AC Immune Stock Jumps After Alzheimer's Disease Vaccine Candidate Confirms Favorable Safety, Tolerability Profile

AC Immune SA ACIU has completed an 18-month interim assessment of safety and tolerability in the Phase 2 study evaluating ACI-24, its vaccine candidate for mild Alzheimer's disease (AD).
No safety concerns or evidence for CNS inflammation or ARIA (amyloid-related imaging abnormalities) were observed, confirming earlier interim results.
The company will complete the Phase 2 study with the 24-month analysis based on currently enrolled patients.
The company is also advancing an optimized ACI-24 formulation, which demonstrates enhanced and sustained immunogenicity in preclinical studies, particularly against key pathological forms of Abeta such as oligomeric and pyroglutamate Abeta.
Pyroglutamate Abeta (pyroGlu-Abeta) is a highly neurotoxic form of Abeta, that is N-terminally truncated and post-translationally modified to form pyroglutamate.
In non-human primates, vaccination with the optimized ACI-24 vaccine generated a strong, conformation-specific antibody response against oligomeric and pyroGlu-Abeta.
A robust boosting effect was also observed, approximately 8-fold vs. 4-fold increase, respectively, between the 3rd and 5th injections.
The company plans to file an Investigational New Drug (IND) application for the optimized ACI-24 formulation by year-end, followed by clinical development in Down syndrome-related AD, with Phase 2 as early as 2022/2023.
Price Action: ACIU shares are up 24.2% at $7.91 during the premarket session on the last check Wednesday.