First Read Eisai Key takeaways from Biogen‘s AAIC event

Research evidence excerpt

First Read Eisai Key takeaways from Biogen‘s AAIC event

Global Research

14 July 2026ab

First Read

EquitiesEisai

Key takeaways from Biogen's AAIC event Japan

Pharmaceuticals

12-month rating Neutral

Biogen data are encouraging, but...

Biogen (covered by Michael Yee; report) hosted an AAIC event starting at 1:00am JST on 12m price target ¥4,600

15 July (slides), highlighting Phase 2 data for diranersen (BIIB080). Biogen’s share price

was down 8.6% as of noon ET on 14 July, compared with +0.2% for the S&P 500.

Price (14 Jul 2026) ¥4,376

Overall, we view the demonstration of a slowing in cognitive decline through tau

reduction as encouraging. However, given the lack of efficacy data for Eisai’s anti-MTBR RIC: 4523.T BBG: 4523 JP

tau antibody etalanetug, it will likely be difficult for investors to meaningfully Trading data and key metrics

incorporate its potential into the share price at this stage. Results from the Phase 2 study

52-wk range ¥5,322-3,723

of etalanetug in combination with Leqembi are expected in FY3/28, and Eisai could

Market cap. ¥1,235b/US$7.61b

potentially seek a development partner if the program advances into Phase 3.

Shares o/s 282m (ORD)

Diranersen, a tau antisense oligonucleotide (ASO) that suppresses upstream tau

production, demonstrated a 26% improvement in CDR-SB, a measure of cognitive Free float 94%

decline, at the 60mg Q24W dosing regimen (once every six months). This compares Avg. daily volume ('000) 1,698

indirectly with the reported 27% and 29% slowing of cognitive decline for the anti- Avg. daily value (m) ¥7,090.2

amyloid antibodies Leqembi (Eisai) and Kisunla (Eli Lilly), respectively. While the Common s/h equity (03/27E) ¥912b

mechanisms of action are different, the ability of diranersen to achieve a broadly P/BV (03/27E) 1.4x