Collaborative Arrangements	12 Months Ended
Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Collaborative Arrangements	Collaborative Arrangements The Company has entered into numerous agreements pursuant to which it collaborates with third parties on research, development and commercialization programs, including in-license and out-license agreements. In-license Agreements The Company has entered into a number of license agreements in order to advance and obtain access to technologies and services related to its research and early-development activities. The Company is generally required to make an upfront payment upon execution of the license agreement; development, regulatory and commercialization milestones payments upon the achievement of certain product research, development and commercialization objectives; and royalty payments on future sales, if any, of commercial products resulting from the collaboration. Pursuant to the terms of its in-license agreements, the Company’s collaborators typically lead the discovery efforts and the Company leads all preclinical, development and commercialization activities associated with the advancement of any drug candidates and funds all expenses. The Company typically can terminate its in-license agreements by providing advance notice to its collaborators; the required length of notice is dependent on whether any product developed under the license agreement has received marketing approval. The Company’s license agreements may be terminated by either party for a material breach by the other, subject to notice and cure provisions. Unless earlier terminated, these license agreements generally remain in effect until the date on which the royalty term and all payment obligations with respect to all products in all countries have expired. CRISPR Therapeutics AG In 2015, the Company entered into a strategic collaboration, option and license agreement (the “CRISPR Agreement”) with CRISPR Therapeutics AG and its affiliates (“CRISPR”) to collaborate on the discovery and development of potential new treatments aimed at the underlying genetic causes of human diseases using CRISPR-Cas9 gene-editing technology. The Company had the exclusive right to license certain targets. In the fourth quarter of 2019, the Company paid an aggregate of $30.0 million to exclusively license three CRISPR-Cas9-based targets, including CF, pursuant to the CRISPR Agreement. The Company recorded the $30.0 million total option payment to “Research and development expenses” in the fourth quarter of 2019. For each of the three targets that the Company elected to license, CRISPR has the potential to receive up to an additional $410.0 million in development, regulatory and commercial milestones as well as royalties on net product sales. In 2017, the Company entered into a co-development and co-commercialization agreement with CRISPR pursuant to the terms of the CRISPR Agreement, under which the Company and CRISPR are co-developing and will co-commercialize CTX001 (the “CTX001 Co-Co Agreement”) for the treatment of hemoglobinopathies, including treatments for sickle cell disease and beta thalassemia. As part of the collaboration, the Company and CRISPR share equally all development costs and potential worldwide revenues related to potential hemoglobinopathy treatments. The Company concluded that the CTX001 Co-Co Agreement is a cost-sharing arrangement, which results in the net impact of the arrangement being recorded in “Research and development expenses” in its consolidated statements of operations. During the years ended December 31, 2020, 2019 and 2018, the net expense related to the CTX001 Co-Co Agreement was $50.6 million, $30.1 million and $19.7 million, respectively. In July 2019, the Company entered into a separate strategic collaboration and license agreement (the “CRISPR DMD/DM1 Agreement”) with CRISPR. Pursuant to this agreement, the Company received an exclusive worldwide license to CRISPR’s existing and future intellectual property for Duchenne muscular dystrophy (“DMD”) and myotonic dystrophy type 1 (“DM1”) and the Company made an upfront payment of $175.0 million to CRISPR. The Company concluded that it did not have any alternative future use for the acquired in-process research and development and recorded the upfront payment to “Research and development expenses” in the third quarter of 2019. In 2020, the Company recorded $25.0 million to “Research and development expenses” related to a pre-clinical milestone earned by CRISPR under the CRISPR DMD/DM1 Agreement. CRISPR has the potential to receive up to an additional $800.0 million in research, development, regulatory and commercial milestones for the DMD and DM1 programs as well as royalties on net product sales. CRISPR has the option to co-develop and co-commercialize all DM1 products globally and forego the milestones and royalties associated with the DM1 program. The Company funds all expenses associated with the collaboration except for research costs for specified guide RNA research conducted by CRISPR, which the Company and CRISPR share equally. Kymera Therapeutics Inc. In May 2019, the Company entered into a strategic research and development collaboration agreement with Kymera Therapeutics Inc. (“Kymera”) to advance small molecule protein degraders against multiple targets. Kymera’s proprietary platform technology is being applied in the collaboration activities in exchange for an upfront payment of $50.0 million. The Company has the exclusive right to license up to six protein targets, for each of which Kymera may receive up to $170.0 million in payments, including development, regulatory and commercial milestones as well as royalties on net product sales. In addition to the upfront payment, the Company