---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-26-100539"
form_type: "8-K"
ticker: "APVO"
cik: "0001671584"
company_name: "Aptevo Therapeutics Inc."
filed_at: "2026-03-11T23:59:59+00:00"
generated_at: "2026-05-15T14:51:12.988327+00:00"
event_type: "other_material"
sentiment: "positive"
materiality_score: 0.75
calibrated_materiality_score: 0.75
confidence: "high"
source: SEC EDGAR
---

# Aptevo reports 86% clinical benefit rate for mipletamig combo in frontline AML, zero CRS

## Summary
- Mipletamig + venetoclax + azacitidine showed 86% clinical benefit rate (CR/CRi/PR) in 28 evaluable frontline AML patients.
- 79% achieved CR or CRi; 61% achieved CR; 55% of CR/CRi patients reached MRD-negative status.
- No cytokine release syndrome (CRS) observed; 35% of responders had high-risk TP53 mutation.
- Four patients proceeded to allogeneic stem cell transplant, a rare outcome in older/unfit patients.
- Data from RAINIER Phase 1b/2 trial and completed dose expansion trial support safety and tolerability.

## SEC filing metadata
- accession: 0001193125-26-100539
- form_type: 8-K
- ticker: APVO
- cik: 0001671584
- company_name: Aptevo Therapeutics Inc.
- filed_at: 2026-03-11T23:59:59+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/1671584/000119312526100539/0001193125-26-100539-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1671584/000119312526100539/apvo-20260310.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-26-100539
- JSON: https://secwatch.observer/filing/0001193125-26-100539.json
- Plain text: https://secwatch.observer/filing/0001193125-26-100539.txt

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