Form 10-Q - Quarterly report [Sections 13 or 15(d)]

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 10-Q

(Mark One)


☒	QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the quarterly period ended March 31, 2024


☐	TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the transition period from to

Commission file number 001-36435

Enzon Pharmaceuticals, Inc.

(Exact name of registrant as specified in its charter)


Delaware	22-2372868
(State of incorporation)	(I.R.S. Employer Identification No.)

20 Commerce Drive (Suite 135), Cranford, New Jersey	07016
(Address of principal executive offices)	(Zip Code)

(732) 980-4500

(Registrant’s telephone number, including area code)

Not Applicable

(Former name, former address and former fiscal year, if changed since last report)

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

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 (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities 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.


Large accelerated filer ☐	Accelerated filer ☐
Non-accelerated filer ☒	Smaller reporting company ☒
	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. ☐

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

Shares of Common Stock outstanding as of May 3, 2024: 74,214,603

Table of Contents

ENZON PHARMACEUTICALS, INC.

Table of Contents


		Page
	PART I - FINANCIAL INFORMATION	3
Item 1.	Financial Statements	3
Item 2.	Management’s Discussion and Analysis of Financial Condition and Results of Operations	14
Item 3.	Quantitative and Qualitative Disclosures About Market Risk	18
Item 4.	Controls and Procedures	18

	PART II – OTHER INFORMATION	19

Item 1.	Legal Proceedings	19
Item 1A.	Risk Factors	19
Item 2.	Unregistered Sales of Equity Securities and Use of Proceeds	19
Item 3.	Defaults Upon Senior Securities	19
Item 4.	Mine Safety Disclosures	19
Item 5.	Other Information	19
Item 6.	Exhibits	19
Signatures		20

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PART I – FINANCIAL INFORMATION

Item 1. Financial Statements.

ENZON PHARMACEUTICALS, INC. AND SUBSIDIARIES

CONDENSED CONSOLIDATED BALANCE SHEETS

(In thousands, except share and per share amounts)


	March 31,		December 31,
	2024		2023
	(Unaudited)
ASSETS

Current assets:
Cash and cash equivalents	$	45,988	$	47,012
Other current assets		481		331
Total current assets		46,469		47,343
Deferred tax asset		360		359

Total assets	$	46,829	$	47,702

LIABILITIES AND STOCKHOLDERS’ EQUITY

Current liabilities:
Accounts payable	$	331	$	331
Accrued expenses and other current liabilities		190		108
Dividends payable on Series C preferred stock		—		1,275
Total current liabilities		521		1,714

Commitments and contingencies

Mezzanine equity:
Series C preferred stock - $0.01 par value, 40,000 shares authorized, issued and outstanding (liquidation value $1,075 and $1,062 per share) at March 31, 2024 and December 31, 2023		43,014		42,483

Stockholders’ equity:
Preferred stock - $0.01 par value, authorized 2,960,000 shares; no shares issued and outstanding at March 31, 2024 and December 31, 2023		—		—
Common stock - $0.01 par value, authorized 170,000,000 shares; issued and outstanding 74,214,603 shares at March 31, 2024 and December 31, 2023		742		742
Additional paid-in capital		72,902		73,433
Accumulated deficit		(70,350)		(70,670)
Total stockholders’ equity		3,294		3,505
Total liabilities, mezzanine equity and stockholders’ equity	$	46,829	$	47,702

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

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ENZON PHARMACEUTICALS, INC. AND SUBSIDIARIES

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS

(In thousands, except per share amounts)

(Unaudited)


	Three months ended
	March 31,
	2024		2023
Revenues:
Royalties and milestones, net	$	—	$	—
Total revenues		—		—

Operating expenses:
General and administrative		326		285
Total operating expenses		326		285

Operating loss		(326)		(285)
Interest and dividend income		647		447

Income before income tax benefit		321		162

Income tax (expense) benefit		(1)		35

Net income		320		197
Dividends on Series C preferred stock		(531)		(531)
Net loss available to common shareholders	$	(211)	$	(334)

Loss per common share
Basic and diluted	$	(0.00)	$	(0.00)

Weighted average number of common shares
Basic and diluted		74,215		74,215

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

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ENZON PHARMACEUTICALS, INC. AND SUBSIDIARIES

CONDENSED CONSOLIDATED STATEMENTS OF MEZZANINE EQUITY AND STOCKHOLDERS’ EQUITY

(In thousands)

(Unaudited)


	Mezzanine Equity – Series C
	Preferred Stock			Common Stock			Additional				Total
	Number of	Par		Number of	Par		Paid-in		Accumulated		Stockholders’
	Shares	Value		Shares	Value		Capital		Deficit		Equity
Balance, December 31, 2022	40		42,483	74,215	$	742	$	74,708	$	(72,043)	$	3,407
Net income	—		—	—		—		—		197		197
Preferred stock dividend accumulation	—		531	—		—		(531)		—		(531)
Balance, March 31, 2023	40	$	43,014	74,215	$	742	$	74,177	$	(71,846)	$	3,073


	Mezzanine Equity – Series C
	Preferred Stock			Common Stock			Additional				Total
	Number of	Par		Number of	Par		Paid-in		Accumulated		Stockholders’
	Shares	Value		Shares	Value		Capital		Deficit		Equity
Balance, December 31, 2023	40		42,483	74,215	$	742	$	73,433	$	(70,670)	$	3,505
Net income	—		—	—		—		—		320		320
Preferred stock dividend accumulation	—		531	—		—		(531)		—		(531)
Balance, March 31, 2024	40	$	43,014	74,215	$	742	$	72,902	$	(70,350)	$	3,294

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

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ENZON PHARMACEUTICALS, INC. AND SUBSIDIARIES

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS

(In thousands)

(Unaudited)


	Three months ended
	March 31,
	2024		2023
Cash flows from operating activities:
Net income	$	320	$	197
Adjustments to reconcile net income to net cash provided by operating activities:
Deferred income taxes		(1)		(36)
Changes in operating assets and liabilities		(68)		9
Net cash provided by operating activities		251		170

Cash flows from financing activities:
Preferred stock dividend payments		(1,275)		(1,275)
Net cash used in financing activities		(1,275)		(1,275)

Net decrease in cash and cash equivalents		(1,024)		(1,105)

Cash and cash equivalents, beginning of period		47,012		46,982

Cash and cash equivalents, end of period	$	45,988	$	45,877

Non-cash financing activities:
Accretion of dividend for Series C Preferred Stock	$	531	$	531

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

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ENZON PHARMACEUTICALS, INC. AND SUBSIDIARIES

NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS

(1)Description of Business

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

In September 2020, the Company initiated a rights offering for its common and preferred stock (see below and Note 12 to our Condensed Consolidated Financial Statements), which closed in October 2020, and it realized $43.6 million in gross proceeds. This has enabled the Company to embark on its plan to potentially realize the value of its more than $100 million NOLs by acquiring businesses or assets. To protect the NOLs, in August 2020, the Company’s Board of Directors (the “Board”) adopted a Section 382 rights plan (see Note 11 to our Condensed Consolidated Financial Statements).

Historically, the Company had 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, the Company has had no clinical operations and limited corporate operations. Enzon has a marketing agreement in the drug Vicineum, which, if approved, would, potentially, generate milestone and royalty payments to it in the future. Enzon cannot assure you that it will earn material future royalties or milestones.

The Board and the Company’s management are actively involved in pursuing, sourcing, reviewing and evaluating various potential acquisition transactions consistent with its strategy. The Company’s management and Board have made a number of contacts and engaged in discussions with principals of individual companies and financial advisors on behalf of various individual companies, while continuing to evaluate potential transactions. To date, no acquisition candidates have been identified that are in an actionable state.

The Company has a marketing agreement with Micromet AG, now part of Amgen, Inc. (the “Micromet Agreement”), pursuant to which it 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 it intends to seek a partner for the further development of Vicineum.