purchased $20.0 million of Kymera’s preferred stock. The Company determined that the fair value of its investment in Kymera’s preferred stock, which did not have a readily determinable fair value, approximated $20.0 million. The preferred stock converted to common stock when Kymera became a publicly traded company in 2020. The Company determined that substantially all of the fair value of the Kymera collaboration agreement was attributable to in-process research and development and no substantive processes were acquired that would constitute a business. The Company concluded that it did not have any alternative future use for the acquired in-process research and development and recorded the $50.0 million upfront payment to “Research and development expenses” in 2019. Moderna, Inc. In 2016, the Company entered into a strategic collaboration and licensing agreement with Moderna, Inc. (“Moderna”), pursuant to which the parties are seeking to identify and develop messenger ribonucleic acid (“mRNA”) therapeutics for the treatment of CF. In September 2020, the Company entered into a new strategic collaboration and licensing agreement with Moderna (the “2020 Moderna Agreement”) aimed at the discovery and development of lipid nanoparticles and mRNAs that can deliver gene-editing therapies to lung cells for the treatment of CF. Pursuant to the 2020 Moderna Agreement, Moderna received an upfront payment of $75.0 million and is eligible to receive up to $380.0 million in development, regulatory and commercial milestones as well as royalties on net product sales. The Company determined that substantially all of the fair value of the 2020 Moderna Agreement was attributable to in-process research and development and no substantive processes were acquired that would constitute a business. The Company concluded that it did not have any alternative future use for the acquired in-process research and development and recorded the upfront payment to “Research and development expenses” in the third quarter of 2020. Other In-License Agreements In addition to the collaborative arrangements described above, the Company has entered into additional in-license agreements that it does not consider to be individually significant to its consolidated financial statements. In addition to the payments described above, the Company recorded upfront, option and milestone payments totaling $84.6 million in 2020, $63.3 million in 2019 and $46.9 million in 2018 to “Research and development expenses” which included a $40.0 million upfront payment to Skyhawk Therapeutics, Inc. (“Skyhawk”) in 2020. For Skyhawk and several other in-license agreements that are not individually significant to the Company’s consolidated financial statements, the Company determined that substantially all of the fair value of each individual agreement was attributable to in-process research and development and no substantive processes were acquired that would constitute a business. The Company concluded that it did not have any alternative future use for the acquired in-process research and development associated with the agreements and recorded the related portion of the upfront payments to “Research and development expenses.” Please refer to Note D, “Fair Value Measurements,” and Note E, “Marketable Securities and Equity Investments,” for further information regarding the Company’s investments in its collaborators. Variable Interest Entities (VIEs) The Company licensed rights to certain drug candidates from these third-party collaborators, which has resulted in the consolidation of the third-parties’ financial statements into the Company’s consolidated financial statements as VIEs for certain periods of time. Most recently, the Company deconsolidated the financial statements of BioAxone from its consolidated financial statements as of December 31, 2018. The Company has not consolidated a VIE into its financial statements since December 31, 2018. BioAxone Biosciences, Inc. In 2014, the Company entered into a license and collaboration agreement (the “BioAxone Agreement”) with BioAxone, which resulted in the consolidation of BioAxone as a VIE. In October 2018, the Company announced it would stop clinical development of VX-210 and terminate the Phase 2b clinical trial of VX-210 based on the recommendation of the clinical trial’s Data Safety Monitoring Board and the Company’s review of interim data. In December 2018, the Company notified BioAxone of its intent to terminate the BioAxone Agreement and executed a release that immediately allowed BioAxone to control development of its neurological programs other than VX-210 without the Company’s consent. As a result of this decision, the Company recorded a $29.0 million impairment charge related to VX-210 that was attributable to noncontrolling interest. As a result, the Company deconsolidated BioAxone as of December 31, 2018 because it determined that it no longer was the primary beneficiary of BioAxone as it no longer had the power to direct the significant activities of BioAxone. The net impact of the deconsolidation was not material to the Company’s consolidated statement of operations. The Company’s net loss attributable to noncontrolling interest for the year ended December 31, 2018 was $9.8 million. Out-license Agreements The Company has entered into licensing agreements pursuant to which it has out-licensed rights to certain drug candidates to third-party collaborators. Pursuant to these out-license agreements, the Company’s collaborators become responsible for all costs related to the continued development of such drug candidates and obtain development and commercialization rights to these drug candidates. Depending on the terms of the agreements, the Company’s collaborators may be required