X0508 4 2023-11-16 0 0001806952 Lyell Immunopharma, Inc. LYEL 0001866154 Hill Stephen J. C/O LYELL IMMUNOPHARMA, INC. 201 HASKINS WAY SOUTH SAN FRANCISCO CA 94080 0 1 0 0 Chief Technical Ops. Officer 0 Common Stock 8928 D Stock Option (right to buy) 1.87 2023-11-16 4 A 0 500000 A 2029-11-30 Common Stock 500000 500000 D Stock Option (right to buy) 3.65 2023-11-16 4 D 0 500000 D 2029-11-30 Common Stock 500000 0 D Stock Option (right to buy) 1.87 2023-11-16 4 A 0 165000 A 2030-01-15 Common Stock 165000 165000 D Stock Option (right to buy) 3.65 2023-11-16 4 D 0 165000 D 2030-01-15 Common Stock 165000 0 D Stock Option (right to buy) 1.87 2023-11-16 4 A 0 450000 A 2030-11-16 Common Stock 450000 450000 D Stock Option (right to buy) 5.96 2023-11-16 4 D 0 450000 D 2030-11-16 Common Stock 450000 0 D Stock Option (right to buy) 1.87 2023-11-16 4 A 0 100000 A 2031-02-11 Common Stock 100000 100000 D Stock Option (right to buy) 6.24 2023-11-16 4 D 0 100000 D 2031-02-11 Common Stock 100000 0 D Stock Option (right to buy) 1.87 2023-11-16 4 A 0 85000 A 2031-04-13 Common Stock 85000 85000 D Stock Option (right to buy) 12.67 2023-11-16 4 D 0 85000 D 2031-04-13 Common Stock 85000 0 D Stock Option (right to buy) 1.87 2023-11-16 4 A 0 700000 A 2032-03-15 Common Stock 700000 700000 D Stock Option (right to buy) 5.98 2023-11-16 4 D 0 700000 D 2032-03-15 Common Stock 700000 0 D Includes 2,941 shares acquired on May 18, 2022, 5,434 shares acquired on May 18, 2023 and 553 shares acquired on November 17, 2023 under the Issuer's 2021 Employee Stock Purchase Plan. Fully-vested. The transactions reported herein reflect a one-time stock option repricing (the "Option Repricing") effective on November 16, 2023 (the "Repricing Date"). The Option Repricing applies to options with exercise prices greater than $2.37 per share held by all continuing employees of the Issuer as of the Repricing Date. Pursuant to the Option Repricing, the exercise price of the repriced options, including the Option, has been amended to reduce the exercise price to $1.87 per share, the closing price of the Issuer's common stock on the Repricing Date. However, if an employee exercises a repriced option before the end of a retention period of one year (subject to earlier termination in certain circumstances), such employee will be required to pay the original exercise price per share of such repriced option. In addition, the vesting schedule for the unvested shares underlying repriced options held by executive officers, including the reporting person, was extended for an additional year. There is no change to the expiration dates of or number of shares underlying the repriced options. 154,688 shares were vested as of November 16, 2023 and the remaining unvested shares will vest in equal monthly installments over the following fifteen months based on the original vesting commencement date. 1/48th of the total shares vest in equal monthly installments over the forty-eight months following February 1, 2020. 328,125 shares were vested as of November 16, 2023 and the remaining unvested shares will vest in equal monthly installments over the following twenty-five months based on the original vesting commencement date. 1/48th of the total shares vest in equal monthly installments over the forty-eight months following December 1, 2020. 66,667 shares were vested as of November 16, 2023 and the remaining unvested shares will vest in equal monthly installments over the following twenty-eight months based on the original vesting commencement date. 1/48th of the total shares vest in equal monthly installments over the forty-eight months following March 1, 2021. 54,896 shares were vested as of November 16, 2023 and the remaining unvested shares will vest in equal monthly installments over the following twenty-nine months based on the original vesting commencement date. 1/48th of the total shares vest in equal monthly installments over the forty-eight months following April 14, 2021. 306,250 shares were vested as of November 16, 2023 and the remaining unvested shares will vest in equal monthly installments over the following thirty-nine months based on the original vesting commencement date. 12.5% of the option shares vested on August 9, 2022, with the remaining option shares to vest in equal monthly installments over the following forty-two months. /s/ Hector Casab, as Attorney-in-Fact 2023-11-20