Table of Contents

​

​

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-K

​

​

For the Fiscal Year Ended December 31, 2023

OR

​

For the transition period from         to        

Commission file number: 001-36435

Enzon Pharmaceuticals, Inc.

(Exact name of registrant as specified in its charter)

​

​

Registrant’s telephone number, including area code: (732) 980-4500

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

​

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

Common Stock, $0.01 par value

Series A-1 Junior Participating Preferred Stock Purchase Rights

​

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. ☐  Yes     ⌧  No

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Exchange Act. ☐  Yes     ⌧  No

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. ⌧  Yes     ☐  No

Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§ 232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files). ⌧  Yes     ☐  No

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company” and “emerging growth company” in Rule 12b-2 of the Exchange Act:

​

​

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. ☐

Indicate by check mark whether the registrant has filed a report on and attestation to its management’s assessment of the effectiveness of its internal control over financial reporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C. 7262(b)) by the registered public accounting firm that prepared or issued its audit report. ☐

If securities are registered pursuant to Section 12(b) of the Act, indicate by check mark whether the financial statements of the registrant included in the filing reflect the correction of an error to previously issued financial statements. ☐

Indicate by check mark whether any of those error corrections are restatements that required a recovery analysis of incentive-based compensation received by any of the registrant’s executive officers during the relevant recovery period pursuant to §240.10D-1(b). ☐

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Act). ☐  Yes     ☒  No

The aggregate market value of the Common Stock, $0.01 par value per share (“the Common Stock”), held by non-affiliates of the registrant was approximately $7,591,503 as of June 30, 2023, based upon the closing sale price quoted on the OTCQX market of the OTC Markets Group, Inc. of $0.20 per share reported for such date. Shares of Common Stock held by each executive officer and director and certain beneficial owners of 10% or more of the Common Stock of the registrant as of June 30, 2023 have been excluded in that such shares may be deemed to be owned by affiliates. This determination of affiliate status is not necessarily a conclusive determination for other purposes.

There were 74,214,603 shares of Common Stock issued and outstanding as of March 12, 2024.

DOCUMENTS INCORPORATED BY REFERENCE

If the registrant files a definitive proxy statement relating to its 2024 Annual Meeting of Stockholders with the Commission not later than 120 days after December 31, 2023, portions of such definitive proxy statement will be incorporated by reference into Part III of this Annual Report on Form 10-K where indicated. However, if such definitive proxy statement is not filed with the Commission in such 120-day period, the registrant will file an amendment to this Annual Report on Form 10-K with the Commission not later than the end of such 120-day period to include the information required by Part III of Form 10-K.

​

​

Table of Contents

ENZON PHARMACEUTICALS, INC.

2023 Annual Report on Form 10-K

Table of Contents

​

2

Table of Contents

Unless the context requires otherwise, references in this Annual Report on Form 10-K to “Enzon,” the “Company,” “we,” “us,” or “our” and similar terms mean Enzon Pharmaceuticals, Inc. and its subsidiaries.

This Annual Report on Form 10-K contains forward-looking statements within the “safe harbor” provisions of the Private Securities Litigation Reform Act of 1995. All statements contained in this Annual Report on Form 10-K, other than statements that are purely historical, are forward-looking statements. Forward-looking statements can be identified by the use of forward-looking terminology such as “believes,” “expects,” “may,” “will,” “should,” “could,” “potential,” “anticipates,” “estimates,” “plans,” “would,” or “intends” or the negative thereof, or other variations thereof, or comparable terminology, or by discussions of strategy. Forward-looking statements are based upon management’s present expectations, objectives, anticipations, plans, hopes, beliefs, intentions or strategies regarding the future and are subject to risks and uncertainties that could cause actual results, events or developments to be materially different from those indicated in such forward-looking statements, including the risks and uncertainties set forth in Item 1A. Risk Factors of this Annual Report on Form 10-K. These risks and uncertainties should be considered carefully and readers are cautioned not to place undue reliance on such forward-looking statements. We cannot assure that the future results covered by the forward-looking statements will be achieved. All information in this Annual Report on Form 10-K speaks only as of the date of the filing of this report, unless otherwise indicated. We do not intend to update this information to reflect events after the date of this report.

Our website is located at www.enzon.com. Copies of our Annual Reports on Form 10-K, our Quarterly Reports on Form 10-Q, our Current Reports on Form 8-K and our other reports filed with the Securities and Exchange Commission (the “SEC”) can be obtained, free of charge, as soon as reasonably practicable after such material is electronically filed with, or furnished to the SEC, by calling (732) 980-4500, by clicking the SEC Filings link from the Investors and Media page on our website at www.enzon.com or directly from the SEC’s website at www.sec.gov. Our website and the information contained therein or connected thereto are not incorporated into this Annual Report on Form 10-K.

​

3

Table of Contents

UNITED STATES SECURITIES AND EXCHANGE COMMISSION

FORM 10-K

ENZON PHARMACEUTICALS, INC.

PART I.

Item 1. Business

OVERVIEW

Enzon Pharmaceuticals, Inc. (together with its subsidiaries, the “Company,” “Enzon,” “we” or “us”) is positioned as a public company acquisition vehicle, where we can become an acquisition platform and potentially utilize our net operating loss carryforwards (“NOLs”) in an effort to enhance stockholder value.

In September 2020, we initiated a rights offering (the “Rights Offering”) for our common and preferred stock, which closed in October 2020 (see below and Note 12 to our Consolidated Financial Statements), and we realized $43.6 million in gross proceeds. This has enabled us to embark on our plan to potentially realize the value of our approximately $102.5 million NOLs by acquiring businesses or assets, although there can be no assurance that we will be able to realize all or any portion of such value. To protect the NOLs, in August 2020, our Board of Directors (the “Board”) adopted a Section 382 rights plan (see Note 11 to our Consolidated Financial Statements).

Historically, we have received royalty revenues from licensing arrangements with other companies primarily related to sales of certain drug products that utilized Enzon’s proprietary technology. In recent years, we have had no clinical operations and limited corporate operations. We have a marketing agreement relating to the drug Vicineum, which, if approved, will potentially generate milestone and royalty payments to us in the future. Currently, our licensee for this drug has announced that it is seeking a partner for further development of Vicineum. Accordingly, we cannot assure you that we will earn material future royalties or milestones from Vicineum or any other licensed patent.

Acquisition Activities

Our Board and our management are actively involved in pursuing, sourcing, reviewing, and evaluating various potential acquisition transactions consistent with our strategy. Our management and our Board have originated a number of potential acquisition opportunities and engaged in discussions with certain potential acquisition targets and financial advisors on behalf of various individual entities, while continuing to evaluate such potential transactions, including those transactions that could result in a change of control of us. We will continue to update our stockholders as material developments arise.

Royalty and Milestone Agreements and Revenues

Prior to 2017, we received royalty revenues from sales of PegIntron, which is marketed by Merck & Co., Inc. (“Merck”). In 2022 and 2023 net royalties from PegIntron have been minimal. There is a dispute with Merck regarding royalties (see Note 4 to our Consolidated Financial Statements). We have a licensing agreement regarding SC Oncaspar and certain other drugs.

During the years ended December 31, 2023 and 2022, we received a license maintenance fee of approximately $0 and $26,000, respectively, from Amgen, Inc. in payment of a worldwide, royalty-free non-exclusive right to license Vicineum. (See Note 1 to our Consolidated Financial Statements.)

