UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 14A

Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934

(Amendment No. )

Filed by the Registrant			☒
Filed by a Party other than the Registrant			☐

Check the appropriate box:

☐			Preliminary Proxy Statement
☐			Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2))
☒			Definitive Proxy Statement
☐			Definitive Additional Materials
☐			Soliciting Material Pursuant to § 240.14a-12

LYELL IMMUNOPHARMA, INC.

(Name of Registrant as Specified In Its Charter)

(Name of Person(s) Filing Proxy Statement if other than the Registrant)

Payment of Filing Fee (Check all boxes that apply):

☒			No fee required.
☐			Fee paid previously with preliminary materials
☐			Fee computed on table in exhibit required by Item 25(b) per Exchange Act Rules 14a-6(i)(1) and 0-11

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LYELL IMMUNOPHARMA, INC.

201 Haskins Way

South San Francisco, CA 94080

NOTICE OF ANNUAL MEETING OF STOCKHOLDERS

To Be Held On June 14, 2024

Dear Stockholder:

You are cordially invited to attend the 2024 Annual Meeting of Stockholders (the “Annual Meeting”) of Lyell Immunopharma, Inc., a Delaware corporation (the “Company”). The Annual Meeting will be held on Friday, June 14, 2024 at 8:30 a.m. Pacific Time. To facilitate stockholder participation in the Annual Meeting, the Annual Meeting this year will be held virtually through a live webcast at www.virtualshareholdermeeting.com/LYEL2024. You will not be able to attend the Annual Meeting in person. The Annual Meeting will be held for the following purposes:

To elect the two (2) Class III director nominees named in the accompanying proxy statement (the “Proxy Statement”), to serve terms of three years through the third annual meeting of stockholders following this Annual Meeting and until, in each case, a successor has been elected and qualified, or until such director’s earlier death, resignation or removal.

2.	To ratify the appointment of Ernst & Young LLP as our independent registered public accounting firm for the fiscal year ending December 31, 2024.

3.	To approve, on an advisory basis, the compensation of the Company’s named executive officers, as disclosed in this Proxy Statement.

4.	To conduct any other business properly brought before the meeting.

These items of business are more fully described in the Proxy Statement accompanying this notice.

On or about April 22, 2024, we expect to mail to our stockholders a Notice of Internet Availability of Proxy Materials (the “Notice”) containing instructions on how to access our Proxy Statement and annual report. The Notice provides instructions on how to vote via the Internet or by telephone and how to receive a paper copy of our proxy materials.

You will be able to attend the Annual Meeting, submit questions and vote during the live webcast by visiting www.virtualshareholdermeeting.com/LYEL2024 and entering the 16-digit Control Number included in your Notice, voting instruction form, or in the instructions that you received via email. Please refer to the additional logistical details and recommendations in the Proxy Statement. You may log-in beginning at 8:15 a.m. Pacific Time on Friday, June 14, 2024.

The record date for the Annual Meeting is April 16, 2024. Only stockholders of record at the close of business on that date may vote at the meeting or any adjournment thereof.

By Order of the Board of Directors

Matthew Lang, J.D.

Chief Business Officer and Corporate Secretary

South San Francisco, California

April 22, 2024

You are cordially invited to attend the Annual Meeting online. Whether or not you expect to attend the meeting, please complete, date, sign and return the proxy mailed to you, the voting instruction form, or vote over the telephone or the internet as instructed in these materials, as promptly as possible to ensure your representation at the meeting. Even if you have voted by proxy, you may still vote your shares online at the Annual Meeting by clicking on the “Cast Your Vote” link in the meeting center.

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LYELL IMMUNOPHARMA, INC.

201 Haskins Way

South San Francisco, CA 94080

PROXY STATEMENT

FOR THE 2024 ANNUAL MEETING OF STOCKHOLDERS

June 14, 2024

MEETING AGENDA

Proposals	Page	Voting Standard for Approval	Board Recommendation
Election of Directors	8	Plurality of the votes of the shares present in person, by remote communication or represented by proxy at the Annual Meeting and entitled to vote in the election of directors. Only votes “For” will affect the outcome of the vote; “Withhold” votes will have no effect on the outcome of the vote; and under plurality voting, there are no abstentions.	“For” each named director nominee

Ratification of the appointment of Ernst & Young LLP as our independent registered public accounting firm for the fiscal year ending December 31, 2024	25	Majority of the voting power of the shares present in person, by remote communication or represented by proxy at the Annual Meeting and voting affirmatively or negatively (excluding abstentions and broker non-votes) on this matter.	“For”

Advisory vote to approve the compensation of the Company’s named executive officers	26	Majority of the voting power of the shares present in person, by remote communication or represented by proxy at the Annual Meeting and voting affirmatively or negatively (excluding abstentions and broker non-votes) on this matter.	“For”

