Why Are Biogen Shares Gaining Today?

Biogen Inc BIIB and Eisai Co Ltd ESALY have new data released for Aduhelm (aducanumab-avwa) in Alzheimer's disease.
Related: Biogen Posts Just $300K Sales From Aduhelm In Q3, Though Earnings Beat Estimates.
The analysis comes from approximately 7,000 plasma samples from more than 1,800 patients in Phase 3 trials.
According to new data released, Aduhelm lowers levels of a second protein that accumulates in the brains of people with the disease.
Biogen said its Phase 3 studies found that Aduhelm significantly lowered blood levels of an abnormal form of the protein tau - another target of experimental Alzheimer's drugs.
The Company said that the tau levels were correlated to changes in amyloid plaques and slowed the cognitive and functional decline.
In one trial, tau levels in patients with early Alzheimer's given the highest dose of Aduhelm fell 13%, compared with an increase of 8% for placebo patients.
In the second trial, high-dose patients saw tau levels decrease 16%, while levels in the placebo group rose 9%.
Related Link: Eisai Posts New Lecanemab Data From Mid-Stage Alzheimer's Trial.
Price Action: BIIB shares are up 3.54% at $276 during the premarket session on the last check Friday.