ProMIS Neurosciences advances Alzheimer's trial to final dose escalation cohort.

• ProMIS Neurosciences receives DSMB approval for Phase 1b Alzheimer's trial. • PMN310 trial enrolls Cohort 2, starts Cohort 3. • No amyloid-related imaging abnormalities (ARIA) observed. • Trial expected to report 6-month interim data in Q2 2026 and final results in Q4 2026.

ProMIS Neurosciences, Inc. (Nasdaq: PMN) has received approval from the Data and Safety Monitoring Board (DSMB) to advance its Phase 1b clinical trial, PRECISE-AD, for the treatment of Alzheimer's disease (AD). The DSMB's unanimous recommendation follows the successful completion of Cohort 2 enrollment and the initiation of Cohort 3, with no cases of amyloid-related imaging abnormalities (ARIA) observed to date. The trial is expected to report 6-month interim data in the second quarter of 2026 and final 12-month top-line results in the fourth quarter of 2026.

The approval to proceed to the third and final dose escalation cohort marks a significant milestone in the company's clinical development program for PMN310, a humanized IgG1 antibody targeting toxic amyloid-beta oligomers (AβOs). The DSMB's decision was based on cumulative safety data from all patients in the current and prior cohorts, with no ARIA observed. This favorable safety profile underscores the potential of PMN310 to address a critical unmet need in AD by targeting toxic oligomers without the risk of ARIA associated with other amyloid-directed therapies.

Neil Warma, President and CEO of ProMIS Neurosciences, stated, "The DSMB’s recommendation to proceed with the planned escalation to the final dose cohort underscores the steady progress of our Phase 1b program and keeps us firmly on track toward our planned interim and top-line data readouts in 2026. Together with the recent FDA Fast Track designation for PMN310, this achievement highlights the momentum we are building as we advance through clinical development."

The trial, which enrolled 128 patients, is designed to evaluate the safety, tolerability, and pharmacokinetics (PK) of multiple ascending doses of intravenous PMN310 in patients with Mild Cognitive Impairment due to AD and mild AD. The study will provide a robust dataset across biomarkers, safety outcomes, and clinical measures, informing the next phase of development.

ProMIS Neurosciences will discuss its clinical progress at the upcoming H.C. Wainwright 27th Annual Global Investment Conference on September 10, 2025, in New York, New York. The webcast of the presentation will be available on the company's website at www.promisneurosciences.com.

References:
[1] GlobeNewswire, "ProMIS Neurosciences Receives DSMB Approval to Advance to Cohort 3 in Alzheimer's Trial," September 3, 2025.