---
schema_version: "secwatch.filing_event.v1"
accession: "0001213900-23-013059"
form_type: "8-K"
ticker: "ATNM"
cik: "0001388320"
company_name: "Actinium Pharmaceuticals, Inc."
filed_at: "2023-02-21T23:59:59+00:00"
generated_at: "2026-06-19T06:43:26.021052+00:00"
event_type: "other_material"
sentiment: "positive"
materiality_score: 0.9
calibrated_materiality_score: 0.9
confidence: "high"
source: SEC EDGAR
---

# Actinium announces positive Phase 3 SIERRA trial results for Iomab-B in r/r AML

## Summary
- Iomab-B met primary endpoint: 22% durable CR vs 0% control (p<0.0001).
- Event-free survival HR=0.22 (78% risk reduction, p<0.0001).
- Iomab-B doubled 1-year OS (26.1% vs 13.1%) and median OS (6.4 vs 3.2 months).
- Sepsis rate 4x lower (6.1% vs 28.6%); 100% engraftment in Iomab-B arm.
- Patients achieving dCR had 92% 1-year and 60% 2-year survival.

## SEC filing metadata
- accession: 0001213900-23-013059
- form_type: 8-K
- ticker: ATNM
- cik: 0001388320
- company_name: Actinium Pharmaceuticals, Inc.
- filed_at: 2023-02-21T23:59:59+00:00
- event_type: other_material
- sentiment: positive
- materiality_score: 0.9
- calibrated_materiality_score: 0.9
- confidence: high
- sec_items: 7.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1388320/000121390023013059/0001213900-23-013059-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1388320/000121390023013059/ea173990-8k_actinium.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001213900-23-013059
- JSON: https://secwatch.observer/filing/0001213900-23-013059.json
- Plain text: https://secwatch.observer/filing/0001213900-23-013059.txt

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