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

Quizartinib is a targeted cancer medication specifically designed to treat a particular type of acute myeloid leukemia (AML). This oral medication works by blocking abnormal proteins that help cancer cells grow and multiply in your bone marrow.

If you or a loved one has been prescribed quizartinib, you're likely dealing with a complex cancer diagnosis. While this can feel overwhelming, understanding how this medication works can help you feel more prepared and confident in your treatment journey.

What is Quizartinib?

Quizartinib is a prescription cancer medication that belongs to a class of drugs called kinase inhibitors. It specifically targets and blocks a protein called FLT3, which can become overactive in certain types of blood cancer.

This medication comes as an oral tablet, which means you can take it by mouth at home rather than needing intravenous treatments at a hospital. The drug was specifically developed for people whose acute myeloid leukemia has a particular genetic mutation called FLT3-ITD.

Your doctor will have tested your cancer cells to confirm you have this specific mutation before prescribing quizartinib. This personalized approach helps ensure the medication will be most effective for your particular type of leukemia.

What is Quizartinib Used For?

Quizartinib is used to treat adults with acute myeloid leukemia (AML) that has a specific genetic change called FLT3-ITD mutation. This medication is typically prescribed when your leukemia has either come back 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 this condition, your bone marrow produces too many abnormal white blood cells that don't work properly, crowding out healthy blood cells.

The FLT3-ITD mutation makes the cancer cells grow and multiply more aggressively. About 25-30% of people with AML have this particular mutation, which is why genetic testing is so important before starting treatment.

Your oncologist may also consider quizartinib if you're not a candidate for intensive chemotherapy due to your age or other health conditions. This medication offers a targeted approach that can be gentler on your body while still fighting the cancer effectively.

How Does Quizartinib Work?

Quizartinib works by blocking a specific protein called FLT3 that acts like a "growth switch" for cancer cells. When this protein is mutated, it stays turned on all the time, telling cancer cells to keep growing and dividing rapidly.

Think of it like a car with a stuck accelerator pedal. The FLT3 mutation keeps the "accelerator" pressed down, making cancer cells multiply out of control. Quizartinib acts like applying the brakes, stopping this runaway growth process.

This medication is considered a strong and effective targeted therapy. Unlike traditional chemotherapy that affects all rapidly dividing cells, quizartinib specifically targets the mutated protein in your cancer cells, which can mean fewer side effects on healthy cells.

Once you take the medication, it travels through your bloodstream and reaches the bone marrow where the leukemia cells are growing. By blocking the FLT3 protein, it can help reduce the number of cancer cells and allow your bone marrow to start producing healthier blood cells again.

How Should I Take Quizartinib?

You should take quizartinib exactly as your doctor prescribes, typically once daily at the same time each day. The medication comes as tablets that you swallow whole with a full glass of water.

You can take quizartinib with or without food, but try to be consistent with your choice. If you usually take it with breakfast, continue doing so throughout your treatment. This helps maintain steady levels of the medication in your system.

Don't crush, chew, or break the tablets, as this can affect how the medication is absorbed. If you have trouble swallowing pills, talk to your healthcare team about strategies that might help, but never alter the tablets themselves.

It's important to take quizartinib at roughly the same time every day to maintain consistent levels in your bloodstream. Setting a daily alarm or linking it to a routine activity like brushing your teeth can help you remember.

Store your medication at room temperature, away from moisture and heat. Keep it in its original container and away from children and pets.

How Long Should I Take Quizartinib For?

The length of quizartinib treatment varies significantly from person to person and depends on how well your body responds to the medication. Your doctor will monitor your progress through regular blood tests and bone marrow biopsies to determine the appropriate duration.

Many people continue taking quizartinib for several months to years, as long as it's effectively controlling their leukemia and the side effects remain manageable. Some patients may take it indefinitely as a maintenance therapy to keep their cancer in remission.

Your oncologist will regularly assess whether the medication is working by checking your blood cell counts and looking for leukemia cells in your bone marrow. If your cancer responds well, you'll likely continue treatment for an extended period.

Never stop taking quizartinib suddenly or change your dosing schedule without consulting your healthcare team. Even if you're feeling better, the medication may still be actively fighting cancer cells that aren't causing symptoms yet.

What Are the Side Effects of Quizartinib?

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

Here are the most common side effects you might experience while taking quizartinib:

• Nausea and vomiting
• Diarrhea or constipation
• Fatigue and weakness
• Decreased appetite
• Muscle and joint pain
• Headache
• Dizziness
• Changes in taste

These common side effects often improve as your body adjusts to the medication. Your healthcare team can provide strategies and medications to help manage these symptoms effectively.

