Subsequent Events	3 Months Ended
Mar. 31, 2021
Subsequent Events [Abstract]
Subsequent Events	12. Subsequent Events As described in Note 7, in December 2017, the Company and Vertex entered into the JDA pursuant to which the parties agreed to, among other things, co-develop and co-commercialize CTX001 and other product candidates specified in the JDA. On April 16, 2021, the Company and Vertex agreed to amend and restate the JDA and entered into an Amended and Restated Joint Development and Commercialization Agreement (the “A&R JDCA”), 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; (b) adjust the allocation of net profits and net losses between the parties with respect to CTX001 only; 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 CTX001) that may be researched, developed, manufactured and commercialized under such agreement. The A&R JDCA includes, among other things, provisions relating to the following: Governance; Activities. The Company and Vertex will establish the following committees: (i) a joint oversight committee to provide high-level oversight and (ii) a transition committee to provide for forum planning, discussing and sharing information regarding certain transition activities until completion of such activities. Effective as of the closing of the transaction contemplated by the A&R JDCA, the previously established collaboration strategy team and all working groups established by such team will be disbanded. Each of the committees will contain an equal number of representatives from each of the Company and Vertex. The A&R JDCA provides that, subject to the terms and conditions of such agreement, Vertex will have the right to conduct all research, development, manufacturing and commercialization activities relating to the specified product candidates and products (including CTX001) throughout the world subject to the Company’s reserved right to conduct certain activities. The Company continues to participate in certain aspects of such activities in an observer capacity unless and to the extent otherwise agreed to by the parties. Financial Terms. In connection with the closing of the transaction contemplated by the A&R JDCA, the Company will receive a $900 million up-front payment from Vertex and a one-time $200 million milestone payment upon receipt by Vertex of the first marketing approval of the initial product candidate from the U.S. Food and Drug Administration or the European Commission. The net profits and net losses, as applicable, incurred under the A&R JDCA with respect to all product candidates and products specified in the A&R JDCA other than CTX001 shall be shared equally between the Company and Vertex. With respect to CTX001 only, the net profits and net losses, as applicable, incurred under the A&R JDCA through July 1, 2021 (or such applicable later date in the event HSR clearance has not been received by October 1, 2021) in connection with the initial shared product (i.e., CTX001) will be shared equally between the Company and Vertex, and beginning July 1, 2021 (or such applicable later date in the event HSR clearance has not been received by October 1, 2021), the net profits and net losses, as applicable, incurred under the A&R JDCA will be allocated 40% to the Company and 60% to Vertex. Termination. Either party can terminate the A&R JDCA upon the other party’s material breach, subject to specified notice and cure provisions, or, in the case of Vertex, in the event that the Company becomes subject to specified bankruptcy, winding up or similar circumstances. Either party may terminate the A&R JDCA in the event the other party commences or participates in any action or proceeding challenging the validity or enforceability of any patent that is licensed to such challenging party pursuant to the A&R JDCA. Vertex also has the right to terminate the A&R JDCA for convenience at any time after giving prior written notice. If circumstances arise pursuant to which a party would have the right to terminate the A&R JDCA on account of an uncured material breach, such party may elect to keep the A&R JDCA in effect and cause such breaching party to be treated as if it had exercised its opt-out rights with respect to the products associated with such uncured material breach (described below) and the royalties payable to the breaching party would be reduced by a specified percentage. Opt-Out Rights. Either party may opt out of the development of a product candidate under the A&R JDCA after predetermined points in the development of the product candidate, on a candidate-by-candidate basis. In the event of such opt-out, the party opting-out will no longer share in the net profits and net losses associated with such product candidate and, instead, the opting-out party will be entitled to high single to mid-teen percentage royalties on the net sales of such product, if commercialized. The closing of the transaction contemplated by the A&R JDCA is subject to certain conditions including the expiration of the waiting period under the Hart-Scott-Rodino Antitrust Improvements Act and any other required antitrust clearance.

