Collaboration and License Agreements	9 Months Ended
Sep. 30, 2026
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Collaboration and License Agreements	8. Collaboration agreements Eli Lilly and Company In October 2023, the Company entered into a Transfer and Delegation Agreement, or the Lilly Agreement, with 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, 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 September 30, 2026, the Company has recognized and received a total of $50.0 million of milestone related revenue, including $25.0 million during the nine months ended September 30, 2026. There was no revenue recognized under the Lilly Agreement during the three and nine months ended September 30, 2025. As of September 30, 2026, there was no deferred revenue remaining related to the Lilly Agreement. Apellis Pharmaceuticals and Biogen Inc. In June 2021, the Company entered into a research collaboration agreement, or the Apellis Agreement, with Apellis Pharmaceuticals, Inc., or Apellis, which was acquired by Biogen Inc., or Biogen, in May 2026, 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 conducted 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 had 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 would 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. In September 2026, Biogen notified the Company of its decision to terminate its rights with respect to the FcRN base editing program, effective December 2026. 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 was eligible to receive development, regulatory, and sales milestones from Apellis, as well as royalty payments on sales. The collaboration had an initial term of five years and could have been extended up to two years on a per year and program-by-program basis. Pursuant to the terms of the Apellis Agreement, the Company’s obligation to provide services concluded as of June 30, 2026 as Apellis did not elect to extend the agreement beyond the initial term. 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 estimated standalone selling price, or 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 recognized revenue for each performance obligation as it was 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 included each of the six base editing programs combined with the research and development service, licenses, substitution rights and governance participation, and was 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 provided the most faithful depiction of the entity’s performance in transferring control of the goods and services promised to Apellis and represented the Company’s best estimate of the period of the obligation. The Company did not recognize any revenue related to the Apellis Agreement during the three months ended September 30, 2026 and recognized $7.2 million of revenue related to the Apellis Agreement during the nine months ended September 30, 2026. The Company recognized $7.6 million and $19.3 million of revenue related to the Apellis Agreement during the three and nine months ended September 30, 2025, respectively, which includes the $3.8 million of revenue related to Apellis' decision to opt-in to one of the six base editing programs. As of September 30, 2026, there was no remaining deferred revenue related to the Apellis Agreement.

Collaboration and License Agreements

9 Months Ended

Sep. 30, 2026

Organization, Consolidation and Presentation of Financial Statements [Abstract]

8. Collaboration agreements

Eli Lilly and Company

In October 2023, the Company entered into a Transfer and Delegation Agreement, or the Lilly Agreement, with 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, 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 September 30, 2026, the Company has recognized and received a total of $50.0 million of milestone related revenue, including $25.0 million during the nine months ended September 30, 2026. There was no revenue recognized under the Lilly Agreement during the three and nine months ended September 30, 2025. As of September 30, 2026, there was no deferred revenue remaining related to the Lilly Agreement.

Apellis Pharmaceuticals and Biogen Inc.

In June 2021, the Company entered into a research collaboration agreement, or the Apellis Agreement, with Apellis Pharmaceuticals, Inc., or Apellis, which was acquired by Biogen Inc., or Biogen, in May 2026, 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 conducted 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 had 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 would 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. In September 2026, Biogen notified the Company of its decision to terminate its rights with respect to the FcRN base editing program, effective December 2026.

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 was eligible to receive development, regulatory, and sales milestones from Apellis, as well as royalty payments on sales. The collaboration had an initial term of five years and could have been extended up to two years on a per year and program-by-program basis. Pursuant to the terms of the Apellis Agreement, the Company’s obligation to provide services concluded as of June 30, 2026 as Apellis did not elect to extend the agreement beyond the initial term.

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 estimated standalone selling price, or 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 recognized revenue for each performance obligation as it was 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 included each of the six base editing programs combined with the research and development service, licenses, substitution rights and governance participation, and was 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 provided the most faithful depiction of the entity’s performance in transferring control of the goods and services promised to Apellis and represented the Company’s best estimate of the period of the obligation. The Company did not recognize any revenue related to the Apellis Agreement during the three months ended September 30, 2026 and recognized $7.2 million of revenue related to the Apellis Agreement during the nine months ended September 30, 2026. The Company recognized $7.6 million and $19.3 million of revenue related to the Apellis Agreement during the three and nine months ended September 30, 2025, respectively, which includes the $3.8 million of revenue related to Apellis' decision to opt-in to one of the six base editing programs. As of September 30, 2026, there was no remaining deferred revenue related to the Apellis Agreement.