More serious side effects can occur, though they're less common. It's important to be aware of these so you can seek medical attention promptly if needed:

• Heart rhythm problems (QT prolongation)
• Severe infections due to low white blood cell counts
• Bleeding or bruising due to low platelet counts
• Liver problems
• Fluid retention and swelling
• Difficulty breathing
• Severe skin reactions

Your doctor will monitor you closely with regular blood tests and heart monitoring to catch any serious side effects early. Most people can continue treatment safely with appropriate medical supervision.

Rare but serious side effects may include severe heart problems, life-threatening infections, or tumor lysis syndrome (when cancer cells break down too quickly). While these complications are uncommon, your medical team will watch for early warning signs and act quickly if they occur.

Who Should Not Take Quizartinib?

Quizartinib isn't suitable for everyone, and your doctor will carefully evaluate whether it's the right choice for you. People with certain heart conditions may not be candidates for this medication due to its potential effects on heart rhythm.

You should not take quizartinib if you have a known allergy to the medication or any of its ingredients. Your doctor will also be cautious about prescribing it if you have severe liver or kidney problems, as these organs help process the medication.

People with certain heart rhythm disorders, particularly those with long QT syndrome, may not be able to take quizartinib safely. Your doctor will likely perform an electrocardiogram (ECG) before starting treatment to check your heart rhythm.

Pregnancy and breastfeeding are important considerations. Quizartinib can harm an unborn baby, so effective contraception is essential during treatment and for some time after stopping the medication. If you're breastfeeding, you'll need to discuss alternative feeding options with your healthcare team.

Your doctor will also consider your overall health status, other medications you're taking, and any history of serious infections before prescribing quizartinib. This careful evaluation helps ensure the medication is both safe and appropriate for your specific situation.

Quizartinib Brand Name

Quizartinib is available under the brand name Vanflyta in the United States and other countries. This is the commercial name you'll see on your prescription bottle and medication packaging.

The medication was developed by Daiichi Sankyo and received approval from the FDA for treating FLT3-ITD positive AML. When your doctor prescribes quizartinib, the pharmacy will typically dispense it as Vanflyta unless they specify otherwise.

Generic versions of quizartinib are not yet available, as the medication is still relatively new and under patent protection. This means Vanflyta is currently the only form of quizartinib available for prescription.

Quizartinib Alternatives

Several alternative medications are available for treating FLT3-positive AML, each with different mechanisms of action and side effect profiles. Your oncologist will help determine which option might be best for your specific situation.

Midostaurin (Rydapt) is another FLT3 inhibitor that's often used in combination with chemotherapy for newly diagnosed FLT3-positive AML. It works similarly to quizartinib but is typically used earlier in treatment.

Gilteritinib (Xospata) is another targeted therapy for FLT3-positive AML that's used when the disease has relapsed or is refractory to other treatments. It blocks multiple proteins involved in cancer cell growth.

Traditional chemotherapy regimens remain important treatment options, particularly for people who are healthy enough to tolerate intensive treatment. These may include combinations of cytarabine and anthracyclines.

Stem cell transplantation might be considered for some patients, especially younger individuals with good overall health. This intensive treatment can potentially cure AML but requires careful patient selection and preparation.

Your doctor will consider factors like your age, overall health, previous treatments, and specific genetic characteristics of your leukemia when recommending alternatives to quizartinib.

Is Quizartinib Better Than Midostaurin?

Both quizartinib and midostaurin are effective FLT3 inhibitors, but they're typically used in different situations rather than being directly compared. The "better" choice depends on your specific circumstances, treatment history, and how your leukemia has responded to previous therapies.

Midostaurin is often used as part of initial treatment for newly diagnosed FLT3-positive AML, usually combined with standard chemotherapy. It's been shown to improve survival when added to conventional treatment regimens.

Quizartinib, on the other hand, is primarily used for relapsed or refractory FLT3-positive AML. It's designed for situations where the leukemia has come back after treatment or hasn't responded well to other therapies.

In terms of effectiveness, both medications have shown significant benefits in clinical trials. Quizartinib has demonstrated particularly strong activity against certain FLT3 mutations and may be more potent in some laboratory studies.

Side effect profiles differ between the two medications. While both can cause similar common side effects like nausea and fatigue, they may have different risks for serious complications like heart rhythm problems or infections.

Your oncologist will consider your treatment history, current health status, and specific characteristics of your leukemia when choosing between these medications. The decision isn't about which is universally "better," but rather which is most appropriate for your individual situation.