Income Taxes (Tables)

12 Months Ended

Dec. 31, 2021

Income Tax Disclosure [Abstract]

Effective Income Tax Rate Reconciliation

A reconciliation between income tax benefit and the expected tax benefit at the statutory rate for the years ended December 31, 2021, 2020, and 2019 are as follows:

	For the Year Ended December 31,
	2021		2020		2019
Statutory federal income tax rate	21.0	%	21.0	%	21.0	%
State income taxes, net of federal benefit	6.2	%	6.1	%	6.1	%
Research and development tax credits	3.5	%	4.1	%	2.7	%
Orphan drug tax credits	2.9	%	2.3	%	4.6	%
Expiration of NOLs/Credits	(9.8)	%	(29.8)	%	(4.0)	%
Permanent adjustments and other	(0.2)	%	0.3	%	(0.6)	%
Stock based compensation	(9.4)	%	—	%	—	%
Change in valuation allowance	(14.2)	%	(4.0)	%	(29.8)	%
Effective income tax rate	—	%	—	%	—	%

Components of Deferred Tax Assets

The principal components of the Company’s deferred tax assets at December 31, 2021 and December 31, 2020, respectively, are as follows:

	December 31,
	2021		2020
Deferred Tax Assets:
NOL carryforwards	$	68,802	$	60,759
Research and development tax credit carryforwards	14,801		14,923
Orphan drug tax credit carryforwards	20,096		18,778
Depreciation and amortization	7,493		8,478
Capitalized research and development expenditures	37,528		34,832
Stock options	3,344		6,584
Accrued expenses and other	916		708
Oberland agreement	14,637		15,872
Lease liability ASC 842	1,371		1,846
Total gross deferred tax asset	168,988		162,780
Valuation allowance	(167,424)		(160,987)
Net deferred tax asset	$	1,564	$	1,793
Deferred tax liabilities:
Right of use asset ASC 842	(1,564)		(1,793)
Total gross deferred tax liabilities	$	(1,564)	$	(1,793)
Net deferred tax assets (liabilities)	$	—	$	—