# EDGAR Filing Document

**Accession Number:** 0001580115
**File Stem:** 0001104659-25-073122
**Filing Date:** 2025-8
**Character Count:** 12476
**Document Hash:** 03acf7532256c6ababa44d2406db0822
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001104659-25-073122.hdr.sgml**: 20250801

**ACCESSION NUMBER**: 0001104659-25-073122

**CONFORMED SUBMISSION TYPE**: SCHEDULE 13G

**PUBLIC DOCUMENT COUNT**: 2

**FILED AS OF DATE**: 20250801

**DATE AS OF CHANGE**: 20250801

**SUBJECT COMPANY**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Lyell Immunopharma, Inc.
- **CENTRAL INDEX KEY:** 0001806952
- **STANDARD INDUSTRIAL CLASSIFICATION:** PHARMACEUTICAL PREPARATIONS [2834]
- **ORGANIZATION NAME:** 03 Life Sciences
- **EIN:** 833006753
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** SCHEDULE 13G
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 005-93402
- **FILM NUMBER:** 251176374

**BUSINESS ADDRESS:**
- **STREET 1:** 201 HASKINS WAY
- **CITY:** SOUTH SAN FRANCISCO
- **STATE:** CA
- **ZIP:** 94080
- **BUSINESS PHONE:** 650 695-0677

**MAIL ADDRESS:**
- **STREET 1:** 201 HASKINS WAY
- **CITY:** SOUTH SAN FRANCISCO
- **STATE:** CA
- **ZIP:** 94080
**FILED BY**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Gates Frontier, LLC
- **CENTRAL INDEX KEY:** 0001580115

**ORGANIZATION NAME:**
- **EIN:** 000000000
- **STATE OF INCORPORATION:** WA
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** SCHEDULE 13G

**BUSINESS ADDRESS:**
- **STREET 1:** 5210 CARILLON POINT
- **CITY:** KIRKLAND
- **STATE:** WA
- **ZIP:** 98033
- **BUSINESS PHONE:** 425-889-7900

**MAIL ADDRESS:**
- **STREET 1:** 5210 CARILLON POINT
- **CITY:** KIRKLAND
- **STATE:** WA
- **ZIP:** 98033

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** Gates Ventures, LLC
- **DATE OF NAME CHANGE:** 20130625

## Ex-1

**Exhibit 1**

**JOINT FILING AGREEMENT**

We, the signatories of the statement to which this Joint Filing Agreement is attached, hereby agree that such statement is filed, and any amendments thereto filed by any or all of us, will be filed, on behalf of each of us.

---

| | | | |
|:---|:---|:---|:---|
| Date: August 1, 2025 | GATES FRONTIER, LLC | GATES FRONTIER, LLC | GATES FRONTIER, LLC |
|  | By: | \* | \* |
|  |  | Name: | Alan Heuberger <sup>(1)</sup> |
|  |  | Title: | Attorney-in-fact for Michael Larson, Manager |
|  | <br> WILLIAM H. GATES III | <br> WILLIAM H. GATES III | <br> WILLIAM H. GATES III |
|  | By: | \* | \* |
|  |  | Name: | Alan Heuberger <sup>(2)</sup> |
|  |  | Title: | Attorney-in-fact |

---

---

| | |
|:---|:---|
| \*By: | /s/ Alan Heuberger |
|  | Alan Heuberger |

---

---

| | |
|:---|:---|
| <sup>(1</sup><sup>)</sup> | Duly authorized under Special Limited Power of Attorney appointing Alan Heuberger attorney-in-fact, dated October 11, 2013, by and on behalf of Michael Larson, filed as Exhibit 99.2 to Gates Frontier, LLC's Schedule 13G with respect to KiOR, Inc. on October 31, 2013, SEC File No. 005-86313, and incorporated by reference herein. |

---

---

| | |
|:---|:---|
| <sup>(2</sup><sup>)</sup> | Duly authorized under Special Limited Power of Attorney appointing Alan Heuberger attorney-in-fact, dated August 12, 2008, by and on behalf of William H. Gates III, filed as Exhibit 99.3 to Gates Frontier, LLC's Schedule 13G with respect to KiOR, Inc. on October 31, 2013, SEC File No. 005-86313, and incorporated by reference herein. |

---

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

## SCHEDULE 13G

### Under the Securities Exchange Act of 1934

**Issuer:** Lyell Immunopharma, Inc.

**Title of Class of Securities:** Common Stock, $0.0001 par value per share

**CUSIP Number:** 55083R203

**Date of Event Which Requires Filing of this Statement:** 07/25/2025

**Check the appropriate box to designate the rule pursuant to which this Schedule is filed:**

- [ ] Rule 13d-1(b)

- [x] Rule 13d-1(c)

- [ ] Rule 13d-1(d)

---

| 1. | Names of Reporting Persons<br>Gates Frontier, LLC | Names of Reporting Persons<br>Gates Frontier, LLC |
|:---|:---|:---|:---|
| 2. | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [ ] | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [ ] |
| 3. | SEC Use Only | SEC Use Only |
| 4. | Citizenship or Place of Organization<br>WA | Citizenship or Place of Organization<br>WA |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 5. | Sole Voting Power<br>1040964.00 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 6. | Shared Voting Power<br>0.00 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 7. | Sole Dispositive Power<br>1040964.00 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 8. | Shared Dispositive Power<br>0.00 |
| 9. | Aggregate Amount Beneficially Owned by Each Reporting Person<br>1040964.00 | Aggregate Amount Beneficially Owned by Each Reporting Person<br>1040964.00 |
| 10. | Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) [ ] | Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) [ ] |
| 11. | Percent of Class Represented by Amount in Row (9)<br>5.6% | Percent of Class Represented by Amount in Row (9)<br>5.6% |
| 12. | Type of Reporting Person (See Instructions)<br>OO | Type of Reporting Person (See Instructions)<br>OO |

**Comment for Type of Reporting Person:** For purposes of Rule 13d-3 under the Securities Exchange Act of 1934, as amended (the "Exchange Act"), all shares of the Common Stock, $0.0001 par value per share (the "Common Stock"), of Lyell Immunopharma, Inc. (the "Issuer") held by Gates Frontier, LLC ("Frontier") may be deemed to be beneficially owned by William H. Gates III as the sole member of Frontier.

