Significant Contracts	12 Months Ended
Dec. 31, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Significant Contracts	8. Significant Contracts Agreements with Vertex For purposes of this Note 8 and Note 9, CASGEVY (exagamglogene autotemcel [exa-cel]) is referred to as “CASGEVY”. 2015 collaboration In 2015, the Company entered into a strategic collaboration, option and license agreement, or the 2015 Collaboration Agreement, with Vertex. The 2015 Collaboration Agreement is focused on the use of the Company’s CRISPR/Cas9 gene editing technology to discover and develop potential new treatments aimed at the underlying genetic causes of human disease. The Company and Vertex amended the 2015 Collaboration Agreement in 2017 and 2019 with Amendment No. 1 and Amendment No. 2, respectively, namely to clarify Vertex’s option rights under the 2015 Collaboration Agreement and to modify certain definitions and provisions of the 2015 Collaboration Agreement to make them consistent with the JDA (as defined below) and a strategic collaboration and license agreement from 2019 for the development and commercialization of products for the treatment of Duchenne muscular dystrophy and myotonic dystrophy Type 1. In 2017, Vertex exercised an option granted to it under the 2015 Collaboration Agreement to obtain a co-exclusive license to develop and commercialize hemoglobinopathy and beta-globin targets, and in 2019, Vertex exercised the remaining options granted to it under the 2015 Collaboration Agreement to exclusively license certain collaboration targets developed under the 2015 Collaboration Agreement. Hemoglobinopathies collaboration In 2017, following Vertex's exercise of its option to obtain a co-exclusive license to develop and commercialize hemoglobinopathy and beta-globin targets, the Company and Vertex entered into a joint development and commercialization agreement, or the JDA, and agreed for potential hemoglobinopathy treatments, including CASGEVY, the Company and Vertex would share equally all research and development costs and worldwide revenues. In 2021, the Company and Vertex amended and restated the JDA, or the A&R Vertex JDCA (as amended and in effect, from time to time), pursuant to which the parties agreed to, among other things, (a) adjust the governance structure for the collaboration and adjust the responsibilities of each party thereunder, whereby Vertex leads and has all decision making (i.e., control) in relation to the CASGEVY program prospectively; (b) adjust the allocation of net profits and net losses between the parties with respect to CASGEVY only, which will be allocated 40% to the Company and 60% to Vertex, prospectively; and (c) exclusively license (subject to the Company’s reserved rights to conduct certain activities) certain intellectual property rights to Vertex relating to the specified product candidates and products (including CASGEVY) that may be researched, developed, manufactured and commercialized on a worldwide basis under the A&R Vertex JDCA. Additionally, the A&R Vertex JDCA allows the Company to defer a portion of its share of costs under the arrangement if spending on the CASGEVY program exceeds specified amounts through 2024. In December 2023, the Company entered into an amendment to the A&R Vertex JDCA, or Amendment No. 1 to the A&R Vertex JDCA, with Vertex related to the global development, manufacturing, and commercialization of CASGEVY. Pursuant to Amendment No. 1 to the A&R Vertex JDCA, among other things, the Company and Vertex agreed to (a) allocate certain costs arising from a license agreement with a third party, resulting in a current payment due to Vertex by the Company of $20.0 million upon an event specified in Amendment No. 1 to the A&R Vertex JDCA, and (b) adjust, under certain specified circumstances, the timing of and portion of the Company’s share of costs it is permitted to defer under the agreement. Any deferred amounts under the A&R Vertex JDCA, as amended, are only payable to Vertex as an offset against future profitability of the CASGEVY program and the amounts payable are capped at a specified maximum amount per year. In connection with the closing of the transaction contemplated by the A&R Vertex JDCA, the Company received a $900.0 million up-front payment from Vertex. Additionally, in December 2023, the Company and Vertex received approval of CASGEVY by the U.S. Food and Drug Administration, or the FDA. The FDA’s approval of CASGEVY triggered Vertex’s obligation to make a $200.0 million milestone payment to the Company. Letter Agreement In May 2024, Vertex and the Company entered into a letter agreement, or the Letter Agreement, with respect to the priority review voucher issued by the FDA to