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QUESTIONS AND ANSWERS ABOUT THESE PROXY MATERIALS AND VOTING			1
PROPOSAL 1 ELECTION OF DIRECTORS			8
Nominees to the Board of Directors			8
Continuing Directors			10
INFORMATION REGARDING THE BOARD OF DIRECTORS AND CORPORATE GOVERNANCE			12
Independence of the Board of Directors			12
Board Leadership Structure			12
Role of the Board in Risk Oversight			12
Meetings of The Board of Directors			13
Information Regarding Committees of the Board of Directors			13
Audit Committee			14
Report of the Audit Committee of the Board of Directors			16
Compensation Committee			17
Compensation Committee Processes and Procedures			17
Compensation Committee Interlocks and Insider Participation			18
Nominating and Corporate Governance Committee			19
Board Membership Criteria			20
Board Diversity			20
Stockholder Engagement and Communications with the Board Of Directors			21
Non-Employee Director Compensation			22
Code of Ethics			23
Corporate Governance Guidelines			23
Prohibitions on Hedging, Pledging and Short-Term Speculative Transactions			24
PROPOSAL 2 RATIFICATION OF APPOINTMENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM			25
PROPOSAL 3 ADVISORY VOTE TO APPROVE THE COMPENSATION OF OUR NAMED EXECUTIVE OFFICERS			26
EXECUTIVE OFFICERS			27
SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND MANAGEMENT			28
EXECUTIVE COMPENSATION			31
Compensation Discussion and Analysis			31
Compensation Committee Report			42
Summary Compensation Table			43
Grants of Plan-Based Awards			44
Outstanding Equity Awards at Fiscal Year End			45
Option Exercises and Stock Vested			46
Pension Benefits			46
Nonqualified Deferred Compensation			46
Employment Contracts and Change in Control Arrangements			46
Offer Letters			46
Officer Severance Plan			49
Potential Payments and Benefits Upon Termination or Change in Control			51
PAY VERSUS PERFORMANCE			53
CHIEF EXECUTIVE OFFICER PAY RATIO			57
EQUITY COMPENSATION PLANS AT DECEMBER 31, 2023			58
CERTAIN RELATIONSHIPS AND RELATED TRANSACTIONS			59
Related Person Transactions Policy and Procedures			59
Certain Related Person Transactions			59
SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS			60
HOUSEHOLDING OF PROXY MATERIALS			60
OTHER MATTERS			61

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QUESTIONS AND ANSWERS ABOUT THESE PROXY MATERIALS AND VOTING

Why did I receive a notice regarding the availability of proxy materials on the internet?

Pursuant to rules adopted by the Securities and Exchange Commission (the “SEC”), we have elected to provide access to our proxy materials over the internet. Accordingly, we have sent you a Notice of Internet Availability of Proxy Materials (the “Notice”) because the Board of Directors of Lyell Immunopharma, Inc. (sometimes referred to as the “Company” or “Lyell”) is soliciting your proxy to vote at the 2024 Annual Meeting of Stockholders (the “Annual Meeting”), including at any adjournments or postponements of the meeting. All stockholders will have the ability to access the proxy materials on the website referred to in the Notice or request to receive a printed set of the proxy materials. Instructions on how to access the proxy materials over the internet or to request a printed copy may be found in the Notice.

We intend to mail the Notice on or about April 22, 2024 to all stockholders of record entitled to vote at the Annual Meeting.

Will I receive any other proxy materials by mail?

No, you will not receive any other proxy materials by mail unless you request, or had previously requested, a paper copy of proxy materials. To request that a full set of the proxy materials be sent to your specified postal address for the Annual Meeting, you may (i) visit www.ProxyVote.com, (ii) call 1-800-579-1639 or (iii) send an email to sendmaterial@proxyvote.com. Please have your proxy card or Notice in hand when you access the website or call and follow the instructions provided and, if sending an email, please include your control number (discussed below) in the subject line.

How do I attend the Annual Meeting?

To facilitate stockholder participation in the Annual Meeting, the Annual Meeting this year will be held virtually through a live webcast at www.virtualshareholdermeeting.com/LYEL2024. You will not be able to attend the Annual Meeting in person. If you attend the Annual Meeting online, you will be able to vote and submit questions.

Who can attend the Annual Meeting?

You are entitled to attend the Annual Meeting if you were a stockholder as of the close of business on April 16, 2024, the record date. To be admitted to the Annual Meeting, you will need to visit www.virtualshareholdermeeting.com/LYEL2024 and enter the 16-digit Control Number found next to the label “Control Number” on your Notice of Internet Availability, proxy card or voting instruction form, or in the email sending you the Proxy Statement. If you are a beneficial stockholder, you should contact the bank, broker or other institution where you hold your account well in advance of the meeting if you have questions about obtaining your control number or proxy to vote.

Whether or not you participate in the Annual Meeting, it is important that you vote your shares.

We encourage you to access the Annual Meeting before it begins. Online check-in will start at 8:15 a.m. Pacific Time on Friday, June 14, 2024, approximately 15 minutes before the meeting begins.

What if I cannot find my Control Number?

Please note that if you do not have your Control Number, you will still be able to login and attend the Annual Meeting as a guest. To view the meeting webcast, visit www.virtualshareholdermeeting.com/LYEL2024 and register as a guest. If you log in as a guest, you will not be able to vote your shares or ask questions during the meeting.

Where can I get technical assistance?

If you have difficulty accessing the meeting, please call the number listed on the stockholder login page where technicians will be available to help you.

Will a list of record stockholders as of the record date be available?

A list of our record stockholders as of the close of business on the record date will be made available to stockholders during the Annual Meeting at www.virtualshareholdermeeting.com/LYEL2024.

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In addition, for the ten days prior to the Annual Meeting, the list will be available for examination by any stockholder of record for a legally valid purpose at our principal executive offices at the address listed above. Stockholders may also request to view a list of stockholders of record for the ten days prior to the Annual Meeting by sending an email to ir@lyell.com.

For the Annual Meeting, how do I ask questions of the Company?

We plan to have a Q&A session at the Annual Meeting and will include as many appropriate stockholder questions as the allotted time permits. Stockholders may submit questions that are relevant to our business during the meeting through www.virtualshareholdermeeting.com/LYEL2024.

Who can vote at the Annual Meeting?

Only stockholders of record at the close of business on April 16, 2024 will be entitled to vote at the Annual Meeting. On the record date, there were 254,936,784 shares of common stock outstanding and entitled to vote.

Stockholder of Record: Shares Registered in Your Name

If on April 16, 2024, your shares were registered directly in your name with Lyell’s transfer agent, American Stock Transfer & Trust Company, LLC, then you are a stockholder of record. As a stockholder of record, you may vote online at the Annual Meeting or vote by proxy over the telephone, vote by proxy through the internet or vote by proxy using a proxy card that you may request. Whether or not you plan to attend the Annual Meeting, we urge you to vote by proxy to ensure your vote is counted.

