Offer Letter by and between the Registrant and Gary Lee, dated November 24, 2021

I am very pleased to confirm our offer to you of employment with Lyell Immunopharma, Inc. (the “Company”). The opportunity to work with you to build one of the world’s great companies whose goal is nothing less than to develop curative therapies for solid tumors is one I am thrilled to have and know that your contributions will help ensure that we will achieve our ambitions.

1.Position. I am delighted to offer you a position as Chief Scientific Officer (CSO). Your proposed start date is January 31, 2022. You will be responsible for overseeing the research organization and will initially report to Elizabeth Homans, CEO. Your role is categorized as a Traveler and you will be authorized to be onsite up to 3 days per week depending on Company requirements. You will be based out of our South San Francisco, California office. The Company may change your position, duties, and work location from time to time in its discretion.

(a)Starting Salary. Your starting salary will be $480,000 per year, less payroll deductions and withholdings, paid on the Company’s normal payroll schedule. As a full- time exempt salaried employee, you will be expected to work the Company’s normal business hours as well as additional hours as required by the nature of your work assignments, and you will not be entitled to overtime compensation. Your salary will be subject to annual review and may or may not be adjusted in the Company’s sole discretion.

(b)Sign-on Bonus Advance. The Company will pay you a sign-on bonus

advance of $350,000, less applicable tax and other withholding within thirty (30) days after your start date (the “Sign-On Bonus Advance”). You will earn 50% of the Sign-On Bonus Advance if you remain continuously employed with the Company through the one year anniversary of your Start Date and you will earn the remaining 50% of the Sign-On Bonus Advance if you remain continuously employed with the Company through the second anniversary of your Start Date. If your employment with the Company terminates for any reason other than for Good Reason (as defined in the Officer Severance Benefit Plan) or without Cause, you authorize the Company to consider any unearned portion of the Sign-On Bonus Advance as a payroll advance and to deduct it from any amounts owed to you by the Company, including, without limitation, any accrued but unpaid salary and any unreimbursed business expenses. You agree to repay, within thirty (30) days of your last day of employment with the Company, any unearned portion of the Sign-On Bonus Advance previously paid to you by the Company in advance of becoming earned. If your employment terminates for Good Reason or based on a termination without Cause, the entire Sign- On Bonus Advance will be earned and will not need to be repaid by you. “Cause” as used herein,

(c)Target Annual Bonus. In addition, you will be eligible to earn an annual incentive bonus of up to 50 % of your base salary for the fiscal year of the Company (which runs from January 1st to December 31st) during which you commence employment, based on the achievement of performance objectives to be determined by the Company’s Board of Directors (the “Board”) or the Compensation Committee of the Board (the “Committee”) in the its sole discretion. Any bonus for the fiscal year in which your employment begins will be prorated, based on the number of days you are employed by the Company during that fiscal year. Thereafter, you will be eligible to receive an annual bonus in such amount and upon such terms as shall be determined by the Board or the Committee, in its sole discretion. If you remain on the same standard work hours and have a change to your base salary during the fiscal year, any bonus earned will be calculated based on your target bonus and base salary as of December 31 of that fiscal year. Any bonus for a fiscal year will be paid within 3 months after the close of that fiscal year, and you must be employed on the day that your bonus (if any) is paid in order to earn the bonus. Therefore, if your employment is terminated either by you or the Company for any reason prior to the bonus being paid, you will not have earned the bonus and no partial or prorated bonus will be paid. The determinations of the Board or the Committee with respect to your bonus will be final and binding.

3.Benefits. In addition, you will be eligible to participate in regular health insurance, bonus and other employee benefit plans established by the Company for its employees from time to time. The Company reserves the right to change or otherwise modify, in its sole discretion, the preceding terms of employment.

4.Equity. We will recommend to the Board of Directors of the Company that you be granted an option to purchase up to 800,000 shares of Common Stock of the Company (the “Option”). The Option will be granted under the Company’s 2021 Equity Incentive Plan, as amended (the “Plan”) and associated form of stock option agreement, and will have an exercise price equal to the fair market value of the Company’s Common Stock on the date such grant is approved by the Committee. The Option will be subject to the terms and conditions of the Plan and your grant agreement. The Option will vest at the rate of twenty five percent (25%) of the shares at the end of your first anniversary with the Company, and an additional 1/48th of the total shares subject to the Option per month thereafter, so long as you remain employed by the Company. However, the grant of such option by the Company is subject to the Committee’s approval and this promise to recommend such approval is not a promise of compensation and is not intended to create any obligation on the part of the Company. Further details on the Plan and any specific option grant to you will be provided upon approval of such grant by the Committee.

