Why did Biogen's EPS decline so sharply in Q1 2025 despite revenue growth?

The primary driver was a $165 million upfront payment to Stoke Therapeutics for the zorevunersen collaboration, which reduced both GAAP and Non-GAAP diluted EPS by approximately $0.95. Higher cost of sales from mix shift toward contract manufacturing and higher launch-related SG&A also weighed on margins, while other expense and a higher effective tax rate contributed to the GAAP decline.

Has Biogen changed its full-year 2025 guidance?

Yes, Non-GAAP diluted EPS guidance was revised to $14.50-$15.50 from $15.25-$16.25. The change reflects the roughly $0.95 Stoke upfront impact, partly offset by a $0.20 favorable foreign exchange benefit. Management said the underlying business outlook is unchanged, and revenue guidance of a mid-single-digit percentage decline at constant currency was maintained.

How is the MS franchise performing relative to newer products?

MS product revenue fell 11% to $953 million, reflecting ongoing erosion of established therapies. In contrast, rare disease revenue rose 33% to $563 million, driven by SPINRAZA and SKYCLARYS, and Alzheimer's collaboration revenue from LEQEMBI reached $33 million. Management expects further MS declines in 2025 to be partly offset by launch product growth.

What is Biogen's balance sheet and cash flow position?

As of March 31, 2025, Biogen held about $2.6 billion in cash and equivalents against roughly $6.3 billion in total debt, for net debt of about $3.7 billion. Q1 operating cash flow was $259 million, capital expenditures were $37 million, and free cash flow was $222 million, down from $507 million in Q1 2024.

Are tariffs a risk to Biogen's 2025 outlook?

Management said its 2025 guidance does not currently reflect a material impact from potential pharmaceutical tariffs. It cited that a significant share of U.S. revenue comes from products manufactured in the U.S. and that global inventory positions are favorable. However, management noted the tariff landscape remains uncertain and the guidance excludes any new tariffs.

BIIB 8-K: Earnings & Results

01—Abstract

Summary

Summary of the 8-K filed May 1, 2025. Cited figures are marked; the original filing is the authoritative source.

Biogen reported first quarter 2025 total revenue of $2.431 billion^a, up 6% year-over-year (8% at constant currency), with GAAP diluted EPS of $1.64 (down 39%) and Non-GAAP diluted EPS of $3.02 (down 18%).

The EPS decline is largely driven by a $165 million^b upfront payment to Stoke Therapeutics for rights to zorevunersen (Dravet syndrome), which reduced EPS by roughly $0.95. Product revenue grew only 1% at actual currency (3% at constant currency), aided partly by timing of SPINRAZA shipments. Multiple sclerosis revenue fell 11% to $953 million, while rare disease revenue rose 33% to $563 million, and launch products such as LEQEMBI, SKYCLARYS and ZURZUVAE showed growth.

Management updated full-year 2025 Non-GAAP diluted EPS guidance to $14.50^c-$15.50 from $15.25-$16.25, reflecting the Stoke payment partially offset by a $0.20 foreign exchange benefit. The company continues to expect total 2025 revenue to decline by a mid-single-digit percentage at constant currency, as MS erosion is expected to be partly offset by launch products. Management stated the outlook is not currently expected to be materially affected by potential pharmaceutical tariffs, citing U.S. manufacturing footprint and inventory positions, though the tariff landscape remains uncertain.

Balance sheet and cash flow remained solid, with Q1 operating cash flow of $259 million^d, free cash flow of $222 million, cash of $2.6 billion, total debt of $6.3 billion and net debt of about $3.7 billion. Pipeline news included a Phase 3 start for felzartamab in late antibody-mediated rejection, plans for additional felzartamab Phase 3 trials in 2025, FDA Fast Track designation for BIIB080, and full enrollment of the Phase 2b LUMA study for BIIB122 with readout expected in 2026.

02—Key points

Key Highlights

Q1 2025 total revenue of $2.43B rose 6% YoY (8% at constant currency), while product revenue grew just 1%, aided partly by SPINRAZA shipment timing.
GAAP diluted EPS fell 39% to $1.64 and Non-GAAP diluted EPS fell 18% to $3.02, mainly due to a $165M upfront payment to Stoke Therapeutics (about $0.95 per share).
MS product revenue declined 11% to $953M, while rare disease revenue grew 33% to $563M and launch products continued to gain traction.
Full-year 2025 Non-GAAP EPS guidance was lowered to $14.50-$15.50 from $15.25-$16.25, though underlying business outlook was described as unchanged; FX provided a $0.20 benefit.
Full-year 2025 total revenue is still expected to decline by a mid-single-digit percentage at constant currency versus 2024.
Management says 2025 outlook is not currently expected to be materially impacted by potential tariffs, given U.S. manufacturing presence and inventory positions.
Net debt of approximately $3.7B at quarter-end, with Q1 free cash flow of $222M, and pipeline milestones including felzartamab Phase 3 initiation and BIIB080 Fast Track designation.

03—Questions

Frequently Asked Questions

Why did Biogen's EPS decline so sharply in Q1 2025 despite revenue growth?
The primary driver was a $165 million upfront payment to Stoke Therapeutics for the zorevunersen collaboration, which reduced both GAAP and Non-GAAP diluted EPS by approximately $0.95. Higher cost of sales from mix shift toward contract manufacturing and higher launch-related SG&A also weighed on margins, while other expense and a higher effective tax rate contributed to the GAAP decline.
Has Biogen changed its full-year 2025 guidance?
Yes, Non-GAAP diluted EPS guidance was revised to $14.50-$15.50 from $15.25-$16.25. The change reflects the roughly $0.95 Stoke upfront impact, partly offset by a $0.20 favorable foreign exchange benefit. Management said the underlying business outlook is unchanged, and revenue guidance of a mid-single-digit percentage decline at constant currency was maintained.
How is the MS franchise performing relative to newer products?
MS product revenue fell 11% to $953 million, reflecting ongoing erosion of established therapies. In contrast, rare disease revenue rose 33% to $563 million, driven by SPINRAZA and SKYCLARYS, and Alzheimer's collaboration revenue from LEQEMBI reached $33 million. Management expects further MS declines in 2025 to be partly offset by launch product growth.
What is Biogen's balance sheet and cash flow position?
As of March 31, 2025, Biogen held about $2.6 billion in cash and equivalents against roughly $6.3 billion in total debt, for net debt of about $3.7 billion. Q1 operating cash flow was $259 million, capital expenditures were $37 million, and free cash flow was $222 million, down from $507 million in Q1 2024.
Are tariffs a risk to Biogen's 2025 outlook?
Management said its 2025 guidance does not currently reflect a material impact from potential pharmaceutical tariffs. It cited that a significant share of U.S. revenue comes from products manufactured in the U.S. and that global inventory positions are favorable. However, management noted the tariff landscape remains uncertain and the guidance excludes any new tariffs.

04—Continue

← View all 8-K filings