Patents and Intellectual Property Rights

We have a portfolio of issued U.S. patents, many of which have foreign counterparts. None of these has generated significant royalties in recent years, except for two milestone payments received in connection with Vicineum. The patent related to PegIntron (peginterferon alfa-2b) expired in all jurisdictions, except Chile, which will expire in 2024. We do not expect to generate material royalties from any of our existing patents.

EMPLOYEES AND EXECUTIVE OFFICERS

We currently have no employees. Our executive officer provides services to us on a consulting basis.

4

Table of Contents

Item 1A. Risk Factors

You should carefully consider the following risk factors, as well as other information in this Annual Report, including our financial statements and the related notes and “Management’s Discussion and Analysis of Financial Condition and Results of Operations”, as well as our other public filings. Our business, financial condition and results of operations may be impacted by one or more of the following factors, any of which could cause actual results to vary materially from historical and current results or anticipated future results.

Risks Relating to the Company and its Operations

Our search for a business, company or assets to acquire or in which to invest may be unsuccessful, or it could result in a change of control, and we may fail to utilize the proceeds of our Rights Offering and/or realize the value of our NOLs.

We are positioned as a public company acquisition vehicle, where we can become an acquisition platform and potentially utilize our NOLs and enhance stockholder value. Although we may acquire businesses, entities or revenue streams that could generate sufficient income so that we can utilize our approximately $102.5 million in federal NOLs, there can be no assurance we will be able to do so. In addition, we do not have any current plans, arrangements or understandings with respect to any acquisitions or investments, and we may pursue acquisitions that could result in a change of control of us. Although we have had significant discretion in the use of the net proceeds of our Rights Offering, it is possible that we may not utilize such proceeds and if a transaction is pursued that results in a change of control, as defined in the Certificate of Designation of the Series C Non-Convertible Preferred Stock, holders of the Series C Non-Convertible Redeemable Preferred Stock will be entitled to redemption rights, and if exercised would require the Company to redeem such preferred stock. Further, if such change of control occurs, it would likely substantially limit the utilization of our NOLs. We cannot assure you that we will be able to realize the value of all or any of our NOLs.

Our sources of revenue are limited and, as a result of our cash reserves, we expect only limited revenue and profitability for the foreseeable future; while we increased our cash reserve by completing the Rights Offering and generate revenue from such cash reserve, unanticipated liabilities and expenses could adversely affect our ability to engage in a public company acquisition or investment, as currently intended, or to continue operations.

Prior to 2023, we incurred losses and, in 2023, our source of revenue was from interest income. We received approximately $43.1 million of net proceeds in the fourth quarter of 2020 from the Rights Offering, which we are using to position us as a public company acquisition vehicle, unless and until we can consummate an acquisition or investment that generates income, and other than interest income, we do not anticipate generating any additional cash or revenues. As interest rates may fluctuate in the future, there can be no assurance that we will continue to receive interest income at our existing levels, or at levels that allow us to achieve a profit. Accordingly, there can be no assurance that we will continue to generate a profit based on our interest income. In addition, we have been informed by Merck that there will likely be no or minimal additional sales of PegIntron and we would likely receive no further significant royalties, although we may remain potentially liable to Merck for product returns and rebates. Based on current estimates, we do not expect any liability for those returns and rebates to be material. Moreover, our right to receive royalty revenues from other products is limited and we currently do not intend to acquire new sources of royalty revenues. For those remaining existing or potential sources of royalty revenue, our licensees may be unable to maintain regulatory approvals for currently licensed products or obtain regulatory approvals for new products. Safety issues could also result in the failure to maintain regulatory approvals or decrease revenues.

While we have substantially reduced our operating expenses, including ceasing our research and development activities, eliminating our workforce in favor of independent contractors, and discontinuing our significant lease commitments, we may incur unanticipated liabilities or expenses, including expenses to defend unasserted product liability claims or greater than expected liabilities for PegIntron and expenses incurred in our search for a target business to acquire or in which to invest. Any such expenses or liabilities could impact the availability of assets that we expect to use to fund future operations or adversely affect our ability to pay dividends or make distributions to shareholders upon a liquidation of the Company.

We have outsourced all corporate functions, which makes us more dependent on third parties to perform these corporate functions.

We have outsourced all corporate functions, which makes us more dependent on third parties for the performance of these functions. To the extent that we are unable to effectively reallocate employee responsibilities, retain key officers as consultants, maintain effective internal control over financial reporting and effective disclosure controls and procedures, establish and maintain agreements

5

Table of Contents

with competent third-party contractors on terms that are acceptable to us, or effectively manage the work performed by any retained third-party contractors, our ability to manage the operations effectively could be compromised.

While we may, potentially, acquire businesses, entities or revenue streams that could generate sufficient income so that we can utilize our NOLs, we may be unable to do so and, accordingly, we may be unable to realize our deferred income tax assets.

The ultimate realization of our deferred income tax assets is dependent upon generating future taxable income, executing tax planning strategies, and reversals of existing taxable temporary differences. We have recorded a partial valuation allowance against our deferred income tax assets, which may fluctuate as conditions change. While we are positioned as a public company acquisition vehicle and may acquire businesses, entities or revenue streams that could generate sufficient income so that we can utilize our NOLs, we cannot provide any assurance that we will be able to do so. If we fail to do so, approximately 97% of our current federal NOLs will expire by 2036 and more than 90% of our current federal NOLs will expire by the end of 2031. As a result of the expiration dates of our NOLs and our efforts to date to identify acquisition candidates, we may consider transactions that could result in a change of control of us in an effort to enhance stockholder value.

Our ability to utilize our NOLs to offset our future taxable income and/or to recover previously paid taxes would be limited or could be non-existent if we were to undergo an “ownership change” within the meaning of Section 382 of the Internal Revenue Code. In general, an “ownership change” occurs whenever the percentage of the stock of a corporation owned by “5-percent shareholders” (within the meaning of Section 382 of the Internal Revenue Code) increases by more than 50 percentage points over the lowest percentage of the stock of such corporation owned by such “5-percent shareholders” at any time over the testing period.

An ownership change under Section 382 of the Internal Revenue Code would establish an annual limitation to the amount of NOLs we could utilize to offset our taxable income in any single year. The application of these limitations might prevent full utilization of the deferred tax assets attributable to our NOLs. Although we have adopted a Section 382 rights plan in an effort to protect stockholder value by attempting to protect against a possible limitation on our ability to use our NOLs, we cannot assure you that we will not undergo an ownership change within the meaning of Section 382. (See Notes 9 and 11 to the Consolidated Financial Statements.)

Risks Relating to Our Common Stock

Our common stock ranks junior to our Series C Preferred Stock.

With respect to the payment of cash dividends and amount payable in the event our liquidation, dissolution or winding up, our common stock will rank junior to our Series C Non-Convertible Redeemable Preferred Stock (“Series C Preferred Stock”). This means that, unless full dividends have been (i) paid, (ii) redeemed in an amount in excess of the initial liquidation value of $1,000 per share of Series C Preferred Stock or (iii) set aside for payment on all outstanding Series C Preferred Stock for all dividends or increases in the liquidation value in excess of the initial liquidation amount of $1,000 of such Series C Preferred Stock, no cash dividends may be declared or paid on our common stock. Likewise, in the event of our voluntary or involuntary liquidation, dissolution or winding up, no distribution of our assets may be made to holders of our common stock until we have paid to the holders of our Series C Preferred Stock the liquidation preference related to such Series C Preferred Stock, plus in each case any accrued and unpaid dividends.

In addition, the holders of Series C Preferred Stock have the right to demand that we redeem their shares in the event that we undergo a change of control. Accordingly, if such demands were made, there could be limited or no cash available to declare or make any dividends to holders of our common stock.

