What is Gilteritinib: Uses, Dosage, Side Effects and More

Gilteritinib is a targeted cancer medication that helps treat a specific type of acute myeloid leukemia (AML). This oral medicine works by blocking certain proteins that help cancer cells grow and multiply, giving your body a better chance to fight the disease.

If you or someone you care about has been prescribed gilteritinib, it's natural to have questions about how it works and what to expect. This medication represents an important advance in treating AML, particularly for people whose cancer has a specific genetic change called an FLT3 mutation.

What is Gilteritinib?

Gilteritinib is a prescription medication that belongs to a class of drugs called kinase inhibitors. It specifically targets and blocks proteins called FLT3 and AXL that cancer cells use to grow and survive.

This medication comes as tablets that you take by mouth, making treatment more convenient than some other cancer therapies. Your doctor will prescribe gilteritinib based on your specific type of leukemia and whether your cancer cells have certain genetic markers that make this treatment effective.

The medication works inside your body to disrupt the signals that tell cancer cells to multiply. By blocking these pathways, gilteritinib can help slow down or stop the growth of leukemia cells while allowing your healthy blood cells to recover.

What is Gilteritinib Used For?

Gilteritinib is primarily used to treat adults with acute myeloid leukemia (AML) that has specific genetic changes called FLT3 mutations. Your doctor will use this medication when your leukemia has either returned after previous treatment or hasn't responded well to other therapies.

AML is a type of blood cancer that affects your bone marrow, where your body makes blood cells. When you have AML, your bone marrow produces too many abnormal white blood cells that don't work properly, crowding out healthy blood cells.

The FLT3 mutation occurs in about 30% of people with AML. This genetic change makes certain proteins overactive, causing cancer cells to grow more rapidly. Gilteritinib specifically targets these overactive proteins, which is why your doctor needs to test your cancer cells before prescribing this medication.

How Does Gilteritinib Work?

Gilteritinib works by blocking specific proteins called FLT3 and AXL that act like switches inside cancer cells. When these proteins are turned on, they send signals telling the cancer cells to grow, multiply, and survive.

Think of these proteins as fuel pumps that keep cancer cells running. Gilteritinib acts like a shut-off valve, stopping the fuel supply that cancer cells need to thrive. This targeted approach is considered a moderate to strong cancer treatment, as it directly interferes with the cancer's growth mechanisms.

Unlike chemotherapy that affects all rapidly dividing cells, gilteritinib is designed to be more selective. It primarily targets cells with the FLT3 mutation, which can help reduce some side effects while still being effective against your leukemia.

How Should I Take Gilteritinib?

Take gilteritinib exactly as your doctor prescribes, typically once daily at about the same time each day. You can take it with or without food, but try to be consistent with your choice to help your body absorb the medication predictably.

Swallow the tablets whole with a glass of water. Don't crush, chew, or break the tablets, as this can affect how the medication works in your body. If you have trouble swallowing pills, talk to your healthcare team about strategies that might help.

It's best to take gilteritinib when your stomach isn't completely empty. Having a light snack or meal before taking your dose can help reduce stomach upset. Avoid grapefruit and grapefruit juice while taking this medication, as they can increase the amount of drug in your bloodstream to potentially harmful levels.

Keep taking gilteritinib even on days when you don't feel well, unless your doctor tells you to stop. Consistency is important for the medication to work effectively against your leukemia.

How Long Should I Take Gilteritinib For?

The length of gilteritinib treatment varies significantly from person to person and depends on how well your leukemia responds to the medication. Some people may take it for several months, while others might need it for a year or longer.

Your doctor will monitor your progress through regular blood tests and bone marrow examinations. These tests help determine whether the medication is working and whether your body is tolerating it well. Based on these results, your doctor will decide whether to continue, adjust, or stop your treatment.

Never stop taking gilteritinib on your own, even if you're feeling better. Leukemia can return quickly if treatment is stopped too early. Your healthcare team will guide you through any changes to your treatment plan based on your individual response and overall health.

What Are the Side Effects of Gilteritinib?

Like all cancer medications, gilteritinib can cause side effects, though not everyone experiences them. Most side effects are manageable with proper care and monitoring from your healthcare team.

