Patient information: uses, side effects, how to take - Koselugo

What is KOSELUGO?

KOSELUGO is a prescription medicine that is used to treat adults and children 1 year of age and older with neurofibromatosis type 1 (NF1) who have plexiform neurofibromas that cause symptoms and cannot be completely removed by surgery.

It is not known if KOSELUGO is safe and effective in children under 1 year of age.

Before taking KOSELUGO, tell your healthcare provider about all of your medical conditions, including if you:

have heart problems.
have eye problems.
have liver problems.
are pregnant or plan to become pregnant. KOSELUGO can harm your unborn baby.

Females who are able to become pregnant:

Your healthcare provider should check to see if you are pregnant before you begin treatment with KOSELUGO.
You should use effective birth control (contraception) during treatment with KOSELUGO and for 1 week after your last dose.
Tell your healthcare provider right away if you become pregnant or think you may be pregnant during treatment with KOSELUGO.

Males with female partners who are able to become pregnant:

- You should use effective birth control (contraception) during treatment with KOSELUGO and for 1 week after your last dose.
are breastfeeding or plan to breastfeed. It is not known if KOSELUGO passes into your breast milk.
- Do not breastfeed during treatment with KOSELUGO and for 1 week after your last dose.
- Talk to your healthcare provider about the best way to feed your baby during this time.

Tell your healthcare provider about all the medicines you take, including prescription and over-the-counter medicines, vitamins, or herbal supplements. Certain medicines may affect the way KOSELUGO works.

Especially tell your healthcare provider if you are taking a supplement containing vitamin E, aspirin, blood thinners, or other medicines to treat blood clots. KOSELUGO capsules contain vitamin E, which may increase your risk of bleeding.

How should I take KOSELUGO?

Take or give KOSELUGO exactly as your healthcare provider tells you to.
Do not change your dose or stop taking KOSELUGO unless your healthcare provider tells you to.
Your healthcare provider will decide on the right dose of KOSELUGO based on your or your child’s weight or size (body surface area).
Take or give KOSELUGO 2 times a day.
If you or your child miss a dose of KOSELUGO capsules or KOSELUGO oral granules, take or give the dose as soon as you remember, unless the next dose is due within 6 hours. If your scheduled dose is due within 6 hours, skip the dose and take or give the next dose at the regular time.
If you or your child vomit after taking a dose of KOSELUGO capsules or KOSELUGO oral granules, do not take an additional dose. Take the next dose at the regular scheduled time.

KOSELUGO comes in capsules and oral granules.

If your healthcare provider prescribes KOSELUGO capsules:
- Take KOSELUGO capsules with or without food.
- Swallow KOSELUGO capsules whole. Do not open, chew, or crush the capsules.
- Tell your healthcare provider if you or your child has trouble swallowing capsules.
If your healthcare provider prescribes KOSELUGO oral granules:
- See the Instructions for Use for the instructions on how to prepare and take or give KOSELUGO oral granules.
- Prepare KOSELUGO oral granules by carefully opening the capsule and sprinkling all of the oral granules on a small amount (about 1 to 3 teaspoons) of smooth yogurt, or fruit puree containing the following fruits: apple, banana, pear, or strawberry.
- Take or give the KOSELUGO oral granules and food mixture within 30 minutes of preparing the dose.
- If the prepared dose of KOSELUGO oral granules and food mixture is not taken or given within 30 minutes, do not take or give the prepared dose. Throw away the mixture and prepare a new dose.
- If part of a dose is taken or given within 30 minutes of preparing, throw away the remainder of the mixture and do not prepare a new dose. Take or give the full dose within 30 minutes next time.
- The KOSELUGO oral granules should flow freely. Do not use if the oral granules are clumped or stuck inside the capsule shell. Contact your pharmacy if this happens.
- Throw away the empty capsule shells after use.
- Do not swallow, chew, or dissolve the capsule shells of KOSELUGO oral granules.
- Do not chew or crush the KOSELUGO oral granules. Do not add oral granules to liquids.
- Do not mix KOSELUGO oral granules in grapefruit or any juice, fruit puree or jam containing Seville orange.

