Commitments and Contingencies	3 Months Ended
Mar. 31, 2025
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	9. Commitments and Contingencies MSK In-License Agreements In June 2015, we entered into an exclusive license agreement with MSK for three clinical stage T-cell therapies. We are required to make payments to MSK based on achievement of specified regulatory and sales-related milestones, as well as mid-single-digit percentage tiered royalty payments based on future sales of products resulting from the development of the licensed product candidates, if any. In addition, under certain circumstances, we are required to make certain minimum annual royalty payments to MSK, which are creditable against earned royalties owed for the same annual period. We are also required to pay a low double-digit percentage of any consideration we receive for sublicensing the licensed rights, subject to certain conditions. The license agreement expires on a product-by-product and country-by-country basis on the latest of: (i) expiration of the last licensed patent rights related to each licensed product, (ii) expiration of any market exclusivity period granted by law with respect to each licensed product, and (iii) a specified number of years after the first commercial sale of the licensed product in each country. Upon expiration of the license agreement, we will retain non-exclusive rights to the licensed products. In May and December 2018, we licensed additional technology from MSK. We are obligated to make additional milestone payments based on achievement of specified development, regulatory and sales-related milestones as well as mid-single-digit percentage tiered royalty payments based on future sales of products resulting from the development of the licensed product candidates, if any. In March 2021, we amended and restated our license agreement with MSK to terminate our license to certain rights and license additional know-how rights not otherwise covered by our existing agreements. In March 2024, we terminated our license agreements with MSK to the ATA2271 and ATA3271 programs targeting mesothelin. During the third quarter of 2024, MSK sent us a notice alleging that under the terms of our license agreements with MSK, MSK is entitled to $6.0 million of sub-licensing fees as a result of the $60.0 million we received from Pierre Fabre related to the Additional Territory upfront and milestone payments in 2024 pursuant to the A&R Commercialization Agreement. We paid the $6.0 million to MSK under protest in the third quarter of 2024 in order to proceed with the dispute process per the terms of the license agreements. We recorded this cost in research and development expenses on the consolidated statements of operations and comprehensive income (loss) during the year ended December 31, 2024. In March 2025, we resolved and settled our dispute with MSK regarding sub-licensing fees related to the Additional Territory and milestone payments pursuant to the A&R Commercialization Agreement. Under the terms of the settlement, MSK returned $3.0 million of the $6.0 million paid under protest and we agreed to make future additional sub-licensing fee payments based on amounts we receive from Pierre Fabre pursuant to the A&R Commercialization Agreement based on achievement of specified development, regulatory and sales-related milestones. QIMR Berghofer In-License Agreements In October 2015, we entered into an exclusive license agreement and a research and development collaboration agreement with QIMR Berghofer. Under the terms of the license agreement, we obtained an exclusive, worldwide license to develop and commercialize allogeneic T-cell therapy programs utilizing technology and know-how developed by QIMR Berghofer. In September 2016, the exclusive license agreement and research and development collaboration agreement were amended and restated. Under the amended and restated agreements, we obtained an exclusive, worldwide license to develop and commercialize additional T-cell programs, as well as the option to license additional technology that we exercised in June 2018. We further amended and restated our license agreement and research and development collaboration agreements with QIMR Berghofer in August 2019, August 2020 and December 2021, in each case, to terminate our license to certain rights. Our current license agreement also provides for various milestone and royalty payments to QIMR Berghofer based on future product sales, if any. Under the terms of our current research and development collaboration agreement, we are also required to reimburse the cost of agreed-upon development activities related to programs developed under the collaboration. These payments are expensed on a straight-line basis over the related development periods. The agreement also provides for various milestone payments to QIMR Berghofer based on achievement of certain developmental and regulatory milestones. We are in discussions with QIMR Berghofer to return rights to ATA188 and the EBV vaccine to QIMR Berghofer. Other In-License and Collaboration Agreements From time to time, we have entered into other license and collaboration agreements with other parties. For example, we licensed rights related to our MSK-partnered next-generation CAR T programs from the National Institutes of Health in December 2018. Milestones and royalties under each of the above agreements are contingent upon future events and will be recorded as expense when the underlying milestones are achieved or royalties are earned. Sales related milestone and royalty costs related to Ebvallo are recorded in cost of commercialization revenue, whereas regulatory milestone costs are recorded in research and development expense. As of March 31, 2025 and December 31, 2024, there were no material outstanding obligations for milestones and royalties under our in-license and collaboration agreements. CRL Manufacturing Agreement In December 2019, we entered into a Commercial Manufacturing Services Agreement (the CRL MSA) with Cognate BioServices, Inc., which was acquired by Charles River Laboratories Inc. (CRL) in March 2021. The CRL MSA expired on August 31, 2024 and we have transitioned manufacturing responsibility for tab-cel to Pierre Fabre. Fujifilm Master Services and Supply Agreement In January 2022, we entered into the Fujifilm MSA, which became effective upon the closing of the sale of the ATOM Facility on April 4, 2022 and could extend for up to ten years. Pursuant to the Fujifilm MSA, FDB will supply us with specified quantities of our cell therapy products and product candidates, manufactured in accordance with current Good Manufacturing Practices (cGMP) standards. In March 2025, in connection with the transition of manufacturing responsibility for tab-cel to Pierre Fabre, we assigned the Fujifilm MSA to Pierre Fabre. Other Research, Development and Manufacturing Agreements We may enter into other contracts in the normal course of business with clinical research organizations for clinical trials, with CMOs for product, product candidates and clinical supplies, and with other vendors for preclinical studies, supplies and other services for our operating purposes. These contracts generally provide for termination on notice. As of March 31, 2025 and December 31, 2024, there were no material amounts accrued related to contract termination charges. Minimum Commitments We have non-cancellable minimum commitments for products and services, subject to agreements with a term of greater than one year with clinical research organizations and CMOs. For the three months ended March 31, 2025, we incurred $0.5 million against the minimum commitments. In March 2025, we assigned these agreements to Pierre Fabre in conjunction with the Pierre Fabre Amendment. Because we assigned these agreements to Pierre Fabre as of March 31, 2025, we cannot reasonably estimate an amount to be accrued related to minimum purchase commitments. For the comparative periods presented, we incurred $3.5 million against the minimum commitments for the three months ended March 31, 2024. As of December 31, 2024, we accrued $5.3 million, in research and development expenses related to minimum purchase commitments. Indemnification Agreements In the normal course of business, we enter into contracts and agreements that contain a variety of representations and warranties and provide for indemnification for certain liabilities. The exposure under these agreements is unknown because it involves claims that may be made against us in the future but have not yet been made. To date, we have not paid any claims or been required to defend any action related to our indemnification obligations. However, we may record charges in the future as a result of these indemnification obligations. We also have indemnification obligations to our directors and executive officers for specified events or occurrences, subject to some limits, while they are serving at our request in such capacities. There have been no claims to date, and we consider the fair value of these indemnification agreements to be minimal. Accordingly, we did not record liabilities for these agreements as of March 31, 2025 and December 31, 2024. Contingencies From time to time, we may be involved in legal proceedings, as well as demands, claims and threatened litigation, which arise in the normal course of our business or otherwise. The ultimate outcome of any litigation is uncertain and unfavorable outcomes could have a negative impact on our results of operations and financial condition. Regardless of outcome, litigation can have an adverse impact on us because of the defense costs, diversion of management resources and other factors. We are not currently involved in any material legal proceedings.

