------------------------------ OMB APPROVAL ------------------------------ OMB Number: 3235-0362 Expires: September 30, 1998 Estimated average burden hours per response . . . . 1.0 ------------------------------ U.S. SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 5 ANNUAL STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(f) of the Investment Company Act of 1940 |X| Check this box if no longer subject of Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b). |_| Form 3 Holdings Reported |_| Form 4 Transactions Reported ================================================================================ 1. Name and Address of Reporting Person* Thurman Randy H. -------------------------------------------------------------------------------- (Last) (First) (Middle) c/o Enzon, Inc., 685 Route 202/206 -------------------------------------------------------------------------------- (Street) Bridgewater New Jersey 08807 -------------------------------------------------------------------------------- (City) (State) (Zip) ================================================================================ 2. Issuer Name and Ticker or Trading Symbol ENZON, INC. (ENZN) ================================================================================ 3. IRS Identification Number of Reporting Person, if an Entity (Voluntary) ================================================================================ 4. Statement for Month/Year June 30, 2002 ================================================================================ 5. If Amendment, Date of Original (Month/Year) ================================================================================ 6. Relationship of Reporting Person to Issuer (Check all applicable) |_| Director |_| 10% Owner |_| Officer (give title below) |X| Other (specify below) Former Director ================================================================================ 7. Individual or Joint/Group Filing (Check Applicable Line) |X| Form filed by One Reporting Person |_| Form filed by More than One Reporting Person ================================================================================ * If the Form is filed by more than one Reporting Person, see Instruction 4(b)(v). ================================================================================ Table I -- Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned ================================================================================

1) Securities granted by Enzon, Inc. pursuant to the Independent Directors' Stock Plan as compensation for service as a member of the Board of Directors of Enzon, Inc. during the year ended December 31, 2001 and qualified under Rule 16b-3(d). The value of the compensation was $14,500. * If the form is filed by more than one reporting person, see Instruction 4(b)(v). FORM 5 (continued) Table II -- Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities) ================================================================================

Explanation of Responses: (a) Acquired pursuant to the Company's Non-Qualified Stock Option Plan and qualified under Rule 16b-3. (b) The Options were cancelled on May 7, 2002 as a result of Reporting Person's resignation from the Company's Board of Directors. --------------------------------------------- ----------------------- **Signature of Reporting Person Date ** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a). Note: File three copies of this Form, one of which must be manually signed. If space provided is insufficient, see Instruction 6 for procedure. Potential persons who are to respond to the collections of information contained in this form are not required to respond unless the form displays a currently valid OMB number. Page 2

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