Koselugo 10mg Capsule contains Selumetinib. It is used to treat symptomatic, inoperable plexiform neurofibromas in people with neurofibromatosis type 1 (NF1). These are tumours that grow along nerves and may cause pain, movement problems, or other complications.

Selumetinib blocks MEK proteins involved in signals that control cell growth. This helps slow the growth of plexiform neurofibromas and may reduce their size and related symptoms.

The dose of Koselugo is based on body surface area and is usually taken twice a day. The 10mg and 25mg capsules may be used together to give the prescribed dose. Take Koselugo only as advised by your doctor.

• Neurofibromatosis type 1 (NF1) with symptomatic, inoperable plexiform neurofibromas

Koselugo 10mg Capsule contains Selumetinib, which blocks MEK1 and MEK2 proteins involved in the MAPK pathway. This pathway helps control cell growth. Blocking these signals can slow the growth of plexiform neurofibromas associated with NF1.

Tell your doctor about all the medicines, vitamins, supplements, and herbal products you take.

Some medicines can change the amount of Selumetinib in your body and increase the risk of side effects or reduce its effect. Medicines that affect liver enzymes such as CYP3A4 and CYP2C19 may interact with Koselugo.

Koselugo capsules also contain vitamin E. Tell your doctor if you take blood thinners or medicines that affect blood clotting, as this may increase the risk of bleeding. Avoid taking additional vitamin E supplements unless advised by your doctor.

• Store Koselugo 10mg Capsule in the original bottle.

• Keep the bottle tightly closed.

• Protect it from moisture and light.

• Do not store above 30°C.

• Keep out of reach of children.

Take Koselugo 10mg Capsule exactly as prescribed by your doctor. It is usually taken twice a day, about 12 hours apart.

Swallow the capsule whole with water. Do not open, crush, chew, or dissolve it. Koselugo capsules can be taken with or without food.

The dose is calculated according to body surface area. Your doctor may prescribe the 10mg and 25mg capsules together to provide the required dose.

If you miss a dose, take it when you remember only if more than 6 hours remain before your next dose. If less than 6 hours remain, skip the missed dose and take the next dose at the usual time. Do not take two doses together. If you vomit after taking a dose, do not take another dose.

Like all medicines, Koselugo 10mg Capsule can cause side effects, although not everyone gets them.

Common side effects:

• Vomiting

• Diarrhoea

• Nausea

• Skin rash

• Acne-like rash

• Dry skin

• Increased creatine phosphokinase (CPK) levels

• Nail problems

• Tiredness

• Fever

Serious side effects:

• Heart problems

• Eye problems

• Liver problems

• Severe skin reactions

• Muscle problems

• Bleeding

Contact your doctor if you develop new vision problems, severe diarrhoea or vomiting, unusual bleeding, severe muscle pain or weakness, yellowing of the skin or eyes, or breathing difficulties.

• Take Koselugo exactly as prescribed by your doctor.

• Do not change the dose or stop treatment without medical advice.

• Your doctor may regularly check your heart function, eyes, and liver during treatment.

• Tell your doctor about all medicines and supplements you take.

• Avoid additional vitamin E supplements unless your doctor recommends them.

• Tell your doctor if you take blood thinners or medicines that affect blood clotting.

• Report new vision changes, breathing problems, severe diarrhoea, unusual bleeding, or severe muscle pain to your doctor.

1. https://www.ema.europa.eu/en/documents/product-information/koselugo-epar-product-information_en.pdf

2. https://www.medicines.org.uk/emc/product/12948/pil

3. https://www.accessdata.fda.gov/drugsatfda_docs/label/2025/213756Orig1s005lbl.pdf