---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-25-312972"
form_type: "8-K"
ticker: "APVO"
cik: "0001671584"
company_name: "Aptevo Therapeutics Inc."
filed_at: "2025-12-09T23:59:59+00:00"
generated_at: "2026-05-16T13:48:10.462767+00:00"
event_type: "other_material"
sentiment: "positive"
materiality_score: 0.75
calibrated_materiality_score: 0.75
confidence: "high"
source: SEC EDGAR
---

# Aptevo reports mipletamig 93% ORR, zero CRS in frontline AML Phase 1b/2 trial at ASH 2025

## Summary
- 100% of patients free of cytokine release syndrome (CRS) across cohorts 1-3.
- 93% overall response rate (ORR) among evaluable patients; 87% CR/CRi, 73% CR.
- 60% of MRD-evaluable CR/CRi patients achieved MRD-negative status; 43% of ORR patients had TP53 mutation.
- Median patient age 75; triplet regimen (mipletamig + AZA/VEN) generally well tolerated.
- Data presented Dec 8 at ASH 2025; RAINIER trial continues enrollment at additional dose levels.

## SEC filing metadata
- accession: 0001193125-25-312972
- form_type: 8-K
- ticker: APVO
- cik: 0001671584
- company_name: Aptevo Therapeutics Inc.
- filed_at: 2025-12-09T23:59:59+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/1671584/000119312525312972/0001193125-25-312972-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1671584/000119312525312972/apvo-20251209.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-25-312972
- JSON: https://secwatch.observer/filing/0001193125-25-312972.json
- Plain text: https://secwatch.observer/filing/0001193125-25-312972.txt

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