---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-23-015154"
form_type: "8-K"
ticker: "DNTH"
cik: "0001690585"
company_name: "Dianthus Therapeutics, Inc. /DE/"
filed_at: "2023-01-25T23:59:59+00:00"
generated_at: "2026-06-20T09:33:28.196622+00:00"
event_type: "other_material"
sentiment: "negative"
materiality_score: 0.85
calibrated_materiality_score: 0.85
confidence: "high"
source: SEC EDGAR
---

# Magenta pauses MGTA-117 Phase 1/2 trial after participant death possibly related to drug

## Summary
- Latest participant dosed at Cohort 3 level (0.08 mg/kg) experienced Grade 5 SAE: respiratory failure and cardiac arrest leading to death.
- Death deemed possibly related to MGTA-117; reported to FDA as Suspected Unexpected Serious Adverse Reaction (SUSAR).
- Magenta voluntarily paused dosing after consultation with the trial's safety Cohort Review Committee.
- Trial is in relapsed/refractory acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS).

## SEC filing metadata
- accession: 0001193125-23-015154
- form_type: 8-K
- ticker: DNTH
- cik: 0001690585
- company_name: Dianthus Therapeutics, Inc. /DE/
- filed_at: 2023-01-25T23:59:59+00:00
- event_type: other_material
- sentiment: negative
- materiality_score: 0.85
- calibrated_materiality_score: 0.85
- confidence: high
- sec_items: 7.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1690585/000119312523015154/0001193125-23-015154-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1690585/000119312523015154/d395574d8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-23-015154
- JSON: https://secwatch.observer/filing/0001193125-23-015154.json
- Plain text: https://secwatch.observer/filing/0001193125-23-015154.txt

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