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Collaborative and Other Relationships (Tables) | 6 Months Ended
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Jun. 30, 2025
Organization, Consolidation and Presentation of Financial Statements [Abstract] |
Co Promotion Profit Sharing Formula | As a result of the FDA approval of LUNSUMIO our share of the combined annual co-promotion profits for RITUXAN and LUNSUMIO in excess of $50.0 million varies upon the following events, as summarized in the table below:
After LUNSUMIO Approval until the First Threshold Date | 37.5 | %
After First Threshold Date until the Second Threshold Date | 35.0 | %
After Second Threshold Date | 30.0 | %
Summary of Activity Related to BAN2401 and Elenbecestat Collaboration | A summary of development and sales and marketing expense related to the LEQEMBI Collaboration is as follows:
|  | For the Three Months Ended June 30, |  | For the Six Months Ended June 30,
(In millions) |  | 2025 |  | 2024 |  | 2025 |  | 2024
Total development expense incurred by the collaboration related to the advancement of LEQEMBI |  | $ | 54.9 |  |  | $ | 90.6 |  |  | $ | 107.5 |  |  | $ | 177.9 |
Biogen's share of the LEQEMBI Collaboration development expense reflected in research and development expense in our condensed consolidated statements of income |  | 27.5 |  |  | 45.4 |  |  | 53.8 |  |  | 89.0 |
Total sales and marketing expense incurred by the LEQEMBI Collaboration |  | 171.2 |  |  | 137.7 |  |  | 348.9 |  |  | 311.6 |
Biogen's share of the LEQEMBI Collaboration sales and marketing expense reflected in selling, general and administrative expense in our condensed consolidated statements of income |  | 85.7 |  |  | 68.9 |  |  | 174.5 |  |  | 155.8 |
Summary of activity related to the UCB collaboration | A summary of development expense related to the UCB collaboration agreement is as follows:
|  | For the Three Months Ended June 30, |  | For the Six Months Ended June 30,
(In millions) |  | 2025 |  | 2024 |  | 2025 |  | 2024
Total UCB collaboration development expense |  | $ | 17.8 |  |  | $ | 16.5 |  |  | $ | 39.6 |  |  | $ | 33.1 |
Biogen's share of UCB collaboration development expense reflected in research and development expense in our condensed consolidated statements of income |  | 8.9 |  |  | 8.3 |  |  | 19.8 |  |  | 16.6 |
Summary of Activity Related to Sage Therapeutics | A summary of development and sales and marketing expense related to the Sage collaboration is as follows:
|  | For the Three Months Ended June 30, |  | For the Six Months Ended June 30,
(In millions) |  | 2025 |  | 2024 |  | 2025 |  | 2024
Total Sage collaboration development expense |  | $ | 1.5 |  |  | $ | 9.6 |  |  | $ | 3.9 |  |  | $ | 21.2 |
Biogen's share of Sage collaboration development expense reflected in research and development expense in our condensed consolidated statements of income |  | 0.8 |  |  | 4.8 |  |  | 2.0 |  |  | 10.6 |
Total sales and marketing expense incurred by the Sage collaboration |  | 45.7 |  |  | 26.9 |  |  | 89.2 |  |  | 54.5 |
Biogen's share of Sage collaboration sales and marketing expense reflected in selling, general and administrative expense and collaboration profit sharing/(loss reimbursement) in our condensed consolidated statements of income |  | 22.9 |  |  | 13.5 |  |  | 44.6 |  |  | 27.3 |
Summary of Activity Related to Denali Therapeutics Collaboration | A summary of development expense related to the Denali collaboration is as follows:
|  | For the Three Months Ended June 30, |  | For the Six Months Ended June 30,
(In millions) |  | 2025 |  | 2024 |  | 2025 |  | 2024
Total Denali collaboration development expense |  | $ | 12.1 |  |  | $ | 15.4 |  |  | $ | 24.9 |  |  | $ | 29.6 |
Biogen's share of Denali collaboration development expense reflected in research and development expense in our condensed consolidated statements of income |  | 7.2 |  |  | 9.3 |  |  | 14.9 |  |  | 17.8 |
Summary of Activity Related to Stoke Therapeutics Collaboration | A summary of development expense related to the Stoke collaboration agreement is as follows:
(In millions) |  | For the Three Months Ended June 30, 2025 |  |  |  | For the Six Months Ended June 30, 2025 |  |
Total Stoke collaboration development expense |  | $ | 8.9 |  |  |  |  | $ | 12.8 |  |  |
Biogen's share of Stoke collaboration development expense reflected in research and development expense in our condensed consolidated statements of income |  | 2.6 |  |  |  |  | 3.8 |  |  |

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