0001437749-24-012210 | 10-K | XBRL Viewer | Windtree Therapeutics INC DE

Property, Plant and Equipment Disclosure [Text Block]

Note 6 – Property and Equipment

Property and equipment is comprised of the following:

	December 31,
(in thousands)	2023			2022

Leasehold improvements	$	2,664		$	2,649
Manufacturing, laboratory & office equipment		870			881
Furniture & fixtures		390			390
Subtotal		3,924			3,920
Accumulated depreciation and amortization		(3,741	)		(3,658	)
Property and equipment, net	$	183		$	262

Depreciation expense on property and equipment for the years ended December 31, 2023 and 2022 was $0.1 million and $0.5 million, respectively. During the first quarter of 2022, we determined that certain manufacturing and laboratory equipment assets related to the KL4 surfactant platform would be abandoned by March 31, 2022. We accelerated depreciation of these assets during the first quarter of 2022, resulting in $0.4 million of additional depreciation expense for the three months ended March 31, 2022. During the second quarter of 2022, the abandoned assets and certain other KL4 surfactant platform assets were disposed.

Note 13 - Collaboration, Licensing and Research Funding Agreements (Details Textual) $ in Millions		1 Months Ended	3 Months Ended	12 Months Ended
	Mar. 19, 2021 EUR (€)	Oct. 31, 2014 USD ($)	Jun. 30, 2019 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2019 EUR (€)	Dec. 31, 2022 USD ($)	Aug. 17, 2022 USD ($)	Sep. 30, 2020 USD ($)	Mar. 18, 2020
Term Sheet With Lee [Member]
Proceeds for Payments to Develop Product				$ 1.0
Financing of Product, Percent of Financing That Must be Repaid to Discontinue Revenue Sharing										125.00%
Financing of Product, Percent of Revenue Shared With Financer										50.00%
Term Sheet With Lee [Member] \| Other Liabilities [Member]
Contractual Obligation, Total							$ 3.8
A&R License Agreement With Lee [Member]
Proceeds for Payments to Develop Product			$ 1.0
Maximum Amount May be Received for Potential Milestone Payments								$ 78.9
Johnson and Johnson - License Agreement [Member]
Potential License Fee Payable					$ 2.5
Payment of License Cost Subject to Regulatory Approval					$ 1.0
Percent of Cash Upfront and Milestone Fees Payable to Esteve					10.00%
Maximum Aggregate Cash Upfront and Milestone Fees Payable to Esteve					$ 20.0
Universita Degli Studi Do Miano-Biocca [Member]
Payment of License Cost for New Compounds Modulating \| €						€ 100,000
Payment of License Cost Upon Obtaining Marketing Authorization \| €						€ 1,500,000
Agreement for Scientific Collaboration, or the New SERCA2a Agreement, with Bicocca [Member]
Payment of License Cost for Research Activities and to Cover Laboratory Space and Operation Costs \| €	€ 200,000
Payment of License Cost for Execution of an Assignment \| €	25,000
Payment of License Cost for New Compounds Developed \| €	75,000
Payment of License Cost upon Obtaining Marketing Authorization in the U.S., EU, or China of New Compounds \| €	€ 1,500,000
Battelle Applies [Member]
Maximum Royalty Paid on Completion of Activities Under the Agreement		$ 25.0		$ 35.0
Lee’s Pharmaceutical Holdings Limited [Member] \| AEROSURF Funding Term Sheet [Member]
Nonrefundable Payments, Maximum Financing to Be Received Under Special Circumstances									$ 2.8

Note 11 - Mezzanine Equity and Stockholders' Equity

12 Months Ended

Dec. 31, 2023

Equity [Text Block]

Note 11 – Mezzanine Equity and Stockholders’ Equity

April 2023 Public Offering

On April 20, 2023, we commenced the April 2023 Offering for a public offering of an aggregate of 3,686,006 units with each unit consisting of one share of common stock and a warrant, or the April 2023 Warrants. The April 2023 Warrants were immediately exercisable for shares of common stock at a price of $2.93 per share and expire five years from the date of issuance. The shares of common stock and the April 2023 Warrants were immediately separable and were issued separately in the April 2023 Offering.

In addition, Ladenburg exercised in full the Overallotment Option to purchase up to 552,900 additional shares of common stock and/or warrants to purchase up to 552,900 additional shares of common stock.

The closing of the April 2023 Offering occurred on April 24, 2023, inclusive of the Overallotment Option. The offering price to the public was $2.93 per unit resulting in gross proceeds to us of approximately $12.4 million. After deducting underwriting discounts and commissions and other estimated offering expenses payable by us, and excluding the proceeds, if any, from the exercise of the April 2023 Warrants issued pursuant to this April 2023 Offering, the net proceeds to us were approximately $10.8 million.

We have determined that the appropriate accounting treatment under ASC 480, Distinguishing Liabilities from Equity, or ASC 480, is to classify the shares of common stock and the April 2023 Warrants issued in the April 2023 Offering as equity. We have also determined that the April 2023 Warrants were not in their entirety a derivative under the scope of ASC 815, Derivatives and Hedging, or ASC 815, due to the scope exception under ASC 815-10-15-74, nor are there any material embedded derivatives that require separate accounting. We allocated the net proceeds from the April 2023 Offering based on the relative fair value of the common stock and the April 2023 Warrants.

January 2023 Warrant Exercise Inducement Offer Letters

On January 20, 2023, we entered into warrant exercise inducement offer letters with certain holders of certain of our: (i) warrants issued in December 2019 to purchase 1,573 shares of common stock with an exercise price of $604.50 per share; (ii) warrants issued in May 2020 to purchase 5,598 shares of common stock with an exercise price of $398.75 per share, and (iii) warrants issued in March 2021 to purchase 89,001 shares of common stock with an exercise price of $180.00 per share (collectively, the January 2023 Existing Warrants).

Pursuant to the terms of the inducement letters, we agreed to amend the January 2023 Existing Warrants by lowering the exercise price of the January 2023 Existing Warrants to $10.00 per share. Additionally, the exercising holders agreed to exercise for cash all of their January 2023 Existing Warrants to purchase an aggregate of 96,172 shares of common stock in exchange for our agreement to issue to such exercising holders new warrants, or the January 2023 New Warrants, to purchase up to an aggregate of 192,344 shares of common stock. We received aggregate gross and net proceeds of approximately $1.0 million and $0.7 million, respectively, from the exercise of the January 2023 Existing Warrants by the exercising holders.

Each January 2023 New Warrant is exercisable into shares of common stock at a price per share of $10.76, will initially be exercisable six months following its date of issuance, or the January 2023 Initial Exercise Date, and will expire on the fifth anniversary of the January 2023 Initial Exercise Date.

February 2023 Warrant Exercise Inducement Offer Letter

On February 21, 2023, we entered into a warrant exercise inducement offer letter with Panacea Venture Healthcare Fund I, L.P., a holder of certain of our: (i) warrants issued in July 2018 to purchase 1,250 shares of common stock with an exercise price of $600.00 per share; (ii) warrants issued in December 2018 to purchase 9,960 shares of common stock with an exercise price of $607.50 per share; (iii) warrants issued in December 2019 to purchase 5,519 shares of common stock with an exercise price of $604.50 per share; and (iv) warrants issued in May 2020 to purchase 5,517 shares of common stock with an exercise price of $398.75 per share (collectively, the February 2023 Existing Warrants).

Pursuant to the terms of the inducement letter, we agreed to amend the February 2023 Existing Warrants by lowering the exercise price of the February 2023 Existing Warrants to $7.06 per share. Additionally, Panacea agreed to exercise for cash all of their February 2023 Existing Warrants to purchase an aggregate of 22,246 shares of common stock in exchange for our agreement to issue to Panacea new warrants, or the February 2023 New Warrants, to purchase up to an aggregate of 44,492 shares of common stock. We received aggregate gross and net proceeds of approximately $0.2 million and $0.1 million, respectively, from the exercise of the February 2023 Existing Warrants by Panacea.

Each February 2023 New Warrant is exercisable into shares of common stock at a price per share of $10.76, will initially be exercisable six months following its date of issuance, or the February 2023 Initial Exercise Date, and will expire on the fifth anniversary of the February 2023 Initial Exercise Date.

Accounting for the January 2023 and February 2023 Warrant Exercise Inducement Offer Letters

The amendment of the January 2023 Existing Warrants and the February 2023 Existing Warrants by lowering the exercise prices and issuing the January 2023 New Warrants and the February 2023 New Warrants is considered a modification of the January 2023 Existing Warrants and the February 2023 Existing Warrants under the guidance of ASU 2021-04. The modification is consistent with the “Equity Issuance” classification under that guidance as the reason for the modification was to induce the holders to cash exercise their warrants, resulting in the imminent exercise of the January 2023 Existing Warrants and the February 2023 Existing Warrants, which raised equity capital and generated net proceeds for us of approximately $0.7 million and $0.1 million, respectively. The total fair value of the consideration of the modification includes the incremental fair value of the January 2023 Existing Warrants and the February 2023 Existing Warrants (determined by comparing the fair values immediately prior to and immediately after the modification) and the initial fair value of the January 2023 New Warrants and the February 2023 New Warrants. The fair values were calculated using the Black-Scholes model and we determined that the total fair value of the consideration related to the modification of the January 2023 Existing Warrants and the February 2023 Existing Warrants, including the initial fair value of the January 2023 New Warrants and the February 2023 New Warrants, was $1.2 million and $0.3 million, respectively.

Series A Preferred Stock

We are authorized to issue 5,000,000 shares of preferred stock, with a par value of $0.001 per share.

On November 17, 2022, our Board of Directors declared a dividend of one one-thousandth (1/1,000th) of a share of Series A Preferred Stock, par value $0.001 per share, or Series A Preferred Stock, for each outstanding share of our common stock to stockholders of record at 5:00 p.m. Eastern Time on November 28, 2022. The Certificate of Designation of Series A Preferred Stock was filed with the Delaware Secretary of State and became effective on November 18, 2022 and authorized the issuance of 40,000 shares of Series A Preferred Stock. The dividend was based on the number of outstanding shares of common stock as of November 28, 2022 and resulted in 38,610.119 shares of Series A Preferred Stock that were declared as a stock dividend on December 2, 2022. Each share of Series A Preferred Stock entitles the holder thereof to 1,000,000 votes per share. The shares of Series A Preferred Stock vote together with the outstanding shares of common stock as a single class exclusively with respect to (1) any proposal to adopt an amendment to our Amended and Restated Certificate of Incorporation, as amended, to reclassify the outstanding shares of common stock into a smaller number of shares of common stock at a ratio specified in or determined in accordance with the terms of such amendment, or the Reverse Stock Split, and (2) any proposal to adjourn any meeting of stockholders called for the purpose of voting on the Reverse Stock Split. The Series A Preferred Stock was not entitled to vote on any other matter, except to the extent required under the General Corporation Law of the State of Delaware.

All shares of Series A Preferred Stock that are not present in person or by proxy at any meeting of stockholders held to vote on the Reverse Stock Split and the adjournment proposal as of immediately prior to the opening of the polls at such meeting, or the Initial Redemption Time, will automatically be redeemed in whole, but not in part, by us at the Initial Redemption Time. All shares that were not redeemed pursuant to the Initial Redemption Time will be redeemed if ordered by the Board of Directors or automatically upon the approval by our stockholders of the Reverse Stock Split at any meeting of the stockholders held for the purpose of voting on such proposal. Each share of Series A Preferred Stock is entitled to receive $0.01 in cash for each 10 whole shares of Series A Preferred Stock immediately prior to the redemption.

Upon issuance of the Series A Preferred Stock, we were not solely in control of the redemption of the shares of Series A Preferred Stock since the holders had the option of deciding whether to attend or return a proxy card for the Special Meeting, which determined whether a given holder’s shares of Series A Preferred Stock were redeemed at the Initial Redemption Time. Since the redemption of the Series A Preferred Stock was not solely in the control of us, the shares of Series A Preferred Stock are classified within mezzanine equity. The shares of Series A Preferred Stock were recorded at redemption value, which approximates fair value.

On February 7, 2023, we held a Special Meeting of Stockholders, or the Special Meeting, where our stockholders voted on and approved an amendment to our Amended and Restated Certificate of Incorporation, as amended, to effect the Reverse Stock Split and adjourn the Special Meeting, at which point all shares of Series A Preferred Stock were redeemed, and were no longer issued and outstanding as of such date.

At-The-Market Program

On November 9, 2023, we entered into an At-The-Market Offering Agreement with Ladenburg, pursuant to which we may offer and sell, from time to time at our sole discretion, shares of our common stock through Ladenburg as agent and/or principal (subject to the limitations of General Instruction I.B.6 of Form S-3) through an at-the-market program, or the 2023 ATM Program. We are not obligated to make any sales under the 2023 ATM Program. When we issue sale notices to Ladenburg, we designate the maximum amount of shares to be sold by Ladenburg daily and the minimum price per share at which shares may be sold. Ladenburg may sell shares by any method permitted by law deemed to be an “at-the-market offering” as defined in Rule 415(a)(4) under the Securities Act of 1933, as amended, or in privately negotiated transactions.

Sales under the 2023 ATM Program will be made pursuant to our “shelf” registration statement on Form S-3 (No. 333-261878) filed with the SEC on December 23, 2021, and declared effective on January 3, 2022 and a prospectus supplement related thereto. We are currently subject to the limitations contained in General Instruction I.B.6 of Form S-3. As a result, we are limited to selling no more than one-third of the aggregate market value of the equity held by non-affiliates, or the public float, during any 12-month period, and, as of April 16, 2024, we had sold substantially all that we are permitted to sell under the Form S-3 pursuant to General Instruction I.B.6. If our public float increases, we will have additional availability under such limitations, and if our public float increases to $75 million or more, we will no longer be subject to such limitations. There can be no assurance that our public float will increase or that we will no longer be subject to such limitations.

Either party may suspend the offering under the 2023 ATM Program by notice to the other party. The 2023 ATM Program will terminate upon the earlier of (i) the sale of all shares subject to the 2023 ATM Program or (ii) termination of the 2023 ATM Program in accordance with its terms. Either party may terminate the 2023 ATM Program at any time upon five business days' prior written notification to the other party in accordance with the related agreement.

We agreed to pay Ladenburg a commission of 3% of the gross sales price of any shares sold pursuant to the 2023 ATM Program. The rate of compensation will not apply when Ladenburg acts as principal, in which case such rate shall be separately negotiated. We also agreed to reimburse Ladenburg for the fees and disbursements of its counsel in an amount not to exceed $60,000, in addition to certain ongoing disbursements of its legal counsel up to $3,000 per calendar quarter.

During the fourth quarter of 2023, we sold 848,367 shares of our common stock under the 2023 ATM Program resulting in aggregate gross and net proceeds to us of approximately $0.8 million. During the first quarter of 2024, we sold 2,576,153 shares of our common stock under the 2023 ATM Program resulting in aggregate gross and net proceeds to us of approximately $1.4 million.

On September 17, 2020, we entered into an At-The-Market Offering Agreement with Ladenburg, or the 2020 ATM Program, pursuant to which we were able to offer and sell, from time to time at our sole discretion, up to a maximum of $10.0 million of shares of our common stock through Ladenburg as agent and/or principal under the 2020 ATM Program. For the year ended December 31, 2022, we sold 206,824 shares of our common stock under the 2020 ATM Program resulting in aggregate gross proceeds to us of approximately $4.4 million and net proceeds of approximately $4.3 million.

The shares of common stock issued and sold under the 2020 ATM Program were registered under our Registration Statement on Form S-3 (File No. 333-248874), which was declared effective by the SEC on September 29, 2020 and expired on September 29, 2023. The 2020 ATM Program was terminated by us and Ladenburg on November 9, 2023.

Common Shares Reserved for Future Issuance

Common shares reserved for potential future issuance upon exercise of warrants

The chart below summarizes shares of our common stock reserved for future issuance upon the exercise of warrants:

	December 31,
(in thousands, except price per share data)		2023	2022		Exercise Price	Expiration Date
Investors - April 2023 financing		4,239	-	$	2.93	04/24/28
Investors - February 2023 warrant repricing		44	-	$	10.76	07/21/28
Investors - January 2023 warrant repricing		192	-	$	10.76	06/20/28
Investors - March 2021 financing		96	185	$	180.00	03/25/26
Service Agreement - 2021 warrants		3	3	$	412.50	02/09/24
Investors - May 2020 financing		52	63	$	399.00	05/22/25
Investors - December 2019 financing		22	29	$	604.50	12/06/24
Investors - AEROSURF		20	20	$	-	02/14/24
Investors - December 2018 financing - long-term		-	26	$	607.50	12/04/23
Battelle - 2018 payables restructuring agreement ⁽¹⁾		-	1	$	975.00	12/07/23
Panacea Venture Management Company Ltd.		-	1	$	600.00	07/02/23
LPH II Investments Limited		1	1	$	828.00	04/04/25
Investors - February 2017 financing		2	2	$	4,110.00	02/15/24
Battelle - 2014 collaboration agreement		1	1	$	210,000.00	10/10/24
Total		4,672	332

⁽¹⁾	See the section titled, “Note 13 – Collaboration, Licensing and Research Funding Agreements,” for further details on the Battelle collaboration agreement.

Common shares reserved for potential future issuance upon granting of additional equity incentive awards

The 2020 Equity Incentive Plan, or the 2020 Plan, initially provided for up to a maximum of approximately 31,000 shares of common stock to be available for issuance pursuant to stock-based awards granted under the 2020 Plan. On August 15, 2023, at the Annual Meeting of Stockholders, our stockholders approved an amendment and restatement of the 2020 Plan to increase the authorized shares under the existing 2020 Plan by 645,000 shares and to remove the 2020 Plan’s evergreen provision. See the section titled, “Note 12 – Stock Options and Stock-based Employee Compensation.”

As of December 31, 2023, we had approximately 0.3 million shares available for potential future issuance under the 2020 Plan.

The entire disclosure for equity.