Commitments and Contingencies

3 Months Ended

Mar. 31, 2025

Commitments and Contingencies Disclosure [Abstract]

MSK In-License Agreements

In June 2015, we entered into an exclusive license agreement with MSK for three clinical stage T-cell therapies. We are required to make payments to MSK based on achievement of specified regulatory and sales-related milestones, as well as mid-single-digit percentage tiered royalty payments based on future sales of products resulting from the development of the licensed product candidates, if any. In addition, under certain circumstances, we are required to make certain minimum annual royalty payments to MSK, which are creditable against earned royalties owed for the same annual period. We are also required to pay a low double-digit percentage of any consideration we receive for sublicensing the licensed rights, subject to certain conditions. The license agreement expires on a product-by-product and country-by-country basis on the latest of: (i) expiration of the last licensed patent rights related to each licensed product, (ii) expiration of any market exclusivity period granted by law with respect to each licensed product, and (iii) a specified number of years after the first commercial sale of the licensed product in each country. Upon expiration of the license agreement, we will retain non-exclusive rights to the licensed products.

In May and December 2018, we licensed additional technology from MSK. We are obligated to make additional milestone payments based on achievement of specified development, regulatory and sales-related milestones as well as mid-single-digit percentage tiered royalty payments based on future sales of products resulting from the development of the licensed product candidates, if any.

In March 2021, we amended and restated our license agreement with MSK to terminate our license to certain rights and license additional know-how rights not otherwise covered by our existing agreements.

In March 2024, we terminated our license agreements with MSK to the ATA2271 and ATA3271 programs targeting mesothelin.

During the third quarter of 2024, MSK sent us a notice alleging that under the terms of our license agreements with MSK, MSK is entitled to $6.0 million of sub-licensing fees as a result of the $60.0 million we received from Pierre Fabre related to the Additional Territory upfront and milestone payments in 2024 pursuant to the A&R Commercialization Agreement. We paid the $6.0 million to MSK under protest in the third quarter of 2024 in order to proceed with the dispute process per the terms of the license agreements. We recorded this cost in research and development expenses on the consolidated statements of operations and comprehensive income (loss) during the year ended December 31, 2024.

In March 2025, we resolved and settled our dispute with MSK regarding sub-licensing fees related to the Additional Territory and milestone payments pursuant to the A&R Commercialization Agreement. Under the terms of the settlement, MSK returned $3.0 million of the $6.0 million paid under protest and we agreed to make future additional sub-licensing fee payments based on amounts we receive from Pierre Fabre pursuant to the A&R Commercialization Agreement based on achievement of specified development, regulatory and sales-related milestones.

