Mirdametinib

Mirdametinib is a prescription medication indicated for the treatment of adults and pediatric patients 2 years of age and older with neurofibromatosis type 1 (NF1) who have symptomatic plexiform neurofibromas (PN) not amenable to complete resection.

• Mirdametinib is available under the following different brand names: Gomekli.

Common side effects of Mirdametinib include:

• diarrhea 
• vomiting
• nausea  
• tiredness
• muscle, joint, and bone pain
• headache
• skin redness, swelling, or pain around the fingernails or toenails
• abdominal pain
• increased enzyme called creatine phosphokinase 
• decreased white blood cell (neutrophil) counts and increased creatine phosphokinase 

Serious side effects of Mirdametinib include:

• eye symptoms include blurred vision, loss of vision, and other changes to your vision 
• heart symptoms  include coughing or wheezing, tiredness, shortness of breath, increased heart rate, swelling of your ankles and feet 
• skin symptoms include flat skin rash, skin redness, raised bumps on the skin, itchy rash, skin bumps that look like acne, peeling skin

Rare side effects of Mirdametinib include:

• none 

Seek medical care or call 911 at once if you have the following serious side effects:

• Severe headache, confusion, slurred speech, arm or leg weakness, trouble walking, coordination loss, unsteady, very stiff muscles, high fever, profuse sweating, or tremors.
• Serious eye symptoms such as sudden vision loss, blurred vision, tunnel vision, eye pain or swelling, or seeing halos around lights.
• Serious heart symptoms include fast, irregular, or pounding heartbeats; fluttering in the chest; shortness of breath; sudden dizziness, lightheadedness, or passing out.

This is not a complete list of side effects and other serious side effects or health problems that may occur because of the use of this drug. Call your doctor for medical advice about serious side effects or adverse reactions. You may report side effects or health problems to FDA at 1-800-FDA-1088.

Adult and pediatric dosage

Capsule

• 1 mg
• 2 mg

Tablet for oral suspension

• 1 mg

Neurofibromatosis type 1 (NF1)

Adult dosage

• 2 mg/m2 (maximum dose, 4 mg) orally twice daily for 21 days of each 28-day cycle
• Body surface area (BSA) dosing
  • BSA less than 1.50 m2: 3 mg orally twice daily for 21 days of each 28-day cycle
  • BSA of 1.50 m2 and more:  4 mg orally twice daily for 21 days of each 28-day cycle
  • Continue until disease progression or unacceptable toxicity

Pediatric dosage

• 2 mg/m2 (maximum dose, 4 mg) orally twice daily for 21 days of each 28-day cycle
• Body surface area (BSA) dosing
  • BSA less than 0.4 m2: Dosage not established
  • BSA between 0.4 to 0.69 m2: 1 mg orally twice daily for 21 days of each 28-day cycle
  • BSA between 0.7 to 1.04 m2: 2 mg orally twice daily for 21 days of each 28-day cycle
  • BSA between 1.05 to 1.49 m2: 3 mg orally twice daily for 21 days of each 28-day cycle
  • BSA of 1.50 m2 and more: 4 mg orally twice daily for 21 days of each 28-day cycle
  • Continue until disease progression or unacceptable toxicity

Dosage Considerations – Should be Given as Follows: 

• See “Dosages”

If your medical doctor is using this medicine to treat your pain, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor, health care provider, or pharmacist first.

• Mirdametinib has no noted severe interactions with any other drugs
• Mirdametinib has no noted serious interactions with any other drugs
• Mirdametinib has no noted moderate interactions with any other drugs
• Mirdametinib has no noted minor interactions with any other drugs

This information does not contain all possible interactions or adverse effects. Visit the RxList Drug Interaction Checker for any drug interactions. Therefore, before using this product, tell your doctor or pharmacist about all the products you use. Keep a list of all your medications with you and share this information with your doctor and pharmacist. Check with your healthcare professional or doctor for additional medical advice, health questions, or concerns.

Contraindications

• None

Effects of drug abuse

• None

Short-Term Effects

• See “What Are Side Effects Associated with Using Mirdametinib?”

Long-Term Effects

• See “What Are Side Effects Associated with Using Mirdametinib?”

Cautions

• Ocular toxicity
  • Can cause ocular toxicity (e.g., retinal vein occlusion (RVO), retinal pigment epithelium detachment (RPED), blurred vision)
  • Conduct comprehensive ophthalmic assessments before starting therapy, at regular intervals during therapy, and for any new or worsening visual changes, such as blurred vision
  • Continue, hold, dose reduce, or permanently discontinue as clinically indicated
• Left ventricular dysfunction (LVD)
  • Can cause LVD
  • Not studied in patients with a history of clinically significant cardiac disease or left ventricular ejection fraction (LVEF) below 55% at baseline
  • Assess LVEF by echocardiogram before starting therapy
  • Monitor LVEF every 3 months during the first year and then as clinically indicated
  • Hold, reduce the dose, or permanently discontinue based on severity
• Dermatologic toxicity
  • Can cause dermatologic adverse reactions (e.g., rash)
  • Dermatitis acneiform occurred more frequently in patients aged 12-17 years (77%) compared with patients aged 2-11 years (16%)
  • Non-acneiform rashes occurred more frequently in patients aged 2 to 11 years (53%) compared with patients aged 12 to 17 years (15%)
  • Initiate supportive care at the first sign of dermatologic adverse reaction
  • Hold, dose reduce, or permanently discontinue therapy based on severity
• Embryo-fetal toxicity
  • Can cause fetal harm when administered during pregnancy
  • Advise pregnant patients and females of the reproductive potential of risk to the fetus
  • Effective contraception is recommended during and after therapy in females of reproductive potential and males with female partners of reproductive potential

Pregnancy and Lactation

• Mirdametinib can cause fetal harm or loss of pregnancy when administered to a pregnant woman. Advise pregnant women of the potential risk to a fetus
• Pregnancy testing
  • Verify the pregnancy status of females of reproductive potential before initiating Mirdametinib
• Contraception
  • Females
    • Advise females of reproductive potential to use effective contraception during treatment with mirdametinib and for 6 weeks after the last dose
  • Males
    • Advise male patients with female partners of reproductive potential to use effective contraception during treatment with mirdametinib and for 3 months after the last dose
• Infertility
  • Based on animal findings, mirdametinib may impair fertility in females of reproductive potential 
  • The reversibility of the effects on female fertility in animals is unknown
• Lactation
  • There are no data on the presence of mirdametinib or its metabolites in human milk or their effects on a breastfed child or milk production
  • Because of the potential for adverse reactions in breastfed children, advise women not to breastfeed during treatment with mirdametinib and for 1 week after the last dose