The FIRST and ONLY FDA-approved medication proven to reduce the size of PN*

*66% or 33 of 50 patients in the clinical study saw a 20% or more decrease in the size of their plexiform neurofibromas, confirmed by 3D magnetic resonance imaging (MRI) scan.

KOSELUGO® (selumetinib) is a prescription medicine that is used to treat children 2 years of age and older with neurofibromatosis type 1 (NF1) who have plexiform neurofibromas that cannot be completely removed by surgery. It is not known if Koselugo is safe and effective in children under 2 years of age.

Koselugo comes with a team

Koselugo comes with a team

Connect with a Patient Education Manager (PEM) to get personal one-to-one support. PEMs are just one of the resources available through OneSource.

Find your PEM

Educational events

Educational events

Explore live and virtual events that cover a range of topics that can help in the care of your child with NF1 PN. Registering is simple and free. Get started today.

See events

IMPORTANT SAFETY INFORMATION

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 could become pregnant and males with female partners who could become pregnant 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
  • Tell your healthcare provider right away if you become pregnant or think you may be pregnant during treatment with Koselugo
    • 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. Especially tell your healthcare provider if you are taking aspirin, blood thinners, or other medicines to treat blood clots. Koselugo contains vitamin E, which may increase your risk of bleeding.

Koselugo may cause serious side effects, including:
Heart problems.
Koselugo can lower the amount of blood pumped by your heart, which is common and can also 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 any of the following signs or symptoms:

  • blurred vision
  • loss of vision
  • dark spots in your vision (floaters)
  • other changes to your vision

Severe diarrhea. Diarrhea is common with Koselugo and can also be severe. 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 rash. Skin rashes are common with Koselugo and can also be severe. Tell your healthcare provider if you get any of the following signs or symptoms:

  • rash that covers a large area of your body
  • peeling skin
  • blisters

Muscle problems (rhabdomyolysis). Muscle problems are common with Koselugo and can also be severe. Treatment with Koselugo may increase the level of a muscle enzyme in your blood, which may be a sign of muscle damage. Your healthcare provider should do a blood test to check your muscle enzyme levels before you start taking Koselugo and during treatment. 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 ask you to stop taking Koselugo if you have any of these side effects.

The most common side effects of Koselugo are:

  • vomiting
  • stomach-area pain
  • nausea
  • dry skin
  • muscle and bone pain
  • feeling of tiredness or lacking energy
  • fever
  • sores in your mouth
  • headache
  • redness around the fingernails
  • itching

These are not all the possible side effects of Koselugo.

  • are pregnant or plan to become pregnant. Koselugo can harm your unborn baby
    • Females who could become pregnant and males with female partners who could become pregnant 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
  • Tell your healthcare provider right away if you become pregnant or think you may be pregnant during treatment with Koselugo
    • 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. Especially tell your healthcare provider if you are taking aspirin, blood thinners, or other medicines to treat blood clots. Koselugo contains vitamin E, which may increase your risk of bleeding.

Koselugo may cause serious side effects, including:
Heart problems.
Koselugo can lower the amount of blood pumped by your heart, which is common and can also 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 any of the following signs or symptoms:

  • blurred vision
  • loss of vision
  • dark spots in your vision (floaters)
  • other changes to your vision

Severe diarrhea. Diarrhea is common with Koselugo and can also be severe. 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 rash. Skin rashes are common with Koselugo and can also be severe. Tell your healthcare provider if you get any of the following signs or symptoms:

  • rash that covers a large area of your body
  • peeling skin
  • blisters

Muscle problems (rhabdomyolysis). Muscle problems are common with Koselugo and can also be severe. Treatment with Koselugo may increase the level of a muscle enzyme in your blood, which may be a sign of muscle damage. Your healthcare provider should do a blood test to check your muscle enzyme levels before you start taking Koselugo and during treatment. 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 ask you to stop taking Koselugo if you have any of these side effects.

The most common side effects of Koselugo are:

  • vomiting
  • stomach-area pain
  • nausea
  • dry skin
  • muscle and bone pain
  • feeling of tiredness or lacking energy
  • fever
  • sores in your mouth
  • headache
  • redness around the fingernails
  • itching

These are not all the possible side effects of Koselugo.