Subsequent Events

3 Months Ended

Mar. 31, 2021

12. Subsequent Events

As described in Note 7, in December 2017, the Company and Vertex entered into the JDA pursuant to which the parties agreed to, among other things, co-develop and co-commercialize CTX001 and other product candidates specified in the JDA.

On April 16, 2021, the Company and Vertex agreed to amend and restate the JDA and entered into an Amended and Restated Joint Development and Commercialization Agreement (the “A&R JDCA”), 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; (b) adjust the allocation of net profits and net losses between the parties with respect to CTX001 only; 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 CTX001) that may be researched, developed, manufactured and commercialized under such agreement.

The A&R JDCA includes, among other things, provisions relating to the following:

Governance; Activities. The Company and Vertex will establish the following committees: (i) a joint oversight committee to provide high-level oversight and (ii) a transition committee to provide for forum planning, discussing and sharing information regarding certain transition activities until completion of such activities. Effective as of the closing of the transaction contemplated by the A&R JDCA, the previously established collaboration strategy team and all working groups established by such team will be disbanded. Each of the committees will contain an equal number of representatives from each of the Company and Vertex. The A&R JDCA provides that, subject to the terms and conditions of such agreement, Vertex will have the right to conduct all research, development, manufacturing and commercialization activities relating to the specified product candidates and products (including CTX001) throughout the world subject to the Company’s reserved right to conduct certain activities. The Company continues to participate in certain aspects of such activities in an observer capacity unless and to the extent otherwise agreed to by the parties.

Financial Terms. In connection with the closing of the transaction contemplated by the A&R JDCA, the Company will receive a $900 million up-front payment from Vertex and a one-time $200 million milestone payment upon receipt by Vertex of the first marketing approval of the initial product candidate from the U.S. Food and Drug Administration or the European Commission. The net profits and net losses, as applicable, incurred under the A&R JDCA with respect to all product candidates and products specified in the A&R JDCA other than CTX001 shall be shared equally between the Company and Vertex. With respect to CTX001 only, the net profits and net losses, as applicable, incurred under the A&R JDCA through July 1, 2021 (or such applicable later date in the event HSR clearance has not been received by October 1, 2021) in connection with the initial shared product (i.e., CTX001) will be shared equally between the Company and Vertex, and beginning July 1, 2021 (or such applicable later date in the event HSR clearance has not been received by October 1, 2021), the net profits and net losses, as applicable, incurred under the A&R JDCA will be allocated 40% to the Company and 60% to Vertex.

Termination. Either party can terminate the A&R JDCA upon the other party’s material breach, subject to specified notice and cure provisions, or, in the case of Vertex, in the event that the Company becomes subject to specified bankruptcy, winding up or similar circumstances. Either party may terminate the A&R JDCA in the event the other party commences or participates in any action or proceeding challenging the validity or enforceability of any patent that is licensed to such challenging party pursuant to the A&R JDCA. Vertex also has the right to terminate the A&R JDCA for convenience at any time after giving prior written notice.

If circumstances arise pursuant to which a party would have the right to terminate the A&R JDCA on account of an uncured material breach, such party may elect to keep the A&R JDCA in effect and cause such breaching party to be treated as if it had exercised its opt-out rights with respect to the products associated with such uncured material breach (described below) and the royalties payable to the breaching party would be reduced by a specified percentage.

Opt-Out Rights. Either party may opt out of the development of a product candidate under the A&R JDCA after predetermined points in the development of the product candidate, on a candidate-by-candidate basis. In the event of such opt-out, the party opting-out will no longer share in the net profits and net losses associated with such product candidate and, instead, the opting-out party will be entitled to high single to mid-teen percentage royalties on the net sales of such product, if commercialized.

The closing of the transaction contemplated by the A&R JDCA is subject to certain conditions including the expiration of the waiting period under the Hart-Scott-Rodino Antitrust Improvements Act and any other required antitrust clearance.