BIIB - A Breakthrough for Tau: CELIA Results Support Diranersen's Advancement to Registrational Development in Alzheimer's Disease

Research evidence excerpt

BIIB - A Breakthrough for Tau: CELIA Results Support Diranersen's Advancement to Registrational Development in Alzheimer's Disease

FLASH NOTE

May 14, 2026

Yatin Suneja yatin.suneja@guggenheimpartners.com BIIB - A Breakthrough for Tau: CELIA Results

212 518 9565 Support Diranersen's Advancement to Registrational

Delma Caiati, M.D., Ph.D.

delma.caiati@guggenheimpartners.com Development in Alzheimer's Disease

617 859 4606

Eddie Hickman, Ph.D. Key Message: Following CELIA's positive news, we caught up with BIIB mgmt

eddie.hickman@guggenheimpartners.com who sounded very confident on the strength of the totality of the results supporting 212 518 9904

advancement of diranersen (BIIB080), their first-in-class anti-tau ASO in early

Min Lee, Ph.D. Alzheimer's disease, to Phase 3. Notably, this represents the first evidence from

min.lee@guggenheimpartners.com a randomized Phase 2 study that reducing tau may meaningfully impact AD 212 823 6744 progression. Pre-specified analyses demonstrated slowing of clinical decline across

Iris Gao, Ph.D. ALL studied doses, with robust reductions in both CSF tau and tau PET biomarkers

iris.gao@guggenheimpartners.com maintained throughout the 18-month study, consistent with Phase 1b (placebo also within

212 518 9013 historical range). The study did miss its primary endpoint - we had highlighted this was

a PoC study designed for dose-response (see our deep-dive HERE) - and the fact

that the strongest cognitive benefit was observed at the lowest dose (60mg Q24W)

BIIB maderesponseinherentlyframework.more However,challengingthethefactachievementthat both ofbiomarkerstatistical significanceand clinicalinbenefitsa dose-

Biogen Inc. were seen across all doses strengthens the robustness of the overall findings.