LICENSE AND COLLABORATION AGREEMENTS	9 Months Ended
Sep. 30, 2021
Organization Consolidation And Presentation Of Financial Statements [Abstract]
LICENSE AND COLLABORATION AGREEMENTS	3. LICENSE AND COLLABORATION AGREEMENTS F. Hoffman-La Roche Ltd. For the three and nine months ended September 30, 2021, the Company recognized $22.5 million and $66.8 million of collaboration revenue, respectively, associated with the license, collaboration and option agreement (the “Roche Agreement”) with F. Hoffman-La Roche Ltd. (“Roche”). For the three and nine months ended September 30, 2020, the Company recognized $22.5 million and $61.7 million, respectively, of collaboration revenue primarily related to the Roche Agreement. As of September 30, 2021, the Company has total deferred revenue of $686.0 million associated with the Roche Agreement, of which $89.2 million is classified as current. The portion of deferred revenue related to the separate material rights for the options to acquire ex-U.S. rights to certain Duchenne-specific programs was $485.0 million as of September 30, 2021. The costs associated with co-development activities performed under the Roche Agreement are included in operating expenses, with any reimbursement of costs by Roche reflected as a reduction of such expenses when the related expense is incurred. For the three and nine months ended September 30, 2021, costs reimbursable by Roche and reflected as a reduction to operating expenses were $29.4 million and $60.8 million, respectively. For the three and nine months ended September 30, 2020, costs reimbursable by Roche and reflected as a reduction to operating expenses were $16.9 million and $42.2 million, respectively. As of September 30, 2021, there was $29.1 million of collaboration receivable included in other current assets. Nationwide Children’s Hospital In December 2016, the Company entered into an exclusive option agreement with Nationwide Children’s Hospital (“Nationwide”) from which the Company obtained an exclusive right to acquire a worldwide license of the micro-dystrophin gene therapy technology for Duchenne and Becker muscular dystrophy. In October 2018, the Company exercised the option and entered into a license agreement with Nationwide, which granted the Company exclusive worldwide rights to develop, manufacture and commercialize a micro-dystrophin gene therapy product candidate. In July 2021, the Company entered into an agreement with Nationwide to settle a dispute relating to a sublicense payment owed by the Company resulting from the upfront payment received from Roche under the Roche Agreement. The total sublicense payment payable to Nationwide under the agreement is $38.0 million, which was paid in July 2021. Approximately $9.3 million of this amount was previously accrued as of December 31, 2020 with the remaining $28.7 million accrued during the three months ended June 30, 2021. The expense relating to this payment is recognized to research and development expense. As a result of this payment, the Company has no further financial obligations to Nationwide resulting from the upfront payment received under the Roche Agreement. BioMarin Pharmaceutical, Inc. The FDA approval of AMONDYS 45 (casimersen) in February 2021 resulted in a settlement charge to BioMarin Pharmaceutical, Inc. (“BioMarin”) of $10.0 million under the terms of the previous settlement agreement with BioMarin. This amount, which was expensed to operations as incurred, is separately presented as settlement and license charges in the Company’s unaudited condensed consolidated statement of operations and comprehensive loss for the nine months ended September 30, 2021. Research and Option Agreements The Company has research and option agreements with third parties in order to develop various technologies and biologics that may be used in the administration of the Company’s genetic therapeutics. The agreements generally provide for research services related to pre-clinical development programs, and options to license the technology for clinical development. Prior to the options under these agreements being executed, the Company may be required to make up to $11.0 million in research milestone payments. Under these agreements, there are $242.0 million in potential option payments to be made by the Company upon the determination to exercise the options. Additionally, if the options for each agreement are executed, the Company would incur additional contingent obligations and may be required to make development, regulatory, and sales milestone payments and tiered royalty payments based on the sales of the developed products upon commercialization. For the nine months ended September 30, 2021, the Company recognized $3.0 million of research milestone expenses, with no similar activity for the nine months ended September 30, 2020. As of September 30, 2021, the Company has not exercised any options nor have any additional research milestone payments become probable of occurring. Milestone Obligations The Company has license and collaboration agreements in place for which it could be obligated to pay, in addition to the payment of up-front fees upon execution of the agreements, certain milestone payments as a product candidate proceeds from the submission of an investigational new drug application through approval for commercial sale and beyond. As of September 30, 2021, the Company may be obligated to make up to $4.1 billion in future development, regulatory, commercial and up-front royalty milestone payments associated with its license and collaboration agreements. These obligations exclude potential future option and milestone payments for options that have yet to be exercised within agreements entered into by the Company as of September 30, 2021, which are discussed above. For the three and nine months ended September 30, 2021, the Company recognized up-front, development milestone, settlement and other expenses of $4.5 million and $50.2 million, respectively, as research and development expense in the accompanying unaudited condensed consolidated statement of operations and comprehensive loss, inclusive of the expenses discussed above. For the three and nine months ended September 30, 2020, the Company recognized up-front, development milestone, and other expenses of $15.4 million and $36.7 million, respectively, as research and development expense in the accompanying unaudited condensed consolidated statement of operations and comprehensive loss.