Beneficial Owner: Shares Registered in the Name of a Broker or Bank

If on April 16, 2024, your shares were held, not in your name, but rather in an account at a brokerage firm, bank or other similar organization, then you are the beneficial owner of shares held in “street name,” and this Notice is being forwarded to you by that organization. The organization holding your account is considered to be the stockholder of record for purposes of voting at the Annual Meeting. As a beneficial owner, you have the right to direct your broker, bank or other agent regarding how to vote the shares in your account. You are also invited to attend the Annual Meeting; however, since you are not the stockholder of record, you may not vote your shares online at the Annual Meeting unless you request and obtain a valid proxy from your broker or other agent. You may vote prior to the meeting by logging in with the Control Number on your voting instruction form at www.proxyvote.com. You may also access the Annual Meeting and vote during the meeting by logging in with your Control Number at www.virtualshareholdermeeting.com/LYEL2024.

What am I voting on?

There are three matters scheduled for a vote:

•	Election of two (2) Class III directors, each to serve a term of three years (Proposal 1);

•	Ratification of the appointment of Ernst & Young LLP as our independent registered public accounting firm for the fiscal year ending December 31, 2024 (Proposal 2); and

•	Advisory approval of the compensation of the Company’s named executive officers, as disclosed in this Proxy Statement in accordance with SEC rules (Proposal 3).

What if another matter is properly brought before the meeting?

The Board of Directors knows of no other matters that will be presented for consideration at the Annual Meeting. If any other matters are properly brought before the meeting, it is the intention of the persons named in the accompanying proxy to vote on those matters in accordance with their best judgment.

How do I vote?

For Proposal 1, you may either vote “For” all the nominees to the Board of Directors or you may “Withhold” your vote for any nominee you specify. For Proposal 2, ratification of the appointment of our independent registered public accounting firm, and Proposal 3, your advisory approval of the compensation of our named executive officers, you may vote “For” or “Against” or abstain from voting.

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The procedures for voting are as follows:

Stockholder of Record: Shares Registered in Your Name

If you are a stockholder of record, you may vote online at the Annual Meeting, vote by proxy over the telephone, vote by proxy through the internet or vote by proxy using a proxy card that you may request. Whether or not you plan to attend the Annual Meeting, we urge you to vote by proxy to ensure your vote is counted. You may still attend the Annual Meeting and vote at the meeting even if you have already voted by proxy.

•	To vote during the Annual Meeting, you must be present via live webcast and follow the instructions at www.virtualshareholdermeeting.com/LYEL2024. You will need to enter the 16-digit Control Number found on your Notice, proxy card or in the email sending you the Proxy Statement.

•	To vote prior to the Annual Meeting (until 11:59 p.m. Eastern Time on June 13, 2024), you may vote via the internet at www.proxyvote.com, by telephone or by completing and returning the proxy card, as described below.

•

To vote through the internet prior to the Annual Meeting, go to www.proxyvote.com and follow the instructions to submit your vote on an electronic proxy card. You will be asked to provide the company number and Control Number from the Notice, proxy card or email sending you the Proxy Statement. Your internet vote must be received by 11:59 p.m. Eastern Time on June 13, 2024 to be counted.

•

To vote over the telephone, dial the number provided on the Notice, proxy card or email sending you the Proxy Statement using a touch-tone phone and follow the recorded instructions. You will be asked to provide the company number and Control Number from your Notice, proxy card or email sending you the Proxy Statement. Your telephone vote must be received by 11:59 p.m. Eastern Time on June 13, 2024 to be counted.

•	To vote using the proxy card that may be requested, simply complete, sign and date the proxy card and return it promptly in the envelope provided. If you return your signed proxy card to us before the Annual Meeting, we will vote your shares as you direct.

Beneficial Owner: Shares Registered in the Name of Broker or Bank

If you are a beneficial owner of shares registered in the name of your broker, bank or other agent, you should have received a voting instruction form or Notice containing voting instructions from that organization rather than from us. To vote prior to the Annual Meeting, simply complete and mail the voting instruction form or follow the voting instructions in the Notice to ensure that your vote is counted. Alternatively, you may vote by telephone or over the internet as instructed by your broker or bank or by logging in with the Control Number on your voting instruction form at www.proxyvote.com. You may also access and vote at the Annual Meeting by logging in with your Control Number on your voting instruction form at www.virtualshareholdermeeting.com/LYEL2024.

Internet proxy voting will be provided to allow you to vote your shares online, with procedures designed to ensure the authenticity and correctness of your proxy vote instructions. However, please be aware that you must bear any costs associated with your internet access, such as usage charges from internet access providers and telephone companies.

How many votes do I have?

On each matter to be voted upon, you have one vote for each share of common stock you own as of April 16, 2024.

If I am a stockholder of record and I do not vote, or if I return a proxy card or otherwise vote without giving specific voting instructions, what happens?

If you are a stockholder of record and do not vote by completing your proxy card (if requested), by telephone, through the internet or online at the Annual Meeting, your shares will not be voted.

If you return a signed and dated proxy card or otherwise vote without marking voting selections, your shares will be voted, as applicable, “For” the election of both nominees for director (Proposal 1), “For” the ratification of the appointment of Ernst & Young LLP as our independent registered public accounting firm for the fiscal year ending

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December 31, 2024 (Proposal 2) and “For” the advisory approval of the compensation of our named executive officers (Proposal 3). If any other matter is properly presented at the meeting, your proxyholder (one of the individuals named on your proxy card) will vote your shares using his or her best judgment.

If I am a beneficial owner of shares held in street name and I do not provide my broker or bank with voting instructions, what happens?

