# EDGAR Filing Document

**Accession Number:** 0000727510
**File Stem:** 0001104659-26-033624
**Filing Date:** 2026-3
**Character Count:** 39410
**Document Hash:** b5581fa03b2e835e0af2bcd74f40cc0a
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001104659-26-033624.hdr.sgml**: 20260324

**ACCESSION NUMBER**: 0001104659-26-033624

**CONFORMED SUBMISSION TYPE**: 8-K

**PUBLIC DOCUMENT COUNT**: 15

**CONFORMED PERIOD OF REPORT**: 20260320

**ITEM INFORMATION**: Entry into a Material Definitive Agreement

**ITEM INFORMATION**: Material Modifications to Rights of Security Holders

**ITEM INFORMATION**: Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year

**ITEM INFORMATION**: Regulation FD Disclosure

**ITEM INFORMATION**: Financial Statements and Exhibits

**FILED AS OF DATE**: 20260324

**DATE AS OF CHANGE**: 20260324

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** ENZON PHARMACEUTICALS, INC.
- **CENTRAL INDEX KEY:** 0000727510
- **STANDARD INDUSTRIAL CLASSIFICATION:** BIOLOGICAL PRODUCTS (NO DIAGNOSTIC SUBSTANCES) [2836]
- **ORGANIZATION NAME:** 03 Life Sciences
- **EIN:** 222372868
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** 8-K
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 000-12957
- **FILM NUMBER:** 26784271

**BUSINESS ADDRESS:**
- **STREET 1:** 20 COMMERCE DRIVE, SUITE 135
- **CITY:** CRANFORD
- **STATE:** NJ
- **ZIP:** 07016
- **BUSINESS PHONE:** 732-980-4500

**MAIL ADDRESS:**
- **STREET 1:** 20 COMMERCE DRIVE, SUITE 135
- **CITY:** CRANFORD
- **STATE:** NJ
- **ZIP:** 07016

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** ENZON PHARMACEUTICALS INC
- **DATE OF NAME CHANGE:** 20060324

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** ENZON PHARMACEUTICALS  INC
- **DATE OF NAME CHANGE:** 20021211

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** ENZON PHARMACEUTICAL  INC
- **DATE OF NAME CHANGE:** 20021210

?xml version='1.0' encoding='ASCII'?

**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): **March 20, 2026**

**ENZON PHARMACEUTICALS, INC.**

(Exact name of registrant as specified in its charter)

---

| | | |
|:---|:---|:---|
| **Delaware**<br> (State or other jurisdiction<br> of incorporation) | **000-12957**<br> (Commission File Number) | **22-2372868**<br> (IRS Employer Identification No.) |

---

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| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **20 Commerce Drive (Suite 135), Cranford, New Jersey**<br> (Address of principal executive offices) | **07016**<br> (Zip Code) |

---

**(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:

⌧ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

◻ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

◻ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

◻ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

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| | | |
|:---|:---|:---|
| **Title of each class** | **Trading Symbol(s)** | **Name of each exchange on which registered** |
| None | N/A | N/A |

---

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. ◻

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| | |
|:---|:---|
| **Item 1.01** | **Entry into a Material Definitive Agreement.** |