In the past, through 2022, the Company received an annual license maintenance fee of approximately $26,000 from Amgen, Inc. in payment of a worldwide, royalty-free non-exclusive right to license Vicineum. The fee represents half of the amount paid by Viventia Biotech (Barbados) Inc. (“Viventia”), part of Sesen, on an annual basis for the continued right to license Vicineum. The Company did not receive any license maintenance fees in 2023 or through the first quarter of 2024.

In August 2020, the Board 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. (See Note 11 to the Consolidated Financial Statements.)

In September 2020, the Board approved a Rights Offering (the “Rights Offering”), by which the Company distributed, at no charge to all holders of its common stock on September 23, 2020 (the “Record Date”), transferable subscription rights to purchase units (“Units”) at a subscription price per Unit of $1,090. In the Rights Offering, each stockholder on the Record Date received one subscription right for every share of common stock owned on the Record Date. For every 1,105 subscription rights held, a stockholder was entitled to purchase one Unit at the subscription price. Each Unit consisted of one share of newly designated Series C Preferred Stock, par value $0.01 per share, and 750 shares of the Company’s common stock. The subscription period for the Rights Offering ended on October 9, 2020.

As a result of the sale of all 40,000 Units available for purchase in the Rights Offering, the Company received approximately $43.6 million of gross proceeds and had 40,000 shares of Series C Preferred Stock outstanding and an aggregate of 74,214,603 shares of common stock outstanding following the Rights Offering. (See Note 12 to the Consolidated Financial Statements.)

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ENZON PHARMACEUTICALS, INC. AND SUBSIDIARIES

NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS

(1)Description of Business (continued)

On an annual basis, the 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 (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. The Board did not declare a dividend as of December 31, 2021 and, at December 31, 2021 the liquidation value of the Series C Preferred Stock was $1,062 per share. On December 29, 2022, the Board declared a cash dividend of 3% on the Series C Preferred Stock, aggregating $1,275,000 or $31.86 per share. Accordingly, the cumulative liquidation value of the Series C Preferred Stock remained at approximately $42,483,000 ($1,062 per share) on December 31, 2022. On December 28, 2023, the Board declared a cash dividend of 3% on the Series C Preferred Stock, aggregating approximately $1,275,000 or $31.86 per share. Accordingly, the cumulative liquidation value of the Series C Preferred Stock remained at approximately $42,483,000 ($1,062 per share) on December 31, 2023. The dividend was paid on January 17, 2024 to the holders of record of the Company’s Series C Preferred Stock as of January 10, 2024. (See Note 13 to the Consolidated Financial Statements.)

As of March 31, 2024, the Board had not yet determined whether to declare a cash dividend at the end of 2024. Accordingly, the Company accrued an accretion at 5% for the quarter on a pro rata basis (approximately $531,000 or $13 per share) and, as a result, the liquidation value of the Series C Preferred Stock was approximately $43,014,000 ($1,075 per share) at March 31, 2024. (See Note 13 to the Condensed Consolidated Financial Statements.)

The Company maintains its principal executive offices at 20 Commerce Drive, Suite 135, Cranford, New Jersey 07016 through a service agreement with Regus Management Group, LLC.

(2)Basis of Presentation

Interim Financial Statements

The accompanying unaudited condensed consolidated financial statements have been prepared from the books and records of the Company in accordance with United States accounting principles generally accepted in the United States of America (“U.S. GAAP”) for interim financial information and Rule 10-01 of Regulation S-X promulgated by the Securities and Exchange Commission (“SEC”). Accordingly, these financial statements do not include all of the information and footnotes required for complete annual financial statements. Interim results are not necessarily indicative of the results that may be expected for the full year. Interim condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and the notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2023.

Principles of Consolidation

The condensed consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. All intercompany balances and transactions have been eliminated as part of the consolidation.

Use of Estimates

The preparation of consolidated financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect reported amounts of assets and liabilities, disclosures of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenues and expenses during the reporting period. These estimates include legal and contractual contingencies and income taxes. Although management bases its estimates on historical experience, relevant current information and various other assumptions that are believed to be reasonable under the circumstances, actual results could differ from these estimates.

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ENZON PHARMACEUTICALS, INC. AND SUBSIDIARIES

NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS

(2)Basis of Presentation (continued)

Revenue Recognition

Royalty revenues from the Company’s agreements with third parties and pursuant to the sale of the Company’s former specialty pharmaceutical business are recognized when the Company can reasonably determine the amounts earned. In most cases, this will be upon notification from the third-party licensee, which is typically during the quarter following the quarter in which the sales occurred. The Company does not participate in the selling or marketing of products for which it receives royalties. Because the Company records revenue only when collection is assured, no provision for uncollectible accounts is established upon recognition of revenues.

Contingent payments with third parties and pursuant to the sale of the Company’s former specialty pharmaceutical business are recognized as income when the milestone has been achieved and collection is assured, such payments are non-refundable and no further effort is required on the part of the Company or the other party to complete the earning process.

Income Taxes

Income taxes are accounted for under the asset and liability method. 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 realized. The effect of a change in tax rates or laws on deferred tax assets and liabilities is recognized in operations in the period that includes the enactment date of the rate change. A valuation allowance is established to reduce the deferred tax assets to the amounts that are more likely than not to be realized from operations.

Tax benefits of uncertain tax positions are recognized only if it is more likely than not that the Company will be able to sustain a position taken on an income tax return. The Company has no liability for uncertain tax positions. Interest and penalties, if any, related to unrecognized tax benefits, would be recognized as income tax expense.

(3)Recent Accounting Pronouncements

Recent Accounting Standards Updates issued by the Financial Accounting Standards Board (the “FASB”) and guidance issued by the SEC did not, or are not believed by management to, have a material effect on the Company’s present or future consolidated financial statements.

(4)Financial Instruments and Fair Value

The carrying values of cash and cash equivalents, other current assets, accounts payable, accrued expenses and other current liabilities in the Company’s consolidated balance sheets approximated their fair values at March 31, 2024 and December 31, 2023 due to their short-term nature. As of each of March 31, 2024 and December 31, 2023, the Company held cash equivalents aggregating approximately $45.9 million and $47.0 million, respectively.

(5)Supplemental Cash Flow Information

The Company made no income tax payments during each of the three-month periods ended March 31, 2024 and 2023. There were no interest payments made during either of the three-month periods ended March 31, 2024 or 2023.

(6)Cash Dividend

On December 28, 2023, the Board declared a cash dividend of 3% on the Series C Preferred Stock, aggregating approximately $1,275,000 or $31.86 per share. Accordingly, the cumulative liquidation value of the Series C Preferred Stock was approximately $42,483,000 ($1,062 per share) on December 31, 2023. The dividend was paid on January 17, 2024 to the holders of record of the Company’s Series C Preferred Stock as of January 10, 2024 (See Note 13 to the Consolidated Financial Statements).

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ENZON PHARMACEUTICALS, INC. AND SUBSIDIARIES

NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS

(6)Cash Dividend (continued)

On December 29, 2022, the Board declared a cash dividend of 3% on the Series C Preferred Stock, aggregating approximately $1,275,000 or $31.86 per share. Accordingly, the cumulative liquidation value of the Series C Preferred Stock was approximately $42,483,000 ($1,062 per share) on December 31, 2022. The dividend was paid on January 17, 2023 to the holders of record of the Company’s Series C Preferred Stock as of January 10, 2023 (See Note 13 to the Condensed Consolidated Financial Statements).

(7)Loss Per Common Share

Basic earnings (loss) per common share (EPS) is calculated by dividing net income (loss), less any dividends, accretion or reduction or redemption on the Company’s Series C Preferred Stock, by the weighted average number of common shares outstanding during the reported period. Restricted stock awards and restricted stock units (collectively, “nonvested shares”) are not considered to be outstanding shares until the service or performance vesting period has been completed.

