AC Immune SA announced that it has received Fast Track designation from the U.S. Food and Drug Administration (FDA) for its wholly-owned anti-amyloid beta (Abeta) active immunotherapy (vaccine)-candidate, ACI-24.060, for treatment of Alzheimer's disease. This follows FDA clearance of the Investigational New Drug (IND) application enabling expansion to the USA of the ongoing Phase 1b/2 ABATE study of ACI- 24.060 in patients with AD and individuals with DS. Furthermore, the first individual with DS has been dosed in ABATE.

This regulatory progress underscores the attraction of an active immunotherapy targeting toxic species of Abeta. By inducing a polyclonal response including antibodies against both oligomeric Abeta and pyroglutamate-Abeta, ACI-24.060 targets the same toxic species as disease modifying anti-Abeta monoclonal antibodies that slowed AD progression in Phase 3 clinical trials. As ACI-24.060, created using our SupraAntigen(R) platform, specifically targets the most toxic forms of Abeta, we believe it may offer best-in-class efficacy with all the potential advantages in safety, administration and distribution that can be expected from a vaccine.

We look forward to showing in first half 2024 the effect of ACI-24.060 on amyloid plaque reduction, a surrogate marker for disease modification. The ABATE study is a Phase 1b/2, multicenter, adaptive, double-blind, randomized, placebo-controlled study to assess the safety, tolerability, immunogenicity, and pharmacodynamic effects of ACI-24.060 in subjects with prodromal Alzheimer's disease and in adults with Down syndrome. All participants in the trial must have brain Abeta pathology confirmed by a positron emission tomography (PET) scan.

Recent clinical studies and FDA approvals have validated Abeta as a disease modifying therapeutic target in AD and are supportive of Abeta PET imaging as a surrogate marker of efficacy. The trial begins with a dose escalation phase in AD patients, during which various doses/dosing regimens may be evaluated, and also includes individuals with DS. About AD in Down syndrome Individuals with Down syndrome (DS) have a third copy of all or part of chromosome 21, which contains the gene that codes for amyloid-precursor protein (APP).

Overproduction of APP is believed to cause the accumulation of Abeta plaques. Virtually all individuals with DS will develop Abeta plaques and AD(1), with DS-related AD sharing a similar pathophysiology and biomarkers with other forms of genetic AD. Given the more predictable onset and progression of symptoms in DS-related AD, AC Immune believes ABATE's results will offer crucial insights into the ability of ACI-24.060 active immunotherapy to modulate neurodegeneration at its earliest stages and offer this population a much needed therapeutic option.