5.Severance Payments/COBRA. Your employment relationship with the Company is at will, as described below. You will be eligible to receive severance benefits as set forth in that certain Officer Severance Benefit Plan, while in effect and as amended from time to time by the Board or the Committee. You will be considered a Tier 1 employee under the Officer Severance Benefit Plan at all times during your Company employment.

6.Company Policies. You will be expected to abide by Company rules and policies (including but not limited to the Company’s Code of Business Conduct and Ethics, Insider Trading

7.Confidentiality. As an employee of the Company, you will have access to certain confidential information of the Company and you may, during the course of your employment, develop certain information or inventions that will be the property of the Company. To protect the interests of the Company, you will need to sign the Company’s standard “Employee Invention Assignment and Confidentiality Agreement” as a condition of your employment. We wish to impress upon you that we do not want you to, and we hereby direct you not to, bring with you any confidential or proprietary material of any former employer or to violate any other obligations you may have to any former employer. Rather, you will be expected to use only that information which is generally known and used by persons with training and experience comparable to your own, which is common knowledge in the industry or otherwise legally in the public domain, or which is otherwise provided or developed by the Company. You agree that you will not bring onto Company premises, or upload onto any Company systems, any unpublished documents, information or property belonging to any former employer or other person to whom you have an obligation of confidentiality.

8.No Breach of Obligations to Prior Employers. You represent that your signing of this offer letter, agreement(s) concerning stock options granted to you, if any, under the Plan (as defined above), and the Company’s Employee Invention Assignment and Confidentiality Agreement and your commencement of employment with the Company will not violate any agreement currently in place between yourself and current or past employers. You hereby represent that you have disclosed to the Company any contract you have signed that may restrict your activities on behalf of the Company.

9.Conflicting Obligations. During the period that you render services to the Company, you agree to not engage in any employment, business or activity that is in any way competitive with the business or proposed business of the Company. You will disclose to the Company in writing any other gainful employment, business or activity that you are currently associated with or participate in that competes with the Company. You will not assist any other person or organization in competing with the Company or in preparing to engage in competition with the business or proposed business of the Company.

10.At Will Employment. While we look forward to a long and profitable relationship, should you decide to accept our offer, you will be an at-will employee of the Company, which means the employment relationship can be terminated by either of us for any reason, at any time, with or without prior notice, and with or without cause. Any statements or representations to the contrary (and, indeed, any statements contradicting any provision in this letter) should be regarded by you as ineffective. Further, your participation in any stock option or benefit program is not to be regarded as assuring you of continuing employment for any particular period of time. Any modification or change in your at will employment status may only occur by way of a written employment agreement signed by you and the Chief Executive Officer of the Company.

11.Background Check. This offer is contingent upon satisfactory verification of criminal, education, driving and/or employment background and reference checks. This offer can be rescinded based upon data received in this verification.

12.Work Authorization. Please note that because of employer regulations adopted in the Immigration Reform and Control Act of 1986, within three (3) business days of starting your new position you will need to present documentation demonstrating that you have authorization to work in the United States.

13.COVID-19 Vaccination. This position requires you to work onsite at the Company’s facilities and the Company requires that all employees working in its facilities (including attending in-person meetings and events) be fully vaccinated against Covid-19 (except as required by applicable law). Therefore, this offer is contingent upon satisfactory proof that you are fully vaccinated from COVID-19, subject to reasonable accommodations for medical or religious reasons, and/or as otherwise required by applicable law. The Company considers you fully vaccinated once 14 days have passed since you received either the second dose in a two-dose COVID-19 vaccine series or a single-dose COVID-19 vaccine. Acceptance of this offer of employment is contingent on you maintaining a fully vaccinated status (including any vaccine boosters) against COVID-19 and providing vaccination attestation in our Human Resources Information System (UltiPro/UKG). The vaccine (including any vaccine booster) must have been FDA approved, have emergency use authorization from the FDA, or, for persons fully vaccinated outside of the U.S., be listed as approved by the World Health Organization or for emergency use by the World Health Organization.

