Xospata: Uses, Dosage & Side Effects
A selective FLT3 inhibitor for the treatment of relapsed or refractory FLT3-mutated acute myeloid leukemia (AML) in adults
Xospata (gilteritinib) is a targeted anticancer medication belonging to the class of protein kinase inhibitors. It is used to treat adult patients with acute myeloid leukemia (AML), a type of cancer affecting certain white blood cells, when the disease carries a mutation in the FLT3 gene. Xospata is prescribed for patients whose AML has relapsed (returned) after prior treatment or has not responded to previous therapy (refractory disease). By selectively blocking the mutated FLT3 enzymes that drive leukemic cell growth, gilteritinib helps to stop the cancer from spreading. Xospata is taken as an oral tablet once daily and requires a prescription.
Quick Facts: Xospata
Key Takeaways
- Xospata (gilteritinib) is a selective FLT3 inhibitor approved for adults with relapsed or refractory acute myeloid leukemia (AML) carrying FLT3 mutations, including both ITD and TKD mutation types.
- The recommended dose is 120 mg (three 40 mg tablets) taken orally once daily, with or without food; tablets must be swallowed whole and should not be crushed or split.
- Differentiation syndrome is a potentially serious side effect that can occur within the first 3 months of treatment; symptoms include fever, breathing difficulties, rapid weight gain, and swelling requiring immediate medical attention.
- Xospata may cause QT prolongation and other cardiac effects; regular monitoring of heart function, electrolytes, and blood counts is required throughout treatment.
- Women must use effective contraception during treatment and for 6 months after the last dose; men must use contraception for 4 months after treatment ends; breastfeeding must be avoided during treatment and for 2 months after the last dose.
What Is Xospata and What Is It Used For?
Xospata contains the active substance gilteritinib, which belongs to a group of anticancer medicines called protein kinase inhibitors. These medications work by blocking specific enzymes (kinases) that play critical roles in the growth and survival of cancer cells. Gilteritinib was developed as a targeted therapy specifically for patients with acute myeloid leukemia (AML) whose cancer cells harbor mutations in the FMS-like tyrosine kinase 3 (FLT3) gene.
Acute myeloid leukemia is a type of cancer that originates in the bone marrow, the spongy tissue inside bones where blood cells are produced. In AML, the bone marrow produces large numbers of abnormal white blood cells (myeloid blasts) that crowd out normal blood cells, leading to anemia, increased susceptibility to infections, and bleeding problems. AML is one of the most common types of acute leukemia in adults, with approximately 20,000 new cases diagnosed in the United States and 18,000 in Europe each year. Despite intensive treatment with chemotherapy and sometimes stem cell transplantation, many patients experience relapse or have disease that does not respond to initial treatment.
FLT3 mutations are among the most common genetic alterations found in AML, occurring in approximately 25–30% of all patients with this disease. The FLT3 gene encodes a receptor tyrosine kinase that normally plays a role in the development and survival of blood cells. When the FLT3 gene is mutated, the resulting receptor is constitutively activated — meaning it is permanently “switched on” — which drives uncontrolled proliferation of leukemic cells. There are two main types of FLT3 mutations: internal tandem duplication (ITD) mutations, which are the most common and are associated with a particularly poor prognosis, and tyrosine kinase domain (TKD) mutations, which are less frequent but also contribute to leukemia progression.
Gilteritinib works by selectively inhibiting the FLT3 receptor, including both ITD and TKD mutant forms. By blocking these mutated kinases, gilteritinib prevents the signaling pathways that leukemic cells depend on for their growth and survival. This leads to cell cycle arrest and apoptosis (programmed cell death) of the abnormal white blood cells. The selectivity of gilteritinib for FLT3 is an important feature, as it means the drug can target the cancer cells while causing relatively less damage to normal cells compared with conventional chemotherapy.
Xospata is approved by the European Medicines Agency (EMA), the U.S. Food and Drug Administration (FDA), and regulatory authorities in Japan and many other countries for the treatment of adult patients with relapsed or refractory FLT3-mutated AML. The approval was based on the results of the pivotal ADMIRAL trial (Study 2215-CL-0301), a randomized, open-label, multicenter phase 3 clinical trial that compared gilteritinib monotherapy with salvage chemotherapy in patients with FLT3-mutated relapsed or refractory AML. The ADMIRAL trial demonstrated that gilteritinib significantly improved overall survival compared with chemotherapy, with a median overall survival of 9.3 months versus 5.6 months. Additionally, gilteritinib achieved a higher rate of complete remission with full or partial hematologic recovery.
