8. Collaboration agreements

Eli Lilly and Company

In October 2023, the Company entered into a Transfer and Delegation Agreement, or the Lilly Agreement, with Eli Lilly and Company, or Lilly, pursuant to which Lilly acquired certain assets and other rights under the Company’s amended collaboration and license agreement, or the Verve Agreement, with Verve Therapeutics, Inc., or Verve, including the Company’s opt-in rights to co-develop and co-commercialize Verve’s base editing programs for cardiovascular disease (see discussion below related to the Verve Agreement). The Company granted Lilly an exclusive sublicense to the Verve technology originally licensed to the Company under the Verve Agreement. Lilly also acquired the right to receive any future milestone or royalty payments payable by Verve under the Verve Agreement and the rights and obligations to designate representatives and participate on the joint steering committee with Verve. The Company received a $200.0 million nonrefundable upfront payment and is eligible to receive up to $350.0 million in potential future development-stage payments upon the completion of certain clinical, regulatory and alliance events. Through March 31, 2026, the Company has recognized a total of $50.0 million of milestone related revenue, including $25.0 million during the three months ended March 31, 2026. As of March 31, 2026, the Company has received $25.0 million of these milestone payments.

The $25.0 million that is due is included in prepaid expenses and other current assets. There was no revenue recognized during the three months ended March 31, 2025. As of March 31, 2026, there was no deferred revenue remaining related to the Lilly Agreement.

Apellis Pharmaceuticals

In June 2021, the Company entered into a research collaboration agreement, or the Apellis Agreement, with Apellis Pharmaceuticals, Inc., or Apellis, focused on the use of certain of the Company’s base editing technology to discover new treatments for complement system-driven diseases. Under the terms of the Apellis Agreement, the Company will conduct preclinical research on six base editing programs that target specific genes within the complement system in various organs, including the eye, liver, and brain. Apellis has an exclusive option to license any or all of the six programs, or in each case, an Opt-In Right, and collectively, the Opt-In Rights, and will assume responsibility for subsequent development. In 2025, Apellis notified the Company of its decision to opt-in to one of the six base editing programs. As a result of Apellis' decision to opt-in to the program, the Company received a cash opt-in fee of $3.8 million which was recognized as revenue during the year ended December 31, 2025. The Company may elect to enter into a 50-50 U.S. co-development and co-commercialization agreement with Apellis with respect to one program licensed under the collaboration. The collaboration is managed on an overall basis by an alliance steering committee formed by an equal number of representatives from the Company and Apellis.

As part of the collaboration, the Company received a total of $75.0 million in upfront and near-term milestones from Apellis, which was comprised of $50.0 million received upon signing and an additional $25.0 million payment on June 30, 2022, the one-year anniversary of the effective date of the Apellis Agreement, or the First Anniversary Payment. Following any exercise of an Opt-In Right for any of the six programs, the Company will be eligible to receive development, regulatory, and sales milestones from Apellis, as well as royalty payments on sales. The collaboration has an initial term of five years and may be extended up to two years on a per year and program-by-program basis. During the collaboration term, Apellis may, subject to certain limitations, substitute a specific complement gene and/or organ for any of the initial base editing programs. Apellis may terminate the Apellis Agreement for convenience on any or all of the programs by providing prior written notice.

The Company accounts for the Apellis Agreement under ASC 606, Revenue from Contracts with Customers, or ASC 606, as it includes a customer-vendor relationship as defined under ASC 606 and meets the criteria to be considered a contract.

The overall transaction price as of the inception of the contract was determined to be $75.0 million, which is composed of the upfront payment of $50.0 million and the First Anniversary Payment of $25.0 million. The Company re-evaluates the transaction price in each reporting period.

The Company concluded that each of the six base editing programs combined with the research and development service, licenses, substitution rights and governance participation were material promises that were both capable of being distinct and were distinct within the context of the Apellis Agreement and represented separate performance obligations. The Company further concluded that the Opt-In Rights and option to extend the collaboration term did not grant Apellis a material right. The Company determined that the term of the contract is five years, as this is the period during which both parties have enforceable rights.

The selling price of each performance obligation was determined based on the Company’s ESSP. The Company developed the ESSP for all of the performance obligations included in the Apellis Agreement by determining the total estimated costs to fulfill each performance obligation identified with the objective of determining the price at which it would sell such an item if it were to be sold regularly on a standalone basis. The Company allocated the stand-alone selling price to the performance obligations based on the relative standalone selling price method.

The Company recognizes revenue for each performance obligation as it is satisfied over the five-year term using an input method. The Company allocated the transaction price of $75.0 million to each of the six performance obligations, which includes each of the six base editing programs combined with the research and development service, licenses, substitution rights and governance participation, and is being recognized using an input method based on the actual costs incurred as a percentage of total estimated costs towards satisfying the performance obligation as this method provides the most faithful depiction of the entity’s performance in transferring control of the goods and services promised to Apellis and represents the Company’s best estimate of the period of the obligation. The Company recognized $6.7 million and $5.3 million of revenue related to the Apellis Agreement during the three months ended March 31, 2026 and 2025, respectively. As of March 31, 2026, there was $0.3 million of current deferred revenue related to the Apellis Agreement. The initial five year term of the collaboration extends through June 2026 with an option to extend for up to two additional years. If the agreement is not extended, the remaining deferred revenue will be recognized at that time.

On March 31, 2026, Biogen Inc. announced that it and Apellis had entered into a definitive agreement under which Biogen has agreed to acquire all outstanding shares of Apellis. The transaction is expected to close in the second quarter of 2026.