Dosage of Cobimetinib

1. Patient Selection for Melanoma Treatment

Before initiating the combined treatment of cobimetinib and vemurafenib, confirm the presence of BRAF V600E or V600K mutations in the tumor specimen.

2. Recommended Dosage

The recommended administration regimen for cobimetinib is 60 mg (three 20 mg tablets) per dose, taken orally once daily, for the first 21 days of each 28-day cycle, until disease progression or unacceptable toxicity occurs.

Cobimetinib can be taken with food or on an empty stomach.

If a dose of cobimetinib is missed or vomiting occurs after administration, resume dosing at the next scheduled time.

3. Dosage Adjustment

Concurrent Use with CYP3A Inhibitors

Do not use strong or moderate CYP3A inhibitors concurrently during cobimetinib administration.

If concurrent use of a moderate CYP3A inhibitor is unavoidable for a short period (14 days or less) in patients taking 60 mg of cobimetinib, reduce the cobimetinib dose to 20 mg. After discontinuing the moderate CYP3A inhibitor, resume the previous cobimetinib dose of 60 mg.

For patients taking a reduced dose of cobimetinib (40 mg or 20 mg daily), use alternative medications to strong or moderate CYP3A inhibitors.

FDA，2023.05