The interests of our significant stockholders may conflict with the interests of other stockholders.

Mr. Carl C. Icahn, directly and indirectly, beneficially owns approximately 49% of the outstanding shares of our common stock, as well as approximately 98% of the outstanding Series C Preferred Stock. Mr. Icahn may have interests that are different from, in addition to or not always consistent with our interests or with the interests of our other common or preferred stockholders. To the extent that conflicts of interest may arise between us and Mr. Icahn and his affiliates, those conflicts may be resolved in a manner adverse to us or our other stockholders. In addition, the existence of significant stockholders may have the effect of making it difficult for, or may discourage or delay, a third party from seeking to acquire a majority of our outstanding common stock, which may adversely affect the market price of our common stock. In addition, such stockholders may exert significant influence over our operations. Accordingly, the interests of these significant stockholders may not always coincide with our interests or the interests of other stockholders, or otherwise be in the best interests of us or all stockholders.

6

Table of Contents

The price of our common stock has historically been volatile and may decline significantly if we are unable to consummate a business acquisition or investment.

Historically, the market price of our common stock has fluctuated over a wide range for a variety of reasons, including Company-specific factors and global and industry-wide conditions and events such as the COVID-19 pandemic and resulting recession, as well as the fact that only a few stockholders, in the aggregate, hold more than a majority of our common stock, and, therefore, there is a small public float with limited trading activity in our common stock. In the future, the value of our common stock may be impacted by our lack of royalty revenues, our ability to monetize our remaining assets, including our NOLs, and any unexpected liabilities or expenses that impact our continued operations, our ability to pay dividends or make distributions to our stockholders and the success of any future activities which we undertake, including our ability to consummate a business acquisition or investment.

In addition, financings that may be available to us under current market conditions frequently involve sales at prices below the prices at which our common stock currently trades on the OTCQX, as well as the issuance of warrants or convertible equity that require exercise or conversion prices that are calculated in the future at a discount to the then market price of our common stock.

Our common stock is quoted on the OTCQX market of the OTC Markets Group, Inc., which has a very limited trading market and, therefore, market liquidity for our common stock is low and our stockholders’ ability to sell their shares of our common stock may be limited.

Our common stock is quoted on the OTCQX market of the OTC Markets Group, Inc. and the quotation of our common stock on the OTCQX market does not assure that a liquid trading market exists or will develop. Stocks traded on the OTCQX market generally have very limited trading volume and exhibit a wider spread between the bid/ask quotations than stocks traded on national exchanges. Moreover, a significant number of institutional investors have investment policies that prohibit them from trading in stocks on the OTCQX marketplace. As a result, investors may find it difficult to dispose of, or to obtain accurate quotations of the price of, our common stock. This significantly limits the liquidity of our common stock and may adversely affect the market price of our common stock.

We do not currently, and are not expected in the future to, meet the listing standards of any national exchange. In addition, on January 17, 2024, we received a compliance deficiency notice from the OTCQX indicating that our stock’s bid price had closed below $0.10 for more than 30 consecutive calendar days and therefore no longer met the continued listing qualifications of the OTCQX. We were granted a 180-calendar day cure period, or until July 15, 2024, to regain compliance with the minimum bid price requirement. In order to regain compliance, our bid price will need to stay at or above $0.10 for ten consecutive trading days. We will continue to monitor our compliance during the cure period and could undertake specific actions to address this minimum bid price deficiency, including but not limited to a reverse split of our shares of common stock. Alternatively, at the end of such cure period, it is possible we would be eligible for trading on the OTCQB and may apply for listing on such platform prior to such time. There can be no assurance that we will be able to become compliant with the continued listing qualifications rules of the OTCQX or become eligible to trade on OTCQB, and in such events, it is expected our shares of common stock would be eligible to trade on the OTC Pink Market.. As a result, investors must bear the economic risk of holding their shares of our common stock for an indefinite period of time. In the future, our common stock could become subject to “penny stock” rules which impose additional disclosure requirements on broker-dealers and could further negatively impact market liquidity for our common stock and our stockholders’ ability to sell their shares of our common stock.

The declaration of common stock dividends is within the discretion of our Board, subject to any applicable limitations under Delaware corporate law, as well as the requirements of the Series C Preferred Stock. Our ability to pay dividends in the future depends on, among other things, our fulfillment of the conditions of the Series C Preferred Stock, declining royalty revenues, our ability to acquire other revenue sources and our ability to manage expenses, including costs relating to our ongoing operations.

The declaration of dividends is within the discretion of our Board, subject to any applicable limitations under Delaware corporate law, and, therefore, our Board could decide in the future not to declare dividends. In addition, as described elsewhere, our common stock ranks junior to the Series C Preferred Stock, and we cannot declare or pay cash dividends on our common stock unless we satisfy the dividend requirements of such Series C Preferred Stock. Also, our ability to pay dividends in the future depends on, among other things, interest rates, our future revenues, including any revenues from existing and any future royalties and/or milestone payments, our ability to acquire other revenue sources and our ability to manage expenses, including costs relating to our ongoing operations. We expect little or no future royalties from existing products for which we have the right to receive royalties. In addition, while we may acquire or invest in businesses, entities or revenue streams and we may be entitled to a share of milestone and royalty payments from

7

Table of Contents

the approval and sale of Vicineum, we cannot assure you that we will be able to do so or that we will have sufficient royalty or milestone revenues to be able to pay dividends in the future.

We have adopted a Section 382 rights plan, which may discourage a corporate takeover.

On August 14, 2020, our Board of Directors adopted the Section 382 rights plan and declared a dividend distribution of one right for each outstanding share of our common stock to stockholders of record at the close of business on August 24, 2020. Each share of our common stock issued thereafter will also include one right. Each right entitles its holder, under certain circumstances, to purchase from us one one-thousandth of a share of our Series A-1 Junior Participating Preferred Stock at an exercise price of $1.20 per right, subject to adjustment.

The Board adopted the Section 382 rights plan in an effort to protect stockholder value by attempting to protect against a possible limitation on our ability to use our NOLs. We may utilize these NOLs in certain circumstances to offset future United States taxable income and reduce our United States federal income tax liability. Because the Section 382 rights plan could make it more expensive for a person to acquire a controlling interest in us, it could have the effect of delaying or preventing a change in control even if a change in control was in our stockholders’ interest.

Anti-takeover provisions in our charter documents and under Delaware corporate law may make it more difficult to acquire us, even though such acquisitions may be beneficial to our stockholders.

In addition to our Section 382 rights plan, provisions of our certificate of incorporation and bylaws, as well as provisions of Delaware corporate law, could make it more difficult for a third party to acquire us, even though such acquisitions may be beneficial to our stockholders. These anti-takeover provisions include:

The provisions described above, our Section 382 rights plan and provisions of Delaware corporate law relating to business combinations with interested stockholders, along with the significant amount of common stock beneficially owned by Mr. Icahn, may discourage, delay or prevent a third party from acquiring us. These provisions may also discourage, delay or prevent a third party from acquiring a large portion of our securities, or initiating a tender offer, even if our stockholders might receive a premium for their shares in the acquisition over the then current market price.

Risks Related to the Series C Preferred Stock

In the event of any dissolution, liquidation, or winding up of our Company, we may not be able to make distributions or payments in full to all the holders of the Series C Preferred Stock or, if required, we may not be able to redeem such shares.

