Income taxes (Tables)

12 Months Ended

Dec. 31, 2021

Income Tax Disclosure [Abstract]

Schedule of Components of Current Provision for Income Taxes

The components of the current provision for income taxes were as follows for the years ended December 31, 2021 and 2020:

(in thousands)	2021		2020
Current:
State	$	—	$	1
Federal		—		—
Foreign		143		160
Total current provision for income taxes	$	143	$	161
Deferred:
State	$	—	$	—
Federal		—		—
Foreign		—		—
Total deferred provision for income taxes	$	—	$	—

Schedule of Expected Income Tax (Benefit) Computed Using Federal Statutory Income Tax Rate to Company's Effective Income Tax Rate

A reconciliation of the expected income tax (benefit) computed using the federal statutory income tax rate to the Company’s effective income tax rate is as follows for the years ended December 31, 2021 and 2020:

	2021			2020
Income tax computed at federal statutory rate		21.00	%		21.00	%
State taxes, net of federal benefit		6.91	%		6.90	%
R&D credit carryovers		0.90	%		1.40	%
Change in valuation allowance		-27.42	%		-27.24	%
Stock based compensation		-1.19	%		-0.24	%
Permanent differences		-0.31	%		0.27	%
Change in fair value of derivatives		0.00	%		-2.25	%
Effective income tax rate		-0.11	%		-0.15	%

Schedule of Deferred Tax Assets And Liabilities

The components of the deferred tax assets and liabilities were as follows at December 31:

(in thousands)	2021			2020
Deferred tax assets:
Net operating loss carryforward	$	72,425		$	41,930
Operating lease liabilities		4,622			4,453
Tax credits		6,177			4,639
Other accruals and reserves		1,461			1,558
Stock-based compensation		1,216			209
Deferred revenue		2,140			—
Other		22			10
		88,063			52,799
Valuation allowance		(84,288	)		(49,133	)
Net deferred tax assets	$	3,775		$	3,666
Deferred tax liabilities:
Right of use assets	$	(3,205	)	$	(2,857	)
Stock-based compensation		—			—
Property and equipment		(570	)		(809	)
Total deferred tax liabilities	$	(3,775	)	$	(3,666	)
Total deferred income taxes	$	—		$	—

Summary of Changes to Unrecognized Tax Benefits

:

(in thousands)	2021		2020
Balance, beginning of the period	$	1,536	$	637
Increase related to prior year positions		63		131
Increase related to current year positions		842		768
Balance, ending of the period	$	2,441	$	1,536