The diluted earnings per common share calculation would normally involve adjusting both the denominator and numerator as described here if the effect is dilutive.

For purposes of calculating diluted earnings per common share, the denominator normally includes both the weighted-average number of shares of common stock outstanding and the number of common stock equivalents if the inclusion of such common stock equivalents is dilutive. Dilutive common stock equivalents potentially include stock options and nonvested shares using the treasury stock method and shares issuable under the employee stock purchase plan. During each of the quarters ended March 31, 2024 and 2023, there were no common stock equivalents. There were no stock options or other equity-based incentives outstanding in either such period. Loss per common share information is as follows (in thousands, except per share amounts) for the three months ended March 31, 2024 and 2023:


	Three months ended
	March 31,
	2024		2023
Loss Per Common Share – Basic and Diluted:
Net income	$	320	$	197
Dividends on Series C preferred stock		(531)		(531)
Net loss available to common shareholders	$	(211)	$	(334)

Weighted-average common shares outstanding		74,215		74,215

Basic and diluted loss per share	$	(0.00)	$	(0.00)

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ENZON PHARMACEUTICALS, INC. AND SUBSIDIARIES

NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS

(8)Income Taxes

During the three-month period ended March 31, 2024 the Company recorded approximately $500 of income tax expense. During the comparable period in 2023, the Company recorded $34,500 of income tax benefit. The income tax benefit in the 2023 period was mainly related to a partial reversal of the valuation allowance on its deferred tax assets.

ASC 740 requires the reduction of deferred tax assets by a valuation allowance if, based on the weight of available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized. Because of the inherent uncertainties, including future interest rates, whether or when an acquisition of a profitable entity will come to fruition and other factors, projecting long-term future performance of the Company is problematical. Accordingly, the Company is only projecting pre-tax book income through March 31, 2025 due to interest rates on its short-term cash investments and the absence of any potentially actionable 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 the period through March 31, 2025. However, the Company does not expect them to return to low rates of the past creating a projected taxable income position. Accordingly, a deferred tax benefit of $1,000 and $36,000 was recorded during the quarters ended March 31, 2024 and 2023, respectively. The Company may acquire businesses, entities or revenue streams that could generate sufficient income so that it can utilize its approximately $102.2 million NOL. To date, no acquisition candidates have been identified that are in an actionable state and, while the Company may ultimately be successful in realizing some or all of the value of its NOLs, the Company cannot provide assurance that it will be able to realize any value of its NOLs.

Management of the Company will continue to assess the need for this valuation allowance and will make adjustments when or if appropriate.

At March 31, 2024, the Company had federal NOLs of approximately $102.2 million, of which approximately $99.1 million will expire in the years 2025 through 2036, and New Jersey state NOLs of approximately $24.5 million that expire in the years 2031 through 2042. Under the Tax Cuts and Jobs Act, net operating losses generated in tax years beginning after December 31, 2017 have an unlimited carryforward period, and the amount of net operating loss allowed to be utilized each year is limited to 80% of taxable income.

At March 31, 2024, the Company has federal research and development (“R&D”) credit carryforwards of approximately $9.4 million that expire in the years 2024 through 2029. These deferred tax assets were subject to a valuation allowance such that the deferred tax expense incurred as a result of the expiration of the R&D credit carryforwards was offset by a corresponding deferred tax benefit for the related reduction in valuation allowance.

The Company's ability to use the NOLs and R&D tax credit carryforwards may be limited, as they are subject to certain limitations due to ownership changes as defined by rules pursuant to Section 382 of the Internal Revenue Code of 1986, as amended. However, management of the Company believes that the Company's 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 12 to the Consolidated Financial Statements.) Additionally, in an effort to protect stockholder value by attempting to protect against a possible limitation on the Company's ability to use its NOLs, the Board adopted a Section 382 rights plan. (See Note 11 to the Consolidated Financial Statements.)

The Company has not recorded a liability for unrecognized income tax benefits.

(9)Commitments and Contingent Liabilities

On January 17, 2024, the Company was notified by the OTCQX Markets Group (the “OTCQX”), the marketplace for the over-the-counter trading of its stock, that it no longer met the standards for continued qualification for the OTCQX, in that its stock bid price had fallen below $0.10 per share for 30 consecutive calendar days. To regain compliance, the Company must maintain a closing bid price of at least $0.10 for 10 consecutive trading days before July 15, 2024.

The Company has been involved in various claims and legal actions arising in the ordinary course of business. In the opinion of management, the ultimate disposition of these matters will not have a material effect on the Company’s consolidated financial position, results of operations, or liquidity.

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ENZON PHARMACEUTICALS, INC. AND SUBSIDIARIES

NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS

(10)Accounts Payable and Accrued Expenses

Prior to 2017, the Company’s primary source of royalty revenues was derived from sales of PegIntron, which is marketed by Merck & Co., Inc. (“Merck”). At December 31, 2023, we recorded a liability to Merck of approximately $331,000, based primarily on Merck’s assertions regarding recoupments related to prior returns and rebates. Merck has not yet reported royalty revenues earned by us for product sales and/or recoupments for returns and rebates for the quarter ended March 31, 2024. Accordingly, at March 31, 2024, the Company recorded a net payable to Merck of approximately $331,000 due to such royalty overpayment claims by Merck. The Company believes that it will receive no additional royalties from Merck.

Accrued expenses and other current liabilities consisted of the following as of March 31, 2024 and 2023 (in thousands):


	March 31,		December 31,
	2024		2023
Professional and consulting fees	$	184	$	92
Other		6		16
	$	190	$	108

(11)Section 382 Rights Plan

On August 14, 2020, in an effort to protect stockholder value by attempting to protect against a possible limitation on the Company’s ability to use its NOLs, the Board 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 the Company one one-thousandth of a share of the Company’s 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), (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 or (iv) the close of business on the first day of a taxable year of the Company to which the Company’s Board of Directors determines that no NOLs may be carried forward.

(12)Rights Offering

On September 1, 2020, the Board approved a Rights Offering. For every 1,105 subscription rights held, a stockholder was entitled to purchase one Unit at the subscription price of $1,090. Each Unit consisted of one share of newly designated Series C Preferred Stock, par value $0.01 per share, and 750 shares of the Company’s common stock. On October 9, 2020, the Rights Offering expired and, as a result of the sale of all 40,000 Units, the Company received approximately $43.6 million in gross proceeds and issued shares of Series C Preferred Stock and shares of common stock such that, following the closing of the Rights Offering, there was an aggregate of 40,000 shares of Series C Preferred Stock outstanding and 74,214,603 shares of common stock outstanding.

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ENZON PHARMACEUTICALS, INC. AND SUBSIDIARIES

NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS

(12)Rights Offering (continued)

On an annual basis, the 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 (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 the Company’s common stock. The initial liquidation value of the Series C Preferred Stock was $1,000 per share. At December 31, 2021 the liquidation value of the Series C Preferred Stock was $1,062 per share, inasmuch as no dividend was declared or paid in cash. On December 29, 2022, the Board declared a cash dividend of 3% on the Series C Preferred Stock, aggregating approximately $1,275,000 or $31.86 per share. Accordingly, the liquidation value of the Series C Preferred Stock was $1,062 per share on December 31, 2022. The dividend was paid on January 17, 2023 to the holders of record of the Company’s Series C Preferred Stock as of January 10, 2023. On December 28, 2023, the Board declared a cash dividend of 3% on the Series C Preferred Stock, aggregating approximately $1,275,000 or $31.86 per share. Accordingly, the liquidation value of the Series C Preferred Stock remained at $1,062 per share on December 31, 2023. The dividend was paid on January 17, 2024 to the holders of record of the Company’s Series C Preferred Stock as of January 10, 2024.

Since November 1, 2022, the Company is 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 the Company redeem their shares in the event that the Company undergoes a change of control as defined in the Certificate of Designation of the Series C Preferred Stock.

