpose of Section 18 of the Securities Exchange Act of 1934 ("Act") or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes). Page 1 of 17 Pages CUSIP No. 293904108 13G Page 2 of 17 Pages -------------------------------------------------------------------------------- (1) NAMES OF REPORTING PERSONS I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS Highbridge International LLC -------------------------------------------------------------------------------- (2) CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP ** (a) [X] (b) [ ] -------------------------------------------------------------------------------- (3) SEC USE ONLY -------------------------------------------------------------------------------- (4) CITIZENSHIP OR PLACE OF ORGANIZATION Cayman Islands, British West Indies -------------------------------------------------------------------------------- NUMBER OF (5) SOLE VOTING POWER 0 SHARES _________________________________________________________________ BENEFICIALLY (6) SHARED VOTING POWER 4.0% Convertible Senior Notes, due 2013, convertible into 3,455,496 shares of Common Stock 235,656 shares of Common Stock OWNED BY _________________________________________________________________ EACH (7) SOLE DISPOSITIVE POWER 0 REPORTING _________________________________________________________________ PERSON WITH (8) SHARED DISPOSITIVE POWER 4.0% Convertible Senior Notes, due 2013, convertible into 3,455,496 shares of Common Stock 235,656 shares of Common Stock -------------------------------------------------------------------------------- (9) AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 4.0% Convertible Senior Notes, due 2013, convertible into 3,455,496 shares of Common Stock 235,656 shares of Common Stock -------------------------------------------------------------------------------- (10) CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES ** [ ] -------------------------------------------------------------------------------- (11) PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) 7.8% -------------------------------------------------------------------------------- (12) TYPE OF REPORTING PERSON ** OO -------------------------------------------------------------------------------- ** SEE INSTRUCTIONS BEFORE FILLING OUT! CUSIP No. 293904108 13G Page 3 of 17 Pages -------------------------------------------------------------------------------- (1) NAMES OF REPORTING PERSONS I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS Highbridge Capital Corporation -------------------------------------------------------------------------------- (2) CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP ** (a) [X] (b) [ ] -------------------------------------------------------------------------------- (3) SEC USE ONLY -------------------------------------------------------------------------------- (4) CITIZENSHIP OR PLACE OF ORGANIZATION Cayman Islands, British West Indies -------------------------------------------------------------------------------- NUMBER OF (5) SOLE VOTING POWER 0 SHARES _________________________________________________________________ BENEFICIALLY (6) SHARED VOTING POWER 4.0% Convertible Senior Notes, due 2013, convertible into 3,455,496 shares of Common Stock 235,656 shares of Common Stock OWNED BY _________________________________________________________________ EACH (7) SOLE DISPOSITIVE POWER 0 REPORTING _________________________________________________________________ PERSON WITH (8) SHARED DISPOSITIVE POWER 4.0% Convertible Senior Notes, due 2013, convertible into 3,455,496 shares of Common Stock 235,656 shares of Common Stock -------------------------------------------------------------------------------- (9 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 4.0% Convertible Senior Notes, due 2013, convertible into 3,455,496 shares of Common Stock 235,656 shares of Common Stock -------------------------------------------------------------------------------- (10) CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES ** [ ] -------------------------------------------------------------------------------- (11) PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) 7.8% ________________________________________________________________________________ (12) TYPE OF REPORTING PERSON ** OO -------------------------------------------------------------------------------- ** SEE INSTRUCTIONS BEFORE FILLING OUT! CUSIP No. 293904108 13G Page 4 of 17 Pages -------------------------------------------------------------------------------- (1) NAMES OF REPORTING PERSONS I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS Highbridge Capital L.P. -------------------------------------------------------------------------------- (2) CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP ** (a) [X] (b) [ ] -------------------------------------------------------------------------------- (3) SEC USE ONLY -------------------------------------------------------------------------------- (4) CITIZENSHIP OR PLACE OF ORGANIZATION State of Delaware -------------------------------------------------------------------------------- NUMBER OF (5) SOLE VOTING POWER 0 SHARES ________________________________________________________________ BENEFICIALLY (6) SHARED VOTING POWER 4.0% Convertible Senior Notes, due 2013, convertible into 3,455,496 shares of Common Stock 235,656 shares of Common Stock OWNED BY _________________________________________________________________ EACH (7) SOLE DISPOSITIVE POWER 0 REPORTING _________________________________________________________________ PERSON WITH (8) SHARED DISPOSITIVE POWER 4.0% Convertible Senior Notes, due 2013, convertible into 3,455,496 shares of Common Stock 235,656 shares of Common Stock -------------------------------------------------------------------------------- (9) AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 4.0% Convertible Senior Notes, due 2013, convertible into 3,455,496 shares of Common Stock 235,656 shares of Common Stock -------------------------------------------------------------------------------- (10) CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES ** [ ] -------------------------------------------------------------------------------- (11) PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) 7.8% -------------------------------------------------------------------------------- (12) TYPE OF REPORTING PERSON ** PN -------------------------------------------------------------------------------- ** SEE INSTRUCTIONS BEFORE FILLING OUT! CUSIP No. 293904108 13G Page 5 of 17 Pages -------------------------------------------------------------------------------- (1) NAMES OF REPORTING PERSONS I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS Highbridge Master L.P. -------------------------------------------------------------------------------- (2) CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP ** (a) [X] (b) [ ] -------------------------------------------------------------------------------- (3) SEC USE ONLY -------------------------------------------------------------------------------- (4) CITIZENSHIP OR PLACE OF ORGANIZATION Cayman Islands, British West Indies -------------------------------------------------------------------------------- NUMBER OF (5) SOLE VOTING POWER 0 SHARES _________________________________________________________________ BENEFICIALLY (6) SHARED VOTING POWER 4.0% Convertible Senior Notes, due 2013, convertible into 3,455,496 shares of Common Stock 235,656 shares of Common Stock OWNED BY _________________________________________________________________ EACH (7) SOLE DISPOSITIVE POWER 0 REPORTING _________________________________________________________________ PERSON WITH (8) SHARED DISPOSITIVE POWER 4.0% Convertible Senior Notes, due 2013, convertible into 3,455,496 shares of Common Stock 235,656 shares of Common Stock -------------------------------------------------------------------------------- (9) AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 4.0% Convertible Senior Notes, due 2013, convertible into 3,455,496 shares of Common Stock 235,656 shares of Common Stock -------------------------------------------------------------------------------- (10) CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES ** [ ] -------------------------------------------------------------------------------- (11) PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) 7.8% -------------------------------------------------------------------------------- (12) TYPE OF REPORTING PERSON ** PN -------------------------------------------------------------------------------- ** SEE INSTRUCTIONS BEFORE FILLING OUT! CUSIP No. 293904108 13G Page 6 of 17 Pages -------------------------------------------------------------------------------- (1) NAMES OF REPORTING PERSONS I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS Highbridge GP, Ltd. -------------------------------------------------------------------------------- (2) CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP ** (a) [X] (b) [ ] -------------------------------------------------------------------------------- (3) SEC USE ONLY -------------------------------------------------------------------------------- (4) CITIZENSHIP OR PLACE OF ORGANIZATION Cayman Islands, British West Indies -------------------------------------------------------------------------------- NUMBER OF (5) SOLE VOTING POWER 0 SHARES _________________________________________________________________ BENEFICIALLY (6) SHARED VOTING POWER 4.0% Convertible Senior Notes, due 2013, convertible into 3,455,496 shares of Common Stock 235,656 shares of