CAMBRIDGE, Mass., July 14, 2026
ProMIS Neurosciences presented the first human evidence that its investigational Alzheimer’s disease therapy PMN310 achieves dose-dependent reduction of amyloid-beta oligomers (AβOs) in cerebrospinal fluid (CSF), marking an important milestone in the clinical development of its precision monoclonal antibody. The findings, presented at the Alzheimer’s Association International Conference (AAIC) 2026, were generated from the company’s Phase 1a trial in healthy volunteers and represent one of the first quantitative demonstrations of treatment-related amyloid-beta oligomer reduction in humans. The company also confirmed it remains on track to report blinded six-month interim data from the ongoing PRECISE-AD Phase 1b trial in the coming weeks.
Phase 1 Study Demonstrates Dose-Dependent Target Engagement
Analysis of CSF samples collected from the Phase 1a study showed that participants receiving PMN310 experienced dose-dependent reductions in detectable amyloid-beta oligomers at both three and 29 days after a single intravenous dose. Measurements were performed using the highly sensitive surface-based fluorescence intensity distribution analysis (sFIDA) assay developed by attyloid GmbH. Although healthy volunteers naturally carry lower oligomer levels than Alzheimer’s patients, the measurable decline provides direct pharmacodynamic evidence that PMN310 successfully crossed into the central nervous system and engaged its intended therapeutic target.
Selective Oligomer Targeting May Improve Safety Profile
Additional data presented at AAIC highlighted PMN310’s selective mechanism of action. Laboratory studies demonstrated strong binding to toxic amyloid-beta oligomers without binding to amyloid-beta monomers, plaques, or vascular amyloid deposits. This highly selective profile is designed to preserve efficacy while potentially reducing the risk of amyloid-related imaging abnormalities (ARIA) commonly associated with plaque-targeting Alzheimer’s antibodies. The Phase 1a trial also showed favorable pharmacokinetics, with CSF drug concentrations substantially exceeding estimated oligomer levels, a CSF half-life of approximately 27 days, and good overall tolerability.
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Phase 1b PRECISE-AD Trial Continues Toward Key Readouts
ProMIS has completed enrollment of 144 patients in the randomized, placebo-controlled PRECISE-AD Phase 1b trial, evaluating multiple ascending doses of PMN310 in individuals with mild cognitive impairment due to Alzheimer’s disease or mild Alzheimer’s disease. The company plans to present blinded six-month interim safety and biomarker data in the coming weeks, followed by top-line unblinded results in early Q1 2027. ProMIS believes the new clinical evidence of direct amyloid-beta oligomer engagement further supports PMN310’s differentiated precision medicine approach and strengthens its potential as a disease-modifying therapy for Alzheimer’s disease.
Source: ProMIS Neurosciences,press release