Before starting Xospata, your doctor will test your leukemia cells for FLT3 mutations using a validated diagnostic test. This test determines whether your AML carries a FLT3 mutation that makes it suitable for treatment with gilteritinib. The FLT3 mutation status is a critical piece of information that guides treatment decisions in AML, as targeted therapies like Xospata are only effective in patients whose cancer cells depend on the mutated FLT3 pathway for growth.
What Should You Know Before Taking Xospata?
Contraindications
Xospata must not be taken if you are allergic (hypersensitive) to gilteritinib or any of the other ingredients contained in the tablets (mannitol, hydroxypropylcellulose, low-substituted hydroxypropylcellulose, magnesium stearate, hypromellose, talc, macrogol, titanium dioxide, or yellow iron oxide). Allergic reactions may include rash, itching, swelling, or difficulty breathing. If you have experienced an allergic reaction to any component of the formulation, inform your doctor immediately, as Xospata should not be used in this situation.
Warnings and Precautions
Differentiation syndrome is a potentially life-threatening condition that can occur at any time during the first 3 months of Xospata treatment, sometimes as early as the first day. Symptoms include fever, breathing difficulties, rash, dizziness or feeling faint, rapid weight gain, and swelling of the arms or legs. If you experience any of these symptoms, contact your doctor immediately. Your doctor may prescribe corticosteroids and temporarily interrupt Xospata therapy until symptoms resolve. It is important to carry your patient alert card and show it to any healthcare professional you see.
PRES is a rare but serious condition affecting the brain that has been reported in patients treated with Xospata. Symptoms include seizures, rapidly worsening headache, reduced alertness, confusion, blurred vision, or other visual disturbances. If you notice any of these symptoms, seek medical attention immediately. Your doctor may perform imaging tests to determine if PRES has developed, and Xospata treatment will be stopped if PRES is confirmed.
Before starting and during treatment with Xospata, talk to your doctor, pharmacist, or nurse about the following conditions:
- Heart rhythm disorders: If you have or have had any irregular heartbeat or a condition known as QT prolongation, inform your doctor. Xospata can cause QT prolongation, which may lead to serious heart rhythm disturbances. Your doctor will monitor your heart function with electrocardiograms (ECGs) before and during treatment.
- Low electrolyte levels: If you have a history of low potassium (hypokalemia) or low magnesium (hypomagnesemia), the risk of abnormal heart rhythms is increased. Your doctor will check your electrolyte levels before starting Xospata and correct any imbalances before treatment begins.
- Pancreatitis: Severe pain in the upper abdomen and back, with nausea and vomiting, may indicate inflammation of the pancreas (pancreatitis). Report these symptoms to your doctor promptly.
Your doctor will perform regular blood tests before and during treatment with Xospata to monitor your blood cell counts, liver function, electrolytes, and other important parameters. Regular cardiac monitoring, including electrocardiograms, will also be conducted to check for QT prolongation and other cardiac effects.
Children and Adolescents
Xospata should not be given to children and adolescents under 18 years of age. The safety and effectiveness of gilteritinib have not been established in this age group, and there are currently insufficient data to support its use in pediatric patients.
Pregnancy and Breastfeeding
Xospata may harm an unborn baby and must not be used during pregnancy. Women who are taking Xospata and who could become pregnant must use effective contraception during treatment and for at least 6 months after the last dose. If you use hormonal contraception, you must also use a barrier method such as a condom or diaphragm. Men taking Xospata whose partner could become pregnant must use effective contraception during treatment and for at least 4 months after the last dose.
It is not known whether gilteritinib passes into breast milk. Because of the potential for serious adverse effects in nursing infants, breastfeeding must be avoided during treatment with Xospata and for at least 2 months after the last dose. If you are pregnant, think you may be pregnant, or are planning to have a baby, consult your doctor, pharmacist, or nurse before taking this medicine.
Xospata may cause dizziness. If you experience dizziness after taking this medication, do not drive or operate machinery until the symptoms resolve. This is important for your safety and the safety of others.
How Does Xospata Interact with Other Drugs?
Gilteritinib is primarily metabolized by the CYP3A4 enzyme system in the liver, which means that other drugs affecting this enzyme can significantly alter the levels of Xospata in your body. Additionally, gilteritinib itself can act as an inhibitor of certain drug transporters and enzymes, potentially affecting the levels of other medications. Because of these complex interactions, it is essential to inform your doctor, pharmacist, or nurse about all medications you are currently taking, have recently taken, or may take in the future, including over-the-counter drugs, herbal remedies, and dietary supplements.
