X0609 4 2026-09-10 0001806952 Lyell Immunopharma, Inc. LYEL 0002150331 Aguirre Jarrad Mattieu false C/O LYELL IMMUNOPHARMA, INC. 201 HASKINS WAY SOUTH SAN FRANCISCO CA 94080 false true false false Chief Medical Officer 0 Common Stock 20279 D Option (right to buy) 12.20 2026-09-10 4 A 0 47500 0 A 2036-09-09 Common Stock 47500 47500 D Includes 14,451 restricted stock units ("RSUs") under the Issuer's 2021 Equity Incentive Plan that are subject to time-based vesting and will be settled in common stock subject to vesting as follows: the RSUs vest quarterly over the thirty month period following July 9, 2026; in each case, subject to the reporting person providing service through the applicable vesting date. 12.5% of the option shares will vest on February 28, 2027, with the remaining option shares to vest in equal monthly installments over the following 42 months, subject to the reporting person providing service through the applicable vesting date. /s/ Mark Meltz, Attorney-in-Fact 2026-09-10