Note 2 - Basis of Presentation, Principles of Consolidation, and Significant Accounting Policies and Liquidity (Tables)

9 Months Ended

Sep. 30, 2025

Notes Tables

Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Table Text Block]

	September 30, 2025		December 31, 2024
Prepaid insurance	$	786	$	554
Vendor prepayments and deposits		367		331
Prepaid sponsored research		23		11
Related party receivables		4		4
Non-trade receivables		2		16
Total prepaid expenses and other current assets	$	1,182	$	916

Fair Value Measurements, Recurring and Nonrecurring [Table Text Block]

Description	Fair Value		Level 1		Level 2		Level 3
Fair value of warrant liability as of September 30, 2025:	$	41,333	$	—	$	—	$	41,333
Fair value of warrant liability as of December 31, 2024:	$	—	$	—	$	—	$	—

Three Months Ended September 30, 2025	Warrant Liability Long-Term
Balance, June 30, 2025	$	16,830
Warrants issued		30,585
Warrants exercised		(4,491	)
Change in fair value - net		(1,591	)
Balance, September 30, 2025	$	41,333

Nine Months Ended September 30, 2025	Warrant Liability Long-Term
Balance, December 31, 2024	$	—
Warrants issued		46,855
Warrants exercised		(4,491	)
Change in fair value - net		(1,031	)
Balance, September 30, 2025	$	41,333

Accounting Standards Update and Change in Accounting Principle [Table Text Block]

	September 30, 2025									December 31, 2024
				As Reported			Effect of			As Reported			As Adjusted			Effect of
	Under Old Policy			Under New Policy			Change			Under Old Policy			Under New Policy			Change
Condensed Consolidated Balance Sheets
Warrant liability - long-term	$	48,660		$	41,333		$	(7,327	)	$	5,229		$	—		$	(5,229	)
Total liabilities		54,600			47,273			(7,327	)		10,946			5,717			(5,229	)
Additional paid-in capital		162,337			194,631			32,294			159,384			183,690			24,306
Accumulated deficit		(196,589	)		(221,556	)		(24,967	)		(153,367	)		(172,444	)		(19,077	)
Total stockholders' equity (deficit)		(34,247	)		(26,920	)		7,327			5,979			11,208			5,229
Total liabilities and stockholders' equity (deficit)		20,353			20,353			—			16,925			16,925			—

	March 31, 2025									June 30, 2025
	As Reported			As Adjusted			Effect of			As Reported			As Adjusted			Effect of
	Under Old Policy			Under New Policy			Change			Under Old Policy			Under New Policy			Change
Condensed Consolidated Balance Sheets
Warrant liability - long-term	$	13,749		$	—		$	(13,749	)	$	20,553		$	16,973		$	(3,580	)
Total liabilities		20,971			7,222			(13,749	)		28,758			25,178			(3,580	)
Additional paid-in capital		159,869			192,163			32,294			160,286			192,580			32,294
Accumulated deficit		(159,803	)		(178,348	)		(18,545	)		(167,443	)		(196,157	)		(28,714	)
Total stockholders' equity (deficit)		42			13,791			13,749			(7,165	)		(3,585	)		3,580
Total liabilities and stockholders' equity (deficit)		21,013			21,013			—			21,593			21,593			—

	Three Months Ended								Three Months Ended
	September 30, 2025								September 30, 2024
				As Reported			Effect of		As Reported			As Adjusted			Effect of
	Under Old Policy			Under New Policy			Change		Under Old Policy			Under New Policy			Change
Condensed Consolidated Statement of Operations
Gain (loss) from change in fair value of warrant liability	$	(2,157	)	$	1,591		$	3,748	$	(1,728	)	$	—		$	1,728
Transaction costs allocated to warrant liabilities		(530	)		(530	)		—		(993	)		—			993
Loss on issuance of warrant liabilities		(20,609	)		(20,609	)		—		(847	)		—			847
Net loss		(29,147	)		(25,399	)		3,748		(10,592	)		(7,024	)		3,568
Net loss per common share - basic and diluted		(0.78	)		(0.68	)		0.10		(2.85	)		(1.89	)		0.96
Other comprehensive income (loss)		(29,153	)		(25,405	)		3,748		(10,578	)		(7,010	)		3,568