Common Stock OWNED BY _________________________________________________________________ EACH (7) SOLE DISPOSITIVE POWER 0 REPORTING _________________________________________________________________ PERSON WITH (8) SHARED DISPOSITIVE POWER 4.0% Convertible Senior Notes, due 2013, convertible into 3,455,496 shares of Common Stock 235,656 shares of Common Stock -------------------------------------------------------------------------------- (9) AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 4.0% Convertible Senior Notes, due 2013, convertible into 3,455,496 shares of Common Stock 235,656 shares of Common Stock -------------------------------------------------------------------------------- (10) CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES ** [ ] -------------------------------------------------------------------------------- (11) PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) 7.8% ________________________________________________________________________________ (12) TYPE OF REPORTING PERSON ** OO -------------------------------------------------------------------------------- ** SEE INSTRUCTIONS BEFORE FILLING OUT! CUSIP No. 293904108 13G Page 7 of 17 Pages -------------------------------------------------------------------------------- (1) NAMES OF REPORTING PERSONS I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS Highbridge GP, LLC -------------------------------------------------------------------------------- (2) CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP ** (a) [X] (b) [ ] -------------------------------------------------------------------------------- (3) SEC USE ONLY -------------------------------------------------------------------------------- (4) CITIZENSHIP OR PLACE OF ORGANIZATION State of Delaware -------------------------------------------------------------------------------- NUMBER OF (5) SOLE VOTING POWER 0 SHARES _________________________________________________________________ BENEFICIALLY (6) SHARED VOTING POWER 4.0% Convertible Senior Notes, due 2013, convertible into 3,455,496 shares of Common Stock 235,656 shares of Common Stock OWNED BY _________________________________________________________________ EACH (7) SOLE DISPOSITIVE POWER 0 REPORTING _________________________________________________________________ PERSON WITH (8) SHARED DISPOSITIVE POWER 4.0% Convertible Senior Notes, due 2013, convertible into 3,455,496 shares of Common Stock 235,656 shares of Common Stock -------------------------------------------------------------------------------- (9) AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 4.0% Convertible Senior Notes, due 2013, convertible into 3,455,496 shares of Common Stock 235,656 shares of Common Stock -------------------------------------------------------------------------------- (10) CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES ** [ ] -------------------------------------------------------------------------------- (11) PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) 7.8% ________________________________________________________________________________ (12) TYPE OF REPORTING PERSON ** OO -------------------------------------------------------------------------------- ** SEE INSTRUCTIONS BEFORE FILLING OUT! CUSIP No. 293904108 13G Page 8 of 17 Pages -------------------------------------------------------------------------------- (1) NAMES OF REPORTING PERSONS I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS Highbridge Capital Management, LLC 20-1901985 -------------------------------------------------------------------------------- (2) CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP ** (a) [X] (b) [ ] -------------------------------------------------------------------------------- (3) SEC USE ONLY -------------------------------------------------------------------------------- (4) CITIZENSHIP OR PLACE OF ORGANIZATION State of Delaware -------------------------------------------------------------------------------- NUMBER OF (5) SOLE VOTING POWER 0 SHARES _________________________________________________________________ BENEFICIALLY (6) SHARED VOTING POWER 4.0% Convertible Senior Notes, due 2013, convertible into 3,455,496 shares of Common Stock 235,656 shares of Common Stock OWNED BY _________________________________________________________________ EACH (7) SOLE DISPOSITIVE POWER 0 REPORTING _________________________________________________________________ PERSON WITH (8) SHARED DISPOSITIVE POWER 4.0% Convertible Senior Notes, due 2013, convertible into 3,455,496 shares of Common Stock 235,656 shares of Common Stock -------------------------------------------------------------------------------- (9) AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 4.0% Convertible Senior Notes, due 2013, convertible into 3,455,496 shares of