ProMIS Reports Positive Phase Ia Trial Results for Alzheimer's Treatment

ProMIS Neurosciences has revealed positive top-line findings from the Phase Ia clinical trial of PMN310, a humanised monoclonal antibody, aimed at treating Alzheimer’s disease. The trial, which was randomised, double-blind, and placebo-controlled, evaluated the safety and tolerability of intravenously administered PMN310 in healthy subjects across two active sites in the US, involving a total of 40 subjects.

The study focused on single-ascending dose (SAD) cohorts, with results from the first four cohorts already reported. The fifth and final cohort is currently under final assessment. Findings indicate that PMN310 is well-tolerated and possesses a favourable safety profile. Notably, PMN310 successfully crossed the blood-brain barrier in a dose-dependent manner, achieving concentrations that suggest sufficient target engagement for the planned follow-on trial in Alzheimer’s patients.

This trial was initiated based on nonclinical studies that underscored PMN310’s selective targeting of AβOs, which are considered a potential cause of Alzheimer’s. The trial observed no treatment-emergent serious adverse events. Furthermore, PMN310 levels in the cerebrospinal fluid demonstrated dose proportionality and exceeded expected oligomer levels by over a hundredfold. The half-life of PMN310 in the CSF was approximately 25 days, hinting at the feasibility of monthly dosing.

Larry Altstiel, ProMIS Neurosciences' chief medical officer, commented on the findings: “These encouraging data from the first four cohorts of our first-in-human Phase Ia clinical trial of PMN310 in healthy volunteers support the safety and tolerability profile of PMN310, and the levels of PMN310 in the CSF suggest its potential for target engagement. Importantly, these results will inform the dosing of our Phase Ib clinical trial in Alzheimer’s patients, which is on track to initiate in the second half of 2024.”