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+ Details

Note 16 - Income Taxes - Deferred Tax Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Net operating loss carryforwards (federal and state)	$ 158,926	$ 185,591
Research and development tax credit	17,081	17,671
Compensation expense on stock	3,940	4,166
Other accrued	1,386	1,293
Capitalized R&D expenses	3,606	2,369
Depreciation	355	191
Total long-term deferred tax assets	185,294	211,281
IPR&D	(5,058)	(5,061)
Total long-term deferred tax liabilities	(5,058)	(5,061)
Valuation allowance	(185,294)	(211,281)
Deferred tax liabilities, net	$ (5,058)	$ (5,061)

Note 12 - Stock Options and Stock-based Employee Compensation - Restricted Stock Units (Details) - Restricted Stock Units (RSUs) [Member] shares in Thousands	12 Months Ended
	Dec. 31, 2023 $ / shares shares
Balance (in shares) \| shares	11
Weighted- Average Grant Date Fair Value, Outstanding, Beginning Balance (in dollars per share) \| $ / shares	$ 49.5
Awarded (in shares) \| shares	142
Awarded, Weighted- Average Grant Date Fair Value, Outstanding (in dollars per share) \| $ / shares	$ 1.21
Vested (in shares) \| shares	(3)
Vested Weighted- Average Grant Date Fair Value, Outstanding (in dollars per share) \| $ / shares	$ 48.55
Cancelled (in shares) \| shares	(3)
Cancelled, Weighted- Average Grant Date Fair Value, Outstanding (in dollars per share) \| $ / shares	$ 49.57
Balance (in shares) \| shares	147
Weighted- Average Grant Date Fair Value, Outstanding (in dollars per share) \| $ / shares	$ 2.94

Note 14 - Related Party Transactions (Details Textual) - USD ($) $ / shares in Units, $ in Thousands		12 Months Ended
	Feb. 21, 2023	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Aug. 17, 2022
Other Liabilities, Noncurrent		$ 3,800	$ 3,800
Research and Development Expense		8,341	11,099
Accrued Liabilities, Current		1,618	1,552
Stock Issued During Period, Value, Exercise Of Warrants		843
Proceeds from Warrant Exercises		843	0
February 2023 Existing Warrants [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)	$ 7.06
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)	22,246
Stock Issued During Period, Value, Exercise Of Warrants	$ 200
Proceeds from Warrant Exercises	$ 100
Panacea Venture Healthcare Fund I, L.P. [Member] \| February 2023 Existing Warrants [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)	$ 7.06
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)	22,246
Stock Issued During Period, Shares, Exercise of Warrants (in shares)	44,492
Stock Issued During Period, Value, Exercise Of Warrants	$ 200
Proceeds from Warrant Exercises	$ 100
AEROSURF Funding Term Sheet [Member] \| Lee’s Pharmaceutical Holdings Limited [Member]
Nonrefundable Payments				$ 1,000
Other Liabilities, Noncurrent		3,800	3,800
Contractual Obligation, Total		$ 0
Research and Development Expenses for Services Provided [Member] \| Lee’s Pharmaceutical Holdings Limited [Member]
Research and Development Expense			400
Accrued Liabilities, Current			$ 300
A&R License Agreement With Lee [Member]
Maximum Amount May be Received for Potential Milestone Payments					$ 78,900
Lee’s Pharmaceutical Holdings Limited [Member] \| Windtree Therapeutics [Member]
Ownership Percentage		2.00%	13.00%
Panacea [Member] \| Windtree Therapeutics [Member]
Ownership Percentage		1.00%	9.00%

Note 17 - Leases - Lease Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Operating lease cost	$ 536	$ 692
Variable lease cost	13	9
Sublease income	(44)	0
Total lease cost	505	701
Operating cash flows used for operating leases	$ 559	$ 730
Weighted average remaining lease term (in years) (Year)	3 years 2 months 12 days	4 years 1 month 6 days
Weighted average incremental borrowing rate	7.07%	7.08%

Note 4 - Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2023

Schedule of Intangible Assets and Goodwill [Table Text Block]

	December 31,
(in thousands)	2023		2022

Istaroxime drug candidate	$	22,340	$	22,340
Rostafuroxin drug candidate		2,910		2,910
Intangible assets		25,250		25,250

Goodwill	$	-	$	3,058

Note 16 - Income Taxes (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Deferred Income Tax Expense (Benefit), Total	$ 0	$ (1,367)
Operating Loss Carryforwards	620,400	637,400
Operating Loss Carryforwards Not Subject to Expiration	101,100
Non-US [Member]
Capitalized Research and Development Expense	5,400	2,000
State and Local Jurisdiction [Member]
Operating Loss Carryforwards	576,300	593,300
State and Local Jurisdiction [Member] \| PA Department of Revenue [Member]
Operating Loss Carryforwards	575,300
Research Tax Credit Carryforward [Member]
Tax Credit Carryforward, Amount	16,500	17,000
Orphan Drug Tax Credit [Member]
Tax Credit Carryforward, Amount	$ 600	$ 600

Note 16 - Income Taxes (Tables)

12 Months Ended

Dec. 31, 2023

Schedule of Components of Income Tax Expense (Benefit) [Table Text Block]

	December 31,
(in thousands)	2023		2022
Deferred expense (benefit):
Foreign	$	-	$	(1,367	)
Total deferred expense (benefit)		-		(1,367	)
Total income tax expense (benefit)	$	-	$	(1,367	)

Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]

	December 31,
(in thousands)	2023			2022

Income tax benefit, statutory rates	$	(4,261	)	$	(8,521	)
State taxes on income, net of federal benefit		(625	)		903
Net operating loss expirations		5,875			3,485
Intangibles		613			2,561
Research and development tax credit		490			825
Foreign rate differential		37			196
Stock compensation		464			-
Employee related and other		(575	)		467
Change in state tax rates		23,993			-
Other		-			(17	)
Income tax expense / (benefit), statutory rates		26,011			(101	)
Valuation allowance		(26,011	)		(1,266	)
Income tax benefit, net	$	-		$	(1,367	)

Schedule of Deferred Tax Assets and Liabilities [Table Text Block]

	December 31,
(in thousands)	2023			2022

Long-term deferred assets:
Net operating loss carryforwards (federal and state)	$	158,926		$	185,591
Research and development tax credit		17,081			17,671
Compensation expense on stock		3,940			4,166
Other accrued		1,386			1,293
Capitalized R&D expenses		3,606			2,369
Depreciation		355			191
Total long-term deferred tax assets		185,294			211,281
Long-term deferred liabilities:
IPR&D		(5,058	)		(5,061	)
Total long-term deferred tax liabilities		(5,058	)		(5,061	)
Valuation allowance		(185,294	)		(211,281	)
Deferred tax liabilities, net	$	(5,058	)	$	(5,061	)

Note 11 - Mezzanine Equity and Stockholders' Equity (Tables)

12 Months Ended

Dec. 31, 2023

Common Shares Reserved for Future Issuance, Warrants [Table Text Block]

	December 31,
(in thousands, except price per share data)		2023	2022		Exercise Price	Expiration Date
Investors - April 2023 financing		4,239	-	$	2.93	04/24/28
Investors - February 2023 warrant repricing		44	-	$	10.76	07/21/28
Investors - January 2023 warrant repricing		192	-	$	10.76	06/20/28
Investors - March 2021 financing		96	185	$	180.00	03/25/26
Service Agreement - 2021 warrants		3	3	$	412.50	02/09/24
Investors - May 2020 financing		52	63	$	399.00	05/22/25
Investors - December 2019 financing		22	29	$	604.50	12/06/24
Investors - AEROSURF		20	20	$	-	02/14/24
Investors - December 2018 financing - long-term		-	26	$	607.50	12/04/23
Battelle - 2018 payables restructuring agreement ⁽¹⁾		-	1	$	975.00	12/07/23
Panacea Venture Management Company Ltd.		-	1	$	600.00	07/02/23
LPH II Investments Limited		1	1	$	828.00	04/04/25
Investors - February 2017 financing		2	2	$	4,110.00	02/15/24
Battelle - 2014 collaboration agreement		1	1	$	210,000.00	10/10/24
Total		4,672	332

Note 5 - Fair Value Measurements (Details Textual) $ in Thousands	Dec. 31, 2023 USD ($)	Jun. 30, 2023 USD ($)	Dec. 31, 2022 USD ($)
Goodwill	$ 0	$ 0	$ 3,058
Measurement Input, Discount Rate [Member]
Indefinite Lived Intangible Assets, Measurement Input			0.20
Measurement Input, Tax Rate [Member]
Indefinite Lived Intangible Assets, Measurement Input			0.30

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

Note 10 - Restructured Debt Liability

12 Months Ended

Dec. 31, 2023

Long-Term Debt [Text Block]

Note 10 – Restructured Debt Liability

On October 27, 2017, we and Deerfield entered into the Exchange and Termination Agreement, or the Milestone Agreement, pursuant to which (i) promissory notes evidencing a loan with affiliates of Deerfield in the aggregate principal amount of $25.0 million and (ii) warrants to purchase up to 167 shares of our common stock at an exercise price of $118,020.00 per share held by Deerfield were cancelled in consideration for (x) a cash payment in the aggregate amount of $2.5 million, (y) 474 shares of common stock, representing 2% of fully-diluted shares outstanding (as defined in the Milestone Agreement) on the closing date, and (z) the right to receive certain milestone payments based on achievement of specified AEROSURF development and commercial milestones, which, if achieved, could potentially total up to $15.0 million. In addition, a related security agreement, pursuant to which Deerfield held a security interest in substantially all of our assets, was terminated. We established a $15.0 million long-term liability for the contingent milestone payments potentially due to Deerfield under the Milestone Agreement. The liability has been recorded at the full value of the contingent milestones and will continue to be carried at full value until the milestones are achieved and paid or the milestones are not achieved and the liability is written off as a gain on debt restructuring.

As of December 31, 2023 and 2022, the restructured debt liability balance was $15.0 million.

On January 24, 2024, we and affiliates of Deerfield entered into an Exchange and Termination Agreement wherein Deerfield agreed to terminate its rights to receive the milestone payments (See the section titled, “Note 18 – Subsequent Events”).

Note 17 - Leases - Future Minimum Lease Payments (Details) $ in Thousands	Dec. 31, 2023 USD ($)
2024	$ 531
2025	570
2026	581
2027	97
Total lease payments	1,779
Less imputed interest	(182)
Total operating lease liabilities	$ 1,597

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Research and development	$ 8,341	$ 11,099
General and administrative	9,198	10,790
Loss on impairment of goodwill	3,058	12,624
Loss on impairment of intangible assets	0	6,820
Total operating expenses	20,597	41,333
Operating loss	(20,597)	(41,333)
Other income (expense):
Interest income	325	109
Interest expense	(50)	(53)
Other income, net	31	702
Total other income, net	306	758
Loss before income taxes	(20,291)	(40,575)
Deferred income tax benefit	0	1,367
Net loss	$ (20,291)	$ (39,208)
Net loss per common share
Basic and diluted (in dollars per share)	$ (5.24)	$ (62.23)
Weighted average number of common shares outstanding
Basic and diluted (in shares)	3,876	630

Note 5 - Fair Value Measurements - Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - Fair Value, Recurring [Member] - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Total Assets	$ 3,532	$ 4,212
Fair Value, Inputs, Level 1 [Member]
Total Assets	3,532	4,212
Money Market Funds [Member]
Cash equivalents	3,532	4,212
Money Market Funds [Member] \| Fair Value, Inputs, Level 1 [Member]
Cash equivalents	$ 3,532	$ 4,212

Note 12 - Stock Options and Stock-based Employee Compensation - Stock Options and Restricted Stock Units (RSUs) Outstanding and Available for Future Issuance (Details) - shares shares in Thousands	Dec. 31, 2023	Dec. 31, 2022
Stock Options and RSUs Outstanding (in shares)	424	89
The 2020 Equity Incentive Plan [Member]
Stock Options and RSUs Outstanding (in shares)	393	50
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant (in shares)	339	12
The 2011 Long-term Incentive Plan [Member]
Stock Options and RSUs Outstanding (in shares)	29	30
Non-Plan [Member]
Stock Options and RSUs Outstanding (in shares)	2	9

Note 7 - Accrued Expenses

12 Months Ended

Dec. 31, 2023

Accounts Payable, Accrued Liabilities, and Other Liabilities Disclosure, Current [Text Block]

Note 7 – Accrued Expenses

Accrued expenses are comprised of the following:

	December 31,
(in thousands)	2023		2022

Research and development	$	574	$	786
Professional fees		279		459
Severance		261		-
Salaries, bonus and benefits		64		123
Other		440		184
Total accrued expenses	$	1,618	$	1,552

Note 3 - Going Concern and Management's Plans (Details Textual) - USD ($) $ in Thousands	3 Months Ended				12 Months Ended
	Mar. 31, 2024	Dec. 31, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2023	Dec. 31, 2022	Apr. 02, 2024
Net Income (Loss) Attributable to Parent					$ (20,291)	$ (39,208)
Goodwill, Impairment Loss			$ 2,600	$ 500	3,058	12,624
Impairment of Intangible Assets (Excluding Goodwill), Total					0	6,820
Deferred Income Tax Expense (Benefit), Total					0	(1,367)
Retained Earnings (Accumulated Deficit)		$ (844,823)			(844,823)	(824,532)
Proceeds from Issuance of Common Stock					755	4,253
Cash and Cash Equivalents, at Carrying Value		4,319			4,319	6,172
Liabilities, Current		$ 3,996			$ 3,996	$ 2,457
Forecast [Member] \| Senior Convertible Notes [Member]
Convertible Debt							$ 1,500
ATM Program [Member]
Stock Issued During Period, Shares, New Issues (in shares)		848,367				206,824
Proceeds from Issuance of Common Stock		$ 800				$ 4,300
ATM Program [Member] \| Forecast [Member]
Stock Issued During Period, Shares, New Issues (in shares)	2,576,153
Proceeds from Issuance of Common Stock	$ 1,400
ATM Program [Member] \| Subsequent Event [Member]
Stock Issued During Period, Shares, New Issues (in shares)	2,576,153
Proceeds from Issuance of Common Stock	$ 1,400
Rostafuroxin Drug Candidate [Member]
Impairment of Intangible Assets (Excluding Goodwill), Total						6,800
Deferred Income Tax Expense (Benefit), Total						$ (1,400)

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Cash flows from operating activities:
Net loss	$ (20,291)	$ (39,208)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	82	533
Stock-based compensation	1,278	3,086
Non-cash lease expense	409	528
Loss on impairment of goodwill	3,058	12,624
Loss on impairment of intangible assets	0	6,820
Loss on sale and disposal of property and equipment	12	19
Deferred income tax benefit	0	(1,367)
Unrealized gain on foreign exchange rate changes	(3)	(710)
Changes in assets and liabilities:
Prepaid expenses and other current assets	923	1,076
Accounts payable	560	(444)
Accrued expenses	66	(1,838)
Operating lease liabilities	(431)	(571)
Other current liabilities	900	0
Net cash used in operating activities	(13,437)	(19,452)
Cash flows from investing activities:
Proceeds from sale of property and equipment	0	210
Purchase of property and equipment	(15)	(13)
Net cash (used in) provided by investing activities	(15)	197
Cash flows from financing activities:
Proceeds from issuance of common stock and warrants, net of issuance costs	10,794	0
Proceeds from exercise of common stock warrants, net of expenses	843	0
Proceeds from ATM Program, net of issuance costs	755	4,253
Principal payments on loans payable	(797)	(1,174)
Net cash provided by financing activities	11,595	3,079
Net decrease in cash, cash equivalents, and restricted cash	(1,857)	(16,176)
Cash, cash equivalents, and restricted cash - beginning of year	6,326	22,502
Cash, cash equivalents, and restricted cash - end of year	4,469	6,326
Supplementary disclosure of non-cash activity:
Prepayment of insurance through third-party financing	778	1,132
January 2023 Existing Warrants [Member]
Supplementary disclosure of non-cash activity:
Fair value of warrant modifications related to the warrant exercise inducement	1,238	0
February 2023 Existing Warrants [Member]
Supplementary disclosure of non-cash activity:
Fair value of warrant modifications related to the warrant exercise inducement	$ 274	$ 0

Note 9 - Other Current Liabilities (Details Textual) - License Agreement with Philip Morris USA for Aerosolization Technology [Member] - USD ($)	Jul. 01, 2024	Jan. 19, 2024	Jan. 18, 2024	Jan. 17, 2024	Dec. 31, 2023
Licensing Agreement Accrued Payments					$ 900,000
Forecast [Member]
License Agreement, Fee	$ 400,000
Subsequent Event [Member]
License Agreement, Fee	$ 325,000	$ 75,000	$ 100,000
License Agreement, Maximum Milestone Payments				$ 1,400,000

Note 14 - Related Party Transactions

12 Months Ended

Dec. 31, 2023

Note 14 – Related Party Transactions

Lee’s Holdings

As of December 31, 2023 and 2022, Lee’s Holdings’ beneficial ownership of our issued and outstanding shares of common stock was 2% and 13%, respectively.

We entered into the following transactions with Lee’s Holdings during 2023 and 2022:

	●	On August 17, 2022, we entered into the A&R License Agreement, with Lee’s (HK) and Zhaoke, effective as of August 9, 2022. We may receive up to $78.9 million in potential clinical, regulatory, and commercial milestone payments under the A&R License Agreement. We are also entitled to receive a low double-digit percentage of Licensee’s non-royalty sublicense income (See the section titled, “Note 13 – Collaboration, Licensing and Research Funding Agreements – Lee’s Pharmaceutical (HK) Ltd.)”);

	●	In March 2020, we entered into the Term Sheet with Lee’s (HK), pursuant to which Lee’s (HK) had agreed to provide financing for the development of AEROSURF. In August 2020, we entered into the PF Agreement with Lee’s (HK), formalizing the terms of the Term Sheet, under which we received payments of $1.0 million in 2021. As of December 31, 2023 and 2022, the liability balance related to the payments under the PF Agreement was $3.8 million and is recorded in other liabilities. The liability will remain on the balance sheet until we repay such amounts as a result of any revenues and payments received by us for any sale, divestiture, license or other development and/or commercialization of the KL4/AEROSURF patent portfolio. No further amounts are due under the PF Agreement as of December 31, 2023 (See the section titled, “Note 13 – Collaboration, Licensing and Research Funding Agreements – Lee’s Pharmaceutical (HK) Ltd.)”); and

●

During 2022, we incurred $0.4 million in research and development expenses for services provided by an affiliate of Lee’s Holdings, $0.3 million of which was in accrued expenses as of December 31, 2022.

Panacea Venture Management Company Ltd.

As of December 31, 2023 and 2022, Panacea Venture Management Company Ltd.’s, or Panacea’s, beneficial ownership of our issued and outstanding shares of common stock was 1% and 9%, respectively.

James Huang is a founding and Managing Partner of Panacea. In connection with the CVie Acquisition in December 2018, Mr. Huang was appointed as a director and Chairman of our Board. In April 2023, Mr. Huang resigned from this position.

On February 21, 2023, we entered into a warrant exercise inducement offer letter with Panacea Venture Healthcare Fund I, L.P., a related party of Panacea and a holder of certain of the February 2023 Existing Warrants. Pursuant to the terms of the inducement letter, we agreed to amend the February 2023 Existing Warrants by lowering the exercise price of the February 2023 Existing Warrants to $7.06 per share. Additionally, Panacea agreed to exercise for cash all of their February 2023 Existing Warrants to purchase an aggregate of 22,246 shares of common stock in exchange for our agreement to issue to Panacea new warrants to purchase up to an aggregate of 44,492 shares of common stock. We received aggregate gross and net proceeds of approximately $0.2 million and $0.1 million, respectively, from the exercise of the February 2023 Existing Warrants by Panacea (See the section titled, “Note 11 – Mezzanine Equity and Stockholders’ Equity”).