Common Stock 235,656 shares of Common Stock -------------------------------------------------------------------------------- (10) CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES ** [ ] -------------------------------------------------------------------------------- (11) PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) 7.8% -------------------------------------------------------------------------------- (12) TYPE OF REPORTING PERSON ** OO - Limited Liability Company -------------------------------------------------------------------------------- ** SEE INSTRUCTIONS BEFORE FILLING OUT! CUSIP No. 293904108 13G Page 9 of 17 Pages -------------------------------------------------------------------------------- (1) NAMES OF REPORTING PERSONS I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS Glenn Dubin -------------------------------------------------------------------------------- (2) CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP ** (a) [X] (b) [ ] -------------------------------------------------------------------------------- (3) SEC USE ONLY -------------------------------------------------------------------------------- (4) CITIZENSHIP OR PLACE OF ORGANIZATION United States -------------------------------------------------------------------------------- NUMBER OF (5) SOLE VOTING POWER 0 SHARES _________________________________________________________________ BENEFICIALLY (6) SHARED VOTING POWER 4.0% Convertible Senior Notes, due 2013, convertible into 3,455,496 shares of Common Stock 235,656 shares of Common Stock OWNED BY _________________________________________________________________ EACH (7) SOLE DISPOSITIVE POWER 0 REPORTING _________________________________________________________________ PERSON WITH (8) SHARED DISPOSITIVE POWER 4.0% Convertible Senior Notes, due 2013, convertible into 3,455,496 shares of Common Stock 235,656 shares of Common Stock -------------------------------------------------------------------------------- (9) AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 4.0% Convertible Senior Notes, due 2013, convertible into 3,455,496 shares of Common Stock 235,656 shares of Common Stock -------------------------------------------------------------------------------- (10) CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES ** [ ] -------------------------------------------------------------------------------- (11) PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) 7.8% -------------------------------------------------------------------------------- (12) TYPE OF REPORTING PERSON ** IN -------------------------------------------------------------------------------- ** SEE INSTRUCTIONS BEFORE FILLING OUT! CUSIP No. 293904108 13G Page 10 of 17 Pages -------------------------------------------------------------------------------- (1) NAMES OF REPORTING PERSONS I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS Henry Swieca -------------------------------------------------------------------------------- (2) CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP ** (a) [X] (b) [ ] -------------------------------------------------------------------------------- (3) SEC USE ONLY -------------------------------------------------------------------------------- (4) CITIZENSHIP OR PLACE OF ORGANIZATION United States -------------------------------------------------------------------------------- NUMBER OF (5) SOLE VOTING POWER 0 SHARES _________________________________________________________________ BENEFICIALLY (6) SHARED VOTING POWER 4.0% Convertible Senior Notes, due 2013, convertible into 3,455,496 shares of Common Stock 235,656 shares of Common Stock OWNED BY _________________________________________________________________ EACH (7) SOLE DISPOSITIVE POWER 0 REPORTING _________________________________________________________________ PERSON WITH (8) SHARED DISPOSITIVE POWER 4.0% Convertible Senior Notes, due 2013, convertible into 3,455,496 shares of Common Stock 235,656 shares of Common Stock -------------------------------------------------------------------------------- (9) AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 4.0% Convertible Senior Notes, due 2013, convertible into 3,455,496 shares of Common Stock 235,656 shares of Common Stock -------------------------------------------------------------------------------- (10) CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES ** [ ] -------------------------------------------------------------------------------- (11) PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) 7.8% -------------------------------------------------------------------------------- (12) TYPE OF REPORTING PERSON ** IN -------------------------------------------------------------------------------- ** SEE INSTRUCTIONS BEFORE FILLING OUT! CUSIP No. 293904108 