Biogen Has Quietly Rebuilt Its Growth Engine While the Market Argued About Alzheimer's

For most of the past three years the investment case for Biogen was an argument about a single molecule. Would lecanemab — marketed as LEQEMBI, the anti-amyloid antibody it commercializes with Eisai — become the blockbuster that redeemed a company whose multiple sclerosis franchise was eroding under generics and biosimilars? That framing was always too narrow, and the first quarter of 2026 is where it broke.

Biogen reported total revenue of $2.48 billion, up 2% year-over-year, with GAAP diluted EPS of $2.15 and non-GAAP diluted EPS of $3.57, the latter up 18% . Underneath that flat-looking top line, the portfolio of products management designates as "growth products" — its LEQEMBI collaboration share plus SKYCLARYS, QALSODY, ZURZUVAE, VUMERITY and SPINRAZA — grew 12% to $851 million and, for the first time, out-earned the remaining MS book . The stock has responded: shares closed at $199.15 on July 10, up roughly 50% over the past year and pressing against a 52-week high of $219.72, having troughed near $121 last summer . The debate is no longer whether Biogen can find growth. It is whether the growth is durable enough, and the balance sheet flexible enough, to justify paying up for a company that spent half a decade in decline.

My view is that the market is still underpricing the near-term setup, and that the reason is a mix of stale pattern-matching on the MS decline and an over-focus on binary pipeline events that obscures a business already inflecting. Three things carry that case: the growth portfolio is compounding at a rate that has changed the arithmetic of the whole company; the closed Apellis acquisition adds not just revenue but a commercial platform in nephrology and ophthalmology that de-risks the most valuable Phase 3 asset in the pipeline; and the balance sheet is being managed toward a clear 2027 deleveraging target that the accretion math actually supports. Against that, the genuine risk is a cluster of late-2026 and 2027 clinical readouts where a company...