to make upfront payments, milestone payments upon the achievement of certain product research and development objectives and may also be required to pay royalties on future sales, if any, of commercial products resulting from the collaboration. The termination provisions associated with these collaborations are generally the same as those described above related to the Company’s in-license agreements. Merck KGaA, Darmstadt, Germany In January 2017, the Company entered into a strategic collaboration and license agreement (the “Oncology Agreement”) with Merck KGaA, Darmstadt, Germany (the “Licensee”). Pursuant to the Oncology Agreement, the Company granted the Licensee an exclusive worldwide license to research, develop and commercialize four oncology research and development programs including two clinical-stage programs targeting DNA damage repair: its ataxia telangiectasia and Rad3-related protein kinase inhibitor program, or ATR program, including VX-970 and VX-803, and its DNA-dependent protein kinase inhibitor program, or DNA-PK program, including VX-984. In addition, the Company granted the Licensee exclusive, worldwide rights to two pre-clinical programs. The Oncology Agreement provided for an upfront payment from the Licensee to the Company of $230.0 million, which was recorded as “Collaborative and royalty revenues,” under the multiple element arrangement accounting guidance that was applicable in 2017. All of the Company’s activities related to the Oncology Agreement were substantially complete as of December 31, 2017. In December 2018, the Company entered into an agreement with Merck KGaA, Darmstadt, Germany (the “DNA-PK Agreement”) whereby the Company licensed the two lead Vertex DNA-PK compounds from its DNA-PK program for use in the field of gene integration for six specific indications. In exchange for this exclusive worldwide license to research, develop and commercialize the DNA-PK program for the specified indications within the field of gene integration, the Company made an upfront payment of $65.0 million. Merck KGaA, Darmstadt, Germany has the potential to receive additional milestones, primarily related to approval and reimbursement in various markets, as well as royalties on net product sales. The Company evaluated the DNA-PK Agreement and concluded it represents a modification of the Oncology Agreement pursuant to ASC 606. As of December 2018, when the Company entered into the DNA-PK Agreement, the Company had completed its obligations under the Oncology Agreement, but the Oncology Agreement was an open contract pursuant to ASC 606 since the Company could receive future royalty payments from the commercialization of the licensed programs under the Oncology Agreement. In applying ASC 606, the Company determined that the license granted under the DNA-PK Agreement is distinct from the license granted by the Company under the Oncology Agreement since the license to the two lead Vertex DNA-PK compounds is capable of being distinct as the Company is able to benefit from the license via its ability to internally develop and commercialize the two lead Vertex DNA-PK compounds in the six named indications in the field of gene-editing, and the license is not dependent on Merck KGaA, Darmstadt, Germany providing any specialized services to the Company. In addition, the license to the two lead Vertex DNA-PK compounds granted to the Company under the DNA-PK Agreement is distinct from the license granted by the Company under the Oncology Agreement as the rights conveyed in the licenses differ and both parties have the ability to commercially benefit from the licenses on their own. Furthermore, the consideration attributable to the license of the two lead Vertex DNA-PK compounds represents fair value. Therefore, the Company determined it should account for the DNA-PK Agreement as a separate agreement. The Company determined that substantially all of the fair value of the DNA-PK Agreement was attributable to a single in-process research and development asset that did not constitute a business. The Company concluded that it did not have any alternative future use for the acquired in-process research and development and recorded the $65.0 million payment to “Research and development expenses” in 2018 accordingly. Janssen Pharmaceuticals, Inc. In 2014, the Company entered into an agreement with Janssen Pharmaceuticals, Inc. (“Janssen”). In the third quarter of 2020, Janssen exercised its right to terminate its exclusive worldwide license to develop and commercialize certain drug candidates for the treatment of influenza, based on Phase 3 clinical trial results for pimodivir. Cystic Fibrosis Foundation The Company has a research, development and commercialization agreement that was originally entered into in 2004 with the Cystic Fibrosis Foundation, as successor in interest to the Cystic Fibrosis Foundation Therapeutics, Inc. This agreement was most recently amended in 2016. Pursuant to the agreement, as amended, the Company agreed to pay royalties ranging from low-single digits to mid-single digits on potential sales of certain compounds first synthesized and/or tested between March 1, 2014 and August 31, 2016, including elexacaftor, and tiered royalties ranging from single digits to sub-teens on covered compounds first synthesized and/or tested during a research term on or before February 28, 2014, including KALYDECO (ivacaftor), ORKAMBI (lumacaftor in combination with ivacaftor) and SYMDEKO/SYMKEVI (tezacaftor in combination with ivacaftor). For combination products, such as ORKAMBI, SYMDEKO/SYMKEVI and TRIKAFTA/KAFTRIO (elexacaftor/tezacaftor/ivacaftor and ivacaftor), sales are allocated equally to each of the active pharmaceutical ingredients in the combination product.

