PMN310 - (PRECISE-AD)

July 28, 2026: ProMIS Neurosciences Inc. (NASDAQ: PMN) reported positive blinded six-month interim safety and biomarker observations from PRECISE-AD (NCT06750432), its Phase 1b randomized, double-blind, placebo-controlled trial of PMN310 in patients with mild cognitive impairment due to Alzheimer’s disease or mild Alzheimer’s disease. In a blinded interim analysis of 136 patients, PMN310 showed a favorable safety profile with no cases of ARIA-E reported as of the data cutoff; total ARIA was 4.4%, all mild and asymptomatic and consisting only of ARIA-H. The company reported no treatment-related serious adverse events and no drug-related discontinuations, including in a population with 61% APOE4 carriers (11% homozygotes).

Blinded pooled biomarker trends showed declines from baseline in a majority of patients: 68.5% had non-increasing plasma pTau217 and 62.5% had non-increasing CSF MTBR-tau243, though the company emphasized these blinded findings are not determinative of efficacy.

The trial has completed enrollment of 144 participants across 5, 10, and 20 mg/kg IV cohorts treated for 12 months; unblinded 12-month topline data (including efficacy) are expected in Q1 2027.