Mirdametinib

WHY is this medicine prescribed?

Mirdametinib is used to treat certain forms of neurofibromatosis type 1 (NF1; a genetic disorder that causes benign tumors to grow on nerves). Mirdametinib is in a class of medications called kinase inhibitors. It works by reducing the size and number of tumors.

Are there OTHER USES for this medicine?

This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.

HOW should this medicine be used?

Mirdametinib comes as a tablet and capsule to take by mouth. Take with or without food twice a day for 21 days. Take mirdametinib at around the same times every day. You will have 7 days off and then repeat this cycle. Your doctor will determine how many cycles you should receive.

Take mirdametinib exactly as directed. Ask your doctor or pharmacist to explain any part you do not understand. Do not take more or less of it or take it more often than prescribed by your doctor.

Swallow the capsules whole; do not split, chew, or crush them.

The tablets can be swallowed whole. If you are unable to swallow the tablet, you can add the tablet(s) to 1 to 2 teaspoons (5 to 10 mL) of drinking water in a cup. Gently swirl the contents of the cup until the tablets are fully dissolved (about 2 to 4 minutes). The contents may look cloudy and white. Drink all of the contents or give with an oral syringe. Then add 1 to 2 more teaspoons (5 to 10 mL) of water, gently swirl the contents to mix and then drink all of the contents in the cup or administer by oral syringe. If the dissolved tablet and water have not been taken by 30 minutes, it must be thrown away.

It is important to tell your doctor how you are feeling during treatment. Your doctor may need to change your dose to stop or lessen side effects.

Your doctor will have you get an eye exam and an echocardiogram (a medical imaging test used to look at your heart) before and periodically during mirdametinib treatment. Make sure you do not miss these appointments.

What SPECIAL PRECAUTIONS should I follow?

Before taking mirdametinib,

• tell your doctor or pharmacist if you are allergic to this drug, any part of this drug, or any other drugs, foods or substances. Tell your doctor or pharmacist about the allergy and what symptoms you had.

• tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take.

• tell your doctor if you have or have ever had kidney disease, liver disease, or heart disease. Tell your doctor is you have a history of eye disease.

• tell your doctor if you or your partner are pregnant or plan to become pregnant. Mirdametinib may harm the fetus. You may be required to have a pregnancy test prior to starting treatment. If you are able to become pregnant, use effective contraception during and for 6 weeks after mirdametinib treatment. If your partner is able to become pregnant, use effective contraception during and for 3 months after mirdametinib treatment. Talk to your doctor about what contraception is best for you.

• do not breastfeed during and for 1 week after mirdametinib treatment.

What SPECIAL DIETARY instructions should I follow?

Unless your doctor tells you otherwise, continue your normal diet.

What should I do IF I FORGET to take a dose?

If you miss a dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one. If you vomit after taking a dose, do not take another dose. Continue your regular dosing schedule.

What SIDE EFFECTS can this medicine cause?

Mirdametinib may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• rash (redness of skin, presence of flat or raised bumps), dry or itchy skin
• loss of hair
• loose stools
• nausea and/or vomiting
• stomach pain
• swelling, redness, pain or sores of the lips, gums, tongue or cheeks
• muscle or joint aches or pains
• tiredness
• fever
• runny nose, sneezing, sinus or chest congestion, and/or cough
• redness and/or swelling of the nail beds on toes or fingers
• headache
• numbness, tingling, pain or burning in hands feet or legs

Some side effects can be serious. If you experience any of these symptoms, call your doctor immediately or get emergency medical treatment:

• blurred vision, floaters (dark spots) in line of vision, vision loss, pain or pressure in the eye, redness of the eye, flashes of light, disturbances in vision, loss of peripheral vision
• shortness of breath, feeling tired or weak, cough, chest pain, swelling in the legs or feet, weight gain, abdominal bloating, upper right-sided stomach pain
• rash with peeling skin

Mirdametinib may cause infertility in people with female reproductive organs. Talk to your doctor about the risks of taking this medication.

Mirdametinib may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.

If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online (https://www.fda.gov/Safety/MedWatch) or by phone (1-800-332-1088).

What should I know about STORAGE and DISPOSAL of this medication?

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from light, excess heat and moisture (not in the bathroom).

Keep all medication out of sight and reach of children as many containers are not child-resistant. Always lock safety caps. Place the medication in a safe location – one that is up and away and out of their sight and reachhttps://www.upandaway.org

Dispose of unneeded medications in a way so that pets, children, and other people cannot take them. Do not flush this medication down the toilet. Use a medicine take-back program. Talk to your pharmacist about take-back programs in your community. Visit the FDA's Safe Disposal of Medicines website https://goo.gl/c4Rm4p for more information. In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online at https://www.poisonhelp.org/help. If the victim has collapsed, had a seizure, has trouble breathing, or can't be awakened, immediately call emergency services at 911.

What should I do in case of OVERDOSE?

In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online at https://www.poisonhelp.org/help. If the victim has collapsed, had a seizure, has trouble breathing, or can't be awakened, immediately call emergency services at 911.

What OTHER INFORMATION should I know?

Keep all appointments with your doctor, the laboratory, medical imaging and eye doctors. Your doctor will order certain lab and imaging tests to check your body's response to mirdametinib.

Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.

Keep a written list of all of the prescription and nonprescription (over-the-counter) medicines vitamins, minerals, and dietary supplements you are taking. Bring this list with you each time you visit a doctor or if you are admitted to the hospital. You should carry the list with you in case of emergencies.