The entire disclosure for related party transactions. Examples of related party transactions include transactions between (a) a parent company and its subsidiary; (b) subsidiaries of a common parent; (c) and entity and its principal owners; and (d) affiliates.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480990/946-20-50-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
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-URI https://asc.fasb.org//1943274/2147480990/946-20-50-5

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480990/946-20-50-6

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 235
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481062/946-235-50-2

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 235
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481062/946-235-50-2

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 850
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-Name Accounting Standards Codification
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-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483326/850-10-50-1

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-07(2)(g)(3))
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Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
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Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
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-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-07(2)(e))
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-URI https://asc.fasb.org//1943274/2147483575/946-220-S99-1

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 850
-Name Accounting Standards Codification
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-URI https://asc.fasb.org//850/tableOfContent

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 850
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-Name Accounting Standards Codification
-Section 50
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-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483326/850-10-50-6

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 850
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483326/850-10-50-1

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 850
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483326/850-10-50-1

+ Details

Note 6 - Property and Equipment (Tables)

12 Months Ended

Dec. 31, 2023

Property, Plant and Equipment [Table Text Block]

	December 31,
(in thousands)	2023			2022

Leasehold improvements	$	2,664		$	2,649
Manufacturing, laboratory & office equipment		870			881
Furniture & fixtures		390			390
Subtotal		3,924			3,920
Accumulated depreciation and amortization		(3,741	)		(3,658	)
Property and equipment, net	$	183		$	262

Note 12 - Stock Options and Stock-based Employee Compensation

12 Months Ended

Dec. 31, 2023

Share-Based Payment Arrangement [Text Block]

Note 12 – Stock Options and Stock-based Employee Compensation

Long-term Incentive Plans

On November 23, 2020, our Board of Directors adopted our 2020 Plan, which was subsequently approved on December 24, 2020 by written consent of our majority stockholders and became effective on January 20, 2021, or the Effective Date. On the Effective Date, the 2020 Plan replaced our 2011 long-term incentive plan, or the 2011 Plan, and the 2020 Plan became our primary plan for providing equity-based compensation to our eligible employees, consultants, and non-employee directors. Awards under the 2020 Plan may include stock options, stock appreciation rights, or SARs, restricted stock awards, or RSAs, restricted stock units, or RSUs, other performance and stock-based awards, and dividend equivalents.

On August 15, 2023, at the Annual Meeting of Stockholders, our stockholders approved an amendment and restatement of the 2020 Plan to increase the authorized shares under the existing 2020 Plan by 645,000 shares and to remove the 2020 Plan’s evergreen provision.

As of December 31, 2023, there were approximately 0.7 million shares of our common stock authorized under the 2020 Plan, of which approximately 0.3 million shares remained available for issuance as of December 31, 2023.

An administrative committee, currently the Compensation Committee of the Board of Directors, or Committee delegates, may determine the types, the number of shares covered by, and the terms and conditions of, such awards. Eligible participants may include any of our employees, directors, advisors or consultants.

Stock options and RSUs outstanding and available for future issuance are as follows:

	December 31,
(in thousands)	2023		2022

Stock Options and RSUs Outstanding
2020 Plan		393		50
2011 Plan		29		30
Non-Plan		2		9
Total Outstanding		424		89

Available for Future Grants under the 2020 Plan		339		12

No SARs, RSAs, other performance and stock-based awards, or dividend equivalents have been granted under the 2020 Plan. Although individual grants may vary, option awards generally have a 10-year term, are exercisable upon vesting, and vest with respect to one-twelfth of the total number of shares subject to the options on a quarterly basis (every three months) or vest with respect to one-third of the total number of shares subject to the options on an annual basis (every twelve months). Non-Plan stock options outstanding are in connection with the hiring of certain executive officers and other employees for whom inducement grants were awarded in accordance with Nasdaq Listing Rule 5635(c)(4). The inducement grants vest in a series of three successive, equal installments beginning with the first anniversary of the grant date and have a 10-year term. Although individual awards may vary, RSUs generally vest with respect to one-third of the total number of shares subject to the RSUs on an annual basis (every twelve months).

A summary of activity under our long-term incentive plans is presented below:

(in thousands, except for weighted-average data)
Stock Options	Shares			Weighted-Average Exercise Price		Weighted-Average Remaining Contractual Term (In Years)

Outstanding at January 1, 2023		78		$	381.00
Granted		213			1.21
Forfeited or expired		(14	)		259.02
Outstanding at December 31, 2023		277		$	92.41		8.8

Vested and exercisable at December 31, 2023		56		$	432.45		5.9

Vested and expected to vest at December 31, 2023		254		$	94.53		8.8

(in thousands, except for weighted-average data)
Restricted Stock Units	Shares			Weighted- Average Grant Date Fair Value

Outstanding at January 1, 2023		11		$	49.50
Awarded		142			1.21
Vested		(3	)		48.55
Cancelled		(3	)		49.57
Outstanding at December 31, 2023		147		$	2.94

Based upon application of the Black-Scholes option-pricing formula described below, the weighted-average grant-date fair value of options granted during the years ended December 31, 2023 and 2022 was $1.03 and $42.00, respectively. The weighted-average grant-date fair value of RSUs granted during the years ended December 31, 2023 and 2022 was $1.21 and $49.50, respectively. The total intrinsic value of options outstanding, vested, and exercisable as of December 31, 2023 are each $0.

Stock-Based Compensation

We recognized stock-based compensation expense in accordance with ASC Topic 718 of $1.3 million and $3.1 million, respectively, for the years ended December 31, 2023 and 2022.

Stock-based compensation expense was classified as follows:

	Year Ended December 31,
(in thousands)	2023		2022

Research and development	$	383	$	807
General and administrative		895		2,279
Total	$	1,278	$	3,086

The fair value of each option award is estimated on the grant date using the Black-Scholes option-pricing formula that uses assumptions noted in the following table. Expected volatilities are based upon the historical volatility of our common stock and other factors. We also use historical data and other factors to estimate option exercises, employee terminations and forfeiture rates. The risk-free interest rates are based upon the U.S. Treasury yield curve in effect at the time of the grant.

	Year Ended December 31,
	2023			2022

Weighted average expected volatility		112	%		106	%
Weighted average expected term		6.0			6.9
Weighted average risk-free interest rate		4.33	%		1.70	%
Expected dividends		-			-

The total fair value of the underlying shares of the options vested during 2023 and 2022 is $2.8 million and $3.8 million, respectively. As of December 31, 2023, there was $0.6 million of total unrecognized compensation cost related to non-vested share-based compensation arrangements granted under the 2020 Plan and the 2011 Plan. That cost is expected to be recognized over a weighted-average vesting period of 2.1 years.

Note 1 - The Company and Description of Business

12 Months Ended

Dec. 31, 2023

Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]

Note 1 – The Company and Description of Business

We are a biotechnology company focused on advancing early and late-stage innovative therapies for critical conditions and diseases. Our portfolio of product candidates includes istaroxime, a Phase 2 candidate with sarco endoplasmic reticulum Ca2+ -ATPase 2a, or SERCA2a, activating properties for acute heart failure and associated cardiogenic shock, preclinical SERCA2a activators for heart failure, rostafuroxin for the treatment of hypertension in patients with a specific genetic profile, and a preclinical atypical protein kinase C iota, or aPKCi, inhibitor (topical and oral formulations), being developed for potential application in rare and broad oncology indications. We also have a licensing business model with partnership out-licenses currently in place.

Our lead product candidate, istaroxime, is a first-in-class, dual-acting agent being developed to increase blood pressure and improve cardiac function in patients with cardiogenic shock and to improve cardiac function in patients with acute heart failure, or AHF, and reverse the hypotension and hypoperfusion associated with heart failure that deteriorates to cardiogenic shock. Istaroxime demonstrated significant improvement in both systolic and diastolic aspects of cardiac function and was generally well tolerated in three Phase 2 clinical trials. Istaroxime has been granted Fast Track designation for the treatment of AHF by the U.S. Food and Drug Administration, or FDA. Based on the profile observed in our Phase 2 clinical studies in AHF, where istaroxime significantly improved cardiac function and systolic blood pressure, or SBP, in acute decompensated heart failure patients and had a favorable renal profile, we initiated a Phase 2 global clinical study, or the SEISMiC Study, to evaluate istaroxime for the treatment of early cardiogenic shock (Society for Cardiovascular Angiography and Interventions, or SCAI, Stage B shock), a severe form of AHF characterized by very low blood pressure and risk for hypoperfusion to critical organs and mortality. In April 2022, we announced our observations in the SEISMiC Study that istaroxime rapidly and significantly increased SBP while also improving cardiac function and preserving renal function. We believe that istaroxime has the potential to fulfill an unmet need in early and potentially more severe cardiogenic shock. We further believe that the data from the SEISMiC Study supports continued development in both cardiogenic shock and AHF. In the fourth quarter of 2023, we initiated an extension to the SEISMiC Study, or the SEISMiC Extension, to evaluate a longer dosing period and to continue to characterize the effects of istaroxime, including activation of SERCA2a. The SEISMiC Extension study is expected to enroll up to 30 subjects with SCAI Stage B cardiogenic shock with data anticipated in the second half of 2024. Additionally, we have recently initiated a small study in more severe SCAI Stage C cardiogenic shock, or SEISMiC C, to evaluate the safety and efficacy of istaroxime in cardiogenic shock patients who are also receiving standard of care rescue therapy for shock. The SEISMiC C study is expected to enroll up to 20 subjects with SCAI Stage C cardiogenic shock with enrollment anticipated to be completed in late 2024. Our ability to complete both of these studies with their intended sample size is dependent upon us securing adequate resourcing for the program through financing efforts or business development activities.

Our heart failure cardiovascular portfolio also includes SERCA2a activators. This research program is evaluating these preclinical product candidates, including oral and intravenous SERCA2a activator heart failure compounds. These candidates would potentially be developed for both acute decompensated and chronic out-patient heart failure. In addition, our cardiovascular drug product candidates include rostafuroxin, a novel product candidate for the treatment of hypertension in patients with a specific genetic profile. We are pursuing potential licensing arrangements and/or other strategic partnerships and do not intend to advance rostafuroxin without securing such an arrangement or partnership.

Our cardiovascular assets and programs are associated with a regional licensed partnership with Lee’s Pharmaceutical (HK) Ltd., or Lee’s (HK), for the development and commercialization of our product candidate, istaroxime, in Greater China. In addition to istaroxime, the agreement also licenses our preclinical next-generation SERCA2a activators, known as dual mechanism SERCA2a activators, and rostafuroxin, a Phase 2 product candidate for hypertension associated with specific genotypes. In addition, we are supporting the efforts of Lee’s (HK) in starting a Phase 3 trial in AHF with istaroxime. Further, we are engaged in discussions regarding potential global licensing partnerships outside of Lee’s (HK) territory.

On April 2, 2024, we entered into an Asset Purchase Agreement, or the Asset Purchase Agreement, with Varian Biopharmaceuticals, Inc., or Varian. Pursuant to the Asset Purchase Agreement, we purchased all of the assets of Varian’s business associated with a Licence Agreement, dated as of July 5, 2019, by and between Varian and Cancer Research Technology Limited, or the Licence Agreement, including the Licence Agreement, all rights in molecules and compounds subject to the Licence Agreement, know-how and inventory of drug substance, or the Transferred Assets. The Transferred Assets include a novel, potential high-potency, specific, aPKCi with possible broad use in oncology as well as certain rare malignant diseases. The asset platform includes two formulations (topical and oral) of an aPKCi inhibitor. We plan to advance investigational new drug, or IND, enabling activities and are in the process of determining the expected clinical development plan for the platform.

Our ability to advance our development programs is dependent upon our ability to secure additional capital in both the near and long-term, through public or private securities offerings; convertible debt financings; and/or potential strategic opportunities, including licensing agreements, drug product development, and marketing collaboration arrangements, pharmaceutical research cooperation arrangements, and/or other similar transactions in geographic markets, including the U.S., and/or through potential grants and other funding commitments from U.S. government agencies, in each case, if available. We have engaged with potential counterparties in various markets and will continue to pursue non-dilutive sources of capital as well as potential private and public securities offerings. There can be no assurance, however, that we will be able to identify and enter into public or private securities offerings on acceptable terms and in amounts sufficient to meet our needs or qualify for non-dilutive funding opportunities under any grant programs sponsored by U.S. government agencies, private foundations, and/or leading academic institutions, or identify and enter into any strategic transactions that will provide the additional capital that we will require. If none of these alternatives is available, or if available and we are unable to raise sufficient capital through such transactions, we potentially could be forced to limit or cease our development activities, which would have a material adverse effect on our business, financial condition, and results of operations.

Note 8 - Loans Payable

12 Months Ended

Dec. 31, 2023

Short-Term Debt [Text Block]

Note 8 - Loans Payable

In June 2023, we entered into an insurance premium financing and security agreement with IPFS Corporation. Under the agreement, we financed $0.8 million of certain premiums at a 7.24% fixed annual interest rate. Payments of approximately $126,000 are due monthly from July 2023 through April 2024. As of December 31, 2023, the outstanding principal of the loan was $0.2 million.

In June 2022, we entered into an insurance premium financing and security agreement with Bank Direct Capital Finance. Under the agreement, we financed $1.1 million of certain premiums at a 3.90% fixed annual interest rate. Payments of approximately $126,000 were due monthly from July 2022 through March 2023. As of December 31, 2022, the outstanding principal of the loan was $0.3 million. The balance of the loan was repaid during the first quarter of 2023.

Note 15 - Litigation

12 Months Ended

Dec. 31, 2023

Legal Matters and Contingencies [Text Block]

Note 15 – Litigation

We are not aware of any pending or threatened legal actions that would, if determined adversely to us, have a material adverse effect on our business and operations.

We have from time to time been involved in disputes and proceedings arising in the ordinary course of business, including in connection with the conduct of our clinical trials. In addition, as a public company, we are also potentially susceptible to litigation, such as claims asserting violations of securities laws. Any such claims, with or without merit, if not resolved, could be time-consuming and result in costly litigation. There can be no assurance that an adverse result in any future proceeding would not have a potentially material adverse effect on our business, results of operations and financial condition.

Note 12 - Stock Options and Stock-based Employee Compensation - Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Share-Based Payment Arrangement, Expense	$ 1,278	$ 3,086
Research and Development Expense [Member]
Share-Based Payment Arrangement, Expense	383	807
Selling, General and Administrative Expenses [Member]
Share-Based Payment Arrangement, Expense	$ 895	$ 2,279

Note 18 - Subsequent Events (Details Textual) - USD ($)						12 Months Ended
Note 18 - Subsequent Events (Details Textual) - USD ($)	Jan. 24, 2025	Apr. 03, 2024	Apr. 02, 2024	Jan. 24, 2024	Jan. 12, 2024	Jan. 24, 2025	Dec. 31, 2023	Dec. 31, 2022	Nov. 17, 2022
Common Stock, Par or Stated Value Per Share (in dollars per share)							$ 0.001	$ 0.001
Preferred Stock, Par or Stated Value Per Share (in dollars per share)							$ 0.001	$ 0.001	$ 0.001
Forecast [Member] \| Senior Convertible Notes [Member]
Convertible Debt			$ 1,500,000
Debt Instrument, Convertible, Conversion Price (in dollars per share)			$ 0.3603
Debt Instrument, Interest Rate, Stated Percentage			10.00%
Debt Instrument Interest Rate Default Percentage			18.00%
Forecast [Member] \| Minimum [Member] \| Senior Convertible Notes [Member]
Debt Instrument, Convertible, Conversion Price (in dollars per share)			$ 0.0721
Forecast [Member] \| Asset Purchase Agreement With Varian Biopharmaceuticals, Inc. [Member]
Asset Purchase Agreement, Contingent Consideration			$ 2.3
Forecast [Member] \| Series B Preferred Stock [Member]
Stock Issued During Period, Shares, New Issues (in shares)			5,500
Preferred Stock, Par or Stated Value Per Share (in dollars per share)		$ 1,000	$ 0.001
Stock Issuance Agreement, Shares Authorized (in shares)		5,500
Preferred Stock, Convertible, Conversion Price (in dollars per share)		$ 0.3603
Stock Issuance Agreement, Amount Authorized		$ 5,500,000
Convertible Preferred Stock, Shares Issued upon Conversion (in shares)		15,265
Preferred Stock, Dividend Rate, Percentage		10.00%
Preferred Stock Dividend Rate Triggering Event Percentage		18.00%
Forecast [Member] \| Series B Preferred Stock [Member] \| Minimum [Member]
Preferred Stock, Convertible, Conversion Price (in dollars per share)		$ 0.0721
Exchange and Termination Agreement with Deerfield Management Company, L.P. [Member] \| Forecast [Member]
Payments for Exchange and Termination Agreement	$ 100,000					$ 200,000
Subsequent Event [Member] \| License Agreement with Lee’s Pharmaceutical (HK) Ltd. [Member]
Maximum Amount May be Received for Potential Milestone Payments					$ 3,100,000
Maximum Amount May be Received for Sales Milestone Payments					$ 135,250,000
Royalties to be Received, Period After First Commercial Sale (Year)					10 years
Royalty Rate Reduction Percentage					50.00%
Subsequent Event [Member] \| Exchange and Termination Agreement with Deerfield Management Company, L.P. [Member]
Exchange and Termination Agreement, Maximum Potential Millstone Payments				$ 15,000,000
Payments for Exchange and Termination Agreement				$ 100,000
Stock Issued During Period, Shares, New Issues (in shares)				608,272
Common Stock, Par or Stated Value Per Share (in dollars per share)				$ 0.001

Note 4 - Accounting Policies

12 Months Ended

Dec. 31, 2023

Significant Accounting Policies [Text Block]

Note 4 – Accounting Policies

Principles of Consolidation

The consolidated financial statements are prepared in accordance with US GAAP and include accounts of Windtree Therapeutics, Inc. and our wholly owned subsidiary, CVie Investments Limited and its wholly owned subsidiary, CVie Therapeutics Limited, or CVie Therapeutics, and a presently inactive subsidiary, Discovery Laboratories, Inc. (formerly known as Acute Therapeutics, Inc.).

Intangible Assets and Goodwill

We record acquired intangible assets and goodwill based on estimated fair value. The identifiable intangible assets resulting from the CVie Therapeutics acquisition in December 2018 relate to in-process research and development, or IPR&D, of istaroxime and rostafuroxin. The IPR&D assets are considered indefinite-lived intangible assets until completion or abandonment of the associated research and development efforts. IPR&D is not amortized but reviewed for impairment at least annually, or when events or changes in the business environment indicate the carrying value may be impaired.

When testing our indefinite-lived intangible assets and goodwill for impairment, we can elect to perform a qualitative assessment to determine if it is more likely than not that the fair values of our indefinite-lived intangible assets and our reporting unit are less than their respective carrying values. Such qualitative factors can include, among others, industry and market conditions, overall financial performance, and relevant entity-specific events. If we conclude based on our qualitative assessment that it is more likely than not that the fair value of our indefinite-lived intangible assets or reporting unit are less than their respective carrying values, we perform a quantitative assessment. When conducting our annual impairment test of indefinite-lived intangible assets and goodwill as of December 1, 2023 and 2022, we elected to perform a quantitative assessment.

