Collaboration Agreements and Research and Development Funding Arrangement	6 Months Ended
Jun. 30, 2026
Research and Development [Abstract]
Collaboration Agreements and Research and Development Funding Arrangement	5. Collaboration Agreements and Research and Development Funding Arrangement Merck – Individualized Neoantigen Therapy (Intismeran Autogene) In June 2016, we entered into a Collaboration and License Agreement, which was subsequently amended in 2018, with Merck & Co., Inc. (Merck) for the development and commercialization of individualized neoantigen therapy (INT), which has been assigned the generic name intismeran autogene. In September 2022, Merck exercised its option for intismeran, including mRNA-4157, pursuant to the terms of the agreement and in October 2022 paid us an option exercise fee of $250 million. Following this exercise, the Merck Participation Term commenced. Pursuant to the agreement, we and Merck have agreed to collaborate on development and potential commercialization of intismeran, with costs and any profits or losses generally shared equally on a worldwide basis, subject to certain exceptions as outlined in the agreement. During the development phase, we are primarily responsible for process development and the manufacture of intismeran materials, while Merck generally leads clinical trials. We concluded that the collaboration arrangement under the Merck Participation Term is within the scope of ASC 808. For the three and six months ended June 30, 2026, we recognized expenses, net of Merck's reimbursements, of $97 million and $198 million, respectively, related to the INT collaboration under the Merck Participation Term. For the three and six months ended June 30, 2025, these expenses were $99 million and $203 million, respectively. Additionally, for the three and six months ended June 30, 2026, the net cost recovery for capital expenditures was $1 million and $2 million, respectively. For the three and six months ended June 30, 2025, this amount was $6 million and $18 million, respectively. These amounts were applied to reduce the capitalized cost of the assets. Recordati –Propionic Acidemia Therapeutic In January 2026, we entered into a collaboration agreement with Recordati S.p.A. (Recordati) to advance the development and commercialization of our investigational propionic acidemia therapeutic, mRNA-3927. Under the terms of the agreement, we granted Recordati an exclusive, royalty-bearing license to develop and commercialize the licensed product (mRNA-3927) worldwide, we will perform and continue to lead clinical development activities through approval, and Recordati will lead global commercialization upon approval. The transaction closed on March 16, 2026, and we received a $50 million upfront payment in the second quarter of 2026. The upfront payment is being recognized as collaboration revenue over time. In addition, we are eligible to receive up to $110 million in development and regulatory milestones, as well as additional commercial and sales milestones and tiered royalties on net sales. We have other collaborative and licensing arrangements that we do not consider to be individually significant to our business at this time. Pursuant to these agreements, we may be required to make upfront payments and payments upon achievement of various development, regulatory and commercial milestones, which in the aggregate could be significant. Future milestone payments, if any, will be reflected in our consolidated financial statements when the corresponding events have occurred. In addition, we may be required to pay significant royalties on future sales if products related to these arrangements are commercialized. Development and Commercialization Funding Arrangement with Blackstone Life Sciences (Blackstone) In March 2024, we entered into a development and commercialization funding arrangement with Blackstone, under which Blackstone has committed to providing up to $750 million in funding to us. This funding supports the development of our investigational mRNA-based influenza vaccine. Contingent upon regulatory approval in the U.S. and only if the approval is dependent on data from the funded activities, Blackstone will be entitled to receive low single-digit percentage royalties and up to $750 million in sales milestone payments. These payments are based on net sales of our future influenza and combination vaccines, with sales milestone payments contingent upon achieving specified cumulative net sales targets. Given the substantive transfer of financial risk to Blackstone, we account for this arrangement as an obligation to conduct research and development activities. The funding is recognized as a reduction to the expenses of our mRNA-based influenza program. This reduction is recognized proportionally as the related costs are incurred, based on an input method. For the three and six months ended June 30, 2026, we recorded expense reductions of $24 million and $74 million, respectively. For the three and six months ended June 30, 2025, we recorded research and development expense reductions of $160 million and $250 million, respectively.

In June 2016, we entered into a Collaboration and License Agreement, which was subsequently amended in 2018, with Merck & Co., Inc. (Merck) for the development and commercialization of individualized neoantigen therapy (INT), which has been assigned the generic name intismeran autogene.

In September 2022, Merck exercised its option for intismeran, including mRNA-4157, pursuant to the terms of the agreement and in October 2022 paid us an option exercise fee of $250 million. Following this exercise, the Merck Participation Term commenced. Pursuant to the agreement, we and Merck have agreed to collaborate on development and potential commercialization of intismeran, with costs and any profits or losses generally shared equally on a worldwide basis, subject to certain exceptions as outlined in the agreement. During the development phase, we are primarily responsible for process development and the manufacture of intismeran materials, while Merck generally leads clinical trials. We concluded that the collaboration arrangement under the Merck Participation Term is within the scope of ASC 808. For the three and six months ended June 30, 2026, we recognized expenses, net of Merck's reimbursements, of $97 million and $198 million, respectively, related to the INT collaboration under the Merck Participation Term. For the three and six months ended June 30, 2025, these expenses were $99 million and $203 million, respectively.

Additionally, for the three and six months ended June 30, 2026, the net cost recovery for capital expenditures was $1 million and $2 million, respectively. For the three and six months ended June 30, 2025, this amount was $6 million and $18 million, respectively. These amounts were applied to reduce the capitalized cost of the assets.

In January 2026, we entered into a collaboration agreement with Recordati S.p.A. (Recordati) to advance the development and commercialization of our investigational propionic acidemia therapeutic, mRNA-3927. Under the terms of the agreement, we granted Recordati an exclusive, royalty-bearing license to develop and commercialize the licensed product (mRNA-3927) worldwide, we will perform and continue to lead clinical development activities through approval, and Recordati will lead global commercialization upon approval. The transaction closed on March 16, 2026, and we received a $50 million upfront payment in the second quarter of 2026. The upfront payment is being recognized as collaboration revenue over time. In addition, we are eligible to receive up to $110 million in development and regulatory milestones, as well as additional commercial and sales milestones and tiered royalties on net sales.

We have other collaborative and licensing arrangements that we do not consider to be individually significant to our business at this time. Pursuant to these agreements, we may be required to make upfront payments and payments upon achievement of various development, regulatory and commercial milestones, which in the aggregate could be significant. Future milestone payments, if any, will be reflected in our consolidated financial statements when the corresponding events have occurred. In addition, we may be required to pay significant royalties on future sales if products related to these arrangements are commercialized.

In March 2024, we entered into a development and commercialization funding arrangement with Blackstone, under which Blackstone has committed to providing up to $750 million in funding to us. This funding supports the development of our investigational mRNA-based influenza vaccine. Contingent upon regulatory approval in the U.S. and only if the approval is dependent on data from the funded activities, Blackstone will be entitled to receive low single-digit percentage royalties and up to $750 million in sales milestone payments. These payments are based on net sales of our future influenza and combination vaccines, with sales milestone payments contingent upon achieving specified cumulative net sales targets.

Given the substantive transfer of financial risk to Blackstone, we account for this arrangement as an obligation to conduct research and development activities. The funding is recognized as a reduction to the expenses of our mRNA-based influenza program. This reduction is recognized proportionally as the related costs are incurred, based on an input method. For the three and six months ended June 30, 2026, we recorded expense reductions of $24 million and $74 million, respectively. For the three and six months ended June 30, 2025, we recorded research and development expense reductions of $160 million and $250 million, respectively.