Item 11 is based on 14,808,006 shares of Common Stock outstanding as of May 30, 2025, as reported on the Issuer's Form S-3 filed on July 18, 2025, plus 3,753,752 shares of Common Stock issued by the Issuer on July 25, 2025, as reported on the Issuer's Form 8-K filed on July 25, 2025.

---

| 1. | Names of Reporting Persons<br>William H. Gates III | Names of Reporting Persons<br>William H. Gates III |
|:---|:---|:---|:---|
| 2. | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [ ] | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [ ] |
| 3. | SEC Use Only | SEC Use Only |
| 4. | Citizenship or Place of Organization<br>X1 | Citizenship or Place of Organization<br>X1 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 5. | Sole Voting Power<br>1040964.00 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 6. | Shared Voting Power<br>0.00 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 7. | Sole Dispositive Power<br>1040964.00 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 8. | Shared Dispositive Power<br>0.00 |
| 9. | Aggregate Amount Beneficially Owned by Each Reporting Person<br>1040964.00 | Aggregate Amount Beneficially Owned by Each Reporting Person<br>1040964.00 |
| 10. | Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) [ ] | Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) [ ] |
| 11. | Percent of Class Represented by Amount in Row (9)<br>5.6% | Percent of Class Represented by Amount in Row (9)<br>5.6% |
| 12. | Type of Reporting Person (See Instructions)<br>IN | Type of Reporting Person (See Instructions)<br>IN |

**Comment for Type of Reporting Person:** For purposes of Rule 13d-3 under the Exchange Act, all shares of the Common Stock of the Issuer held by Frontier may be deemed to be beneficially owned by William H. Gates III as the sole member of Frontier.

Item 11 is based on 14,808,006 shares of Common Stock outstanding as of May 30, 2025, as reported on the Issuer's Form S-3 filed on July 18, 2025, plus 3,753,752 shares of Common Stock issued by the Issuer on July 25, 2025, as reported on the Issuer's Form 8-K filed on July 25, 2025.

---

**Item 1(a). Name of Issuer:**
Lyell Immunopharma, Inc.

**Item 1(b). Address of Issuer's Principal Executive Offices:**
201 Haskins Way South San Francisco, CA, 94080

**Item 2(a). Name of Person Filing:**
Gates Frontier, LLC ("Frontier") and William H. Gates III ("WHG")

**Item 2(b). Address of Principal Business Office:**
Frontier - 2365 Carillon Point, Kirkland, Washington 98033

WHG - 500 Fifth Avenue North, Seattle, Washington 98109

**Item 2(c). Citizenship:**
Frontier is a limited liability company organized under the laws of the State of Washington.

WHG is a citizen of the United States of America.

**Item 2(d). Title of Class of Securities:**
Common Stock, $0.0001 par value per share

**Item 2(e). CUSIP Number:**
55083R203

**Item 3. If this statement is filed pursuant to §§ 240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:**

(a) [ ] Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o).

(b) [ ] Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c).

(c) [ ] Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c).

(d) [ ] Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8).

(e) [ ] An investment adviser in accordance with § 240.13d-1(b)(1)(ii)(E);

(f) [ ] An employee benefit plan or endowment fund in accordance with § 240.13d-1(b)(1)(ii)(F);

(g) [ ] A parent holding company or control person in accordance with § 240.13d-1(b)(1)(ii)(G);

(h) [ ] A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);

(i) [ ] A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);

(j) [ ] A non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J), if filing as a non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J), please specify the type of institution:

(k) [ ] Group, in accordance with Rule 240.13d-1(b)(1)(ii)(K).

**Item 4. Ownership:**

**(a) Amount beneficially owned:**

See the responses to Item 9 on the attached cover pages.

**(b) Percent of class:**

See the responses to Item 11 on the attached cover pages.

**(c) Number of shares as to which the person has:**

**(i) Sole power to vote or to direct the vote:**

See the responses to Item 5 on the attached cover pages.

**(ii) Shared power to vote or to direct the vote:**

See the responses to Item 6 on the attached cover pages.

**(iii) Sole power to dispose or to direct the disposition of:**

See the responses to Item 7 on the attached cover pages.

**(iv) Shared power to dispose or to direct the disposition of:**

See the responses to Item 8 on the attached cover pages.

**Item 5. Ownership of Five Percent or Less of a Class.**

[x] If this statement is being filed to report the fact that as of the date hereof the reporting person has ceased to be the beneficial owner of more than five percent of the class of securities, check the following.

**Item 6. Ownership of More than 5 Percent on Behalf of Another Person.**

Not Applicable

**Item 7. Identification and Classification of the Subsidiary**

Not Applicable

**Item 8. Identification and Classification of Members of the Group**

Not Applicable

**Item 9. Notice of Dissolution of Group**

Not Applicable

**Item 10. Certification:**

By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under ?? 240.14a-11.

### SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

**Gates Frontier, LLC**

**Date:** 08/01/2025

**By:** /s/ Alan Heuberger

**Name & Title:** Attorney-in-fact for Michael Larson, Manager

**William H. Gates III**

**Date:** 08/01/2025

**By:** /s/ Alan Heuberger

**Name & Title:** Attorney-in-fact