Major Interactions
The following drug interactions are considered clinically significant and may require dose adjustments, alternative medications, or enhanced monitoring:
| Interacting Drug | Drug Category | Effect | Clinical Recommendation |
|---|---|---|---|
| Rifampicin | Anti-tuberculosis | Strong CYP3A4 inducer; significantly reduces gilteritinib levels | Avoid concurrent use; consider alternative anti-TB therapy |
| Phenytoin | Antiepileptic | Strong CYP3A4 inducer; reduces gilteritinib efficacy | Your doctor may switch to an alternative antiepileptic |
| Voriconazole / Posaconazole / Itraconazole | Antifungal | Strong CYP3A4 inhibitors; increase gilteritinib levels and toxicity risk | Monitor closely; dose reduction of Xospata may be necessary |
| Ritonavir | HIV antiretroviral | Strong CYP3A4 inhibitor; increases gilteritinib exposure | Monitor for increased side effects; dose adjustment may be needed |
| St. John’s Wort | Herbal supplement | CYP3A4 inducer; may reduce gilteritinib effectiveness | Avoid concurrent use during Xospata treatment |
Other Important Interactions
In addition to the major interactions listed above, Xospata may interact with a range of other medications. Because gilteritinib can inhibit certain drug transporters (such as P-glycoprotein, BCRP, and organic cation transporters), it may increase the blood levels of drugs that are substrates of these transporters. This is particularly important for medications with a narrow therapeutic index, where even small changes in blood levels can lead to significant side effects.
| Interacting Drug | Drug Category | Effect |
|---|---|---|
| Erythromycin / Clarithromycin / Azithromycin | Antibiotics (macrolides) | Moderate CYP3A4 inhibitors; may increase gilteritinib levels |
| Mitoxantrone / Methotrexate | Anticancer agents | Xospata may affect their transport and clearance |
| Digoxin | Cardiac glycoside | Gilteritinib inhibits P-gp; may increase digoxin levels |
| Dabigatran | Anticoagulant | Gilteritinib inhibits P-gp; may increase dabigatran levels and bleeding risk |
| Rosuvastatin | Statin (cholesterol lowering) | Gilteritinib inhibits BCRP; may increase rosuvastatin exposure |
| Metformin | Antidiabetic | Gilteritinib inhibits OCT; may affect metformin clearance |
| Escitalopram / Fluoxetine / Sertraline | Antidepressants (SSRIs) | Potential for interaction; monitor for changes in efficacy or side effects |
| Captopril / Carvedilol | Antihypertensives | Potential transporter-mediated interaction; monitor blood pressure |
If you are currently taking any of the medications listed above, your doctor may decide to switch you to an alternative medication during your treatment with Xospata, or may adjust the dose and increase monitoring for potential adverse effects. Never stop or change any medication without consulting your doctor first.
What Is the Correct Dosage of Xospata?
Always take Xospata exactly as your doctor or pharmacist has told you. If you are unsure about any aspect of your treatment, ask your doctor or pharmacist for clarification. The dosage and duration of treatment are individualized based on your medical condition, response to therapy, and tolerance of side effects.
Adults
Standard Adult Dose
The recommended starting dose is 120 mg (three 40 mg tablets) once daily. Take your dose at the same time each day. Swallow the tablets whole with water — do not split, crush, or chew them. Xospata can be taken with or without food.
Your doctor may decide to increase or decrease your dose, or temporarily interrupt treatment, depending on how you respond to the medication and whether you experience side effects. Dose adjustments are commonly made in response to differentiation syndrome, QT prolongation, or significant changes in blood counts or liver function tests. It is important to continue treatment for as long as your doctor advises, as the therapeutic effect of Xospata may take time to develop fully.
| Patient Group | Dose | Frequency | Notes |
|---|---|---|---|
| Adults (18+ years) | 120 mg (3 × 40 mg) | Once daily | Standard recommended dose |
| Dose reduction (if needed) | 80 mg (2 × 40 mg) | Once daily | For management of adverse reactions |
| Children (<18 years) | Not recommended | N/A | Safety and efficacy not established |
Missed Dose
If you forget to take Xospata at your usual time, take your normal dose as soon as you remember on the same day. Then take your next dose at the usual time the following day. Do not take a double dose to make up for a missed dose. If you are unsure about what to do, contact your doctor or pharmacist for advice.
Overdose
If you have taken more tablets than prescribed, stop taking Xospata and contact your doctor immediately or go to the nearest emergency department. Taking too many tablets may increase the risk of serious side effects, including cardiac complications and severe drops in blood cell counts. Bring the medication packaging with you so that healthcare professionals can identify the drug and the amount taken.
