Quizar 26.5mg, Quizartinib Tablets

Quizar 26.5mg is a branded formulation of Quizartinib, a potent, oral tyrosine kinase inhibitor (TKI). It is primarily indicated for the treatment of adult patients with acute myeloid leukemia (AML), especially those with FLT3-ITD mutation, a common and aggressive genetic alteration found in AML cases. Quizar provides a targeted approach in managing cancer progression by inhibiting specific molecular pathways crucial for leukemia cell survival and proliferation.

What is Quizar (Quizartinib)?

Quizar contains Quizartinib, a small-molecule drug developed to selectively target FLT3 (FMS-like tyrosine kinase 3), especially the internal tandem duplication (ITD) mutation subtype. FLT3 mutations are found in approximately 30% of AML patients and are associated with a poor prognosis. Quizar is a second-generation FLT3 inhibitor that helps manage AML in patients who have relapsed or are refractory to prior therapies.

How it Works / Mechanism of Action

Quizartinib works by selectively inhibiting the FLT3 receptor tyrosine kinase, particularly the FLT3-ITD mutation, which plays a key role in the uncontrolled growth of leukemic cells.

• Normal FLT3 function: It helps in the development of early blood cells in the bone marrow.
• In mutated FLT3: Constant activation leads to excessive proliferation of immature white blood cells, causing AML.
• Quizartinib binds to the ATP-binding site of FLT3, preventing its activation and subsequent signaling. This stops AML cells with FLT3 mutations from growing and causes apoptosis, or programmed cell death.

How to Use / Indications

Quizar is used under strict oncological guidance and is specifically indicated for:

• Adults with a FLT3-ITD mutation who have relapsed or refractory AML
• frequently used either alone or in conjunction with hematopoietic stem cell transplantation or chemotherapy.
• Treatment decisions are based on genetic testing confirming the presence of FLT3-ITD mutation.

How to Take / Dosage

Standard Recommended Dosage of Quizar (Quizartinib):

• Starting dose: 26.5mg orally once daily for the first 14 days (to reduce initial QT prolongation risk)
• Maintenance dose: Increased to 26.5 mg once daily on day 15 and continued thereafter
• Cycle of treatment: Continued until the condition worsens or the toxicity becomes intolerable

Administration instructions:

• Take with or without food at the same time every day.
• Do not chew, break, or crush the tablet; instead, swallow it whole.
• If you miss a dose, take it as soon as you recall, unless it’s almost time for the next one.

Other Dosage Forms / Considerations

Tablet strength: 26.5 mg (initial titration dose), 26.5 mg (maintenance dose)

Dosage adjustments may be required in:

• QTc prolongation
• Liver impairment
• Drug-drug interactions
• Hematological toxicities (e.g., neutropenia, thrombocytopenia)
• Always consult with a hematologist-oncologist before adjusting the dose.

Side Effects

Common and serious side effects associated with Quizar (Quizartinib) include:

Common:

• Nausea, vomiting
• Fatigue
• Constipation or diarrhea
• Headache
• Low potassium or magnesium levels
• Rash

Serious:

• QT interval prolongation (can cause life-threatening arrhythmias)
• Febrile neutropenia
• Anemia
• Low white blood cell count infections
• Tumor lysis syndrome (rare but critical)
• Patients must be monitored regularly with ECGs, electrolytes, and complete blood counts.

Storage

• Store Quizar tablets at room temperature (20–25°C).
• Keep in the original container with the lid tightly closed to protect from moisture.
• Keep out of reach of children and do not refrigerate.
• Do not use expired medicine; dispose of it safely as per pharmacy guidelines.

Benefits

• Targeted therapy: Acts specifically on FLT3-ITD mutations, improving efficacy while minimizing impact on normal cells.
• Improved survival: Shown to prolong overall survival and reduce relapse in AML patients.
• Oral formulation: Offers convenience for long-term use compared to IV treatments.
• Option for resistant AML: Effective in patients not responding to first-line therapies or relapsed after transplant.

Prescription

Quizar is a prescription-only medicine and should be:

• Prescribed by a hematologist or oncologist
• Used only after confirmation of FLT3-ITD mutation via diagnostic genetic testing
• Monitored under supervision with frequent ECGs and labs
• It is included in several global treatment protocols and may be covered under certain compassionate use or special access programs in some regions.

Drug Interactions

Quizartinib can interact with other drugs and is mostly metabolized by CYP3A4 enzymes.

Avoid concurrent use with:

• Strong CYP3A4 inhibitors (e.g., ketoconazole, clarithromycin)
• Strong CYP3A4 inducers (e.g., rifampin, carbamazepine)
• QT-prolonging agents (e.g., haloperidol, methadone, amiodarone)
• Without expert assistance, antifungals, antibiotics, or HIV protease inhibitors

Food interactions:

• Steer clear of grapefruits and grapefruit juice as they can raise blood
• Always inform your doctor of any medications or supplements you are taking.

FAQs

Can I stop Quizar if I feel better?

No, always continue as prescribed unless advised by your doctor.

How soon will I see results?

Results vary; some patients respond within weeks, others may take longer.

Can pregnant women take Quizar ?

No, it is contraindicated in pregnancy due to risk of fetal harm.

Is it safe with heart problems?

Caution is required; regular ECG monitoring is essential.

Conclusion

Quizar 26.5mg (Quizartinib) represents a significant advancement in the treatment of FLT3-ITD mutated acute myeloid leukemia, offering hope for patients with limited options. Its selective mechanism of action, oral administration, and potential survival benefits make it a key part of targeted AML therapy. However, its use requires strict medical supervision due to potential cardiac risks and interactions. With proper monitoring and adherence, Quizar can greatly contribute to improved outcomes in relapsed or refractory AML cases.