---

On March 23, 2026, Enzon Pharmaceuticals, Inc. (the "***Company***") entered into the Eleventh Amendment to the Section 382 Rights Agreement (the "***Eleventh Amendment***"), which amends the Section 382 Rights Agreement, dated as of August 14, 2020 (the "***Rights Agreement***"), by and between the Company and Continental Stock Transfer & Trust Company, as rights agent. Effective as of June 2, 2021, the Company amended the Rights Agreement (the "***First Amendment***") to extend the Final Expiration Date (as defined in the Rights Agreement) of the rights issued pursuant to the Rights Agreement from the close of business on August 13, 2021 to the close of business on June 2, 2024. Effective as of May 16, 2024, the Company amended the Rights Agreement (the "***Second Amendment***") to extend the Final Expiration Date of the rights issued pursuant to the Rights Agreement from the close of business on June 2, 2024 to the close of business on March 31, 2025. Effective as of March 31, 2025, the Company entered into the Third Amendment (the "***Third Amendment***") to extend the Final Expiration Date of the rights issued pursuant to the Rights Agreement from the close of business on March 31, 2025 to the close of business on June 30, 2026. On August 13, 2025, the Company entered into the Fourth Amendment (the "***Fourth Amendment***"), to amend the Final Expiration Date of the rights issued pursuant to the Rights Agreement from the close of business on June 30, 2026 to the close of business on September 30, 2025. On September 30, 2025, the Company entered into the Fifth Amendment (the "***Fifth Amendment***") to amend the Final Expiration Date of the rights issued pursuant to the Rights Agreement from the close of business on September 30, 2025 to the close of business on December 31, 2025. On December 23, 2025, the Company entered into the Sixth Amendment (the "***Sixth Amendment***") to amend the Final Expiration Date of the rights issued pursuant to the Rights Agreement from the close of business on December 31, 2025 to the close of business on January 31, 2026. On January 30, 2026, the Company entered into the Seventh Amendment (the "***Seventh Amendment***") to amend the Final Expiration Date of the rights issued pursuant to the Rights Agreement from the close of business on January 31, 2026 to noon, New York City time, on March 2, 2026. On February 27, 2026, the Company entered into the Eighth Amendment (the "***Eighth Amendment***") to amend the Final Expiration Date of the rights issued pursuant to the Rights Agreement from noon, New York City time, on March 2, 2026 to noon, New York City time, on March 11, 2026. On March 10, 2026, the Company entered into the Ninth Amendment (the "***Ninth Amendment***") to amend the Final Expiration Date of the rights issued pursuant to the Rights Agreement from noon, New York City time, on March 11, 2026 to noon, New York City time, on March 18, 2026. On March 18, 2026, the Company entered into the Tenth Amendment (the "***Tenth Amendment***") to amend the Final Expiration Date of the rights issued pursuant to the Rights Agreement from noon, New York City time, on March 18, 2026 to noon, New York City time, on March 24, 2026.

On March 23, 2026, the Company entered into the Eleventh Amendment to amend the Final Expiration Date of the rights issued pursuant to the Rights Agreement from noon, New York City time, on March 24, 2026, to noon, New York City time, on March 26, 2026. Except for the adjustment to the Final Expiration Date, the Rights Agreement otherwise remains unmodified.

The Eleventh Amendment has been adopted because the Company's management believes that it is in the best interests of the Company and its stockholders to provide for a Final Expiration Date of noon, New York City time, on March 26, 2026, as established in the Eleventh Amendment.

The foregoing description does not purport to be complete and is qualified in its entirety by reference to the complete text of (i) the Rights Agreement, which was filed with the U.S. Securities and Exchange Commission (the "***SEC***") as Exhibit 4.1 to the Company's Registration Statement on Form 8-A filed with the SEC on August 14, 2020, (ii) the First Amendment, which was filed with the SEC as Exhibit 4.1 to the Company's Current Report on Form 8-K filed on June 8, 2021, (iii) the Second Amendment, which was filed with the SEC as Exhibit 4.1 to the Company's Current Report on Form 8-K filed on May 22, 2024, (iv) the Third Amendment, which was filed with the SEC as Exhibit 4.1 to the Company's Current Report on Form 8-K filed on April 1, 2025, (v) the Fourth Amendment, which was filed with the SEC as Exhibit 4.1 to the Company's Quarterly Report on Form 10-Q filed on August 14, 2025, (vi) the Fifth Amendment, which was filed with the SEC as Exhibit 4.1 to the Company's Current Report on Form 8-K on September 30, 2025, (vii) the Sixth Amendment, which was filed with the SEC as Exhibit 4.1 to the Company's Current Report on Form 8-K on December 23, 2025, (viii) the Seventh Amendment, which was filed with the SEC as Exhibit 4.1 to the Company's Current Report on Form 8-K on January 30, 2026, (ix) the Eighth Amendment, which was filed with the SEC as Exhibit 4.1 to the Company's Current Report on Form 8-K on February 27, 2026, (x) the Ninth Amendment, which was filed with the SEC as Exhibit 4.1 to the Company's Current Report on Form 8-K on March 11, 2026, (xi) the Tenth Amendment, which was filed with the SEC as Exhibit 4.1 to the Company's Current Report on Form 8-K on March 18, 2026, and (xii) the Eleventh Amendment, which is attached hereto as Exhibit 4.1. The Rights Agreement, the First Amendment, the Second Amendment, the Third Amendment, the Fourth Amendment, the Fifth Amendment, the Sixth Amendment, the Seventh Amendment, the Eighth Amendment, the Ninth Amendment, the Tenth Amendment and the Eleventh Amendment are incorporated herein by reference.