The Company has entered into a number of license agreements in order to advance and obtain access to technologies and services related to its research and early-development activities. The Company is generally required to make an upfront payment upon execution of the license agreement; development, regulatory and commercialization milestones payments upon the achievement of certain product research, development and commercialization objectives; and royalty payments on future sales, if any, of commercial products resulting from the collaboration.

Pursuant to the terms of its in-license agreements, the Company’s collaborators typically lead the discovery efforts and the Company leads all preclinical, development and commercialization activities associated with the advancement of any drug candidates and funds all expenses.

The Company typically can terminate its in-license agreements by providing advance notice to its collaborators; the required length of notice is dependent on whether any product developed under the license agreement has received marketing approval. The Company’s license agreements may be terminated by either party for a material breach by the other, subject to notice and cure provisions. Unless earlier terminated, these license agreements generally remain in effect until the date on which the royalty term and all payment obligations with respect to all products in all countries have expired.

In 2015, the Company entered into a strategic collaboration, option and license agreement (the “CRISPR Agreement”) with CRISPR Therapeutics AG and its affiliates (“CRISPR”) to collaborate on the discovery and development of potential new treatments aimed at the underlying genetic causes of human diseases using CRISPR-Cas9 gene-editing technology. The Company had the exclusive right to license certain targets. In the fourth quarter of 2019, the Company paid an aggregate of $30.0 million to exclusively license three CRISPR-Cas9-based targets, including CF, pursuant to the CRISPR Agreement. The Company recorded the $30.0 million total option payment to “Research and development expenses” in the fourth quarter of 2019. For each of the three targets that the Company elected to license, CRISPR has the potential to receive up to an additional $410.0 million in development, regulatory and commercial milestones as well as royalties on net product sales.

In 2017, the Company entered into a co-development and co-commercialization agreement with CRISPR pursuant to the terms of the CRISPR Agreement, under which the Company and CRISPR are co-developing and will co-commercialize CTX001 (the “CTX001 Co-Co Agreement”) for the treatment of hemoglobinopathies, including treatments for sickle cell disease and beta thalassemia. As part of the collaboration, the Company and CRISPR share equally all development costs and potential worldwide revenues related to potential hemoglobinopathy treatments. The Company concluded that the CTX001 Co-Co Agreement is a cost-sharing arrangement, which results in the net impact of the arrangement being recorded in “Research and development expenses” in its consolidated statements of operations. During the years ended December 31, 2020, 2019 and 2018, the net expense related to the CTX001 Co-Co Agreement was $50.6 million, $30.1 million and $19.7 million, respectively.

In July 2019, the Company entered into a separate strategic collaboration and license agreement (the “CRISPR DMD/DM1 Agreement”) with CRISPR. Pursuant to this agreement, the Company received an exclusive worldwide license to CRISPR’s existing and future intellectual property for Duchenne muscular dystrophy (“DMD”) and myotonic dystrophy type 1 (“DM1”) and the Company made an upfront payment of $175.0 million to CRISPR. The Company concluded that it did not have any alternative future use for the acquired in-process research and development and recorded the upfront payment to “Research and development expenses” in the third quarter of 2019. In 2020, the Company recorded $25.0 million to “Research and development expenses” related to a pre-clinical milestone earned by CRISPR under the CRISPR DMD/DM1 Agreement. CRISPR has the potential to receive up to an additional $800.0 million in research, development, regulatory and commercial milestones for the DMD and DM1 programs as well as royalties on net product sales. CRISPR has the option to co-develop and co-commercialize all DM1 products globally and forego the milestones and royalties associated with the

