ACI-7104

Swiss biotech AC Immune, researching immunological treatments for neurodegenerative disorders, reported interim Parkinson’s disease data Thursday, suggesting it may slow the progression of the condition. But the interpretation of its clinical endpoints remains unclear, particularly for the measurement the FDA typically uses to approve or reject new Parkinson’s drugs, known as the MDS-UPDRS. The data come from a small trial of about 34 patients who were randomized 3-to-1 to receive AC Immune’s drug, called ACI-7104. AC Immune said ACI-7104 increased Parkinson’s-relevant immune responses and stabilized a handful of biomarkers, most importantly alpha-synuclein. The biomarker is thought to build up into toxic protein clumps in the brain and nervous system, leading to the hallmark symptoms of neurodegeneration. But drugmakers have seen little success in targeting alpha-synuclein, especially for Parkinson’s disease — programs from Roche and Novartis-UCB both failed Phase 2 tests last year. In AC Immune’s trial, patients who received ACI-7104 saw antibody titers “several hundred-fold higher” than the placebo group for the antigen that targets alpha-synuclein after 76 weeks. That change in antibody titers, when compared to a patient’s baseline in their cerebrospinal fluid, was statistically significant. AC Immune said the p-values at both week 24 and week 76 were p<0.05. The theory behind AC Immune’s drug is that it can potentially boost the body’s immune response to the clumps of built-up alpha-synuclein. The antibodies then attack those clumps, leading to stabilization of disease. AC Immune’s stock $ACIU was up by as much as 10% at market open Thursday. Whether this increase translates into a clinical benefit remains to be seen. Though AC Immune measured patients’ changes in the MDS-UPDRS, researchers did not power their analysis for statistical significance. AC Immune did report that patients who took ACI-7104 saw their MDS-UPDRS scores increase by about two to three points, roughly as expected in early Parkinson’s disease. Scores fell slightly after 12 weeks, were flat after 24 weeks, and ticked slightly higher by week 76. The company said that amounted to a stabilization of disease, even though MDS-UPDRS scores rose. AC Immune did not report specific MDS-UPDRS scores, but showed patient progression over time on a graph in their investor presentation Thursday morning. Patients in the placebo group saw their MDS-UPDRS scores rise by more than five points. The company says it plans to launch the next part of the trial “as soon as possible” and will report final data from this part of the study in mid-2026. AC Immune will also seek to discuss the future clinical development plan with regulators.