---
schema_version: "secwatch.filing_event.v1"
accession: "0001213900-24-064993"
form_type: "8-K"
ticker: "ATNM"
cik: "0001388320"
company_name: "Actinium Pharmaceuticals, Inc."
filed_at: "2024-08-05T23:59:59+00:00"
generated_at: "2026-05-31T13:02:50.668275+00:00"
event_type: "regulatory"
sentiment: "negative"
materiality_score: 0.9
calibrated_materiality_score: 0.9
confidence: "high"
source: SEC EDGAR
---

# FDA requires additional Phase 3 trial for Iomab-B; SIERRA alone not adequate for BLA filing

## Summary
- SIERRA met primary endpoint (dCR) with p<0.0001, but FDA now demands overall survival benefit in randomized head-to-head trial.
- New trial required: Iomab-B plus Flu/TBI vs cyclophosphamide plus Flu/TBI; no crossover allowed (vs 60% crossover in SIERRA).
- FDA suggests patient population could include all adult AML; specifics to be discussed in requested meeting.
- Actinium will seek a strategic partner for Iomab-B in U.S. after FDA interactions; focus shifts to Actimab-A, Iomab-ACT, preclinical.
- Management disappointed but will work with FDA; SIERRA supportive evidence for future BLA filing.

## SEC filing metadata
- accession: 0001213900-24-064993
- form_type: 8-K
- ticker: ATNM
- cik: 0001388320
- company_name: Actinium Pharmaceuticals, Inc.
- filed_at: 2024-08-05T23:59:59+00:00
- event_type: regulatory
- sentiment: negative
- 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/1388320/000121390024064993/0001213900-24-064993-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1388320/000121390024064993/ea0210560-8k_actinium.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001213900-24-064993
- JSON: https://secwatch.observer/filing/0001213900-24-064993.json
- Plain text: https://secwatch.observer/filing/0001213900-24-064993.txt

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