In May 2019, the Company entered into a strategic research and development collaboration agreement with Kymera Therapeutics Inc. (“Kymera”) to advance small molecule protein degraders against multiple targets. Kymera’s proprietary platform technology is being applied in the collaboration activities in exchange for an upfront payment of $50.0 million. The Company has the exclusive right to license up to six protein targets, for each of which Kymera may receive up to $170.0 million in payments, including development, regulatory and commercial milestones as well as royalties on net product sales. In addition to the upfront payment, the Company purchased $20.0 million of Kymera’s preferred stock. The Company determined that the fair value of its investment in Kymera’s preferred stock, which did not have a readily determinable fair value, approximated $20.0 million. The preferred stock converted to common stock when Kymera became a publicly traded company in 2020.

The Company determined that substantially all of the fair value of the Kymera collaboration agreement was attributable to in-process research and development and no substantive processes were acquired that would constitute a business. The Company concluded that it did not have any alternative future use for the acquired in-process research and development and recorded the $50.0 million upfront payment to “Research and development expenses” in 2019.

In 2016, the Company entered into a strategic collaboration and licensing agreement with Moderna, Inc. (“Moderna”), pursuant to which the parties are seeking to identify and develop messenger ribonucleic acid (“mRNA”) therapeutics for the treatment of CF.

In September 2020, the Company entered into a new strategic collaboration and licensing agreement with Moderna (the “2020 Moderna Agreement”) aimed at the discovery and development of lipid nanoparticles and mRNAs that can deliver gene-editing therapies to lung cells for the treatment of CF. Pursuant to the 2020 Moderna Agreement, Moderna received an upfront payment of $75.0 million and is eligible to receive up to $380.0 million in development, regulatory and commercial milestones as well as royalties on net product sales. The Company determined that substantially all of the fair value of the 2020 Moderna Agreement was attributable to in-process research and development and no substantive processes were acquired that would constitute a business. The Company concluded that it did not have any alternative future use for the acquired in-process research and development and recorded the upfront payment to “Research and development expenses” in the third quarter of 2020.

In addition to the collaborative arrangements described above, the Company has entered into additional in-license agreements that it does not consider to be individually significant to its consolidated financial statements. In addition to the payments described above, the Company recorded upfront, option and milestone payments totaling $84.6 million in 2020, $63.3 million in 2019 and $46.9 million in 2018 to “Research and development expenses” which included a $40.0 million upfront payment to Skyhawk Therapeutics, Inc. (“Skyhawk”) in 2020.

For Skyhawk and several other in-license agreements that are not individually significant to the Company’s consolidated financial statements, the Company determined that substantially all of the fair value of each individual agreement was attributable to in-process research and development and no substantive processes were acquired that would constitute a business. The Company concluded that it did not have any alternative future use for the acquired in-process research and development associated with the agreements and recorded the related portion of the upfront payments to “Research and development expenses.” Please refer to Note D, “Fair Value Measurements,” and Note E, “Marketable Securities and Equity Investments,” for further information regarding the Company’s investments in its collaborators.

The Company licensed rights to certain drug candidates from these third-party collaborators, which has resulted in the consolidation of the third-parties’ financial statements into the Company’s consolidated financial statements as VIEs for

certain periods of time. Most recently, the Company deconsolidated the financial statements of BioAxone from its consolidated financial statements as of December 31, 2018. The Company has not consolidated a VIE into its financial statements since December 31, 2018.

In October 2018, the Company announced it would stop clinical development of VX-210 and terminate the Phase 2b clinical trial of VX-210 based on the recommendation of the clinical trial’s Data Safety Monitoring Board and the Company’s review of interim data. In December 2018, the Company notified BioAxone of its intent to terminate the BioAxone Agreement and executed a release that immediately allowed BioAxone to control development of its neurological programs other than VX-210 without the Company’s consent. As a result of this decision, the Company recorded a $29.0 million impairment charge related to VX-210 that was attributable to noncontrolling interest.