When performing the quantitative impairment assessment for our indefinite-lived IPR&D intangible assets, we estimate the fair values of the assets using the multi-period excess earnings method, or MPEEM. MPEEM is a variation of the income approach which estimates the fair value of an intangible asset based on the present value of the incremental after-tax cash flows attributable to the intangible asset. Significant factors considered in the calculation of IPR&D intangible assets include the risks inherent in the development process, including the likelihood of achieving commercial success and the cost and related time to complete the remaining development. Future cash flows for each project were estimated based on forecasted revenue and costs, taking into account the expected product life cycles, market penetration, and growth rates. Other significant estimates and assumptions inherent in this approach include (i) the amount and timing of the projected net cash flows associated with the IPR&D assets, (ii) the discount rate, which seeks to reflect the various risks inherent in the projected cash flows; and (iii) the tax rate, which considers geographic diversity of the projected cash flows. While we use the best available information to prepare our cash flows and discount rate assumptions, actual future cash flows could differ significantly based on the commercial success of the related drug candidates and market conditions which could result in future impairment charges related to our indefinite-lived intangible asset balances.

Based on our annual quantitative impairment assessment of our indefinite-lived IPR&D intangible assets as of December 1, 2023, we concluded that the assets were not impaired.

As part of our annual quantitative impairment assessment of indefinite-lived IPR&D intangible assets as of December 1, 2022, we reassessed certain assumptions related to our rostafuroxin drug candidate due to the continued difficulties in current macroeconomic conditions which have continued to make it more challenging to secure the funding needed to conduct the additional Phase 2 clinical trial and have therefore further delayed our intended development of rostafuroxin. As a result, we concluded that the fair value of the IPR&D related to our rostafuroxin drug candidate was less than its carrying value. We estimated the fair value of the asset using MPEEM and determined that the fair value as of December 1, 2022 was approximately $2.9 million. We then compared this fair value to the carrying value of approximately $9.7 million, and recorded an additional loss on impairment of intangible assets of $6.8 million related to the IPR&D of our rostafuroxin drug candidate. We also reassessed the assumptions related to the fair value of the IPR&D related to our istaroxime drug candidate. The estimated fair value exceeded the carrying value of that asset. As a result, no impairment charge was recognized related to the IPR&D of our istaroxime drug candidate.

Goodwill represents the excess of the purchase price over the fair value of assets acquired and liabilities assumed in a business combination and is not amortized. It is reviewed for impairment at least annually or when events or changes in the business environment indicate that its carrying value may be impaired. Our company consists of one reporting unit. In order to perform the quantitative goodwill impairment test, we compare the estimated fair value of our reporting unit to its carrying value. If the fair value exceeds the carrying value, no further evaluation is required, and no impairment exists. If the carrying value exceeds the fair value, the difference between the carrying value and the fair value is recorded as an impairment loss, the amount of which may not exceed the total amount of goodwill. When performing a goodwill impairment assessment, we estimate the fair value of our reporting unit, including the use of the quoted market price and related market capitalization of our common stock, adjusted for an estimated control premium based on transactions completed by comparable companies.

In accordance with applicable accounting standards, we are required to review intangible assets and goodwill for impairment on an annual basis, or more frequently where there is an indication of impairment. Throughout the year, we consider whether any events or changes in the business environment have occurred which indicate that goodwill may be impaired. For example, a significant decline in the closing share price of our common stock and market capitalization may suggest that the fair value of our reporting unit has fallen below its carrying value, indicating that an interim goodwill impairment test is required. Accordingly, we monitor changes in our share price during interim periods between annual impairment tests and consider overall stock market conditions, the underlying reasons for the decline in our share price, the significance of the decline, and the duration of time that our securities have been trading at a lower value.

Since early 2022, we have experienced a declining trend in the closing share price of our common stock, on a split-adjusted basis. As a result, we performed the required interim goodwill impairment test in the second and third quarters of 2022 as well as the annual goodwill quantitative test as of December 1, 2022 and determined that the fair value of our reporting unit was more likely than not less than its carrying value. For the year ended December 31, 2022, we recorded an aggregate loss on goodwill of $12.6 million within operating expenses in our consolidated statement of operations.

During each of the first and second quarters of 2023, the continued declining trend in the closing share price of our common stock, on a split-adjusted basis, suggested that the fair value of our reporting unit was more likely than not less than its carrying value. As a result, in each quarter, we performed the required interim goodwill impairment test consistent with the methodology described above and determined that the fair value of our reporting unit was more likely than not less than its carrying value. We recorded a loss on impairment of goodwill of $0.5 million in the first quarter of 2023 and an additional loss of $2.6 million, representing the remaining balance of goodwill, in the second quarter of 2023. For the year ended December 31, 2023, the aggregate loss on impairment of goodwill was $3.1 million, recognized within operating expenses in our consolidated statement of operations. As of December 31, 2023, goodwill was zero on our consolidated balance sheet.

The following table represents identifiable intangible assets and goodwill as of December 31, 2023 and 2022:

	December 31,
(in thousands)	2023		2022

Istaroxime drug candidate	$	22,340	$	22,340
Rostafuroxin drug candidate		2,910		2,910
Intangible assets		25,250		25,250

Goodwill	$	-	$	3,058

Foreign Currency Transactions

The functional currency for our foreign subsidiaries is the US Dollar. We remeasure monetary assets and liabilities that are not denominated in the functional currency at exchange rates in effect at the end of each period. Gains and losses from the remeasurement of foreign currency transactions are recognized in Total other income, net. Foreign currency transactions resulted in gains of $0.7 million for the year ended December 31, 2022. Foreign currency transactions for the year ended December 31, 2023 are immaterial.

Use of Estimates

The preparation of financial statements in conformity with US GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.

Cash and Cash Equivalents

Cash and cash equivalents are held at domestic and foreign financial institutions and consist of liquid investments and money market funds that are readily convertible into cash.

Concentration of Credit Risk

Financial instruments, which potentially subject us to credit risk, consist principally of cash and cash equivalents. All cash and cash equivalents are held in U.S. financial institutions and money market funds. At times, we may maintain cash balances in excess of the federally insured amount of $250,000 per depositor, per insured bank, for each account ownership category. Although we currently believe that the financial institutions with whom we do business will be able to fulfill their commitments to us, there is no assurance that those institutions will be able to continue to do so. We have not experienced any credit losses associated with our balances in such accounts.

Fair Value of Financial Instruments

Our financial instruments consist principally of cash and cash equivalents and restricted cash. The fair values of our cash equivalents are based on quoted market prices. The carrying value of cash equivalents is equal to their respective fair values at December 31, 2023 and 2022, respectively. Accounts payable and accrued expenses are carried at cost, which approximates fair value because of their short maturity. The carrying value of loans payable (including current installments) approximates fair value based on a comparison of interest rates on the loan to current market rates considering our credit risk.

Property and Equipment

Property and equipment are recorded at cost and depreciated using the straight-line method over the estimated useful lives of the assets (generally three to ten years). Leasehold improvements are amortized over the shorter of the estimated useful lives or the remaining term of the lease. Repairs and maintenance costs are charged to expense as incurred.

Restricted Cash

Restricted cash consists principally of a $140,000 certificate of deposit held by our bank as collateral for a letter of credit in the same notional amount held by our landlord to secure our obligations under our lease agreement dated May 26, 2004 for our headquarters location in Warrington, Pennsylvania and $10,000 in deposits held by our landlord for our offices in Taipei, Taiwan.

Leases

Leases are accounted for under Financial Accounting Standards Board, or FASB, Accounting Standards Codification, or ASC, Topic 842, Leases, or ASC 842. At the inception of an arrangement, we determine whether an arrangement is, or contains, a lease based on the unique facts and circumstances present in the arrangement. An arrangement is, or contains, a lease if the arrangement conveys the right to control the use of an identified asset for a period of time in exchange for consideration. Leases with a term greater than one year are generally recognized on the balance sheet as operating lease right-of-use assets and current and non-current operating lease liabilities, as applicable. It is our policy not to recognize on the balance sheet leases with terms of 12 months or less. We typically only include the initial lease term in our assessment of a lease arrangement. Options to extend a lease are not included in our assessment unless there is reasonable certainty that we will renew.

Operating lease liabilities and their corresponding operating lease right-of-use assets are recorded based on the present value of lease payments over the expected remaining lease term. Certain adjustments to the right-of-use asset may be required for items such as incentives received. The interest rate implicit in our leases is typically not readily determinable. As a result, we utilize our incremental borrowing rate, which reflects the fixed rate at which we could borrow on a collateralized basis the amount of the lease payments in the same currency, for a similar term, in a similar economic environment.

At the inception of a contract, we assess whether the contract is, or contains, a lease. The assessment is based on: (i) whether the contract involves the use of a distinct identified asset, (ii) whether we obtain the right to substantially all the economic benefit from the use of the asset throughout the period, and (iii) whether we have the right to direct the use of the asset.

We evaluate the classification of our leases as either finance leases or operating leases. A lease is classified as a finance lease if any one of the following criteria are met: the lease transfers ownership of the asset by the end of the lease term, the lease contains an option to purchase the asset that is reasonably certain to be exercised, the lease term is for a major part of the remaining useful life of the asset, the present value of the lease payments equals or exceeds substantially all of the fair value of the asset, or the leased asset is of such a specialized nature that it is expected to have no alternative use to the lessor at the end of the lease. A lease is classified as an operating lease if it does not meet any of these criteria. Currently, all of our leases are classified as operating leases.

Lease cost for our operating leases is recognized on a straight-line basis over the lease term. Included in lease cost are any variable lease payments incurred in the period that are not included in the initial lease liability and lease payments incurred in the period for any leases with an initial term of 12 months or less.

Long-lived Assets

Our long-lived assets, primarily consisting of property and equipment, are reviewed for impairment when events or changes in circumstances indicate that the carrying value of an asset may not be recoverable, or its estimated useful life has changed significantly. When the undiscounted cash flows of an asset are less than its carrying value, an impairment is recorded and the asset is written down to estimated value. No impairment was recorded during the years ended December 31, 2023 and 2022 as management believes there are no circumstances that indicate that the carrying value of the assets will not be recoverable.

Collaborative Arrangements

We account for collaborative arrangements in accordance with applicable accounting guidance provided in ASC Topic 808, Collaborative Arrangements. See the section titled, “Note 13 – Collaboration, Licensing and Research Funding Agreements”

Severance

In July 2023, we entered into a separation agreement with an executive, which provides that the former employee will be entitled to receive (i) a severance amount equal to the sum of the employee’s base salary then in effect and (ii) subject to certain exceptions, a pro rata bonus commensurate with the bonus awarded to other contract executives for the year 2023, prorated for the number of days of the employee’s employment during 2023, and payable at the time that other contract executives are paid bonuses with respect to 2023. The severance amount related to the departure of this executive is approximately $0.5 million, which was recorded in general and administrative expense at the date of the separation, and will be paid ratably through July 2024. As of December 31, 2023, approximately $0.2 million was paid. The remaining liability as of December 31, 2023 is approximately $0.3 million and is included in accrued expenses.

In June 2023, we implemented certain reductions in headcount. The total severance cost for impacted employees is approximately $0.2 million, which was recorded in research and development expense at the date of the separations and will be paid ratably through December 2023. As of December 31, 2023, approximately $0.2 million of severance costs was paid. No further amounts were due as of December 31, 2023.

In January 2022, in order to focus our resources on the development of our istaroxime program, we began to reduce costs related to KL4 surfactant that were not already transferred to our licensee, Lee’s Pharmaceutical (HK) Ltd., or Lee’s (HK), and Zhaoke Pharmaceutical (Hefei) Co. Ltd., or Zhaoke, under the terms of our License, Development and Commercialization Agreement between us and Lee’s (HK) dated as of June 12, 2017, as amended, or the Original License Agreement. These costs included certain reductions in headcount dedicated to KL4 surfactant and the decommissioning of both our analytical and technical support laboratory, which previously conducted release testing of active pharmaceutical ingredients, or APIs, and supportive research for our lyophilized and aerosolized KL4 surfactant, and our medical device development laboratory, which was previously used to conduct development activities and testing for our aerosol delivery system, or ADS, technologies. In February 2022, management communicated its commitment to provide severance payments to impacted employees, provided that they remained employed with us through their expected termination dates. The total severance cost for impacted employees was approximately $0.4 million, which was accrued over the service periods of the employees and was paid ratably through September 2022. All amounts due were paid in 2022.

Restructured Debt Liability – Contingent Milestone Payment

In conjunction with the November 2017 restructuring and retirement of long-term debt (See the section titled, “Note 10 – Restructured Debt Liability”), we have established a $15.0 million long-term liability for contingent milestone payments potentially due under the Exchange and Termination Agreement dated as of October 27, 2017, or the Milestone Agreement, between ourselves and affiliates of Deerfield Management Company L.P., or Deerfield. The liability has been recorded at full value of the contingent milestones and will continue to be carried at full value until the milestones are achieved and paid or milestones are not achieved and the liability is written off as a gain on debt restructuring.

Research and Development

We account for research and development expense by the following categories: (a) product development and manufacturing, (b) clinical, medical, and regulatory operations, and (c) direct clinical and preclinical development programs. Research and development expense includes personnel, facilities, manufacturing and quality operations, pharmaceutical development, research, clinical, regulatory, other preclinical and clinical activities and medical affairs. Research and development costs are charged to operations as incurred in accordance with ASC Topic 730, Research and Development.

Stock-based Compensation

Stock-based compensation is accounted for under the fair value recognition provisions of ASC Topic 718, Stock Compensation, or ASC Topic 718. See the section titled, “Note 12 – Stock Options and Stock-based Employee Compensation,” for a detailed description of our recognition of stock-based compensation expense. The fair value of stock option grants is recognized evenly over the vesting period of the options or over the period between the grant date and the time the option becomes non-forfeitable by the employee, whichever is shorter.

Warrant Accounting

We account for common stock warrants in accordance with applicable accounting guidance provided in ASC Topic 815, Derivatives and Hedging – Contracts in Entity’s Own Equity, or ASC Topic 815, as either derivative liabilities or equity instruments depending on the specific terms of the warrant agreement.

Income Taxes

We account for income taxes in accordance with ASC Topic 740, Accounting for Income Taxes, or ASC Topic 740, which requires the recognition of deferred tax liabilities and assets for the expected future tax consequences of temporary differences between financial statement carrying amounts and the tax basis of assets and liabilities.

We use a recognition threshold and measurement attribute for the financial statement recognition and measurement of a tax position taken or expected to be taken in a tax return. Because we have never realized a profit, management has fully reserved the net deferred tax asset since realization is not assured.

For the year ended December 31, 2022, we recorded a deferred income tax benefit of $1.4 million. The deferred income tax benefit recorded relates solely to the reduction of the deferred tax liabilities as a result of the loss on impairment of intangible assets related to rostafuroxin for the year ended December 31, 2022.

Net Loss per Common Share

Basic net loss per common share is computed by dividing net loss by the weighted average number of common shares outstanding for the period. Diluted net loss per common share is computed by giving effect to all potentially dilutive securities outstanding for the period. For the years ended December 31, 2023 and 2022,the number of shares of common stock potentially issuable upon the exercise of certain stock options and warrants, as well as of the vesting of restricted stock units, was 5.4 million and 0.4 million shares, respectively. As of December 31, 2023 and 2022, all potentially dilutive securities were anti-dilutive and therefore have been excluded from the computation of diluted net loss per common share.

We do not have any components of other comprehensive (loss) income.

Concentration of Suppliers

We currently obtain the APIs of our drug products from a single supplier. In addition, our drug products are produced at one contract manufacturer. These single source providers also perform various studies as well as quality control release and stability testing and other activities related to our development and manufacturing activities. At the present time these providers are located outside of the U.S. The loss of either the supplier of our APIs or our drug product contract manufacturer could have a material adverse effect on our operations.

Segment and Geographic Information

We currently operate in one operating segment, which is the research and development of products focused on cardiovascular disease. We are managed and operated as one business. A single management team that reports to the Chief Executive Officer comprehensively manages the entire business. We do not operate separate lines of business with respect to our product candidates. We operate primarily in the U.S. and Asia. Long-lived assets, consisting of intangible assets of $25.3 million, were located outside the U.S. as of December 31, 2023.

Note 6 - Property and Equipment - Property and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Property and equipment, gross	$ 3,924	$ 3,920
Accumulated depreciation and amortization	(3,741)	(3,658)
Property and equipment, net	183	262
Leasehold Improvements [Member]
Property and equipment, gross	2,664	2,649
Manufacturing, Laboratory, and Office Equipment [Member]
Property and equipment, gross	870	881
Furniture and Fixtures [Member]
Property and equipment, gross	$ 390	$ 390

Note 12 - Stock Options and Stock-based Employee Compensation - Stock Options Valuation Assumptions (Details)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Weighted average expected volatility	112.00%	106.00%
Weighted average expected term (Year)	6 years	6 years 10 months 24 days
Weighted average risk-free interest rate	4.33%	1.70%

Note 4 - Accounting Policies (Details Textual) shares in Millions	1 Months Ended		3 Months Ended		12 Months Ended
	Jul. 31, 2023 USD ($)	Jun. 30, 2023 USD ($)	Jun. 30, 2023 USD ($)	Mar. 31, 2023 USD ($)	Dec. 31, 2023 USD ($) shares	Dec. 31, 2022 USD ($) shares	Nov. 01, 2017 USD ($)
Impairment of Intangible Assets (Excluding Goodwill), Total					$ 0	$ 6,820,000
Indefinite-Lived Intangible Assets (Excluding Goodwill), Fair Value Disclosure						2,900,000
Intangible Assets, Net (Excluding Goodwill), Total						9,700,000
Number of Reporting Units					1
Goodwill, Impairment Loss			$ 2,600,000	$ 500,000	$ 3,058,000	12,624,000
Goodwill		$ 0	$ 0		0	3,058,000
Foreign Currency Transaction Gain, before Tax						700,000
Severance Costs						400,000
Liability for Contingent Milestone Payment, Noncurrent					15,000,000	15,000,000
Deferred Income Tax Expense (Benefit), Total					$ 0	$ (1,367,000)
Number of Shares of Common Stock Potentially Issuable upon the Exercise of Stock Options and Warrants (in shares) \| shares					5.4	0.4
Number of Operating Segments					1
Non-US [Member]
Intangible Assets, Net (Excluding Goodwill), Total					$ 25,300,000
Deerfield Loan [Member] \| Exchange and Termination Agreement [Member] \| Deerfield Management, L.P. [Member]
Liability for Contingent Milestone Payment, Noncurrent							$ 15,000,000
Executive [Member]
Severance Costs	$ 500,000	$ 200,000			200,000
Severance Accrual					300,000
Restricted Cash for Headquarters in Warrington, Pennsylvania [Member]
Security Deposit					140,000
Restricted Cash for Offices in Taipei, Taiwan [Member]
Security Deposit					$ 10,000
Minimum [Member]
Property, Plant and Equipment, Useful Life (Year)					3 years
Maximum [Member]
Property, Plant and Equipment, Useful Life (Year)					10 years

Note 8 - Loans Payable (Details Textual) - USD ($)		6 Months Ended
Note 8 - Loans Payable (Details Textual) - USD ($)	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2023	Dec. 31, 2022
Loans Payable With IPFS Corporation [Member]
Debt Instrument, Face Amount	$ 800,000
Debt Instrument, Interest Rate, Stated Percentage	7.24%
Debt Instrument, Periodic Payment	$ 126,000
Loans Payable to Bank			$ 200,000
Loan payable to Bank Direct Capital Finance [Member] \| Loans Payable [Member]
Debt Instrument, Face Amount		$ 1,100,000
Debt Instrument, Interest Rate, Stated Percentage		3.90%
Debt Instrument, Periodic Payment		$ 126,000
Loans Payable to Bank				$ 300,000