LICENSE AND COLLABORATION AGREEMENTS

9 Months Ended

Sep. 30, 2021

Organization Consolidation And Presentation Of Financial Statements [Abstract]

3. LICENSE AND COLLABORATION AGREEMENTS

F. Hoffman-La Roche Ltd.

For the three and nine months ended September 30, 2021, the Company recognized $22.5 million and $66.8 million of collaboration revenue, respectively, associated with the license, collaboration and option agreement (the “Roche Agreement”) with F. Hoffman-La Roche Ltd. (“Roche”). For the three and nine months ended September 30, 2020, the Company recognized $22.5 million and $61.7 million, respectively, of collaboration revenue primarily related to the Roche Agreement. As of September 30, 2021, the Company has total deferred revenue of $686.0 million associated with the Roche Agreement, of which $89.2 million is classified as current. The portion of deferred revenue related to the separate material rights for the options to acquire ex-U.S. rights to certain Duchenne-specific programs was $485.0 million as of September 30, 2021.

The costs associated with co-development activities performed under the Roche Agreement are included in operating expenses, with any reimbursement of costs by Roche reflected as a reduction of such expenses when the related expense is incurred. For the three and nine months ended September 30, 2021, costs reimbursable by Roche and reflected as a reduction to operating expenses were $29.4 million and $60.8 million, respectively. For the three and nine months ended September 30, 2020, costs reimbursable by Roche and reflected as a reduction to operating expenses were $16.9 million and $42.2 million, respectively. As of September 30, 2021, there was $29.1 million of collaboration receivable included in other current assets.

Nationwide Children’s Hospital

In December 2016, the Company entered into an exclusive option agreement with Nationwide Children’s Hospital (“Nationwide”) from which the Company obtained an exclusive right to acquire a worldwide license of the micro-dystrophin gene therapy technology for Duchenne and Becker muscular dystrophy. In October 2018, the Company exercised the option and entered into a license agreement with Nationwide, which granted the Company exclusive worldwide rights to develop, manufacture and commercialize a micro-dystrophin gene therapy product candidate. In July 2021, the Company entered into an agreement with Nationwide to settle a dispute relating to a sublicense payment owed by the Company resulting from the upfront payment received from Roche under the Roche Agreement. The total sublicense payment payable to Nationwide under the agreement is $38.0 million, which was paid in July 2021. Approximately $9.3 million of this amount was previously accrued as of December 31, 2020 with the remaining $28.7 million accrued during the three months ended June 30, 2021. The expense relating to this payment is recognized to research and development expense. As a result of this payment, the Company has no further financial obligations to Nationwide resulting from the upfront payment received under the Roche Agreement.

BioMarin Pharmaceutical, Inc.

The FDA approval of AMONDYS 45 (casimersen) in February 2021 resulted in a settlement charge to BioMarin Pharmaceutical, Inc. (“BioMarin”) of $10.0 million under the terms of the previous settlement agreement with BioMarin. This amount, which was expensed to operations as incurred, is separately presented as settlement and license charges in the Company’s unaudited condensed consolidated statement of operations and comprehensive loss for the nine months ended September 30, 2021.

Research and Option Agreements

The Company has research and option agreements with third parties in order to develop various technologies and biologics that may be used in the administration of the Company’s genetic therapeutics. The agreements generally provide for research services related to pre-clinical development programs, and options to license the technology for clinical development. Prior to the options under these agreements being executed, the Company may be required to make up to $11.0 million in research milestone payments. Under these agreements, there are $242.0 million in potential option payments to be made by the Company upon the determination to exercise the options. Additionally, if the options for each agreement are executed, the Company would incur additional contingent obligations and may be required to make development, regulatory, and sales milestone payments and tiered royalty payments based on the sales of the developed products upon commercialization. For the nine months ended September 30, 2021, the Company recognized $3.0 million of research milestone expenses, with no similar activity for the nine months ended September 30, 2020. As of September 30, 2021, the Company has not exercised any options nor have any additional research milestone payments become probable of occurring.

Milestone Obligations

The Company has license and collaboration agreements in place for which it could be obligated to pay, in addition to the payment of up-front fees upon execution of the agreements, certain milestone payments as a product candidate proceeds from the submission of an investigational new drug application through approval for commercial sale and beyond. As of September 30, 2021, the Company may be obligated to make up to $4.1 billion in future development, regulatory, commercial and up-front royalty milestone payments associated with its license and collaboration agreements. These obligations exclude potential future option and milestone payments for options that have yet to be exercised within agreements entered into by the Company as of September 30, 2021, which are discussed above. For the three and nine months ended September 30, 2021, the Company recognized up-front,

development milestone, settlement and other expenses of $4.5 million and $50.2 million, respectively, as research and development expense in the accompanying unaudited condensed consolidated statement of operations and comprehensive loss, inclusive of the expenses discussed above. For the three and nine months ended September 30, 2020, the Company recognized up-front, development milestone, and other expenses of $15.4 million and $36.7 million, respectively, as research and development expense in the accompanying unaudited condensed consolidated statement of operations and comprehensive loss.