The Series C Preferred Stock ranks senior to our common stock, but we may in the future issue one or more series of preferred stock that ranks senior to, junior to or pari passu with our Series C Preferred Stock. In the event of any dissolution, liquidation, winding up or change of control of our Company, we may not be able to make distributions or payments in full to all the holders of the Series C Preferred Stock or, if requested by such holders upon a change of control, to redeem the Series C Preferred Stock, in which case holders of the Series C Preferred Stock could lose some or all of the entire value of their investment.

The dividends on our Series C Preferred Stock can be paid either in cash or be paid in kind by increasing the liquidation value of the shares of Series C Preferred Stock.

The terms of the Series C Preferred Stock allow dividends on the shares of Series C Preferred Stock to be paid either in cash or be paid in kind by increasing the liquidation value of the shares of Series C Preferred Stock and, therefore, allow the repayment of the principal and accrued dividends on the Series C Preferred Stock to be deferred until the earliest of the redemption of the Series C

8

Table of Contents

Preferred Stock or upon our dissolution, liquidation or winding up. We may not have enough capital to repay the full amount of the principal and accrued dividends when the payment of principal and accrued dividends on the Series C Preferred Stock becomes due.

The Series C Preferred Stock is equity and is subordinate to our existing and future indebtedness and other liabilities, and your interests may be diluted in the event we issue additional shares of preferred stock.

Shares of the Series C Preferred Stock represent equity interests and do not constitute indebtedness. As such, the Series C Preferred Stock will rank junior to all of our indebtedness and other non-equity claims of our creditors with respect to assets available to satisfy our claims, including in our liquidation, dissolution or winding up. Our future debt, if any, may include restrictions on our ability to pay distributions to preferred stockholders. Unlike indebtedness, where principal and interest would customarily be payable on specified due dates, in the case of preferred stock such as the Series C Preferred Stock, dividends are payable only if declared by our Board of Directors (or a duly authorized committee thereof). Our ability to pay dividends on the Series C Preferred Stock may be limited by the terms of our agreements governing any future indebtedness and by the provisions of any other future agreements.

Subject to limitations prescribed by Delaware law and our charter, our Board of Directors is authorized to issue, from our authorized but unissued shares of capital stock, preferred stock in such classes or series as our Board of Directors may determine and to establish from time to time the number of shares of preferred stock to be included in any such class or series. The issuance of additional shares of Series C Preferred Stock or additional shares of preferred stock designated as ranking on parity with the Series C Preferred Stock would dilute the interests of the holders of shares of the Series C Preferred Stock, and the issuance of shares of any class or series of our capital stock expressly designated as ranking senior to the Series C Preferred Stock or the incurrence of additional indebtedness could affect our ability to pay distributions on, redeem or pay the liquidation preference on the Series C Preferred Stock.

The Series C Preferred Stock is not convertible into common stock.

The Series C Preferred Stock is not convertible into shares of common stock and, therefore, holders of Series C Preferred Stock have no rights with respect to shares of our common stock. In addition, the Series C Preferred Stock accrues dividends at a fixed rate. Accordingly, an increase in market price of our common stock will not necessarily result in an increase in the value of the Series C Preferred Stock. The value of the Series C Preferred Stock may depend more on dividend and interest rates for other preferred stock, commercial paper and other investment alternatives and our actual and perceived ability to pay dividends on, and in the event of dissolution satisfy the liquidation preference with respect to, the Series C Preferred Stock.

Holders of shares of Series C Preferred Stock have no voting rights.

Except as otherwise provided by law, the holders of Series C Preferred Stock have no special voting rights and their consent will not be required for taking any corporate action. As a result, all matters submitted to stockholders will be decided by the vote of holders of our common stock. Holders of Series C Preferred Stock have no ability to influence corporate matters and, as a result, we may take actions that holders of our Series C Preferred Stock do not view as preferable.

There is no public market for the Series C Preferred Stock.

There is no established public trading market for the Series C Preferred Stock, and we do not expect a market to develop. We do not currently intend to apply for listing of the Series C Preferred Stock on any securities exchange or recognized trading system. Purchasers of the Series C Preferred Stock may be unable to resell their shares of Series C Preferred Stock or sell them only at an unfavorable price for an extended period of time, if at all.

 Item 1B. Unresolved Staff Comments

Not applicable.

​

Item 1C. Cybersecurity

As we have positioned ourselves as a public company acquisition vehicle, and have limited operations, we do not have any significant operations that face cybersecurity threats. Although we do depend on the digital technologies of third parties, and any deliberate attacks on, or security breaches in, systems or infrastructure that we utilize, including those of third parties, could lead to corruption or misappropriation of our assets, information and sensitive or confidential data, we do not consider that we face significant cybersecurity risk and have not adopted any cybersecurity risk management program or formal processes for assessing cybersecurity risk. Our board of directors is generally responsible for the oversight of risks from cybersecurity threats, if there is any. In fiscal year

9

Table of Contents

2023, we did not identify any cybersecurity threats that have materially affected or are reasonably likely to materially affect our business strategy, results of operations, or financial condition.

Item 2. Properties

We maintain our principal executive offices at 20 Commerce Drive, Suite 135, Cranford, New Jersey, 07016 through a services agreement with Regus Management Group, LLC.

​

Item 3. Legal Proceedings

From time to time, we are engaged in litigation arising in the ordinary course of our business. We are not presently a party to any litigation that we believe to be material and we are not aware of any pending or threatened litigation against us that we believe could have a material adverse effect on our business, operating result, financial condition or cash flows.

Item 4. Mine Safety Disclosures

Not applicable.

​

10

Table of Contents

PART II.

Item 5. Market for Registrant’s Common Equity, Related Stockholder Matters, and Issuer Purchases of Equity Securities

Market Information

Since August 9, 2016, our common stock has been quoted for trading on the OTCQX market of the OTC Markets Group, Inc. under the trading symbol “ENZN.”

Over-the-counter market quotations reflect inter-dealer prices, without retail mark-up, markdown or commission and may not represent actual transactions.

Holders

As of March 12, 2024, there were 733 holders of record of our common stock, which does not reflect persons or entities that hold the common stock in nominee or “street” name through various brokerage firms and financial institutions.

Dividends

The declaration of dividends is within the discretion of our Board, subject to any applicable limitations under Delaware corporate law, and therefore our Board could decide in the future not to declare dividends. We did not pay any cash dividends to our common stockholders in 2023 and can provide no assurance that our Board will declare any cash dividends payable to our common stockholders in the future. In addition, as our common stock ranks junior to the Series C Preferred Stock, unless full dividends have been (i) paid, (ii) redeemed in an amount in excess of the initial liquidation value of $1,000 per share of Series C Preferred Stock or (iii) set aside for payment on all such outstanding Series C Preferred Stock for all dividends or increases in the liquidation value in excess of the initial liquidation amount of $1,000 of such Series C Preferred Stock, no cash dividends may be declared or paid on our common stock. On an annual basis, our Board may, at its sole discretion, cause a dividend with respect to the Series C Preferred Stock to be paid in cash to the holders in an amount equal to 3% of the liquidation preference as in effect at such time. If the dividend is not so paid in cash, the liquidation preference will be adjusted and increased annually by an amount equal to 5% of the liquidation preference per share as in effect at such time, that is not paid in cash to the holders on such date. Also, our ability to pay dividends in the future depends on, among other things, our future revenues from existing royalties and/or milestone payments, our ability to acquire other revenue sources and our ability to manage expenses, including costs relating to our ongoing operations.