If you are a beneficial owner of shares held in street name and you do not instruct your broker, bank or other agent how to vote your shares, your broker, bank or other agent may still be able to vote your shares in its discretion. Under the rules of the New York Stock Exchange (“NYSE”), brokers, banks and other securities intermediaries that are subject to NYSE rules may use their discretion to vote your “uninstructed” shares with respect to matters considered to be “routine” under NYSE rules, but not with respect to “non-routine” matters. All brokers registered as members with the NYSE are subject to NYSE rules and, accordingly, the NYSE rules apply to the voting of all shares held in a brokerage account, including shares of a company like ours listed on the Nasdaq Stock Market (“Nasdaq”). In this regard, Proposals 1 and 3 are considered to be “non-routine” under NYSE rules, meaning that your broker may not vote your shares on these proposals in the absence of your voting instructions. However, Proposal 2 is considered to be a “routine” matter under NYSE rules, meaning that if you do not return voting instructions to your broker by its deadline, your shares may be voted by your broker in its discretion on Proposal 2.

If you are a beneficial owner of shares held in street name, and you do not plan to attend the Annual Meeting, in order to ensure your shares are voted in the way you would prefer, you must provide voting instructions to your broker, bank or other agent by the deadline provided in the materials you receive from your broker, bank or other agent.

Who is paying for this proxy solicitation?

We will pay for the entire cost of soliciting proxies. In addition to these proxy materials, our directors and employees may also solicit proxies in person, by telephone or by other means of communication. Directors and employees will not be paid any additional compensation for soliciting proxies. We may also reimburse brokerage firms, banks and other agents for the cost of forwarding proxy materials to beneficial owners.

What does it mean if I receive more than one set of proxy materials or Notice?

If you receive more than one set of proxy materials or Notice, your shares may be registered in more than one name or in different accounts. Please follow the voting instructions in the proxy materials or Notices to ensure that all of your shares are voted.

Can I change my vote after submitting my proxy?

Stockholder of Record: Shares Registered in Your Name

Yes. You can revoke your proxy at any time before the final vote at the meeting. If you are the record holder of your shares, you may revoke your proxy in any one of the following ways:

•	You may request and submit another properly completed proxy card with a later date.

•	You may grant a subsequent proxy by telephone or through the internet.

•	You may send a timely written notice that you are revoking your proxy to our Corporate Secretary at 201 Haskins Way, South San Francisco, CA 94080.

•	You may attend the Annual Meeting and vote online. Simply attending the meeting will not, by itself, revoke your proxy.

Your most current proxy card or telephone or internet proxy is the one that is counted.

Beneficial Owner: Shares Registered in the Name of Broker or Bank

If your shares are held by your broker, bank or other agent, you should follow the instructions provided by your broker, bank or other agent.

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When are stockholder proposals due for next year’s annual meeting?

To be considered for inclusion in next year’s proxy materials, your proposal must be submitted in writing by December 23, 2024 to our Corporate Secretary at 201 Haskins Way, South San Francisco, CA 94080. However, if our 2025 Annual Meeting of Stockholders is not held between May 15, 2025 and July 14, 2025, then the deadline will be a reasonable time prior to the time that we begin to print and mail our proxy materials.

If you wish to submit a proposal (including a director nomination) at our 2025 Annual Meeting of Stockholders that is not to be included in next year’s proxy materials, you must do so by not earlier than February 14, 2025 and not later than 5:00 p.m. Pacific Time on March 16, 2025, provided, however, that if our 2025 Annual Meeting of Stockholders is not held between May 15, 2025 and July 14, 2025, your proposal must be submitted not earlier than the 120th day prior to our 2025 Annual Meeting of Stockholders and not later than the close of business on the 90th day prior to our 2025 Annual Meeting of Stockholders or the 10th day following the day on which public announcement of such meeting is first made. You are advised to review our bylaws, which contain additional requirements about advance notice of stockholder proposals and director nominations.

The proxy solicited by our Board of Directors for the 2025 Annual Meeting will confer discretionary voting authority with respect to (i) any proposal presented by a stockholder at that meeting for which we have not been provided with timely notice and (ii) any proposal made in accordance with our bylaws, even if the 2025 proxy statement briefly describes the matter and how management proxy holders intend to vote on it, if the stockholder does not comply with the requirements of Rule 14a-4(c)(2) promulgated under the Securities Exchange Act of 1934, as amended (“Exchange Act”).

How are votes counted?

Votes will be counted by the inspector of election appointed for the meeting, who will separately count, for Proposal 1 (proposal to elect directors), votes “For,” “Withhold” and broker non-votes; and with respect to Proposal 2 (proposal to ratify appointment of auditors) and Proposal 3 (stockholder advisory vote to approve the compensation of our named executive officers), votes “For” and “Against,” abstentions and, if applicable, broker non-votes. Abstentions and broker non-votes, if any, will have no effect and will not be counted towards the vote total for any proposal.

What are “broker non-votes”?

As discussed above, when a beneficial owner of shares held in street name does not give voting instructions to his or her broker, bank or other securities intermediary holding his or her shares as to how to vote on matters deemed to be “non-routine” under NYSE rules, the broker, bank or other such agent cannot vote the shares. These un-voted shares are counted as “broker non-votes.” Proposals 1 and 3 are considered to be “non-routine” under NYSE rules, and we therefore expect broker non-votes to exist in connection with these proposals.

As a reminder, if you are a beneficial owner of shares held in street name, in order to ensure your shares are voted in the way you would prefer, you must provide voting instructions to your broker, bank or other agent by the deadline provided in the materials you receive from your broker, bank or other agent.

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How many votes are needed to approve each proposal?

The following table summarizes the minimum vote needed to approve each proposal and the effect of abstentions and broker non-votes.

Election of Directors

Nominees receiving the most “For” votes; withheld votes will have no effect.

