Collaboration and License Agreements	12 Months Ended
Dec. 31, 2023
Collaboration And License Agreements [Abstract]
Collaboration and License Agreements	9. Collaboration and License Agreements Amgen On May 8, 2023, the Company entered into a Collaboration Agreement with Amgen Inc. (the Amgen Agreement) to identify antigens recognized by T cells in patients with Crohn’s disease in accordance with a research plan. Under the terms of the Amgen Agreement, Amgen will retain all global development and commercialization rights. The proceeds from the Amgen Agreements included an upfront payment of $30.0 million, which was collected in July 2023. In addition, the Company is eligible to earn success-based milestone payments of over $500 million, based upon the achievement of certain clinical development and commercial milestones, as well as tiered single-digit royalty payments on net sales of products developed from the collaboration, subject to reductions set forth in the Amgen Agreement. The Company concluded that Amgen meets the definition of a customer, as the Company is delivering research and development activities and a license of intellectual property. The Company identified performance obligations for research and development activities, the license, data reporting and participation in joint steering and research committees, which were determined to be a single combined performance obligation due to the services and licenses being highly interrelated. For a certain time period during the term of the Amgen Agreement, Amgen has an option to add targets to the collaboration for payments specified in the agreement. Pursuant to the Amgen Agreement, the option for Amgen to select additional targets and to license, develop, and commercialize targets is not a performance obligation at the outset as these are customer options that do not represent material rights. The Company looked to the promises in the arrangement to determine the method of recognition that best depicted the transfer of the services and the satisfaction of the combined performance obligations. The Company concluded that the performance of the research services over the expected research term was the predominant promise within the performance obligation. The Company will recognize the revenue associated with the performance obligation using an input method. The method of measuring progress towards delivery of the services incorporates actual internal and external costs incurred, relative to total internal and external costs expected to be incurred to satisfy the performance obligation. Changes in estimates of total internal and external costs expected to be incurred are recognized in the period of change as a cumulative catch-up adjustment. As costs are incurred, the Company will recognized revenue over time. At this time, it is estimated that the research term will be approximately 3 years. The Company determined the $30.0 million upfront payment to be the entirety of the consideration to be included in the transaction price. The option to add additional targets was not included in the transaction price as this option was assessed to be improbable at this time. The potential milestone and royalty payments that the Company is eligible to receive were also excluded from the transaction price, as all milestone and royalty amounts were fully constrained based on the assessed probability of achievement. The Company will continue to assess the probability of the option to add additional targets and the probability of milestone achievement throughout the research term and will adjust the consideration in the contract accordingly. For the year ended December 31, 2023, the Company recognized $14.2 million of revenue associated with the Amgen Agreement. As of December 31, 2023, the Company recorded $15.8 million of deferred revenue, of which $5.6 million is classified as long-term. Novartis In March 2020, the Company entered into a Collaboration and License Agreement (the Novartis Agreement) with Novartis Institutes For BioMedical Research, Inc. (Novartis) to collaborate on their research efforts to discover and develop novel TCR-T therapies. At the inception date of the Novartis Agreement, Novartis or its affiliates held an ownership interest of more than 10% in the Company, and at December 31, 2023 and 2022, Novartis held less than 10% of the common shares outstanding. Under the Novartis Agreement, the Company was to identify and characterize TCRs in accordance with a research plan, and transfer data arising from the research plan. The Novartis Agreement provided for payments of an upfront fee of $20.0 million, research funding totaling $10.0 million, and potential milestone payments contingent on clinical, regulatory and sales success. The Company concluded that the performance of the research services was the predominant performance obligation and was recognizing the revenue associated with the performance obligation using the input method, according to the actual costs incurred as a percentage of total expected costs to complete the research services. The Company determined that the $20.0 million upfront payment, together with the $10.0 million of estimated research costs to be reimbursed by Novartis to be the entirety of the consideration to be included in the transaction price as of the outset of the arrangement. The potential milestone payments that the Company is eligible to receive were excluded from the transaction price, as all milestone amounts were fully constrained based on the assessed probability of achievement. During the years ended December 31, 2023 and 2022, the Company recognized $5.8 million and $13.5 million, respectively, of revenue associated with the Novartis Agreement, of which $1.9 million and $4.5 million, respectively, related to cost reimbursements under the Novartis Agreement that offset costs incurred within research and development expenses in the statements of operations. The research term ended in March 2023.