Vertex as the sponsor of the rare pediatric disease product application for CASGEVY. Vertex and the Company agreed that if Vertex utilizes or transfers the priority review voucher prior to the first calendar year in which the CASGEVY program generates a net profit, Vertex will pay the Company $43.0 million or an amount equal to 42% of the net proceeds from such transfer, as applicable. If the CASGEVY program begins generating calendar-year net profits prior to such utilization or transfer, Vertex will instead pay the Company up to $43.0 million, set-off by deductions Vertex would otherwise be eligible to take against the CASGEVY program's net profits due to the Company related to amounts deferred previously by the Company. Collaboration in the field of diabetes In 2021, the Company and ViaCyte, Inc., or ViaCyte, entered into a joint development and commercialization agreement, or the ViaCyte JDCA, to jointly develop and commercialize product candidates and shared products for the diagnosis, treatment or prevention of diabetes type 1, diabetes type 2 or insulin dependent / requiring diabetes throughout the world. In the third quarter of 2022, Vertex acquired ViaCyte, and ViaCyte became a wholly-owned subsidiary of Vertex. In March 2023, (1) the Company and ViaCyte entered into an amendment to the ViaCyte JDCA, or the ViaCyte JDCA Amendment, and adjusted certain rights and obligations of the Company and ViaCyte under the ViaCyte JDCA, and (2) the Company and Vertex entered into a non-exclusive license agreement, or the Non-Ex License Agreement, pursuant to which the Company agreed to license to Vertex, on a non-exclusive basis, certain of its gene editing intellectual property to exploit certain products for the diagnosis, treatment or prevention of diabetes type 1, diabetes type 2 or insulin dependent / requiring diabetes throughout the world. Subsequently, ViaCyte elected to opt-out of the ViaCyte JDCA. Per the opt-out terms, the on-going collaboration assets are now wholly owned by the Company, subject to a royalty on future sales owed to ViaCyte. The opt-out became effective in February 2024. In connection with entering into the Non-Ex License Agreement in 2023, the Company received a $100.0 million up front payment from Vertex and subsequently received a $70.0 million research milestone achieved in the second quarter of 2023. In 2024, the Company received a $10.0 million research milestone achieved in the fourth quarter of 2024 and recorded a receivable of $25.0 million as of December 31, 2024 related to an additional research milestone achieved under the Non-Ex License Agreement in the fourth quarter of 2024. The Company is eligible to receive additional milestone payments under the Non-Ex License Agreement of $125.0 million in aggregate, which are dependent on the achievement of pre-determined research, development and commercial milestones for certain products utilizing the licensed intellectual property. Additionally, the Company is eligible to receive tiered royalties on the sales of certain products in the low to mid-single digits. Accounting Analysis For purposes of this Note 8, the 2015 Collaboration Agreement, Amendment No. 1, Amendment No. 2, A&R Vertex JDCA, and Amendment No. 1 to the A&R Vertex JDCA are collectively referred to as the “Vertex Hemoglobinopathy Agreements” and the Non-Ex License Agreement and ViaCyte JDCA Amendment are collectively referred to as the “March 2023 Diabetes Agreements.” The Vertex Hemoglobinopathy Agreements and the March 2023 Diabetes Agreements include components of a customer-vendor relationship as defined under ASC 606, collaborative arrangements as defined under ASC 808, Collaborative Agreements, or ASC 808, and research and development costs as defined under ASC 730, Research and Development, or ASC 730. Specifically, with regards to the March 2023 Diabetes Agreements, the Company concluded that the non-exclusive license is a performance obligation under ASC 606 and the ongoing research and development services under the ViaCyte JDCA Amendment are a unit of account under ASC 808. The Company has determined that recognition criteria for the Letter Agreement has not been met and will not be met until the priority review voucher is (i) utilized or (ii) there is sufficient profitability such that Vertex is obligated to pay the Company under the Letter Agreement. Accounting Analysis Under ASC 606 March 2023 Diabetes Agreements Identification of the Contract The March 2023 Diabetes Agreements were negotiated as a package with a single commercial objective and, as such, the March 2023 Diabetes Agreements were combined for accounting purposes and treated as a single arrangement. The Company determined for