On December 28, 2023, our Board declared a cash dividend of 3% of the liquidation preference at December 31, 2022 ($42,483,286) of the Series C Preferred Stock, aggregating approximately $1,275,000 ($31.86 per share). Such dividend was paid on January 17, 2024 to the holders of record of our Series C Preferred Stock as of January 10, 2024.

Repurchase of Equity Securities

Not applicable.

Item 6.  Reserved

Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations

The following discussion of our financial condition and results of operations should be read together with our consolidated financial statements and notes to those statements included elsewhere in this Annual Report on Form 10-K.

11

Table of Contents

Forward-Looking Information and Factors That May Affect Future Results

The following discussion contains forward-looking statements within the “safe harbor” provisions of the Private Securities Litigation Reform Act of 1995. All statements contained in the following discussion, other than statements that are purely historical, are forward-looking statements. Forward-looking statements can be identified by the use of forward-looking terminology such as “believes,” “expects,” “may,” “will,” “should,” “could,” “potential,” “anticipates,” “estimates,” “plans,” “would,” or “intends” or the negative thereof, or other variations thereof, or comparable terminology, or by discussions of strategy. Forward-looking statements are based upon management’s present expectations, objectives, anticipations, plans, hopes, beliefs, intentions or strategies regarding the future and are subject to risks and uncertainties that could cause actual results, events or developments to be materially different from those indicated in such forward-looking statements, including the risks and uncertainties set forth in Item 1A. Risk Factors. These risks and uncertainties should be considered carefully and readers are cautioned not to place undue reliance on such forward-looking statements. As such, we cannot assure you that the future results covered by the forward-looking statements will be achieved.

The percentage changes throughout the following discussion are based on amounts stated in thousands of dollars.

Overview

During 2020, the Company adopted a Section 382 rights plan and completed a Rights Offering, each as further described below. As a result of the successful completion of the Rights Offering, we are positioned as a public company acquisition vehicle, where we can become an acquisition platform and potentially utilize our NOLs and enhance stockholder value. We may acquire businesses, entities or revenue streams that could generate sufficient income so that we can utilize our approximately $102.5 million of federal NOLs. To date, we have not identified any actionable acquisition candidates and, while we expect that, ultimately, we will be successful in realizing the value of our NOLs, we cannot assure you that we will be able to do so.

Prior to 2017, the primary source of our royalty revenues was derived from sales of PegIntron, which is marketed by Merck. We currently have no clinical operations and limited corporate operations. We have no intention of resuming any clinical development activities. We had no revenues from sales of PegIntron for the years ended December 31, 2023 and 2022, respectively, net of the effects of Merck’s adjustments for recoupment of previously overpaid royalties.

We have a marketing agreement with Micromet AG, now part of Amgen, Inc. (the “Micromet Agreement”), pursuant to which we may be entitled to certain milestone and royalty payments if Vicineum, a drug that was being developed by Sesen, Inc., (Sesen”) is approved for the treatment of non-muscle invasive bladder cancer. Sesen announced that it had completed a merger with Carisma Therapeutics Inc. (“Carisma”) and that the combined company will focus on the advancement of Carisma’s proprietary cell therapy for the treatment of cancer and other disorders and that that it intends to seek a partner for the further development of Vicineum.

Due to the challenges associated with developing and obtaining approval for drug products, and the lack of our involvement in the development and approval process, there is substantial uncertainty as to whether we will receive any milestone or royalty payments under the Micromet Agreement. We will not recognize revenue until all revenue recognition requirements are met.

12

Table of Contents

 We may be entitled to certain potential future milestone payments contingent upon the achievement of certain regulatory approval-related milestones by third-party licensees. We cannot assure you that we will receive any milestone payments resulting from our agreements with any of our third-party licensees or that any sales of related products will be made. We will not recognize revenue from any of our third-party licensees until all revenue recognition requirements are met.

Results of Operations (in thousands of dollars):

​

Overview

The following table summarizes our royalties earned in 2023 and 2022:

Royalties and Milestones Revenues (in thousands of dollars):

​

In 2023 and 2022, we earned no net royalties and milestones from Sesen. The revenues in 2023 and 2022 were approximately $0 and $26,000, respectively, from license fees from Amgen, Inc. in payment of a worldwide, royalty-free non-exclusive right to license Vicineum. Our right to receive royalties on U.S. and European sales of PegIntron expired in 2016 and 2018, respectively, expired in Malaysia in 2020, expired in Japan in 2021 and will expire in Chile in 2024.

At December 31, 2023 and 2022, we recorded a liability to Merck of approximately $331,000 based primarily on Merck’s assertions regarding recoupments related to prior returns and rebates, as discussed in Note 4 to the Consolidated Financial Statements.

We believe that we will receive no additional royalties from Merck and may incur additional chargebacks from returns and rebates in amounts that, based on current estimates, are not believed to be material. As reported by Merck, in recent years, sales declines were driven by lower volumes in nearly all regions, as the availability of new therapeutic options resulted in continued loss of market share.

Interest and Dividend Income (in thousands of dollars):

​

Interest and dividend income reflects income earned on the invested cash we received from the $43.6 million of proceeds from our rights offering (see Note 12 to our Consolidated Financial Statements) and other cash on hand. Interest and dividend income increased by approximately $1,615,000, or 250%, to $2,261,000 for 2023 from $646,000 for 2022. The increase in interest and dividends income is attributable to the higher rates of interest in 2023 as compared with 2022.

13

Table of Contents

General and Administrative Expenses (in thousands of dollars):

​

For the year ended December 31, 2023, general and administrative expenses were approximately $1,044,000, a decrease of approximately $14,000 (1%) from $1,058,000 in the prior year.

In 2023 and 2022, general and administrative expenses consisted primarily of consulting fees for executive services and outside professional services for accounting, audit, tax and legal services.

Income Taxes

As a result of our income, primarily from interest, exceeding our expenses for the year ended December 31, 2023, we realized approximately $1,217,000 in pre-tax book income before utilization of NOLs. We utilized approximately $1.2 million of our NOLs. We are projecting 2024 pre-tax book income due to interest rates on our short-term cash investments and the absence of any acquisitions at this time. Upon review of positive and negative evidence in determining a partial reversal of the valuation allowance, the Company has concluded that a partial reversal of the valuation allowance is necessary. Interest rates may fluctuate throughout 2024, however, they are not expected in the near term to return to the low rates of the past creating a projected taxable income position. Therefore, the Company will partially reverse the valuation allowances as of December 31, 2023. A deferred tax benefit of $157,000 was recorded during the year ended December 31, 2023. We may acquire businesses, entities or revenue streams that will generate sufficient income so that we can utilize our approximately $102.5 million NOLs. While we anticipate that, ultimately, we could be successful in realizing the value of our NOLs, we cannot assure you that we will be able to do so.

Our management will continue to assess the need for this valuation allowance and will make adjustments when appropriate. Additionally, our management believes that our NOLs will not be limited by any changes in the Company’s ownership as a result of the successful completion of the Rights Offering. (See Note 13 to the Consolidated Financial Statements.)

These projections and beliefs are based upon a variety of estimates and numerous assumptions made by our management with respect to, among other things, interest rates, forecasted sales of the drug products for which we have the right to receive royalties, our ability to acquire businesses, entities or revenue streams that could generate sufficient income so that we can utilize our NOLs and other matters, many of which are difficult to predict, are subject to significant uncertainties and are beyond our control. As a result, we cannot assure you that the estimates and assumptions upon which these projections and beliefs are based will prove accurate, that the projected results will be realized or that the actual results will not be substantially higher or lower than projected.

