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

6 Months Ended

Jun. 30, 2023

Notes Tables

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

	June 30, 2023		December 31, 2022
Prepaid insurance and other	$	1,220	$	1,028
Prepaid sponsored research		1,073		600
Vendor prepayments and deposits		903		801
Non-trade receivables		7		2
Related party receivables		5		20
Total prepaid expenses and other current assets	$	3,208	$	2,451

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 June 30, 2023:	$	2	$	—	$	—	$	2
Fair value of warrant liability as of December 31, 2022:	$	77	$	—	$	—	$	77

Three Months Ended June 30, 2023	Warrant Liability Long-Term
Balance, March 31, 2023	$	38
Change in fair value - net		(36	)
Balance, June 30, 2023	$	2

Six Months Ended June 30, 2023	Warrant Liability Long-Term
Balance, December 31, 2022	$	77
Change in fair value - net		(75	)
Balance, June 30, 2023	$	2