accounting purposes that the combined contract terminated the original ViaCyte JDCA and created a new contract. Identification of Performance Obligations The Company concluded the transfer of the non-exclusive license, including certain modified rights and obligations provided as part of the ViaCyte JDCA Amendment to support the delivery of the license, was both capable of being distinct and distinct within the context of the contract. Determination of Transaction Price The initial transaction price was comprised of the upfront payment of $100.0 million. In the second quarter of 2023, the Company adjusted the transaction price to include $70.0 million in previously constrained variable consideration related to a research milestone which was achieved in the second quarter of 2023. In the fourth quarter of 2024, the Company adjusted the transaction price to include $35.0 million in previously constrained variable considerations related to two research milestones that were achieved in the fourth quarter of 2024. The Company determined that all other possible variable consideration resulting from milestones and royalties discussed below was fully constrained as of December 31, 2024. The Company will re-evaluate the transaction price in each reporting period. Allocation of Transaction Price to Performance Obligations The Company identified one performance obligation for the March 2023 Diabetes Agreements and, as a result, no allocation of the transaction price was required. Recognition of Revenue The Company determined the non-exclusive license, including certain modified rights and obligations provided as part of the ViaCyte JDCA Amendment to support the delivery of the license, represented functional intellectual property, as the intellectual property provides Vertex with the ability to perform a function or task in the form of research and development in the field of diabetes. In 2023, the Company recognized revenue of $100.0 million for the non-exclusive license at the onset of the arrangement, as this was the point in time in which the non-exclusive license was delivered, as well as revenue of $70.0 million from previously constrained variable consideration related to a research milestone achieved in the second quarter of 2023. Revenue recognized under the March 2023 Diabetes Agreements for the year ended December 31, 2023 was $170.0 million. Revenue recognized under the March 2023 Diabetes Agreements for year ended December 31, 2024 was $35.0 million and related to previously constrained variable consideration related to two research milestones achieved during the fourth quarter of 2024. Milestones under the Non-Ex License Agreement As of December 31, 2024, the Company is eligible to receive potential future milestone payments from Vertex of up to $125.0 million in the aggregate under the Non-Ex License Agreement depending on the achievement of pre-determined research, development and commercial milestones for certain products utilizing the licensed intellectual property. Additionally, the Company is eligible to receive tiered royalties on the sales of certain products in the low to mid-single digits. Each of the remaining milestones under the Non-Ex License Agreement are fully constrained as of December 31, 2024. There is uncertainty as to whether the events to obtain the research and developmental milestones will be achieved given the nature of clinical development and the stage of the CRISPR/Cas9 technology. The remaining research, development and regulatory milestones will be constrained until it is probable that a significant revenue reversal will not occur. Commercial milestones and royalties relate predominantly to a license of intellectual property and are determined by sales or usage-based thresholds. The commercial milestones and royalties are accounted for under the royalty recognition constraint and will be accounted for as constrained variable consideration. The Company applies the royalty recognition constraint for each commercial milestone and will not recognize revenue for each until the subsequent sale of a licensed product (achievement of each) occurs. Accounting for the Vertex Hemoglobinopathy Agreements Recognition of Revenue Revenue recognized under the Vertex Hemoglobinopathy Agreements for the year ended December 31, 2023 was $200.0 million of previously constrained variable consideration related to a milestone that was achieved upon approval of CASGEVY by the Food and Drug Administration, or FDA, in December 2023. No revenue was recognized under the Vertex Hemoglobinopathy Agreements for the year ended December 31, 2024. Deferred Revenue As of December 31, 2024 and 2023 there was no current deferred revenue related to the