---

| | |
|:---|:---|
| **Item 3.03** | **Material Modifications to Rights of Security Holders.** |

---

The information set forth in Item 1.01 of this Current Report on Form 8-K is incorporated by reference into this Item 3.03. To the extent required by Item 3.03, the disclosure set forth in Item 5.03 is incorporated herein by reference.

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| | |
|:---|:---|
| **Item 5.03** | **Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year.** |

---

On March 24, 2026, the Company announced that the 1-for-100 reverse stock split (the "<u>Reverse Stock Split</u>"), which was previously approved by the Company's stockholders, will become effective as of 4:30 p.m., Eastern Time, on March 24, 2026 ("<u>Effective Time</u>"). The Company's common stock, $0.01 par value per share (the "<u>Common Stock</u>"), is expected to begin trading on a reverse stock split-adjusted basis on the OTCQB at market open on March 25, 2026. The Common Stock is expected to trade under the temporary symbol "ENZND" for 20 trading days. As of the Effective Time, every one hundred (100) shares of the Company's issued and outstanding shares of Common Stock will be combined into one (1) share of Common Stock. The par value per share of the Common Stock will not change. No fractional shares will be issued in connection with the Reverse Stock Split, and stockholders who would otherwise be entitled to a fractional share will receive a proportional cash payment. The Reverse Stock Split is required to be completed prior to the completion of the merger that is contemplated between Enzon's wholly owned subsidiary and Viskase Companies, Inc. A copy of the Certificate of Amendment to the Amended and Restated Certificate of Incorporation that was filed with the Secretary of State of the State of Delaware on March 23, 2026 is attached as <u>Exhibit 3.1</u> hereto and is incorporated herein by reference. The Certificate of Amendment amends the Effective Time of the Reverse Stock Split set forth in a Certificate of Amendment which was filed with the Secretary of State of the State of Delaware on March 20, 2026, which is attached hereto as <u>Exhibit 3.2</u>.

---

| | |
|:---|:---|
| **Item 7.01** | **Regulation FD Disclosure.** |

---

On March 24, 2026, Enzon issued a press release relating to the Reverse Stock Split. A copy of the press release is attached as <u>Exhibit 99.1</u> hereto and incorporated herein by reference.

In accordance with General Instruction B.2 of Form 8-K, the foregoing information, including Exhibit 99.1, shall not be deemed "filed" for the purposes of Section 18 of the Exchange Act of 1934, as amended (the "<u>Exchange Act</u>"), or otherwise subject to the liabilities of that section, nor shall such information, including Exhibit 99.1, be deemed incorporated by reference into any filing under the Securities Act or the Exchange Act, except as shall be expressly set forth by specific reference in such filing.

---

| | |
|:---|:---|
| **Item 9.01** | **Financial Statements and Exhibits.** |

---

(d) Exhibits.

---

| | |
|:---|:---|
| **Exhibit** | **Description** |
| [3.1\*](tm267492d15_ex3-1.htm) | [Certificate of Amendment to the Amended and Restated Certificate of Incorporation of Enzon Pharmaceuticals, Inc., dated March 24, 2026.](tm267492d15_ex3-1.htm) |
| [3.2\*](tm267492d15_ex3-2.htm) | [Certificate of Amendment to the Amended and Restated Certificate of Incorporation of Enzon Pharmaceuticals, Inc., dated March 20, 2026.](tm267492d15_ex3-2.htm) |
| [4.1\*](tm267492d15_ex4-1.htm) | [Eleventh Amendment to the Section 382 Rights Agreement, dated as of March 23, 2026, by and between Enzon Pharmaceuticals, Inc. and Continental Stock Transfer & Trust Company.](tm267492d15_ex4-1.htm) |
| [99.1](tm267492d15_ex99-1.htm) | [Press Release issued by Enzon Pharmaceuticals, Inc., dated March 24, 2026.](tm267492d15_ex99-1.htm) |
| 104 | Cover Page Interactive Data File (embedded within the Inline XBRL document). |

---

\* Filed herewith.

