Commitments and Contingencies	9 Months Ended
Sep. 30, 2021
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	6. Commitments and Contingencies Litigation There have been no material changes to any of the outstanding litigation, nor is the Company a party to any new litigation, since December 31, 2020, except as described below. For further information please see the notes to the consolidated financial statements included in the Company’s Annual Report for the year ended December 31, 2020. Caribou Arbitration On October 17, 2018, the Company initiated an arbitration proceeding against Caribou Biosciences, Inc. (“Caribou”) asserting that Caribou violated the terms and conditions of a license agreement the Company entered into with them in July 2014 related to certain IP (the “Caribou License”), as well as other contractual and legal obligations to the Company, by using and seeking to license to third parties two patent families relating to specific structural or chemical modifications of guide RNAs (“gRNAs”), that were purportedly invented or controlled by Caribou, in the Company’s exclusive human therapeutic field, before an agreed-upon cutoff date of January 30, 2018. On September 26, 2019, the Company announced that the arbitration panel issued an interim award concluding that both the structural and chemical gRNA modification technologies were exclusively licensed to the Company by Caribou pursuant to the Caribou License. Nevertheless, the arbitration panel, solely with respect to the clinically modified gRNAs, stated that it will declare that Caribou has an equitable “leaseback”, which it described as exclusive, perpetual and worldwide (the “Caribou Award”). The Caribou Award does not include the structural guide modifications IP also at issue in the arbitration, any other IP exclusively licensed or sublicensed by Caribou to the Company under the Caribou License (including but not limited to the foundational CRISPR/Cas9 IP co-owned by the Regents of the University of California, University of Vienna and Dr. Emmanuelle Charpentier), or any other of the Company’s IP. On February 6, 2020, the panel clarified that the Caribou Award is limited to a particular on-going Caribou program, known as CB-010, which seeks to develop a CAR-T product directed at CD19. On June 16, 2021, the Company executed a Leaseback Agreement (“Leaseback”) with Caribou, which settled the ongoing arbitration. Under the Leaseback negotiated by the parties, in exchange for an upfront payment, potential future regulatory and sales milestones, and single-digit royalties payable by Caribou, the Company has agreed to leaseback or sublicense certain CRISPR/Cas9 IP, including the Company’s chemical gRNA modification technology and foundational CRISPR/Cas9 IP, to Caribou so that it can develop and commercialize CB-010. Caribou also will be responsible for any payments required in respect of the Company’s in-licensed IP. The Company recorded $1.0 million within “Collaboration Revenue” in the second quarter of 2021 on the condensed consolidated statements of operations and comprehensive loss for an upfront payment related to the Leaseback and received the payment in the third quarter of 2021. License Agreements The Company is party to license agreements, which include contingent payments. These payments will become payable if and when certain development, regulatory and commercial milestones are achieved. As of September 30, 2021, the satisfaction and timing of the contingent payments is uncertain and not reasonably estimable.

Commitments and Contingencies

9 Months Ended

Sep. 30, 2021

Commitments And Contingencies Disclosure [Abstract]

6. Commitments and Contingencies

Litigation

There have been no material changes to any of the outstanding litigation, nor is the Company a party to any new litigation, since December 31, 2020, except as described below. For further information please see the notes to the consolidated financial statements included in the Company’s Annual Report for the year ended December 31, 2020.

Caribou Arbitration

On October 17, 2018, the Company initiated an arbitration proceeding against Caribou Biosciences, Inc. (“Caribou”) asserting that Caribou violated the terms and conditions of a license agreement the Company entered into with them in July 2014 related to certain IP (the “Caribou License”), as well as other contractual and legal obligations to the Company, by using and seeking to license to third parties two patent families relating to specific structural or chemical modifications of guide RNAs (“gRNAs”), that were purportedly invented or controlled by Caribou, in the Company’s exclusive human therapeutic field, before an agreed-upon cutoff date of January 30, 2018.

On September 26, 2019, the Company announced that the arbitration panel issued an interim award concluding that both the structural and chemical gRNA modification technologies were exclusively licensed to the Company by Caribou pursuant to the Caribou License. Nevertheless, the arbitration panel, solely with respect to the clinically modified gRNAs, stated that it will declare that Caribou has an equitable “leaseback”, which it described as exclusive, perpetual and worldwide (the “Caribou Award”). The Caribou Award does not include the structural guide modifications IP also at issue in the arbitration, any other IP exclusively licensed or sublicensed by Caribou to the Company under the Caribou License (including but not limited to the foundational CRISPR/Cas9 IP co-owned by the Regents of the University of California, University of Vienna and Dr. Emmanuelle Charpentier), or any other of the Company’s IP. On February 6, 2020, the panel clarified that the Caribou Award is limited to a particular on-going Caribou program, known as CB-010, which seeks to develop a CAR-T product directed at CD19.

On June 16, 2021, the Company executed a Leaseback Agreement (“Leaseback”) with Caribou, which settled the ongoing arbitration. Under the Leaseback negotiated by the parties, in exchange for an upfront payment, potential future regulatory and sales milestones, and single-digit royalties payable by Caribou, the Company has agreed to leaseback or sublicense certain CRISPR/Cas9 IP, including the Company’s chemical gRNA modification technology and foundational CRISPR/Cas9 IP, to Caribou so that it can develop and commercialize CB-010. Caribou also will be responsible for any payments required in respect of the Company’s in-licensed IP. The Company recorded $1.0 million within “Collaboration Revenue” in the second quarter of 2021 on the condensed consolidated statements of operations and comprehensive loss for an upfront payment related to the Leaseback and received the payment in the third quarter of 2021.

License Agreements

The Company is party to license agreements, which include contingent payments. These payments will become payable if and when certain development, regulatory and commercial milestones are achieved. As of September 30, 2021, the satisfaction and timing of the contingent payments is uncertain and not reasonably estimable.