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
This press release contains statements that constitute “forward-looking statements” within the meaning of Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934. Forward-looking statements are statements other than historical fact and may include statements that address future operating, financial or business performance or AC Immune’s strategies or expectations. In some cases, you can identify these statements by forward-looking words such as “may,” “might,” “will,” “should,” “expects,” “plans,” “anticipates,” “believes,” “estimates,” “predicts,” “projects,” “potential,” “outlook” or “continue,” and other comparable terminology. Forward-looking statements are based on management’s current expectations and beliefs and involve significant risks and uncertainties that could cause actual results, developments and business decisions to differ materially from those contemplated by these statements. These risks and uncertainties include those described under the captions “Item 3. Key Information – Risk Factors” and “Item 5. Operating and Financial Review and Prospects” in AC Immune’s Annual Report on Form 20-F and other filings with the Securities and Exchange Commission. Forward-looking statements speak only as of the date they are made, and AC Immune does not undertake any obligation to update them in light of new information, future developments or otherwise, except as may be required under applicable law. All forward-looking statements are qualified in their entirety by this cautionary statement.

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