Minter Reiterates Buy on Biogen as Tau-Targeting Diranersen Data Signals Clinically Meaningful Cognitive Benefit and Strong Biomarker Validation

William Blair analyst Myles Minter has reiterated their bullish stance on BIIB stock, giving a Buy rating today.

Myles Minter has given his Buy rating due to a combination of factors tied to Biogen’s emerging Alzheimer’s portfolio, particularly the CELIA trial of the tau‑targeting antisense therapy diranersen. Although the study technically missed its primary dose‑response endpoint on CDR‑SB at week 76, he views the consistent slowing of cognitive decline across all doses—especially the lowest, infrequently dosed regimen—as a clinically meaningful signal that likely approaches the efficacy range seen with leading anti‑amyloid agents.

Minter also highlights that robust biomarker effects, including reductions in CSF tau and neurofibrillary tangle pathology, validate the drug’s intracellular tau knockdown mechanism and differentiate it from extracellular antibody approaches. With Biogen preparing to advance BIIB080 into registrational trials and the market already reacting positively despite limited detail before the full AAIC 2026 presentation, he sees the risk‑reward profile as attractive and supportive of a continued Buy recommendation on BIIB.

In another report released today, TD Cowen also maintained a Buy rating on the stock with a $215.00 price target.