Precautions of Tazemetostat

1 Secondary Malignancies

The risk of developing secondary malignancies is increased following treatment with Tazemetostat. Across clinical trials of 758 adults who received Tazemetostat 800 mg twice daily as monotherapy, myelodysplastic syndrome (MDS), acute myeloid leukemia (AML), or B-cell acute lymphoblastic leukemia (B-ALL) occurred in 1.7% of patients. One pediatric patient developed T-cell lymphoblastic lymphoma (T-LBL). Monitor patients  long-term for the development of secondary malignancies.

2 Embryo-Fetal Toxicity

Based on findings from animal studies and its mechanism of action, Tazemetostat can cause fetal harm when administered to pregnant women. There are no available data on Tazemetostat use in pregnant women to inform  the drug-associated risk. Administration of tazemetostat to pregnant rats and rabbits during organogenesis resulted in dose-dependent increases in skeletal developmental abnormalities in both species beginning at  maternal exposures approximately 1.5 times the adult human exposure (area under the plasma concentration time curve [AUC0-45h]) at the 800 mg twice daily dose.

Advise pregnant women of the potential risk to a fetus. Advise females of reproductive potential to use effective  contraception during treatment with Tazemetostat and for 6 months after the final dose. Advise males with  female partners of reproductive potential to use effective contraception during treatment with Tazemetostat and  for 3 months after the final dose.

from FDA，2024.08