---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-26-208958"
form_type: "8-K"
ticker: "APVO"
cik: "0001671584"
company_name: "Aptevo Therapeutics Inc."
filed_at: "2026-05-06T23:59:59+00:00"
generated_at: "2026-05-14T22:47:33.644407+00:00"
event_type: "other_material"
sentiment: "positive"
materiality_score: 0.9
calibrated_materiality_score: 0.9
confidence: "high"
source: SEC EDGAR
---

# Aptevo Reports 87% Clinical Benefit Rate and 81% Remission in Frontline AML Trial RAINIER

## Summary
- Across 31 evaluable frontline AML patients, mipletamig combo showed 87% clinical benefit rate and 81% remission (CR/CRi), outperforming VIALE-A benchmark of 66.4%.
- Phase 1b dose optimization trial on track for 2026 completion; final cohorts 6 and 7 under enrollment with Cohort 6 nearing completion.
- 65% achieved complete remission vs 37% historical benchmark; 52% of remissions were MRD-negative.
- No cytokine release syndrome reported; 6 patients proceeded to allogeneic stem cell transplant.
- Phase 2 dose selection and regulatory interaction planned after dataset completion.

## SEC filing metadata
- accession: 0001193125-26-208958
- form_type: 8-K
- ticker: APVO
- cik: 0001671584
- company_name: Aptevo Therapeutics Inc.
- filed_at: 2026-05-06T23:59:59+00:00
- event_type: other_material
- sentiment: positive
- materiality_score: 0.9
- calibrated_materiality_score: 0.9
- confidence: high
- sec_items: 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1671584/000119312526208958/0001193125-26-208958-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1671584/000119312526208958/apvo-20260506.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-26-208958
- JSON: https://secwatch.observer/filing/0001193125-26-208958.json
- Plain text: https://secwatch.observer/filing/0001193125-26-208958.txt

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