Note 5 - Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2023

Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]

	Fair Value		Fair value measurement using
	December 31,
(in thousands)	2023		Level 1		Level 2		Level 3

Cash equivalents:
Money market funds	$	3,532	$	3,532	$	-	$	-
Total Assets	$	3,532	$	3,532	$	-	$	-

	Fair Value		Fair value measurement using
	December 31,
(in thousands)	2022		Level 1		Level 2		Level 3

Cash equivalents:
Money market funds	$	4,212	$	4,212	$	-	$	-
Total Assets	$	4,212	$	4,212	$	-	$	-

Fair Value Measurements, Nonrecurring [Table Text Block]

Fair Value

Fair value measurement using

December 31,

(in thousands)

2023

Level 1

Level 2

Level 3

Goodwill

	Fair Value		Fair value measurement using
	December 31,
(in thousands)	2022		Level 1		Level 2		Level 3

Intangible assets:
Rostafuroxin drug candidate	$	2,910	$	-	$	-	$	2,910

Goodwill	$	3,058	$	-	$	-	$	3,058

Note 16 - Income Taxes

12 Months Ended

Dec. 31, 2023

Income Tax Disclosure [Text Block]

Note 16 – Income Taxes

The components of the benefit for income taxes for the years ended December 31, 2023 and 2022 is as follows:

	December 31,
(in thousands)	2023		2022
Deferred expense (benefit):
Foreign	$	-	$	(1,367	)
Total deferred expense (benefit)		-		(1,367	)
Total income tax expense (benefit)	$	-	$	(1,367	)

The reconciliation of the income tax benefit computed at the federal statutory rates to our recorded tax benefit for the years ended December 31, 2023 and 2022 is as follows:

	December 31,
(in thousands)	2023			2022

Income tax benefit, statutory rates	$	(4,261	)	$	(8,521	)
State taxes on income, net of federal benefit		(625	)		903
Net operating loss expirations		5,875			3,485
Intangibles		613			2,561
Research and development tax credit		490			825
Foreign rate differential		37			196
Stock compensation		464			-
Employee related and other		(575	)		467
Change in state tax rates		23,993			-
Other		-			(17	)
Income tax expense / (benefit), statutory rates		26,011			(101	)
Valuation allowance		(26,011	)		(1,266	)
Income tax benefit, net	$	-		$	(1,367	)

The tax effects of temporary differences that give rise to deferred tax assets and deferred tax liabilities as of December 31, 2023 and 2022, are as follows:

	December 31,
(in thousands)	2023			2022

Long-term deferred assets:
Net operating loss carryforwards (federal and state)	$	158,926		$	185,591
Research and development tax credit		17,081			17,671
Compensation expense on stock		3,940			4,166
Other accrued		1,386			1,293
Capitalized R&D expenses		3,606			2,369
Depreciation		355			191
Total long-term deferred tax assets		185,294			211,281
Long-term deferred liabilities:
IPR&D		(5,058	)		(5,061	)
Total long-term deferred tax liabilities		(5,058	)		(5,061	)
Valuation allowance		(185,294	)		(211,281	)
Deferred tax liabilities, net	$	(5,058	)	$	(5,061	)

We are in a net deferred tax liability position as of December 31, 2023 and 2022. Because we have never realized a profit, management has fully reserved the net deferred tax asset since realization is not assured. It is our policy to classify interest and penalties recognized on uncertain tax positions as a component of income tax expense. There was neither interest nor penalties accrued as of December 31, 2023 and 2022, nor were any incurred in 2023 or 2022.

At December 31, 2023 and 2022, we had available carryforward net operating losses for federal tax purposes of $620.4 million and $637.4 million, respectively, research and development tax credit carryforward of $16.5 million and $17.0 million, respectively and orphan drug tax credit carryforwards of $0.6 million for both periods. Of the $620.4 million of federal net operating loss carryforwards, $101.1 million can be carried forward indefinitely. The remaining federal net operating loss, research and development tax credit carryforwards and orphan drug credit carryforward will continue to expire through 2042.

At December 31, 2023 and 2022, we had available carryforward losses of approximately $576.3 million and $593.3 million, respectively, for state tax purposes. Of the $576.3 million state tax carryforward losses, $575.3 million is associated with the state of Pennsylvania, with the remainder associated with the other five (5) states within which we have established tax nexus.

The Tax Cuts and Jobs Act resulted in significant changes to the treatment of research and development, or R&D, expenditures under Internal Revenue Code Section 174. For tax years beginning after December 31, 2021, taxpayers are required to capitalize and amortize all R&D expenditures that are paid or incurred in connection with their trade or business for tax purposes. Specifically, costs for U.S.-based R&D activities must be amortized over five years and costs for foreign R&D activities must be amortized over 15 years, both using a midyear convention. During the year ended December 31, 2023, we capitalized $5.4 million and $2.0 million of domestic and foreign R&D expenses, respectively.

Future realization of the tax benefits of existing temporary differences and net operating loss carryforwards ultimately depends on the existence of sufficient taxable income within the carryforward period. As of December 31, 2023 and 2022, we performed an evaluation to determine whether a valuation allowance was needed. We considered all available evidence, both positive and negative, which included the results of operations for the current and preceding years. We determined that it was not possible to reasonably quantify future taxable income and determined that it is more likely than not that all of the deferred tax assets will not be realized. Accordingly, we maintained a full valuation allowance as of December 31, 2023 and 2022.

Under Internal Revenue Code Section 382, if a corporation undergoes an “ownership change,” the corporation’s ability to use its pre-change NOL carryforwards and other pre-change tax attributes to offset its post-change income may be limited. We have not completed a study to assess whether an “ownership change” has occurred or whether there have been multiple ownership changes since we became a “loss corporation” as defined in Section 382. Future changes in our stock ownership, which may be outside of our control, may trigger an “ownership change.” In addition, future equity offerings or acquisitions that have equity as a component of the purchase price could result in an “ownership change.” If an “ownership change” has occurred or does occur in the future, utilization of the NOL carryforwards or other tax attributes may be limited, which could potentially result in increased future tax liability to us.

Utilization of net operating loss, or NOL, and R&D credit carryforwards may be subject to a substantial annual limitation under Section 382 of the Internal Revenue Code of 1986 due to ownership change limitations that have occurred previously or that could occur in the future. These ownership changes may limit the amount of NOL and R&D credit carryforwards that can be utilized annually to offset future taxable income and tax, respectively. There also could be additional ownership changes in the future, which may result in additional limitations in the utilization of the carryforward NOLs and credits.

A full valuation allowance has been provided against our deferred tax assets and, if a future assessment requires an adjustment, an adjustment would be offset by an adjustment to the valuation allowance. Thus, there would be no impact to the consolidated balance sheets or statements of operations if an adjustment were required.

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480990/946-20-50-13

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
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-Paragraph 1
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-Name Accounting Standards Codification
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 14
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482685/740-10-50-14

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 21
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-URI https://asc.fasb.org//1943274/2147482685/740-10-50-21

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
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-Name Accounting Standards Codification
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-URI https://asc.fasb.org//1943274/2147482526/740-270-50-1

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
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-Paragraph 17
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482685/740-10-50-17

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
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-Section S99
-Paragraph 1
-Subparagraph (SAB TOPIC 6.I.5.Q1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479360/740-10-S99-1

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 11.C)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479360/740-10-S99-2

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482603/740-30-50-2

+ Details

Note 13 - Collaboration, Licensing and Research Funding Agreements

12 Months Ended

Dec. 31, 2023

Corporate Partnership, Licensing and Research Funding Agreements [Text Block]

Note 13 – Collaboration, Licensing and Research Funding Agreements

Collaboration Agreement

Battelle Memorial Institute

In October 2014, we entered into a Collaboration Agreement with Battelle, or, as amended, the Battelle Collaboration Agreement, for the development of our ADS for use in a potential Phase 3 program. We had previously worked with Battelle, which has expertise in developing and integrating aerosol devices using innovative and advanced technologies, in connection with development of our Phase 2 ADS used in the AEROSURF Phase 2b clinical trial. Under the Battelle Collaboration Agreement, we and Battelle shared the costs of development for a three-stage development plan that included planning, executing the project plan and testing and completing verification and documentation of a new Phase 3 ADS, putting us in a position to manufacture a new Phase 3 ADS for use in the remaining AEROSURF development activities, including a potential Phase 3 clinical program, and, if approved, initial commercial activities. We retained final decision-making authority over all matters related to the design, registration, manufacture, packaging, marketing, distribution and sale of the Phase 3 ADS. We and Battelle shared the costs of the project plan equally. Battelle agreed to bear the cost of any cost overruns associated with the project plan and we agreed to bear the cost of any increase in cost resulting from changes in the scope of the product requirements. We also agreed that, if Battelle successfully completed the project plan in a timely manner, we would pay Battelle royalties equal to a low single-digit percentage of the worldwide net sales and license royalties on sales of AEROSURF for the treatment of RDS in premature infants, up to an initial aggregate limit of $25.0 million, which under a payment restructuring agreement (discussed below), was increased to $35.0 million. The Battelle Collaboration Agreement will end at the time we fulfill our payment obligations to Battelle, unless sooner terminated by a party as provided therein.

Pursuant to the A&R License Agreement described below, Licensee has agreed to assume certain of our obligations under the Battelle Collaboration Agreement.

Licensing and Research Funding Agreements

Lee’s Pharmaceutical (HK) Ltd.

Term Sheet and Project Financing Agreement

On March 18, 2020, we entered into the Term Sheet with Lee’s (HK), pursuant to which Lee’s (HK) provided financing for the development of AEROSURF. In August 2020, we entered into a Project Financing Agreement with Lee’s (HK), or the PF Agreement, formalizing the terms of the Term Sheet, and under which we received payments totaling $2.8 million through October 2020. On November 12, 2020, Lee’s (HK) provided notice of termination of additional funding under the PF Agreement, and we and Lee’s (HK) revised our plans for the continued development of AEROSURF. Lee’s (HK) agreed to continue the development of AEROSURF in Asia at its own cost. Lee’s (HK) agreed to fund an additional $1.0 million to us in 2021 for certain transition and analytical services to be provided by us with respect to the development of AEROSURF, which will be considered “Project Expenses” under the terms of the PF Agreement. In 2021, we received payments totaling $1.0 million from Lee’s (HK) and no further amounts were due under the PF Agreement.

Since the 2018 acquisition of CVie Investments Limited and CVie Therapeutics, istaroxime has become our primary focus for investment and execution due to what we believe represents a greater potential value opportunity for us and our stockholders. Since completing our Phase 2 study of lucinactant (KL4 surfactant) for patients with severe COVID-19 associated ARDS and lung injury in January 2022, in order to preserve resources for the highest priority programs, we have begun to reduce costs not already being performed by our licensee, Lee’s (HK) and Zhaoke, under the terms of our Original License Agreement. These costs include certain reductions in headcount dedicated to KL4 surfactant and the decommissioning of both our analytical and technical support laboratory, which previously conducted release testing of APIs and supportive research for our lyophilized and aerosolized KL4 surfactant, and our medical device development laboratory, which was previously used to conduct development activities and testing for our ADS technologies. To support the future development of our KL4 surfactant platform in markets outside of Asia, including the U.S., we are pursuing one or more licensing transactions.

To repay the funds provided under the terms of the PF Agreement, until such time as we have repaid 125% of the amounts funded by Lee’s (HK) for the development of AEROSURF, we will pay to Lee’s (HK) 50% of all revenue amounts and payments received by us for any sale, divestiture, license or other development and/or commercialization of the KL4/AEROSURF patent portfolio, excluding (i) payments for bona fide research and development services; (ii) reimbursement of patent expenses and (iii) all amounts paid to us under the Original License Agreement, minus certain deductions and certain reductions for any payments made by us with respect to third party intellectual property not previously funded by Lee’s (HK).

As of December 31, 2023 and 2022, the liability balance related to the payments under the PF Agreement was $3.8 million and is recorded in other liabilities.

We have determined that the Term Sheet and the PF Agreement are within the scope of ASC 730-20, Research and Development Arrangements, or ASC 730-20. We concluded that there has not been a substantive and genuine transfer of risk related to the Term Sheet or the PF Agreement as there is a presumption that we are obligated to repay Lee’s (HK) based on the significant related party relationship that existed at the time the parties entered into the Term Sheet and the PF Agreement, including Lee’s (HK)’s ownership of outstanding shares of our common stock.

We have determined that the appropriate accounting treatment under ASC 730-20 is to record the proceeds received from Lee’s (HK) as cash and cash equivalents, as we have the ability to direct the usage of funds, and a long-term liability on our consolidated balance sheet when received. The liability will remain on the balance sheet until we repay such amounts as a result of any revenues and payments received by us for any sale, divestiture, license or other development and/or commercialization of the KL4/AEROSURF patent portfolio. We have also determined that the Term Sheet and the PF Agreement are not in their entirety a derivative under the scope of ASC 815, due to the scope exception under ASC 815-10-15-59, nor are there any embedded derivatives that require separate accounting.

A&R License Agreement

Previously, we were developing a KL4 surfactant platform, including AEROSURF (lucinactant for inhalation), to address a range of serious respiratory conditions in children and adults. In order to focus our resources on the development of our istaroxime pipeline, we suspended all internal AEROSURF clinical activities in November 2020, and, in January 2022 we began to reduce all other costs related to the KL4 surfactant platform that were not already being performed by our licensee, Lee’s (HK) and Zhaoke, under the terms of the Original License Agreement.

On August 17, 2022, we entered into an Amended and Restated License, Development and Commercialization Agreement, or the A&R License Agreement, with Lee’s (HK) and Zhaoke effective as of August 9, 2022. We refer to Zhaoke and Lee’s (HK) together as the “Licensee.” The A&R License Agreement amends, restates, and supersedes the Original License Agreement.

Under the A&R License Agreement, we granted to Licensee an exclusive license, with a right to sublicense, to develop, register, make, use, sell, offer for sale, import, distribute, and otherwise commercialize our KL4 surfactant products, including SURFAXIN®, the lyophilized dosage form of SURFAXIN, and aerosolized KL4 surfactant, in each case for the prevention, mitigation and/or treatment of any respiratory disease, disorder, or condition in humans worldwide, except for Andorra, Greece, and Italy (including the Republic of San Marino and Vatican City), Portugal, and Spain, or the Licensed Territory, which countries are currently exclusively licensed to Laboratorios Del Dr. Esteve, S.A., or Esteve. If and when the exclusive license granted to Esteve terminates as to any country, such country automatically becomes part of the Licensed Territory of Licensee.

Under the Original License Agreement, Lee’s (HK) previously made an upfront payment to us of $1.0 million. Pursuant to the terms of the A&R License Agreement, we may also receive up to $78.9 million in potential clinical, regulatory and commercial milestone payments. We are also entitled to receive a low double-digit percentage of Licensee’s non-royalty sublicense income. We are also eligible to receive tiered royalties based on a percentage of Net Sales (as defined in the A&R License Agreement) that ranges from low single digit to low teen percentages, depending on the product. Royalties are payable on a product-by-product and country-by-country basis until the latest of (i) the expiration of the last valid patent claim covering the product in the country of sale, (ii) the expiration or revocation of any applicable regulatory exclusivity in the country of sale, and (iii) ten years after the first commercial sale of the product in the country of sale. Thereafter, in consideration of licensed rights other than patent rights, royalties shall continue for the commercial life of each product but at substantially reduced rates. In addition, the royalty rates are subject to reduction by as much as 50% in a given country based on generic competition in such country.

The A&R License Agreement is considered to be a contract modification in accordance with ASC Topic 606. No additional performance obligations were identified in the contract modification, and no future material performance obligations are due.

All revenue related to the $1.0 million upfront payment under the Original License Agreement was appropriately recognized as of the second quarter of 2019. Regulatory and commercialization milestones under the A&R License Agreement were excluded from the transaction price, as all milestone amounts were fully constrained under the guidance. Consideration related to sales-based milestones and royalties under the A&R License Agreement will be recognized when the related sales occur, provided that the reported sales are reliably measurable and that we have no remaining performance obligations, as such sales were determined to relate predominantly to the license granted to Licensee and therefore have also been excluded from the transaction price. We will re-evaluate the transaction price in each reporting period and as uncertain events are resolved or other changes in circumstances occur.

Under the A&R License Agreement, Licensee will be solely and exclusively responsible for all costs and activities related to the development, manufacturing, regulatory approval and commercialization of licensed products in the Licensed Territory including all royalties payable in respect of third-party intellectual property rights sublicensed by us to Licensee and all intellectual property prosecution, maintenance and defense activities and costs. Licensee may sublicense certain activities under the A&R License Agreement to an affiliate of Licensee but may not grant sublicenses to unaffiliated third parties without our prior consent and, if the proposed sublicense will cover the U.S., without first complying with rights of first offer and rights to match granted to us under the A&R License Agreement. A sublicensee and a subcontractor may not be a competitor identified by us. Sublicenses under the A&R License Agreement do not include the right to further sublicense.

The term of the A&R License Agreement will continue on a country-by-country basis for the commercial life of the products. Either party may terminate the A&R License Agreement in the event of bankruptcy or a material breach of the A&R License Agreement by the other party that remains uncured for a period of sixty (60) days (or within 30 days after delivery of a Default Notice (as defined in the A&R License Agreement) if such material breach is solely based on the breaching party’s failure to pay amount due under the A&R License Agreement). At any time after the second anniversary of the A&R License Agreement, Licensee may terminate the A&R License Agreement in its entirety or on a product-by-product basis. In addition, either party may terminate the A&R License Agreement with respect to any individual product in a country if a regulatory authority in such country terminates, suspends or discontinues development of such product and such termination, suspension or discontinuance persists for a period in excess of eighteen (18) months. Upon termination of the A&R License Agreement in its entirety or with respect to a particular product or country, generally all related rights and licenses granted to Licensee will terminate, all rights under our technology will revert to us, and Licensee will cease all use of our technology, in each case in relation to the terminated product(s) and country(ies), as applicable.

License, Development and Commercialization Agreement with Lee’s Pharmaceutical (HK) Ltd.

On January 12, 2024, we entered into a License, Development and Commercialization Agreement with Lee’s (HK) effective as of January 7, 2024 under which we granted an exclusive license, with a right to sublicense, to develop, register, make, use, sell, offer for sale, import, distribute and otherwise commercialize products that incorporate istaroxime for intravenous administration, rostafuroxin for oral administration, and our proprietary dual-mechanism SERCA2a activators for intravenous or oral administration, in each case for the prevention, mitigation and/or treatment of any disease, disorder or condition in humans including acute decompensated heart failure, cardiogenic shock, and chronic use following discharge of an individual hospitalized for acute decompensated heart failure in the Greater China region (See the section titled, “Note 18 – Subsequent Events”).

Philip Morris USA Inc. and Philip Morris Products S.A.

