---
schema_version: "secwatch.filing_event.v1"
accession: "0000950170-23-062022"
form_type: "8-K"
ticker: "XENE"
cik: "0001582313"
company_name: "Xenon Pharmaceuticals Inc."
filed_at: "2023-11-09T23:59:59+00:00"
generated_at: "2026-06-08T06:41:58.664097+00:00"
event_type: "other_material"
sentiment: "negative"
materiality_score: 0.85
calibrated_materiality_score: 0.85
confidence: "high"
source: SEC EDGAR
---

# Xenon partner Neurocrine's Phase 2 trial of NBI-921352 in focal seizures fails

## Summary
- Phase 2 study of NBI-921352 in adult focal onset seizures failed to show meaningful seizure reduction.
- Neurocrine will not pursue further development of NBI-921352 in focal onset seizures.
- Xenon to review data for potential implications on ongoing SCN8A-developmental epileptic encephalopathy study.
- Neurocrine continues pre-clinical development of dual selective Nav1.2/1.6 inhibitor under collaboration.

## SEC filing metadata
- accession: 0000950170-23-062022
- form_type: 8-K
- ticker: XENE
- cik: 0001582313
- company_name: Xenon Pharmaceuticals Inc.
- filed_at: 2023-11-09T23:59:59+00:00
- event_type: other_material
- sentiment: negative
- materiality_score: 0.85
- calibrated_materiality_score: 0.85
- confidence: high
- sec_items: 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1582313/000095017023062022/0000950170-23-062022-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1582313/000095017023062022/xene-20231109.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0000950170-23-062022
- JSON: https://secwatch.observer/filing/0000950170-23-062022.json
- Plain text: https://secwatch.observer/filing/0000950170-23-062022.txt

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