---
schema_version: "secwatch.filing_event.v1"
accession: "0000950170-25-042340"
form_type: "8-K"
ticker: "APVO"
cik: "0001671584"
company_name: "Aptevo Therapeutics Inc."
filed_at: "2025-03-20T23:59:59+00:00"
generated_at: "2026-05-24T10:20:44.549658+00:00"
event_type: "other_material"
sentiment: "positive"
materiality_score: 0.85
calibrated_materiality_score: 0.85
confidence: "high"
source: SEC EDGAR
---

# Two additional AML patients achieve remission in Cohort 2 of RAINIER trial; 90% response rate

## Summary
- Two additional AML patients in Cohort 2 of RAINIER trial achieved remission within 30 days of treatment.
- Overall 9 of 10 frontline AML patients achieved remission with mipletamig + ven/aza triplet, vs 66% doublet benchmark.
- Complete remission rate (CR) of 70% with triplet outperforms 36% CR from Viale-A ven/aza only study.
- No cytokine release syndrome (CRS) observed in RAINIER trial to date; all remissions ongoing.
- Cohort 2 enrollment nearing completion; six patients planned at 18 mcg dose level.

## SEC filing metadata
- accession: 0000950170-25-042340
- form_type: 8-K
- ticker: APVO
- cik: 0001671584
- company_name: Aptevo Therapeutics Inc.
- filed_at: 2025-03-20T23:59:59+00:00
- event_type: other_material
- sentiment: positive
- materiality_score: 0.85
- calibrated_materiality_score: 0.85
- confidence: high
- sec_items: 7.01, 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1671584/000095017025042340/0000950170-25-042340-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1671584/000095017025042340/apvo-20250320.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0000950170-25-042340
- JSON: https://secwatch.observer/filing/0000950170-25-042340.json
- Plain text: https://secwatch.observer/filing/0000950170-25-042340.txt

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