---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-25-189109"
form_type: "8-K"
ticker: "AMLX"
cik: "0001658551"
company_name: "Amylyx Pharmaceuticals, Inc."
filed_at: "2025-08-27T23:59:59+00:00"
generated_at: "2026-05-17T09:43:22.788212+00:00"
event_type: "other_material"
sentiment: "negative"
materiality_score: 0.6
calibrated_materiality_score: 0.6
confidence: "high"
source: SEC EDGAR
---

# Amylyx discontinues AMX0035 program for PSP after Phase 2b miss

## Summary
- AMX0035 failed to show differences vs placebo on primary or secondary outcomes at Week 24.
- Company will discontinue Phase 2b trial and open-label extension; will not proceed to Phase 3.
- Safety data consistent with prior AMX0035 studies.
- ORION program for progressive supranuclear palsy (PSP) is discontinued entirely.

## SEC filing metadata
- accession: 0001193125-25-189109
- form_type: 8-K
- ticker: AMLX
- cik: 0001658551
- company_name: Amylyx Pharmaceuticals, Inc.
- filed_at: 2025-08-27T23:59:59+00:00
- event_type: other_material
- sentiment: negative
- materiality_score: 0.6
- calibrated_materiality_score: 0.6
- confidence: high
- sec_items: 8.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1658551/000119312525189109/0001193125-25-189109-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1658551/000119312525189109/d23231d8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-25-189109
- JSON: https://secwatch.observer/filing/0001193125-25-189109.json
- Plain text: https://secwatch.observer/filing/0001193125-25-189109.txt

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