14

Table of Contents

Section 382 Rights Plan

On August 14, 2020, in an effort to protect stockholder value by attempting to protect against a possible limitation on our ability to use our NOLs, our Board of Directors adopted a Section 382 rights plan and declared a dividend distribution of one right for each outstanding share of the Company’s common stock to stockholders of record at the close of business on August 24, 2020. Accordingly, holders of the Company’s common stock own one preferred stock purchase right for each share of common stock owned by such holder. The rights are not immediately exercisable and will become exercisable only upon the occurrence of certain events as set forth in the Section 382 rights plan. If the rights become exercisable, each right would initially represent the right to purchase from us one one-thousandth of a share of our Series A-1 Junior Participating Preferred Stock, par value $0.01 per share, for a purchase price of $1.20 per right. If issued, each fractional share of Series A-1 Junior Participating Preferred Stock would give the stockholder approximately the same dividend, voting and liquidation rights as does one share of the Company’s common stock. However, prior to exercise, a right does not give its holder any rights as a stockholder of the Company, including any dividend, voting or liquidation rights. The rights will expire on the earliest of (i) the close of business on June 2, 2024 (unless that date is advanced or extended by the Board of Directors), (ii) the time at which the rights are redeemed or exchanged under the Section 382 rights plan, (iii) the close of business on the day of repeal of Section 382 of the Internal Revenue Code or any successor statute and (iv) the close of business on the first day of a taxable year of the Company to which our Board of Directors determines that no NOLs may be carried forward.

Rights Offering

On September 1, 2020, our Board of Directors approved the Rights Offering consisting of shares of Series C Preferred Stock and shares of the Company’s common stock. On October 9, 2020, the Rights Offering was completed and, as a result, we realized gross proceeds of approximately $43.6 million, issued 40,000 shares of Series C Preferred Stock and 30,000,000 shares of common stock such that there is currently an aggregate of 40,000 shares of Series C Preferred Stock and 74,214,603 shares of common stock outstanding. (See Note 12 to the Consolidated Financial Statements.)

With regard to the Series C Preferred Stock, on an annual basis, the Company’s Board of Directors may, at its sole discretion, cause a dividend with respect to the Series C Preferred Stock to be paid in cash to the holders in an amount equal to 3% of the liquidation preference as in effect at such time (initially $1,000 per share). If the dividend is not so paid in cash, the liquidation preference is adjusted and increased annually by an amount equal to 5% of the liquidation preference per share as in effect at such time, that is not paid in cash to the holders on such date. Holders of Series C Preferred Stock do not have any voting rights and the Series C Preferred Stock is not convertible into shares of our common stock. The initial liquidation value of the Series C Preferred Stock was $1,000 per share. On December 28, 2023, our Board declared a cash dividend of 3% of the liquidation preference ($42,483,286) of the Series C Preferred Stock, aggregating approximately $1,275,000 ($31.86 per share). Such dividend was paid on January 17, 2024 to the holders of record of our Series C Preferred Stock as of January 10, 2024.

Since November 1, 2022, we have been able to redeem the Series C Preferred Stock at any time, in whole or in part, for an amount based on the liquidation preference per share as in effect at such time. Holders of Series C Preferred Stock have the right to demand that we redeem their shares in the event that we undergo a change of control.

We believe that the completion of the Rights Offering will not limit the use of our NOLs due to any Section 382 limitations.

As the Company’s Board declared dividends on the Series C Preferred Stock as of December 31, 2023 and 2022, the liquidation value at both December 31, 2023 and 2022 was $1,062 per share. (See Note 13 to the Consolidated Financial Statements.)

Liquidity and Capital Resources

Our current source of liquidity is our existing cash on hand, which includes the approximately $43.6 million of gross proceeds from our Rights Offering and the interest earned on that amount. (See Note 13 to the Consolidated Financial Statements.) While we no longer have any research and development activities, we continue to retain rights to receive royalties and milestone payments from existing licensing arrangements with other companies and, accordingly, we may be entitled to a share of milestone and royalty payments from the approval and sale of Vicineum. We believe that our existing cash on hand will be sufficient to fund our operations, at least, through March 2025. Our future royalty revenues are expected to be de minimis in the future and we cannot assure you that we will receive any royalty, milestone or other revenues.

While we are positioned as a public company acquisition vehicle, where we can become an acquisition platform to potentially utilize our NOLs in an effort to enhance stockholder value, we cannot assure you that we will succeed in making acquisitions that are profitable or that we will be able to utilize any or all of our NOLs.

15

Table of Contents

Net cash used in operating activities represents income, as adjusted for certain non-cash items including the effect of changes in operating assets and liabilities. Net cash from operating activities during 2023 was $1,305,000, as compared to net cash used in operating activities of $659,000 in 2022. The increase in net cash provided of approximately $1,964,000 was primarily attributable to interest income of approximately $2,261,000 in 2023, resulting in net income of approximately $1,373,000 during that period compared to a net loss of approximately $186,000 during 2022.

Cash used in financing activities represents cash dividends of approximately $1,275,000 paid to holders of the Company’s Series C Preferred Stock during 2023. No cash was provided by financing activities in 2022. No cash was provided by investing activities in 2023 or 2022.

The net effect of the foregoing was a virtually unchanged cash position of approximately $47.0 million at December 31, 2023 and 2022.

Off-Balance Sheet Arrangements

We do not participate in transactions that generate relationships with unconsolidated entities or financial partnerships, such as entities often referred to as structured finance or special purpose entities, which would have been established for the purpose of facilitating off-balance sheet arrangements or other contractually narrow limited purposes. As of December 31, 2023, we were not involved in any off-balance sheet special purpose entity transactions.

Critical Accounting Policies and Estimates

A critical accounting policy is one that is both important to the portrayal of a company’s financial condition and results of operations and requires management’s most difficult, subjective or complex judgments, often as a result of the need to make estimates about the effect of matters that are inherently uncertain.

Our consolidated financial statements are presented in accordance with accounting principles that are generally accepted in the U.S. (“U.S. GAAP”). All applicable U.S. GAAP accounting standards effective as of December 31, 2023 have been taken into consideration in preparing the consolidated financial statements. The preparation of the consolidated financial statements requires estimates and assumptions that affect the reported amounts of assets, liabilities, revenues, expenses and related disclosures. Some of those estimates are subjective and complex, and, consequently, actual results could differ from those estimates. The following accounting policies and estimates have been highlighted as significant because changes to certain judgments and assumptions inherent in these policies could affect our consolidated financial statements.

We base our estimates, to the extent possible, on historical experience. Historical information is modified as appropriate based on current business factors and various assumptions that we believe are necessary to form a basis for making judgments about the carrying value of assets and liabilities. We evaluate our estimates on an ongoing basis and make changes when necessary. Actual results could differ from our estimates.

16

Table of Contents

Income Taxes

Under the asset and liability method of accounting for income taxes, deferred tax assets and liabilities are recognized for the estimated future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases and operating loss and tax credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. A valuation allowance on net deferred tax assets is provided for when it is more likely than not that some portion or all of the deferred tax assets will not be realized. As of December 31, 2023, we believe, based on our projections, that a partial reversal of the valuation allowance is necessary. Interest rates may fluctuate throughout 2024, however, they are not expected to return to low rates of the past creating a projected taxable income position. Therefore, the Company will partially reverse the valuation allowances. We are positioned as a public company acquisition vehicle, where we can become an acquisition platform and potentially utilize our NOLs. We may acquire businesses, entities or revenue streams that could generate sufficient income so that we can utilize our approximately $102.5 million of federal NOLs. At this time, however, we cannot assure you that we will be successful in doing so. Accordingly, our management will continue to assess the need for this valuation allowance and will make adjustments when appropriate. Additionally, our management believes that our NOLs will not be limited by any changes in our ownership as a result of the successful completion of the Rights Offering (See Note 13 to the Consolidated Financial Statements).

