License Agreement - In 2018, the Company entered into a license agreement with Fred Hutch that grants the Company a worldwide, sublicensable license under certain patent rights (exclusive) and certain technology (non-exclusive), to research, develop and commercialize products and processes for all therapeutic uses for the treatment of human cancer.

Collaboration - In 2018, the Company entered into a research and collaboration agreement with Fred Hutch (“Fred Hutch Collaboration Agreement”), focused on research and development of cancer immunotherapy products. The Company funded aggregate research performed by Fred Hutch of $12.0 million under the Fred Hutch Collaboration Agreement and the research is conducted in accordance with a research plan and budget approved by the parties. The Fred Hutch Collaboration Agreement has a six-year term. During 2021, one of the research plans on which the success payment service term is based, was extended from January 31, 2022 to December 31, 2022. The Company incurred $1.7 million, $4.2 million and $4.1 million in expense in connection with the Fred Hutch Collaboration Agreement for the years ended December 31, 2022, 2021 and 2020, respectively.

Success Payments - In 2018, the Company granted Fred Hutch rights to certain success payments, pursuant to the terms of the Fred Hutch Collaboration Agreement. The potential payments for the Fred Hutch success payments are based on multiples of increased value ranging from 10x to 50x based on a comparison of the per share fair market value of the Company’s common stock (as all shares of Series A convertible preferred stock were converted into an equivalent number of shares of common stock upon the closing of the IPO) relative to its original $1.83 per share issuance price. The aggregate success payments to Fred Hutch are not to exceed $200.0 million, which would only occur upon a 50 times increase in value. Each threshold is associated with a success payment, ascending from $10.0 million at $18.29 per share to $200.0 million at $91.44 per share, payable if such threshold is reached during the measurement period. Any previous success payments made are credited against the success payment owed as of any valuation date, such that Fred Hutch does not receive multiple success payments in connection with the same threshold. The term of the success payment agreement ends on the earlier to occur of (i) the nine-year anniversary of the date of the agreement and (ii) a change in control transaction.

the above outlined multiples. The valuation measurement dates are triggered by the following events: the one-year anniversary of the Company’s IPO and each two-year anniversary of the Company’s IPO thereafter, the closing of a change in control transaction and the last day of the term of the success payment agreement, unless the term has ended due to the closing of a change of control transaction. As of December 31, 2022, no success payments have been incurred as the per share fair value of the Company’s common stock was below the price required for payment.

The estimated fair values of the success payments to Fred Hutch as of December 31, 2022 and 2021 were $2.5 million and $8.5 million, respectively. The success payment liability is estimated at the fair value at inception and at each subsequent reporting period and the expense is accreted over the service period of the Fred Hutch Collaboration Agreement. The success payment liability was $2.5 million and $6.4 million as of December 31, 2022 and 2021, respectively. With respect to the Fred Hutch Collaboration Agreement success payment obligations, the Company recognized a gain of $3.9 million for the year ended December 31, 2022, and success payment expense of $1.2 million and $4.8 million for the years ended December 31, 2021 and 2020, respectively.

License Agreement - In 2019, the Company entered into a license agreement with Stanford to license specified patent rights. The Company is also required to pay Stanford annual license maintenance payments of $50,000 on the second anniversary of the effective date, and each anniversary of the effective date thereafter until the date of the first commercial sale of a licensed product.

Milestone payments to Stanford of up to a maximum of $3.7 million per target are payable upon achievement of certain specified clinical and regulatory milestones. The Company is also obligated to pay Stanford $2.5 million collectively for all licensed products upon the achievement of a certain commercial milestone. Additionally, low single‑digit tiered royalties based on annual net sales of the licensed products are payable to Stanford.