Not applicable

No effect

Ratification of the appointment of Ernst & Young LLP as our independent registered public accounting firm for the fiscal year ending December 31, 2024

“For” votes from the holders of a majority of the voting power of the shares present in person, by remote communication or represented by proxy at the meeting and voting affirmatively or negatively (excluding abstentions and broker non-votes) on the matter.

No effect

Not applicable⁽¹⁾

Advisory vote on the compensation of the Company’s named executive officers

No effect

(1)

This proposal is considered to be a “routine” matter under NYSE rules. Accordingly, if you hold your shares in street name and do not provide voting instructions to your broker, bank or other agent that holds your shares, your broker, bank or other agent has discretionary authority under NYSE rules to vote your shares on this proposal.

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What is the quorum requirement?

A quorum of stockholders is necessary to hold a valid meeting. A quorum will be present if stockholders holding at least a majority of the outstanding shares entitled to vote are present at the meeting by remote communication or represented by proxy. As noted above, on the record date, there were 254,936,784 shares of common stock outstanding and entitled to vote.

Your shares will be counted towards the quorum only if you submit a valid proxy (or one is submitted on your behalf by your broker, bank or other nominee) or if you vote online at the meeting. Abstentions and broker non-votes will be counted towards the quorum requirement. If there is no quorum, the holders of a majority of shares present at the meeting by remote communication or represented by proxy may adjourn the meeting to another date.

How can I find out the results of the voting at the Annual Meeting?

Preliminary voting results will be announced at the Annual Meeting. In addition, final voting results will be published in a current report on Form 8-K that we expect to file within four business days after the Annual Meeting. If final voting results are not available to us in time to file a Form 8-K within four business days after the meeting, we intend to file a Form 8-K to publish preliminary results and, within four business days after the final results are known to us, file an additional Form 8-K to publish the final results.

What proxy materials are available on the internet?

The Proxy Statement and Annual Report on Form 10-K are available at ir.lyell.com and www.proxyvote.com.

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Proposal 1

Election of Directors

Our Board of Directors is divided into three classes. Each class consists, as nearly as possible, of one-third of the total number of directors, and each class has a three-year term, the terms of office of the respective classes expiring in successive years. Vacancies on the Board of Directors may be filled by the affirmative vote of a majority of the directors then in office. A director elected by the Board of Directors to fill a vacancy in a class, including vacancies created by an increase in the number of directors, shall serve for the remainder of the full term of that class and until the director’s successor is duly elected and qualified.

The Board of Directors presently has eight members. There are two directors in Class III whose term of office expires in 2024. Drs. Nabel and Seely were elected as members of our Board of Directors prior to our initial public offering, and Dr. Nabel was elected pursuant to a voting agreement entered into with certain of our stockholders that terminated upon completion of our initial public offering in June 2021. Each of the nominees listed below is a current director who was nominated by the Board of Directors at the recommendation of the Nominating and Corporate Governance Committee. If elected at the Annual Meeting, each of these nominees would serve until the 2027 annual meeting and until her successor has been duly elected and qualified or, if sooner, until the director’s death, resignation or removal. It is our policy to encourage directors and nominees for director to attend the Annual Meeting. All directors attended our annual meeting of stockholders in 2023.

Directors are elected by a plurality of the votes of the holders of shares present in person, by remote communication or represented by proxy and entitled to vote on the election of directors. Accordingly, the two nominees receiving the highest number of affirmative votes will be elected. Shares represented by executed proxies will be voted, if authority to do so is not withheld, for the election of the two nominees named below. If any nominee becomes unavailable for election as a result of an unexpected occurrence, shares that would have been voted for that nominee will instead be voted for the election of a substitute nominee proposed by us. Each person nominated for election has agreed to serve if elected. Our management has no reason to believe that any nominee will be unable to serve.

Nominees to the Board of Directors

The nominees and their ages as of March 31, 2024, the class in which they are being nominated, positions and length of board service are provided in the table below. Additional biographical descriptions of each nominee are set forth in the text below the table. These descriptions include the primary individual experience, qualifications, qualities and skills of each of our nominees that led to the conclusion that each director should serve as a member of our Board of Directors at this time.

Elizabeth Nabel, M.D.⁽¹⁾⁽²⁾

III

Director

April 2021

Lynn Seely, M.D.

III

President, Chief Executive Officer and Director

May 2021

(1)	Member of the Audit Committee

(2)	Member of the Nominating and Corporate Governance Committee

Elizabeth Nabel, M.D., has served as a member of our board of directors since April 2021 and brings a unique perspective to health care based on her experience as a physician, research scientist, academic medicine leader and wellness advocate. She also serves on the board of directors of Moderna, Medtronic and Accolade. Dr. Nabel is the Chair of the Advisory Board of OPKO Health. Since March 2021, Dr. Nabel has served as Executive Vice President of Strategy of ModeX Therapeutics, a new biotechnology company focused on developing innovative immunotherapies for cancer and viral diseases. Following OPKO’s acquisition of ModeX, she served as Chief Medical Officer (part-time) of OPKO Health until June 2023. Through February 2021, Dr. Nabel was President of Brigham Health, which includes Brigham and Women’s Hospital, Brigham and Women’s Faulkner Hospital, and the Brigham and Women’s Physician Organization, a position she held from 2010. Simultaneous with her service as President of Brigham Health, Dr. Nabel was also a Professor of Medicine from 2010 to 2021 at Harvard Medical School, where she is currently a Professor of Medicine emeritus. Prior to joining Brigham Health, she held a variety of roles, including Director, at the National Heart, Lung and Blood Institute at the National Institutes of Health, a federal agency funding research, training and education programs to promote the prevention and treatment of heart,

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lung and blood diseases, from 1999 to 2009. Her colleagues have elected her to the American Academy of the Arts and Sciences, the National Academy of Medicine, the Association of American Physicians, the American Society of Clinical Investigation, and she is a Fellow of the American Association for the Advancement of Science. A native of St. Paul, Minnesota, Dr. Nabel received an M.D. from Weill Cornell Medical College and a B.A. in psychology from St. Olaf College, and she completed her internal medicine and cardiology training at Brigham and Women’s Hospital. We believe that Dr. Nabel’s education and work in medicine makes her an appropriate member of our Board of Directors.