In 2008, we entered into the U.S. License Agreement with PMUSA and, as PMUSA had assigned its ex-U.S. rights to PMPSA effective on the same date and on substantially the same terms and conditions, we entered into a license agreement with PMPSA with respect to rights outside of the U.S., which we refer to, together with the U.S. License Agreement, as the PM License Agreements. Under the PM License Agreements, we hold exclusive worldwide licenses to the ADS technology for use with pulmonary surfactants (alone or in combination with any other pharmaceutical compound(s)) for all respiratory diseases and conditions (the foregoing uses in each territory, or the Exclusive Field), and an exclusive license in the U.S. for use with certain non-surfactant drugs to treat specified respiratory indications in humans in designated hospital settings. The PM License Agreements provide for payment of royalties at a rate equal to a low single-digit percent of sales of products sold in the Exclusive Field (as defined in the PM License Agreements) in the territories, including sales of aerosol devices that are not based on the ADS technology (unless we exercise our right to terminate the license with respect to a specific indication). While there is no legal obligation under the agreements to make minimum royalty payments, in the event we do not make quarterly minimum royalty payments, PMUSA and PMPSA can terminate the agreements. In making such payments, we are entitled to a reduction of future royalties in an amount equal to the excess of any minimum royalty paid over royalties actually earned in prior periods.

Pursuant to the A&R License Agreement described above, Licensee has agreed to assume certain of our obligations under the PM License Agreements.

On January 16, 2024, we entered into Amendment No. 1 to the U.S. License Agreement with PMUSA and also entered into Amendment No. 1 to the License Agreement with PMPSA in which the parties extinguished and released their respective rights, obligations and claims in respect of quarterly payments in effect immediately prior to January 17, 2024 (See the section titled, “Note 9 – Other Current Liabilities”).

Johnson & Johnson and Ortho Pharmaceutical Corporation

We, Johnson & Johnson, or J&J, and its wholly owned subsidiary, Ortho Pharmaceutical Corporation, are parties to a license agreement granting to us an exclusive worldwide license to the J&J KL4 surfactant technology. Under the license agreement, we are obligated to pay fees of up to $2.5 million in the aggregate upon our achievement of certain milestones, primarily upon receipt of marketing regulatory approvals for certain designated products. We have paid $1.0 million to date for milestones that have been achieved. In addition, the license agreement requires that we make royalty payments at different rates, depending upon type of revenue and country, in amounts in the range of a high single-digit percent of net sales (as defined in the license agreement) of licensed products sold by us or sublicensees, or, if greater, a percentage of royalty income from sublicensees in the low double digits.

Pursuant to the A&R License Agreement described above, Licensee has agreed to assume certain of our obligations under our license agreement with J&J.

Laboratorios del Dr. Esteve, S.A.

We have a strategic alliance with Esteve for the development, marketing and sales of a broad portfolio of potential KL4 surfactant products in Andorra, Greece, and Italy (including the Republic of San Marino and Vatican City) Portugal, and Spain, or, collectively, the Territory. Antonio Esteve, Ph.D., a principal of Esteve, served as a member of our Board of Directors from May 2002 until January 2013. Under the alliance, Esteve will pay us a transfer price on sales of our KL4 surfactant products. We are responsible for the manufacture and supply of all of the covered products and Esteve will be responsible for all sales and marketing in the Territory. Esteve is obligated to make stipulated cash payments to us upon our achievement of certain milestones, primarily upon receipt of marketing regulatory approvals for the covered products. In addition, Esteve has agreed to contribute to Phase 3 clinical trials for the covered products by conducting and funding development performed in the Territory. As part of a 2004 restructuring, Esteve returned certain rights to us in certain territories, or the Former Esteve Territories, and we agreed to pay Esteve 10% of any cash up front and milestone fees (up to a maximum aggregate of $20.0 million) that we receive in connection with any strategic collaborations for the development and/or commercialization of certain of our KL4 surfactant products in the Former Esteve Territories.

Universita degli Studi di Milano-Bicocca

Effective April 13, 2015, CVie Therapeutics, entered into an Agreement for Scientific Collaboration with the Universita degli Studi di Milano-Bicocca, or Bicocca, in Milan, Italy, focused on defining the role of SERCA2a and phospholamban, or PLN, in modulating cardiac contraction, and discovering new small molecules to modulate SERCA2a activity or new drugs for treating chronic and acute human heart failure. The term of the collaboration agreement would have expired after three years but was extended for approximately an additional year, with the option for further renewal.

Under the collaboration agreement, intellectual property resulting from the collaboration, including patents and know-how, will be jointly owned by the parties. For the development of any new SERCA2a compounds and diagnostic products suitable for further clinical development, we have the option to purchase Bicocca’s interest for up to 12 months after the filing of a patent application. If the option is not exercised, then the parties shall remain joint owners and each can use the intellectual property with consent of the other on terms to be defined. If we exercise an option, we have agreed to pay Bicocca (corresponding to stage of development): (i) € 0.1 million upon completion and the proof of concept of biological efficacy for new compounds modulating the SERCA2a activity caused by PLN mutations; and (ii) € 1.5 million upon obtaining marketing authorization in the U.S., EU, or China of new compounds with the corresponding companion diagnostic assay. We have also agreed to pay royalties for any purchased intellectual property arising out of the collaboration in the range of a low- to mid-single digit percent of net sales for any products sold in any country for a period of ten years from the date of the first commercial sale.

On March 19, 2021, we entered into an Agreement for Scientific Collaboration, or the New SERCA2a Agreement, with Bicocca, which extends our collaboration. The New SERCA2a Agreement amends and restates the recently expired terms of the prior collaboration agreement. Under the New SERCA2a Agreement, we will provide Bicocca with approximately € 0.2 million for research activities and to cover laboratory space and operation costs. Results obtained from the collaboration will be jointly owned by the parties. However, Bicocca will assign to us its interest in patent applications and patents covering any new SERCA2a compounds and diagnostic products suitable for further clinical development. We have agreed to pay Bicocca (corresponding to stage of development): (i) € 25,000 for execution of an assignment to us of Bicocca’s interest in the patent at issue, (ii) € 75,000 for new SERCA2a compounds developed up to Phase 1 studies in humans upon the completion and availability of the proof of concept of biological efficacy of new compounds on modulating the SERCA2a activity in cell-free systems, or its functional counterpart in isolated cells and (iii) € 1.5 million upon obtaining marketing authorization in the U.S., EU, or China of new compounds with the corresponding companion diagnostic assay. We have also agreed to pay royalties on products generated from the collaboration in the range of a fraction of a single digit to a low single digit percent of net sales for any products sold in any country for a period of ten years from the date of the first commercial sale or until the expiry of patent(s) covering the products. In connection with our research activities, Bicocca agreed to provide us exclusive use of a research laboratory for the collaboration, and nonexclusive access to a physiology laboratory within the university. Bicocca served as our primary location in Milan, Italy.

Our agreement with Universita Degli Studi di Milano-Bicocca, the institution that has performed many preclinical studies with istaroxime and our preclinical families of compounds, expired on July 31, 2022. If additional preclinical work is required for any reason, we will need to re-engage with Bicocca or find another vendor to provide those services.

Note 17 - Leases (Details Textual)	1 Months Ended
Note 17 - Leases (Details Textual)	Jan. 31, 2023
Amendment to Extend Warrington, Pennsylvania Lease [Member]
Lessee, Operating Lease, Extended Term (Year)	5 years

Note 5 - Fair Value Measurements

12 Months Ended

Dec. 31, 2023

Fair Value Disclosures [Text Block]

Note 5 – Fair Value Measurements

Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date.

Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. The fair value hierarchy is based on three levels of inputs, of which the first two are considered observable and the last unobservable, as follows:

	●	Level 1 - Quoted prices in active markets for identical assets and liabilities.
	●	Level 2 - Inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices for similar assets or liabilities, quoted prices in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities.
	●	Level 3 - Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities.

Fair Value on a Recurring Basis

The tables below categorize assets measured at fair value on a recurring basis as of December 31, 2023 and 2022:

	Fair Value		Fair value measurement using
	December 31,
(in thousands)	2023		Level 1		Level 2		Level 3

Cash equivalents:
Money market funds	$	3,532	$	3,532	$	-	$	-
Total Assets	$	3,532	$	3,532	$	-	$	-

	Fair Value		Fair value measurement using
	December 31,
(in thousands)	2022		Level 1		Level 2		Level 3

Cash equivalents:
Money market funds	$	4,212	$	4,212	$	-	$	-
Total Assets	$	4,212	$	4,212	$	-	$	-

Fair Value on a Non-Recurring Basis

The table below categorizes assets measured at fair value on a non-recurring basis for the periods presented:

Fair Value

Fair value measurement using

December 31,

(in thousands)

2023

Level 1

Level 2

Level 3

Goodwill

	Fair Value		Fair value measurement using
	December 31,
(in thousands)	2022		Level 1		Level 2		Level 3

Intangible assets:
Rostafuroxin drug candidate	$	2,910	$	-	$	-	$	2,910

Goodwill	$	3,058	$	-	$	-	$	3,058

Certain of our assets were measured at fair value on a non-recurring basis during the years ended December 31, 2023 and 2022. The IPR&D intangible asset related to our rostafuroxin drug candidate was recorded at its estimated fair value as a result of the impairment tests performed during 2022. Our goodwill was also recorded at its estimated fair value as a result of the impairment tests performed in 2023 and 2022, which resulted in the goodwill being written down to zero as of June 30, 2023 (See the section titled, “Note 4 – Accounting Policies – Intangible Assets and Goodwill”).

Significant factors considered in estimating the fair value of the IPR&D intangible asset related to our rostafuroxin drug candidate include the risks inherent in the development process, including the likelihood of achieving commercial success and the cost and related time to complete the remaining development. Future cash flows for the IPR&D intangible asset were estimated based on forecasted revenue and costs, taking into account the expected product life cycle, market penetration, and growth rates. Other significant estimates and assumptions inherent in this approach include (i) the amount and timing of the projected net cash flows associated with the IPR&D intangible asset; (ii) the discount rate, which seeks to reflect the various risks inherent in the projected cash flows; and (iii) the tax rate, which considers geographic diversity of the projected cash flows. Quantitative information about the significant unobservable inputs used in the fair value measurement of the IPR&D intangible asset included a discount rate of 20.0% and a tax rate of 30.0% for 2022. While we use the best available information to prepare our cash flows and discount rate assumptions, actual future cash flows could differ significantly based on the commercial success of the related drug candidate and market conditions which could result in future impairment charges related to the indefinite-lived intangible asset balance.

In order to perform the goodwill impairment test, we compare the estimated fair value of our reporting unit to its carrying value. Significant factors considered in estimating the fair value of our reporting unit include the use of the quoted market price and related market capitalization of our common stock, adjusted for an estimated control premium based on transactions completed by comparable companies. Quantitative information about the significant unobservable inputs used in the fair value measurement of the reporting unit included an estimated control premium of 50% for both periods.

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

Note 5 - Fair Value Measurements - Assets Measured at Fair Value on a Non-recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Indefinite-Lived Intangible Assets (Excluding Goodwill), Fair Value Disclosure		$ 2,900
Fair Value, Nonrecurring [Member]
Goodwill	$ 0	3,058
Fair Value, Nonrecurring [Member] \| Rostafuroxin Drug Candidate [Member]
Indefinite-Lived Intangible Assets (Excluding Goodwill), Fair Value Disclosure		2,910
Fair Value, Nonrecurring [Member] \| Fair Value, Inputs, Level 1 [Member]
Goodwill	0	0
Fair Value, Nonrecurring [Member] \| Fair Value, Inputs, Level 1 [Member] \| Rostafuroxin Drug Candidate [Member]
Indefinite-Lived Intangible Assets (Excluding Goodwill), Fair Value Disclosure		0
Fair Value, Nonrecurring [Member] \| Fair Value, Inputs, Level 2 [Member]
Goodwill	0	0
Fair Value, Nonrecurring [Member] \| Fair Value, Inputs, Level 2 [Member] \| Rostafuroxin Drug Candidate [Member]
Indefinite-Lived Intangible Assets (Excluding Goodwill), Fair Value Disclosure		0
Fair Value, Nonrecurring [Member] \| Fair Value, Inputs, Level 3 [Member]
Goodwill	$ 0	3,058
Fair Value, Nonrecurring [Member] \| Fair Value, Inputs, Level 3 [Member] \| Rostafuroxin Drug Candidate [Member]
Indefinite-Lived Intangible Assets (Excluding Goodwill), Fair Value Disclosure		$ 2,910

Note 12 - Stock Options and Stock-based Employee Compensation (Tables)

12 Months Ended

Dec. 31, 2023

Schedule of Share Based Compensation Arrangement by Stock Options and Restricted Stock Units Outstanding and Available for Future Issuance [Table Text Block]

	December 31,
(in thousands)	2023		2022

Stock Options and RSUs Outstanding
2020 Plan		393		50
2011 Plan		29		30
Non-Plan		2		9
Total Outstanding		424		89

Available for Future Grants under the 2020 Plan		339		12

Disclosure of Share-Based Compensation Arrangements by Share-Based Payment Award [Table Text Block]

(in thousands, except for weighted-average data)
Stock Options	Shares			Weighted-Average Exercise Price		Weighted-Average Remaining Contractual Term (In Years)

Outstanding at January 1, 2023		78		$	381.00
Granted		213			1.21
Forfeited or expired		(14	)		259.02
Outstanding at December 31, 2023		277		$	92.41		8.8

Vested and exercisable at December 31, 2023		56		$	432.45		5.9

Vested and expected to vest at December 31, 2023		254		$	94.53		8.8

Share-Based Payment Arrangement, Restricted Stock Unit, Activity [Table Text Block]

(in thousands, except for weighted-average data)
Restricted Stock Units	Shares			Weighted- Average Grant Date Fair Value

Outstanding at January 1, 2023		11		$	49.50
Awarded		142			1.21
Vested		(3	)		48.55
Cancelled		(3	)		49.57
Outstanding at December 31, 2023		147		$	2.94

Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block]

	Year Ended December 31,
(in thousands)	2023		2022

Research and development	$	383	$	807
General and administrative		895		2,279
Total	$	1,278	$	3,086

Schedule of Share-Based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

	Year Ended December 31,
	2023			2022

Weighted average expected volatility		112	%		106	%
Weighted average expected term		6.0			6.9
Weighted average risk-free interest rate		4.33	%		1.70	%
Expected dividends		-			-

Insider Trading Arrangements	12 Months Ended
Insider Trading Arrangements	Dec. 31, 2023
Insider Trading Arr Line Items
Material Terms of Trading Arrangement [Text Block]	ITEM 9B. OTHER INFORMATION. None.
Rule 10b5-1 Arrangement Adopted [Flag]	false
Non-Rule 10b5-1 Arrangement Adopted [Flag]	false
Rule 10b5-1 Arrangement Terminated [Flag]	false
Non-Rule 10b5-1 Arrangement Terminated [Flag]	false

Note 3 - Going Concern and Management's Plans

12 Months Ended

Dec. 31, 2023

Liquidity Disclosures [Text Block]

Note 3 – Going Concern and Management’s Plans

We are subject to risks common to companies in the biotechnology industry, including but not limited to, the need for additional capital, risks of failure of preclinical and clinical studies, the need to obtain marketing approval and reimbursement for any drug product candidate that we may identify and develop, the need to successfully commercialize and gain market acceptance of our product candidates, dependence on key personnel, protection of proprietary technology, compliance with government regulations, development of technological innovations by competitors, and risks associated with our international operations in Taiwan and activities abroad, including but not limited to having foreign suppliers, manufacturers, and clinical sites in support of our development activities.

We have incurred net losses since inception. Our net loss was $20.3 million and $39.2 million, respectively, for the years ended December 31, 2023 and 2022. Included in our net loss for the year ended December 31, 2023 is a non-cash loss on impairment of goodwill of $3.1 million. Included in our net loss for the year ended December 31, 2022 are a non-cash loss on impairment of goodwill of $12.6 million, a non-cash loss on impairment of intangible assets related to rostafuroxin of $6.8 million and a related $1.4 million deferred income tax benefit (See the section titled, “Note 4 – Accounting Policies”). We expect to continue to incur operating losses for at least the next several years. As of December 31, 2023, we had an accumulated deficit of $844.8 million. Our future success is dependent on our ability to fund and develop our product candidates, and ultimately upon our ability to attain profitable operations. We have devoted substantially all of our financial resources and efforts to research and development and general and administrative expense to support such research and development. Net losses and negative cash flows have had, and will continue to have, an adverse effect on our stockholders’ equity and working capital, and accordingly, our ability to execute our future operating plans.

On November 9, 2023, we entered into an At-The-Market Offering Agreement with Ladenburg Thalmann & Co. Inc., or Ladenburg, pursuant to which we may offer and sell, from time to time at our sole discretion, shares of our common stock through Ladenburg as agent and/or principal (subject to the limitations of General Instruction I.B.6 of Form S-3) through an at-the-market program, or the 2023 ATM Program (See the section titled, “Note 11 – Mezzanine Equity and Stockholders’ Equity”).

The shares of common stock we may issue or sell under the 2023 ATM Program are registered under our Registration Statement on Form S-3 (File No. 333-261878), which was declared effective by the SEC on January 3, 2022. We are currently subject to the limitations contained in General Instruction I.B.6 of Form S-3. As a result, we are limited to selling no more than one-third of the aggregate market value of the equity held by non-affiliates, or the public float, during any 12-month period, and, as of April 16, 2024, we had sold substantially all that we are permitted to sell under the Form S-3 pursuant to General Instruction I.B.6. If our public float increases, we will have additional availability under such limitations, and if our public float increases to $75 million or more, we will no longer be subject to such limitations. There can be no assurance that our public float will increase or that we will no longer be subject to such limitations.

As of December 31, 2023, we had cash and cash equivalents of $4.3 million and current liabilities of $4.0 million. On April 2, 2024, we entered into a Securities Purchase Agreement, or the Purchase Agreement, with the buyers named therein, or the Buyers. Pursuant to the Purchase Agreement, we agreed to sell senior convertible notes, or the Notes, for $1.5 million of gross proceeds. As a result, we believe that we have sufficient resources available to fund our business operations through April 2024. We do not have sufficient cash and cash equivalents as of the date of this Annual Report on Form 10-K to support our operations for at least the 12 months following the date that the financial statements are issued. These conditions raise substantial doubt about our ability to continue as a going concern.

To alleviate the conditions that raise substantial doubt about our ability to continue as a going concern, management plans to secure additional capital, potentially through a combination of public or private securities offerings, convertible debt financings, and/or strategic transactions, including potential licensing arrangements, alliances, and drug product collaborations focused on specified geographic markets; however, none of these alternatives are committed at this time. There can be no assurance that we will be successful in obtaining sufficient funding on terms acceptable to us to fund continuing operations, if at all, or identify and enter into any strategic transactions that will provide the capital that we will require. The failure to obtain sufficient additional capital on acceptable terms when needed would have a material adverse effect on our business, results of operations, and financial condition. Accordingly, management has concluded that substantial doubt exists with respect to our ability to continue as a going concern for at least 12 months after the issuance of the accompanying financial statements.

The accompanying financial statements have been prepared on a going concern basis, which contemplates the realization of assets and satisfaction of liabilities in the normal course of business, and do not include any adjustments relating to recoverability and classification of recorded asset amounts or the amounts and classification of liabilities that might be necessary should we be unable to continue as a going concern.

