1Q26 Updates – All AβOut P2 Data Readout in Late 2026

Research evidence excerpt

1Q26 Updates – All AβOut P2 Data Readout in Late 2026

May 12, 2026

progression in the overall population measured via iADRS, the primary

endpoint of ALTITUDE-AD.

●During the call, mgmt stated that a “clear win” is 30% slowing

of disease progression.

●However, efficacy will depend on the population enrolled –

although the enrollment criteria for ALTITUDE-AD are similar

to the P3’s for lecanemab and donanemab, there were clear

differences in efficacy between subgroups (e.g., low vs. high tau,

APOE genotypes).

●Therefore, we will look at the totality of the data, including

patient baseline characteristics, subgroup analyses, and

movement of key biomarkers, when assessing the overall

efficacy at readout.

●ARIA-E incidence was favorable and points to sabirnetug’s broad

therapeutic index vs. approved anti-amyloid mAbs → differentiated

safety could enhance uptake, if approved.

●In the P1b INTERCEPT-AD study there was ~10% ARIA-E rate →

1/42 patients enrolled had symptomatic ARIA-E. This compares

to 24% ARIA-E rates for donanemab (6% symptomatic) and 13%

for lecanemab (~3% symptomatic).

●We would consider similar rates of ARIA-E (including

symptomatic) for sabirnetug from the INTERCEPT study as a

differentiator and a win on the safety front.

Enhanced Brain Delivery (EBD) → collaboration between ABOS and JCR to

improve drug delivery across the blood-brain barrier (BBB).

●Mgmt noted they have narrowed their candidate list and expect to

exercise their options on two candidates in 2Q26 → EBD IND targeted

for mid-2027.

●Key attributes driving candidate selection include broad brain

distribution, the potential for a wider safety margin, and

convenience of subQ dosing.

●Although early stage, the clinical development strategy would