Tau still intrigues, but BIIB080 faces high bar at AAIC; our final thoughts

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Tau still intrigues, but BIIB080 faces high bar at AAIC; our final thoughts

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Biogen Inc.

Tau still intrigues, but BIIB080 faces high

bar at AAIC; our final thoughts

Maintain Rating: NEUTRAL | PO: 217.00 USD | Price: 199.15 USD

Given uncertainties, AAIC unlikely to settle debate 13 July 2026

In an Alzheimer’s field frustrated by repeated setbacks, BIIB080/ diranersen’s arguably Equity

messy topline added another wrinkle vs. deliver a clear step forward (see our topline

takes). Ahead of tomorrow’s AAIC presentation of the full phase 2 CELIA dataset, we JasonResearchZemanskyAnalyst

spoke with our KOLs and surveyed 15 prescribers to identify key questions and relevant BofAS

benchmarks. Ultimately, while tau is compelling enough to drive volatility, we don’t get +1jason.zemansky@bofa.com646 855 4280

the sense the details are likely to materially change the tau story or broader Biogen Jacqueline Plesset

debate given the entirety of the debate. Below, we flag issues we think matter most, Research Analyst

BofAS

with a checklist (page 4) to help parse the readout. Maintain Neutral, $217 PO. +1 646 855 0014

Totality of evidence, not one endpoint, needed for a win jacqueline.plesset@bofa.com

While our inbounds have centered on CDR-SB and tau PET, KOLs largely agreed the

readout will be judged on the totality of evidence given the topline and historical Stock Data

context. Although tau has long been viewed as a more compelling target, even

supporters were troubled by the inverse dose response and cautioned mixed results Price 199.15 USD

would likely invite the same concerns weighing on abeta mAb’s uptake. With intrathecal Price Objective 217.00 USD

administration further raising the commercial barrier, we think a “win” requires 1) Date Established 8-Jul-2026