Income Taxes (Tables)

12 Months Ended

Dec. 31, 2023

Income Tax Disclosure [Abstract]

Loss from Continuing Operations Before Provision for Income Taxes

Loss from continuing operations before provision for income taxes for the Company’s domestic and international operations was as follows (in thousands):

	Year Ended December 31,
	2023			2022			2021
United States	$	(10,377	)	$	(87,400	)	$	(80,926	)
Foreign		—			—			—
Loss before provision for income taxes	$	(10,377	)	$	(87,400	)	$	(80,926	)

Provision for Income Taxes

The provision for income taxes consists of the following (in thousands):

	Year Ended December 31,
	2023			2022			2021
Current
U.S. federal	$	—		$	—		$	—
U.S. state		1,555			—			—
Non-U.S.		—			—			—
Total current		1,555			—			—
Deferred
U.S. federal		(190	)		(5,606	)		(5,170	)
U.S. state		7,002			(4,334	)		(14,461	)
Non-U.S.		—			—			—
Total deferred		6,812			(9,940	)		(19,631	)
Valuation allowance		(6,806	)		9,940			19,631
Net deferred		6			—			—
Total	$	1,561		$	—		$	—

Components of Net Deferred Tax Assets

Components of the net deferred tax assets are approximately as follows (in thousands):

	December 31,
	2023			2022
Deferred tax assets:
Net operating loss carryforwards	$	506,641		$	542,537
Research and development credits		77,007			78,804
Capitalized research costs		14,225			4,369
Milestone Rights		1,006			1,331
Accrued expenses		3,760			2,675
Loss on purchase commitment		22,806			23,117
Non-qualified stock option expense		3,559			7,686
Capitalized patent costs		6,720			8,058
Other		3,405			3,204
Lease liability		1,280			1,624
Interest expense limitation		2,782			10,991
Depreciation		21,134			22,157
Deferred product revenue and costs		346			370
Sale of future royalties		34,848			-
Total deferred tax assets		699,519			706,923
Valuation allowance		(698,228	)		(705,034	)
Net deferred tax assets	$	1,291		$	1,889
Deferred tax liabilities:
Right of use asset	$	(1,121	)	$	(1,640	)
Other prepaids		(176	)		(249	)
Total deferred tax liabilities		(1,297	)		(1,889	)
Net deferred tax assets	$	(6	)	$	—

Effective Tax Rate

The Company’s effective tax rate differs from the statutory federal income tax rate as follows:

	Year Ended December 31,
	2023			2022			2021
Federal tax benefit rate		21.0	%		21.0	%		21.0	%
State tax expense (net of federal benefit)		-11.8	%		0.0	%		0.0	%
Permanent items		-2.8	%		-0.1	%		-4.4	%
Officers compensation		-35.3	%		-1.1	%		0.0	%
Stock based compensation		-5.6	%		0.4	%		0.3	%
Tax attribute expirations		0.4	%		-13.2	%		-5.9	%
Valuation allowance		9.1	%		-7.2	%		-11.2	%
Other deferred adjustments		10.0	%		0.2	%		0.2	%
Effective income tax rate		-15.0	%		0.0	%		0.0	%

Summary of Positions for which Significant Change in Unrecognized Tax Benefits

A reconciliation of beginning and ending amounts of unrecognized tax benefits was as follows (in thousands):

	Year Ended December 31,
	2023		2022		2021
Unrecognized Tax Benefit
Beginning of Year	$	268,902	$	268,902	$	268,902
Gross increases for tax positions of prior years		—		—		—
Gross decreases for tax positions of current year		—		—		—
Settlements		—		—		—
Lapse of statute of limitations		—		—		—
End of Year	$	268,902	$	268,902	$	268,902