v3.25.3
Revenues
 9 Months Ended
Sep. 30, 2025
Revenue from Contract with Customer [Abstract]  
Revenues
Note 5:
Revenue
Product Revenue
Revenue by product is summarized as follows:
 For the Three Months Ended September 30,
20252024
(In millions)United
States		Rest of
World		TotalUnited
States		Rest of
World		Total
Multiple Sclerosis:
TECFIDERA$44.6 $123.6 $168.2 $40.1 $192.7 $232.8 
VUMERITY189.6 25.0 214.6 134.9 23.2 158.1 
Total Fumarate234.2 148.6 382.8 175.0 215.9 390.9 
AVONEX133.4 55.1 188.5 115.6 60.6 176.2 
PLEGRIDY27.8 30.6 58.4 27.9 33.4 61.3 
Total Interferon161.2 85.7 246.9 143.5 94.0 237.5 
TYSABRI247.5 184.3 431.8 227.5 178.6 406.1 
FAMPYRA(1)
— — — — 19.4 19.4 
Subtotal: Multiple Sclerosis642.9 418.6 1,061.5 546.0 507.9 1,053.9 
Rare Disease:
SPINRAZA153.2 220.8 374.0 153.1 228.3 381.4 
SKYCLARYS(2)
74.6 58.3 132.9 81.8 20.5 102.3 
QALSODY(3)
7.3 19.1 26.4 5.5 5.6 11.1 
Subtotal: Rare Disease235.1 298.2 533.3 240.4 254.4 494.8 
Biosimilars:
BENEPALI— 121.9 121.9 — 118.1 118.1 
IMRALDI— 52.6 52.6 — 54.1 54.1 
FLIXABI— 15.3 15.3 — 16.2 16.2 
BYOOVIZ2.0 5.0 7.0 4.1 3.9 8.0 
TOFIDENCE— — — 0.2 — 0.2 
Subtotal: Biosimilars2.0 194.8 196.8 4.3 192.3 196.6 
Other:
ZURZUVAE55.3 — 55.3 22.0 — 22.0 
Other(4)
— — — 0.3 1.8 2.1 
Subtotal: Other55.3 — 55.3 22.3 1.8 24.1 
Total product revenue, net$935.3 $911.6 $1,846.9 $813.0 $956.4 $1,769.4 
(1) Effective January 1, 2025, our collaboration and license agreement for FAMPYRA global commercialization rights was terminated.
(2) SKYCLARYS became commercially available in the E.U. during the first quarter of 2024.
(3) QALSODY became commercially available in the E.U. during the second quarter of 2024.
(4) Other includes FUMADERM and ADUHELM.
 For the Nine Months Ended September 30,
20252024
(In millions)United
States		Rest of
World		TotalUnited
States		Rest of
World		Total
Multiple Sclerosis:
TECFIDERA$131.6 $436.3 $567.9 $127.9 $611.4 $739.3 
VUMERITY494.7 71.0 565.7 385.0 66.4 451.4 
Total Fumarate626.3 507.3 1,133.6 512.9 677.8 1,190.7 
AVONEX363.7 169.3 533.0 344.0 193.5 537.5 
PLEGRIDY80.2 106.7 186.9 84.7 109.8 194.5 
Total Interferon443.9 276.0 719.9 428.7 303.3 732.0 
TYSABRI720.5 547.4 1,267.9 690.0 609.6 1,299.6 
FAMPYRA(1)
— 0.3 0.3 — 57.3 57.3 
Subtotal: Multiple Sclerosis1,790.7 1,331.0 3,121.7 1,631.6 1,648.0 3,279.6 
Rare Disease:
SPINRAZA456.9 733.7 1,190.6 458.9 692.9 1,151.8 
SKYCLARYS(2)
221.7 165.4 387.1 230.4 49.9 280.3 
QALSODY(3)
22.3 39.6 61.9 14.5 6.2 20.7 
Subtotal: Rare Disease700.9 938.7 1,639.6 703.8 749.0 1,452.8 
Biosimilars:
BENEPALI— 345.3 345.3 — 354.1 354.1 
IMRALDI— 146.7 146.7 — 162.1 162.1 
FLIXABI— 42.7 42.7 — 47.1 47.1 
BYOOVIZ8.7 15.8 24.5 18.1 9.2 27.3 
TOFIDENCE0.1 — 0.1 1.0 — 1.0 
Subtotal: Biosimilars8.8 550.5 559.3 19.1 572.5 591.6 
Other:
ZURZUVAE129.4 — 129.4 49.3 — 49.3 
Other(4)
0.4 1.7 2.1 2.0 5.6 7.6 
Subtotal: Other129.8 1.7 131.5 51.3 5.6 56.9 
Total product revenue, net$2,630.2 $2,821.9 $5,452.1 $2,405.8 $2,975.1 $5,380.9 
(1) Effective January 1, 2025, our collaboration and license agreement for FAMPYRA global commercialization rights was terminated.