Consolidated Statements of Changes in Mezzanine Equity and Stockholders' Equity (Parentheticals) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
ATM Program [Member]
Adjustments to Additional Paid in Capital, Stock Issued, Issuance Costs	$ 23	$ 131
Adjustments to Additional Paid in Capital, Stock Issued, Issuance Costs	1,630
Adjustments to Additional Paid in Capital, Stock Issued, Issuance Costs, Exercise of Warrants Cost	$ 276

Note 18 - Subsequent Events

12 Months Ended

Dec. 31, 2023

Subsequent Events [Text Block]

Note 18 – Subsequent Events

License Agreement with Lee’s Pharmaceutical (HK) Ltd.

On January 12, 2024, we entered into a License, Development and Commercialization Agreement with Lee’s (HK) effective as of January 7, 2024, or the Lee’s (HK) License Agreement. Under the Lee’s (HK) License Agreement, we granted an exclusive license, with a right to sublicense, to develop, register, make, use, sell, offer for sale, import, distribute and otherwise commercialize products that incorporate istaroxime for intravenous administration, rostafuroxin for oral administration, and our proprietary dual-mechanism SERCA2a activators for intravenous or oral administration (collectively, the Products and each, a Product), in each case for the prevention, mitigation and/or treatment of any disease, disorder or condition in humans including acute decompensated heart failure, cardiogenic shock, and chronic use following discharge of an individual hospitalized for acute decompensated heart failure, or Field, in the People’s Republic of China, Hong Kong, Macau, Taiwan, Singapore, South Korea, Thailand, Vietnam, Brunei, Myanmar, Cambodia, East Timor, Indonesia, Laos, Malaysia, and the Philippines, or the New Licensed Territory.

Under the Lee’s (HK) License Agreement, we may receive up to $3.1 million in potential upfront pre-development, development, clinical, and regulatory milestone payments and up to $135.25 million in sales milestone payments. We are also entitled to receive a low double-digit percentage of Lee’s (HK) non-royalty sublicense income.

We are eligible to receive tiered royalties based on a percentage of Net Sales (as defined in the Lee’s (HK) License Agreement) that ranges from low single-digit to low double-digit percentages, depending on the Product. Royalties are payable on a product-by-product and country-by-country basis until the latest of (i) the expiration of the last valid patent claim covering the Product in the country of sale, (ii) the expiration or revocation of any applicable regulatory exclusivity in the country of sale, and (iii) ten years after the first commercial sale of the Product in the country of sale. Thereafter, in consideration of licensed rights other than patent rights, royalties shall continue for the commercial life of each Product but at substantially reduced rates. In addition, the royalty rates are subject to reduction by as much as 50% in a given country based on generic competition in such country.

Under the Lee’s (HK) License Agreement, Lee’s (HK) will be solely and exclusively responsible for all costs and activities related to the development, manufacturing, regulatory approval and commercialization of Products in the New Licensed Territory, with the exception of certain costs in connection with filing fees payable to regulatory authorities in the New Licensed Territory relative to a Product for which we hold the applicable marketing authorization. Lee’s (HK) may sublicense its rights to its affiliates and may grant sublicenses to third-party subcontractors to perform certain activities under the Lee’s (HK) License Agreement on behalf of Lee’s (HK) or its affiliates but may not otherwise grant sublicenses to unaffiliated third parties without our prior consent. A sublicensee and a subcontractor may not be a competitor identified by us. Sublicenses granted under the Lee’s (HK) License Agreement may not include the right to further sublicense. The Lee’s (HK) License Agreement establishes a joint steering committee and a joint development committee to oversee the regional development (with us retaining final decision rights over clinical protocols) and a joint commercialization committee.

During the term of the Lee’s (HK) License Agreement, we receive an exclusive (even as to Lee’s (HK)), sublicensable license under any Lee’s (HK) and its affiliate’s intellectual property that covers a Product (including its manufacture and use) and any improvements to the licensed technology developed solely by or on behalf of Lee’s (HK) or jointly with us, to (i) develop Product in the Field to obtain or maintain regulatory approval outside of the New Licensed Territory, and (ii) use, sell, offer for sale, import, export, make, have made, distribute, warehouse, market, promote, apply for and submit applications for drug approval and reimbursement approval and otherwise commercialize Product in the Field outside of the New Licensed Territory. After the term of the Lee’s (HK) License Agreement, or in the event that we wish to obtain an exclusive license under certain patent rights during or after the term, we have the option to negotiate an exclusive royalty-bearing license under any such intellectual property, provided that such royalties shall not exceed specified low single-digit caps.

Under the Lee’s (HK) License Agreement, each party is responsible for prosecution and maintenance of its respective solely-owned patents, and the parties shall decide on a case-by-case basis the appropriate allocation of costs and control concerning matters regarding the prosecution, maintenance, defense and infringement of any jointly-owned patents. The Lee’s (HK) License Agreement provides for cooperation between the parties with respect to enforcement of patent rights. As between the parties, we have the first right to enforce patent rights against third parties at our own expense. If we decline to enforce such rights, Lee’s (HK) has the right to enforce such rights at its own expense. In the event that a third party claims that a Product used or sold by Lee’s (HK) (or its affiliate or sublicensee) is infringing on a patent in the New Licensed Territory, Lee’s (HK) is responsible for defending against such third party claim at its cost and expense, with the exception of certain counterclaims that we may bring.

The term of the Lee’s (HK) License Agreement will continue on a country-by-country basis for the commercial life of the Products. Either party may terminate the Lee’s (HK) License Agreement in the event of bankruptcy or a material breach of the Lee’s (HK) License Agreement by the other party that remains uncured for a period of sixty days (or within 30 days after delivery of a Default Notice (as defined in the Lee’s (HK) License Agreement) if such material breach is solely based on the breaching party’s failure to pay amount due under the Lee’s (HK) License Agreement). In addition, either party may terminate the Lee’s (HK) License Agreement with respect to any individual Product in a country if a regulatory authority in such country terminates, suspends or discontinues development of such Product and such termination, suspension or discontinuance persists for a period in excess of 18 months. Upon termination of the Lee’s (HK) License Agreement in its entirety or with respect to a particular Product or country, generally all related rights and licenses granted to Lee’s (HK) will terminate, all rights under our technology will revert to us, and Lee’s (HK) will cease all use of our technology, in each case in relation to the terminated Product(s) and country(ies), as applicable.

Exchange and Termination Agreement with Deerfield Management Company, L.P.

On January 24, 2024, we and affiliates of Deerfield entered into an Exchange and Termination Agreement, or the Exchange and Termination Agreement. Pursuant to the Milestone Agreement, among other things, Deerfield had the right to receive the Milestone Payments, which, if achieved, could potentially total up to $15.0 million.

Pursuant to the Exchange and Termination Agreement, Deerfield agreed to terminate its rights to receive the Milestone Payments and all related rights and obligations in respect of such Milestone Payments in exchange for (i) cash in the aggregate amount of $200,000, $100,000 of which was paid on January 24, 2024 and $100,000 of which will be paid no later than the earlier to occur of (a) January 24, 2025 and (b) us receiving a specified amount of gross proceeds from debt or equity financings occurring on or after January 24, 2024, and (ii) an aggregate of 608,272 shares of our common stock, par value $0.001 per share. The shares of the common stock were issued to Deerfield in a transaction exempt from registration pursuant Section 4(a)(2) of the Securities Act of 1933.

Contemporaneously with the execution of the Exchange and Termination Agreement, we and Deerfield entered into a Registration Rights Agreement pursuant to which we have agreed to, among other matters, register for resale with the SEC the shares of the common stock issued to Deerfield pursuant to the Exchange and Termination Agreement.

Asset Purchase Agreement with Varian Biopharmaceuticals

On April 2, 2024, we entered into the Asset Purchase Agreement with Varian. Pursuant to the Asset Purchase Agreement, we purchased all of the assets of Varian’s business associated with the Licence Agreement, including the Licence Agreement, all rights in molecules and compounds subject to the Licence Agreement, know-how and inventory of drug substance, or the Transferred Assets. We also assumed all liabilities arising on or after April 2, 2024, relating to the research, development, manufacturing, registration, commercialization, use, handling, supply, storage, import, export or other disposition or exploitation of any and all products associated with the Transferred Assets.

In consideration of the purchase of the Transferred Assets, (i) on April 2, 2024, we issued a total of 5,500 shares of our Series B Convertible Preferred Stock, par value $0.001 per share, or the Series B Preferred Stock, to certain creditors of Varian and (ii) agreed to pay up to $2.3 million in milestone payments upon the achievement of certain regulatory and clinical development milestones with our option to pay such milestone payments either in cash or our common stock.

The Asset Purchase Agreement contains customary representations and warranties, covenants, closing conditions and indemnification provisions for a transaction of this nature, including, without limitation, confidentiality and non-compete undertakings by Varian.

Series B Preferred Stock

The terms of the Series B Preferred Stock are as set forth in the Series B Certificate of Designation of Series B Preferred Stock, as filed with the Delaware Secretary of State and effective on April 3, 2024. The Series B Certificate of Designation authorizes a total of 5,500 shares of Series B Preferred Stock, or the Series B Preferred Stock, with an initial conversion price of $0.3603, or the Preferred Conversion Price, which is subject to adjustment as provided in the Series B Certificate of Designation to no lower than $0.0721. The Series B Preferred Stock has a stated value of $1,000 per share, or the Stated Value, which equal to an aggregate Stated Value of $5,500,000 as of April 2, 2024. Each share of Series B Preferred Stock is initially convertible into 15,265 shares of our common stock, subject to adjustment as provided in the Series B Certificate of Designation. No fractional shares will be issued upon conversion; rather any fractional share will be rounded up to the nearest whole share.

From and after April 2, 2024, each holder of a share of Series B Preferred Stock is entitled to receive dividends, or Dividends, which are computed on the basis of a 360-day year and twelve 30-day months and will increase the Stated Value of the Series B Preferred Stock on each dividend date (as defined in the Series B Certificate of Designation).

Dividends on the Series B Preferred Stock will accrue at 10.0% per annum, or the Dividend Rate, and be payable by way of inclusion of the Dividends in the Conversion Amount (as defined in the Series B Certificate of Designation) on each Conversion Date (as defined in the Series B Certificate of Designation) in accordance with the Series B Certificate of Designation or upon any redemption in accordance with the Series B Certificate of Designation or upon any required payment upon any Bankruptcy Triggering Event (as defined in the Series B Certificate of Designation). From and after the occurrence and during the continuance of any Triggering Event (as defined in the Series B Certificate of Designation), the Dividend Rate will automatically be increased to 18.0% per annum.

The Preferred Conversion Price is subject to adjustment upon the occurrence of specified events and subject to price-based adjustment in the event of any stock split, stock dividend, stock combination, recapitalization or other similar transaction involving our common stock at a price below the then-applicable Preferred Conversion Price, as described in further detail in the Series B Certificate of Designation.

Securities Purchase Agreement and Convertible Notes

On April 2, 2024, we entered into the Purchase Agreement with the Buyers. Pursuant to the Purchase Agreement, we agreed to sell the Notes for $1.5 million of gross proceeds. The Notes have an initial conversion price of $0.3603, which is subject to adjustment upon the occurrence of specified events to no lower than $0.0721, subject to any stock split, stock dividend, stock combination, recapitalization or other similar transaction involving our common stock.

The Notes will be senior obligations of the Company. The Notes will accrue interest at a rate of 10.0% per annum, payable in arrears on the first calendar day of each calendar month, beginning on May 2, 2024, unless an event of default has occurred, upon which interest will accrue at 18.0% per annum. The Notes mature on January 2, 2025 unless earlier converted or redeemed (upon the satisfaction of certain conditions).

We may, subject to certain conditions, redeem all, but not less than all, of the amount then remaining under the Notes in cash at a premium of 20% of the greater of (i) the amount then outstanding under the Notes, and (ii) the equity value of our common stock underlying the Notes, which is calculated using the greatest closing sale price of our common stock on any trading day during the period commencing on the date of notice of such redemption and ending on the date we make the entire payment required pursuant to the Purchase Agreement. The Notes can also be redeemed by us under various other circumstances, such as a change of control, events of default, or at the option of the Buyer under limited circumstances, with any such redemption subject to the terms and conditions as set forth in the Notes.

The Notes contain certain conversion limitations, providing that no conversion may be made if, after giving effect to the conversion, the holder, together with any of its affiliates, would own in excess of 4.99% of our outstanding shares of common stock.

The Notes contain certain customary affirmative and negative covenants regarding the incurrence of indebtedness, the existence of liens, the repayment of indebtedness, the payment of cash in respect of dividends, distributions or redemptions and the transfer of assets, among other matters. The Notes also contain certain customary events of default, including, among other things, the failure to file and maintain an effective registration statement covering the certain registrable securities, subject to certain exceptions.

We agreed to seek stockholder approval for the issuance of all of the shares of common stock issuable upon conversion of the Notes and the Series B Preferred Stock in accordance with the rules and regulations of the Nasdaq Stock Market.

We additionally agreed that, subject to certain exceptions, without the consent of the holders holding at least a majority of our common stock underlying the Series B Preferred Stock and our common stock underlying the Notes for the period commencing on April 2, 2024 and ending on the date immediately following the 90th trading day after the Applicable Date (as defined in the Purchase Agreement), or the Restricted Period, neither we nor our subsidiaries shall directly or indirectly issue, offer, sell, grant any option or right to purchase, or otherwise dispose of (or announce any issuance, offer, sale, grant of any option or right to purchase or other disposition of) any equity security or any equity-linked or related security (including, without limitation, any equity security (as that term is defined under Rule 405 promulgated under the Securities Act of 1933, as amended), any Convertible Securities (as defined in the Purchase Agreement), any debt, any preferred stock or any purchase rights) (any such issuance, offer, sale, grant, disposition or announcement (whether occurring during the Restricted Period or at any time thereafter) is referred to as a Subsequent Placement).

Subject to the limitations described in the Purchase Agreement, for so long as the Notes are outstanding, we will be prohibited from effecting or entering into an agreement to effect any Subsequent Placement involving a Variable Rate Transaction (as defined in the Purchase Agreement). Additionally, the Purchase Agreement contains a participation right, which provides that, subject to certain exceptions, at any time on or prior to the fourth anniversary of April 2, 2024, neither we nor our subsidiaries shall, directly or indirectly, effect any Subsequent Placement unless we comply with the notice procedures as outlined in the Purchase Agreement with respect to each Buyer, providing the opportunity for such Buyer to participate in such Subsequent Placement on a pro rata basis as described in the Purchase Agreement.

Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2023

Accounting Policies [Abstract]

Consolidation, Policy [Policy Text Block]

Principles of Consolidation

Goodwill and Intangible Assets, Policy [Policy Text Block]

Intangible Assets and Goodwill

Based on our annual quantitative impairment assessment of our indefinite-lived IPR&D intangible assets as of December 1, 2023, we concluded that the assets were not impaired.

The following table represents identifiable intangible assets and goodwill as of December 31, 2023 and 2022:

	December 31,
(in thousands)	2023		2022

Istaroxime drug candidate	$	22,340	$	22,340
Rostafuroxin drug candidate		2,910		2,910
Intangible assets		25,250		25,250

Goodwill	$	-	$	3,058

Foreign Currency Transactions and Translations Policy [Policy Text Block]

Foreign Currency Transactions

Use of Estimates, Policy [Policy Text Block]

Use of Estimates

Cash and Cash Equivalents, Policy [Policy Text Block]

Cash and Cash Equivalents

Cash and cash equivalents are held at domestic and foreign financial institutions and consist of liquid investments and money market funds that are readily convertible into cash.

Concentration Risk, Credit Risk, Policy [Policy Text Block]

Concentration of Credit Risk

Fair Value of Financial Instruments, Policy [Policy Text Block]

Fair Value of Financial Instruments

Property, Plant and Equipment, Policy [Policy Text Block]

Property and Equipment

Cash and Cash Equivalents, Restricted Cash and Cash Equivalents, Policy [Policy Text Block]

Restricted Cash

Lessee, Leases [Policy Text Block]

Leases

Impairment or Disposal of Long-Lived Assets, Policy [Policy Text Block]

Long-lived Assets

Collaborative Arrangement, Accounting Policy [Policy Text Block]

Collaborative Arrangements

Severance Cost [Policy Text Block]

Severance

Restructured Debt Liability, Contingent Milestone Payment, Policy [Policy Text Block]

Restructured Debt Liability – Contingent Milestone Payment

Research and Development Expense, Policy [Policy Text Block]

Research and Development

Share-Based Payment Arrangement [Policy Text Block]

Stock-based Compensation

Derivatives, Policy [Policy Text Block]

Warrant Accounting

Income Tax, Policy [Policy Text Block]

Income Taxes

Earnings Per Share, Policy [Policy Text Block]

Net Loss per Common Share

We do not have any components of other comprehensive (loss) income.

Concentration of Suppliers [Policy Text Block]

Concentration of Suppliers

Segment Reporting, Policy [Policy Text Block]

Segment and Geographic Information

Note 2 - Basis of Presentation (Details Textual)	Feb. 24, 2023
Reverse Stock Split [Member]
Stockholders' Equity Note, Stock Split, Conversion Ratio	50

Note 4 - Accounting Policies - Intangible Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Jun. 30, 2023	Dec. 31, 2022
Intangible assets	$ 25,250		$ 25,250
Goodwill	0	$ 0	3,058
Istaroxime Drug Candidate [Member]
Intangible assets	22,340		22,340
Rostafuroxin Drug Candidate [Member]
Intangible assets	$ 2,910		$ 2,910

Consolidated Statements of Changes in Mezzanine Equity and Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	ATM Program [Member] Series A Preferred Stock, Mezzanine Equity [Member]	ATM Program [Member] Common Stock [Member]	ATM Program [Member] Additional Paid-in Capital [Member]	ATM Program [Member] Retained Earnings [Member]	ATM Program [Member] Treasury Stock, Common [Member]	ATM Program [Member]	Series A Preferred Stock, Mezzanine Equity [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Treasury Stock, Common [Member]	Total
Balance (in shares) at Dec. 31, 2021							0	565			0
Balance at Dec. 31, 2021							$ 0	$ 0	$ 830,259	$ (785,324)	$ (3,054)	$ 41,881
Net loss							$ 0	$ 0	0	(39,208)	$ 0	(39,208)
Issuance of stock (in shares)	0	207			0		39	0			0
Issuance of stock	$ 0	$ 0	$ 4,253	$ 0	$ 0	$ 4,253	$ 0	$ 0	0	0	$ 0	0
Stock-based compensation expense							$ 0	$ 0	3,086	0	$ 0	3,086
Balance (in shares) at Dec. 31, 2022							39	772			0
Balance at Dec. 31, 2022							$ 0	$ 0	837,598	(824,532)	$ (3,054)	10,012
Net loss							$ 0	$ 0	0	(20,291)	$ 0	(20,291)
Issuance of stock (in shares)	0	849			0		0	4,239			0
Issuance of stock	$ 0	$ 1	$ 754	$ 0	$ 0	$ 755	$ 0	$ 4	10,790	0	$ 0	10,794
Stock-based compensation expense							$ 0	$ 0	1,278	0	$ 0	1,278
Redemption of Series A Preferred Stock (in shares)							(39)	0			0
Vesting of restricted stock units (in shares)							0	2			0
Exercise of common stock warrants, net of expenses of $276 (in shares)							0	118			0
Exercise of common stock warrants, net of expenses of $276							$ 0	$ 1	842	0	$ 0	843
Reverse split adjustments - fractional share round ups (in shares)							0	17			0
Balance (in shares) at Dec. 31, 2023							0	5,997			0
Balance at Dec. 31, 2023							$ 0	$ 6	$ 851,262	$ (844,823)	$ (3,054)	$ 3,391

Note 7 - Accrued Expenses (Tables)

12 Months Ended

Dec. 31, 2023

Schedule of Accrued Liabilities [Table Text Block]

	December 31,
(in thousands)	2023		2022

Research and development	$	574	$	786
Professional fees		279		459
Severance		261		-
Salaries, bonus and benefits		64		123
Other		440		184
Total accrued expenses	$	1,618	$	1,552

Note 9 - Other Current Liabilities

12 Months Ended

Dec. 31, 2023

Other Liabilities Disclosure [Text Block]

Note 9 - Other Current Liabilities

In 2008, we entered into an Amended and Restated License Agreement with Philip Morris USA, Inc., or PMUSA, with respect to the U.S., or the U.S. License Agreement, and, as PMUSA had assigned its ex-U.S. rights to Philip Morris Products S.A., or PMPSA, effective on the same date and on substantially the same terms and conditions, we entered into a license agreement with PMPSA with respect to rights outside of the U.S., which we refer to, together with the U.S. License Agreement, as the PM License Agreements (See the section titled, “Note 13 – Collaboration, Licensing and Research Funding Agreements – Philip Morris USA Inc. and Philip Morris Products S.A.”)

