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 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. On February 26, 2021, Homology received notice from Novartis that they had elected to terminate the Collaboration Agreement with the Company with respect to the remaining ophthalmic target under the Collaboration Agreement and as a result, the Company regained worldwide exclusive rights to this target. Accordingly, the notice served as notice of Novartis’ termination of the Collaboration Agreement in its entirety, which became effective on August 26, 2021. Under the terms of the Collaboration Agreement, Novartis was obligated to continue to reimburse the Company for certain research and development costs through August 26, 2021. Upon effectiveness of the termination, such reimbursements ceased. The Company recognized revenue under the Collaboration Agreement over time using a cost-to-cost method, which it believed best depicted the transfer of control to the customer. The delivery of the termination notice caused a change in the estimate of total costs to satisfy the single performance obligation under the Collaboration Agreement. The cumulative effect of revisions to the total estimated costs to complete the Company’s single performance obligation was recorded in the current period when the changes were identified and amounts could be reasonably estimated. As such, the Company recognized a cumulative effect adjustment of approximately $26.9 million in collaboration revenue during the year ended December 31, 2021. During the years ended December 31, 2021 and 2020, the Company recognized revenue under the Collaboration Agreement of $30.8 million and $2.3 million, respectively, of which $30.2 million and $0.8 million was included in deferred revenue at the beginning of each such period, respectively. As of December 31, 2021 and 2020, there was no deferred revenue and approximately $30.2 million of deferred revenue related to the Collaboration Agreement, respectively. In addition, as of December 31, 2021 and 2020, the Company recorded no accounts receivable and $0.4 million, respectively, 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. As of December 31, 2021, all deferred revenue under the Collaboration Agreement has been recognized and there are no further obligations due to Novartis.

Collaboration and License Agreement

12 Months Ended

Dec. 31, 2020

Organization, Consolidation and Presentation of Financial Statements [Abstract]

15. COLLABORATION AND LICENSE 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. On February 26, 2021, Homology received notice from Novartis that they had elected to terminate the Collaboration Agreement with the Company with respect to the remaining ophthalmic target under the Collaboration Agreement and as a result, the Company regained worldwide exclusive rights to this target. Accordingly, the notice served as notice of Novartis’ termination of the Collaboration Agreement in its entirety, which became effective on August 26, 2021. Under the terms of the Collaboration Agreement, Novartis was obligated to continue to reimburse the Company for certain research and development costs through August 26, 2021. Upon effectiveness of the termination, such reimbursements ceased.

The Company recognized revenue under the Collaboration Agreement over time using a cost-to-cost method, which it believed best depicted the transfer of control to the customer. The delivery of the termination notice caused a change in the estimate of total costs to satisfy the single performance obligation under the Collaboration Agreement. The cumulative effect of revisions to the total estimated costs to complete the Company’s single performance obligation was recorded in the current period when the changes were identified and amounts could be reasonably estimated. As such, the Company recognized a cumulative effect adjustment of approximately $26.9 million in collaboration revenue during the year ended December 31, 2021.

During the years ended December 31, 2021 and 2020, the Company recognized revenue under the Collaboration Agreement of $30.8 million and $2.3 million, respectively, of which $30.2 million and $0.8 million was included in deferred revenue at the beginning of each such period, respectively. As of December 31, 2021 and 2020, there was no deferred revenue and approximately $30.2 million of deferred revenue related to the Collaboration Agreement, respectively. In addition, as of December 31, 2021 and 2020, the Company recorded no accounts receivable and $0.4 million, respectively, 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.

As of December 31, 2021, all deferred revenue under the Collaboration Agreement has been recognized and there are no further obligations due to Novartis.