| Approved indication (as of 2024) |
Japan: FLT3‑ITD‑positive AML, including relapsed/refractory disease.
United States & EU: Not yet FDA‑ or EMA‑approved; available only through clinical trials or special‑access programs. |
| Mechanism of action |
Competitive inhibition of the ATP‑binding site of FLT3, shutting down downstream signaling that promotes leukemic cell survival and proliferation. |
| Dosage (Japanese regimen) |
25 mg once daily, taken continuously for 21 days, followed by a 7‑day rest (i.e., 28‑day cycle). Dose adjustments may be made for toxicity. |
| Common side effects |
• Myelosuppression (neutropenia, anemia, thrombocytopenia)
• Gastro‑intestinal: nausea, vomiting, diarrhea, mucositis
• Fatigue, headache, rash
• Cardiac: QT‑interval prolongation (rarely torsades de pointes) |
| Serious risks |
• QT‑interval prolongation → risk of life‑threatening arrhythmias
• Severe myelosuppression → infections, bleeding
• Liver enzyme elevations (monitor LFTs) |
| Monitoring |
• Baseline & periodic ECGs (QTc measurement)
• CBC, LFTs, electrolytes (K⁺, Mg²⁺) each cycle
• Watch for signs of infection or bleeding |
| Drug interactions |
• Concomitant use with other QT‑prolonging agents (e.g., macrolide antibiotics, some anti‑arrhythmics) should be avoided or closely monitored.
• CYP3A4 inhibitors/inducers can alter quizartinib exposure; adjust dose accordingly (e.g., ketoconazole increases, rifampicin decreases). |
| Contraindications |
• Known hypersensitivity to quizartinib or any excipient.
• Severe hepatic impairment (ALT/AST > 5× ULN).
• Baseline QTc > 470 ms (in some protocols). |
| Patient counseling points |
• Take with food or as directed to improve absorption.
• Maintain regular follow‑up appointments for ECG and blood counts.
• Report any palpitations, dizziness, fainting, or chest discomfort promptly.
• Avoid OTC or prescription medications that can prolong QT unless cleared by the treating team.
• Notify your doctor of any new symptoms—especially fever, sore throat, or bleeding. |