14. Income Taxes

The Company derives its income only from the United States. The components of the provision for income taxes are as follows (in thousands):

The table reflects the ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures (ASU 2023-09). See “Note 2. Basis of Presentation and Summary of Significant Accounting Policies — Recent Accounting Pronouncements” for additional information on the adoption of ASU 2023-09.

The Company has established a valuation allowance against all of its net deferred tax assets. Management considered all available evidence, both positive and negative, including but not limited to our historical operating results, income or loss in recent periods, cumulative losses in recent years, forecasted earnings, future taxable income, and significant risk and uncertainty related to forecasts, and concluded the deferred tax assets are not more likely than not to be realized. The net change in the total valuation allowance for the years ended December 31, 2025 and 2024 was an increase of $25.2 million and a decrease of $13.4 million, respectively.

The Company had net operating loss carryforwards for federal and state income tax purposes of approximately $394.5 million and $56.9 million, respectively, as of December 31, 2025, available to reduce future taxable income. Of the federal net operating loss carryforwards, $65.6 million will begin to expire in 2034, if not utilized and $328.9 million will be carried forward indefinitely. The state net operating loss carryforwards will begin to expire in 2032, if not utilized.

The Company also has federal and state research and development tax credit carryforwards of $26.4 million and $15.0 million, respectively, as of December 31, 2025 available to reduce future income taxes. The federal research and development tax credits will begin to expire in 2031 if not utilized. The state research and development tax credits will carryforward indefinitely.

Internal Revenue Code section 382 (“IRC Section 382”) places a limitation (the “Section 382 Limitation”) on the amount of taxable income that can be offset by net operating loss (“NOL”) carryforwards after a change in control (generally greater than 50% change in ownership) of a loss corporation. California has similar rules. When such ownership change occurs, IRC Section 382 limits the use of NOLs and credits in subsequent periods based on the annual Section 382 Limitation. The Company performed an IRC Section 382 analysis and determined that there was no ownership change in 2025 which may result in a reduction of its NOLs or its research and development credits expiring unused.

Of the unrecognized tax benefits as of each of December 31, 2025 and 2024, approximately $2.3 million would affect the Company’s effective tax rate if recognized. Penalties and interest of $1.0 million and $1.0 million, respectively, have been accrued for as of December 31, 2025.

The Company files income taxes in the U.S. federal jurisdiction, the state of California and various other U.S. states. The state of California contested the Company’s tax position on revenue apportionment for upfront and milestone payments resulting from the Company’s collaboration and licensing agreements for the years 2017 and 2018. In September 2023, the Company received Notice of Proposed Assessment (“NOPA”) from the Franchise Tax Board. The Company recorded an uncertain tax position of $4.4 million in long term liabilities for the proposed tax assessment, penalties and interest through December 31, 2025. Additional utilization of carryforward attributes and indirect federal tax effects of the assessment would result in a reduction in deferred tax assets of $5.0 million. The Company filed a protest to contest the proposed assessment in November 2023. Due to the ongoing nature of the

examination and discussions with the state of California, the Company is unable to estimate a date by which this matter will be resolved.