---
schema_version: "secwatch.filing_event.v1"
accession: "0001140361-24-002995"
form_type: "8-K"
ticker: "IONS"
cik: "0000874015"
company_name: "IONIS PHARMACEUTICALS INC"
filed_at: "2024-01-22T23:59:59+00:00"
generated_at: "2026-06-06T20:53:30.436138+00:00"
event_type: "other_material"
sentiment: "positive"
materiality_score: 0.75
calibrated_materiality_score: 0.75
confidence: "high"
source: SEC EDGAR
---

# Ionis announces positive Phase 3 results for donidalorsen in HAE; NDA submission planned

## Summary
- Donidalorsen met primary endpoint: significant reduction in HAE attack rate for Q4W (p<0.001) and Q8W (p=0.004) vs placebo.
- Favorable safety profile; no serious adverse events in donidalorsen-treated patients.
- Ionis preparing NDA submission to U.S. FDA; Otsuka preparing MAA to European Medicines Agency.
- Third positive Phase 3 readout in 12 months, underscoring LICA platform strength.
- Over 90% of OASIS-HAE patients completed and entered OASIS-Plus open-label extension study.

## SEC filing metadata
- accession: 0001140361-24-002995
- form_type: 8-K
- ticker: IONS
- cik: 0000874015
- company_name: IONIS PHARMACEUTICALS INC
- filed_at: 2024-01-22T23:59:59+00:00
- event_type: other_material
- sentiment: positive
- materiality_score: 0.75
- calibrated_materiality_score: 0.75
- confidence: high
- sec_items: 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/874015/000114036124002995/0001140361-24-002995-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/874015/000114036124002995/ef20019323_8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001140361-24-002995
- JSON: https://secwatch.observer/filing/0001140361-24-002995.json
- Plain text: https://secwatch.observer/filing/0001140361-24-002995.txt

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