Related Experiment Video
Updated: Dec 21, 2025
Intracellular Phosphoflow Cytometry of Acute Myeloid Leukemia Patient-Derived Xenotransplants
Published on: June 6, 2025
Anti-FLT3 nanoparticles for acute myeloid leukemia: Preclinical pharmacology and pharmacokinetics
Mincheol Park1, Vijaya Pooja Vaikari2, Albert T Lam1
1Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA 90089, United States.
Abstract:
FLT3 receptor is an important therapeutic target in acute myeloid leukemia due to high incidence of mutations associated with poor clinical outcome. Targeted therapies against the FLT3 receptor, including small-molecule FLT3 tyrosine kinase inhibitors (TKIs) and anti-FLT3 antibodies, have demonstrated promising preclinical and even clinical efficacy. Yet, even with the current FDA approval for two FLT3 inhibitors, these modalities were unable to cure AML or significantly extend the lives of patients with a common mutation called FLT3-ITD. While FLT3 is a viable target, the approaches to inhibit its activity were inadequate. To develop a new modality for targeting FLT3, our team engineered an α-FLT3-A192 fusion protein composed of a single chain variable fragment antibody conjugated with an elastin-like polypeptide. These fusion proteins assemble into multi-valent nanoparticles with excellent stability and pharmacokinetic properties as well as in vitro and in vivo pharmacological activity in cellular and xenograft murine models of AML. In conclusion, α-FLT3-A192 fusions appear to be a viable new modality for targeting FLT3 in AML and warrant further preclinical development to bring it into the clinic.
Insights
New fusion proteins target FLT3 in acute myeloid leukemia (AML). These nanoparticles show promise for treating FLT3-mutated AML where current therapies fall short, offering a potential new treatment avenue.
Area of Science:
- Oncology
- Immunotherapy
- Biotechnology
Background:
- The FLT3 receptor is a key target in acute myeloid leukemia (AML), with mutations often linked to poor prognosis.
- Current FLT3 inhibitors, including TKIs and antibodies, have limitations in curing AML or improving survival for patients with FLT3-ITD mutations.
Purpose of the Study:
- To engineer a novel therapeutic modality targeting the FLT3 receptor in AML.
- To evaluate the preclinical efficacy of a new fusion protein-based nanoparticle system.
Main Methods:
- Engineered an α-FLT3-A192 fusion protein combining a single chain variable fragment antibody with an elastin-like polypeptide.
- Assessed the fusion protein's assembly into multi-valent nanoparticles, stability, pharmacokinetics, and in vitro/in vivo activity.
Main Results:
- The engineered α-FLT3-A192 fusion proteins self-assembled into stable nanoparticles.
- These nanoparticles demonstrated favorable pharmacokinetic properties and significant pharmacological activity in AML cellular and xenograft murine models.
Conclusions:
- α-FLT3-A192 fusion proteins represent a promising new strategy for targeting FLT3 in AML.
- Further preclinical development is warranted to advance this novel modality towards clinical application.