13G Page 11 of 17 Pages Item 1. (a) Name of Issuer Enzon Pharmaceuticals, Inc. (the "Company"). (b) Address of Issuer's Principal Executive Offices 685 Route 202/206 Bridgewater, New Jersey 08807 Item 2(a). Name of Person Filing Item 2(b). Address of Principal Business Office Item 2(c). Citizenship HIGHBRIDGE INTERNATIONAL LLC c/o Harmonic Fund Services The Cayman Corporate Centre, 4th Floor 27 Hospital Road Grand Cayman, Cayman Islands, British West Indies Citizenship: Cayman Islands, British West Indies HIGHBRIDGE CAPITAL CORPORATION c/o Harmonic Fund Services The Cayman Corporate Centre, 4th Floor 27 Hospital Road Grand Cayman, Cayman Islands, British West Indies Citizenship: Cayman Islands, British West Indies HIGHBRIDGE MASTER L.P. c/o Harmonic Fund Services The Cayman Corporate Centre, 4th Floor 27 Hospital Road Grand Cayman, Cayman Islands, British West Indies Citizenship: Cayman Islands, British West Indies HIGHBRIDGE CAPITAL L.P. c/o Highbridge Capital Management, LLC 9 West 57th Street, 27th Floor New York, New York 10019 Citizenship: State of Delaware HIGHBRIDGE GP, LTD. c/o Harmonic Fund Services The Cayman Corporate Centre, 4th Floor 27 Hospital Road Grand Cayman, Cayman Islands, British West Indies Citizenship: Cayman Islands, British West Indies HIGHBRIDGE GP, LLC c/o Highbridge Capital Management, LLC 9 West 57th Street, 27th Floor New York, New York 10019 Citizenship: State of Delaware HIGHBRIDGE CAPITAL MANAGEMENT, LLC IRS #: 20-1901985 CUSIP No. 293904108 13G Page 12 of 17 Pages 9 West 57th Street, 27th Floor New York, New York 10019 Citizenship: State of Delaware GLENN DUBIN c/o Highbridge Capital Management, LLC 9 West 57th Street, 27th Floor New York, New York 10019 Citizenship: United States HENRY SWIECA c/o Highbridge Capital Management, LLC 9 West 57th Street, 27th Floor New York, New York 10019 Citizenship: United States Item 2(d) Title of Class of Securities Common Stock, $0.01 par value ("Common Stock") Item 2(e) CUSIP Number 293904108 Item 3. If this statement is filed pursuant to Rules 13d-1(b), or 13d-2(b) or (c), check whether the person filing is a: (a) [ ] Broker or dealer registered under Section 15 of the Act (15 U.S.C. 78o). (b) [ ] Bank as defined in Section 3(a)(6) of the Act (15 U.S.C. 78c). (c) [ ] Insurance company as defined in Section 3(a)(19) of the Act (15 U.S.C. 78c). (d) [ ] Investment company registered under Section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8). (e) [ ] An investment adviser in accordance with Rule 13d-1(b)(1)(ii)(E); (f) [ ] An employee benefit plan or endowment fund in accordance with Rule 13d-1(b)(1)(ii)(F); (g) [ ] A parent holding company or control person in accordance with Rule 13d-1(b)(1)(ii)(G); (h) [ ] A savings association as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813); (i) [ ] A church plan that is excluded from the definition of an investment company under Section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3); (j) [ ] Group, in accordance with Rule 13d-1(b)(1)(ii)(J). If this statement is filed pursuant to Rule 13d-1(c), check this box. [X] CUSIP No. 293904108 13G Page 13 of 17 Pages Item 4. Ownership Provide the following information regarding the aggregate number and percentage of the class of securities of the issuer identified in Item 1. (a) Amount beneficially owned: As of the date of this filing, each Reporting Person may be deemed the beneficial owner of (i) 4.0% Convertible Senior Notes due 2013 convertible into 3,455,496 shares of Common Stock issuable to Highbridge International LLC and (ii) 235,656 shares of stock issued to Highbridge International LLC. Highbridge International LLC is a subsidiary of Highbridge Master L.P. Highbridge Capital Corporation and Highbridge Capital L.P. are limited partners of Highbridge Master L.P. Highbridge GP, Ltd. is the General Partner of Highbridge Master L.P. Highbridge GP, LLC is the General Partner of Highbridge Capital L.P. Highbridge Capital Management, LLC is the trading manager of Highbridge Capital Corporation, Highbridge Capital L.P. and Highbridge Master L.P. Glenn Dubin is a Co-Chief Executive Officer of Highbridge Capital Management, LLC. Henry Swieca is a Co-Chief Executive Officer of Highbridge Capital Management, LLC. The foregoing should not be construed in and of itself as an admission by any Reporting Person as to beneficial ownership of shares of Common Stock owned by another Reporting Person. In addition, each of Highbridge Master L.P., Highbridge Capital Corporation, Highbridge Capital L.P., Highbridge GP, Ltd., Highbridge GP, LLC, Highbridge Capital Management, LLC, Glenn Dubin and Henry Swieca disclaims beneficial ownership of shares of Common Stock owned by Highbridge International LLC. (b) Percent of class: The Company's quarterly report on Form 10-Q that was filed on May 