Note 4 - Balance Sheet Components (Tables)

12 Months Ended

Dec. 31, 2022

Notes Tables

Schedule of Inventory, Current [Table Text Block]

	Year Ended December 31,
	2022		2021
Raw materials	$	—	$	2,010
Work in process		—		1,371
Finished goods		—		2,443
Total inventory	$	—	$	5,824

Property, Plant and Equipment [Table Text Block]

	December 31,
	2022			2021
Leasehold improvements	$	2,519		$	2,519
Laboratory equipment		1,118			1,019
Furniture, fixtures and equipment		966			932
Software		289			202
Construction in progress		22			186
		4,914			4,858
Less: Accumulated depreciation and amortization		(2,953	)		(2,396	)
	$	1,961		$	2,462

Schedule of Finite-Lived Intangible Assets [Table Text Block]

	December 31,
	2022			2021
Acquired patents and licenses	$	7,985		$	7,985
Less: Accumulated amortization		(5,434	)		(4,769	)
	$	2,551		$	3,216

Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block]

Years ending December 31:
2023	$	665
2024		665
2025		665
2026		556
	$	2,551

Schedule of Accrued Liabilities [Table Text Block]

	December 31,
	2022		2021
Compensation expense	$	1,377	$	2,932
Controlled launch (Note 8)		—		534
Director and officer liability insurance (Note 12)		571		—
Clinical trial fees and costs		64		245
Professional fees		318		85
Warranty		50		80
Other		215		513
	$	2,595	$	4,389