AC Immune shares rise 14.70% after-hours after positive Phase 2 data for ACI-7104.056 shows potential to slow Parkinson’s progression via alpha-synuclein immunotherapy.

AC Immune surged 14.70% in after-hours trading following the release of positive interim Phase 2 data for its Parkinson’s disease immunotherapy ACI-7104.056. The trial demonstrated that targeting alpha-synuclein (a-syn) pathology with the active immunotherapy stabilized disease-related biomarkers, including cerebrospinal fluid a-syn levels and neurofilament light chain (NfL), while clinical motor function assessments suggested disease stabilization. The treatment exhibited a 100% responder rate in immunogenicity and a favorable safety profile, with no serious adverse events reported. These results, described as the first evidence of active immunotherapy slowing Parkinson’s progression, prompted the company to seek regulatory feedback to accelerate development toward potential registration. The data align with AC Immune’s focus on precision immunotherapies for neurodegenerative diseases and underscore the therapeutic’s potential to transform Parkinson’s treatment.