AC Immune Reports Further Positive Interim Results from Phase 2 Trial of ACI-7104.056 Active Immunotherapy in Early Parkinson’s Disease

AC Immune Reports Further Positive Interim Results from Phase 2 Trial of ACI-7104.056 Active Immunotherapy in Early Parkinson’s Disease

• Active immunotherapy with ACI-7104.056 induces high anti-a-synuclein (a-syn) antibody levels on average over 20-fold higher than placebo after 4 immunizations
• Repeated immunizations amplify the anti-a-syn antibody response, supporting boostability and the potential to further increase antibody titers
• ACI-7104.056 is well tolerated with no safety issues reported to date

Lausanne, Switzerland, April 2, 2025 – AC Immune SA (NASDAQ: ACIU), a clinical-stage biopharmaceutical company pioneering precision therapeutics for neurodegenerative diseases, today announced additional interim safety and positive immunogenicity data from the Phase 2 VacSYn clinical trial evaluating ACI-7104.056, its wholly owned anti-alpha-synuclein (a-syn) active immunotherapy candidate, for the treatment of patients with early Parkinson’s disease (PD).

Dr. Andrea Pfeifer, CEO of AC Immune SA, commented: “We continue to be encouraged by the data emerging from the Phase 2 VacSYn trial of ACI-7104.056 active immunotherapy in early Parkinson’s disease. These additional interim safety and immunogenicity data after 6 months of treatment underscore the good safety profile and reinforce the best-in-class characteristics of ACI-7104.056 for the treatment of Parkinson’s disease. We look forward to sharing further updates later in 2025.”

VacSYn is an adaptive, placebo-controlled, and biomarker-based Phase 2 study in patients with early PD, consisting of two parts with a seamless transition. Part 1 includes initial analyses from over 30 patients randomized to receive ACI-7104.056 or placebo at a ratio of 3:1. To date, in the blinded, pooled active and placebo groups, no serious adverse event considered related to the study drug has been reported. The most common adverse events are mild and transient injection site reactions and headaches, generally of mild severity.

Interim results show positive antibody responses were effectively induced against the target antigen at week 6 after 2 immunizations and were further boosted by each additional immunization. Treatment with ACI-7104.056 induced an increase in anti-a-syn antibodies on average over 20-fold higher than the placebo background level after four immunizations.

Based on further interim results to be reported later in 2025 including pharmacodynamic and biomarker data, AC Immune may decide to initiate Part 2 of VacSYn with up to 150 patients. Further exploratory endpoints for patients in Part 2 will include the evaluation of the progression of motor and non-motor symptoms of the disease, as well as digital, imaging, and fluid biomarkers. The aim is to establish early proof-of-concept and identification of disease-specific biomarkers for rapid transition into a pivotal study.

About ACI-7104.056
ACI-7104.056 is an optimized formulation of its clinically validated anti-a-syn predecessor active immunotherapy which generated a target-specific antibody response against pathological oligomeric a-syn to inhibit spreading and downstream neurodegeneration in early Parkinson’s disease. The accumulation of alpha-synuclein protein aggregates has been shown to cause inflammatory stress in cells and contribute to the degeneration of neurons in the brain. It has been known to play a key role in the development of neurodegenerative diseases such as Parkinson’s Disease. Previous clinical studies showed the predecessor candidate produced a strong and boostable antibody response with evidence of target engagement and a signal of clinical efficacy.

About AC Immune SA
AC Immune SA is a clinical-stage biopharmaceutical company and a global leader in precision prevention for neurodegenerative diseases, including Alzheimer’s disease, Parkinson’s disease, and NeuroOrphan indications driven by misfolded proteins. The Company’s two clinically validated technology platforms, SupraAntigen® and Morphomer®, fuel its broad and diversified pipeline of first- and best-in-class assets, which currently features a range of therapeutic and diagnostic programs, including candidates in Phase 2 and Phase 3 development. AC Immune has a strong track record of securing strategic partnerships with leading global pharmaceutical companies, resulting in substantial non-dilutive funding to advance its proprietary programs and >$4.5 billion in potential milestone payments plus royalties.

SupraAntigen® is a registered trademark of AC Immune SA in the following territories: AU, EU, CH, GB, JP, RU, SG and USA. Morphomer® is a registered trademark of AC Immune SA in CN, CH, GB, JP, KR, NO and RU.

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Forward looking statements
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