The FDA has issued a warning that taking Tazverik (tazemetostat) increases the risk of hematologic second primary malignancies (SPMs) and has determined that the risks of the medication outweigh the benefits.
Tazverik is an oral medication that received accelerated approval for metastatic, locally-advanced epithelioid sarcoma and for relapsed or refractory follicular lymphoma in 2020. At this time, there was an incidence rate of SPMs of 1.7%. However, data released in the stage 3 Symphony 1 trial in March of this year found that SPMs had developed in 5.7% of patients taking the medication and in none of the controls. The finding led Ipsen to voluntarily withdraw the medication from the market the same month.
Most SPMs developed after one to three years of taking Tazverik, although the earliest case was after 7.5 months. The majority were myelodysplastic syndrome (MDS) and acute myeloid leukemia, but others included B-cell acute lymphoblastic leukemia and clonal cytopenia of undetermined significance. Of the 18 patients with SPMs, three died and 14 had no resolution.