AC Immune wins FDA Fast Track and IND clearance for Parkinson's candidate ACI-7104

AC Immune SA said on August 11, 2026 that the FDA granted Fast Track designation and cleared an Investigational New Drug application for ACI-7104, its wholly owned anti-alpha-synuclein active immunotherapy candidate for early-stage Parkinson's disease¹. The company said the clearance means the ongoing Phase 2 VacSYn study can add sites in the United States.

ACI-7104 is designed to induce a-syn-specific antibodies, preferentially recognizing aggregated a-syn species that are toxic to neurons¹. The drug is being tested in VacSYn, an adaptive, biomarker-based Phase 2 trial in patients with early-stage Parkinson's disease¹, and the company said final week-100 data from Part 1 remains on track for release in the second half of 2026.

The FDA action followed interim results from Part 1 of the trial reported at the 76-week mark. According to the company, ACI-7104 was safe and well tolerated, with no clinically relevant safety issues being reported, and targets were also met for immunogenicity with a 100% responder rate.¹

AC Immune also said it had received a $4 million grant from the Vijay and Marie Goradia Charitable Foundation, which the company said will fund extension of Part 1 of the VacSYn trial, enabling the assessment of long-term safety and efficacy of ACI-7104 for an additional two years¹.

Interim CEO Martin Zügel called the Fast Track designation and IND clearance important achievements for the program given the unmet need in Parkinson's disease, according to the release. Günther Staffler, Executive Vice President of Development, said the FDA decision reflects the growing importance of the program and that the company expects to report full Part 1 results in the coming months.