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v3.25.2

Segment Information - Additional Segment Information (Details) - USD ($) $ in Millions | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2025 | Jun. 30, 2024 | Jun. 30, 2025 | Jun. 30, 2024
Segment Reporting, Asset Reconciling Item [Line Items] |  |  |  |
Total revenue | $ 2,645.5 | $ 2,464.9 | $ 5,076.5 | $ 4,755.4
Cost of sales, excluding amortization and impairment of acquired intangible assets | 605.0 | 546.0 | 1,234.3 | 1,088.2
Research and development: | 399.0 | 505.4 | 833.1 | 950.8
Acquired in-process research and development, upfront and milestone expense | 46.6 | 8.5 | 247.3 | 16.0
Selling, general and administrative | 583.8 | 553.8 | 1,156.3 | 1,135.3
Net income attributable to Biogen Inc. | 634.8 | 583.6 | 875.3 | 977.0
Product revenue, net |  |  |  |
Segment Reporting, Asset Reconciling Item [Line Items] |  |  |  |
Total revenue | 1,878.7 | 1,899.6 | 3,605.2 | 3,611.5
Royalty and other revenue |  |  |  |
Segment Reporting, Asset Reconciling Item [Line Items] |  |  |  |
Total revenue | 19.6 | 9.0 | 30.6 | 38.6
Reportable Segment |  |  |  |
Segment Reporting, Asset Reconciling Item [Line Items] |  |  |  |
Total revenue | 2,645.5 | 2,464.9 | 5,076.5 | 4,755.4
Other segment expense | 376.3 | 267.6 | 730.2 | 588.1
Net income attributable to Biogen Inc. | 634.8 | 583.6 | 875.3 | 977.0
Reportable Segment | Research and discovery |  |  |  |
Segment Reporting, Asset Reconciling Item [Line Items] |  |  |  |
Research and development: | 46.6 | 45.7 | 90.9 | 93.3
Reportable Segment | Early stage programs |  |  |  |
Segment Reporting, Asset Reconciling Item [Line Items] |  |  |  |
Research and development: | 51.9 | 66.6 | 124.3 | 150.7
Reportable Segment | Late stage programs |  |  |  |
Segment Reporting, Asset Reconciling Item [Line Items] |  |  |  |
Research and development: | 44.6 | 46.7 | 94.0 | 79.3
Reportable Segment | Marketed products |  |  |  |
Segment Reporting, Asset Reconciling Item [Line Items] |  |  |  |
Research and development: | 87.7 | 170.0 | 177.2 | 288.1
Reportable Segment | Other research and development costs |  |  |  |
Segment Reporting, Asset Reconciling Item [Line Items] |  |  |  |
Research and development: | 168.2 | 176.4 | 346.7 | 339.4
Reportable Segment | Product revenue, net |  |  |  |
Segment Reporting, Asset Reconciling Item [Line Items] |  |  |  |
Cost of sales, excluding amortization and impairment of acquired intangible assets | 415.0 | 358.4 | 877.2 | 736.1
Reportable Segment | Royalty and other revenue |  |  |  |
Segment Reporting, Asset Reconciling Item [Line Items] |  |  |  |
Cost of sales, excluding amortization and impairment of acquired intangible assets | $ 190.0 | $ 187.6 | $ 357.1 | $ 352.1

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