Collaboration and License Agreements

12 Months Ended

Dec. 31, 2023

Collaboration And License Agreements [Abstract]

9. Collaboration and License Agreements

Amgen

On May 8, 2023, the Company entered into a Collaboration Agreement with Amgen Inc. (the Amgen Agreement) to identify antigens recognized by T cells in patients with Crohn’s disease in accordance with a research plan. Under the terms of the Amgen Agreement, Amgen will retain all global development and commercialization rights. The proceeds from the Amgen Agreements included an upfront payment of $30.0 million, which was collected in July 2023. In addition, the Company is eligible to earn

success-based milestone payments of over $500 million, based upon the achievement of certain clinical development and commercial milestones, as well as tiered single-digit royalty payments on net sales of products developed from the collaboration, subject to reductions set forth in the Amgen Agreement.

The Company concluded that Amgen meets the definition of a customer, as the Company is delivering research and development activities and a license of intellectual property. The Company identified performance obligations for research and development activities, the license, data reporting and participation in joint steering and research committees, which were determined to be a single combined performance obligation due to the services and licenses being highly interrelated.

For a certain time period during the term of the Amgen Agreement, Amgen has an option to add targets to the collaboration for payments specified in the agreement. Pursuant to the Amgen Agreement, the option for Amgen to select additional targets and to license, develop, and commercialize targets is not a performance obligation at the outset as these are customer options that do not represent material rights.

The Company looked to the promises in the arrangement to determine the method of recognition that best depicted the transfer of the services and the satisfaction of the combined performance obligations. The Company concluded that the performance of the research services over the expected research term was the predominant promise within the performance obligation. The Company will recognize the revenue associated with the performance obligation using an input method. The method of measuring progress towards delivery of the services incorporates actual internal and external costs incurred, relative to total internal and external costs expected to be incurred to satisfy the performance obligation. Changes in estimates of total internal and external costs expected to be incurred are recognized in the period of change as a cumulative catch-up adjustment. As costs are incurred, the Company will recognized revenue over time. At this time, it is estimated that the research term will be approximately 3 years.

The Company determined the $30.0 million upfront payment to be the entirety of the consideration to be included in the transaction price. The option to add additional targets was not included in the transaction price as this option was assessed to be improbable at this time. The potential milestone and royalty payments that the Company is eligible to receive were also excluded from the transaction price, as all milestone and royalty amounts were fully constrained based on the assessed probability of achievement. The Company will continue to assess the probability of the option to add additional targets and the probability of milestone achievement throughout the research term and will adjust the consideration in the contract accordingly.

For the year ended December 31, 2023, the Company recognized $14.2 million of revenue associated with the Amgen Agreement. As of December 31, 2023, the Company recorded $15.8 million of deferred revenue, of which $5.6 million is classified as long-term.

Novartis

In March 2020, the Company entered into a Collaboration and License Agreement (the Novartis Agreement) with Novartis Institutes For BioMedical Research, Inc. (Novartis) to collaborate on their research efforts to discover and develop novel TCR-T therapies. At the inception date of the Novartis Agreement, Novartis or its affiliates held an ownership interest of more than 10% in the Company, and at December 31, 2023 and 2022, Novartis held less than 10% of the common shares outstanding. Under the Novartis Agreement, the Company was to identify and characterize TCRs in accordance with a research plan, and transfer data arising from the research plan. The Novartis Agreement provided for payments of an upfront fee of $20.0 million, research funding totaling $10.0 million, and potential milestone payments contingent on clinical, regulatory and sales success.

The Company concluded that the performance of the research services was the predominant performance obligation and was recognizing the revenue associated with the performance obligation using the input method, according to the actual costs incurred as a percentage of total expected costs to complete the research services.

The Company determined that the $20.0 million upfront payment, together with the $10.0 million of estimated research costs to be reimbursed by Novartis to be the entirety of the consideration to be included in the transaction price as of the outset of the arrangement. The potential milestone payments that the Company is eligible to receive were excluded from the transaction price, as all milestone amounts were fully constrained based on the assessed probability of achievement.

During the years ended December 31, 2023 and 2022, the Company recognized $5.8 million and $13.5 million, respectively, of revenue associated with the Novartis Agreement, of which $1.9 million and $4.5 million, respectively, related to cost reimbursements under the Novartis Agreement that offset costs incurred within research and development expenses in the statements of operations. The research term ended in March 2023.