**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.

---

| | | |
|:---|:---|:---|
|  | **ENZON PHARMACEUTICALS, INC.** | **ENZON PHARMACEUTICALS, INC.** |
|  | (Registrant) | (Registrant) |
| Date: March 24, 2026 |  |  |
|  | By: | /s/ Richard L. Feinstein |
|  | Name: | Richard L. Feinstein |
|  | Title: | Chief Executive Officer, Chief Financial Officer and Secretary |

---

## Exhibit 3.1

**Exhibit 3.1**

**CERTIFICATE OF AMENDMENT TO THE**

**AMENDED AND RESTATED CERTIFICATE OF INCORPORATION**

**OF**

**Enzon Pharmaceuticals, Inc.**

(Pursuant to Section 242 of the General Corporation Law of the State of Delaware)

**ENZON PHARMACEUTICALS, INC.** (the *"**Corporation**"*), a corporation organized and existing under and by virtue of the General Corporation Law of the State of Delaware (the *"**DGCL**"*), does hereby certify that:

**FIRST:** The present name of the Corporation is Enzon Pharmaceuticals, Inc.

**SECOND:** The name under which the corporation was originally incorporated is Enzon, Inc. and the date of the filing of the original certificate of incorporation of the Corporation with the Secretary of State of the State of Delaware is May 11, 1983 (as so amended, the "***Certificate of Incorporation***").

**THIRD:** The Certificate of Incorporation is hereby amended by amending and restating clause (C) of Section 4 of ARTICLE FOURTH in its entirety as follows:

"(C) Effective March 24, 2026 at 4:30 p.m. (the "***Effective Time***"), each one hundred (100) shares of the Corporation's Common Stock that are issued and outstanding immediately prior to the Effective Time shall, automatically and without any action on the part of the Corporation or respective holders thereof, be reclassified and combined into one (1) share of Common Stock (the "***Reverse Split***"). If, upon aggregating all of the shares of Common Stock held by a holder of Common Stock immediately following the Reverse Split such holder would otherwise be entitled to a fractional share of Common Stock, the Corporation shall pay in cash (without interest) to each such holder an amount equal to such fraction multiplied by the closing price of the Common Stock on the OTCQB, or such other market or exchange as such shares of Common Stock may then be traded, on the last trading day immediately preceding the Effective Time (with such closing price proportionately adjusted to give effect to the Reverse Split).

Each stock certificate that, immediately prior to the Effective Time, represented shares of Common Stock that were issued and outstanding immediately prior to the Effective Time, shall, from and after the Effective Time, automatically and without the necessity of presenting the same for exchange, represent that number of whole shares of Common Stock after the Effective Time into which the shares formerly represented by such certificate have been reclassified, as well as the right to receive cash in lieu of fractional shares of Common Stock to which such holder may be entitled; *provided*, *however*, that each person of record holding a certificate that represented shares of Common Stock that were issued and outstanding immediately prior to the Effective Time shall receive, upon surrender of such certificate, a new certificate evidencing and representing the number of whole shares of Common Stock after the Effective Time into which the shares of Common Stock formerly represented by such certificate shall have been reclassified, as well as the right to receive cash in lieu of fractional shares of Common Stock to which such holder may be entitled."

**FOURTH:** Resolutions were duly adopted by the Board of Directors of the Corporation setting forth this proposed Certificate of Amendment to the Certificate of Incorporation and declaring said amendment to be advisable and calling for the consideration and approval thereof at a meeting of the stockholders of the Corporation. Pursuant to the resolution of the Board of Directors, a meeting of the stockholders of the Company was duly called and held upon notice in accordance with Section 222 of the General Corporation Law of the State of Delaware at which meeting the necessary number of shares as required by statute were voted in favor of the foregoing amendment.

**FIFTH:** The foregoing amendment was duly adopted in accordance with the provisions of Section 242 of the General Corporation Law of the State of Delaware.

**SIXTH:** That this Certificate of Amendment shall become effective upon filing with the Secretary of State.

**In Witness Whereof**, Enzon Pharmaceuticals, Inc. has caused this Certificate of Amendment to be executed by its duly authorized officer on this 23rd day of March, 2026.