We recognize the benefit of an uncertain tax position that we have taken or expect to take on the income tax returns we file if it is more likely than not that we will be able to sustain our position.

Item 7A. Quantitative and Qualitative Disclosures About Market Risk

As a smaller reporting company, we are not required to provide the information required by this item.

Item 8. Financial Statements and Supplementary Data

Financial statements and notes thereto appear on pages F-1 to F-16 of this Annual Report on Form 10-K.

Item 9. Changes in and Disagreements with Accountants on Accounting and Financial Disclosure

None.

Item 9A. Controls and Procedures

(a)Evaluation of Disclosure Controls and Procedures

Our management, under the direction of our Principal Executive Officer and Principal Financial Officer, who is the same individual, has evaluated the effectiveness of our disclosure controls and procedures (as defined in Rules 13a-15(e) or 15d-15(e) under the Exchange Act of 1934, as amended (the “Exchange Act”), as of December 31, 2023. Disclosure controls and procedures are designed to ensure that information required to be disclosed in reports filed or submitted under the Exchange Act is recorded, processed, summarized and reported within the time periods specified in SEC rules and forms and that such information is accumulated and communicated to management, including the Principal Executive Officer and Principal Financial Officer, to allow timely decisions regarding required disclosures. Based on that evaluation, our Principal Executive Officer and Principal Financial Officer concluded that our disclosure controls and procedures were effective as of December 31, 2023.

(b)Changes in Internal Control Over Financial Reporting

There were no changes in our internal control over financial reporting, as such term is defined in Rules 13a-15(f) or 15d-15(f) under the Exchange Act, during the quarter ended December 31, 2023 that have materially affected, or are reasonably likely to materially affect, our internal control over financial reporting.

17

Table of Contents

(c)Management’s Report on Internal Control over Financial Reporting

It is the responsibility of the management of Enzon Pharmaceuticals, Inc. and subsidiaries to establish and maintain adequate internal control over financial reporting (as defined in Rule 13a-15(f) under the Exchange Act). Internal control over financial reporting is a process designed by, or under the supervision of, our Principal Executive Officer and Principal Financial Officer to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles, and includes those policies and procedures that: (i) pertain to the maintenance of records that, in reasonable detail, accurately and fairly reflect the transactions and dispositions of the assets of Enzon; (ii) provide reasonable assurance that transactions are recorded as necessary to permit preparation of consolidated financial statements in accordance with generally accepted accounting principles, and that receipts and expenditures of Enzon are being made only in accordance with authorizations of management and directors of Enzon; and (iii) provide reasonable assurance regarding the prevention or timely detection of unauthorized acquisition, use or disposition of Enzon’s assets that could have a material effect on the consolidated financial statements of Enzon.

Under the supervision and with the participation of our management, we conducted an evaluation of the effectiveness of our internal control over financial reporting based on criteria established in “Internal Control—Integrated Framework - 2013” issued by the Committee of Sponsoring Organizations of the Treadway Commission (COSO). Our management concluded that as of December 31, 2023 our internal control over financial reporting was effective based on those criteria.

(d)Limitations on the Effectiveness of Controls

Because of its inherent limitations, internal control over financial reporting may not prevent or detect misstatements. Therefore, even those systems determined to be effective can provide only reasonable assurance with respect to financial statement preparation and presentation.

​

18

Table of Contents

Item 9B. Other Information

During the quarter ended December 31, 2023, none of the Company’s directors or officers (as defined in Rule 16a-1(f) of the Exchange Act) adopted or terminated any contract, instruction or written plan for the purchase or sale of Company securities that was intended to satisfy the affirmative defense conditions of Rule 10b5-1(c) or any “non-Rule 10b5-1 trading arrangement”.

Item 9C. Disclosure Regarding Foreign Jurisdictions that Prevent Inspections

Not applicable.

​

PART III.

Item 10. Directors, Executive Officers and Corporate Governance

If we file a definitive proxy statement relating to our 2024 Annual Meeting of Stockholders with the SEC not later than 120 days after December 31, 2023, the information required by this Item 10 is incorporated herein by reference to such definitive proxy statement. However, if such definitive proxy statement is not filed with the SEC in such 120-day period, we will file an amendment to this Annual Report on Form 10-K with the SEC not later than 120 days after December 31, 2023 to include the information required by this Item 10.

The Company has adopted a code of ethics entitled “Code of Conduct and Corporate Values” that applies to the Company’s directors, officers, and employees (including its principal executive officer, principal financial officer, and principal accounting officer). We have posted our Code of Conduct and Corporate Values on our website (https://investors.enzon.com/corporate-governance) and will post on such website any amendments to, or waivers from, a provision of the Code of Conduct and Corporate Values applying to an executive officer or director when required by applicable SEC and OTC Markets rules and regulations.

​

Item 11. Executive Compensation

If we file a definitive proxy statement relating to our 2024 Annual Meeting of Stockholders with the SEC not later than 120 days after December 31, 2023, the information required by this Item 11 is incorporated herein by reference to such definitive proxy statement. However, if such definitive proxy statement is not filed with the SEC in such 120-day period, we will file an amendment to this Annual Report on Form 10-K with the SEC not later than 120 days after December 31, 2023 to include the information required by this Item 11.

Item 12. Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters

If we file a definitive proxy statement relating to our 2024 Annual Meeting of Stockholders with the SEC not later than 120 days after December 31, 2023, the information required by this Item 12 is incorporated herein by reference to such definitive proxy statement. However, if such definitive proxy statement is not filed with the SEC in such 120-day period, we will file an amendment to this Annual Report on Form 10-K with the SEC not later than 120 days after December 31, 2023 to include the information required by this Item 12.

Item 13. Certain Relationships and Related Transactions, and Director Independence

If we file a definitive proxy statement relating to our 2024 Annual Meeting of Stockholders with the SEC not later than 120 days after December 31, 2023, the information required by this Item 13 is incorporated herein by reference to such definitive proxy statement. However, if such definitive proxy statement is not filed with the SEC in such 120-day period, we will file an amendment to this Annual Report on Form 10-K with the SEC not later than 120 days after December 31, 2023 to include the information required by this Item 13.

19

Table of Contents

Item 14. Principal Accounting Fees and Services

If we file a definitive proxy statement relating to our 2024 Annual Meeting of Stockholders with the SEC not later than 120 days after December 31, 2023, the information required by this Item 14 is incorporated herein by reference to such definitive proxy statement. However, if such definitive proxy statement is not filed with the SEC in such 120-day period, we will file an amendment to this Annual Report on Form 10-K with the SEC not later than 120 days after December 31, 2023 to include the information required by this Item 14.

​

PART IV

Item 15. Exhibits, Financial Statement Schedules [TO BE DISCUSSED]

(a)(1), (a)(2) and (c). The response to this portion of Item 15 is submitted as a separate section of this report commencing on page F-1.

(a)(3) and (b). Exhibits (numbered in accordance with Item 601 of Regulation S-K).