What should I avoid while taking KOSELUGO?

Avoid St John’s wort, grapefruit or grapefruit juice, and Seville orange during treatment with KOSELUGO.

What are the possible side effects of KOSELUGO?

KOSELUGO can cause serious side effects, including:

Heart problems. KOSELUGO can lower the amount of blood pumped by your heart, which can be severe. Your healthcare provider will do tests before and during treatment with KOSELUGO to check how well your heart is working. Tell your healthcare provider right away if you get any of the following signs or symptoms:

persistent coughing or wheezing
shortness of breath
swelling of your ankles and feet

tiredness
increased heart rate

Eye problems. KOSELUGO can cause eye problems that can lead to blindness. Your healthcare provider will check your vision before and during treatment with KOSELUGO. Tell your healthcare provider right away if you get new or worsening vision changes, including:

blurred vision
loss of vision

dark spots in your vision (floaters)
other changes to your vision

Stomach, intestine, and mouth (gastrointestinal) problems. KOSELUGO can cause diarrhea, vomiting, nausea, and mouth sores. Diarrhea can be severe with KOSELUGO. Tell your healthcare provider right away the first time that you get diarrhea during treatment with KOSELUGO. Your healthcare provider may give you medicine to help control your diarrhea and may tell you to drink more fluids.
Skin problems. Koselugo can cause severe skin rashes. Tell your healthcare provider if you get any of the following signs of skin problems:

rash that covers a large area of your body
flat skin rash
raised bumps on your skin
skin bumps that look like acne

blisters
peeling skin
itchy rash
hair thinning or hair loss (alopecia)

Increased level of an enzyme called creatine phosphokinase (CPK) in your blood and muscle problems. Koselugo can cause severe muscle problems. Treatment with KOSELUGO may increase the level of enzyme in your blood called creatine phosphokinase (CPK), which may be a sign of muscle damage. Increased level of CPK in the blood are common during treatment with KOSELUGO and can also be severe. Your healthcare provider should do a blood test to check your blood levels of CPK before and during treatment with KOSELUGO. Tell your healthcare provider right away if you get any of the following signs or symptoms:

muscle aches or pain
muscle spasms and weakness

dark, reddish urine

Your healthcare provider may change your dose, temporarily stop, or permanently stop treatment with KOSELUGO if you have any of these side effects.

The most common side effects of KOSELUGO in children include:

vomiting
diarrhea
increased level of an enzyme called creatine phosphokinase (CPK) in your blood
dry skin

redness around the fingernails
nausea
skin bumps that look like acne
fever

The most common side effects of KOSELUGO in adults include:

rash
diarrhea

skin bumps that look like acne

These are not all of the possible side effects of KOSELUGO.

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

How should I store KOSELUGO?

Store KOSELUGO capsules and KOSELUGO oral granules at room temperature between 68°F to 77°F (20°C to 25°C).
Do not store KOSELUGO oral granules above 86°F (30°C). Store KOSELUGO oral granules in the refrigerator between 36°F to 46°F (2°C to 8°C) if the temperature is above 86°F (30°C). KOSELUGO oral granules may clump together or stick to the capsule shell if the medicine gets too hot, and you may not get your full dose.
Keep KOSELUGO oral granules cold in a cooler bag with a cold pack if you need to take it anywhere.
The bottle of KOSELUGO capsules and KOSELUGO oral granules contain a desiccant packet to reduce moisture. Do not throw away the desiccant packet.
Keep KOSELUGO capsules and KOSELUGO oral granules in its original bottle to protect from light and moisture. Keep the bottle tightly closed.

Keep KOSELUGO and all medicines out of the reach of children.

General information about the safe and effective use of KOSELUGO.