---

| | |
|:---|:---|
| **Enzon Pharmaceuticals, Inc.** | **Enzon Pharmaceuticals, Inc.** |
| By: | /s/ Richard L. Feinstein |
| Name: Richard L. Feinstein | Name: Richard L. Feinstein |
| Title: Chief Executive Officer,<br> Chief Financial Officer and Secretary | Title: Chief Executive Officer,<br> Chief Financial Officer and Secretary |

---

## Exhibit 3.2

**Exhibit 3.2**

**CERTIFICATE OF AMENDMENT TO THE**

**AMENDED AND RESTATED CERTIFICATE OF INCORPORATION**

**OF**

**Enzon Pharmaceuticals, Inc.**

(Pursuant to Section 242 of the General Corporation Law of the State of Delaware)

**ENZON PHARMACEUTICALS, INC.** (the *"**Corporation**"*), a corporation organized and existing under and by virtue of the General Corporation Law of the State of Delaware (the *"**DGCL**"*), does hereby certify that:

**FIRST:** The present name of the Corporation is Enzon Pharmaceuticals, Inc.

**SECOND:** The name under which the corporation was originally incorporated is Enzon, Inc. and the date of the filing of the original certificate of incorporation of the Corporation with the Secretary of State of the State of Delaware is May 11, 1983 (as so amended, the "***Certificate of Incorporation***").

**THIRD:** The Certificate of Incorporation is hereby amended by adding the following as a new clause (C) to Section 4 of ARTICLE FOURTH:

"(C) Effective March 23, 2026 at 5:00 p.m. (the "***Effective Time***"), each one hundred (100) shares of the Corporation's Common Stock that are issued and outstanding immediately prior to the Effective Time shall, automatically and without any action on the part of the Corporation or respective holders thereof, be reclassified and combined into one (1) share of Common Stock (the "***Reverse Split***"). If, upon aggregating all of the shares of Common Stock held by a holder of Common Stock immediately following the Reverse Split such holder would otherwise be entitled to a fractional share of Common Stock, the Corporation shall pay in cash (without interest) to each such holder an amount equal to such fraction multiplied by the closing price of the Common Stock on the OTCQB, or such other market or exchange as such shares of Common Stock may then be traded, on the last trading day immediately preceding the Effective Time (with such closing price proportionately adjusted to give effect to the Reverse Split).

Each stock certificate that, immediately prior to the Effective Time, represented shares of Common Stock that were issued and outstanding immediately prior to the Effective Time, shall, from and after the Effective Time, automatically and without the necessity of presenting the same for exchange, represent that number of whole shares of Common Stock after the Effective Time into which the shares formerly represented by such certificate have been reclassified, as well as the right to receive cash in lieu of fractional shares of Common Stock to which such holder may be entitled; *provided*, *however*, that each person of record holding a certificate that represented shares of Common Stock that were issued and outstanding immediately prior to the Effective Time shall receive, upon surrender of such certificate, a new certificate evidencing and representing the number of whole shares of Common Stock after the Effective Time into which the shares of Common Stock formerly represented by such certificate shall have been reclassified, as well as the right to receive cash in lieu of fractional shares of Common Stock to which such holder may be entitled."

**FOURTH:** Resolutions were duly adopted by the Board of Directors of the Corporation setting forth this proposed Certificate of Amendment to the Certificate of Incorporation and declaring said amendment to be advisable and calling for the consideration and approval thereof at a meeting of the stockholders of the Corporation. Pursuant to the resolution of the Board of Directors, a meeting of the stockholders of the Company was duly called and held upon notice in accordance with Section 222 of the General Corporation Law of the State of Delaware at which meeting the necessary number of shares as required by statute were voted in favor of the foregoing amendment.

**FIFTH:** The foregoing amendment was duly adopted in accordance with the provisions of Section 242 of the General Corporation Law of the State of Delaware.

**SIXTH:** That this Certificate of Amendment shall become effective upon filing with the Secretary of State.

**In Witness Whereof**, Enzon Pharmaceuticals, Inc. has caused this Certificate of Amendment to be executed by its duly authorized officer on this 20th day of March, 2026.

