---
schema_version: "secwatch.filing_event.v1"
accession: "0001671584-25-000005"
form_type: "8-K"
ticker: "APVO"
cik: "0001671584"
company_name: "Aptevo Therapeutics Inc."
filed_at: "2025-09-04T23:59:59+00:00"
generated_at: "2026-05-17T08:18:46.798300+00:00"
event_type: "other_material"
sentiment: "positive"
materiality_score: 0.6
calibrated_materiality_score: 0.6
confidence: "high"
source: SEC EDGAR
---

# Aptevo expands oncology pipeline with two new trispecific candidates APVO452 and APVO451

## Summary
- Filed provisional patents for APVO452 (PSMA x CD3 x CD40) targeting prostate cancer and APVO451 (Nectin-4 x CD3 x CD40) for multiple solid tumors.
- Trispecific design engages tumor antigen, T cells, and immunosuppressive cells via ADAPTIR-FLEX platform to modulate tumor microenvironment.
- Mipletamig clinical validation: >100 patients treated with high remission rates and no observed cytokine release syndrome in frontline AML.
- Pipeline now includes 8 bispecific/trispecific candidates; 5 employ CRIS-7-derived CD3 binding domain for improved safety.

## SEC filing metadata
- accession: 0001671584-25-000005
- form_type: 8-K
- ticker: APVO
- cik: 0001671584
- company_name: Aptevo Therapeutics Inc.
- filed_at: 2025-09-04T23:59:59+00:00
- event_type: other_material
- sentiment: positive
- materiality_score: 0.6
- calibrated_materiality_score: 0.6
- confidence: high
- sec_items: 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1671584/000167158425000005/0001671584-25-000005-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1671584/000167158425000005/apvo-20250904.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001671584-25-000005
- JSON: https://secwatch.observer/filing/0001671584-25-000005.json
- Plain text: https://secwatch.observer/filing/0001671584-25-000005.txt

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