Medicines are sometimes prescribed for purposes other than those listed in a Patient Information leaflet. Do not use KOSELUGO for a condition for which it was not prescribed. Do not give KOSELUGO to other people, even if they have the same symptoms you have. It may harm them. You can ask your pharmacist or healthcare provider for information about KOSELUGO that is written for a healthcare professional.

What are the ingredients in KOSELUGO?

Active ingredient: selumetinib.

KOSELUGO capsule inactive ingredients:

The 10 mg and 25 mg capsules contain: vitamin E polyethylene glycol succinate.
The 10 mg capsule shell contains: carnauba wax, carrageenan, hypromellose, potassium chloride, purified water, and titanium dioxide.
The 10 mg capsule printing ink contains: ammonium hydroxide, iron oxide black, propylene glycol, and shellac.
The 25 mg capsule shell contains: carnauba wax and/or corn starch, carrageenan, FD&C blue 2, ferric oxide yellow, hypromellose, potassium chloride, purified water, and titanium dioxide.
The 25 mg capsule printing ink contains: carnauba wax, FD&C Blue 2 aluminum lake, ferric oxide red, ferric oxide yellow, glyceryl monooleate, and shellac.

KOSELUGO oral granule inactive ingredients:

The 5 mg and 7.5 mg uncoated cores contain: glyceryl dibehenate and stearoyl polyoxylglycerides.
The 5 mg and 7.5 mg granule coatings contain: acetone, hypromellose acetate succinate, and stearic acid.
The 5 mg shell contains: ferric oxide yellow, hypromellose, and titanium dioxide.
The 5 mg printing ink contains: butyl alcohol, dehydrated alcohol, ferric oxide black, isopropyl alcohol, potassium hydroxide, propylene glycol, purified water, shellac, and strong ammonia solution.
The 7.5 mg shell contains: ferric oxide red, hypromellose, and titanium dioxide.
The 7.5 mg printing ink contains: butyl alcohol, dehydrated alcohol, ferric oxide black, isopropyl alcohol, potassium hydroxide, propylene glycol, purified water, shellac, and strong ammonia solution.

Distributed by: AstraZeneca Pharmaceuticals LP, Wilmington, DE 19850

For more information, go to website www.KOSELUGO.com or call 1-800-236-9933

This Patient Information has been approved by the U.S. Food and Drug Administration. Revised: 11/2025