Vertex Hemoglobinopathy Agreements. As of December 31, 2024 and 2023, there was $12.3 million of non-current deferred revenue related to the Vertex Hemoglobinopathy Agreements. The transaction price allocated to the remaining performance obligations was $12.3 million. Milestones under the Vertex Hemoglobinopathy Agreements The Company has evaluated the milestones that may be received in connection with the Vertex Hemoglobinopathy Agreements. Under the 2015 Collaboration Agreement and subsequent amendments, the Company is eligible to receive up to $410.0 million in additional development, regulatory and commercial milestones and royalties on net product sales for each of the three collaboration targets that Vertex licensed in 2019. Each milestone is payable only once per collaboration target, regardless of the number of products directed to such collaboration target that achieve the relevant milestone event. The Company is eligible to receive potential future payments of up to $775.0 million under a strategic collaboration and license agreement from 2019 for the development and commercialization of products for the treatment of Duchenne muscular dystrophy and myotonic dystrophy Type 1. The Company is also eligible to receive tiered royalties on future net sales on any products that may result from this collaboration; however, the Company has the option to forego the DM1 milestones and royalties to co-develop and co-commercialize all DM1 products globally. The Company has the option to conduct research at its own cost in certain defined areas. If such research is beneficial to the CASGEVY program and CASGEVY ultimately achieves regulatory approval in such areas, the Company could be entitled to receive from Vertex certain milestone payments aggregating to high eight digits. Each of the remaining milestones described above are fully constrained as of December 31, 2024. There is uncertainty that the events to obtain the research and developmental milestones will be achieved given the nature of clinical development and the stage of the CRISPR/Cas9 technology. The remaining research, development and regulatory milestones will be constrained until it is probable that a significant revenue reversal will not occur. Commercial milestones and royalties relate predominantly to a license of intellectual property and are determined by sales or usage-based thresholds. The commercial milestones and royalties are accounted for under the royalty recognition constraint and will be accounted for as constrained variable consideration. The Company applies the royalty recognition constraint for each commercial milestone and will not recognize revenue for each until the subsequent sale of a licensed product (achievement of each) occurs. Accounting Analysis under ASC 808 Vertex Hemoglobinopathy Agreements In connection with the Vertex Hemoglobinopathy Agreements, the Company identified the following collaborative elements, which are accounted for under ASC 808: (i) development and commercialization services for shared products, including any transition services related to CASGEVY under the A&R Vertex JDCA; (ii) R&D Services for follow-on products; and (iii) committee participation. The related impact of the cost sharing is included within collaboration expense, net, in the consolidated statements of operations and comprehensive loss. During the years ended December 31, 2024, 2023 and 2022, the Company recognized $110.3 million, $130.3 million and $110.3 million of collaboration expense, net, related to the CASGEVY program, respectively. Collaboration expense, net, during the years ended December 31, 2024, 2023 and 2022 was net of $3.2 million, $18.0 million and $37.8 million of reimbursements from Vertex related to the CASGEVY program, respectively. Under the A&R Vertex JDCA, the Company has an option to defer its portion of specified costs on the CASGEVY program in excess of $110.3 million for the years ended December 31, 2022, 2023 and 2024. Additionally, the Company is permitted, under certain specified circumstances as set forth in Amendment No. 1 to the A&R Vertex JDCA, to adjust the timing of and portion of the Company's share of costs it is permitted to defer. The $110.3 million does not include a $20.0 million payment to Vertex recognized in the fourth quarter of 2023 and paid in the first quarter of 2024 in connection with Amendment No. 1 to the A&R Vertex JDCA. In 2024, 2023 and 2022, the Company exercised its option to defer specified costs on the CASGEVY program in excess of the deferral limit under A&R Vertex JDCA, as amended, which is further described in Note 9 of the notes to the consolidated financial statements included in this Annual Report on Form 10-K.