Lynn Seely, M.D., has served as our President and Chief Executive Officer since December 2022 and has been a member of our board of directors since May 2021. She was formerly President and Chief Executive Officer and a member of the board of directors of Myovant Sciences, Inc., a biopharmaceutical company that gained marketing approval and launched ORGOVYX for men with advanced prostate cancer and MYFEMBREE for women with uterine fibroids and endometriosis. Prior to joining Myovant, Dr. Seely served as the Chief Medical Officer of Medivation, Inc. from 2005 to 2015. In this role, Dr. Seely oversaw the development and marketing approval of the blockbuster medicine XTANDI for men with castration-resistant prostate cancer and held leadership roles in drug development collaborations with Pfizer Inc. and Astellas Pharma US, Inc. Prior to joining Medivation, Dr. Seely served as Vice President of Clinical Development at Corgentech Inc., at Cytyc Health Corporation, and at ProDuct Health, Inc., a medical device company acquired by Cytyc Corporation. Dr. Seely began her industry career in clinical development at Chiron Corporation in 1996. In addition to serving on the Lyell Board, Dr. Seely serves as the lead independent director for Blueprint Medicines, is an independent director for TORL Biotherapeutics and is on the Board of Managers for Life Science Cares Bay Area. Dr. Seely received a B.A. in journalism from the University of Oklahoma and an M.D. from the University of Oklahoma College of Medicine. She completed her residency and served as Chief Resident in internal medicine at Yale-New Haven Hospital, and she completed her Fellowship in endocrinology and metabolism at the University of California, San Diego, where she was on faculty before joining industry. We believe that Dr. Seely’s education and work in healthcare and life sciences makes her an appropriate member of our Board of Directors.

Our Board Of Directors Recommends

A Vote “FOR” Each Named Nominee

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Continuing Directors

Continuing directors and their ages as of March 31, 2024, the class in which they belong, positions and length of board service are provided in the table below. Additional biographical descriptions of each director are set forth in the text below the table.

Hans Bishop⁽¹⁾

Director

August 2018

Otis Brawley, M.D.⁽²⁾

Director

April 2021

Catherine Friedman⁽³⁾⁽⁴⁾

Director

August 2018

Richard Klausner, M.D.

Chair of the Board of Directors

September 2018

Robert Nelsen⁽⁵⁾

Director

September 2018

William Rieflin⁽⁵⁾⁽⁶⁾

Director

May 2020

(1)	Member of the Nominating and Corporate Governance Committee

(2)	Chair of the Nominating and Corporate Governance Committee

(3)	Member of the Audit Committee

(4)	Chair of the Compensation Committee and Lead Independent Director

(5)	Member of the Compensation Committee

(6)	Chair of the Audit Committee

Hans Bishop has served as a member of our board of directors since August 2018. Since December 2021, Mr. Bishop has also served as the Board Co-Chair and President of Altos Labs, Inc., a private life sciences company. From July 2019 to September 2021, Mr. Bishop served as the Chief Executive Officer of GRAIL, a private life sciences company. From July 2013 to March 2018, Mr. Bishop served as President and Chief Executive Officer at Juno Therapeutics, a company that he co-founded and that was acquired by Celgene. From February 2012 through July 2013, Mr. Bishop served as Executive in Residence at Warburg Pincus, a multinational private equity firm. From January 2010 to September 2011, Mr. Bishop served as Executive Vice President and Chief Operating Officer at Dendreon, Inc., a publicly traded cancer immunotherapy company. From December 2006 to January 2010, Mr. Bishop served as President of Specialty Medicine at Bayer Healthcare, a publicly traded company. From January 2004 to August 2006, he served in multiple leadership positions at Chiron Corporation, a multinational biotechnology company, including as Senior Vice President of Global Commercial Operations and Vice President and General Manager of European Biopharmaceuticals. He currently serves as the Chairman of the Board of Sana Biotechnology and as a director of Agilent Technologies, both of which are publicly traded companies, and he previously served as a director of JW Therapeutics, Juno Therapeutics and Celgene. Mr. Bishop received a B.A. in Chemistry from Brunel University in London. We believe that Mr. Bishop’s more than 30 years of experience in the biotechnology industry and chemistry studies make him an appropriate member of our Board of Directors.

Otis Brawley, M.D., has served as a member of our board of directors since April 2021. Dr. Brawley has served as a Bloomberg Distinguished Professor of Oncology and Epidemiology at Johns Hopkins University since January 2019 and a member of the board of directors of PDS Biotechnology Corporation, a publicly traded biotechnology company, since November 2020, Incyte Corporation since September 2021 and Agilent Technologies since November 2021. From April 2007 to December 2018, he served as the Chief Medical and Scientific Officer of American Cancer Society. From January 2002 to August 2007, he was director of the Georgia Cancer Center at Grady Memorial Hospital. From April 2001 to December 2018, he served as a professor of hematology, oncology, medicine and epidemiology at Emory University. Dr. Brawley received an M.D. from the University of Chicago, Pritzker School of Medicine and a B.S. in Chemistry from the University of Chicago. He completed an internal medicine residency at Case-Western Reserve University and a fellowship in medical oncology at the National Cancer Institute. He is board certified in internal medicine and medical oncology. We believe that Dr. Brawley’s education and expertise in the field of oncology, as well as his experience on public company and non-profit boards, make him an appropriate member of our Board of Directors.