(13)Series C Preferred Stock

In October 2020, the Company issued 40,000 shares of Series C Preferred Stock for an aggregate purchase price of $40.0 million.

As of December 31, 2021, the Board had not declared a cash dividend on the Series C Preferred Stock. Accordingly, during the year ended December 31, 2021, the Company recorded a 5% increase to the liquidation preference of approximately $50 per share of Series C Preferred Stock, aggregating approximately $2,023,000, for a cumulative liquidation value of approximately $42,483,000 ($1,062 per share) as of December 31, 2021. Because a cash dividend of 3% was declared for each of 2023 and 2022, at December 31, 2023 and 2022 there was no change to the liquidation value that was recorded as of December 31, 2021.

There is no prohibition on the repurchase or redemption of Series C Preferred Shares while there is any arrearage in the payment of dividends.

Since the redemption of the Series C Preferred Stock is contingently or optionally redeemable, unless and until we undertake a change of control the Series C Preferred Stock has been classified in mezzanine equity on the Consolidated Balance Sheets.

(14) Cash and Cash Equivalents

The Company defines cash equivalents as highly liquid, short-term investments with original maturities of three months or less. These financial instruments potentially subject the Company to concentrations of credit risk. The Company maintains deposit accounts with several financial institutions. These balances are partially insured by the Federal Deposit Insurance Corporation (“FDIC”) up to $250,000 per depositor, per FDIC-insured bank, per ownership category. Such deposits may exceed FDIC insurance limits. Although the Company currently believes that the financial institutions with whom it does business will be able to fulfill their commitments to the Company, there is no assurance that those institutions will be able to continue to do so. The Company has not experienced any credit losses associated with its balances in such accounts for the three-month periods ended March 31, 2024 and 2023 and the year ended December 31, 2023.

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Item 2. Management’s Discussion and Analysis of Financial Condition and Results of Operations.

Unless the context requires otherwise, references in this Quarterly Report on Form 10-Q to “Enzon,” the “Company,” “we,” “us,” or “our” and similar terms mean Enzon Pharmaceuticals, Inc. and its subsidiaries. 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 Quarterly Report on Form 10-Q and our 2023 Annual Report on Form 10-K.

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,” “potential,” “anticipates,” “plans,” 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 known and unknown 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 in our 2023 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. As such, no assurance can be given 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 and not the rounded millions of dollars reflected in this section.

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 $102.2 million of federal NOLs. To date, no acquisition candidates have been identified that are in an actionable state and, while we may 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 year ended December 31, 2023 and the quarters ended March 31, 2024 and 2023.

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 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.

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.

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Acquisition Activities

Our Board of Directors and our management are actively involved in pursuing, sourcing, reviewing and evaluating various potential acquisition transactions consistent with our long-term strategy. Our management and Board of Directors have made a number of contacts and engaged in discussions with principals of individual companies and financial advisors on behalf of various individual companies, while continuing to evaluate potential transactions. To date, we have not developed any actionable transactions. We will continue to update our stockholders as material developments arise.

Throughout this Management’s Discussion and Analysis, the primary focus is on our results of operations, cash flows and financial condition. The percentage changes throughout the following discussion are based on amounts stated in thousands of dollars.

Results of Operations

Revenues:

In the three months ended March 31, 2024 and 2023, we earned no milestone or royalty revenues.

Interest and Dividend Income (in thousands of dollars):


	Three Months Ended March 31,
			%
	2024		Change	2023
Interest and dividend income	$	647	45	$	447

Interest and dividend income is attributable to the interest and dividends received on the invested cash and cash equivalents we received from the $43.6 million of proceeds from our rights offering (see Note 12 to our Consolidated Financial Statements). Interest and dividend income increased by approximately $200,000, or 45%, to $647,000 for the first quarter of 2024 from $447,000 for the comparable period in 2023. The increase in other income is attributable to the higher rates of interest in the first quarter of 2024 compared to 2023.

Operating Expenses:

General and Administrative (in thousands of dollars):


	Three Months Ended March 31,
			Percent
	2024		Change		2023
General and administrative	$	326	14	%	$	285

General and administrative expenses increased by approximately $41,000, or 14%, to approximately $326,000 for the first quarter of 2024 from approximately $285,000 for the first quarter of 2023. The increase in general and administrative expense is substantially attributable to the increase in professional fees.

Tax Expense:

Assuming no acquisition is completed or material changes in results through March 2025, the Company has partially reversed the valuation allowances as of March 31, 2024. Deferred tax benefits of $1,000 and $36,000, respectively were recorded during the quarters ended March 31, 2024 and 2023. (See Note 8 to the Condensed 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 12 to the Condensed 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 April 2025. Our future royalty revenues are expected to be de minimis over the next several years and we cannot assure you that we will receive any royalty, milestone or other revenues.

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While we are positioned as a public company acquisition vehicle, where we can become an acquisition platform and more fully utilize our NOLs and enhance stockholder value, we cannot assure you that we will succeed in making acquisitions that are profitable and that will enable us to utilize our NOLs.

Cash provided by operating activities represents a net income, as adjusted for certain non-cash items including the effect of changes in operating assets and liabilities. Cash provided by operating activities during the three months ended March 31, 2024 was approximately $251,000, as compared to cash provided by operating activities of approximately $170,000 during the comparable period in 2023. The increase of approximately $81,000 was primarily attributable to interest income of approximately $647,000 in the first quarter of 2024, resulting in net income of approximately $320,000 during that quarter compared to net income of approximately $197,000 during the first quarter of 2023.

Cash used in financing activities represents cash dividends of approximately $1,275,000 paid to holders of the Company’s Series C Preferred Stock.

The net effect of the foregoing was a decrease of cash and cash equivalents of approximately $1.0 million, from $47.0 million at December 31, 2023 to $46.0 million at March 31, 2024.

Off-Balance Sheet Arrangements

As part of our ongoing business, 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 (SPEs), which would have been established for the purpose of facilitating off-balance sheet arrangements or other contractually limited purposes. As of March 31, 2024, we were not involved in any SPE 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 March 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.

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 March 31, 2024, we believe, based on our projections, that a partial reversal of the valuation allowance is necessary. Interest rates may fluctuate throughout 2024 and during the first quarter of 2025, 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 $102.2 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

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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 12 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.

Forward-Looking Information and Factors That May Affect Future Results

This Quarterly Report on Form 10-Q contains forward-looking statements within the “safe harbor” provisions of the Private Securities Litigation Reform Act of 1995. All statements contained in the Quarterly Report on Form 10-Q, 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 the words “believes,” “expects,” “may,” “will,” “should,” “potential,” “anticipates,” “plans” 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 known and unknown risks and uncertainties that could cause actual results, events or developments to be materially different from those indicated in such forward-looking statements, including, but not limited to, the following risks and uncertainties:

We may be unsuccessful in our strategy to fully utilize our NOLs and other tax assets and enhance stockholder value as a public company acquisition vehicle.

●

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.

●

In recent years, we derived most of our royalty revenues from continued sales of PegIntron, which have been in sharp decline. In addition, our right to receive royalties on U.S. and European sales of PegIntron expired in 2016 and 2018, respectively, which has negatively impacted our royalty revenues.

●

Our rights to receive royalties on sales of PegIntron and sales of other drug products have expired in various jurisdictions and, except for Vicineum, will, by 2024, expire world-wide. We currently do not anticipate any significant royalties from other sources, but we may acquire new sources of royalty revenues.

●

The unprecedented actions taken globally to control the spread of COVID 19 and its related variants, as well as the uncertainty surrounding the success of global vaccination efforts, may materially and adversely affect our future right to receive licensing fees, milestone payments and royalties on product candidates that are being developed by third parties.

