Income Taxes (Tables)

12 Months Ended

Dec. 31, 2019

Income Tax Disclosure [Abstract]

Schedule of Components of Income Tax Expense (Benefit)

The components of income before taxes are as follows (in thousands):

	Year Ended December 31,
	2019		2018
United States	$	(52,415)	$	(37,630)
International	—		—
	$	(52,415)	$	(37,630)

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 (in thousands):

	Year Ended December 31,
	2019		2018
Tax at federal statutory rate	$	(11,007)	$	(7,902)
State taxes, net of federal benefit	(2,270)		(1,582)
Permanent differences	(4,731)		289
Loss on Series C warrant liability	5,330		2,500
Change in valuation allowance	12,797		6,197
General business credits	(319)		136
Other	208		376
Provision for income taxes	$	8	$	14

Schedule of Deferred Tax Assets and Liabilities

Significant components of the Company’s net deferred tax assets as of December 31, 2019 and 2018 consist of the following (in thousands):

	December 31,
	2019		2018
Deferred tax assets:
Net operating loss carryforwards	$	44,574	$	33,815
Research and development credits	5,287		4,944
Capitalized start-up costs/Intangibles	11		16
Accruals and reserves	2,227		1,169
Property and equipment	188		82
Stock-based compensation	568		274
Operating lease liability	1,133		—
Total deferred tax assets	53,988		40,300
Less: Valuation allowance	(53,126)		(40,300)
Deferred tax liabilities:
Operating lease asset	(862)		—
Total deferred tax liabilities	(862)		—
Net deferred tax assets	$	—	$	—

Reconciliation of Unrecognized Tax Benefits

A reconciliation of the unrecognized tax benefits from January 1, 2018 to December 31, 2019 is as follows (in thousands):

	December 31,
	2019		2018
Balance at the beginning of year	$	1,348	$	615
Increases related to current years’ tax positions	88		118
Increases/(decreases) related to prior years’ tax positions	—		615
Balance at end of year	$	1,436	$	1,348