QIMR Berghofer In-License Agreements

In October 2015, we entered into an exclusive license agreement and a research and development collaboration agreement with QIMR Berghofer. Under the terms of the license agreement, we obtained an exclusive, worldwide license to develop and commercialize allogeneic T-cell therapy programs utilizing technology and know-how developed by QIMR Berghofer. In September 2016, the exclusive license agreement and research and development collaboration agreement were amended and restated. Under the amended and restated agreements, we obtained an exclusive, worldwide license to develop and commercialize additional T-cell programs, as well as the option to license additional technology that we exercised in June 2018. We further amended and restated our license agreement and research and development collaboration agreements with QIMR Berghofer in August 2019, August 2020 and December 2021, in each case, to terminate our license to certain rights. Our current license agreement also provides for various milestone and royalty payments to QIMR Berghofer based on future product sales, if any. Under the terms of our current research and development collaboration agreement, we are also required to reimburse the cost of agreed-upon development activities related to programs developed under the collaboration. These payments are expensed on a straight-line basis over the related development periods. The agreement also provides for various milestone payments to QIMR Berghofer based on achievement of certain developmental and regulatory milestones. We are in discussions with QIMR Berghofer to return rights to ATA188 and the EBV vaccine to QIMR Berghofer.

Other In-License and Collaboration Agreements

From time to time, we have entered into other license and collaboration agreements with other parties. For example, we licensed rights related to our MSK-partnered next-generation CAR T programs from the National Institutes of Health in December 2018.

Milestones and royalties under each of the above agreements are contingent upon future events and will be recorded as expense when the underlying milestones are achieved or royalties are earned. Sales related milestone and royalty costs related to Ebvallo are recorded in cost of commercialization revenue, whereas regulatory milestone costs are recorded in research and development expense. As of March 31, 2025 and December 31, 2024, there were no material outstanding obligations for milestones and royalties under our in-license and collaboration agreements.

CRL Manufacturing Agreement

In December 2019, we entered into a Commercial Manufacturing Services Agreement (the CRL MSA) with Cognate BioServices, Inc., which was acquired by Charles River Laboratories Inc. (CRL) in March 2021. The CRL MSA expired on August 31, 2024 and we have transitioned manufacturing responsibility for tab-cel to Pierre Fabre.

Fujifilm Master Services and Supply Agreement

In January 2022, we entered into the Fujifilm MSA, which became effective upon the closing of the sale of the ATOM Facility on April 4, 2022 and could extend for up to ten years. Pursuant to the Fujifilm MSA, FDB will supply us with specified quantities of our cell therapy products and product candidates, manufactured in accordance with current Good Manufacturing Practices (cGMP) standards. In March 2025, in connection with the transition of manufacturing responsibility for tab-cel to Pierre Fabre, we assigned the Fujifilm MSA to Pierre Fabre.

Other Research, Development and Manufacturing Agreements

We may enter into other contracts in the normal course of business with clinical research organizations for clinical trials, with CMOs for product, product candidates and clinical supplies, and with other vendors for preclinical studies, supplies and

other services for our operating purposes. These contracts generally provide for termination on notice. As of March 31, 2025 and December 31, 2024, there were no material amounts accrued related to contract termination charges.

Minimum Commitments

We have non-cancellable minimum commitments for products and services, subject to agreements with a term of greater than one year with clinical research organizations and CMOs. For the three months ended March 31, 2025, we incurred $0.5 million against the minimum commitments. In March 2025, we assigned these agreements to Pierre Fabre in conjunction with the Pierre Fabre Amendment. Because we assigned these agreements to Pierre Fabre as of March 31, 2025, we cannot reasonably estimate an amount to be accrued related to minimum purchase commitments.

For the comparative periods presented, we incurred $3.5 million against the minimum commitments for the three months ended March 31, 2024. As of December 31, 2024, we accrued $5.3 million, in research and development expenses related to minimum purchase commitments.

Indemnification Agreements

In the normal course of business, we enter into contracts and agreements that contain a variety of representations and warranties and provide for indemnification for certain liabilities. The exposure under these agreements is unknown because it involves claims that may be made against us in the future but have not yet been made. To date, we have not paid any claims or been required to defend any action related to our indemnification obligations. However, we may record charges in the future as a result of these indemnification obligations. We also have indemnification obligations to our directors and executive officers for specified events or occurrences, subject to some limits, while they are serving at our request in such capacities. There have been no claims to date, and we consider the fair value of these indemnification agreements to be minimal. Accordingly, we did not record liabilities for these agreements as of March 31, 2025 and December 31, 2024.

Contingencies

From time to time, we may be involved in legal proceedings, as well as demands, claims and threatened litigation, which arise in the normal course of our business or otherwise. The ultimate outcome of any litigation is uncertain and unfavorable outcomes could have a negative impact on our results of operations and financial condition. Regardless of outcome, litigation can have an adverse impact on us because of the defense costs, diversion of management resources and other factors. We are not currently involved in any material legal proceedings.