Amendment No. 1 to the Amended and Restated License Agreement with Philip Morris USA for Aerosolization Technology

On January 16, 2024, we entered into Amendment No. 1 to the U.S. License Agreement, effective as of January 17, 2024, or the U.S. License Agreement Amendment, which amended the U.S. License Agreement. The U.S. License Agreement licenses U.S. intellectual property rights to us in respect of our former acute pulmonary care platform that was globally outlicensed to the Licensee in August 2022. Pursuant to the U.S. License Agreement Amendment, we agreed to pay PMUSA (i) $100,000 by January 18, 2024, (ii) $400,000 no later than the earlier of (a) July 1, 2024 or (b) the Company receiving a specified amount of net proceeds from debt or equity financings occurring on or after January 17, 2024 and (iii) up to an aggregate of $1.4 million upon the achievement of certain development and regulatory milestones, which milestone payments are expected to be funded from corresponding milestone payments received from the Licensee. Additionally, under the U.S. License Agreement Amendment, the parties extinguished and released their respective rights, obligations and claims in respect of quarterly payments under Section 7.3 of the U.S. License Agreement as in effect immediately prior to January 17, 2024. The U.S. License Agreement Amendment also grants PMUSA the right to terminate the U.S. License Agreement upon 30 days prior written notice to us if we have not paid a milestone payment to PMUSA by January 1, 2028.

Amendment No. 1 to the License Agreement with Philip Morris Products for Aerosolization Technology

On January 16, 2024, we also entered into Amendment No. 1 to the License Agreement with PMPSA, effective as of January 17, 2024, or the PMPSA License Amendment, which amended the License Agreement, dated March 28, 2008, between us and PMPSA, or the PMPSA License Agreement. The PMPSA License Agreement licenses ex-U.S. intellectual property to us in respect of our former acute pulmonary care platform that was globally outlicensed to the Licensee in August 2022. Pursuant to the PMPSA License Amendment, we agreed to pay PMPSA (i) $75,000 by January 19, 2024, or the Upfront Payment, (ii) $325,000 no later than the earlier of (a) July 1, 2024 or (b) the Company receiving a specified amount of net proceeds from debt or equity financings occurring on or after January 17, 2024 (together with the Upfront Payment, the Fixed Payments) and (iii) up to an aggregate of $1.4 million upon the achievement of certain development and regulatory milestones, which milestone payments are expected to be funded from corresponding milestone payments received from the Licensee. Additionally, but contingent upon our timely payment of the Fixed Payments, the parties extinguished and released their respective rights, obligations and claims in respect of quarterly payments under Section 6.2 of the PMPSA License Agreement as in effect immediately prior to January 17, 2024.

Accounting for the PMUSA and PMPSA Payments

We have accounted for these payments as a recognized subsequent event in accordance with applicable accounting guidance provided in ASC Topic 855, Subsequent Events. For the year ended December 31, 2023, we accrued $0.9 million for payments to PMUSA and PMPSA to be paid in 2024.

Note 16 - Income Taxes - Income Tax Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Income tax benefit, statutory rates	$ (4,261)	$ (8,521)
State taxes on income, net of federal benefit	(625)	903
Net operating loss expirations	5,875	3,485
Intangibles	613	2,561
Research and development tax credit	490	825
Foreign rate differential	37	196
Stock compensation	464	0
Employee related and other	(575)	467
Change in state tax rates	23,993	0
Other	0	(17)
Income tax expense / (benefit), statutory rates	26,011	(101)
Valuation allowance	(26,011)	(1,266)
Income tax benefit, net	$ (0)	$ (1,367)

Note 16 - Income Taxes - Benefit for Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Foreign	$ 0	$ (1,367)
Total deferred expense (benefit)	0	(1,367)
Income tax benefit, net	$ (0)	$ (1,367)

Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

Note 6 - Property and Equipment (Details Textual) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2022	Dec. 31, 2023	Dec. 31, 2022
Depreciation	$ 400	$ 82	$ 533

Note 2 - Basis of Presentation

12 Months Ended

Dec. 31, 2023

Basis of Accounting [Text Block]

Note 2 – Basis of Presentation

The consolidated financial statements are prepared in accordance with accounting principles generally accepted in the U.S., or US GAAP, and include accounts of Windtree Therapeutics, Inc. and its wholly owned subsidiaries. Intercompany balances and transactions have been eliminated in consolidation. All adjustments (consisting of normally recurring accruals) considered for fair presentation have been included.

The accompanying consolidated financial statements reflect the 1-for-50 reverse split of our common stock that was approved by our Board of Directors and stockholders and made effective on February 24, 2023. All share and per share information herein that relates to our common stock prior to the effective date has been retroactively restated to reflect the reverse stock split.

Note 17 - Leases

12 Months Ended

Dec. 31, 2023

Lessee, Operating Leases [Text Block]

Note 17 – Leases

Our operating leases consist primarily of facility leases for our operations in Warrington, Pennsylvania and Taipei, Taiwan.

We maintain our corporate headquarters and operations in Warrington, Pennsylvania. The facility serves as the main operating facility for drug development, regulatory, research and development, and administration. We also maintain offices in Taipei, Taiwan where we perform certain manufacturing development and preclinical activities.

In January 2021, we entered into a lease amendment to extend the term of our Warrington, Pennsylvania lease for a period of five years commencing on March 1, 2022 and expiring on February 28, 2027.

Throughout the term of our leases, we are responsible for paying certain variable lease costs, in addition to the rent, as specified in the lease, including a proportionate share of applicable taxes, operating expenses and utilities.

The following table contains a summary of the lease costs recognized under ASC 842 and other information pertaining to our operating leases for the years ended December 31, 2023 and 2022:

	Year Ended December 31,
(in thousands)	2023			2022

Operating lease cost	$	536		$	692
Variable lease cost		13			9
Sublease income		(44	)		-
Total lease cost	$	505		$	701

Other Information
Operating cash flows used for operating leases	$	559		$	730
Weighted average remaining lease term (in years)		3.2			4.1
Weighted average incremental borrowing rate		7.07	%		7.08	%

Future minimum lease payments under our non-cancelable operating leases as of December 31, 2023, are as follows:

(in thousands)	December 31, 2023

2024	$	531
2025		570
2026		581
2027		97
Total lease payments		1,779
Less imputed interest		(182	)
Total operating lease liabilities	$	1,597

Document And Entity Information - USD ($)	12 Months Ended
Document And Entity Information - USD ($)	Dec. 31, 2023	Apr. 01, 2024	Jun. 30, 2023
Document Information [Line Items]
Entity Central Index Key	0000946486
Entity Registrant Name	WINDTREE THERAPEUTICS INC /DE/
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2023
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2023
Document Transition Report	false
Entity File Number	001-39290
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	94-3171943
Entity Address, Address Line One	2600 Kelly Road, Suite 100
Entity Address, City or Town	Warrington
Entity Address, State or Province	PA
Entity Address, Postal Zip Code	18976-3622
City Area Code	215
Local Phone Number	488-9300
Title of 12(b) Security	Common Stock, $0.001 par value
Trading Symbol	WINT
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
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
ICFR Auditor Attestation Flag	false
Document Financial Statement Error Correction [Flag]	false
Entity Shell Company	false
Entity Public Float			$ 6,200,000
Entity Common Stock, Shares Outstanding		9,183,220
Auditor Firm ID	274
Auditor Name	EISNERAMPER LLP
Auditor Location	Philadelphia, Pennsylvania

Note 11 - Mezzanine Equity and Stockholders' Equity (Details Textual)							3 Months Ended		12 Months Ended
	Nov. 09, 2023 USD ($)	Aug. 15, 2023 shares	Apr. 24, 2023 USD ($) $ / shares shares	Feb. 21, 2023 USD ($) $ / shares shares	Jan. 20, 2023 USD ($) $ / shares shares	Nov. 17, 2022 $ / shares shares	Mar. 31, 2024 USD ($) shares	Dec. 31, 2023 USD ($) $ / shares shares	Dec. 31, 2023 USD ($) $ / shares shares	Dec. 31, 2022 USD ($) $ / shares shares	Dec. 31, 2020 shares	Sep. 17, 2020 USD ($)
Equity Issued During Period, Units, New Issues (in shares)			3,686,006
Units, Number of Warrants Called by Each Unit (in shares)			1
Units, Number of Securities Called by Each Unit (in shares)			1
Shares Issued, Price Per Share (in dollars per share) \| $ / shares			$ 2.93
Proceeds from Issuance or Sale of Equity, Gross \| $			$ 12,400,000
Proceeds from Issuance or Sale of Equity \| $			$ 10,800,000
Stock Issued During Period, Value, Exercise Of Warrants \| $									$ 843,000
Proceeds from Warrant Exercises \| $									$ 843,000	$ 0
Preferred Stock, Shares Authorized (in shares)						5,000,000		5,000,000	5,000,000	4,960,000
Preferred Stock, Par or Stated Value Per Share (in dollars per share) \| $ / shares						$ 0.001		$ 0.001	$ 0.001	$ 0.001
Proceeds from Issuance of Common Stock \| $									$ 755,000	$ 4,253,000
The 2020 Equity Incentive Plan [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Authorized (in shares)								700,000	700,000		31,000
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Additional Shares Authorized (in shares)		645,000
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant (in shares)								339,000	339,000	12,000
Series A Preferred Stock [Member]
Preferred Stock, Shares Authorized (in shares)						40,000
Preferred Stock, Par or Stated Value Per Share (in dollars per share) \| $ / shares						$ 0.001
Common Stock, Dividends, Shares Issued Per Share, Declared						0.001
Stock Dividends, Shares, Total (in shares)						38,610
Preferred Stock, Convertible, Conversion Price (in dollars per share) \| $ / shares						$ 0.01
Over-Allotment Option [Member]
Overallotment, Potential Issuable Shares (in shares)			552,900
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)			552,900
ATM Program [Member]
Stock Issued During Period, Shares, New Issues (in shares)								848,367		206,824
Proceeds from Issuance of Common Stock \| $								$ 800,000		$ 4,300,000
Shares Authorized to Be Offered and Sold Under Offering Agreement, Value \| $												$ 10,000,000
Proceeds from Issuance or Sale of Equity, Gross Amount \| $										4,400,000
ATM Program [Member] \| Forecast [Member]
Stock Issued During Period, Shares, New Issues (in shares)							2,576,153
Proceeds from Issuance of Common Stock \| $							$ 1,400,000
ATM Program [Member] \| Ladenburg [Member]
Commission Fee, Percent Fee	3.00%
Reimbursement, Maximum Disbursement \| $	$ 60,000
Reimbursement, Additional Maximum Quarterly Disbursement \| $	$ 3,000
April 2023 Warrant [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) \| $ / shares			$ 2.93
Warrants and Rights Outstanding, Term (Year)			5 years
December 2019 Warrants [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) \| $ / shares				$ 604.5	$ 604.5
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)				5,519	1,573
May 2020 Warrants [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) \| $ / shares				$ 398.75	$ 398.75
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)				5,517	5,598
March 2021 Warrants [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) \| $ / shares					$ 180
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)					89,001
January 2023 Existing Warrants [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) \| $ / shares					$ 10
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)					96,172
Stock Issued During Period, Value, Exercise Of Warrants \| $					$ 1,000,000
Proceeds from Warrant Exercises \| $				$ 700,000	$ 700,000
Fair Value of Warrant Modifications Related to Warrant Exercise Inducement \| $				$ 1,200,000					$ 1,238,000	0
January 2023 New Warrants [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) \| $ / shares					$ 10.76
Warrants and Rights Outstanding, Term (Year)					5 years
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)					192,344
July 2018 Warrants [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) \| $ / shares				$ 600
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)				1,250
December 2018 Warrants [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) \| $ / shares				$ 607.5
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)				9,960
February 2023 Existing Warrants [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) \| $ / shares				$ 7.06
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)				22,246
Stock Issued During Period, Value, Exercise Of Warrants \| $				$ 200,000
Proceeds from Warrant Exercises \| $				100,000
Fair Value of Warrant Modifications Related to Warrant Exercise Inducement \| $				$ 300,000					$ 274,000	$ 0
February 2023 New Warrants [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) \| $ / shares				$ 10.76
Warrants and Rights Outstanding, Term (Year)				5 years
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)				44,492

Note 11 - Mezzanine Equity and Stockholders' Equity - Common Shares Reserved for Future Issuance (Details) - $ / shares
shares in Thousands

12 Months Ended

Dec. 31, 2023

Dec. 31, 2022

Common stock, capital shares reserved for future issuance (in shares)

4,672

332

Investors - April 2023 Financing [Member]

Common stock, capital shares reserved for future issuance (in shares)

4,239

Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)

$ 2.93

February 2023 New Warrants [Member]

04/24/28

Common stock, capital shares reserved for future issuance (in shares)

Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)

$ 10.76

January 2023 New Warrants [Member]

07/21/28

Common stock, capital shares reserved for future issuance (in shares)

192

Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)

$ 10.76

Investors - March 2021 Financing [Member]

06/20/28

Common stock, capital shares reserved for future issuance (in shares)

185

Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)

$ 180

March 2021 Warrants [Member]

03/25/26

Common stock, capital shares reserved for future issuance (in shares)

Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)

$ 412.5

Investors - May 2020 Financing [Member]

02/09/24

Common stock, capital shares reserved for future issuance (in shares)

Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)

$ 399

Investors - December 2019 Financing [Member]

05/22/25

Common stock, capital shares reserved for future issuance (in shares)

Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)

$ 604.5

Investors - Aerosurf [Member]

12/06/24

Common stock, capital shares reserved for future issuance (in shares)

Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)

$ 0

Investors - December 2018 Financing - Long-term [Member]

02/14/24

Common stock, capital shares reserved for future issuance (in shares)

Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)

$ 607.5

Battelle - 2018 Payables Restructuring Agreement [Member]

12/04/23

Common stock, capital shares reserved for future issuance (in shares)

^[1]

Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)

^[1]

$ 975

Panacea Venture Management Company Ltd. [Member]

^[1]

12/07/23

Common stock, capital shares reserved for future issuance (in shares)

Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)

$ 600

LPH II Investments Limited [Member]

07/02/23

Common stock, capital shares reserved for future issuance (in shares)

Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)

$ 828

Investors - February 2017 Financing [Member]

04/04/25

Common stock, capital shares reserved for future issuance (in shares)

Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)

$ 4,110

Battelle 2014 Collaboration Agreement [Member]

02/15/24

Common stock, capital shares reserved for future issuance (in shares)

Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)

$ 210,000

10/10/24

[1]	See, Note 12 - Collaboration, Licensing and Research Funding Agreements, for further details on the Battelle collaboration agreement.

Note 12 - Stock Options and Stock-based Employee Compensation - Summary Stock Option Activity (Details) shares in Thousands	12 Months Ended
	Dec. 31, 2023 $ / shares shares
Shares Outstanding, Beginning Balance (in shares) \| shares	78
Weighted Average Exercise Price, Outstanding, at Beginning Period (in dollars per share) \| $ / shares	$ 381
Shares Granted (in shares) \| shares	213
Weighted Average Exercise Price, Granted (in dollars per share) \| $ / shares	$ 1.21
Shares Forfeited or Expired (in shares) \| shares	(14)
Weighted Average Exercise Price, Forfeited or Expired (in dollars per share) \| $ / shares	$ 259.02
Shares Outstanding, Ending Balance (in shares) \| shares	277
Weighted Average Exercise Price, Outstanding, at Ending Period (in dollars per share) \| $ / shares	$ 92.41
Weighted Average Remaining Contractual Life, Outstanding (Year)	8 years 9 months 18 days
Shares Vested and Exercisable (in shares) \| shares	56
Weighted Average Exercise Price, Vested and Exercisable (in dollars per share) \| $ / shares	$ 432.45
Weighted Average Remaining Contractual Life, Vested and Exercisable (Year)	5 years 10 months 24 days
Vested and expected to vest (in shares) \| shares	254
Weighted Average Exercise Price, Vested and Expected to Vest (in dollars per share) \| $ / shares	$ 94.53
Weighted Average Remaining Contractual Life, Vested and Expected to Vest (Year)	8 years 9 months 18 days

Note 10 - Restructured Debt Liability (Details Textual) - USD ($) $ / shares in Units, $ in Millions	Oct. 27, 2017	Dec. 31, 2023	Dec. 31, 2022
Liability for Contingent Milestone Payment, Noncurrent		$ 15.0	$ 15.0
Deerfield Loan [Member] \| Exchange and Termination Agreement [Member] \| Deerfield Management, L.P. [Member]
Extinguishment of Debt, Amount	$ 25.0
Class of Warrant or Right, Number of Warrants Cancelled (in shares)	167
Class of Warrant or Right, Exercise Price of Cancelled Warrants (in dollars per share)	$ 118,020
Repayments of Long-term Debt, Total	$ 2.5
Stock Issued During Period, Shares, Cancellation of Debt and Warrant Obligations (in shares)	474
Stock Issued During Period, Shares, Cancellation of Debt and Warrant Obligations, Percentage of Fully-diluted Shares Outstanding	2.00%
Liability for Contingent Milestone Payment, Noncurrent	$ 15.0	$ 15.0	$ 15.0

Note 7 - Accrued Expenses - Accrued Expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Research and development	$ 574	$ 786
Professional fees	279	459
Severance	261	0
Salaries, bonus and benefits	64	123
Other	440	184
Total accrued expenses	$ 1,618	$ 1,552

Note 17 - Leases (Tables)

12 Months Ended

Dec. 31, 2023