AC Immune Wins FDA Fast Track for Parkinson's Vaccine-Style Therapy ACI-7104

AC Immune (Nasdaq: ACIU) has received FDA Fast Track designation for ACI-7104, its investigational anti-alpha-synuclein active immunotherapy for early Parkinson's disease, the company said Tuesday. The designation — alongside FDA clearance of the company's investigational new drug application, which allows the ongoing Phase 2 VacSYn trial to expand to US clinical sites — marks an important step toward a potential disease-modifying treatment for Parkinson's, a disease currently managed mostly with symptom-relief therapies.

Teaching the Immune System to Clear Toxic Protein

ACI-7104 is a vaccine-style active immunotherapy designed to prompt the body's own immune system to generate antibodies against misfolded alpha-synuclein, the protein whose aggregation in the brain is a hallmark of Parkinson's. Unlike therapies that address symptoms, it is being studied as a disease-modifying candidate. AC Immune previously reported interim 76-week data from Part 1 of the Phase 2 VacSYn study showing ACI-7104 was safe and generally well tolerated, with a 100 percent immunogenicity response rate — and the optimized ACI-7104.056 formulation generated anti-alpha-synuclein antibody levels averaging 16 times higher than placebo after three immunizations.

The company expects to report full 100-week data from Part 1 of the Phase 2 trial in the second half of 2026, and plans to extend the study for two additional years to evaluate long-term safety and potential efficacy. "This is an area where a disease-modifying therapy would transform patient care," analysts at PRISM MarketView noted, though they cautioned that immune response data do not yet establish clinical benefit. The Fast Track designation allows for more frequent FDA interactions and rolling submission of a potential biologics license application.