Catherine Friedman has served as a member of our board of directors since August 2018. Ms. Friedman is a business executive with nearly 40 years of experience across finance, technology and healthcare. Ms. Friedman is an Executive Venture Partner at GV Management Company, LLC, where she is a senior member of the investing team and advises the life sciences portfolio. Ms. Friedman has spent 15 years on the boards of leading public and private life sciences and technology companies. She has previously served as an independent director at Seer, Inc.,

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Altaba Inc. (formerly Yahoo!), Revolution Healthcare Acquisition Corp., GRAIL, Vividion Therapeutics (acquired by Bayer) and Radius Health. Earlier in her career, Ms. Friedman spent nearly 24 years with Morgan Stanley. She held several executive positions, including Managing Director, Head of West Coast Healthcare, and co-head of Morgan Stanley's biotechnology practice. Ms. Friedman holds a B.A. in economics from Harvard University and an M.B.A. from The University of Virginia's Darden School of Business. She is a foundation trustee at the University of Virginia's Darden School of Business. We believe that Ms. Friedman’s extensive financial experience and work for biotechnology companies make her an appropriate member of our Board of Directors.

Richard Klausner, M.D., is our founder and current Board Chair and was previously our Chief Executive Officer from September 2018 to July 2020 and Executive Chairman from August 2020 to October 2021. Dr. Klausner is the founder and Chief Scientist of Altos Labs, a private life sciences company. He is the President of the Milky Way Research Foundation and founder and Managing Partner of Milky Way Investments. He was the founder and Director of Juno Therapeutics and the founder and Director of GRAIL. He is the Board Chair of Sonoma Biotherapeutics and Co-Founder and Chairman of LifeMine Therapeutics. He is the former Senior Vice President, Chief Medical Officer, and Chief Opportunity Officer of Illumina Corporation. Previously, he was Executive Director for Global Health of the Bill and Melinda Gates Foundation. Dr. Klausner was appointed by Presidents Clinton and Bush as the eleventh Director of the U.S. National Cancer Institute between 1995 and 2001. Dr. Klausner served as chief of the Cell Biology and Metabolism Branch of the National Institute of Child Health and Human Development and a past president of the American Society of Clinical Investigation. He is a member of the National Academy of Sciences, the American Academy of Arts and Sciences, and the National Academy of Medicine. He has served in senior advisory roles to the U.S., Norwegian, Qatari, and Indian governments. Dr. Klausner earned an M.D. from Duke Medical School and a B.S. from Yale University. We believe that Dr. Klausner’s scientific and medical expertise, particularly in cell biology, molecular biology and cancer, as well as his industry, academic and public service leadership roles, make him an appropriate member of our Board of Directors.

Robert Nelsen has served as a member of our board of directors since September 2018. Since January 2022, Mr. Nelsen has also served as a member of the board of directors of Altos Labs, Inc., a private life sciences company. Since 1986, Mr. Nelsen has served as co-founder and Managing Director of ARCH Venture Partners, a venture capital firm focused on early-stage technology companies. Mr. Nelsen is a member of the board of directors of Brii Biosciences, Prime Medicine, Sana Biotechnology and Vir Biotechnology, all of which are publicly traded companies, and serves as Chairman of Hua Medicine. Previously, Mr. Nelsen served on the boards of several public biotechnology and biopharmaceutical companies, including Adolor Corporation, Agios Pharmaceuticals, Inc., Beam Therapeutics Inc., Bellerophon Therapeutics, Inc., Denali Therapeutics Inc., Fate Therapeutics, Inc., Gossamer Bio, Inc., Illumina, Juno Therapeutics, Karuna Therapeutics, Inc., Kythera Biopharmaceuticals, Inc., NeurogesX, Inc., Receptos, Inc., Revolution Healthcare Acquisition Corp., Sage Therapeutics, Inc., Sienna Biopharmaceuticals, Inc., Syros Pharmaceuticals, Inc. and Unity Biotechnology, Inc. Mr. Nelsen previously served as a trustee of the Fred Hutchinson Cancer Research Center and the Institute for Systems Biology and as a director of the National Venture Capital Association. Mr. Nelsen received an M.B.A. from the University of Chicago and a B.S. from the University of Puget Sound with majors in Economics and Biology. We believe that Mr. Nelsen’s extensive experience building and serving on the boards of many public and private emerging companies, including multiple life sciences, biotechnology and pharmaceutical companies, makes him an appropriate member of our Board of Directors.

William Rieflin has served as a member of our board of directors since May 2020. From September 2010 to September 2018, he served as the Chief Executive Officer of NGM Biopharmaceuticals, Inc. Since April 2015, Mr. Rieflin has served on the board of directors and has been Chairman of the Board since June 2019 at RAPT Therapeutics, Inc., a publicly traded biopharmaceutical company, and since July 2022, he has served as Chairman of the Board at NGM Biopharmaceuticals, Inc., a private biotechnology company. Mr. Rieflin also previously served as Executive Chairman since September 2018 and a member of the board since 2010 for NGM Biopharmaceuticals. Mr. Rieflin previously served on the board of directors of Anacor Pharmaceuticals, Inc., a pharmaceutical company, from April 2011 to June 2016 and of XenoPort, Inc. from September 2010 to July 2016. Mr. Rieflin also served as a board member of Flexus Biosciences until its acquisition in 2015. He currently serves on the board of directors of Kallyope, Inc. and Lycia Therapeutics, Inc., both privately held companies. Mr. Rieflin received an M.B.A. from the University of Chicago Booth Graduate School of Business, a J.D. from Stanford Law School and a B.S. in Industrial and Labor Relations from Cornell University. We believe that Mr. Rieflin’s extensive experience in the biopharmaceutical industry, his industry expertise and financial knowledge and his experience as a member of the board of directors of other public companies make him an appropriate member of our Board of Directors.