As a result, the Company deconsolidated BioAxone as of December 31, 2018 because it determined that it no longer was the primary beneficiary of BioAxone as it no longer had the power to direct the significant activities of BioAxone. The net impact of the deconsolidation was not material to the Company’s consolidated statement of operations. The Company’s net loss attributable to noncontrolling interest for the year ended December 31, 2018 was $9.8 million.

The Company has entered into licensing agreements pursuant to which it has out-licensed rights to certain drug candidates to third-party collaborators. Pursuant to these out-license agreements, the Company’s collaborators become responsible for all costs related to the continued development of such drug candidates and obtain development and commercialization rights to these drug candidates. Depending on the terms of the agreements, the Company’s collaborators may be required to make upfront payments, milestone payments upon the achievement of certain product research and development objectives and may also be required to pay royalties on future sales, if any, of commercial products resulting from the collaboration. The termination provisions associated with these collaborations are generally the same as those described above related to the Company’s in-license agreements.

In January 2017, the Company entered into a strategic collaboration and license agreement (the “Oncology Agreement”) with Merck KGaA, Darmstadt, Germany (the “Licensee”). Pursuant to the Oncology Agreement, the Company granted the Licensee an exclusive worldwide license to research, develop and commercialize four oncology research and development programs including two clinical-stage programs targeting DNA damage repair: its ataxia telangiectasia and Rad3-related protein kinase inhibitor program, or ATR program, including VX-970 and VX-803, and its DNA-dependent protein kinase inhibitor program, or DNA-PK program, including VX-984. In addition, the Company granted the Licensee exclusive, worldwide rights to two pre-clinical programs.

The Oncology Agreement provided for an upfront payment from the Licensee to the Company of $230.0 million, which was recorded as “Collaborative and royalty revenues,” under the multiple element arrangement accounting guidance that was applicable in 2017. All of the Company’s activities related to the Oncology Agreement were substantially complete as of December 31, 2017.

In December 2018, the Company entered into an agreement with Merck KGaA, Darmstadt, Germany (the “DNA-PK Agreement”) whereby the Company licensed the two lead Vertex DNA-PK compounds from its DNA-PK program for use in the field of gene integration for six specific indications. In exchange for this exclusive worldwide license to research, develop and commercialize the DNA-PK program for the specified indications within the field of gene integration, the Company made an upfront payment of $65.0 million. Merck KGaA, Darmstadt, Germany has the potential to receive additional milestones, primarily related to approval and reimbursement in various markets, as well as royalties on net product sales.

completed its obligations under the Oncology Agreement, but the Oncology Agreement was an open contract pursuant to ASC 606 since the Company could receive future royalty payments from the commercialization of the licensed programs under the Oncology Agreement.

In applying ASC 606, the Company determined that the license granted under the DNA-PK Agreement is distinct from the license granted by the Company under the Oncology Agreement since the license to the two lead Vertex DNA-PK compounds is capable of being distinct as the Company is able to benefit from the license via its ability to internally develop and commercialize the two lead Vertex DNA-PK compounds in the six named indications in the field of gene-editing, and the license is not dependent on Merck KGaA, Darmstadt, Germany providing any specialized services to the Company. In addition, the license to the two lead Vertex DNA-PK compounds granted to the Company under the DNA-PK Agreement is distinct from the license granted by the Company under the Oncology Agreement as the rights conveyed in the licenses differ and both parties have the ability to commercially benefit from the licenses on their own. Furthermore, the consideration attributable to the license of the two lead Vertex DNA-PK compounds represents fair value. Therefore, the Company determined it should account for the DNA-PK Agreement as a separate agreement.

The Company determined that substantially all of the fair value of the DNA-PK Agreement was attributable to a single in-process research and development asset that did not constitute a business. The Company concluded that it did not have any alternative future use for the acquired in-process research and development and recorded the $65.0 million payment to “Research and development expenses” in 2018 accordingly.

In 2014, the Company entered into an agreement with Janssen Pharmaceuticals, Inc. (“Janssen”). In the third quarter of 2020, Janssen exercised its right to terminate its exclusive worldwide license to develop and commercialize certain drug candidates for the treatment of influenza, based on Phase 3 clinical trial results for pimodivir.