Stopping Treatment
Do not stop taking Xospata unless your doctor tells you to. It is important to continue treatment as prescribed, even if you are feeling better, because the therapeutic effect requires consistent drug exposure. If you have concerns about side effects or your treatment, discuss them with your doctor before making any changes to your regimen.
What Are the Side Effects of Xospata?
Like all medicines, Xospata can cause side effects, although not everybody gets them. Some side effects can be serious and require immediate medical attention, while others are more common and generally manageable. Your doctor will monitor you closely for side effects throughout your treatment and may adjust your dose, temporarily interrupt treatment, or prescribe additional medications to manage symptoms.
Serious Side Effects Requiring Immediate Medical Attention
Differentiation syndrome (may affect up to 1 in 10 people): fever, breathing difficulties, rash, dizziness or feeling faint, rapid weight gain, swelling of arms or legs. PRES (may affect up to 1 in 100 people): seizures, rapidly worsening headache, confusion, blurred vision or other visual problems. QT prolongation (may affect up to 1 in 10 people): changes in heartbeat, dizziness, light-headedness, or fainting.
Side Effects by Frequency
Very Common
May affect more than 1 in 10 people
- Diarrhea
- Nausea
- Constipation
- Fatigue and tiredness
- Swelling due to fluid retention (edema)
- Decreased energy and weakness (asthenia)
- Elevated creatine phosphokinase in blood (indicates muscle or heart function)
- Elevated liver enzymes: ALT, AST, and/or alkaline phosphatase
- Pain in arms and legs
- Joint pain (arthralgia)
- Muscle pain (myalgia)
- Cough
- Shortness of breath (dyspnea)
- Dizziness
- Low blood pressure (hypotension)
Common
May affect up to 1 in 10 people
- Fluid accumulation around the heart (pericardial effusion), which if severe may affect the heart’s ability to pump blood
- General feeling of being unwell (malaise)
- Severe, life-threatening allergic reaction (anaphylactic reaction) with swelling of mouth, tongue, face, and throat, itching, or hives
- Muscle stiffness
- Decreased urination, swelling of legs (signs of sudden kidney injury)
- Inflammation of the heart lining (pericarditis)
- Heart failure
If you experience any side effects, including any not listed above, talk to your doctor, pharmacist, or nurse. You can also report side effects directly to your national medicines regulatory authority. Reporting side effects helps to continuously monitor the benefit-risk balance of this medication and contributes to drug safety for all patients.
Many side effects of Xospata can be managed effectively with supportive care. For nausea, your doctor may recommend anti-nausea medications. For diarrhea, staying well-hydrated and using antidiarrheal agents may be advised. Fatigue is common during cancer treatment, and your doctor may suggest strategies to conserve energy and improve rest. Regular monitoring through blood tests and ECGs allows your healthcare team to detect and address potential problems early.
How Should You Store Xospata?
Proper storage of Xospata is essential to maintain the effectiveness and safety of the medication. The following guidelines should be followed at all times:
- Keep out of sight and reach of children. Store the tablets in a safe location where children cannot access them.
- Do not use after the expiry date. The expiry date is printed on the carton and blister pack after “EXP.” The expiry date refers to the last day of the stated month.
- Store in the original packaging. Xospata is sensitive to light and should be kept in its original blister packaging until you are ready to take a dose.
- No special temperature requirements. Store at room temperature unless otherwise specified on the packaging.
- Proper disposal. Do not throw unused medicines in the drain or household waste. Ask your pharmacist how to dispose of medicines you no longer use. These measures help protect the environment.
What Does Xospata Contain?
Active Ingredient
The active substance is gilteritinib. Each film-coated tablet contains 40 mg of gilteritinib (as fumarate). Gilteritinib fumarate is the salt form of the active molecule, which ensures optimal stability and absorption in the body.
Other Ingredients
The other ingredients (excipients) in Xospata 40 mg film-coated tablets are:
- Tablet core: mannitol (E421), hydroxypropylcellulose, low-substituted hydroxypropylcellulose, magnesium stearate
- Film coating: hypromellose, talc, macrogol, titanium dioxide, yellow iron oxide (E172)
Appearance and Packaging
Xospata 40 mg film-coated tablets are round, light yellow tablets with the company logo and “235” embossed on one side. The tablets are provided in blister packs and are available in packs containing 84 film-coated tablets (4 blister packs of 21 tablets each).