●

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

●

We may be subject to a variety of types of product liability or other claims based on allegations that the use of our product candidates by participants in our previously conducted clinical trials has resulted in adverse effects, and our insurance may not cover all product liability or other claims.

●

Our revenues largely depend on proprietary rights, which may offer only limited protection against the development of competing products.

●

We are party to license agreements whereby we may receive royalties and or milestone payments from products subject to regulatory approval.

●

The price of our common stock has been, and may continue to be, volatile.

●

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.

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●

The declaration of dividends is within the discretion of our Board of Directors, 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, fluctuating royalty revenues, our ability to acquire other revenue sources and our ability to manage expenses, including costs relating to our ongoing operations.

●

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

●

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.

●

The terms of our outstanding Series C Preferred Stock and the issuance of additional series of preferred stock may adversely affect rights of our common stockholders.

●

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

●

If we experience an “ownership change,” as defined in Section 382 of the Internal Revenue Code of 1986, as amended, our ability to fully utilize our NOLs on an annual basis will be substantially limited, and the timing of the usage of the NOLs could be substantially delayed, which could therefore significantly impair the value of those benefits.

●

If we experience a “Change of Control,” as defined in Certificate of Designation of the Series C Preferred Stock, the holders of the Series C Preferred Stock shall have the right, at such holder’s option, to require the Company to redeem at the Liquidation Preference then in effect all or a portion of such holder’s shares of Series C Preferred Stock, which would negatively impact our available cash.

A more detailed discussion of these risks and uncertainties and other factors that could affect results is contained in our filings with the SEC, including in Item 1A. “Risk Factors” of our Annual Report on Form 10-K for the year ended December 31, 2023. These risks and uncertainties and other factors should be considered carefully and readers are cautioned not to place undue reliance on such forward-looking statements. As such, no assurance can be given that the future results covered by the forward-looking statements will be achieved. All information in this Quarterly Report on Form 10-Q is as of the date of this report, unless otherwise indicated, and we undertake no duty to update this information.

Item 3. Quantitative and Qualitative Disclosures About Market Risk.

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

Item 4. Controls and Procedures.

Evaluation of Disclosure Controls and Procedures

Our management, consisting of Richard L. Feinstein who serves as our Chief Executive Officer and Chief Financial Officer, has evaluated the effectiveness of our disclosure controls and procedures (as defined in Rules 13a-15(e) and 15d-15(e) under the Securities Exchange Act of 1934, as amended (the “Exchange Act”), as of March 31, 2024. 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 Chief Executive Officer and Chief Financial Officer, to allow timely decisions regarding required disclosures. Based on that evaluation, our Chief Executive Officer and Chief Financial Officer concluded that, as of March 31, 2024, the Company’s disclosure controls and procedures were effective.

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) and 15d-15(f) under the Exchange Act, during the quarter ended March 31, 2024 that have materially affected, or are reasonably likely to materially affect our internal control over financial reporting.

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Part II – OTHER INFORMATION

Item 1. Legal Proceedings

We are not currently a party to any lawsuit or proceeding which, in the opinion of management, is likely to have a material adverse effect on us or our business.

Item 1A. Risk Factors.

There are no material changes from the risk factors previously disclosed in our Annual Report on Form 10-K for the fiscal year ended December 31, 2023 filed with the SEC on March 20, 2024.

Item 2. Unregistered Sales of Equity Securities and Use of Proceeds

None.

Item 3. Defaults Upon Senior Securities

None.

Item 4. Mine Safety Disclosures

Not applicable.

Item 5. Other Information

None.

Item 6. Exhibits

(a) Exhibits required by Item 601 of Regulation S-K.


Exhibit Number	Description	Reference No.
31.1	Certification of Principal Executive Officer and Principal Financial Officer pursuant to Section 302 of the Sarbanes-Oxley Act of 2002*	+
32.1	Certification of Principal Executive Officer and Principal Financial Officer pursuant to Section 906 of the Sarbanes-Oxley Act of 2002*	+
101.INS	Inline XBRL Instance Document	+
101.SCH	Inline XBRL Taxonomy Extension Schema Document	+
101.CAL	Inline XBRL Taxonomy Extension Calculation Linkbase Document	+
101.DEF	Inline XBRL Taxonomy Extension Definition Linkbase Document	+
101.LAB	Inline XBRL Taxonomy Extension Label Linkbase Document	+
101.PRE	Inline XBRL Taxonomy Extension Presentation Linkbase Document	+
104	Cover Page Interactive Data File (formatted as inline XBRL with applicable taxonomy extension information contained in Exhibits 101)	+

+Filed herewith.

*This certification is not deemed filed by the Commission and is not to be incorporated by reference in any filing the Company makes under the Securities Act of 1933 or the Securities Exchange Act of 1934, irrespective of any general incorporation language in any filings.

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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 thereunto duly authorized.

	ENZON PHARMACEUTICALS, INC.
	(Registrant)


Dated:May 10, 2024	/s/ Richard L. Feinstein
	Richard L. Feinstein
	Chief Executive Officer, Chief Financial Officer and Secretary
	(Principal Executive Officer, Principal Financial Officer and Principal Accounting Officer)

Exhibit 31.1

CERTIFICATION PURSUANT TO

SECTION 302 OF

THE SARBANES-OXLEY ACT OF 2002

I, Richard L. Feinstein, certify that:

I have reviewed this Quarterly Report on Form 10-Q for the quarter ended March 31, 2024 of Enzon Pharmaceuticals, Inc.;

Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;

As the registrant’s sole certifying officer, I am responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f)) for the registrant and have:

(a)

designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under my supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to me by others within those entities, particularly during the period in which this report is being prepared;

(b)

designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under my supervision, 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;

(c)

evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report my conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

(d)

disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the registrant’s most recent fiscal quarter (the registrant’s fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting; and

I have disclosed, based on my most recent evaluation of internal control over financial reporting, to the registrant’s auditors and the audit committee of the registrant’s board of directors (or persons performing the equivalent functions):

(a)

All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize and report financial information; and

(b)

Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal control over financial reporting.

May 10, 2024	/s/ Richard L. Feinstein
	Richard L. Feinstein
	Chief Executive Officer, Chief Financial Officer and Secretary
	(Principal Executive Officer and Principal Financial Officer)

Exhibit 32.1

CERTIFICATION PURSUANT TO

18 U.S.C. §1350,

AS ADOPTED PURSUANT TO

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the Quarterly Report of Enzon Pharmaceuticals, Inc. (the Company) on Form 10-Q for the quarterly period ended March 31, 2024 as filed with the Securities and Exchange Commission on the date hereof (the Report), I, Richard L. Feinstein, Chief Executive Officer, Chief Financial Officer and Secretary of the Company, certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that to my knowledge:

The Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company.

May 10, 2024	/s/ Richard L. Feinstein
	Richard L. Feinstein
	Chief Executive Officer, Chief Financial Officer and Secretary
	(Principal Executive Officer and Principal Financial Officer)

A signed original of this written statement required by Section 906 of the Sarbanes-Oxley Act of 2002 has been provided to Enzon Pharmaceuticals, Inc. and will be furnished to the Securities Exchange Commission or its staff upon request.