Significant Contracts

12 Months Ended

Dec. 31, 2024

Organization, Consolidation and Presentation of Financial Statements [Abstract]

8. Significant Contracts

Agreements with Vertex

For purposes of this Note 8 and Note 9, CASGEVY (exagamglogene autotemcel [exa-cel]) is referred to as “CASGEVY”.

2015 collaboration

In 2015, the Company entered into a strategic collaboration, option and license agreement, or the 2015 Collaboration Agreement, with Vertex. The 2015 Collaboration Agreement is focused on the use of the Company’s CRISPR/Cas9 gene editing technology to discover and develop potential new treatments aimed at the underlying genetic causes of human disease. The Company and Vertex amended the 2015 Collaboration Agreement in 2017 and 2019 with Amendment No. 1 and Amendment No. 2, respectively, namely to clarify Vertex’s option rights under the 2015 Collaboration Agreement and to modify certain definitions and provisions of the 2015 Collaboration Agreement to make them consistent with the JDA (as defined below) and a strategic collaboration and license agreement from 2019 for the development and commercialization of products for the treatment of Duchenne muscular dystrophy and myotonic dystrophy Type 1. In 2017, Vertex exercised an option granted to it under the 2015 Collaboration Agreement to obtain a co-exclusive license to develop and commercialize hemoglobinopathy and beta-globin targets, and in 2019, Vertex exercised the remaining options granted to it under the 2015 Collaboration Agreement to exclusively license certain collaboration targets developed under the 2015 Collaboration Agreement.

Hemoglobinopathies collaboration

In 2017, following Vertex's exercise of its option to obtain a co-exclusive license to develop and commercialize hemoglobinopathy and beta-globin targets, the Company and Vertex entered into a joint development and commercialization agreement, or the JDA, and agreed for potential hemoglobinopathy treatments, including CASGEVY, the Company and Vertex would share equally all research and development costs and worldwide revenues. In 2021, the Company and Vertex amended and restated the JDA, or the A&R Vertex JDCA (as amended and in effect, from time to time), pursuant to which the parties agreed to, among other things, (a) adjust the governance structure for the collaboration and adjust the responsibilities of each party thereunder, whereby Vertex leads and has all decision making (i.e., control) in relation to the CASGEVY program prospectively; (b) adjust the allocation of net profits and net losses between the parties with respect to CASGEVY only, which will be allocated 40% to the Company and 60% to Vertex, prospectively; and (c) exclusively license (subject to the Company’s reserved rights to conduct certain activities) certain intellectual property rights to Vertex relating to the specified product candidates and products (including CASGEVY) that may be researched, developed, manufactured and commercialized on a worldwide basis under the A&R Vertex JDCA. Additionally, the A&R Vertex JDCA allows the Company to defer a portion of its share of costs under the arrangement if spending on the CASGEVY program exceeds specified amounts through 2024. In December 2023, the Company entered into an amendment to the A&R Vertex JDCA, or Amendment No. 1 to the A&R Vertex JDCA, with Vertex related to the global development, manufacturing, and commercialization of CASGEVY. Pursuant to Amendment No. 1 to the A&R Vertex JDCA, among other things, the Company and Vertex agreed to (a) allocate certain costs arising from a license agreement with a third party, resulting in a current payment due to Vertex by the Company of $20.0 million upon an event specified in Amendment No. 1 to the A&R Vertex JDCA, and (b) adjust, under certain specified circumstances, the timing of and portion of the Company’s share of costs it is permitted to defer under the agreement. Any deferred amounts under the A&R Vertex JDCA, as amended, are only payable to Vertex as an offset against future profitability of the CASGEVY program and the amounts payable are capped at a specified maximum amount per year.

In connection with the closing of the transaction contemplated by the A&R Vertex JDCA, the Company received a $900.0 million up-front payment from Vertex. Additionally, in December 2023, the Company and Vertex received approval of CASGEVY by the U.S. Food and Drug Administration, or the FDA. The FDA’s approval of CASGEVY triggered Vertex’s obligation to make a $200.0 million milestone payment to the Company.

