Midostaurin

Say it: mye-doe-STAW-rin · Brand names: Rydapt

Midostaurin is a targeted pill that blocks signals that help certain leukemia cells and mast cells grow.

What it is

Some leukemia cells have a change in a gene called FLT3 (FMS-like tyrosine kinase 3) that sends nonstop grow signals. Midostaurin blocks this signal and a few others, including one called KIT that drives a rare mast cell disease. It is given along with chemotherapy for leukemia.

Often used for

• newly diagnosed acute myeloid leukemia (AML) with a FLT3 gene change, with chemotherapy
• advanced systemic mastocytosis (a rare disease of mast cells)

How you get it

Midostaurin is a capsule you take by mouth twice a day, about 12 hours apart, with food. For acute myeloid leukemia, it is taken on certain days of each chemotherapy cycle. For mastocytosis, it is taken every day. Your schedule may be different.

Common side effects and what helps

• Nausea and vomiting. You will take anti-nausea medicine before each dose.
• Mouth sores. Rinse with a mild salt and baking soda mouthwash and use a soft toothbrush.
• Fever with low white blood cells. Call your team right away if you get a fever.
• Headache. Ask your team what pain medicine is safe.
• Muscle or bone pain. Gentle stretching and warm baths may help.
• Nosebleeds. Pinch your nose and lean forward. Tell your team if they last.
• High blood sugar. Your team will check this with blood tests.

Call your care team right away if you have

• A fever of 100.4 degrees Fahrenheit (38 degrees Celsius) or higher, or chills
• New or worse cough, shortness of breath or chest discomfort
• Bleeding that will not stop, black or bloody stools, vomiting blood, or coughing up blood
• Vomiting that will not stop, or you cannot keep fluids down
• Swelling of the face or throat, or trouble breathing

Before you start, tell your team

• If you have lung or breathing problems
• If you have heart problems
• If you are pregnant, may become pregnant, or are breastfeeding
• All the medicines you take, including vitamins, herbs and supplements

Good to know

• Midostaurin can rarely cause serious lung inflammation. Tell your team about any new breathing problems.
• Some antifungal and other medicines can raise midostaurin levels. Check with your team before starting anything new.
• It can harm an unborn baby. Use birth control during treatment and for at least 4 months after the last dose.
• You will have regular blood tests to check your blood counts.

At home

• Take it twice a day, about 12 hours apart, with food.
• Take your anti-nausea medicine before each dose as your team tells you.
• Swallow capsules whole. Do not open or crush them.
• If you miss a dose, ask your care team what to do. Do not take two doses to make up for it.
• Store in the original package at room temperature, away from children.

Questions to ask

• Which days of each cycle should I take it?
• What anti-nausea medicine should I take?
• How will we check if it is working?
• Which of my other medicines could interact with it?

Part of these treatment plans

• 7+3
• HiDAC

Side effect guides

• Nausea and vomiting
• Mouth sores
• Low white blood cells and infection risk
• Pain

Last updated: 2026-10-27. Medically reviewed by Veli Bakalov, MD, medical oncologist (October 2026). General education from Step by Step, the patient portal of HemeOncBuddy.