	Nine Months Ended									Nine Months Ended
	September 30, 2025									September 30, 2024
				As Reported			Effect of			As Reported			As Adjusted			Effect of
	Under Old Policy			Under New Policy			Change			Under Old Policy			Under New Policy			Change
Condensed Consolidated Statement of Operations
Gain (loss) from change in fair value of warrant liability	$	16,506		$	1,031		$	(15,475	)	$	1,423		$	—		$	(1,423	)
Transaction costs allocated to warrant liabilities		(3,525	)		(1,737	)		1,788			(993	)		—			993
Loss on issuance of warrant liabilities		(38,760	)		(30,962	)		7,798			(847	)		—			847
Net loss		(43,223	)		(49,112	)		(5,889	)		(19,881	)		(19,464	)		417
Net loss per common share - basic and diluted		(2.08	)		(2.36	)		(0.28	)		(6.83	)		(6.69	)		0.14
Other comprehensive income (loss)		(43,226	)		(49,115	)		(5,889	)		(19,868	)		(19,451	)		417

	Three Months Ended									Three Months Ended
	June 30, 2025									June 30, 2024
	As Reported			As Adjusted			Effect of			As Reported			As Adjusted			Effect of
	Under Old Policy			Under New Policy			Change			Under Old Policy			Under New Policy			Change
Condensed Consolidated Statement of Operations
Gain (loss) from change in fair value of warrant liability	$	9,609		$	(560	)	$	(10,169	)	$	1,696		$	—		$	(1,696	)
Transaction costs allocated to warrant liabilities		(1,207	)		(1,207	)		—			—			—			—
Loss on issuance of warrant liabilities		(10,352	)		(10,352	)		—			—			—			—
Net loss		(7,640	)		(17,809	)		(10,169	)		(4,319	)		(6,015	)		(1,696	)
Net loss per common share - basic and diluted		(0.49	)		(1.15	)		(0.66	)		(1.70	)		(2.37	)		(0.67	)
Other comprehensive loss		(7,640	)		(17,809	)		(10,169	)		(4,311	)		(6,007	)		(1,696	)

	Six Months Ended									Six Months Ended
	June 30, 2025									June 30, 2024
	As Reported			As Adjusted			Effect of			As Reported			As Adjusted			Effect of
	Under Old Policy			Under New Policy			Change			Under Old Policy			Under New Policy			Change
Condensed Consolidated Statement of Operations
Gain (loss) from change in fair value of warrant liability	$	18,663		$	(560	)	$	(19,223	)	$	3,151		$	—		$	(3,151	)
Transaction costs allocated to warrant liabilities		(2,995	)		(1,207	)		1,788			—			—			—
Loss on issuance of warrant liabilities		(18,150	)		(10,352	)		7,798			—			—			—
Net loss		(14,076	)		(23,713	)		(9,637	)		(9,289	)		(12,440	)		(3,151	)
Net loss per common share - basic and diluted		(1.13	)		(1.90	)		(0.77	)		(3.71	)		(4.97	)		(1.26	)
Other comprehensive loss		(14,073	)		(23,710	)		(9,637	)		(9,290	)		(12,441	)		(3,151	)

	Three Months Ended									Three Months Ended
	March 31, 2025									March 31, 2024
	As Reported			As Adjusted			Effect of			As Reported			As Adjusted			Effect of
	Under Old Policy			Under New Policy			Change			Under Old Policy			Under New Policy			Change
Condensed Consolidated Statement of Operations
Gain from change in fair value of warrant liability	$	9,054		$	—		$	(9,054	)	$	1,455		$	—		$	(1,455	)
Transaction costs allocated to warrant liabilities		(1,788	)		—			1,788			—			—			—
Loss on issuance of warrant liabilities		(7,798	)		—			7,798			—			—			—
Net loss		(6,436	)		(5,904	)		532			(4,970	)		(6,425	)		(1,455	)
Net loss per common share - basic and diluted		(0.69	)		(0.63	)		0.06			(2.02	)		(2.61	)		(0.59	)
Other comprehensive loss		(6,433	)		(5,901	)		532			(4,979	)		(6,434	)		(1,455	)