Note 3 - Balance Sheet Components (Tables)

12 Months Ended

Dec. 31, 2022

Notes Tables

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

	December 31,
	2022		2021
Clinical	$	4,196	$	3,288
Lease receivable		85		33
Total	$	4,281	$	3,321

Property, Plant and Equipment [Table Text Block]

	December 31,
	2022			2021
Equipment and furniture	$	1,441		$	1,430
Buildings, leasehold and building improvements		2,673			2,673
		4,114			4,103
Less: Accumulated depreciation and amortization		(2,840	)		(2,699	)
Accumulated impairment loss		(1,004	)		(1,004	)
Property and equipment, net	$	270		$	400

Schedule of Accrued Liabilities [Table Text Block]

	December 31,
	2022		2021
Payroll and related	$	1,930	$	1,397
Clinical		4,730		6,727
Sublease prepayment		—		227
Professional services		78		50
Other		—		15
Total	$	6,738	$	8,416