Income Taxes (Tables)

12 Months Ended

Dec. 31, 2021

Income Taxes

Summary of Significant components of the Company's deferred tax assets

	December 31,
	2021		2020
Deferred tax assets
Net operating loss carryforwards	$	47,737	$	39,937
Research and development credits		623		747
Depreciation and amortization		(89)		239
Accrued expenses and other		1,356		611
Inventory reserve		171		205
Gross deferred tax asset		49,798		41,739
Valuation allowance		(49,798)		(41,739)
Net deferred tax asset	$	—	$	—

Schedule of Company's net operating loss (NOL) carryforwards

	December 31,
	2021		2020
NOL carryforwards
Federal	$	181,443	$	150,642
State		151,488		128,912

Schedule of reconciliation of income tax benefit

	Year ended December 31,
	2021		2020		2019
Rate reconciliation
Federal tax benefit at statutory rate	(21.0)	%	(21.0)	%	(21.0)	%
State rate, net of federal benefit	(3.5)		(4.2)		(2.9)
Permanent differences	0.2		0.6		0.4
Research and development	0.4		0.7		(0.7)
Change in valuation allowance	24.2		24.0		24.2
Other	(0.3)		(0.1)		—
Total tax provision	—	%	—	%	—	%