Document and Entity Information - shares	3 Months Ended
Document and Entity Information - shares	Mar. 31, 2024	May 03, 2024
Document and Entity Information
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2024
Document Transition Report	false
Entity File Number	001-36435
Entity Registrant Name	Enzon Pharmaceuticals, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	22-2372868
Entity Address, Address Line One	20 Commerce Drive (Suite 135)
Entity Address, City or Town	Cranford
Entity Address, State or Province	NJ
Entity Address, Postal Zip Code	07016
City Area Code	732
Local Phone Number	980-4500
Title of 12(b) Security	None
No Trading Symbol Flag	true
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		74,214,603
Entity Central Index Key	0000727510
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q1
Amendment Flag	false

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Current assets:
Cash and cash equivalents	$ 45,988	$ 47,012
Other current assets	481	331
Total current assets	46,469	47,343
Deferred tax asset	360	359
Total assets	46,829	47,702
Current liabilities:
Accounts payable	331	331
Accrued expenses and other current liabilities	190	108
Dividends payable on Series C preferred stock		1,275
Total current liabilities	521	1,714
Commitments and contingencies
Stockholders' equity:
Preferred stock - $0.01 par value, authorized 2,960,000 shares; no shares issued and outstanding at March 31, 2024 and December 31, 2023
Common stock - $0.01 par value, authorized 170,000,000 shares; issued and outstanding 74,214,603 shares at March 31, 2024 and December 31, 2023	742	742
Additional paid-in capital	72,902	73,433
Accumulated deficit	(70,350)	(70,670)
Total stockholders' equity	3,294	3,505
Total liabilities, mezzanine equity and stockholders' equity	46,829	47,702
Mezzanine Equity - Series C Preferred Stock
Mezzanine equity:
Series C preferred stock - $0.01 par value, 40,000 shares authorized, issued and outstanding (liquidation value $1,075 and $1,062 per share) at March 31, 2024 and December 31, 2023	$ 43,014	$ 42,483

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Mar. 31, 2024	Dec. 31, 2023
Mezzanine equity
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized	2,960,000	2,960,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	170,000,000	170,000,000
Common stock, shares issued	74,214,603	74,214,603
Common stock, shares outstanding	74,214,603	74,214,603
Mezzanine Equity - Series C Preferred Stock
Mezzanine equity
Preferred stock, par value	$ 0.01	$ 0.01
Preferred Shares, shares authorized	40,000	40,000
Preferred stock, shares issued	40,000	40,000
Preferred stock, shares outstanding	40,000	40,000
Preferred stock, liquidation value (in dollars per share)	$ 1,075	$ 1,062

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Revenues:
Royalties and milestones, net	$ 0	$ 0
Total revenues	0	0
Operating expenses:
General and administrative	326	285
Total operating expenses	326	285
Operating loss	(326)	(285)
Interest and dividend income	647	447
Income before income tax benefit	321	162
Income tax (expense) benefit	(1)	35
Net income	320	197
Dividends on Series C preferred stock	(531)	(531)
Net loss available to common shareholders	$ (211)	$ (334)
Loss per common share
Basic	$ 0.00	$ 0.00
Diluted	$ 0.00	$ 0.00
Weighted average number of common shares - basic	74,215	74,215
Weighted average number of common shares - diluted	74,215	74,215

CONDENSED CONSOLIDATED STATEMENTS OF MEZZANINE EQUITY AND STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Mezzanine Equity - Series C Preferred Stock Preferred Stock	Mezzanine Equity - Series C Preferred Stock	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Total
Balance at the beginning at Dec. 31, 2022			$ 742	$ 74,708	$ (72,043)	$ 3,407
Balance at the beginning (in shares) at Dec. 31, 2022			74,215,000
Net income					197	197
Preferred stock dividend accumulation				(531)		(531)
Balance at the ending at Mar. 31, 2023			$ 742	74,177	(71,846)	3,073
Balance at the ending (in shares) at Mar. 31, 2023			74,215,000
Balance at the beginning at Dec. 31, 2022	$ 42,483
Balance at the beginning (in shares) at Dec. 31, 2022	40,000
Increase (Decrease) in Temporary Equity [Roll Forward]
Preferred stock dividend accumulation	$ 531
Balance at the ending at Mar. 31, 2023	$ 43,014
Balance at the ending (in shares) at Mar. 31, 2023	40,000
Balance at the beginning at Dec. 31, 2023			$ 742	73,433	(70,670)	3,505
Balance at the beginning (in shares) at Dec. 31, 2023			74,215,000
Net income					320	320
Preferred stock dividend accumulation				(531)		(531)
Balance at the ending at Mar. 31, 2024			$ 742	$ 72,902	$ (70,350)	$ 3,294
Balance at the ending (in shares) at Mar. 31, 2024			74,215,000
Balance at the beginning at Dec. 31, 2023	$ 42,483	$ 42,483
Balance at the beginning (in shares) at Dec. 31, 2023	40,000	40,000
Increase (Decrease) in Temporary Equity [Roll Forward]
Preferred stock dividend accumulation	$ 531
Balance at the ending at Mar. 31, 2024	$ 43,014	$ 43,014
Balance at the ending (in shares) at Mar. 31, 2024	40,000	40,000

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Cash flows from operating activities:
Net income	$ 320,000	$ 197,000
Adjustments to reconcile net income to net cash provided by operating activities:
Deferred income taxes	(1,000)	(36,000)
Changes in operating assets and liabilities	(68,000)	9,000
Net cash provided by operating activities	251,000	170,000
Cash flows from financing activities:
Preferred stock dividend payments	(1,275,000)	(1,275,000)
Net cash used in financing activities	(1,275,000)	(1,275,000)
Net decrease in cash and cash equivalents	(1,024,000)	(1,105,000)
Cash and cash equivalents, beginning of period	47,012,000	46,982,000
Cash and cash equivalents, end of period	45,988,000	45,877,000
Non-cash financing activities:
Accretion of dividend for Series C Preferred Stock	$ 531,000	$ 531,000

Description of Business

3 Months Ended

Mar. 31, 2024

Description of Business

Description of Business

(1)Description of Business

(1)Description of Business (continued)

The Company maintains its principal executive offices at 20 Commerce Drive, Suite 135, Cranford, New Jersey 07016 through a service agreement with Regus Management Group, LLC.

Basis of Presentation

3 Months Ended

Mar. 31, 2024

Basis of Presentation

Basis of Presentation

(2)Basis of Presentation

Interim Financial Statements

Principles of Consolidation

Use of Estimates

(2)Basis of Presentation (continued)

Revenue Recognition

Income Taxes

Recent Accounting Pronouncements

3 Months Ended

Mar. 31, 2024

Recent Accounting Pronouncements

Recent Accounting Pronouncements

(3)Recent Accounting Pronouncements

Financial Instruments and Fair Value

3 Months Ended

Mar. 31, 2024

Financial Instruments and Fair Value

Financial Instruments and Fair Value

(4)Financial Instruments and Fair Value

Supplemental Cash Flow Information

3 Months Ended

Mar. 31, 2024

Supplemental Cash Flow Information

Supplemental Cash Flow Information

(5)Supplemental Cash Flow Information

Cash Dividend

3 Months Ended

Mar. 31, 2024

Cash Dividend

Cash Dividend

(6)Cash Dividend

(6)Cash Dividend (continued)

Loss Per Common Share

3 Months Ended

Mar. 31, 2024

Loss Per Common Share

Loss Per Common Share

(7)Loss Per Common Share

The diluted earnings per common share calculation would normally involve adjusting both the denominator and numerator as described here if the effect is dilutive.


	Three months ended
	March 31,
	2024		2023
Loss Per Common Share – Basic and Diluted:
Net income	$	320	$	197
Dividends on Series C preferred stock		(531)		(531)
Net loss available to common shareholders	$	(211)	$	(334)

Weighted-average common shares outstanding		74,215		74,215

Basic and diluted loss per share	$	(0.00)	$	(0.00)

Income Taxes

3 Months Ended

Mar. 31, 2024

Income Taxes

Income Taxes

(8)Income Taxes

Management of the Company will continue to assess the need for this valuation allowance and will make adjustments when or if appropriate.

The Company has not recorded a liability for unrecognized income tax benefits.