(2) SKYCLARYS became commercially available in the E.U. during the first quarter of 2024.
(3) QALSODY became commercially available in the E.U. during the second quarter of 2024.
(4) Other includes FUMADERM and ADUHELM.
We recognized revenue from two wholesalers accounting for 27.8% and 16.0% of gross product revenue for the three months ended September 30, 2025, and 27.3% and 15.4% of gross product revenue for the nine months ended September 30, 2025.
We recognized revenue from two wholesalers accounting for 25.9% and 14.8% of gross product revenue for the three months ended September 30, 2024, and 25.6% and 12.9% of gross product revenue for the nine months ended September 30, 2024.
An analysis of the change in reserves for discounts and allowances is summarized as follows:
(In millions)DiscountsContractual
Adjustments		ReturnsTotal
Balance, December 31, 2024$162.7 $880.8 $48.1 $1,091.6 
Current provisions relating to sales in current year607.4 2,052.6 20.7 2,680.7 
Adjustments relating to prior years1.8 (82.0)1.0 (79.2)
Payments/credits relating to sales in current year(497.3)(1,271.1)(0.5)(1,768.9)
Payments/credits relating to sales in prior years(111.5)(479.2)(11.5)(602.2)
Balance, September 30, 2025$163.1 $1,101.1 $57.8 $1,322.0 
The total reserves above, which are included in our condensed consolidated balance sheets, are summarized as follows:
(In millions)As of September 30, 2025As of December 31, 2024
Reduction of accounts receivable$259.7 $154.1 
Component of accrued expense and other1,062.3 937.5 
Total revenue-related reserves$1,322.0 $1,091.6 
Revenue from Anti-CD20 Therapeutic Programs
Revenue from anti-CD20 therapeutic programs is summarized in the table below. For the purposes of this footnote, we refer to RITUXAN and RITUXAN HYCELA collectively as RITUXAN.
 For the Three Months Ended September 30,For the Nine Months Ended September 30,
(In millions)2025202420252024
Royalty revenue on sales of OCREVUS$386.4 $346.8 $1,029.0 $985.8 
Biogen’s share of pre-tax profits in the U.S. for RITUXAN, GAZYVA and LUNSUMIO101.0 94.8 292.4 285.3 
Other revenue from anti-CD20 therapeutic programs6.5 4.6 18.0 13.6 
Total revenue from anti-CD20 therapeutic programs$493.9 $446.2 $1,339.4 $1,284.7 
For additional information on our collaboration arrangements with Genentech, please read Note 19, Collaborative and Other Relationships, to these condensed consolidated financial statements.
Alzheimer's Collaboration Revenue
Alzheimer's collaboration revenue consists of our 50.0% share of LEQEMBI product revenue, net and cost of sales, including royalties, as we are not the principal. We began recognizing Alzheimer's collaboration revenue upon the accelerated approval of LEQEMBI in the U.S. during the first quarter of 2023.
For the three and nine months ended September 30, 2025, we recognized Alzheimer's collaboration revenue of approximately $42.7 million and $130.6 million, respectively, compared to $18.6 million and $33.2 million, respectively, in the prior year comparative periods.
For additional information on our collaboration arrangements with Eisai, please read Note 19, Collaborative and Other Relationships, to these condensed consolidated financial statements.
Contract Manufacturing, Royalty and Other Revenue
Contract manufacturing, royalty and other revenue is summarized as follows:
 For the Three Months Ended September 30,For the Nine Months Ended September 30,
(In millions)2025202420252024
Contract manufacturing revenue$141.5 $221.9 $648.8 $474.1 
Royalty and other revenue
9.7 9.7 40.3 48.3 
Total contract manufacturing, royalty and other revenue$151.2 $231.6 $689.1 $522.4 
Contract Manufacturing Revenue
Contract manufacturing revenue primarily reflects amounts earned under contract manufacturing agreements with our strategic customers and batches of LEQEMBI related to our collaboration with Eisai.
Royalty and Other Revenue
Royalty and other revenue primarily reflects royalty revenue on biosimilar products from our license arrangements with Samsung Bioepis and royalties we receive from net sales on products related to patents that we have out-licensed.
For additional information on our license arrangements with Samsung Bioepis and our collaboration arrangements with Eisai, please read Note 19, Collaborative and Other Relationships, to these condensed consolidated financial statements.