Lyell Immunopharma (LYEL): Foresite funds and Tananbaum report 2.7% ownership

Rhea-AI Filing Summary

Lyell Immunopharma, Inc. received an updated beneficial ownership report from Foresite Capital-affiliated funds and James B. Tananbaum. The group reports beneficial ownership of 653,328 shares of common stock, representing 2.7% of the class, based on 24,505,141 shares outstanding as of August 3, 2026. Foresite Capital Fund V, L.P. holds 476,386 shares (1.9%) and Foresite Capital Opportunity Fund V, L.P. holds 176,942 shares (0.7%). Foresite Capital Fund IV, L.P. and its related management entity report 0 shares. Voting and dispositive power over the fund-held shares may be deemed to reside with their respective general partners and ultimately with Tananbaum, who signs pursuant to an Agreement of Joint Filing.

Key Figures

Total beneficial ownership: 653,328 shares Ownership percentage: 2.7% Foresite Capital Fund V holding: 476,386 shares +3 more

6 metrics

Total beneficial ownership 653,328 shares Shares of Lyell Immunopharma common stock beneficially owned by Reporting Persons

Ownership percentage 2.7% Percentage of Lyell Immunopharma common stock beneficially owned by James B. Tananbaum

Foresite Capital Fund V holding 476,386 shares Lyell Immunopharma shares held by Foresite Capital Fund V, L.P. (1.9% of class)

Foresite Opportunity Fund V holding 176,942 shares Lyell Immunopharma shares held by Foresite Capital Opportunity Fund V, L.P. (0.7% of class)

Shares outstanding 24,505,141 shares Lyell Immunopharma common stock outstanding as of August 3, 2026

Foresite Fund IV holding 0 shares Lyell Immunopharma shares beneficially owned by Foresite Capital Fund IV, L.P.

Key Terms

beneficially owned, dispositive power, Agreement of Joint Filing, Investment Company Act of 1940

4 terms

beneficially owned financial

"Amount beneficially owned: See Row 9 of cover page for each Reporting Person."

Beneficially owned describes securities or assets where a person has the economic rights and control—such as the right to receive dividends and to direct voting—even if legal title is held in another name. Think of it like having the keys and using a car that’s registered to someone else: you get the benefits and make decisions. Investors care because beneficial ownership reveals who truly controls value and voting power, affecting corporate decisions and takeover dynamics.

dispositive power financial

"Sole Dispositive Power 476,386.00 8 | Shared Dispositive Power 0.00"

Dispositive power is the authority to decide the final outcome of an asset, legal claim, contract, or corporate action — in effect the power to dispose of or resolve something. For investors it matters because whoever holds that authority can determine who gets paid, who controls an asset or vote, and how risks and returns are allocated; think of it like holding the key that lets you lock in the winner or loser in a deal.

Agreement of Joint Filing regulatory

"Exhibit A Agreement of Joint Filing The undersigned hereby agree"

Investment Company Act of 1940 regulatory

"an investment company registered under the Investment Company Act of 1940"

A U.S. federal law that sets the rulebook for pooled investment vehicles such as mutual funds, exchange-traded funds and similar money managers, requiring them to register with regulators, disclose holdings and fees, limit conflicts of interest, and follow governance standards. It matters to investors because these protections and transparency rules act like a referee and scoreboard, helping people compare funds, trust that managers follow fair practices, and spot hidden costs or risks.

FAQ

What ownership in Lyell Immunopharma (LYEL) do the Foresite funds report?

The Foresite Capital-affiliated funds report beneficial ownership of 653,328 Lyell Immunopharma shares in total, representing 2.7% of the common stock. This includes 476,386 shares held by Foresite Capital Fund V and 176,942 shares held by Foresite Capital Opportunity Fund V.

How much of Lyell Immunopharma (LYEL) does James B. Tananbaum beneficially own?

James B. Tananbaum may be deemed to beneficially own 653,328 shares of Lyell Immunopharma common stock, or 2.7% of the outstanding shares. These shares are held through Foresite Capital Fund V and Foresite Capital Opportunity Fund V, over which entities he has managing roles.

What percentage of Lyell Immunopharma (LYEL) does each Foresite fund hold?

