Income taxes (Tables)

12 Months Ended

Dec. 31, 2022

Income tax recovery varies from the amounts that would be computed by applying the expected U.S. federal income tax rate (21%) as shown in the following table:


	December 31,
	2022			2021


Statutory federal income tax rate		(21.0	)%		(21.0	)%
Stock-based compensation		2.2			2.0
Change in valuation allowance		21.4			21.2
Tax credits		(2.6	)		(2.2	)

Income tax recovery		—	%		—	%

Schedule of Net (Loss) Income Before Taxes


Net loss before taxes (in thousands):	Years Ended December 31,
	2022			2021

U.S.		(57,578	)		(60,692	)

Total	$	(57,578	)	$	(60,692	)

Components of Deferred Income Tax Assets

Deferred income tax assets and liabilities result from the temporary differences between the amount of assets and liabilities recognized for financial statement and income tax purposes. The significant components of the deferred income tax assets are as follows (in thousands):


	December 31,
	2022			2021

Deferred tax assets:
U.S. net operating losses	$	26,362		$	22,863
Research and development deductions and credits		3,931			2,414
Intangibles		446			457
Lease liability		2,456			2,701
Stock-based compensation		2,274			1,695
Capitalized research and development		6,920			—
Other		168			186

Total deferred tax assets:		42,557			30,316
Deferred income tax liabilities
Right-of-use assets		2,040			2,261
Other		410			287

Total deferred tax liabilities		2,450			2,548

Net deferred income tax assets		40,107			27,768
Less: valuation allowance		(40,107	)		(27,768	)

Deferred tax assets, net of valuation allowance	$	—		$	—