Commitments and Contingent Liabilities

3 Months Ended

Mar. 31, 2024

Commitments and Contingent Liabilities

Commitments and Contingent Liabilities

(9)Commitments and Contingent Liabilities

Accounts Payable, Accrued Expenses

3 Months Ended

Mar. 31, 2024

Accounts Payable, Accrued Expenses

Accounts Payable, Accrued Expenses

(10)Accounts Payable and Accrued Expenses

Accrued expenses and other current liabilities consisted of the following as of March 31, 2024 and 2023 (in thousands):


	March 31,		December 31,
	2024		2023
Professional and consulting fees	$	184	$	92
Other		6		16
	$	190	$	108

Section 382 Rights Plan

3 Months Ended

Mar. 31, 2024

Section 382 Rights Plan

Section 382 Rights Plan

(11)Section 382 Rights Plan

Rights Offering

3 Months Ended

Mar. 31, 2024

Rights Offering

Rights Offering

(12)Rights Offering

(12)Rights Offering (continued)

On an annual basis, the 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 (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 the Company’s common stock. The initial liquidation value of the Series C Preferred Stock was $1,000 per share. At December 31, 2021 the liquidation value of the Series C Preferred Stock was $1,062 per share, inasmuch as no dividend was declared or paid in cash. On December 29, 2022, the Board declared a cash dividend of 3% on the Series C Preferred Stock, aggregating approximately $1,275,000 or $31.86 per share. Accordingly, the liquidation value of the Series C Preferred Stock was $1,062 per share on December 31, 2022. The dividend was paid on January 17, 2023 to the holders of record of the Company’s Series C Preferred Stock as of January 10, 2023. On December 28, 2023, the Board declared a cash dividend of 3% on the Series C Preferred Stock, aggregating approximately $1,275,000 or $31.86 per share. Accordingly, the liquidation value of the Series C Preferred Stock remained at $1,062 per share on December 31, 2023. The dividend was paid on January 17, 2024 to the holders of record of the Company’s Series C Preferred Stock as of January 10, 2024.

Series C Preferred Stock

3 Months Ended

Mar. 31, 2024

Series C Preferred Stock

Series C Preferred Stock

(13)Series C Preferred Stock

In October 2020, the Company issued 40,000 shares of Series C Preferred Stock for an aggregate purchase price of $40.0 million.

There is no prohibition on the repurchase or redemption of Series C Preferred Shares while there is any arrearage in the payment of dividends.

Cash and Cash Equivalents

3 Months Ended

Mar. 31, 2024

Cash and Cash Equivalents

Cash and Cash Equivalents

(14) Cash and Cash Equivalents

Basis of Presentation (Policies)	3 Months Ended
Basis of Presentation (Policies)	Mar. 31, 2024
Basis of Presentation
Interim Financial Statements	Interim Financial Statements The accompanying unaudited condensed consolidated financial statements have been prepared from the books and records of the Company in accordance with United States accounting principles generally accepted in the United States of America (“U.S. GAAP”) for interim financial information and Rule 10-01 of Regulation S-X promulgated by the Securities and Exchange Commission (“SEC”). Accordingly, these financial statements do not include all of the information and footnotes required for complete annual financial statements. Interim results are not necessarily indicative of the results that may be expected for the full year. Interim condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and the notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2023.
Principles of Consolidation	Principles of Consolidation The condensed consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. All intercompany balances and transactions have been eliminated as part of the consolidation.
Use of Estimates	Use of Estimates The preparation of consolidated financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect reported amounts of assets and liabilities, disclosures of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenues and expenses during the reporting period. These estimates include legal and contractual contingencies and income taxes. Although management bases its estimates on historical experience, relevant current information and various other assumptions that are believed to be reasonable under the circumstances, actual results could differ from these estimates.
Revenue Recognition	Revenue Recognition Royalty revenues from the Company’s agreements with third parties and pursuant to the sale of the Company’s former specialty pharmaceutical business are recognized when the Company can reasonably determine the amounts earned. In most cases, this will be upon notification from the third-party licensee, which is typically during the quarter following the quarter in which the sales occurred. The Company does not participate in the selling or marketing of products for which it receives royalties. Because the Company records revenue only when collection is assured, no provision for uncollectible accounts is established upon recognition of revenues. Contingent payments with third parties and pursuant to the sale of the Company’s former specialty pharmaceutical business are recognized as income when the milestone has been achieved and collection is assured, such payments are non-refundable and no further effort is required on the part of the Company or the other party to complete the earning process.
Income Taxes	Income Taxes Income taxes are accounted for under the asset and liability method. 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 realized. The effect of a change in tax rates or laws on deferred tax assets and liabilities is recognized in operations in the period that includes the enactment date of the rate change. A valuation allowance is established to reduce the deferred tax assets to the amounts that are more likely than not to be realized from operations. Tax benefits of uncertain tax positions are recognized only if it is more likely than not that the Company will be able to sustain a position taken on an income tax return. The Company has no liability for uncertain tax positions. Interest and penalties, if any, related to unrecognized tax benefits, would be recognized as income tax expense.

Loss Per Common Share (Tables)

3 Months Ended

Mar. 31, 2024

Loss Per Common Share

Schedule of Loss per common share

Loss per common share information is as follows (in thousands, except per share amounts) for the three months ended March 31, 2024 and 2023:


	Three months ended
	March 31,
	2024		2023
Loss Per Common Share – Basic and Diluted:
Net income	$	320	$	197
Dividends on Series C preferred stock		(531)		(531)
Net loss available to common shareholders	$	(211)	$	(334)

Weighted-average common shares outstanding		74,215		74,215

Basic and diluted loss per share	$	(0.00)	$	(0.00)

Accounts Payable and Accrued Expenses (Tables)

1 Months Ended

Jan. 31, 2024

Accounts Payable, Accrued Expenses

Schedule of Accrued expenses and other current liabilities

Accrued expenses and other current liabilities consisted of the following as of March 31, 2024 and 2023 (in thousands):


	March 31,		December 31,
	2024		2023
Professional and consulting fees	$	184	$	92
Other		6		16
	$	190	$	108

Description of Business (Details)				1 Months Ended	3 Months Ended	12 Months Ended
Description of Business (Details)	Dec. 28, 2023 USD ($) $ / shares	Dec. 29, 2022 USD ($) $ / shares	Oct. 09, 2020 $ / shares	Sep. 30, 2020 USD ($) item $ / shares shares	Mar. 31, 2024 USD ($) $ / shares shares	Dec. 31, 2022 USD ($) $ / shares	Dec. 31, 2023 USD ($) $ / shares shares	Dec. 31, 2021 USD ($) $ / shares	Sep. 23, 2020 $ / shares	Sep. 01, 2020 shares
Description of Business
Amount of operating loss carry forward \| $					$ 102,200,000
License Maintenance Fee \| $						$ 26,000
Common stock, shares outstanding \| shares					74,214,603		74,214,603
Rights Offering
Description of Business
Rights offering and realized in gross proceeds \| $				$ 43,600,000
Amount of operating loss carry forward \| $				$ 100,000,000
Subscription price per Unit									$ 1,090
Number of rights per share of stock \| shares				1						1
Number of subscription rights to be held \| item				1,105
Preferred stock, par value				$ 1
Number of units available for purchase \| shares				40,000
Rights Offering \| Common Stock
Description of Business
Number of shares per unit \| shares				750
Common stock, shares outstanding \| shares					74,214,603
Series C Preferred Stock
Description of Business
Preferred stock, par value					$ 0.01		$ 0.01
Preferred stock, shares outstanding \| shares					40,000		40,000
Percentage of dividend on liquidation preference to be paid in cash					3.00%
Initial dividend per share					$ 1,000
Percentage of annual increase in liquidation preference					5.00%
Cash dividend (as percent)	3.00%	3.00%			5.00%
Aggregated dividend amount \| $	$ 1,275,000	$ 1,275,000			$ 531,000
Preferred stock, liquidation value (in dollars per share)					$ 1,075	$ 1,062	$ 1,062	$ 1,062
Preferred stock, liquidation value \| $						$ 42,483,000
Dividend per share	$ 31.86	$ 31.86			$ 13
Cumulative liquidation value \| $					$ 531,000	$ 42,483,000	$ 42,483,000	$ 2,023,000
Cumulative liquidation value (in dollars per share)					$ 1,075	$ 1,062	$ 1,062	$ 1,062
Series C Preferred Stock \| Rights Offering
Description of Business
Preferred stock, par value				$ 0.01
Percentage of dividend on liquidation preference to be paid in cash			3.00%
Cumulative liquidation value (in dollars per share)			$ 1,000					$ 1,062