Letter Agreement

In May 2024, Vertex and the Company entered into a letter agreement, or the Letter Agreement, with respect to the priority review voucher issued by the FDA to Vertex as the sponsor of the rare pediatric disease product application for CASGEVY. Vertex and the Company agreed that if Vertex utilizes or transfers the priority review voucher prior to the first calendar year in which the CASGEVY program generates a net profit, Vertex will pay the Company $43.0 million or an amount equal to 42% of the net proceeds from such transfer, as applicable. If the CASGEVY program begins generating calendar-year net profits prior to such utilization or transfer, Vertex will instead pay the Company up to $43.0 million, set-off by deductions Vertex would otherwise be eligible to take against the CASGEVY program's net profits due to the Company related to amounts deferred previously by the Company.

Collaboration in the field of diabetes

In 2021, the Company and ViaCyte, Inc., or ViaCyte, entered into a joint development and commercialization agreement, or the ViaCyte JDCA, to jointly develop and commercialize product candidates and shared products for the diagnosis, treatment or prevention of diabetes type 1, diabetes type 2 or insulin dependent / requiring diabetes throughout the world. In the third quarter of 2022, Vertex acquired ViaCyte, and ViaCyte became a wholly-owned subsidiary of Vertex. In March 2023, (1) the Company and ViaCyte entered into an amendment to the ViaCyte JDCA, or the ViaCyte JDCA Amendment, and adjusted certain rights and obligations of the Company and ViaCyte under the ViaCyte JDCA, and (2) the Company and Vertex entered into a non-exclusive license agreement, or the Non-Ex License Agreement, pursuant to which the Company agreed to license to Vertex, on a non-exclusive basis, certain of its gene editing intellectual property to exploit certain products for the diagnosis, treatment or prevention of diabetes type 1, diabetes type 2 or insulin dependent / requiring diabetes throughout the world. Subsequently, ViaCyte elected to opt-out of the ViaCyte JDCA. Per the opt-out terms, the on-going collaboration assets are now wholly owned by the Company, subject to a royalty on future sales owed to ViaCyte. The opt-out became effective in February 2024.

In connection with entering into the Non-Ex License Agreement in 2023, the Company received a $100.0 million up front payment from Vertex and subsequently received a $70.0 million research milestone achieved in the second quarter of 2023. In 2024, the Company received a $10.0 million research milestone achieved in the fourth quarter of 2024 and recorded a receivable of $25.0 million as of December 31, 2024 related to an additional research milestone achieved under the Non-Ex License Agreement in the fourth quarter of 2024. The Company is eligible to receive additional milestone payments under the Non-Ex License Agreement of $125.0 million in aggregate, which are dependent on the achievement of pre-determined research, development and commercial milestones for certain products utilizing the licensed intellectual property. Additionally, the Company is eligible to receive tiered royalties on the sales of certain products in the low to mid-single digits.

Accounting Analysis

For purposes of this Note 8, the 2015 Collaboration Agreement, Amendment No. 1, Amendment No. 2, A&R Vertex JDCA, and Amendment No. 1 to the A&R Vertex JDCA are collectively referred to as the “Vertex Hemoglobinopathy Agreements” and the Non-Ex License Agreement and ViaCyte JDCA Amendment are collectively referred to as the “March 2023 Diabetes Agreements.”

The Vertex Hemoglobinopathy Agreements and the March 2023 Diabetes Agreements include components of a customer-vendor relationship as defined under ASC 606, collaborative arrangements as defined under ASC 808, Collaborative Agreements, or ASC 808, and research and development costs as defined under ASC 730, Research and Development, or ASC 730. Specifically, with regards to the March 2023 Diabetes Agreements, the Company concluded that the non-exclusive license is a performance obligation under ASC 606 and the ongoing research and development services under the ViaCyte JDCA Amendment are a unit of account under ASC 808.

