Income Taxes (Tables)

12 Months Ended

Dec. 31, 2023

Schedule of Effective Income Tax Rate Reconciliation

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


	December 31,
	2023		2022
Tax at federal statutory rate	21.0	%	21.0	%
State taxes, net of federal benefit	4.5	%	7.2	%
Research and development tax credit	1.8	%	1.4	%
Stock-based compensation	(0.8)	%	(1.9)	%
Nondeductible interest expense	(0.5)	%	(0.5)	%
FIN 48 reserve	(0.3)	%	(0.2)	%
Change in valuation allowance	(23.3)	%	(26.8)	%
Other	(2.4)	%	(0.2)	%
Total	—	%	—	%

Schedule of Deferred Tax Assets and Liabilities

The tax effects of temporary differences that give rise to significant components of the deferred tax assets and liabilities are as follows (in thousands):


	December 31,
	2023		2022
Deferred tax assets:
Net operating loss carryforwards	$	41,864	$	40,884
Research and development credits	13,069		12,088
Research and development expenditures, capitalized for tax	8,271		4,563
Fixed assets and inventory	151		159
Accruals and reserves	1,633		1,180
Interest expense carryforward	5,033		3,850
Operating lease liability	3,958		4,442
Other	1,718		1,521
Gross deferred tax assets	75,697		68,687
Deferred tax liabilities:
Operating lease right-of-use asset	(3,436)		(3,910)
Total deferred tax liabilities	(3,436)		(3,910)
Valuation allowance	(72,261)		(64,777)
Net deferred tax assets	$	—	$	—

Schedule of Unrecognized Tax Benefits Roll Forward

A reconciliation of the beginning and ending unrecognized tax benefit amount is as follows (in thousands):


	Year Ended December 31,
	2023		2022
Beginning balance	$	1,601	$	1,489
Increase in balance related to tax positions taken during the current year	136		112
Decrease in balance related to tax positions taken during prior years	(7)		—
Ending balance	$	1,730	$	1,601