3, 2006, indicates there were 43,761,855 shares of Common Stock outstanding as of May 1, 2006. Therefore, based on the Company's outstanding shares of Common Stock and the Common Stock issuable upon the conversion of the 4.0% Convertible Senior Notes due 2013, issued by the Company, the Reporting Persons may be deemed to beneficially own approximately 7.8% of the outstanding shares of Common Stock of the Company. The foregoing should not be construed in and of itself as an admission by any Reporting Person as to beneficial ownership of shares of Common Stock owned by another Reporting Person. (c) Number of shares as to which such person has: (i) Sole power to vote or to direct the vote 0 (ii) Shared power to vote or to direct the vote See Item 4(a) (iii) Sole power to dispose or to direct the disposition of 0 CUSIP No. 293904108 13G Page 14 of 17 Pages (iv) Shared power to dispose or to direct the disposition of See Item 4(a) Item 5. Ownership of Five Percent or Less of a Class Not applicable. Item 6. Ownership of More than Five Percent on Behalf of Another Person Not applicable. Item 7. Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person Not applicable. Item 8. Identification and Classification of Members of the Group See Exhibit I. Item 9. Notice of Dissolution of Group Not applicable. Item 10. Certification By signing below each of the undersigned certifies that, to the best of its knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect. Exhibits: Exhibit I: Joint Filing Agreement, dated as of May 26, 2006, by and among Highbridge International LLC, Highbridge Capital Corporation, Highbridge Capital L.P., Highbridge Master L.P., Highbridge GP, Ltd., Highbridge GP, LLC, Highbridge Capital Management, LLC, Glenn Dubin and Henry Swieca. CUSIP No. 293904108 13G Page 15 of 17 Pages SIGNATURES After reasonable inquiry and to the best of its knowledge and belief, each of the undersigned certifies that the information with respect to it set forth in this statement is true, complete, and correct. Dated: May 26, 2006 HIGHBRIDGE INTERNATIONAL LLC HIGHBRIDGE CAPITAL L.P. By: Highbridge GP, LLC By: /s/ Howard Feitelberg its General Partner -------------------------- Name: Howard Feitelberg Title: Director By: /s/ Clive Harris -------------------------- Name: Clive Harris Title: Director HIGHBRIDGE CAPITAL CORPORATION HIGHBRIDGE GP, LTD. By: /s/ Clive Harris -------------------------- Name: Clive Harris Title: Director By: /s/ Clive Harris -------------------------- Name: Clive Harris Title: Director HIGHBRIDGE MASTER L.P. HIGHBRIDGE CAPITAL MANAGEMENT, LLC By: Highbridge GP, Ltd. its General Partner By: /s/ Carolyn Rubin -------------------------- Name: Carolyn Rubin Title: Deputy General Counsel By: /s/ Clive Harris -------------------------- Name: Clive Harris Title: Director HIGHBRIDGE GP, LLC By: /s/ Clive Harris /s/ Henry Swieca -------------------------- -------------------------- Name: Clive Harris Title: Director HENRY SWIECA /s/ Glenn Dubin -------------------------- GLENN DUBIN CUSIP No. 293904108 13G Page 16 of 17 Pages EXHIBIT I JOINT FILING AGREEMENT This will confirm the agreement by and among the undersigned that the Schedule 13G filed with the Securities and Exchange Commission on or about the date hereof with respect to the beneficial ownership by the undersigned of the Common Stock, $0.01 par value, of Enzon Pharmaceuticals, Inc., is being filed, and all amendments thereto will be filed, on behalf of each of the persons and entities named below in accordance with Rule 13d-1(k) under the Securities Exchange Act of 1934, as amended. This Agreement may be executed in two or more counterparts, each of which shall be deemed an original, but all of which together shall constitute one and the same instrument. Dated as of May 26, 2006 HIGHBRIDGE INTERNATIONAL LLC HIGHBRIDGE CAPITAL L.P. By: Highbridge GP, LLC By: /s/ Howard Feitelberg its General Partner -------------------------- Name: Howard Feitelberg Title: Director By: /s/ Clive Harris -------------------------- Name: Clive Harris Title: Director HIGHBRIDGE CAPITAL CORPORATION HIGHBRIDGE GP, LTD. By: /s/ Clive Harris -------------------------- Name: Clive Harris Title: Director By: /s/ Clive Harris -------------------------- Name: Clive Harris Title: Director HIGHBRIDGE MASTER L.P. HIGHBRIDGE CAPITAL MANAGEMENT, LLC By: Highbridge GP, Ltd. its General Partner By: /s/ Carolyn Rubin -------------------------- Name: Carolyn Rubin Title: Deputy General Counsel By: /s/ Clive Harris -------------------------- Name: Clive Harris Title: Director HIGHBRIDGE GP, LLC By: /s/ Clive Harris /s/ Henry Swieca -------------------------- -------------------------- Name: Clive Harris Title: Director HENRY SWIECA CUSIP No. 293904108 13G Page 17 of 17 Pages /s/ Glenn Dubin -------------------------- GLENN DUBIN