INCOME TAXES (Tables)

12 Months Ended

Dec. 31, 2023

Income Tax Disclosure [Abstract]

Schedule reconciles the federal statutory tax rate to the effective income tax rate from continuing operations

The following table reconciles the federal statutory tax rate to the effective income tax rate from continuing operations:

	2023			2022				2021
Tax at statutory rate	21.0		%		21.0		%		21.0		%
State income tax, net of federal benefit	6.6				6.8				9.0
Federal and state tax credits	4.1				4.9				5.7
Stock-based compensation	(0.7	)			(0.8	)			(1.2	)
Net operating loss not benefitted	(5.7	)			(4.3	)			(5.4	)
Other	(0.5	)			(0.1	)			(0.2	)
Change in valuation allowance	(24.8	)			(27.5	)			(28.9	)
Effective tax rate	0.0		%		0.0		%		0.0		%

Schedule of significant components of the entity's deferred tax assets

Significant components of our deferred tax assets are as follows:

	December 31,
	2023			2022
	(In thousands)
Net operating loss carryforwards	$	272,300		$	254,500
Federal and state tax credits		64,700			56,700
Capitalized research and development		43,300			21,800
Stock-based compensation		11,200			10,800
Operating lease liabilities		1,100			1,300
Other		3,600			5,600
Total deferred tax assets		396,200			350,700
Less: valuation allowance		(395,200	)		(349,600	)
Net deferred tax assets		1,000			1,100
Operating leases, right-of-use assets		(1,000	)		(1,100	)
Total deferred tax liabilities		(1,000	)		(1,100	)
Total net deferred tax assets	$	—		$	—

Schedule of reconciliation of the beginning and ending amounts of unrecognized tax benefits

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

Balance as of December 31, 2022	$	23,700
Increase related to prior year tax positions		—
Increase related to current year tax positions		2,600
Balance as of December 31, 2023	$	26,300