AC Immune Shares Phase 1b/2 ABATE Trial Safety Data for ACI-24.060 in Down Syndrome

AC Immune SA, based in Lausanne, Switzerland, has shared promising interim results from its ABATE Phase 1b/2 trial concerning the investigational drug ACI-24.060, developed for individuals with Down syndrome (DS). This trial, which focuses on the safety and tolerability of the drug, aims to target harmful forms of amyloid beta (Abeta), a peptide implicated in the development of Alzheimer's disease (AD).

The trial revealed that participants from the first two cohorts, who received either low or mid doses of ACI-24.060, have not experienced any serious adverse reactions over a treatment period of up to one year. Moreover, there have been no reports of amyloid-related imaging abnormalities (ARIA), a known complication in similar therapeutic approaches.

Dr. Anke Post, AC Immune's Chief Medical Officer, expressed optimism about these findings, suggesting that ACI-24.060 holds promise as a novel treatment option for those with Down syndrome, addressing brain Abeta pathology with an initially favorable safety profile.

The ABATE study, registered under ClinicalTrials.gov Identifier NCT05462106, operates as a randomized, double-blind, placebo-controlled trial. Its objective is to evaluate the safety, tolerability, immunogenicity, and pharmacodynamic effects of ACI-24.060 in both prodromal Alzheimer's disease and non-demented adults with DS. This study design facilitates concurrent research in these two groups, given their potential risk of developing Alzheimer's due to shared Abeta pathology.

Dr. Mike Rafii, a renowned expert in neurology and the study's Coordinating Principal Investigator, emphasized the importance of safety in the DS population. He noted the urgent need for treatments that address amyloid pathology to hinder the onset and progression of Alzheimer's disease, highlighting the encouraging safety profile of ACI-24.060 so far.

The drug has garnered Fast Track status from the U.S. FDA for its application in treating Alzheimer's disease. Previous reports indicated positive interim results regarding the drug's safety, tolerability, and immunogenicity in Alzheimer's cohorts, supporting its application in DS patients within the ABATE trial. The trial now expands to assess the effects of higher doses of ACI-24.060, with recruitment efforts ongoing in the United States, United Kingdom, and Spain.

The ABATE study's structure as a multicenter, adaptive, double-blind, randomized, placebo-controlled trial allows critical evaluation of ACI-24.060 across different doses and regimens in both Alzheimer's and DS populations. A key requirement for participation is confirmation of brain Abeta pathology through positron emission tomography (PET) scans. PET imaging has been recognized as a valid surrogate marker of efficacy for disease-modifying therapies targeting Abeta, based on recent studies and FDA endorsements.

Individuals with DS who are aged between 35 and 50 and are interested in participating can find additional information on the ABATE Study website.

Within the Down syndrome community, there exists a heightened predisposition to developing Alzheimer's-related symptoms due to an extra copy of chromosome 21, which houses the gene responsible for amyloid-precursor protein (APP) production. This leads to an overproduction of APP, causing Abeta plaque accumulation. The ABATE trial seeks to elucidate whether ACI-24.060 can effectively target early-stage brain Abeta, potentially offering this population a vital therapeutic option.

ACI-24.060, derived from AC Immune's SupraAntigen® platform, is designed to elicit a robust polyclonal antibody response against key pathological Abeta forms. This investigational drug aims to enhance protective antibody formation while demonstrating safety and tolerability consistent with previous ACI-24 trials. The therapy could potentially inhibit plaque formation and promote clearance, thereby mitigating further disease progression.

AC Immune SA stands as a leading entity in developing precision therapeutics for neurodegenerative diseases, leveraging its clinically validated SupraAntigen® and Morphomer® platforms. The company's robust pipeline includes a range of therapeutic and diagnostic initiatives, supported by strategic global pharmaceutical partnerships and significant non-dilutive funding.