# EDGAR Filing Document

**Accession Number:** 0001845337
**File Stem:** 0001415889-25-019707
**Filing Date:** 2025-7
**Character Count:** 8396
**Document Hash:** d1c89ce5c58c10dc5915eeeeab0a131f
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001415889-25-019707.hdr.sgml**: 20250714

**ACCESSION NUMBER**: 0001415889-25-019707

**CONFORMED SUBMISSION TYPE**: 4

**PUBLIC DOCUMENT COUNT**: 1

**CONFORMED PERIOD OF REPORT**: 20250710

**FILED AS OF DATE**: 20250714

**DATE AS OF CHANGE**: 20250714

**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** Bender Jeremy
- **CENTRAL INDEX KEY:** 0001863107

**ORGANIZATION NAME:**

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-40431
- **FILM NUMBER:** 251121911

**MAIL ADDRESS:**
- **STREET 1:** 395 OYSTER POINT BLVD.
- **STREET 2:** SUITE 217
- **CITY:** SOUTH SAN FRANCISCO
- **STATE:** CA
- **ZIP:** 94080
**ISSUER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Day One Biopharmaceuticals, Inc.
- **CENTRAL INDEX KEY:** 0001845337
- **STANDARD INDUSTRIAL CLASSIFICATION:** PHARMACEUTICAL PREPARATIONS [2834]
- **ORGANIZATION NAME:** 03 Life Sciences
- **EIN:** 832415215
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**BUSINESS ADDRESS:**
- **STREET 1:** 2000 SIERRA POINT PARKWAY, SUITE 501
- **CITY:** BRISBANE
- **STATE:** CA
- **ZIP:** 94005
- **BUSINESS PHONE:** 650 484-0899

**MAIL ADDRESS:**
- **STREET 1:** 2000 SIERRA POINT PARKWAY, SUITE 501
- **CITY:** BRISBANE
- **STATE:** CA
- **ZIP:** 94005

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** Day One Biopharmaceuticals Holding Co LLC
- **DATE OF NAME CHANGE:** 20210209

### UNITED STATES SECURITIES AND EXCHANGE COMMISSION
**Washington, D.C. 20549**

## FORM 4

### STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

[ ] Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

[ ] Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

---

| | | |
|:---|:---|:---|
| **1. Name and Address of Reporting Person**<sup>*</sup><br>Bender Jeremy<br><sub>(Last) (First) (Middle)</sub><br>1800 SIERRA POINT PARKWAY, SUITE 200<br><sub>(Street)</sub><br>BRISBANE, CA 94005<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2025-07-10 | **5. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[X] Director [ ] 10% Owner<br>[X] Officer (give title below) [ ] Other (specify below)<br>_CHIEF EXECUTIVE OFFICER_ |
| **2. Issuer Name and Ticker or Trading Symbol**<br>Day One Biopharmaceuticals, Inc. [ DAWN ] | **4. If Amendment, Date of Original Filed (Month/Day/Year)**<br>  | **6. Individual or Joint/Group Filing (Check Applicable Line)**<br>[X] Form filed by One Reporting Person<br>[ ] Form filed by More than One Reporting Person |

