AC Immune Positive Interim Phase 2 Data on ACI-7104.056 Support Potential Slowing of Progression of Parkinson’s Disease

Core Insights - AC Immune SA announced positive interim results from the Phase 2 VacSYn trial for ACI-7104.056, an active immunotherapy targeting alpha-synuclein in early Parkinson's disease, indicating potential to slow disease progression [2][4][11] Interim Results - The VacSYn trial is a placebo-controlled, biomarker-based Phase 2 study involving 34 patients, with all participants treated for at least 12 months [5] - Interim results demonstrated that all target criteria for immunogenicity were met, with a 100% responder rate and a clear safety profile [6][10] - Antibody titers in serum were over 500-fold higher in the treatment group compared to placebo, indicating a robust immune response [7][8] Biomarker and Clinical Assessments - Disease-related biomarkers showed stabilization in the treatment group, including total CSF alpha-synuclein levels and neurofilament light chain (NfL) [12] - Clinical measures indicated a trend for stabilization of motor symptoms in the active treatment group, with no meaningful progression in MDS-UPDRS Part III scores [9][12] Expert Commentary - Dr. Andrea Pfeifer, CEO of AC Immune, emphasized the potential of ACI-7104.056 to transform Parkinson's disease treatment based on the interim data [4] - Dr. Werner Poewe highlighted the promising consistency of trends across multiple biomarkers and clinical assessments, suggesting beneficial effects on disease progression [4] Future Development Plans - Based on the interim results, AC Immune plans to seek regulatory feedback to accelerate the clinical development plan towards registration [11] - Final data from Part 1 of the VacSYn trial is expected in mid-2026 [11]