Tazemetostat, as an EZH2 inhibitor, requires special attention to genetic testing, risk management for special populations, and adverse reaction management during medication. At the same time, it is necessary to standardize the dosing regimen and strengthen treatment monitoring. The following is a detailed classification of medication precautions.

1. Genetic testing requirements

(1) EZH2 mutation status must be confirmed through FDA approved testing methods, as the efficacy of wild-type patients is significantly reduced.

(2) Patients with epithelioid sarcoma need to rule out INI1/SMARCB1 gene deletion, which is a prerequisite for medication.

2 Medication Regulations

(1) The standard dose is 800mg orally twice a day, taken on an empty stomach or with meals, but with a fixed administration method.

(2) Tablets should be swallowed whole and should not be crushed or chewed. If missed, they can be supplemented within 4 hours, otherwise the current dose will be skipped.

3 Adverse Reaction Management

(1) Hematological toxicity: Complete blood cell count should be monitored before treatment and every 2 months. Medication should be suspended if there is grade 3 or above anemia or thrombocytopenia.

(2) Secondary malignant tumors: Long term treatment may increase the risk of myelodysplastic syndrome and require regular blood evaluations.

(3) Gastrointestinal reactions: It is recommended to take medication after meals to alleviate nausea, and if necessary, use 5-HT3 receptor antagonists for pre-treatment.

Attention to Special Groups 4

(1) Liver dysfunction: Mild damage (Child Pugh A) should be reduced to 600mgbid, and moderate to severe cases should be avoided.

(2) Renal insufficiency: Mild to moderate without adjustment, severe (eGFR<30) lacking data should be used with caution.

(3) Patients of childbearing age: Dual contraception measures should be taken during treatment and 6 months after discontinuation of medication.

5 Drug Interactions

(1) CYP3A potent inhibitors (such as ketoconazole) can increase blood drug concentrations, and should be reduced by 50% when used in combination.

(2) Proton pump inhibitors may reduce absorption, it is recommended to take them every 2 hours.

6 Treatment Monitoring Requirements

(1) Tumor assessment will be conducted every 8 weeks for 2 years, and later changed to every 12 weeks.

(2) Monitor liver function monthly and suspend medication if transaminase elevation exceeds 3 times ULN.

(3) Regularly evaluate growth and development indicators (when used for pediatric hyperindications).