Note 4 - Balance Sheet Components (Tables)

9 Months Ended

Sep. 30, 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
September 30, 2021
Cash at banks	$	93,955	$	—	$	—		$	93,955	$	93,955	$	—	$	—
Money market funds		73,276		—		—			73,276		73,276		—		—
U.S. Treasury securities		23,025		—		(3	)		23,022		—		9,997		13,025
Commercial paper		7,192		—		—			7,192		—		7,192		—
Corporate debt securities		6,506		—		—			6,506		—		3,249		3,257
Total	$	203,954	$	—	$	(3	)	$	203,951	$	167,231	$	20,438	$	16,282

	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]

	September 30, 2021			December 31, 2020
Laboratory equipment	$	3,389		$	1,759
Office and computer equipment		382			294
Leasehold improvements		1,057			—
Construction in progress		1,578			—
Total property and equipment		6,406			2,053
Less: accumulated depreciation		(979	)		(573	)
Property and equipment, net	$	5,427		$	1,480

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

	September 30, 2021		December 31, 2020
Facilities	$	12,237	$	6,836
Office equipment		—		2
Right-of-use assets, net	$	12,237	$	6,838

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

	September 30, 2021			December 31, 2020
Developed technology	$	20,300		$	20,300
Intellectual property		80			80
Total cost		20,380			20,380
Less: accumulated amortization		(6,318	)		(5,019	)
Intangible assets, net	$	14,062		$	15,361

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

Year Ending December 31,	Amount
2021 (three months remaining)	$	433
2022		1,731
2023		1,732
2024		1,732
2025		1,731
Thereafter		6,703
Total	$	14,062

Schedule of Accrued Liabilities [Table Text Block]

	September 30, 2021		December 31, 2020
Accrued compensation	$	2,084	$	1,618
Accrued clinical and manufacturing expenses		725		1,772
Accrued professional and consulting services		782		777
Other liabilities, current portion		796		632
Total	$	4,387	$	4,799