Income Taxes (Tables)

12 Months Ended

Dec. 31, 2021

Income Tax Disclosure [Abstract]

Schedule of Domestic and Foreign Components of Income (Loss) before Income Taxes

The following table presents domestic and foreign components of income (loss) before income taxes for the periods presented (in thousands):

	December 31,
	2021			2020
United States	$	(66,464	)	$	(49,961	)
Foreign		(2,740	)		(1,941	)
	$	(69,204	)	$	(51,902	)

Schedule of Components of Provision for Income Taxes

The components of the provision for income taxes related to Korean withholding taxes on the near-term milestone payment the Company received pursuant to the Hanmi Agreement are as follows (in thousands):

	December 31,
	2021		2020
Current
Foreign		—	$	990
Total provision for income taxes	$	—	$	990

Schedule of Effective Income Tax Rate Reconciliation

A reconciliation of the statutory U.S. federal rate and effective rate is as follows:

	December 31,
	2021			2020
Federal tax		21.00	%		21.00	%
Stock-based compensation		(0.76	)		(0.55	)
Research and development tax credit		2.39			2.83
Foreign losses not benefited		(2.14	)		—
Withholding taxes, net of federal benefit		—			(1.51	)
Change in valuation allowance		(20.86	)		(23.99	)
Other		0.37			0.31
Income tax expense		—	%		(1.91	%)

Schedule of Components of Deferred Tax Assets and Liabilities

The components of the Company’s deferred tax assets and liabilities are as follows (in thousands):

	December 31,
	2021			2020
Deferred tax assets:
Net operating loss carryforwards	$	49,791		$	38,665
Federal and state research and development tax credits		7,756			6,103
Accrued liabilities and reserves		1,644			1,089
Stock-based compensation		2,331			1,273
Gross deferred tax assets		61,522			47,130
Valuation allowance		(61,488	)		(47,060	)
Deferred tax liabilities:
Depreciation and amortization		(34	)		(70	)
Gross deferred tax liabilities		(34	)		(70	)
Net deferred taxes	$	—		$	—

Schedule of Reconciliation of Unrecognized Tax Benefits

A reconciliation of the beginning and ending amounts of unrecognized tax benefits for the years ended December 31, 2021 and 2020 resulting primarily from research and development tax credits claimed for both US and foreign operations on the Company’s annual tax returns were as follows (in thousands):

	December 31,
	2021		2020
Balance at beginning of year	$	2,291	$	1,747
Additions on tax positions related to prior years		807		—
Additions on tax positions related to current year		1,336		544
Balance at end of year	$	4,434	$	2,291