---

| | |
|:---|:---|
| **Enzon Pharmaceuticals, Inc.** | **Enzon Pharmaceuticals, Inc.** |
| By: | /s/ Richard L. Feinstein |
| Name: Richard L. Feinstein | Name: Richard L. Feinstein |
| Title: Chief Executive Officer,<br> Chief Financial Officer and Secretary | Title: Chief Executive Officer,<br> Chief Financial Officer and Secretary |

---

## Exhibit 4.1

**<u>EXHIBIT 4.1</u>**

**ELEVENTH AMENDMENT TO THE**

**SECTION 382 RIGHTS AGREEMENT**

**by and between**

**ENZON PHARMACEUTICALS, INC.**

**and**

**CONTINENTAL STOCK TRANSFER & TRUST COMPANY, as Rights Agent**

This **ELEVENTH AMENDMENT TO THE SECTION 382 RIGHTS AGREEMENT** (this "<u>Eleventh Amendment</u>") is made and entered into March 23, 2026, and is effective immediately, by and between Enzon Pharmaceuticals, Inc., a Delaware corporation (the "<u>Company</u>"), and Continental Stock Transfer & Trust Company, a New York corporation, as rights agent (the "<u>Rights Agent</u>").

**WHEREAS**, the Company and the Rights Agent are parties to that certain Section 382 Rights Agreement, dated as of August 14, 2020 (the "<u>Rights Agreement</u>"), as initially amended on June 4, 2021, further amended on May 16, 2024, further amended on March 31, 2025, further amended on August 13, 2025, further amended on September 30, 2025, further amended on December 23, 2025, further amended on January 30, 2026, further amended on February 27, 2026, further amended on March 10, 2026, and further amended on March 18, 2026 (the "<u>Tenth Amendment</u>");

**WHEREAS**, the Rights Agreement, under the terms of the Tenth Amendment, will expire at noon, New York City time, on March 24, 2026;

**WHEREAS**, the Company may amend the Rights Agreement pursuant to Section 26 thereof; and

**WHEREAS**, the Board of Directors of the Company has determined that it is in the best interests of the Company and its stockholders to extend the Final Expiration Date to noon, New York City Time, on March 26, 2026, in accordance with the terms set forth in this Eleventh Amendment.

**NOW, THEREFORE**, in consideration of the foregoing and other good and valuable consideration, the receipt and sufficiency of which the parties hereby acknowledge, the Company and the Rights Agent agree as follows:

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;1. **<u>Amendments</u>**.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(a) Section 7(a) of the Rights Agreement is hereby amended and restated to read as follows:

"Subject to Section 7(e) and Section 27 hereof, the registered holder of any Rights Certificate may exercise the Rights evidenced thereby (except as otherwise provided herein including, without limitation, the restrictions on exercisability set forth in Section 9(c), Section 11(a)(iii) and Section 23(a) hereof) in whole or in part at any time after the Distribution Date upon surrender of the Rights Certificate, with the form of election to purchase and the certificate on the reverse side thereof duly executed, to the Rights Agent at the principal office or offices of the Rights Agent designated for such purpose, together with payment of the aggregate Purchase Price with respect to the total number of one one-thousandth of a share of Preferred Stock (or other securities, cash or other assets, as the case may be) as to which such surrendered Rights are then exercisable, at or prior to the earliest of (i) noon, New York City time, on March 26, 2026 (the "<u>Final Expiration Date</u>"), (ii) the time at which the Rights are redeemed as provided in Section 23 hereof, (iii) the time at which all of the Rights (other than Rights that have become void pursuant to the provisions of Section 7(e) hereof) are exchanged for Common Stock or other assets or securities as provided in Section 27 hereof, (iv) the Close of Business on the effective date of the repeal of Section 382 of the Code or any successor statute if the Board of Directors determines that this Agreement is no longer necessary or desirable for the preservation of Tax Benefits, or (v) the Close of Business on the first day of a taxable year of the Company to which the Board of Directors determines that no Tax Benefits may be carried forward (the earliest of (i) and (ii) and (iii) and (iv) and (v) being herein referred to as the "<u>Expiration Date</u>").

