Income Taxes - Schedule of Significant Components Deferred Tax Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Net operating loss carryforwards	$ 84,571	$ 84,827
Research and development credits	24,015	24,179
Deferred royalty obligation	36,687	36,265
Share-based compensation expense	2,742	2,497
Depreciation and amortization expense	482	1,044
Lease liability	80	136
Capital loss carryforward	126
Other	337	436
Total gross deferred tax assets	149,040	149,384
Right-of-use lease asset	(80)	(136)
Valuation allowance	$ (148,960)	$ (149,248)

Deferred Tax Asset, Deprecation And Amortization

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Deferred Tax Asset, Lease Liability

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Deferred tax assets capitalized research and development costs.

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Deferred Tax Liabilities, Right-Of-Use Lease Asset

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible capital loss carryforwards.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from in-process research and development costs expensed in connection with a business combination.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible operating loss carryforwards.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from share-based compensation.

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Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized.

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