---
schema_version: "secwatch.filing_event.v1"
accession: "0001104659-26-087269"
form_type: "8-K"
ticker: "PMN"
cik: "0001374339"
company_name: "ProMIS Neurosciences Inc."
filed_at: "2026-07-28T10:05:27+00:00"
generated_at: "2026-07-28T10:10:03.841172+00:00"
event_type: "other_material"
sentiment: "positive"
materiality_score: 0.75
calibrated_materiality_score: 0.75
confidence: "high"
source: SEC EDGAR
---

# ProMIS reports positive blinded 6-month interim data for PMN310 in Alzheimer's Phase 1b trial

## Summary
- No ARIA-E observed across all genotypes; 4.4% total ARIA (all mild, asymptomatic ARIA-H) with no drug-related discontinuations.
- 61% of patients were APOE4 carriers (11% homozygotes); no ARIA-E in any genotype, including this high-risk group.
- 68.5% of patients had decline in plasma pTau217; 62.5% had decline in CSF MTBR-tau243, consistent with target engagement.
- Trial remains blinded; unblinded 12-month topline efficacy data expected in Q1 2027.
- PMN310 designed to selectively bind toxic amyloid-beta oligomers while avoiding plaque, aiming to decouple efficacy from ARIA risk.

## SEC filing metadata
- accession: 0001104659-26-087269
- form_type: 8-K
- ticker: PMN
- cik: 0001374339
- company_name: ProMIS Neurosciences Inc.
- filed_at: 2026-07-28T10:05:27+00:00
- event_type: other_material
- sentiment: positive
- materiality_score: 0.75
- calibrated_materiality_score: 0.75
- confidence: high
- sec_items: 7.01, 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1374339/000110465926087269/0001104659-26-087269-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1374339/000110465926087269/pmn-20260728x8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001104659-26-087269
- JSON: https://secwatch.observer/filing/0001104659-26-087269.json
- Plain text: https://secwatch.observer/filing/0001104659-26-087269.txt

This AI-assisted summary is a reading aid. Review the linked SEC EDGAR filing before relying on any specific claim.