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(b) All references to "noon, New York City time, on March 24, 2026" and
 "March 24, 2026" in <u>Exhibit B</u> (Form of Rights Certificate) and <u>Exhibit C</u> (Summary of Rights to
Purchase Series A-1 Junior Participating Preferred Stock) to the Rights Agreement are amended to replace each such reference with
 "noon, New York City time, on March 26, 2026" and "March 26, 2026", respectively.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;2. **<u>Capitalized Terms</u>**. Capitalized terms not defined herein shall have the meanings given such terms in the Rights Agreement.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;3. **<u>Descriptive Headings</u>**. Descriptive headings of the several Sections of this Eleventh Amendment are included for convenience of reference only and shall not control or affect the meaning or construction of any of the provisions hereof.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;4. **<u>Governing Law</u>**. This Eleventh Amendment shall be deemed to be a contract made under the laws of the State of Delaware and for all purposes shall be governed by and construed and enforced in accordance with the laws of such state applicable to contracts to be made and performed entirely within such State.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;5. **<u>Counterparts</u>**. This Eleventh Amendment may be executed in any number of counterparts and each of such counterparts shall for all purposes be deemed to be an original, and all such counterparts shall together constitute but one and the same instrument. A signature to this Eleventh Amendment executed and/or transmitted electronically shall have the same authority, effect and enforceability as an original signature.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;6. **<u>Effect of Eleventh Amendment</u>**. Except as expressly modified by this Eleventh Amendment, the Rights Agreement remains in full force and effect and is hereby ratified and confirmed.

*[Remainder of page left intentionally blank]*

**IN WITNESS WHEREOF**, the parties hereto have caused this Eleventh Amendment to be duly executed as of the date first written above.

---

| | |
|:---|:---|
| **ENZON PHARMACEUTICALS, INC.** | **ENZON PHARMACEUTICALS, INC.** |
| By: | /s/Richard L. Feinstein |
| Name: | Richard L. Feinstein |
| Title: | Chief Executive Officer, Chief Financial Officer and Secretary |
| **CONTINENTAL STOCK TRANSFER & TRUST COMPANY** | **CONTINENTAL STOCK TRANSFER & TRUST COMPANY** |
| By: | /s/Henry Farrell |
| Name: | Henry Farrell |
| Title: | Vice President |

---

*[Signature Page to Eleventh Amendment to Rights Agreement]*

## Exhibit 99.1

**Exhibit 99.1**

**Enzon Announces Reverse Stock Split**

CRANFORD, N.J., March 24, 2026 (GLOBE NEWSWIRE) -- Enzon Pharmaceuticals, Inc. (OTCQB: ENZN) ("Enzon" or the "Company"), today announced that the previously approved 1-for-100 reverse stock split will become effective on March 24, 2026, at 4:30 pm, Eastern Time (the "Effective Time"), and the Company's common stock is expected to begin trading on a reverse stock split-adjusted basis on the OTCQB at market open on March 25, 2026. The Company's common stock is expected to trade under the temporary symbol "ENZND" for 20 trading days. As of the Effective Time, every one hundred (100) shares of the Company's issued and outstanding common stock will be combined into one (1) share of common stock. The par value per share of the Company's common stock will not change. No fractional shares will be issued in connection with the reverse stock split, and stockholders who would otherwise be entitled to a fractional share will receive a proportional cash payment.

The Company's transfer agent, Continental Stock Transfer & Trust, will serve as the exchange agent for the reverse stock split. Registered stockholders holding pre-reverse stock split shares of common stock electronically in book-entry form are not required to take any action to receive post-reverse stock split shares. Those stockholders who hold their shares in brokerage accounts or in "street name" will have their positions automatically adjusted to reflect the reverse stock split, subject to each broker's particular processes, and will not be required to take any action in connection with the reverse stock split.

The reverse stock split was completed to make available authorized shares of common stock needed in connection with the anticipated closing of the previously announced merger with Viskase Companies, Inc., and the related issuances of common stock to be made in connection with the Company's outstanding exchange offer providing for the exchange of the Company's Series C Non-Convertible Redeemable Preferred Stock for shares of the Company's common stock. The timing of the reverse stock split and associated outstanding share amount reduction, as well as the adjustment to the share amounts being issued in the exchange offer, were contemplated and disclosed in the materials previously filed with the United States Securities and Exchange Commission (the "SEC") relating to the exchange offer and the merger. The expiration of the exchange offer is expected to occur at 5:00 pm, Eastern Time on March 24, 2026 and the closing of the merger is expected to occur as soon as practicable thereafter.

**No Offer or Solicitation**

This press release shall not constitute an offer to exchange or the solicitation of an offer to exchange or the solicitation of an offer to purchase any securities, nor shall there be any exchange or sale of securities in any jurisdiction in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such jurisdiction. The exchange offer is being made only through the Schedule TO that was filed with the SEC on January 30, 2026 and the Prospectus/Consent Solicitation/Offer to Exchange that was initially filed on January 28, 2026 and declared effective by the SEC on January 30, 2026 and the complete terms and conditions of the exchange offer are set forth in the Schedule TO and Prospectus/Consent Solicitation/Offer to Exchange.

