Collaboration and License Agreement	12 Months Ended
Dec. 31, 2020
Organization Consolidation And Presentation Of Financial Statements [Abstract]
COLLABORATION AND LICENSE AGREEMENT	15. COLLABORATION AND LICENSE AGREEMENT Summary of Agreement In November 2017, the Company entered into a collaboration and license agreement with Novartis (as amended, the “Collaboration Agreement”) for the research, development, manufacturing and commercialization of products using the Company’s gene-editing technology for the treatment of certain ophthalmic targets and sickle cell disease. In February 2019, Novartis elected to discontinue the sickle cell disease program under the Collaboration Agreement effective in August 2019. In May 2020, Novartis confirmed an ophthalmic target for a therapeutic editing program. Additionally, in accordance with the terms of the Collaboration Agreement, Novartis’ right to substitute other ophthalmic targets expired. For additional information on the Collaboration Agreement, please refer to Note 17. Under the terms of the Collaboration Agreement, the Company granted Novartis a research license, a development and commercialization license, and a manufacturing license, under certain of its intellectual property rights to research, develop, manufacture and commercialize ophthalmic targets. Upon entering into the Collaboration Agreement in November 2017, the Company received an upfront, nonrefundable payment of $35.0 million and issued additional shares of its Series B preferred stock to Novartis for consideration of $10.0 million, in addition to the $5.0 million of Series B preferred stock Novartis had purchased in July 2017. The Company recorded the November 2017 issuance of Series B preferred stock at its estimated fair value of $11.7 million, including $1.7 million of the upfront payment, and allocated the remaining $33.3 million of the upfront payment to the Collaboration Agreement. The Collaboration Agreement consists of a research term, where the Company and Novartis were collaborating to perform research and conduct preclinical development to identify candidates that modulate ophthalmic targets. The Collaboration Agreement also includes exploratory work on the applicability of the gene editing technology with respect to other gene targets. The Company’s obligation to perform such exploratory research was extended pursuant an amendment to the Collaboration Agreement was set to conclude in May 2021. The Company was responsible for the manufacturing of proprietary research grade human hematopoietic stem cell derived adeno-associated virus vectors (“AAVHSCs”) during the research term. Novartis agreed to reimburse research activities performed by the Company at a full-time equivalent rate (“FTE”) and manufacturing activities at cost, up to a maximum of $17.0 million during the research term, as specified and defined in the Collaboration Agreement. Novartis agreed to pay the Company a target fee of $5.0 million if the target meets certain success criteria during the research term (the “target fee trigger date”). The research term was to continue for five years from the effective date of the Collaboration Agreement. Pursuant to the Collaboration Agreement, the Company also agreed to participate on a joint steering committee and a joint manufacturing subcommittee, with equal representation from both the Company and Novartis. Novartis had the exclusive right to develop and commercialize one ophthalmic candidate or product arising from the research activities. Subject to certain limitations pursuant to the terms of the Collaboration Agreement, Novartis agreed to fund all development and commercialization costs. The Company was responsible for manufacturing candidates and products for Novartis during the development and commercialization terms. The Company’s manufacturing activities were to be reimbursed at cost during the development term and at cost plus a margin during the commercialization term, as defined in the Collaboration Agreement. If the Company was not able to manufacture candidates or products that met the quality or quantity requirements of Novartis, then Novartis would have had the right to designate a third-party contract manufacturer or manufacture such candidates or products itself. In accordance with the Collaboration Agreement, taking into consideration Novartis’ election to discontinue the sickle cell disease program, and the expiration of Novartis’ rights to make substitutions of an ophthalmic target, the Company was also eligible to receive up to a total of $265.0 million in milestone payments, including up to $90.0 million in development milestone payments, up to $85.0 million in regulatory milestone payments and up to $90.0 million in commercial milestone payments, with respect to the licensed products. The Company was also eligible to earn tiered royalties on net sales of licensed products by Novartis, its affiliates or sublicensees, ranging from mid-single-digit, to sub-teen double-digit percentages, and such royalties were potentially subject to various reductions and offsets. If any of the exploratory research efforts were advanced into formal research and development programs, the parties agreed to negotiate the economics including potential milestone payments for such programs at that time. Revenue Recognition The Company determined that the (1) research, development and commercialization and manufacturing licenses, (2) the research activities performed by the Company (3) service on the joint committees and (4) manufacturing during the research and development terms represented a single performance obligation under the Collaboration Agreement. Since the option for Novartis to obtain manufacturing during the commercialization term from the Company is at a price that would reflect the standalone selling price, the option does not provide Novartis with a material right and is therefore not a performance obligation under the contract. The Company has concluded that the research, development and commercialization and manufacturing licenses are not distinct from the research activities and manufacturing during the research and development term as Novartis cannot benefit from the licenses without the Company performing the research and manufacturing services. These services are so specialized and rely on the Company’s expertise in gene editing technologies not available in the marketplace. As a result, these licenses have been combined with the research activities, service on the joint committees and the manufacturing during the research and development terms as a single performance obligation. The transaction price consists of the $33.3 million non-refundable upfront payment, net of amounts classified as equity, and projected reimbursable research and manufacturing activities, which have been estimated using the expected value method. None of the target fees or development and regulatory milestone payments have been included in the transaction price, as all are fully constrained. As part of the evaluation of the constraint, the Company considered numerous factors, including the fact that achievement of the milestones is outside of the Company’s control and is contingent upon the success of the Company’s preclinical studies, clinical trials, Novartis’ efforts and the receipt of regulatory approval. In addition, the Company has determined that the commercial milestones and sales-based royalties will be recognized when the related sales occur as they were determined to relate predominately to the licenses transferred to Novartis, and therefore have also been excluded from the transaction price. The Company will re-evaluate the transaction price, including estimated variable consideration included in the transaction price and all constrained amounts, in each reporting period and as uncertain events are resolved or other changes in circumstances occur. The Company identified only one performance obligation in the Collaboration Agreement. Therefore, the Company allocated the transaction price at the onset of the contract to the single performance obligation. The Company recognizes revenue over time using a cost-to-cost method, which it believes best depicts the transfer of control to the customer. Under the cost-to-cost method, the extent of progress towards completion is measured based on the ratio of actual costs incurred to the total estimated costs expected upon satisfying the identified performance obligation. Under this method, revenue is recorded over the performance period as a percentage of the estimated transaction price based on the extent of progress towards completion. As of December 31, 2020, the aggregate amount of the transaction price related to the unsatisfied portion of the performance obligation is $30.2 million, and the Company will recognize this revenue as the research and manufacturing activities are performed, which was expected to occur over a period of time that was estimated to conclude in 2027. In estimating the total costs to satisfy its single performance obligation pursuant to the Novartis agreement, the Company is required to make significant estimates including the expected time it will take to fulfill the performance obligation, which, as of December 31, 2020, was expected to be approximately ten years from the date the Collaboration Agreement was entered into, and the expected costs associated with manufacturing during the research and development terms for a novel manufacturing process as well as the probability of success of a target to move into the development phase. The Company has made estimates of such costs utilizing its experience with similar product candidates, however not identical to those in the Collaboration Agreement. In making such estimates, significant judgment is required to evaluate those key assumptions related to cost estimates. The cumulative effect of revisions to the total estimated costs to complete the Company’s single performance obligation will be recorded in the period in which the changes are identified and amounts can be reasonably estimated. While such revisions will have no impact on the Company’s reported cash flows, a significant change in these assumptions and estimates could have a material impact on the timing and amount of revenue recognized in future periods. During the years ended December 31, 2020 and 2019, the Company recognized revenue under the Collaboration Agreement of $2.3 million and $1.7 million, respectively, of which $0.8 million and $0.6 million was included in deferred revenue at the beginning of each such period. As of December 31, 2020 and 2019, there was approximately $30.2 million and $31.0 million of deferred revenue related to the Collaboration Agreement, respectively. In addition, as of December 31, 2020 and 2019, the Company has recorded accounts receivable of $0.4 million, related to reimbursable research and development costs under the Collaboration Agreement, which are included in prepaid expenses and other current assets on the consolidated balance sheets.

