Valemetostat, as an EZH2 inhibitor, should be adjusted in dosage according to indications for standard use. Special attention should be paid to liver and kidney function as well as age differences when using it in special populations. The following provides detailed explanations from three aspects: conventional usage, dosage adjustment, and special populations.

1. Conventional usage and dosage

(1) Adult epithelioid sarcoma: Take 200mg orally once a day on an empty stomach (1 hour before or 2 hours after meals).

(2) Follicular lymphoma: The initial dose is the same as 200mg/day, and can be increased to 800mg/day after disease progression.

(3) Medication time: Take at the same time every day, swallow the whole tablet and do not break it.

2. Dose adjustment plan

(1) Liver dysfunction

Child Pugh A grade reduced to 150mg/day, B grade reduced to 100mg/day, and C grade prohibited.

(2) Drug interactions

When using strong CYP3A4 inhibitors in combination, the dosage should be reduced by 50%, and the inducer dosage should be increased by 25%.

3. Medication for special populations

(1) Pregnant women

Effective contraception measures should be taken during the treatment period and 6 months after discontinuation due to clear embryonic toxicity.

(2) Lactating women

Medications may be secreted into breast milk, and breastfeeding is prohibited during the treatment period and within one week after the last administration.

(3) Child patients

Safety and efficacy have not been established for individuals under the age of 18, and its use is not recommended.

(4) Elderly patients

Patients aged 65 and above need to be monitored more frequently as clearance rates may decrease by 30% -40%.

(5) Renal insufficiency

Mild to moderate cases do not require adjustment, and patients with end-stage renal disease should use it with caution (lack of data).

4. Medication precautions

(1) Hematological monitoring: Complete blood cell count is checked before treatment and every 2 weeks, and the incidence of thrombocytopenia is about 15%.

(2) Electrocardiogram monitoring: Risk of QT interval prolongation, correct electrolyte imbalance before medication.

(3) Liver function monitoring: ALT/AST testing is conducted monthly, and if there is a level 3 elevation, medication should be suspended.