Company: DAWN
Filing Date: 2025-03-06
Form Type: 10-K/A
Source: 0000950170-25-034878
Chunk: 54

Company: Day One Biopharmaceuticals, Inc.
Filing Date: 2025-03-06
Form: 10-K/A
Chunk 54
---
 based on tax positions related to prior year   |     |                         |     — |     |   |  (802 | ) |     |   |  (248 | ) |
| Reductions based on tax positions related to current year |     |                         |     — |     |   |     — |   |     |   |     — |   |
| Balance at end of year                                    |     | $                       | 6,372 |     | $ | 2,634 |   |     | $ | 2,535 |   |

The entire amount of the unrecognized tax benefits would not impact the Company’s effective tax rate if recognized. The Company has elected to include interest and penalties as a component of tax expense. During the years ended December 31, 2024, 2023 and 2022, the Company didnot recognize accrued interest and penalties related to unrecognized tax benefits. The Company does not anticipate that the amount of existing unrecognized tax benefits will significantly increase or decrease during the next12 months.

The Company files income tax returns in the U.S. federal, California and other state tax jurisdictions. The federal and state income tax returns from December 31, 2018 to December 31, 2023 remain subject to examination.

12. Defined Contribution Plan The Company maintains an employee savings plan pursuant to Section 401(k) of the Internal Revenue Code. All employees are eligible to participate provided that they meet the requirements of the plan. For the year ended December 31, 2024, 2023, and 2022, the Company made matching contributions of $ 1.7 million , $ 1.3 million, and $ 0.8 million, respectively.

13. Segment Reporting The Company views its operations and manages its business in one operating and one reportable segment, which includes all activities related to the identification, development and commercialization of medicines for childhood and adult diseases with equal intensity. The determination of a single operating segment is consistent with the consolidated financial information regularly provided to the Company’s chief operating decision maker, or

<div align='center'>F-34</div>

CODM.The Company’s CODM is its Chief Executive Officer, who reviews and evaluates net loss for purposes of assessing performance, making operating decisions, allocating resources, and planning and forecasting for future periods. Our CODM does not evaluate the operating segment using asset or liability information. The operating segment derives all net product revenues from the sales of OJEMDA in the United States through contractual arrangements with