14.Governing Law and Arbitration. This Agreement shall be governed by the law of the State of California. All questions concerning the construction, validity and interpretation of this Agreement will be governed by the laws of the State of California. To ensure the rapid and economical resolution of disputes that may arise in connection with your employment with the Company, you and the Company agree that any and all disputes, claims, or causes of action, in law or equity, including but not limited to statutory claims, arising from or relating to the enforcement, breach, performance, or interpretation of this letter Agreement, your employment with the Company, or the termination of your employment, shall be resolved pursuant to the Federal Arbitration Act, 9 U.S.C. § 1-16, to the fullest extent permitted by law, by final, binding and confidential arbitration conducted by JAMS or its successor, under JAMS’ then applicable rules and procedures for employment disputes before a single arbitrator (available upon request and also currently available at http://www.jamsadr.com/rules-employment-arbitration/). You acknowledge that by agreeing to this arbitration procedure, both you and the Company waive the right to resolve any such dispute through a trial by jury or judge or administrative proceeding. In addition, all claims, disputes, or causes of action under this section, whether by you or the Company, must be brought in an individual capacity, and shall not be brought as a plaintiff (or claimant) or class member in any purported class or representative proceeding, nor joined or consolidated with the claims of any other person or entity. The arbitrator may not consolidate the claims of more than one person or entity, and may not preside over any form of representative or class proceeding. To the extent that the preceding sentences regarding class claims or proceedings are found to violate applicable law or are otherwise found unenforceable, any claim(s) alleged or brought on behalf of a class shall proceed in a court of law rather than by arbitration. This paragraph shall not apply to any action or claim that cannot be subject to mandatory arbitration as a matter of law, including, without limitation, claims brought pursuant to the California Private Attorneys General Act of 2004, as amended, the California Fair Employment and Housing Act, as amended, and the California Labor Code, as amended, to the extent such claims are not permitted by applicable law(s) to be submitted to mandatory arbitration and the

applicable law(s) are not preempted by the Federal Arbitration Act or otherwise invalid (collectively, the “Excluded Claims”). In the event you intend to bring multiple claims, including one of the Excluded Claims listed above, the Excluded Claims may be filed with a court, while any other claims will remain subject to mandatory arbitration. You will have the right to be represented by legal counsel at any arbitration proceeding. Questions of whether a claim is subject to arbitration under this agreement shall be decided by the arbitrator. Likewise, procedural questions which grow out of the dispute and bear on the final disposition are also matters for the arbitrator. The arbitrator shall: (a) have the authority to compel adequate discovery for the resolution of the dispute and to award such relief as would otherwise be permitted by law; and (b) issue a written statement signed by the arbitrator regarding the disposition of each claim and the relief, if any, awarded as to each claim, the reasons for the award, and the arbitrator’s essential findings and conclusions on which the award is based. The arbitrator shall be authorized to award all relief that you or the Company would be entitled to seek in a court of law. The Company shall pay all JAMS arbitration fees in excess of the administrative fees that you would be required to pay if the dispute were decided in a court of law. Nothing in this letter agreement is intended to prevent either you or the Company from obtaining injunctive relief in court to prevent irreparable harm pending the conclusion of any such arbitration. Any awards or orders in such arbitrations may be entered and enforced as judgments in the federal and state courts of any competent jurisdiction.

15.Entire Agreement. This letter, together with your Employee Invention Assignment and Confidentiality Agreement, constitutes the entire agreement between you and the Company with respect to the subject matter hereof and supersedes all prior offers, negotiations and agreements, if any, whether written or oral, relating to such subject matter. Modifications or amendments to this agreement, other than those changes expressly reserved to the Company’s discretion in this letter, must be made in a written agreement signed by you and an officer of the Company. If any provision of this offer letter agreement is determined to be invalid or unenforceable, in whole or in part, this determination shall not affect any other provision of this offer letter agreement and the provision in question shall be modified so as to be rendered enforceable in a manner consistent with the intent of the parties insofar as possible under applicable law. You acknowledge that neither the Company nor its agents have made any promise, representation or warranty whatsoever, either express or implied, written or oral, which is not contained in this agreement for the purpose of inducing you to execute the agreement, and you acknowledge that you have executed this agreement in reliance only upon such promises, representations and warranties as are contained herein.

16.Acceptance. This offer will remain open until November 29, 2021. If you decide to accept our offer, and I hope you will, please sign the enclosed copy of this letter in the space indicated and return to the People team. We also ask that you sign and return to the People team the Employee Invention Assignment and Confidentiality Agreement that is enclosed. Your signature will acknowledge that you have read and understood and agreed to the terms and conditions of this offer letter and the attached documents, if any. Should you have anything else that you wish to discuss, please do not hesitate to call me.

I have read and understood this offer letter and hereby acknowledge, accept and agree to the terms as set forth above and further acknowledge that no other commitments were made to me as part of my employment offer except as specifically set forth herein.