Collaboration and License Agreement

12 Months Ended

Dec. 31, 2020

Organization Consolidation And Presentation Of Financial Statements [Abstract]

15. COLLABORATION AND LICENSE AGREEMENT

Summary of Agreement

In November 2017, the Company entered into a collaboration and license agreement with Novartis (as amended, the “Collaboration Agreement”) for the research, development, manufacturing and commercialization of products using the Company’s gene-editing technology for the treatment of certain ophthalmic targets and sickle cell disease. In February 2019, Novartis elected to discontinue the sickle cell disease program under the Collaboration Agreement effective in August 2019. In May 2020, Novartis confirmed an ophthalmic target for a therapeutic editing program. Additionally, in accordance with the terms of the Collaboration Agreement, Novartis’ right to substitute other ophthalmic targets expired. For additional information on the Collaboration Agreement, please refer to Note 17.

Under the terms of the Collaboration Agreement, the Company granted Novartis a research license, a development and commercialization license, and a manufacturing license, under certain of its intellectual property rights to research, develop, manufacture and commercialize ophthalmic targets. Upon entering into the Collaboration Agreement in November 2017, the Company received an upfront, nonrefundable payment of $35.0 million and issued additional shares of its Series B preferred stock to Novartis for consideration of $10.0 million, in addition to the $5.0 million of Series B preferred stock Novartis had purchased in July 2017. The Company recorded the November 2017 issuance of Series B preferred stock at its estimated fair value of $11.7 million, including $1.7 million of the upfront payment, and allocated the remaining $33.3 million of the upfront payment to the Collaboration Agreement.

The Collaboration Agreement consists of a research term, where the Company and Novartis were collaborating to perform research and conduct preclinical development to identify candidates that modulate ophthalmic targets. The Collaboration Agreement also includes exploratory work on the applicability of the gene editing technology with respect to other gene targets. The Company’s obligation to perform such exploratory research was extended pursuant an amendment to the Collaboration Agreement was set to conclude in May 2021. The Company was responsible for the manufacturing of proprietary research grade human hematopoietic stem cell derived adeno-associated virus vectors (“AAVHSCs”) during the research term. Novartis agreed to reimburse research activities performed by the Company at a full-time equivalent rate (“FTE”) and manufacturing activities at cost, up to a maximum of $17.0 million during the research term, as specified and defined in the Collaboration Agreement. Novartis agreed to pay the Company a target fee of $5.0 million if the target meets certain success criteria during the research term (the “target fee trigger date”). The research term was to continue for five years from the effective date of the Collaboration Agreement. Pursuant to the Collaboration Agreement, the Company also agreed to participate on a joint steering committee and a joint manufacturing subcommittee, with equal representation from both the Company and Novartis.

Novartis had the exclusive right to develop and commercialize one ophthalmic candidate or product arising from the research activities. Subject to certain limitations pursuant to the terms of the Collaboration Agreement, Novartis agreed to fund all development and commercialization costs. The Company was responsible for manufacturing candidates and products for Novartis during the development and commercialization terms. The Company’s manufacturing activities were to be reimbursed at cost during the development term and at cost plus a margin during the commercialization term, as defined in the Collaboration Agreement. If the Company was not able to manufacture candidates or products that met the quality or quantity requirements of Novartis, then Novartis would have had the right to designate a third-party contract manufacturer or manufacture such candidates or products itself.

In accordance with the Collaboration Agreement, taking into consideration Novartis’ election to discontinue the sickle cell disease program, and the expiration of Novartis’ rights to make substitutions of an ophthalmic target, the Company was also eligible to receive up to a total of $265.0 million in milestone payments, including up to $90.0 million in development milestone payments, up to $85.0 million in regulatory milestone payments and up to $90.0 million in commercial milestone payments, with respect to the licensed products. The Company was also eligible to earn tiered royalties on net sales of licensed products by Novartis, its affiliates or sublicensees, ranging from mid-single-digit, to sub-teen double-digit percentages, and such royalties were potentially subject to various reductions and offsets. If any of the exploratory research efforts were advanced into formal research and development programs, the parties agreed to negotiate the economics including potential milestone payments for such programs at that time.

