What is FLT3-ITD?
FLT3-ITD (Fms-Like Tyrosine Kinase 3 - Internal Tandem Duplication) is a mutation found in approximately 30% of acute myeloid leukemia (AML) patients. This mutation activates the FLT3 protein, which drives leukemia cell growth and proliferation.
FLT3-ITD is an adverse prognostic factor in AML, but it also opens treatment opportunities with FLT3 inhibitors—targeted drugs that block the mutant FLT3 protein. Identification of FLT3-ITD status is essential for optimal AML treatment and clinical trial matching.
FLT3-ITD Status Categories
FLT3-ITD Positive
Frequency: ~30% of AML
Internal tandem duplication detected. Adverse prognostic factor with higher relapse risk. FLT3 inhibitors (midostaurin, sorafenib, crenolanib) significantly improve outcomes. Many trials specifically enroll FLT3-ITD patients.
FLT3 Wild-Type (Negative)
Frequency: ~70% of AML
No FLT3-ITD mutation. Prognosis depends on other molecular markers (NPM1, DNMT3A, TP53). Standard chemotherapy or targeted approaches used based on other biomarkers.
FLT3-TKD Mutation (Rare)
Frequency: ~7% of AML
Tyrosine kinase domain mutation (different from ITD). Associated with intermediate prognosis. May benefit from FLT3 inhibitors, but less responsive than FLT3-ITD.
FLT3 Inhibitors
Several FLT3 inhibitors are approved or in development for FLT3-ITD positive AML:
FDA-Approved Options:
- Midostaurin (Rydapt): Approved for FLT3-ITD+ AML in combination with standard chemotherapy
- Sorafenib: Multi-targeted kinase inhibitor approved for FLT3-ITD+ AML
Clinical Trial Options:
- Crenolanib: Highly selective FLT3 inhibitor in trials
- Gilteritinib (Xospata): FLT3 inhibitor approved for relapsed/refractory AML
- Combination strategies with chemotherapy and other targeted agents
Impact on Treatment
FLT3-ITD status significantly affects treatment strategy:
- Standard treatment: FLT3 inhibitor added to induction chemotherapy improves survival
- Fit patients: FLT3 inhibitor + chemotherapy followed by consolidation chemotherapy
- Unfit patients: Hypomethylating agent or low-dose chemotherapy + FLT3 inhibitor
- Relapsed/refractory: FLT3 inhibitor monotherapy or combination approaches
FLT3 Testing
FLT3-ITD status is determined by molecular testing:
- PCR (Polymerase Chain Reaction): Standard method detecting ITD mutations
- Next-generation sequencing: Can detect FLT3 mutations along with other genetic changes
- Testing should be performed at AML diagnosis
- Results guide both initial therapy and clinical trial eligibility
Find Matching Trials →
Frequently Asked Questions
What does FLT3-ITD positive mean for my AML?
▼
FLT3-ITD positive means your leukemia cells have a mutation that activates the FLT3 protein, which drives leukemia growth. This indicates:
- Your AML is more aggressive (higher relapse risk)
- You benefit from FLT3 inhibitor therapy added to chemotherapy
- You're eligible for FLT3-targeted clinical trials
- Your prognosis improves significantly with FLT3 inhibitor treatment
The discovery of FLT3-ITD has transformed AML treatment by enabling targeted therapy.
How is FLT3-ITD testing performed?
▼
FLT3-ITD testing is performed on leukemia cells from blood or bone marrow:
- PCR (Polymerase Chain Reaction): Most common method. Amplifies FLT3 gene and detects duplications
- Next-generation sequencing: Comprehensive test that detects FLT3 and other mutations simultaneously
- Testing typically takes 1-2 weeks
- Results available at AML diagnosis to guide treatment
What are FLT3 inhibitors and how do they work?
▼
FLT3 inhibitors are drugs that block the mutant FLT3 protein:
- How they work: Block the signaling pathway that drives leukemia cell growth
- Mechanism: Inhibit tyrosine kinase activity of FLT3
- Effect: Leukemia cells stop dividing and die
FLT3 inhibitors are most effective when combined with chemotherapy during AML treatment.
What are the side effects of FLT3 inhibitors?
▼
Common side effects of FLT3 inhibitors include:
- Nausea and vomiting: Usually manageable with medication
- Diarrhea: Common, often improves over time
- Fatigue: Energy levels may be lower
- Rash: Skin reactions in some patients
- Blood count effects: May worsen blood counts (part of overall treatment)
Most side effects are manageable and temporary. Your doctor will monitor closely during treatment.
Do I need FLT3 inhibitor therapy if I'm FLT3-ITD negative?
▼
No. FLT3 inhibitors are most beneficial for FLT3-ITD positive patients. However:
- FLT3-negative patients receive standard AML treatment (chemotherapy, targeted agents based on other biomarkers)
- Some studies are exploring FLT3 inhibitors in FLT3-negative patients in combination trials
- Your treatment plan depends on your complete molecular profile, not just FLT3
Your oncologist will determine the best treatment approach based on all your biomarkers.
How does FLT3-ITD status affect clinical trial eligibility?
▼
FLT3-ITD status opens many clinical trial opportunities:
- Many trials specifically enroll FLT3-ITD+ patients
- Trials test new FLT3 inhibitors and combinations
- Studies of FLT3 inhibitor + novel chemotherapy approaches
- Research on overcoming FLT3 inhibitor resistance
FLT3-ITD positive status significantly expands available clinical trial options.