Collaboration Agreement - In October 2020, the Company entered into a research and collaboration agreement with Stanford (“Stanford Collaboration Agreement”), focused on research and development of cellular immunotherapy products. The Stanford Collaboration Agreement has a four-year term. The Company is committed to fund aggregate research performed by Stanford of $12.0 million under the Stanford Collaboration Agreement, and the research will be conducted in accordance with a research plan and budget approved by the parties. The Company incurred $3.0 million, $3.0 million and $0.8 million in expense in connection with the Stanford Collaboration Agreement for the years ended December 31, 2022, 2021, and 2020, respectively.

Success Payments - In October 2020, the Company granted Stanford rights to certain success payments, pursuant to the terms of the Stanford Collaboration Agreement. The potential payments for the Stanford Collaboration Agreement success payments are based on multiples of increased value ranging from 10x to 50x based on a comparison of the per share fair market value of the Company’s common stock (as all shares of Series A convertible preferred stock were converted into an equivalent number of shares of common stock upon the closing of the IPO) relative to its original $1.83 per share issuance price. The aggregate success payments to Stanford are not to exceed $200.0 million, which would only occur upon a 50 times increase in value. Each threshold is associated with a success payment, ascending from $10.0 million at $18.29 per share to $200.0 million at $91.44 per share, payable if such threshold is reached during the measurement period. Any previous success payments made are credited against the success payment owed as of any valuation date, so that Stanford does not receive multiple success payments in connection with the same threshold. The term of each success payment agreement ends on the earlier to occur of (i) the nine year anniversary of the date of the agreement and (ii) a change in control transaction.

The success payments will be owed if the per share fair value of the Company’s common stock on the contractually specified valuation measurement dates during the term of the success payment agreement equals or exceeds the above outlined multiples. The valuation measurement dates are triggered by the following events: the one-year anniversary of the Company’s IPO and each two-year anniversary of the Company’s IPO thereafter, the closing of a change in control transaction and the last day of the term of the success payment agreement, unless the term has ended due to the

The estimated fair values of the success payments to Stanford as of December 31, 2022 and 2021 were $3.3 million and $9.9 million, respectively. The success payment liability is estimated at the fair value at inception and at each subsequent reporting period and the expense is accreted over the service period of the Stanford Collaboration Agreement. The success payment liability was $1.9 million and $3.1 million as of December 31, 2022 and 2021, respectively. With respect to the Stanford Collaboration Agreement success payment obligations, the Company recognized a gain of $1.2 million for the year ended December 31, 2022, and success payment expense of $2.5 million and $0.6 million for the years ended December 31, 2021 and 2020, respectively.

In 2019, the Company entered into the GSK Agreement with GSK for potential T‑cell therapies that apply the Company’s platform technologies and cell therapy innovations with T‑cell receptors (“TCRs”) or chimeric antigen receptors (“CARs”) under distinct collaboration programs. The GSK Agreement defined two initial collaboration targets, LYL331 and LYL132, and allowed GSK to nominate seven additional targets through July 2024, noting no additional targets were nominated over the life of the GSK Agreement. The Company was expected to perform research and development services for each selected target up until a defined point (the “GSK Option Point”), at which time GSK would decide whether or not to exercise an option to obtain a license from the Company (“License Option”) and take over the future development and commercialization. In April 2021, GSK exercised the License Option on LYL331 (NY-ESO-1 TCR with c-Jun) and assumed sole responsibility for future development and commercialization of the program at its own cost and expense. The IND application for LYL132 was cleared in January 2022, though no patients were treated, and the IND for LYL331 was not submitted to the U.S. Food and Drug Administration. GSK terminated the GSK Agreement effective December 24, 2022 and Lyell has discontinued any further work on these programs. There are no future performance obligations associated with the GSK Agreement.

The Company received a non-refundable upfront payment of $45.0 million under the GSK Agreement. In connection with the GSK Agreement, in May 2019, the Company also entered into a stock purchase agreement with GSK (“GSK Stock Purchase Agreement”), pursuant to which the Company agreed to sell 30,253,189 shares of Series AA convertible preferred stock at a price of $6.78 per share, which was above the issuance date estimated fair value of $4.84 per share. The difference between the per share values resulted in $58.6 million additional deemed consideration, bringing the total upfront consideration of the GSK Agreement to $103.6 million.

