Income Taxes

12 Months Ended

Dec. 31, 2023

Income Tax Disclosure [Abstract]

Income Taxes

Note 14. Income Taxes

Components of Income Before Taxes

For financial reporting purposes, income before income taxes includes the following components (in thousand):

	Year ended December 31,
	2023			2022			2021
Domestic	$	(149,540	)	$	(147,314	)	$	(101,878	)
Foreign		207			9			—
Income (loss) before income taxes	$	(149,333	)	$	(147,305	)	$	(101,878	)

Components of Tax Expense

There has historically been no federal, state or foreign provision for income taxes because the Company has historically incurred operating losses and maintains a full valuation allowance against its net deferred tax assets. For the years ended December 31, 2023, 2022 and 2021, the Company recognized no provision related to income taxes.

Effective Tax Rate

Reconciliation between the effective tax rate on income from continuing operations and the statutory tax rate of 21% is as follows:

	Year ended December 31,
	2023			2022			2021
U.S. federal provision at statutory rate		21.0	%		21.0	%		21.0	%
Tax credits		3.0	%		2.7	%		2.2	%
Stock-based compensation		(2.7	)%		1.9	%		3.9	%
Section 162(m)		(0.1	)%		(0.6	)%		(1.4	)%
Change in valuation allowance		(19.6	)%		(25.1	)%		(26.2	)%
Other		(1.6	)%		0.1	%		0.5	%
Effective tax rate		0.0	%		0.0	%		0.0	%

The Company’s effective tax rates differ from the federal statutory rate primarily due to the change in valuation allowance.

Deferred Taxes

The Company’s deferred income tax assets and liabilities as of December 31, 2023 and 2022 were as follows (in thousands):

	Year ended December 31,
	2023			2022
Deferred tax assets:
Net operating loss carry forward	$	62,346		$	59,613
Tax credits		18,261			11,473
Intangibles		3,499			3,718
Other		28			923
Stock-based compensation		1,998			2,759
Lease liability		1,542			1,912
Research and development costs		33,341			20,091
Accruals and reserves		1,364			1,190
Total deferred tax assets before valuation allowance		122,379			101,679
Valuation allowance		(120,779	)		(99,711	)
Total deferred tax assets		1,600			1,968
Deferred tax liabilities:		—			—
Right of use assets		(1,528	)		(1,899	)
Fixed assets		(72	)		(69	)
Total deferred tax liabilities		(1,600	)		(1,968	)
Net deferred tax assets (liabilities)	$	—		$	—

The Company assesses the realizability of deferred tax assets based on the available evidence, including a history of taxable income and estimates of future taxable income. In assessing the realizability of deferred tax assets, the Company considers whether it is more likely than not that all or some portion of deferred tax assets will not be realized. Due to the losses the Company generated in the current and prior years; the Company believes it is not more likely than not that all of the deferred tax assets can be realized. Accordingly, the Company established and recorded a full valuation allowance on its net deferred tax assets of $120.8 million as of December 31, 2023 and a net valuation allowance on its deferred tax assets of $99.7 million as of December 31, 2022. The valuation allowance increased by $21.1 million for the year ended December 31, 2023.

As of December 31, 2023, the Company had $232.2 million of U.S. federal and $189.9 million of state net operating loss carryforwards available to reduce future taxable income, of which $229.0 million will be carried forward indefinitely for U.S. federal tax purposes and the remainder of losses will expire beginning in 2036 for federal and 2031 for state tax purposes.

The Company also has federal and California research and development tax credit carryforwards of $21.2 million and $13.5 million, respectively. The federal research credit carryforwards will expire in 2036 and California research credits can be carried forward indefinitely.

The federal and state net operating loss carryforwards may be subject to significant limitations under Section 382 and Section 383 of the Internal Revenue Code of 1986, as amended, and similar provisions under state law. The Tax Reform Act of 1986 contains provisions that limit the federal net operating loss carryforwards that may be used in any given year in the event of special occurrences, including significant ownership changes. The Company has completed an analysis as of December 31, 2022 and doesn’t expect any net operating loss carryforwards or tax credit carryforwards to expire due to a limitation. The Company is in the process of preparing a Sec. 382 study through December 31, 2023.

Unrecognized Tax Benefits

The Company accrues for uncertain tax positions identified, which are not deemed more likely than not to be sustained if challenged, and recognizes interest and penalties accrued on any unrecognized tax benefits as a component of income tax expense. The Company has not accrued any interest on uncertain tax benefits associated with unrecognized tax benefits and had immaterial cumulative interest and penalties as of December 31, 2023, 2022 and 2021.

The Company does not expect that the total amounts of unrecognized tax benefits will significantly increase or decrease within 12 months of the reporting date.

The following is a tabular reconciliation of the total amounts of unrecognized tax benefits (in thousands):

	Year ended December 31,
	2023		2022			2021
Unrecognized tax benefits as of the beginning of the year	$	8,872	$	4,702		$	1,934
Increase related to prior year tax provisions		—		(100	)		107
Decrease related to prior year tax provisions		—		—			—
Increase related to current year tax provisions		4,937		4,270			2,661
Statue lapse		—		—			—
Unrecognized tax benefits as of the end of the year	$	13,809	$	8,872		$	4,702

Included in the balance of unrecognized tax benefits as of December 31, 2023, 2022 and 2021, are no amounts that, if recognized, would affect the effective tax rate.

The Company’s major tax jurisdictions are the United States, various states and India. Due to the net operating loss carryforward since inception, all tax years are open for examination. There have been no examinations of our income tax returns by any tax authority.