Lenvatinib is a multi-target tyrosine kinase inhibitor primarily used for the treatment of malignant tumors such as thyroid cancer, renal cell carcinoma, and hepatocellular carcinoma. Its mechanism of action includes inhibiting signaling pathways such as vascular endothelial growth factor receptor (VEGFR) and fibroblast growth factor receptor (FGFR), thereby blocking tumor angiogenesis and tumor cell proliferation.

1、 Usage and dosage

1. Thyroid cancer

The recommended dosage for adults is 24mg per day, taken orally once. Continue treatment until disease progression or unacceptable toxicity occurs.

2. Renal cell carcinoma

When used in combination with everolimus, the recommended dosage is 18mg lenvatinib and 5mg everolimus per day, both taken orally once. Continue treatment until disease progression or unacceptable toxicity occurs.

3. Hepatocellular carcinoma

Patients weighing ≥ 60kg: 12mg per day; patients weighing<60kg: 8mg per day, both taken orally once. Continue treatment until disease progression or unacceptable toxicity occurs.

2、 Drug resistance mechanism

1. Target mutation

Tumor cells may experience a decrease in drug binding ability through mutations in target genes such as VEGFR and FGFR.

2. Bypass activation

Tumors may activate other pro angiogenic signaling pathways, such as PDGFR, MET, etc., bypassing drug inhibition.

3. Drug efflux

Tumor cells may overexpress drug efflux pump proteins such as P-gp, reducing intracellular drug concentration.

3、 Precautions

1. Hypertension

During treatment, hypertension is common and requires regular monitoring of blood pressure. Grade 3 hypertension should be temporarily suspended from medication, and after control, the dosage should be reduced and restored; Level 4 requires permanent discontinuation of medication.

2. Cardiac toxicity

May cause QT interval prolongation and cardiac dysfunction. Electrocardiogram and cardiac function should be monitored before and during treatment.

3. Risk of bleeding

May increase bleeding tendency, severe bleeding events require immediate discontinuation of medication.

4. Abnormal liver function

Regular monitoring of liver function is required. Grade 3 or 4 liver toxicity should be temporarily suspended from medication, reduced or permanently discontinued after recovery.

5. Proteinuria

Renal syndrome grade proteinuria may occur, and regular urine tests are required. Grade 2 and above proteinuria should be reduced or medication should be suspended.