Income Taxes (Tables)

12 Months Ended

Dec. 31, 2021

Income Tax Disclosure [Abstract]

Schedule of Components of Income Tax Expense (Benefit)

The components of income tax expense (benefit) were as follows (in thousands):

	Year Ended December 31,
	2021		2020
Current
Federal	$	—	$	—
State	—		—
Foreign	1,600		—
Total current	1,600		—
Deferred
Federal	—		—
State	—		—
Foreign	—		—
Total deferred	—		—
Total income tax expense (benefit)	$	1,600	$	—

Summary of Reconciliation of Income Tax Expense (Benefit)

A reconciliation of income tax expense (benefit) to the amount computed by applying the statutory federal income tax rate to the loss from operations is summarized as follows (in thousands):

	Year Ended December 31,
	2021		2020
Income tax benefit at statutory rate	$	(27,189)	$	(20,699)
State income tax, net of federal benefit	(7,065)		(6,823)
Permanent items	348		8
Stock-based compensation	174		215
Orphan drug credit	(1,827)		(2,544)
Research and development credits	(2,489)		(863)
Uncertain tax positions	1,125		785
Change in state rate	910		74
Change in valuation allowance	36,284		28,090
Other	1,329		1,757
	$	1,600	$	—

Significant Components of Deferred Tax Assets

Significant components of the Company’s deferred tax assets are shown below (in thousands):

	As of December 31,
	2021		2020
Deferred tax assets:
Net operating loss carryforwards	$	70,903	$	51,398
Research and development and orphan drug credits	12,061		8,662
Accrued expenses	921		936
Intangibles	31		43
Operating lease liabilities	411		562
Derivative liability	30,491		16,700
Other, net	615		628
Total deferred tax assets	115,433		78,929
Deferred tax liabilities:
Operating lease right-of-use assets	(390)		(540)
Property and equipment, net	(694)		(324)
Total deferred tax liabilities	(1,084)		(864)
Net deferred tax assets before valuation allowance	114,349		78,065
Valuation allowance	(114,349)		(78,065)
Net deferred tax assets	$	—	$	—

Summary of Activity Related to Gross Unrecognized Tax Benefits

The following table summarizes the activity related to the Company’s gross unrecognized tax benefits (in thousands):

	Year Ended December 31
	2021		2020
Gross unrecognized tax benefits at the beginning of the year	$	3,345	$	2,560
Increases related to current year positions	1,236		871
Increases related to prior year positions	55		—
Decreases related to prior year positions	—		(86)
Expiration of unrecognized tax benefits	—		—
Gross unrecognized tax benefits at the end of the year	$	4,636	$	3,345