The Company has determined that recognition criteria for the Letter Agreement has not been met and will not be met until the priority review voucher is (i) utilized or (ii) there is sufficient profitability such that Vertex is obligated to pay the Company under the Letter Agreement.

Accounting Analysis Under ASC 606

March 2023 Diabetes Agreements

Identification of the Contract

The March 2023 Diabetes Agreements were negotiated as a package with a single commercial objective and, as such, the March 2023 Diabetes Agreements were combined for accounting purposes and treated as a single arrangement. The Company determined for accounting purposes that the combined contract terminated the original ViaCyte JDCA and created a new contract.

Identification of Performance Obligations

The Company concluded the transfer of the non-exclusive license, including certain modified rights and obligations provided as part of the ViaCyte JDCA Amendment to support the delivery of the license, was both capable of being distinct and distinct within the context of the contract.

Determination of Transaction Price

The initial transaction price was comprised of the upfront payment of $100.0 million.

In the second quarter of 2023, the Company adjusted the transaction price to include $70.0 million in previously constrained variable consideration related to a research milestone which was achieved in the second quarter of 2023. In the fourth quarter of 2024, the Company adjusted the transaction price to include $35.0 million in previously constrained variable considerations related to two research milestones that were achieved in the fourth quarter of 2024. The Company determined that all other possible variable consideration resulting from milestones and royalties discussed below was fully constrained as of December 31, 2024. The Company will re-evaluate the transaction price in each reporting period.

Allocation of Transaction Price to Performance Obligations

The Company identified one performance obligation for the March 2023 Diabetes Agreements and, as a result, no allocation of the transaction price was required.

Recognition of Revenue

The Company determined the non-exclusive license, including certain modified rights and obligations provided as part of the ViaCyte JDCA Amendment to support the delivery of the license, represented functional intellectual property, as the intellectual property provides Vertex with the ability to perform a function or task in the form of research and development in the field of diabetes. In 2023, the Company recognized revenue of $100.0 million for the non-exclusive license at the onset of the arrangement, as this was the point in time in which the non-exclusive license was delivered, as well as revenue of $70.0 million from previously constrained variable consideration related to a research milestone achieved in the second quarter of 2023. Revenue recognized under the March 2023 Diabetes Agreements for the year ended December 31, 2023 was $170.0 million.

Revenue recognized under the March 2023 Diabetes Agreements for year ended December 31, 2024 was $35.0 million and related to previously constrained variable consideration related to two research milestones achieved during the fourth quarter of 2024.

Milestones under the Non-Ex License Agreement

As of December 31, 2024, the Company is eligible to receive potential future milestone payments from Vertex of up to $125.0 million in the aggregate under the Non-Ex License Agreement depending on the achievement of pre-determined research, development and commercial milestones for certain products utilizing the licensed intellectual property. Additionally, the Company is eligible to receive tiered royalties on the sales of certain products in the low to mid-single digits.

Each of the remaining milestones under the Non-Ex License Agreement are fully constrained as of December 31, 2024. There is uncertainty as to whether the events to obtain the research and developmental milestones will be achieved given the nature of clinical development and the stage of the CRISPR/Cas9 technology. The remaining research, development and regulatory milestones will be constrained until it is probable that a significant revenue reversal will not occur. Commercial milestones and royalties relate predominantly to a license of intellectual property and are determined by sales or usage-based thresholds. The commercial milestones and royalties are accounted for under the royalty recognition constraint and will be accounted for as constrained variable consideration. The Company applies the royalty recognition constraint for each commercial milestone and will not recognize revenue for each until the subsequent sale of a licensed product (achievement of each) occurs.

Accounting for the Vertex Hemoglobinopathy Agreements

Recognition of Revenue

Revenue recognized under the Vertex Hemoglobinopathy Agreements for the year ended December 31, 2023 was $200.0 million of previously constrained variable consideration related to a milestone that was achieved upon approval of CASGEVY by the Food and Drug Administration, or FDA, in December 2023. No revenue was recognized under the Vertex Hemoglobinopathy Agreements for the year ended December 31, 2024.