None of the Company, any of its management or its board of directors, or HKL & Co., LLC, the information agent, or Continental Stock Transfer & Trust Company, the exchange agent, for the exchange offer makes any recommendation as to whether or not holders of shares of Series C Non-Convertible Redeemable Preferred Stock should tender shares of Series C Non-Convertible Redeemable Preferred Stock for exchange in the exchange offer.

**Forward-Looking Statements**

*Certain statements contained in this filing may be considered forward-looking statements within the meaning of the U.S. Private Securities Litigation Reform Act of 1995, including statements regarding the proposed transaction involving Enzon and Viskase Companies, Inc. ("Viskase"), the ability to consummate the proposed transaction, the ability to consummate the exchange offer, the timing of the exchange offer's expiration date, and the ability to quote the common stock of the combined company on the "OTCQB" tier of the OTC market of the OTC Markets Group, Inc. Forward-looking statements generally include statements that are predictive in nature and depend upon or refer to future events or conditions, and include words such as "may," "will," "should," "would," "expect," "anticipate," "plan," "likely," "believe," "estimate," "project," "intend," and other similar expressions among others. Statements that are not historical facts are forward-looking statements. Forward-looking statements are based on current beliefs and assumptions that are subject to risks and uncertainties and are not guarantees of future performance. Actual results could differ materially from those contained in any forward-looking statement as a result of various factors, including, without limitation: (i) the risk that the conditions to the closing of the proposed transaction are not satisfied, including the failure to obtain the necessary approvals for the proposed transaction; (ii) uncertainties as to the timing of the consummation of the proposed transactions, including timing for satisfaction of the closing conditions, and the ability of each of Enzon and Viskase to consummate the proposed transaction; (iii) the ability of Viskase to timely deliver the financial statements required by the Merger Agreement, as amended; (iv) the possibility that other anticipated benefits of the proposed transaction will not be realized, including without limitation, anticipated revenues, expenses, earnings and other financial results, and growth and expansion of the combined company's operations, and the anticipated tax treatment of the combination; (v) potential litigation relating to the proposed transaction that could be instituted against Enzon, Viskase or their respective officers or directors; (vi) possible disruptions from the proposed transaction that could harm Enzon's or Viskase's respective businesses; (vii) the ability of Viskase to retain, attract and hire key personnel; (viii) potential adverse reactions or changes to relationships with customers, employees, suppliers or other parties resulting from the announcement or completion of the proposed transaction; (ix) potential business uncertainty, including changes to existing business relationships, during the pendency of the proposed transaction that could affect Enzon's or Viskase's financial performance; (x) certain restrictions during the pendency of the proposed transaction that may impact Enzon's or Viskase's ability to pursue certain business opportunities or strategic transactions; (xi) the exchange ratio and relative ownership levels as of the closing of the transactions contemplated by the Merger Agreement, as amended; (xii) estimates regarding future revenue, expenses, and capital requirements following the closing of the transactions contemplated by the Merger Agreement, as amended; (xiii) legislative, regulatory and economic developments; (xiv) unpredictability and severity of catastrophic events, including, but not limited to, acts of terrorism, trade wars, or outbreak of war or hostilities, as well as management's response to any of the aforementioned factors; and (xv) such other risks and uncertainties, including those that are set forth in the Registration Statement under the heading "Risk Factors", in Enzon's periodic public filings with the SEC, and in Viskase's annual and quarterly reports posted to Viskase's website. Enzon and Viskase can give no assurance that the conditions to the proposed transactions will be satisfied. Except as required by applicable law, neither Enzon, nor Viskase undertakes any obligation to revise or update any forward-looking statement, or to make any other forward-looking statements, whether as a result of new information, future events or otherwise.*

**About Enzon Pharmaceuticals, Inc.**

Enzon Pharmaceuticals, Inc., together with its subsidiary, is positioned as a public company acquisition vehicle, that has sought to become an acquisition platform.

**For Media Inquiries:**<br>Richard L. Feinstein, CEO and CFO<br> Email: <u>rlfeinsteincpa@enzon.com</u>