Note 3 - Balance Sheet Components (Tables)

12 Months Ended

Dec. 31, 2021

Notes Tables

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

	December 31,
	2021		2020
Preclinical and clinical	$	3,288	$	870
Clinical research organization receivable		—		262
Lease receivable		33		—
Other		—		16
Total	$	3,321	$	1,148

Property, Plant and Equipment [Table Text Block]

	December 31,
	2021			2020
Equipment and furniture	$	1,430		$	1,416
Buildings, leasehold and building improvements		2,673			2,673
		4,103			4,089
Less: Accumulated depreciation and amortization		(2,699	)		(2,559	)
Accumulated impairment loss		(1,004	)		(1,004	)
Property and equipment, net	$	400		$	526

Schedule of Accrued Liabilities [Table Text Block]

	December 31,
	2021		2020
Payroll and related	$	1,397	$	1,052
Preclinical and clinical		6,727		707
Prepaid sublease		227		—
Professional services		50		169
Other		15		395
Total	$	8,416	$	2,323