Foresite Capital Fund V, L.P. holds 476,386 shares, equal to 1.9% of Lyell’s common stock. Foresite Capital Opportunity Fund V, L.P. holds 176,942 shares, equal to 0.7%. Foresite Capital Fund IV, L.P. and its manager report 0% ownership.

What share count did Lyell Immunopharma (LYEL) use to calculate these ownership percentages?

All reported ownership percentages are calculated using 24,505,141 shares of Lyell Immunopharma common stock outstanding as of August 3, 2026, as referenced in the company’s Quarterly Report on Form 10-Q filed on August 6, 2026.

Do the Foresite entities share voting or dispositive power over Lyell (LYEL) shares?

The filing states that relevant Foresite management LLCs and James B. Tananbaum may be deemed to have sole voting and dispositive power over the shares held by the limited partnerships. No shared voting or dispositive power is reported for any Reporting Person.

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Available on EDGAR 08/14/2026 - 04:27 PM Accepted by SEC EDGAR 08/14/2026 - 04:03 PM Learn about SEC filing dates

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No. 4)

Lyell Immunopharma, Inc.

(Name of Issuer)

Common Stock, par value $0.0001

(Title of Class of Securities)

55083R203

(CUSIP Number)

06/30/2026

(Date of Event Which Requires Filing of this Statement)

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

Rule 13d-1(b)

Rule 13d-1(c)

Rule 13d-1(d)

schemaVersion:

SCHEDULE 13G

CUSIP Number(s): 55083R203

1

Names of Reporting Persons

Foresite Capital Fund IV, L.P.

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 0.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 0.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

0.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

0.0 %

12

Type of Reporting Person (See Instructions)

PN

SCHEDULE 13G

CUSIP Number(s): 55083R203

1

Names of Reporting Persons

Foresite Capital Management IV, LLC

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 0.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 0.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

0.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

0.0 %

12

Type of Reporting Person (See Instructions)

OO

SCHEDULE 13G

CUSIP Number(s): 55083R203

1

Names of Reporting Persons

Foresite Capital Fund V, L.P.

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 476,386.00
6	Shared Voting Power 0.00
7	Sole Dispositive Power 476,386.00
8	Shared Dispositive Power 0.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

476,386.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

1.9 %

12

Type of Reporting Person (See Instructions)

PN

Comment for Type of Reporting Person: Note to Row 5: 476,386 shares, except that Foresite Capital Management V, LLC ("FCM V"), the general partner of Foresite Capital Fund V, L.P. ("FCF V"), may be deemed to have sole power to vote these shares, and James B. Tananbaum ("Tananbaum"), the managing member of FCM V, may be deemed to have sole power to vote these shares. Note to Row 6: See response to Row 5. Note to Row 7: 476,386 shares, except that FCM V, the general partner of FCF V, may be deemed to have sole power to dispose of these shares, and Tananbaum, the managing member of FCM V, may be deemed to have sole power to dispose of these shares. Note to Row 8: See response to Row 7. Note to Row 11: This percentage is calculated based upon 24,505,141 shares of Common Stock outstanding of the Lyell Immunopharma, Inc. (the "Issuer") as of August 3, 2026, as set forth in the Issuer's Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission on August 6, 2026.

SCHEDULE 13G

CUSIP Number(s): 55083R203

1

Names of Reporting Persons

Foresite Capital Management V, LLC

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 476,386.00
6	Shared Voting Power 0.00
7	Sole Dispositive Power 476,386.00
8	Shared Dispositive Power 0.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

476,386.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

1.9 %

12

Type of Reporting Person (See Instructions)

OO

Comment for Type of Reporting Person: Note to Row 5: 476,386 shares, all of which are directly owned by FCF V. FCM V, the general partner of FCF V, may be deemed to have sole power to vote these shares, and Tananbaum, the managing member of FCM V, may be deemed to have sole power to vote these shares. Note to Row 6: See response to Row 5. Note to Row 7: 476,386 shares, all of which are directly owned by FCF V. FCM V, the general partner of FCF V, may be deemed to have sole power to dispose of these shares, and Tananbaum, the managing member of FCM V, may be deemed to have sole power to dispose of these shares. Note to Row 8: See response to Row 7. Note to Row 11: This percentage is calculated based upon 24,505,141 shares of Common Stock outstanding of the Issuer as of August 3, 2026, as set forth in the Issuer's Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission on August 6, 2026.