Basis of Presentation (Details)	3 Months Ended
Basis of Presentation (Details)	Mar. 31, 2024 USD ($)
Basis of Presentation
Provision for uncollectible accounts	$ 0
Liability for uncertain tax positions	$ 0

Financial Instruments and Fair Value (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Financial Instruments and Fair Value
Cash and cash equivalents, at carrying value	$ 45.9	$ 47.0

Supplemental Cash Flow Information (Details) - USD ($)	3 Months Ended
Supplemental Cash Flow Information (Details) - USD ($)	Mar. 31, 2024	Mar. 31, 2023
Supplemental Cash Flow Information
Cash paid for income taxes	$ 0	$ 0
Interest paid, net	$ 0	$ 0

Cash Dividend (Details) - Series C Preferred Stock - USD ($)			3 Months Ended
	Dec. 28, 2023	Dec. 29, 2022	Mar. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Cash Dividend
Cash dividend (as percent)	3.00%	3.00%	5.00%
Aggregated dividend amount	$ 1,275,000	$ 1,275,000	$ 531,000
Dividend per share	$ 31.86	$ 31.86	$ 13
Cumulative liquidation value			$ 531,000	$ 42,483,000	$ 42,483,000	$ 2,023,000
Cumulative liquidation value (in dollars per share)			$ 1,075	$ 1,062	$ 1,062	$ 1,062

Loss Per Common Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Loss Per Common Share - Basic and Diluted:
Net income	$ 320	$ 197
Dividends on Series C preferred stock	(531)	(531)
Net loss available to common shareholders	$ (211)	$ (334)
Weighted-average common shares outstanding - Basic	74,215	74,215
Weighted-average common shares outstanding- Diluted	74,215	74,215
Loss per common share - Basic	$ 0.00	$ 0.00
Loss per common share - Diluted	$ 0.00	$ 0.00

Income Taxes - Additional Information (Details) - USD ($)	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Income Taxes
Income tax (expense) benefit	$ 1,000	$ (35,000)
Deferred income taxes	(1,000)	(36,000)
Operating loss carryforwards	$ 102,200,000
Tax credit carryforward, limitations on use	. Under the Tax Cuts and Jobs Act, net operating losses generated in tax years beginning after December 31, 2017 have an unlimited carryforward period, and the amount of net operating loss allowed to be utilized each year is limited to 80% of taxable income
New Jersey state income tax
Income Taxes
Income tax (expense) benefit	$ 500	$ (34,500)
Operating loss carryforwards	24,500,000
Domestic Tax Authority
Income Taxes
Operating loss carryforwards	99,100,000
Domestic Tax Authority \| R & D credit carryforwards
Income Taxes
Tax Credit Carryforward Amount	$ 9,400,000

Commitments and Contingent Liabilities (Details)	Jan. 17, 2024 $ / shares
Commitments and Contingent Liabilities
Stock Bid Price	$ 0.10
Closing Stock Bid Price	$ 0.10

Accounts Payable and Accrued Expenses (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Accounts Payable, Accrued Expenses
Professional and consulting fees	$ 184	$ 92
Other	6	16
Accrued expenses and other current liabilities, Total	$ 190	$ 108

Accounts Payable and Accrued Expenses (Details) - USD ($)	Mar. 31, 2024	Dec. 31, 2022
Merck
Accounts Payable and Accrued Expenses
Accrued royalties	$ 331,000	$ 331,000

Section 382 Rights Plan (Details)	Aug. 14, 2020 USD ($) $ / shares shares	Mar. 31, 2024 $ / shares	Dec. 31, 2023 $ / shares
Section 382 Rights Plan
Preferred stock, par value (in dollars per share) \| $ / shares		$ 0.01	$ 0.01
Section 382 Rights Plan
Section 382 Rights Plan
Rights per share distributed as dividend \| shares	1
Number of preferred stock purchase right for each common stockholder \| shares	1
Section 382 Rights Plan \| Series A-1 Junior Participating Preferred Stock
Section 382 Rights Plan
Number of common stock eligible for each warrant become exercisable \| shares	1
Preferred stock, par value (in dollars per share) \| $ / shares	$ 0.01
Purchase price per right (in dollars per share) \| $ / shares	$ 1.20
Number of votes for fractional share \| $	1

Rights Offering (Details) - USD ($)					3 Months Ended
Rights Offering (Details) - USD ($)	Dec. 28, 2023	Dec. 29, 2022	Oct. 09, 2020	Sep. 01, 2020	Mar. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Sep. 30, 2020
Rights Offering
Preferred stock, par value (in dollars per share)					$ 0.01	$ 0.01
Common stock, shares outstanding					74,214,603	74,214,603
Series C Preferred Stock
Rights Offering
Percentage of dividend on liquidation preference to be paid in cash					3.00%
Cumulative liquidation value (in dollars per share)					$ 1,075	$ 1,062	$ 1,062	$ 1,062
Cash dividend (as percent)	3.00%	3.00%			5.00%
Aggregated dividend amount	$ 1,275,000	$ 1,275,000			$ 531,000
Dividend per share	$ 31.86	$ 31.86			$ 13
Rights Offering
Rights Offering
Number of subscription rights to be held for purchase of a unit				1,105
Number of units entitled for 1,105 subscription rights held				1
Subscription price per unit of a right				$ 1,090
Number of common stock eligible for each warrant become exercisable				1					1
Rights Offering \| Series C Preferred Stock
Rights Offering
Preferred stock, par value (in dollars per share)				$ 0.01
Number of common shares for unit				750
Percentage of dividend on liquidation preference to be paid in cash			3.00%
Cumulative liquidation value (in dollars per share)			$ 1,000					$ 1,062
Annual increase in percentage of the liquidation preference per share, if dividend not paid in cash			5.00%
Rights Offering \| Investment Agreement \| Icahn Capital LP
Rights Offering
Number of units sold			40,000
Issued and gross proceeds			$ 43,600,000
Common stock, shares outstanding			74,214,603
Rights Offering \| Investment Agreement \| Icahn Capital LP \| Series C Preferred Stock
Rights Offering
Common stock, shares outstanding			40,000

Series C Preferred Stock (Details) - USD ($)		1 Months Ended	3 Months Ended	12 Months Ended
Series C Preferred Stock (Details) - USD ($)	Dec. 31, 2021	Oct. 31, 2020	Mar. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Series C Preferred Stock
Proceeds from issuance of series c preferred stock		$ 40,000,000.0
Series C Preferred Stock
Series C Preferred Stock
Rights offering, proceeds (in shares)		40,000
Increase in liquidation preference value (in percentage)	5.00%		5.00%
Increase in liquidation preference value	$ 50
Cumulative liquidation value	2,023,000		$ 531,000	$ 42,483,000	$ 42,483,000
Preferred stock cumulative liquidation value	$ 42,483,000		$ 43,014,000
Cumulative liquidation value (in dollars per share)	$ 1,062		$ 1,075	$ 1,062	$ 1,062
Preferred stock, liquidation preference (in percentage)				3.00%	3.00%
Preferred stock, increase in liquidation preference (in dollars per share)			$ 13

Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended
Pay vs Performance Disclosure - USD ($) $ in Thousands	Mar. 31, 2024	Mar. 31, 2023
Pay vs Performance Disclosure
Net Income (Loss)	$ 320	$ 197

Insider Trading Arrangements	3 Months Ended
Insider Trading Arrangements	Mar. 31, 2024
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false