Note 5 - Balance Sheet Components (Tables)

12 Months Ended

Dec. 31, 2021

Notes Tables

Cash, Cash Equivalents and Investments [Table Text Block]

	Amortized		Gross Unrealized					Estimated		Cash and Cash		Short-Term		Long-Term
	Cost		Gains		Losses			Fair Value		Equivalents		Investments		Investments
December 31, 2021
Cash at banks	$	72,767	$	—	$	—		$	72,767	$	72,767	$	—	$	—
Money market funds		70,978		—		—			70,978		70,978		—		—
U.S. Treasury securities		25,055		—		(58	)		24,997		—		12,022		12,975
Commercial paper		7,491		—		—			7,491		—		7,491		—
Corporate debt securities		6,480		—		(16	)		6,464		—		3,229		3,235
Total	$	182,771	$	—	$	(74	)	$	182,697	$	143,745	$	22,742	$	16,210

	Amortized		Gross Unrealized				Estimated		Cash and Cash		Short-Term		Long-Term
	Cost		Gains		Losses		Fair Value		Equivalents		Investments		Investments
December 31, 2020
Cash at banks	$	66,865	$	—	$	—	$	66,865	$	66,865	$	—	$	—
Money market funds		60,005		—		—		60,005		60,005		—		—
Total	$	126,870	$	—	$	—	$	126,870	$	126,870	$	—	$	—

Property, Plant and Equipment [Table Text Block]

	December 31, 2021			December 31, 2020
Laboratory equipment	$	5,057		$	1,759
Office and computer equipment		481			294
Leasehold improvements		1,063			—
Construction in progress		1,305			—
Total property and equipment		7,906			2,053
Less: accumulated depreciation		(1,305	)		(573	)
Property and equipment, net	$	6,601		$	1,480

Lessee, Operating Lease, Right-of-Use Assets [Table Text Block]

	December 31, 2021		December 31, 2020
Facilities	$	13,168	$	6,836
Office equipment		—		2
Right-of-use assets, net	$	13,168	$	6,838

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

	December 31, 2021			December 31, 2020
Developed technology	$	10,600		$	20,300
Intellectual property		80			80
Total cost		10,680			20,380
Less: accumulated amortization		(56	)		(5,019	)
Intangible assets, net	$	10,624		$	15,361

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

Year Ending December 31,	Amount
2022	$	1,350
2023		1,350
2024		1,350
2025		1,350
2026		1,350
Thereafter		3,874
Total	$	10,624

Schedule of Accrued Liabilities [Table Text Block]

	December 31, 2021		December 31, 2020
Accrued compensation	$	2,786	$	1,618
Accrued clinical and manufacturing expenses		986		1,772
Accrued professional and consulting services		556		777
Other liabilities, current portion		736		632
Total	$	5,064	$	4,799