Understanding what to expect can help you feel more prepared and know when to reach out for support. Here are the most common side effects you might experience:

• Fatigue and weakness: This is very common and may feel more intense than regular tiredness
• Muscle and joint pain: You might feel aches similar to having the flu
• Swelling: Your hands, feet, or face might retain fluid
• Shortness of breath: You may feel winded more easily than usual
• Nausea and decreased appetite: Food might not seem appealing
• Diarrhea: Bowel movements may become loose or more frequent
• Dizziness: You might feel lightheaded when standing up

These side effects often improve as your body adjusts to the medication. Your healthcare team can provide strategies to help manage these symptoms and maintain your quality of life during treatment.

Some people may experience more serious side effects that require immediate medical attention. While these are less common, it's important to be aware of them:

• Heart problems: Chest pain, irregular heartbeat, or severe shortness of breath
• Severe fluid retention: Rapid weight gain or difficulty breathing
• Liver problems: Yellowing of skin or eyes, dark urine, or severe stomach pain
• Serious infections: Fever, chills, or signs of infection when your immune system is weakened
• Bleeding problems: Unusual bruising or bleeding

Contact your healthcare team immediately if you experience any of these serious symptoms. They're equipped to help you manage these effects and adjust your treatment if needed.

Who Should Not Take Gilteritinib?

Gilteritinib isn't suitable for everyone, and your doctor will carefully evaluate whether it's right for you. People with certain health conditions or taking specific medications may not be good candidates for this treatment.

Your doctor will consider several factors before prescribing gilteritinib to ensure it's safe for your specific situation:

• Pregnancy and breastfeeding: This medication can harm an unborn baby or nursing infant
• Severe heart problems: Existing heart conditions may worsen with treatment
• Severe liver disease: Your liver needs to process this medication effectively
• Severe kidney problems: Your kidneys help eliminate the drug from your body
• Active serious infections: The medication can weaken your immune system further
• Certain other medications: Some drugs can interact dangerously with gilteritinib

Be sure to tell your doctor about all medications, supplements, and herbal products you're taking. Also mention any pregnancy plans, as both men and women need to use effective birth control during treatment and for some time afterward.

Your healthcare team will work with you to determine if gilteritinib is appropriate for your situation and monitor you closely throughout treatment.

Gilteritinib Brand Name

Gilteritinib is sold under the brand name Xospata. This is the only brand name currently available for this medication in the United States.

When you pick up your prescription, you'll see "Xospata" on the bottle label along with "gilteritinib" as the generic name. Both names refer to the same medication, so don't worry if you see either one used in your medical records or discussions with your healthcare team.

Currently, there are no generic versions of gilteritinib available. This means Xospata is the only option, which may affect insurance coverage and cost considerations that you can discuss with your healthcare team and pharmacy.

Gilteritinib Alternatives

Several other medications can treat AML, though the best choice depends on your specific type of leukemia and individual health factors. Your doctor will consider your cancer's genetic makeup, your overall health, and previous treatments when exploring alternatives.

Other targeted therapies for AML include midostaurin (another FLT3 inhibitor) and various combinations of traditional chemotherapy drugs. Some people might be candidates for newer treatments like venetoclax combined with other medications.

For some patients, clinical trials might offer access to experimental treatments that aren't yet widely available. Your healthcare team can help you understand all your options and determine the best approach for your specific situation.

The choice of treatment is highly individual, and what works best for one person may not be ideal for another. Trust your healthcare team to guide you through these decisions based on the latest research and your personal health profile.

Is Gilteritinib Better Than Midostaurin?

Both gilteritinib and midostaurin are FLT3 inhibitors, but they're typically used in different situations rather than being directly compared as better or worse options. The choice between them depends on your specific circumstances and treatment history.

Midostaurin is often used alongside chemotherapy as initial treatment for newly diagnosed AML with FLT3 mutations. Gilteritinib, on the other hand, is typically reserved for people whose AML has returned after previous treatment or hasn't responded to other therapies.

Some studies suggest that gilteritinib might be more potent at blocking FLT3 proteins, but this doesn't automatically make it better for everyone. Your doctor considers many factors including your overall health, previous treatments, and how your specific cancer behaves when choosing the right medication.

The most important thing is finding the treatment that works best for your individual situation. Your healthcare team will help you understand why they've chosen one medication over another based on current research and your personal medical history.