Lyell Immunopharma, Inc.

Forward-Looking Statements

This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Forward-looking statements expressed or implied in this press release include, but are not limited to, statements regarding: Lyell’s intention to present updated ronde-cel results at ASH 2026; Lyell’s belief that its current cash, cash equivalents and marketable securities, together with the net proceeds from the private placement in November 2026, will be sufficient to meet working capital and capital expenditure needs into 2028; Lyell’s expectations around the progress of the PiNACLE and PiNACLE-H2H trials, including the expected timing for release of additional and pivotal data from the PiNACLE trial, the use of pivotal data from the PiNACLE trial to support a BLA submission to the FDA in the second half of 2027 and other expectations around enrollment and regulatory submissions; Lyell’s planned activities in anticipation of commercialization; Lyell’s expectations around the progress of the U.S. Phase 1/2 trial for LYL273, including the expected timing for release of additional clinical data from this trial, determination of the recommended Phase 2 dose, optimization of the safety management plan, implementation of the improved manufacturing process and updated analytical methods and an End-of-Phase 1 FDA meeting; the anticipated benefits of Orphan Drug, RMAT and Fast Track designations for ronde-cel and Fast Track designation for LYL273; the capability of LyFE to manufacture drug supply through potential commercial launch and its expected manufacturing capacity; the potential clinical benefits and therapeutic potential of Lyell’s product candidates; and other statements that are not historical fact. These statements are based on Lyell’s current plans, objectives, estimates, expectations and intentions, are not guarantees of future performance and inherently involve significant risks and uncertainties. Actual results and the timing of events could differ materially from those anticipated in such forward-looking statements as a result of these risks and uncertainties, which include, but are not limited to, risks and uncertainties related to: Lyell operates in a rapidly evolving industry and has a limited operating history; Lyell’s ability to successfully develop, manufacture and commercialize product candidates or its experiencing significant delays in doing so; Lyell’s dependence on the enrollment and retention of patients in its current and planned clinical trials for its product candidates; the potential for results of Lyell’s research, nonclinical studies or earlier clinical trials to not be predictive of future results; clinical development involving a lengthy and expensive process with uncertain outcomes; Lyell’s product candidates and technologies being based on novel technologies that are unproven and may not result in approvable or marketable products; Lyell facing substantial competition in a rapidly changing industry, which may result in others discovering, developing or commercializing products before or more successfully than it does; Lyell’s ability to obtain and maintain sufficient intellectual property protection for its product candidates; the complexity of manufacturing cellular therapies; Lyell’s ability to manufacture drug products for its clinical trials itself and any potential delays in further qualifying or in receiving regulatory approvals for any manufacturing facility or product candidates or in expanding its manufacturing capacity; Lyell’s reliance on third parties; implementation of Lyell’s strategic plans for its business and product candidates and Lyell’s realization of the expected benefits of such plans; the potential reduction of Lyell’s cash resources and fluctuations in Lyell’s operating results and financial condition as a result of Lyell’s milestone, royalty and success payment obligations; the sufficiency of Lyell’s capital resources and need for additional capital to achieve its goals; and other risks, including those described under the heading “Risk Factors” in Lyell’s Quarterly Report on Form 10-Q for the quarter ended September 30, 2026, being filed with the Securities and Exchange Commission today. Forward-looking statements contained in this press release are made as of this date, and Lyell undertakes no duty to update such information except as required under applicable law.