Biogen tops estimates on rare disease strength, cuts full-year guidance

US biotech major Biogen (Nasdaq: BIIB) reported stronger-than-expected earnings for the first quarter of 2025, helped by surging sales of its rare disease portfolio, even as revenue from its multiple sclerosis franchise continued to decline.

Revenue rose 6% year-on-year to $2.43 billion, beating Wall Street expectations of $2.23 billion. Non-GAAP diluted earnings per share came in at $3.02, well above the consensus estimate of $2.52, while GAAP diluted EPS dropped to $1.64 from $2.70 a year earlier, reflecting a $165 million upfront payment related to a new licensing deal.

The company’s rare disease business, led by Skyclarys (omaveloxolone) and Spinraza (nusinersen), delivered a 33% sales increase to $563 million. In contrast, revenue from Biogen’s multiple sclerosis products dropped 11% to $953 million, underlining the continued erosion of this once-core franchise.