Binimetinib (Mektovi): MEK Inhibitor for BRAF Melanoma
Binimetinib is an oral targeted therapy used to treat advanced melanoma. It belongs to the class of MEK inhibitors (specifically MEK1 and MEK2). The drug works by blocking a critical signaling pathway that drives cell growth in cancers with BRAF mutations.
Binimetinib (Mektovi) is almost exclusively prescribed in combination with encorafenib (Braftovi), a BRAF inhibitor. This dual inhibition targets two different points in the MAPK signaling pathway, resulting in greater antitumor activity and delayed drug resistance compared to using either drug alone.
It is indicated for patients whose cancer has spread or cannot be removed by surgery.
Indications
- Unresectable or Metastatic Melanoma: Treatment of adult patients in combination with encorafenib.
- Biomarker Requirement: Specifically approved for patients with a BRAF V600E or V600K mutation as detected by an FDA-approved test.
- Note: Not indicated for treatment of patients with wild-type BRAF melanoma.
Dosage and administration
Consistency is key. Taken alongside encorafenib.
- Recommended Dose: 45 mg (three 15 mg tablets) taken orally twice daily, approximately 12 hours apart.
- Administration: Swallow tablets whole with water. Can be taken with or without food.
- Missed Dose: If a dose is missed by more than 6 hours, skip it and take the next dose at the regular time.
- Eye Conditions: History of Retinal Vein Occlusion (RVO).
- Pregnancy and Breastfeeding: Can cause fetal harm. Effective contraception is required.
- Hypersensitivity to binimetinib.
Specific monitoring for ocular and cardiac/muscular issues is mandatory.
- Ocular Events: Serous retinopathy (fluid accumulation in the eye) causing blurred vision or light flashes. Regular eye exams are recommended.
- Cardiac Failure: Decrease in Left Ventricular Ejection Fraction (LVEF). ECHO scans are required before and during treatment.
- Rhabdomyolysis: Elevation of Creatine Phosphokinase (CPK) levels indicating muscle stress.
- General: Rash, diarrhea, nausea, peripheral edema (swelling).
