---
schema_version: "secwatch.filing_event.v1"
accession: "0001564590-22-013022"
form_type: "8-K"
ticker: "ORKA"
cik: "0000907654"
company_name: "Oruka Therapeutics, Inc."
filed_at: "2022-03-31T23:59:59+00:00"
generated_at: "2026-06-26T12:58:10.107397+00:00"
event_type: "other_material"
sentiment: "negative"
materiality_score: 0.85
calibrated_materiality_score: 0.85
confidence: "high"
source: SEC EDGAR
---

# ARCA biopharma's rNAPc2 fails to meet primary endpoint in Phase 2b COVID-19 trial

## Summary
- Pooled rNAPc2 reduced D-dimer 16.8% vs heparin 11.2% (P=0.47), missing statistical significance.
- Per-protocol analysis: rNAPc2 reduced D-dimer 28.7% vs heparin increase 1.1% (P=0.33).
- In WHO Severe patients, heparin D-dimer increased 29.0% (P=0.022); rNAPc2 changed 25.9% (P=0.16).
- Thrombotic events: 9 in heparin group vs 6 in rNAPc2; hazard ratio for recovery 0.88, neither significant.
- Company will not pursue direct superiority trial vs heparin for COVID-19; evaluating partnering and strategic options.

## SEC filing metadata
- accession: 0001564590-22-013022
- form_type: 8-K
- ticker: ORKA
- cik: 0000907654
- company_name: Oruka Therapeutics, Inc.
- filed_at: 2022-03-31T23:59:59+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/907654/000156459022013022/0001564590-22-013022-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/907654/000156459022013022/abio-8k_20220331.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001564590-22-013022
- JSON: https://secwatch.observer/filing/0001564590-22-013022.json
- Plain text: https://secwatch.observer/filing/0001564590-22-013022.txt

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