The marketing authorization holder is Astellas Pharma Europe B.V., based in Leiden, the Netherlands. The tablets are manufactured by Delpharm Meppel B.V. in Meppel, the Netherlands. For further information about this medicine, please refer to the European Medicines Agency (EMA) website or the FDA prescribing information.
Frequently Asked Questions About Xospata
FLT3-mutated acute myeloid leukemia is a subtype of AML in which the cancer cells carry a mutation in the FLT3 gene. This mutation causes the FLT3 receptor to be constantly activated, driving rapid and uncontrolled growth of leukemic cells. FLT3 mutations occur in approximately 25–30% of AML patients and are associated with a higher risk of relapse and generally poorer outcomes compared with FLT3-negative AML. Because Xospata specifically targets the mutated FLT3 receptor, your doctor must confirm that your AML carries a FLT3 mutation (ITD or TKD type) using a validated diagnostic test before starting treatment. This targeted approach allows Xospata to be effective in this specific patient population.
The duration of Xospata treatment varies depending on your individual response to therapy, disease status, and tolerance of side effects. Your doctor will determine how long you should continue taking Xospata. Treatment is typically continued for as long as you benefit from it and can tolerate the medication. It is important not to stop treatment without consulting your doctor, as the therapeutic effect may take time to fully develop. In the pivotal ADMIRAL clinical trial, patients received gilteritinib for a median duration of approximately 4–5 months, though some patients continued treatment for much longer.
Yes, Xospata can be taken with or without food. There are no specific dietary restrictions associated with this medication. However, you should swallow the tablets whole with water and avoid splitting, crushing, or chewing them. It is recommended to take your dose at the same time each day to maintain consistent drug levels in your blood and to help you remember to take it. Some patients find it helpful to associate taking their medication with a daily routine, such as a meal or bedtime.
If you experience symptoms of differentiation syndrome — such as unexplained fever, breathing difficulties, skin rash, dizziness, feeling faint, rapid weight gain, or swelling of your arms or legs — contact your doctor immediately or go to the nearest emergency department. Differentiation syndrome can occur at any time during the first 3 months of treatment, sometimes within the first day. Your doctor will evaluate your condition and may prescribe corticosteroids to control the symptoms. Xospata treatment may be temporarily interrupted until symptoms improve. Always carry your patient alert card and show it to any healthcare professional you encounter.
Currently, Xospata is approved for the treatment of relapsed or refractory FLT3-mutated AML, meaning it is used when the disease has come back after or not responded to previous treatment. It is not currently approved as a first-line (initial) treatment for newly diagnosed AML. However, research into the use of gilteritinib in earlier treatment settings, including combination regimens with chemotherapy for newly diagnosed patients, is ongoing. Your doctor will determine the most appropriate treatment for your specific situation based on international guidelines and your individual medical history.
Regular monitoring is essential during Xospata treatment. Your doctor will perform blood tests before and periodically during treatment to check your blood cell counts (complete blood count), liver function (ALT, AST, alkaline phosphatase), electrolyte levels (particularly potassium and magnesium), and kidney function. Electrocardiograms (ECGs) will be performed before starting treatment and at regular intervals during treatment to monitor for QT prolongation. Your doctor will also monitor you for signs of differentiation syndrome, especially during the first 3 months. If you develop any new or worsening symptoms, report them to your healthcare team promptly.
References
- European Medicines Agency (EMA). Xospata (gilteritinib) – Summary of Product Characteristics. Last updated 2024. Available at: www.ema.europa.eu
- U.S. Food and Drug Administration (FDA). Xospata (gilteritinib) – Prescribing Information. Revised 2024. Available at: www.fda.gov
- Perl AE, Martinelli G, Cortes JE, et al. Gilteritinib or chemotherapy for relapsed or refractory FLT3-mutated AML. N Engl J Med. 2019;381(18):1728–1740. doi:10.1056/NEJMoa1902688
- National Comprehensive Cancer Network (NCCN). Clinical Practice Guidelines in Oncology: Acute Myeloid Leukemia. Version 1.2025. Available at: www.nccn.org
- Döhner H, Wei AH, Appelbaum FR, et al. Diagnosis and management of AML in adults: 2022 recommendations from an international expert panel on behalf of the ELN. Blood. 2022;140(12):1345–1377. doi:10.1182/blood.2022016867
- World Health Organization (WHO). Model List of Essential Medicines. 23rd List, 2023. Geneva: WHO; 2023.
- European Society for Medical Oncology (ESMO). Acute Myeloid Leukemia: ESMO Clinical Practice Guidelines. Ann Oncol. 2024.
- British National Formulary (BNF). Gilteritinib. Available at: bnf.nice.org.uk
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