ProMIS Neurosciences (PMN) Stifel 2026 Healthcare Conference 2026 summary

Clinical program and timing

• Phase Ib trial enrolled 144 patients with early Alzheimer’s; randomized, double-blind, placebo-controlled design includes 12 months of IV dosing across three ascending doses.

• Final patient visits were expected to wrap up over the following month, with topline data targeted for Q1 next year.

• Trial evaluates safety, biomarkers, clinical efficacy and oligomer mechanism measures; PET scans are taken at baseline and study end, though little plaque-related change is expected.

• A six-month blinded interim analysis showed zero ARIA-E cases, zero serious treatment-related adverse events, zero treatment-related discontinuations and one infusion reaction.

• Interim p-tau217 and MTBR levels decreased from baseline to six months, while untreated patients typically show increases; management said these findings support the proposed mechanism.

Platform and differentiation

• EpiSelect predicts misfolded protein conformations and designs antibodies against three-dimensional epitopes management says are present on toxic oligomers, not amyloid-beta monomers or plaque.

• Management said side-by-side preclinical testing showed PMN310 did not bind plaque, unlike the other tested antibodies, including ACU193, donanemab and lecanemab.

• Management described PMN310’s IgG1 backbone as enabling microglial recruitment and oligomer clearance; it contrasted this with ACU193’s IgG2 backbone and lack of the same clearance mechanism.

• An assay designed to measure low-concentration soluble oligomers had validating data presented in July; it is being used in the clinical study to assess pre- and post-treatment levels.

Readout goals and interpretation

• Management’s target profile is ARIA, especially ARIA-E, near background levels, alongside efficacy at least comparable to marketed drugs; the trial is sized to identify trends, not a 0.05 efficacy p-value.

• Management cited 15%-20% slowing of cognition versus placebo at 12 months, with supportive biomarker trends, as a potential win; efficacy above 20% separation would be upside.

• The study has 95%+ power to detect a single ARIA case; management said favorable safety and efficacy trends are the key aims in this 140-patient analysis.

• Management said lowering MRI monitoring from six scans per year to one or two could materially improve treatment practicality if safety findings support it.