20

Table of Contents

+Filed herewith

Referenced exhibit was previously filed with the SEC as an exhibit to the Company’s filing indicated below and is incorporated herein by reference to that filing:

(2)Annual Report on Form 10-K for the year ended December 31, 2012 filed March 18, 2013

(3)Annual Report on Form 10-K for the fiscal year ended June 30, 2002 filed on September 26, 2002

(4)Current Report on Form 8-K filed August 14, 2020

(5)Current Report on Form 8-K filed September 23, 2020

(6)Current Report on Form 8-K filed June 8, 2021

(7)Quarterly report on Form 10-Q for the quarter ended June 30, 2013 filed August 6, 2013

(8)Annual Report on Form 10-K for the fiscal year ended December 31, 2018 filed on February 21, 2019

(9)Current Report on Form 8-K filed September 1, 2020

(10)Annual Report on Form 10-K for the fiscal year ended December 31, 2021 filed on February 25, 2022

(11)Quarterly report on Form 10-Q for the quarter ended March 31, 2022 filed April 26, 2022

Item 16. Form 10-K Summary

None.

​

21

Table of Contents

SIGNATURES

Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

​

​

Pursuant to the requirements of the Securities Exchange Act of 1934, this report has been signed below by the following persons on behalf of the registrant and in the capacities and on the dates indicated.

​

​

​

22

Table of Contents

ENZON PHARMACEUTICALS, INC. AND SUBSIDIARIES

Index

​

​

F-1

Table of Contents

REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM [TO BE REVIEWED, ETC. BY EA]

To the Board of Directors and Stockholders of

Enzon Pharmaceuticals, Inc. and Subsidiaries

Opinion on the Financial Statements

We have audited the accompanying consolidated balance sheets of Enzon Pharmaceuticals, Inc. and Subsidiaries (the “Company”) as of December 31, 2023 and 2022, and the related consolidated statements of operations, mezzanine equity and stockholders’ equity, and cash flows for each of the years then ended and the related notes (collectively referred to as the “financial statements”). In our opinion, the financial statements present fairly, in all material respects, the financial position of the Company as of December 31, 2023 and 2022, and the results of their operations and their cash flows for each of the years then ended, in conformity with accounting principles generally accepted in the United States of America.

Basis for Opinion

These financial statements are the responsibility of the Company’s management. Our responsibility is to express an opinion on the Company’s financial statements based on our audits. We are a public accounting firm registered with the Public Company Accounting Oversight Board (United States) (“PCAOB”) and are required to be independent with respect to the Company in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.

We conducted our audits in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement, whether due to error or fraud. The Company is not required to have, nor were we engaged to perform, an audit of its internal control over financial reporting. As part of our audits, we are required to obtain an understanding of internal control over financial reporting but not for the purpose of expressing an opinion on the effectiveness of the Company’s internal control over financial reporting. Accordingly, we express no such opinion.

Our audits included performing procedures to assess the risks of material misstatement of the financial statements, whether due to error or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the financial statements. Our audits also included evaluating the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the financial statements. We believe that our audits provide a reasonable basis for our opinion.

Critical Audit Matter

The critical audit matter communicated below is a matter arising from the current period audit of the financial statements that was communicated or required to be communicated to the audit committee and that: (1) relates to accounts or disclosures that are material to the financial statements and (2) involved our especially challenging, subjective, or complex judgments. The communication of the critical audit matter does not alter in any way our opinion on the financial statements, taken as a whole, and we are not, by communicating the critical audit matter below, providing a separate opinion on the critical audit matter or on the accounts or disclosures to which it relates.

As discussed in Note 9 to the consolidated financial statements, the Company records a valuation allowance based on the assessment of the realizability of the Company’s deferred tax assets. For the year-ended December 31, 2023, the Company had deferred tax assets before valuation allowances of approximately $34.4 million. As of December 31, 2023, the Company has recorded a valuation allowance of approximately $34.1 million on the deferred tax assets, resulting in a deferred tax asset of $359,000 as of December 31, 2023. In assessing the realizability of deferred tax assets the Company must assess its tax planning strategies, enacted and effective tax law considerations, and whether sufficient future taxable income will be generated to support the realization of the existing deferred tax assets before expiration, using assumptions about Company-specific conditions and events.

We identified the assessment of realizability of deferred tax assets as a critical audit matter due to the significant judgement and estimation required by management in their assessment. This in turn led to a high degree of auditor subjectivity and significant audit effort was required in performing our procedures and evaluating audit evidence relating to estimates and assumptions made by management.

F-2

Table of Contents

Addressing the matter involved performing procedures and evaluating audit evidence, in connection with forming our overall opinion on the consolidated financial statements. We obtained an understanding and evaluated the design of controls over the valuation of deferred taxes. Our procedures also included, among others, an evaluation of: (a) the expiration dates of certain deferred tax assets, primarily federal and state net operating loss carryforwards, (b) whether the Company may have experienced an ownership change resulting in annual limitation of net operating loss carryforwards, and (c) the assumptions used by the Company to develop projections of future taxable income by income tax jurisdiction and tested the completeness and accuracy of the underlying data used in the projections. We compared the projections of future taxable income with the actual results of prior periods, as well as management’s consideration of current industry and economic trends. We also compared the projections of future taxable income with other forecasted financial information prepared by the Company. These procedures also included, among others, the involvement of professionals with specialized skill and knowledge to assist in considering whether management demonstrated their ability and intent in executing planned strategies, including the reasonableness of the application of enacted and effective tax law.

/s/ EisnerAmper LLP

We have served as the Company’s auditor since 2013.

EISNERAMPER LLP

Philadelphia, Pennsylvania

March 20, 2024

F-3

Table of Contents

ENZON PHARMACEUTICALS, INC. AND SUBSIDIARIES

CONSOLIDATED BALANCE SHEETS

(In thousands, except share and per share amounts)

​

​

The accompanying notes are an integral part of these consolidated financial statements.

​

F-4

Table of Contents

ENZON PHARMACEUTICALS, INC. AND SUBSIDIARIES

CONSOLIDATED STATEMENTS OF OPERATIONS

(In thousands, except per share amounts)

​

​

The accompanying notes are an integral part of these consolidated financial statements.

​

F-5

Table of Contents

ENZON PHARMACEUTICALS, INC. AND SUBSIDIARIES

CONSOLIDATED STATEMENTS OF MEZZANINE EQUITY AND STOCKHOLDERS’ EQUITY

(In thousands)

​

​

The accompanying notes are an integral part of these consolidated financial statements.

​

F-6

Table of Contents

ENZON PHARMACEUTICALS, INC. AND SUBSIDIARIES

CONSOLIDATED STATEMENTS OF CASH FLOWS

(In thousands)

​

​

The accompanying notes are an integral part of these consolidated financial statements.

​

​

F-7

Table of Contents

ENZON PHARMACEUTICALS, INC. AND SUBSIDIARIES

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

F-8

Table of Contents

ENZON PHARMACEUTICALS, INC. AND SUBSIDIARIES

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

​

​

F-9

Table of Contents

ENZON PHARMACEUTICALS, INC. AND SUBSIDIARIES

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

​

​

​

​

​

F-10

Table of Contents

ENZON PHARMACEUTICALS, INC. AND SUBSIDIARIES

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

​

​

​

F-11

Table of Contents

ENZON PHARMACEUTICALS, INC. AND SUBSIDIARIES

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

​

F-12

Table of Contents

ENZON PHARMACEUTICALS, INC. AND SUBSIDIARIES

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

​

​

​

F-13

Table of Contents

ENZON PHARMACEUTICALS, INC. AND SUBSIDIARIES

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

​

​

​

F-14

Table of Contents

ENZON PHARMACEUTICALS, INC. AND SUBSIDIARIES

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

​

​

​

​

​

F-15