Deferred Revenue

As of December 31, 2024 and 2023 there was no current deferred revenue related to the Vertex Hemoglobinopathy Agreements. As of December 31, 2024 and 2023, there was $12.3 million of non-current deferred revenue related to the Vertex Hemoglobinopathy Agreements. The transaction price allocated to the remaining performance obligations was $12.3 million.

Milestones under the Vertex Hemoglobinopathy Agreements

The Company has evaluated the milestones that may be received in connection with the Vertex Hemoglobinopathy Agreements.

Under the 2015 Collaboration Agreement and subsequent amendments, the Company is eligible to receive up to $410.0 million in additional development, regulatory and commercial milestones and royalties on net product sales for each of the three collaboration targets that Vertex licensed in 2019. Each milestone is payable only once per collaboration target, regardless of the number of products directed to such collaboration target that achieve the relevant milestone event.

The Company is eligible to receive potential future payments of up to $775.0 million under a strategic collaboration and license agreement from 2019 for the development and commercialization of products for the treatment of Duchenne muscular dystrophy and myotonic dystrophy Type 1. The Company is also eligible to receive tiered royalties on future net sales on any products that may result from this collaboration; however, the Company has the option to forego the DM1 milestones and royalties to co-develop and co-commercialize all DM1 products globally.

The Company has the option to conduct research at its own cost in certain defined areas. If such research is beneficial to the CASGEVY program and CASGEVY ultimately achieves regulatory approval in such areas, the Company could be entitled to receive from Vertex certain milestone payments aggregating to high eight digits.

Each of the remaining milestones described above are fully constrained as of December 31, 2024. There is uncertainty that the events to obtain the research and developmental milestones will be achieved given the nature of clinical development and the stage of the CRISPR/Cas9 technology. The remaining research, development and regulatory milestones will be constrained until it is probable that a significant revenue reversal will not occur. Commercial milestones and royalties relate predominantly to a license of intellectual property and are determined by sales or usage-based thresholds. The commercial milestones and royalties are accounted for under the royalty recognition constraint and will be accounted for as constrained variable consideration. The Company applies the royalty recognition constraint for each commercial milestone and will not recognize revenue for each until the subsequent sale of a licensed product (achievement of each) occurs.

Accounting Analysis under ASC 808

Vertex Hemoglobinopathy Agreements

In connection with the Vertex Hemoglobinopathy Agreements, the Company identified the following collaborative elements, which are accounted for under ASC 808: (i) development and commercialization services for shared products, including any transition services related to CASGEVY under the A&R Vertex JDCA; (ii) R&D Services for follow-on products; and (iii) committee participation. The related impact of the cost sharing is included within collaboration expense, net, in the consolidated statements of operations and comprehensive loss.

During the years ended December 31, 2024, 2023 and 2022, the Company recognized $110.3 million, $130.3 million and $110.3 million of collaboration expense, net, related to the CASGEVY program, respectively. Collaboration expense, net, during the years ended December 31, 2024, 2023 and 2022 was net of $3.2 million, $18.0 million and $37.8 million of reimbursements from Vertex related to the CASGEVY program, respectively.

Under the A&R Vertex JDCA, the Company has an option to defer its portion of specified costs on the CASGEVY program in excess of $110.3 million for the years ended December 31, 2022, 2023 and 2024. Additionally, the Company is permitted, under certain specified circumstances as set forth in Amendment No. 1 to the A&R Vertex JDCA, to adjust the timing of and portion of the Company's share of costs it is permitted to defer. The $110.3 million does not include a $20.0 million payment to Vertex recognized in the fourth quarter of 2023 and paid in the first quarter of 2024 in connection with Amendment No. 1 to the A&R Vertex JDCA. In 2024, 2023 and 2022, the Company exercised its option to defer specified costs on the CASGEVY program in excess of the deferral limit under A&R Vertex JDCA, as amended, which is further described in Note 9 of the notes to the consolidated financial statements included in this Annual Report on Form 10-K.