The GSK Agreement was deemed to be within the scope of ASC 606 because GSK engaged the Company to initially provide research and development services, which were outputs of its ongoing activities, in exchange for consideration. During the year ended December 31, 2022, the Company recorded adjustments to revenue related to changes in estimates to complete its performance obligations under the GSK Agreement. These changes in estimates were driven by the mutual agreement to conclude certain research activities in June 2022 and the termination of the GSK Agreement, effective December 24, 2022, both of which resulted in changes to the measure of proportional cumulative performance. These adjustments increased revenue by $83.6 million, decreased net loss by $83.6 million and resulted in a $0.34 reduction in the Company’s basic and diluted net loss per common share for the year ended December 31, 2022.

The Company recognized revenue related to the research and development services related to the two initial targets of $84.7 million, $10.5 million and $7.8 million for the years ended December 31, 2022, 2021 and 2020 respectively. No license revenue was recognized for the year ended December 31, 2022. As of December 31, 2022 and 2021, the Company had deferred revenue of zero and $84.7 million, respectively, related to the GSK Agreement. As of December 31, 2022, there were no contract assets or contract liabilities related to the license contract.

In June 2020, the Company entered into a commitment agreement (“PACT Commitment Agreement”) with PACT to jointly develop and test a next generation personalized anti-cancer T‑cell therapy against solid tumors. The Company paid PACT an upfront non-refundable payment of $50.0 million upon execution of the PACT Commitment Agreement. In November 2020, the parties agreed to suspend research and development activity under the PACT Commitment Agreement, and neither party would be required to conduct any further work under the development plan (including manufacturing development) nor incur any financial obligations (including milestone payments) that might otherwise arise, for as long as the parties continued to negotiate in good faith to resolve the issues that have arisen between them relating to the PACT Commitment Agreement.

In June 2020 in connection with the entry into the PACT Commitment Agreement, the Company also entered into a stock purchase agreement with PACT (“PACT SPA”), pursuant to which the Company purchased 17,806,901 shares of PACT Series C-1 convertible preferred stock at a purchase price of $2.81 per share. As of the purchase date, the estimated fair value of the Series C-1 convertible preferred stock was $2.05 per share, and the difference between the estimated fair value of the preferred stock as of the purchase date and the purchase price of $13.6 million was deemed to be additional consideration for the PACT Commitment Agreement and recognized as research and development expense. As a result, the total upfront consideration paid in connection with the PACT Commitment Agreement was $63.6 million and was included in research and development expenses. The remaining $36.4 million associated with the PACT Series C-1 convertible preferred stock was recorded in other investments. In the fourth quarter of 2021, the Company fully impaired the remaining balance of $36.4 million. See Note 5, Other Investments, for additional details regarding the PACT investment impairment.

On October 1, 2022, the Company entered into a settlement agreement with PACT, pursuant to which the parties agreed to resolve their outstanding legal dispute. In connection with the settlement agreement, the parties also entered into a stock purchase agreement, pursuant to which PACT issued shares of PACT’s Series D convertible preferred stock to the Company in exchange for the Company’s tender of its PACT Series C-1 convertible preferred stock and resolution of the arbitration. The issuance of PACT’s Series D convertible preferred stock, which are non-voting, have limited conversion rights and carry no right to appoint directors, resulted in the Company’s ownership increasing to approximately 80% of PACT’s fully diluted shares outstanding. The settlement agreement also included the termination of the PACT Commitment Agreement to jointly develop a next generation anti-cancer T‑cell therapy against solid tumors. The Company recorded a gain of $2.9 million on October 1, 2022 for the estimated fair value of the PACT Series D convertible preferred stock received as part of the settlement agreement. The PACT Series D convertible preferred stock was recorded at its estimated fair value as of the settlement date and is included in other investments in the Company’s Consolidated Balance Sheets.