Dosing and Administration Guide for Tazemetostat

The specific treatment regimen for tazemetostat should be determined by a qualified physician based on the patient's condition, body weight, liver and kidney function, concomitant medications, and other relevant factors. Do not adjust the dosage on your own.

Usual Dose for Follicular Lymphoma in Adults

Dose: Oral administration, 800 mg twice daily.

Duration: Until disease progression or unacceptable toxicity.

Note: Selection of patients with relapsed or refractory (R/R) follicular lymphoma (FL) based on EZH2 mutation status.

Indication: For the treatment of adult patients with relapsed or refractory follicular lymphoma whose tumors harbor EZH2 mutations and who have received at least two prior systemic therapies or have no satisfactory alternative treatment options.

Usual Dose for Soft Tissue Sarcoma in Pediatric Patients

Age: 16 years and older.

Dose: Oral administration, 800 mg twice daily.

Duration: Until disease progression or unacceptable toxicity.

Indication: For the treatment of pediatric patients aged 16 years and older with metastatic or locally advanced epithelioid sarcoma who are not candidates for complete resection.

Dosage Adjustment for Renal Impairment

Mild, moderate, severe, or end-stage renal impairment: Dose adjustment is not recommended.

Dosage Adjustment for Hepatic Impairment

Mild hepatic impairment (total bilirubin >1 to 1.5 times the upper limit of normal [ULN] or AST > ULN): Dose adjustment is not recommended.

Moderate hepatic impairment (total bilirubin >1.5 to 3 times ULN) or severe hepatic impairment (total bilirubin >3 times ULN): Data not available.

Dosage Adjustment for Adverse Reactions

First dose reduction: Oral administration, 600 mg twice daily.

Second dose reduction: Oral administration, 400 mg twice daily.

Permanently discontinue tazemetostat if the patient cannot tolerate the dose of 400 mg twice daily.

Neutropenia

When neutrophil count is <1 × 10⁹/L: Withhold treatment until neutrophil count recovers to ≥1 × 10⁹/L or baseline.

First occurrence: Resume at the same dose.

Second or third occurrence: Reduce the dose upon treatment resumption.

Fourth occurrence: Permanently discontinue tazemetostat.

Thrombocytopenia

When platelet count is <50 × 10⁹/L: Withhold treatment until platelet count recovers to ≥75 × 10⁹/L or baseline.

First or second occurrence: Reduce the dose upon treatment resumption.

Third occurrence: Permanently discontinue tazemetostat.

Anemia

When hemoglobin is <8 g/dL: Withhold treatment until improvement to at least Grade 1 or baseline, then resume at the same or a reduced dose.

Other Adverse Reactions

Grade 3 adverse reactions: Withhold treatment until improvement to at least Grade 1 or baseline.

First or second occurrence: Reduce the dose upon treatment resumption.

Third occurrence: Permanently discontinue tazemetostat.

Grade 4 adverse reactions: Withhold treatment until improvement to at least Grade 1 or baseline.

First occurrence: Reduce the dose upon treatment resumption.

Second occurrence: Permanently discontinue tazemetostat.

Dosage Adjustment for Drug Interactions

Concomitant use with moderate or strong CYP3A inhibitors: 

Avoid concomitant use of tazemetostat with moderate or strong CYP3A inhibitors.

If concomitant use with a moderate CYP3A inhibitor is unavoidable, reduce the dose of tazemetostat.

After discontinuation of the moderate CYP3A inhibitor and three elimination half-lives, resume the tazemetostat dose used before concomitant administration.

Recommended Dose Adjustments When Used with Moderate CYP3A Inhibitors

If the current dose is 800 mg twice daily: Reduce to 400 mg twice daily.

If the current dose is 600 mg twice daily: Reduce to 400 mg for the first dose and 200 mg for the second dose (oral administration).

If the current dose is 400 mg twice daily: Reduce to 200 mg twice daily.