SCHEDULE 13G

CUSIP Number(s): 55083R203

1

Names of Reporting Persons

Foresite Capital Opportunity Fund V, L.P.

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 176,942.00
6	Shared Voting Power 0.00
7	Sole Dispositive Power 176,942.00
8	Shared Dispositive Power 0.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

176,942.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

0.7 %

12

Type of Reporting Person (See Instructions)

PN

Comment for Type of Reporting Person: Note to Row 5: 176,942 shares, except that Foresite Capital Opportunity Management V, LLC ("FCM Opp V"), the general partner of Foresite Capital Opportunity Fund V, L.P. ("FCF Opp V"), may be deemed to have sole power to vote these shares, and Tananbaum, the managing member of FCM Opp V, may be deemed to have sole power to vote these shares. Note to Row 6: See response to Row 5. Note to Row 7: 176,942 shares, except that FCM Opp V, the general partner of FCF Opp V, may be deemed to have sole power to dispose of these shares, and Tananbaum, the managing member of FCM Opp V, may be deemed to have sole power to dispose of these shares. Note to Row 8: See response to Row 7. Note to Row 11: This percentage is calculated based upon 24,505,141 shares of Common Stock outstanding of the Issuer as of August 3, 2026, as set forth in the Issuer's Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission on August 6, 2026.

SCHEDULE 13G

CUSIP Number(s): 55083R203

1

Names of Reporting Persons

Foresite Capital Opportunity Management V, LLC

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 176,942.00
6	Shared Voting Power 0.00
7	Sole Dispositive Power 176,942.00
8	Shared Dispositive Power 0.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

176,942.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

0.7 %

12

Type of Reporting Person (See Instructions)

OO

Comment for Type of Reporting Person: Note to Row 5: 176,942 shares, all of which are directly owned by FCF Opp V. FCM Opp V, the general partner of FCF Opp V, may be deemed to have sole power to vote these shares, and Tananbaum, the managing member of FCM Opp V, may be deemed to have sole power to vote these shares. Note to Row 6: See response to Row 5. Note to Row 7: 176,942 shares, all of which are directly owned by FCF Opp V. FCM Opp V, the general partner of FCF Opp V, may be deemed to have sole power to dispose of these shares, and Tananbaum, the managing member of FCM Opp V, may be deemed to have sole power to dispose of these shares. Note to Row 8: See response to Row 7. Note to Row 11: This percentage is calculated based upon 24,505,141 shares of Common Stock outstanding of the Issuer as of August 3, 2026, as set forth in the Issuer's Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission on August 6, 2026.

SCHEDULE 13G

CUSIP Number(s): 55083R203

1

Names of Reporting Persons

James B. Tananbaum

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

UNITED STATES

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 653,328.00
6	Shared Voting Power 0.00
7	Sole Dispositive Power 653,328.00
8	Shared Dispositive Power 0.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

653,328.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

2.7 %

12

Type of Reporting Person (See Instructions)

IN

Comment for Type of Reporting Person: Note to Row 5: 653,328 shares, of which 0 shares are directly owned by Foresite Capital Fund IV, L.P. ("FCF IV"), 476,386 shares are directly owned by FCF V and 176,942 shares are directly owned by FCF Opp V. Tananbaum is the managing member of each of Foresite Capital Management IV, LLC ("FCM IV"), which is the general partner of FCF IV, FCM V, which is the general partner of FCF V and FCM Opp V, which is the general partner of FCF Opp V. Tananbaum may be deemed to have sole power to vote these shares. Note to Row 6: See response to Row 5. Note to Row 7: 653,328 shares, of which 0 shares are directly owned by FCF IV, 476,386 shares are directly owned by FCF V and 176,942 shares are directly owned by FCF Opp V. Tananbaum is the managing member of each of FCM IV, which is the general partner of FCF IV, FCM V, which is the general partner of FCF V and FCM Opp V, which is the general partner of FCF Opp V. Tananbaum may be deemed to have sole power to dispose of these shares. Note to Row 8: See response to Row 7. Note to Row 11: This percentage is calculated based upon 24,505,141 shares of Common Stock outstanding of the Issuer as of August 3, 2026, as set forth in the Issuer's Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission on August 6, 2026.