Instructions for Use

INSTRUCTIONS FOR USE KOSELUGO^®(ko-SEL-u-go) (selumetinib) oral granules
This Instructions for Use contains information on how to take or give KOSELUGO oral granules. Read this Instructions for Use before taking or giving KOSELUGO oral granules and each time you get a refill. There may be new information. This information does not take the place of talking to your healthcare provider about your or your child’s medical condition or treatment. Talk to your healthcare provider or pharmacist if you have any questions about how to take or give KOSELUGO oral granules.
Important Information You Need to Know Before Taking or Giving KOSELUGO oral granules KOSELUGO oral granules come in capsules that must be opened before use. Do not swallow, chew, or dissolve the capsule shells. Do not chew or crush the oral granules. Do not add oral granules to liquids. Take or give KOSELUGO oral granules exactly as your healthcare provider tells you to. Do not change your dose or stop taking KOSELUGO oral granules unless your healthcare provider tells you to. Your healthcare provider will decide on the right dose of KOSELUGO based on your or your child’s weight or size (body surface area). KOSELUGO oral granules come in 2 different strengths: 5 mg and 7.5 mg. Each strength is a different color. Your healthcare provider may prescribe more than 1 strength of KOSELUGO oral granules for your or your child’s dose. Make sure that you understand how many capsules of KOSELUGO oral granules you need and what strengths to take. Your healthcare provider may change the dose, temporarily stop, or permanently stop treatment with KOSELUGO oral granules if you or your child has side effects. Take or give KOSELUGO oral granules 2 times a day. If you or your child miss a dose of KOSELUGO oral granules, take or give the dose as soon as you remember, unless the next dose is due within 6 hours. If your scheduled dose is due within 6 hours, skip the dose and take or give the next dose at the regular time. If you or your child vomits after taking a dose of KOSELUGO oral granules, do not take an additional dose. Take the next dose at the regular scheduled time. For more information about KOSELUGO oral granules, see the Patient Information leaflet. Supplies needed to prepare a dose of KOSELUGO oral granules: The prescribed number of KOSELUGO oral granules. Smooth yogurt, or fruit puree containing the following fruits: apple, banana, pear, or strawberry. A spoon or a small cup. A paper towel or plate.
Preparing KOSELUGO oral granules
Step 1: Wash and dry your hands thoroughly.
Step 2: Open the bottle(s) and take out the number of capsule(s) needed for your prescribed dose of KOSELUGO oral granules.
Step 3: Add a small amount (about 1 to 3 teaspoons) of smooth yogurt, or fruit puree containing apple, banana, pear, or strawberry onto the spoon or into a small cup. Do not mix KOSELUGO oral granules in grapefruit or any juice, fruit puree or jam containing Seville orange.
Step 4: Place the spoon or cup on the paper towel or plate. Carefully open the capsule(s) one at a time and sprinkle the entire contents of the capsule (oral granules) onto the food that is on the spoon or in the small cup. If you are using a spoon to prepare KOSELUGO oral granules, you may find it easier to prepare and take or give 1 capsule at a time. Repeat Steps 3 to 6 for each capsule until the full dose is taken or given. Do not swallow, chew, or dissolve the capsule shells. Do not chew or crush the oral granules. Do not add oral granules to liquids.	Important: The oral granules should flow freely inside the capsule. Do not use the capsule if the oral granules are clumped or stuck inside the capsule shell. Contact your pharmacy if this happens.
Taking or giving KOSELUGO oral granules
Step 5: Take or give the KOSELUGO oral granules and food mixture within 30 minutes of preparing the dose. Swallow the mixture without chewing while seated upright. Do not save for future use. Note: If you do not take or give the KOSELUGO oral granules and food mixture within 30 minutes of preparing the dose, do not take or give the mixture. Throw away the mixture and prepare a new dose. If you take or give part of the mixture within 30 minutes of preparing the dose, throw away the remainder of the mixture and do not prepare a new dose. Take or give the full dose within 30 minutes next time.
Step 6: If you used a cup to prepare KOSELUGO oral granules, add more of the same food into the cup and take or give all of the mixture to make sure you get the full dose.
Clean up Throw away empty capsule shells, used paper towel, and any spilled oral granules in your household trash. Wash your hands and all the supplies used to take or give KOSELUGO oral granules.
Storing KOSELUGO oral granules Store KOSELUGO oral granules at room temperature between 68°F to 77°F (20°C to 25°C). Do not store KOSELUGO oral granules above 86°F (30°C). Store KOSELUGO oral granules in the refrigerator between 36°F to 46°F (2°C to 8°C) if the temperature is above 86°F (30°C). KOSELUGO oral granules may clump together or stick to the capsule shell if the medicine gets too hot, and you may not get your full dose. Keep KOSELUGO oral granules cold in a cooler bag with a cold pack if you need to take it anywhere. The bottle of KOSELUGO oral granules contains a desiccant packet to reduce moisture. Do not throw away the desiccant packet. Keep KOSELUGO oral granules in its original bottle to protect from light and moisture. Keep the bottle tightly closed. Keep KOSELUGO and all medicines out of the reach of children.
Disposing of KOSELUGO oral granules Ask your pharmacist how to throw away unused doses, expired medicines, or medicines you no longer use.
Distributed by: AstraZeneca Pharmaceuticals LP, Wilmington, DE 19850 ©AstraZeneca 2025 For more information, go to website www.KOSELUGO.com or call 1-800-236-9933.