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INFORMATION REGARDING THE BOARD OF DIRECTORS AND CORPORATE GOVERNANCE

Independence of the Board of Directors

As required under the Nasdaq listing standards (the “Nasdaq Listing Rules”), a majority of the members of a listed company’s board of directors must qualify as “independent,” as affirmatively determined by the board of directors. Our Board of Directors consults with our counsel to ensure that their determinations are consistent with relevant securities and other laws and regulations regarding the definition of “independent,” including those set forth in pertinent Nasdaq Listing Rules, as in effect from time to time.

Consistent with these considerations, after review of all relevant identified transactions or relationships between each director, or any of his or her family members, and us, our senior management and our independent auditors, our Board of Directors has affirmatively determined that none of our directors, other than Drs. Klausner and Seely, has any relationship that would interfere with the exercise of independent judgment in carrying out the responsibilities of a director, and that each of these directors is “independent” as that term is defined under the Nasdaq Listing Rules. Our Board of Directors has determined that Drs. Klausner and Seely, by virtue of their positions as our Executive Chairman (until October 2021) and President and Chief Executive Officer, respectively, are not independent under applicable rules and regulations of the SEC and the Nasdaq Listing Rules. In making these determinations, our Board of Directors considered the current and prior relationships that each non-employee director has with us and all other facts and circumstances our Board of Directors deemed relevant in determining their independence, including the beneficial ownership of our shares by each non-employee director and the transactions described in the section titled “Certain Relationships and Related Transactions.”

Board Leadership Structure

Dr. Klausner currently serves as the Chair of the Board of Directors. In this role, Dr. Klausner has authority, among other things, to call and preside over Board of Directors meetings, to set meeting agendas and to determine materials to be distributed to the Board of Directors. Accordingly, the Chair has substantial ability to shape the work of the Board of Directors. While the positions of chief executive officer and chair are currently held by different individuals, we do not believe there should be a fixed rule regarding the separation of these positions, or whether the chair should be an employee of ours or should be elected from among the non-employee directors. Our needs and the individuals available to assume these roles may require different outcomes at different times, and we and our Board of Directors believe that retaining flexibility in these decisions is in our best interests. Our Nominating and Corporate Governance Committee periodically reviews these matters and makes recommendations to the Board of Directors.

Role of the Board in Risk Oversight

One of the key functions of the Board of Directors is informed oversight of our risk management process. Our Board of Directors does not have a standing risk management committee, but rather administers this oversight function directly through the Board of Directors as a whole, as well as through various standing committees of the Board of Directors that address risks inherent in their respective areas of oversight. In particular, our Board of Directors is responsible for monitoring and assessing strategic risk exposure, including a determination of the nature and level of risk appropriate for us.

Our Audit Committee has the responsibility to consider and discuss our major financial risk exposures and the steps our management team has taken to monitor and control these exposures, including guidelines and policies to govern the process by which risk assessment and management is undertaken. Our Audit Committee also monitors compliance with legal and regulatory requirements, in addition to oversight of the performance of our internal audit function. Audit Committee responsibilities also include oversight and monitoring of cybersecurity risk management, and, to that end, the committee regularly reviews and discusses with management risks relating to data privacy, technology and information security, including cybersecurity, and backup of information systems and the steps we have taken to monitor and control such exposures. Our Audit Committee receives regular reports from management about our cybersecurity risk management, as well as incidental reports as matters arise, and reports the same, as needed, to the full Board of Directors, which has overall responsibility to evaluate key business risks faced by us, including cybersecurity and information technology. We have based our cybersecurity assessment approach on the National Institute of Standards and Technology Cybersecurity Framework and are implementing methodologies that are consistent with that framework, such as asset management, leading protection and detection technologies, continual monitoring, employee training and business continuity plans. We arrange for independent security

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assessments to keep us up to date on new security gaps and measures we can implement. Additionally, we conduct random phishing and penetration tests to assess our defenses as well as our employees’ awareness of cybersecurity risks.

Our Nominating and Corporate Governance Committee monitors the effectiveness of our Corporate Governance Guidelines, including whether they are successful in preventing illegal or improper liability-creating conduct, as well as the effectiveness of our quality, corporate and healthcare compliance programs. Our Compensation Committee assesses and monitors whether any of our compensation policies and programs has the potential to encourage excessive risk-taking and/or are reasonably likely to have a material adverse effect on us. Quarterly, we provide to our Board of Directors updates on our enterprise risks. At least annually, we review and assess our risks as a whole and determine our most important enterprise risks. We then present to our Board of Directors the updated enterprise risks. Both the Board of Directors as a whole and the various standing committees receive periodic reports from the heads of our internal compliance and risk management functions, as well as incidental reports as matters may arise. It is the responsibility of the committee chairs to report findings regarding material risk exposures to the Board of Directors as quickly as possible.

Meetings of the Board of Directors

The Board of Directors met six times during the last fiscal year. All directors except Mr. Nelsen attended at least 75% of the aggregate number of meetings of the Board of Directors and of the committees on which they served, held during the portion of the last fiscal year for which they were directors or committee members, respectively. Mr. Nelsen was unable to attend several meetings of the Board of Directors and one meeting of the Compensation Committee because of scheduling conflicts.

Typically, in conjunction with the regularly scheduled meetings of the Board of Directors, the independent directors meet in executive sessions outside the presence of management. Additionally, Mr. Bishop and Dr. Klausner recuse themselves from participating in any discussions related to our T cell rejuvenation technology due to their affiliation with Altos Labs.

Information Regarding Committees of the Board of Directors

Our Board of Directors has three committees: an Audit Committee, a Compensation Committee and a Nominating and Corporate Governance Committee. Copies of the charters for each committee are available on the investor relations section of our website at https://ir.lyell.com.

The following table provides membership and meeting information for fiscal year 2023 for each of the committees of the Board of Directors:

SEC Form DEF 14A filed by Lyell Immunopharma Inc.