SCHEDULE 13G

Item 1.
(a)	Name of issuer: Lyell Immunopharma, Inc.
(b)	Address of issuer's principal executive offices: 201 Haskins Way South San Francisco, CA 94080
Item 2.
(a)	Name of person filing: This Schedule is filed by Foresite Capital Fund IV, L.P., a Delaware limited partnership, Foresite Capital Management IV, LLC, a Delaware limited liability company, Foresite Capital Fund V, L.P., a Delaware limited partnership, Foresite Capital Management V, LLC, a Delaware limited liability company, Foresite Capital Opportunity Fund V, L.P., a Delaware limited partnership, Foresite Capital Opportunity Management V, LLC, a Delaware limited liability company, and James B. Tananbaum. The foregoing entities and individuals are collectively referred to as the "Reporting Persons."
(b)	Address or principal business office or, if none, residence: c/o Foresite Capital Management 9200 Sunset Boulevard, Suite PH1 West Hollywood, CA 90069
(c)	Citizenship: See Row 4 of cover page for each Reporting Person.
(d)	Title of class of securities: Common Stock, par value $0.0001
(e)	CUSIP No.: 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 Row 9 of cover page for each Reporting Person.
(b)	Percent of class: See Row 11 of cover page for each Reporting Person.
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: See Row 5 of cover page for each Reporting Person.
	(ii) Shared power to vote or to direct the vote: See Row 6 of cover page for each Reporting Person.
	(iii) Sole power to dispose or to direct the disposition of: See Row 7 of cover page for each Reporting Person.
	(iv) Shared power to dispose or to direct the disposition of: See Row 8 of cover page for each Reporting Person.
Item 5.	Ownership of 5 Percent or Less of a Class.
	Ownership of 5 percent or less of a class
Item 6.	Ownership of more than 5 Percent on Behalf of Another Person.
	If any other person is known to have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, such securities, a statement to that effect should be included in response to this item and, if such interest relates to more than 5 percent of the class, such person should be identified. A listing of the shareholders of an investment company registered under the Investment Company Act of 1940 or the beneficiaries of employee benefit plan, pension fund or endowment fund is not required. Under certain circumstances set forth in the limited partnership agreements of FCF IV, FCF V, and FCF Opp V and the limited liability company agreements of FCM IV, FCM V, and FCM Opp V, the partners or members, as the case may be, of each of such entities may be deemed to have the right to receive dividends from, or the proceeds from the sale of, shares of the Issuer directly or indirectly owned by each such entity of which they are a partner or member.
Item 7.	Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person.
	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.

Certifications:

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.

Foresite Capital Fund IV, L.P.

Signature:	/s/ James B. Tananbaum
Name/Title:	James B. Tananbaum, Managing Member of the General Partner
Date:	08/14/2026

Foresite Capital Management IV, LLC

Signature:	/s/ James B. Tananbaum
Name/Title:	James B. Tananbaum, Managing Member
Date:	08/14/2026

Foresite Capital Fund V, L.P.

Signature:	/s/ James B. Tananbaum
Name/Title:	James B. Tananbaum, Managing Member of the General Partner
Date:	08/14/2026

Foresite Capital Management V, LLC

Signature:	/s/ James B. Tananbaum
Name/Title:	James B. Tananbaum, Managing Member
Date:	08/14/2026

Foresite Capital Opportunity Fund V, L.P.

Signature:	/s/ James B. Tananbaum
Name/Title:	James B. Tananbaum, Managing Member of the General Partner
Date:	08/14/2026

Foresite Capital Opportunity Management V, LLC

Signature:	/s/ James B. Tananbaum
Name/Title:	James B. Tananbaum, Managing Member
Date:	08/14/2026

James B. Tananbaum

Signature:	/s/ James B. Tananbaum
Name/Title:	James B. Tananbaum
Date:	08/14/2026

Exhibit Information

Exhibit A Agreement of Joint Filing The undersigned hereby agree that a single Schedule 13G (or any amendment thereto) relating to the Common Stock of the Issuer shall be filed on behalf of each of the undersigned. Note that a copy of the applicable Agreement of Joint Filing is already on file with the appropriate agencies.