Income Taxes (Tables)

12 Months Ended

Dec. 31, 2021

Schedule of Temporary Differences Between Basis of Deferred Tax Assets and Liabilities

Deferred taxes are recognized for temporary differences between the basis of assets and liabilities for financial statement and income tax purposes. Deferred tax assets consist of the following (in thousands):

	December 31,
	2021			2020
Deferred tax assets:
Net operating loss carryforwards	$	76,802		$	61,181
Tax credit carryforwards		7,248			5,748
Accrued expenses		181			126
Property and equipment		591			279
Lease liabilities		5,618			6,230
Equity compensation		2,396			2,200
Amortizable intangibles		1,197			1,195
Other		238			74
Gross deferred tax assets		94,271			77,033
Deferred tax liabilities:
Right of use assets		(3,794	)		(4,242	)
Gross deferred tax liabilities		(3,794	)		(4,242	)
Valuation allowance		(90,477	)		(72,791	)
Net deferred tax assets	$	—		$	—

Reconciliation of Statutory Federal Income Tax Rate to Company's Effective Income Tax Rate

A reconciliation of the statutory federal income tax rate to the Company’s effective income tax rate is as follows:

	Years ended December 31,
	2021			2020
	Tax Rate			Tax Rate
U.S. federal statutory rate		21	%		21	%
State income taxes, net of federal benefit		6	%		6	%
Other permanent differences		0	%		(1	)%
Tax credits		2	%		2	%
Other items		0	%		4	%
Net change in valuation allowance		(29	)%		(32	)%
Effective income tax rate		—			—

Schedule of Valuation Allowance

A roll-forward of the valuation allowance for the years ended December 31, 2021 and 2020 is as follows (in thousands):

	Years ended December 31,
	2021			2020
Balance at beginning of year	$	(72,791	)	$	(53,834	)
Increase in valuation allowance		(17,686	)		(18,957	)
Balance at end of year	$	(90,477	)	$	(72,791	)