Cobimetinib is a targeted therapeutic agent belonging to the MEK inhibitor class. It inhibits tumor cell growth by blocking the activity of key proteins in the MAPK signaling pathway. It is commonly used in combination with a BRAF inhibitor (such as vemurafenib) for the treatment of unresectable or metastatic melanoma with BRAF V600 mutation, which can delay disease progression and improve survival.
Mechanism of Action and Indications
Mechanism of Action: Cobimetinib selectively inhibits MEK1/2 proteins and interferes with signal transduction required for tumor cell proliferation and survival, particularly effective against abnormal activation of the MAPK pathway caused by BRAF mutation.
Indications: Approved for patients with advanced melanoma harboring BRAF V600E or V600K mutation, for use in combination with a BRAF inhibitor.
Dosage Regimen and Precautions
Dosage and AdministrationThe recommended dosage is 60 mg administered orally once daily for 21 consecutive days followed by 7 days off treatment, completing a 28‑day cycle.It must be used in combination with a BRAF inhibitor, and the specific regimen should be strictly followed as prescribed by a physician.
Common Adverse Reactions
Skin reactions: rash, photosensitivity dermatitis (sun protection is required).
Gastrointestinal reactions: diarrhea, nausea (manageable with dietary adjustment or symptomatic medications).
Systemic symptoms: fatigue, pyrexia.
Others: blurred vision (risk of retinal disorders), cardiac toxicity (e.g., decreased left ventricular ejection fraction).
Important Precautions
Confirm BRAF mutation status before initiation; use only in mutation‑positive patients.
Regular monitoring: liver function, electrocardiogram (ECG), creatine phosphokinase (CPK) levels, etc.
Avoid co‑administration with strong CYP3A4 inhibitors or inducers, which may alter drug metabolism.
Contraindicated in pregnant women; effective contraception must be used during treatment.
