AC Immune SA reported September 23 that its lead Parkinson's disease candidate ACI-7104 met primary safety, tolerability and immunogenicity endpoints in Part 1 of its Phase 2 VacSYn trial.
The Lausanne-based clinical-stage biotech enrolled 34 patients—25 receiving ACI-7104 and nine receiving placebo—and followed them through week 100. All patients who received the active vaccine developed antibodies against the target antigen after three immunizations, and antibody penetration into cerebrospinal fluid was observed across the board. The treatment demonstrated reactivity against aggregated species of alpha-synuclein, the protein implicated in neuron degeneration in Parkinson's.
Part 1 was not designed to evaluate biomarker or clinical outcomes. However, exploratory analyses identified trends suggesting an association between antibody levels and disease activity measures, and a signal was observed for total alpha-synuclein in cerebrospinal fluid that the company described as preliminary evidence consistent with target engagement.
AC Immune said the vaccine was generally safe and well-tolerated. The trial will continue with a two-year extension of Part 1, and the company plans to advance toward Part 2, which is designed to provide evidence of clinical activity to support a Phase 3 decision.
Expected meetings with the FDA on the final design of Part 2 are targeted for early 2027.
AC Immune also reiterated that it holds partnerships with pharmaceutical companies that carry potential milestone payments and royalties exceeding $4.5 billion.
Shares of AC Immune (NASDAQ: ACIU) were not traded at the time of publication.