Revenue Recognition

The Company determined that the (1) research, development and commercialization and manufacturing licenses, (2) the research activities performed by the Company (3) service on the joint committees and (4) manufacturing during the research and development terms represented a single performance obligation under the Collaboration Agreement. Since the option for Novartis to obtain manufacturing during the commercialization term from the Company is at a price that would reflect the standalone selling price, the option does not provide Novartis with a material right and is therefore not a performance obligation under the contract.

The Company has concluded that the research, development and commercialization and manufacturing licenses are not distinct from the research activities and manufacturing during the research and development term as Novartis cannot benefit from the licenses without the Company performing the research and manufacturing services. These services are so specialized and rely on the Company’s expertise in gene editing technologies not available in the marketplace. As a result, these licenses have been combined with the research activities, service on the joint committees and the manufacturing during the research and development terms as a single performance obligation.

The transaction price consists of the $33.3 million non-refundable upfront payment, net of amounts classified as equity, and projected reimbursable research and manufacturing activities, which have been estimated using the expected value method. None of the target fees or development and regulatory milestone payments have been included in the transaction price, as all are fully constrained. As part of the evaluation of the constraint, the Company considered numerous factors, including the fact that achievement of the milestones is outside of the Company’s control and is contingent upon the success of the Company’s preclinical studies, clinical trials, Novartis’ efforts and the receipt of regulatory approval. In addition, the Company has determined that the commercial milestones and sales-based royalties will be recognized when the related sales occur as they were determined to relate predominately to the licenses transferred to Novartis, and therefore have also been excluded from the transaction price. The Company will re-evaluate the transaction price, including estimated variable consideration included in the transaction price and all constrained amounts, in each reporting period and as uncertain events are resolved or other changes in circumstances occur.

The Company identified only one performance obligation in the Collaboration Agreement. Therefore, the Company allocated the transaction price at the onset of the contract to the single performance obligation.

The Company recognizes revenue over time using a cost-to-cost method, which it believes best depicts the transfer of control to the customer. Under the cost-to-cost method, the extent of progress towards completion is measured based on the ratio of actual costs incurred to the total estimated costs expected upon satisfying the identified performance obligation. Under this method, revenue is recorded over the performance period as a percentage of the estimated transaction price based on the extent of progress towards completion. As of December 31, 2020, the aggregate amount of the transaction price related to the unsatisfied portion of the performance obligation is $30.2 million, and the Company will recognize this revenue as the research and manufacturing activities are performed, which was expected to occur over a period of time that was estimated to conclude in 2027.

In estimating the total costs to satisfy its single performance obligation pursuant to the Novartis agreement, the Company is required to make significant estimates including the expected time it will take to fulfill the performance obligation, which, as of December 31, 2020, was expected to be approximately ten years from the date the Collaboration Agreement was entered into, and the expected costs associated with manufacturing during the research and development terms for a novel manufacturing process as well as the probability of success of a target to move into the development phase. The Company has made estimates of such costs utilizing its experience with similar product candidates, however not identical to those in the Collaboration Agreement. In making such estimates, significant judgment is required to evaluate those key assumptions related to cost estimates. The cumulative effect of revisions to the total estimated costs to complete the Company’s single performance obligation will be recorded in the period in which the changes are identified and amounts can be reasonably estimated. While such revisions will have no impact on the Company’s reported cash flows, a significant change in these assumptions and estimates could have a material impact on the timing and amount of revenue recognized in future periods.

During the years ended December 31, 2020 and 2019, the Company recognized revenue under the Collaboration Agreement of $2.3 million and $1.7 million, respectively, of which $0.8 million and $0.6 million was included in deferred revenue at the beginning of each such period. As of December 31, 2020 and 2019, there was approximately $30.2 million and $31.0 million of deferred revenue related to the Collaboration Agreement, respectively. In addition, as of December 31, 2020 and 2019, the Company has recorded accounts receivable of $0.4 million, related to reimbursable research and development costs under the Collaboration Agreement, which are included in prepaid expenses and other current assets on the consolidated balance sheets.