# Aptevo Therapeutics

Source: https://onco.cc/companies/aptevo-therapeutics/  
OnCo record `aptevo-therapeutics` (Company). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Aptevo Therapeutics is a Seattle company that builds antibody-like proteins which point the immune system at cancer. Its lead medicine, mipletamig, links T cells to leukaemia cells and is being tested in newly diagnosed acute myeloid leukaemia.

## Summary

Aptevo Therapeutics Inc., of Seattle, describes itself in its August 2026 registration statement as a clinical-stage company developing immunotherapies for cancer on two platforms it wholly owns, ADAPTIR and ADAPTIR-FLEX, with two clinical and six preclinical candidates. Mipletamig is a CD123 x CD3 T cell engager with a CRIS-7 CD3-binding domain, evaluated in RAINIER, a phase 1b/2 programme started in August 2024 in frontline acute myeloid leukaemia with venetoclax and azacitidine in patients unfit for intensive chemotherapy. ALG.APV-527 targets the co-stimulatory receptor 4-1BB and the tumour antigen 5T4 and is being evaluated in several solid tumour types.

## Fields

- Kind: Company
- Last checked: 2026-11-04
- Also known as: Aptevo Therapeutics Inc.
- HQ: Seattle, WA
- Type: biotech
- Website: https://www.aptevotherapeutics.com/
- Ticker: APVO

## Notes

- Read on 4 November 2026 in the S-1 filed with the SEC on 21 August 2026, which incorporates the annual report by reference. No 5T4 target record exists in OnCo. Trial registry numbers are not given in the filing.

## Sources

- SEC: Aptevo Therapeutics Form S-1, August 2026: https://www.sec.gov/Archives/edgar/data/1671584/000119312526361103/apvo-20260821.htm
- Official website: https://www.aptevotherapeutics.com/

## Connected records

- fronts: [Immunotherapy](https://onco.cc/fronts/immunotherapy/)
- technologies: [Bispecific antibodies](https://onco.cc/technologies/bispecific-antibody/), [T-cell engagers (bispecific)](https://onco.cc/technologies/t-cell-engager/)
- targets: [CD123](https://onco.cc/targets/cd123/), [CD137 (4-1BB, TNFRSF9)](https://onco.cc/targets/cd137/), [CD3](https://onco.cc/targets/cd3/)
- drugs: [ALG.APV-527](https://onco.cc/drugs/alg-apv-527/), [Mipletamig](https://onco.cc/drugs/mipletamig/)

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