---

## Table I - Non-Derivative Securities

---

|  |  |  |  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1. Title of Security | 2. Transaction Date | 2A. Deemed Execution Date | 3. Transaction Code (V) | 3. Transaction Code (V) | 4. Securities Acquired (A) or Disposed of (D) | 4. Securities Acquired (A) or Disposed of (D) | 4. Securities Acquired (A) or Disposed of (D) | 5. Amount of Securities Beneficially Owned | 6. Ownership Form | 7. Nature of Indirect Beneficial Ownership |
| 1. Title of Security | 2. Transaction Date | 2A. Deemed Execution Date | Code | V | Amount | (A) or (D) | Price | 5. Amount of Securities Beneficially Owned | 6. Ownership Form | 7. Nature of Indirect Beneficial Ownership |
| Common Stock | 2025-07-10 |  | G |  | 148312<sup>(1)</sup> | D | $0 | 14450 | I | See Footnote<sup>(2)</sup> |
| Common Stock | 2025-07-10 |  | G |  | 148312<sup>(1)</sup> | A | $0 | 955338 | I | By Bender Revocable Trust<sup>(3)</sup> |
| Common Stock | 2025-07-10 |  | G |  | 74328<sup>(4)</sup> | D | $0 | 147702 | I | See Footnote<sup>(5)</sup> |
| Common Stock | 2025-07-10 |  | G |  | 74328<sup>(4)</sup> | A | $0 | 1029666 | I | By Bender Revocable Trust<sup>(3)</sup> |
| Common Stock | 2025-07-10 |  | G |  | 199202<sup>(6)</sup> | D | $0 | 20204 | I | See Footnote<sup>(7)</sup> |
| Common Stock | 2024-07-02 |  | G |  | 199202<sup>(6)</sup> | A | $0 | 1228868 | I | By Bender Revocable Trust<sup>(3)</sup> |
| Common Stock | 2025-07-10 |  | G |  | 179417<sup>(8)</sup> | D | $0 | 18197 | I | See Footnote<sup>(9)</sup> |
| Common Stock | 2025-07-10 |  | G |  | 179417<sup>(8)</sup> | A | $0 | 1408285 | I | By Bender Revocable Trust<sup>(3)</sup> |
| Common Stock |  |  |  |  |  |  |  | 145737 | D |  |

---

## Table II - Derivative Securities

---

|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1. Title of Derivative Security | 2. Conversion or Exercise Price | 3. Transaction Date | 3A. Deemed Execution Date | 4. Transaction Code (V) | 4. Transaction Code (V) | 5. Number of Derivative Securities Acquired (A) or Disposed of (D) | 5. Number of Derivative Securities Acquired (A) or Disposed of (D) | 6. Date Exercisable and Expiration Date | 6. Date Exercisable and Expiration Date | 7. Title and Amount of Underlying Securities | 7. Title and Amount of Underlying Securities | 8. Price of Derivative Security | 9. Number of Derivative Securities Beneficially Owned | 10. Ownership Form | 11. Nature of Indirect Beneficial Ownership |
| 1. Title of Derivative Security | 2. Conversion or Exercise Price | 3. Transaction Date | 3A. Deemed Execution Date | Code | V | (A) | (D) | Date Exercisable | Expiration Date | Title | Amount or Number of Shares | 8. Price of Derivative Security | 9. Number of Derivative Securities Beneficially Owned | 10. Ownership Form | 11. Nature of Indirect Beneficial Ownership |
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |

---

### Footnotes:

(1) Represents an annuity payment made by The Jeremy Bender 2022 Grantor Retained Annuity Trust under Irrevocable Trust Agreement dated March 29, 2022 ("Jeremy Bender 2022 GRAT"), which was transferred by the Reporting Person as a bona fide gift for no consideration to the Bender Revocable Trust dated January 18, 2017, as amended, Jeremy Bender and Melissa C. Bender, Trustees ("Bender Revocable Trust dated January 18, 2017").

(2) Represents shares held by the Jeremy Bender 2022 GRAT of which the Reporting Person is trustee.

(3) Represents shares held by the Bender Revocable Trust dated January 18, 2017.

(4) Represents an annuity payment made by The Melissa Bender 2022 Grantor Retained Annuity Trust under Irrevocable Trust Agreement dated March 29, 2022 ("Melissa Bender 2022 GRAT"), which was transferred by the Reporting Person as a bona fide gift for no consideration to the Bender Revocable Trust dated January 18, 2017.

(5) Represents shares held by the Melissa Bender 2022 GRAT of which the Reporting Person's spouse is trustee.

(6) Represents an annuity payment made by The Jeremy Bender 2023 Grantor Retained Annuity Trust dated June 27, 2023 ("Jeremy Bender 2023 GRAT"), which was transferred by the Reporting Person as a bona fide gift for no consideration to the Bender Revocable Trust dated January 18, 2017.

(7) Represents shares held by the Jeremy Bender 2023 GRAT.

(8) Represents an annuity payment made by The Melissa Bender 2023 Grantor Retained Annuity Trust, dated June 27, 2023 ("Melissa Bender 2023 GRAT"), which was transferred by the Reporting Person as a bona fide gift for no consideration to the Bender Revocable Trust dated January 18, 2017.

(9) Represents shares held by the Melissa Bender 2023 GRAT.

**Signature:** /s/ Charles N. York II, Attorney-in-Fact  
**Date:** 2025-07-14

### Remarks:

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).

** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.

**Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.**