Tazverik (tazemetostat hydrobromide)

Advertisement

Last reviewed · Source: First Databank (FDB) drug data

Overview

Tazemetostat hydrobromide, a potent and selective inhibitor of the histone methyltransferase enhancer of zeste homolog 2 (EZH2), is an antineoplastic agent.

Tazemetostat hydrobromide, a potent and selective inhibitor of the histone methyltransferase enhancer of zeste homolog 2 (EZH2), including EZH2 with Y646X, A682G, or A692V activating mutations, is an antineoplastic agent. EZH2 is the catalytic subunit of the polycomb repressive complex 2 (PRC2), a complex that methylates lysine 27 of histone H3 to promote transcriptional silencing of target genes. In vitro and in vivo, loss or dysfunction of the chromatin remodeling complex switch/sucrose nonfermentable (SWI/SNF) results in aberrant EZH2 activity and oncogenic dependency on EZH2 enzymatic activity.

In vivo, tazemetostat has demonstrated antitumor activity in xenograft models of B-cell lymphoma with or without EZH2 activating mutations; however, the drug has demonstrated greater effects on inhibition of proliferation of lymphoma cell lines with mutant EZH2. Tazemetostat also has demonstrated inhibition of EZH1 with a half-maximal inhibitory concentration approximately 36 times higher than the half-maximal inhibitory concentration for EZH2.

The mean absolute bioavailability of tazemetostat following oral administration is approximately 33%. Following oral administration, peak plasma concentrations of tazemetostat are achieved in approximately 1-2 hours. Following administration of tazemetostat, systemic exposure to tazemetostat increases in an approximately dose-proportional manner over a dosage range of 200-1600 mg twice daily.

Following repeated twice-daily dosing, steady-state concentrations of the drug are attained in 15 days, with a mean accumulation ratio of 0.58. Administration of a high-fat, high-calorie meal (approximately 800-1000 calories) with tazemetostat did not affect systemic exposure to the drug. Tazemetostat is 88% bound to plasma proteins in vitro.

Tazemetostat is metabolized principally by cytochrome P-450 (CYP) isoenzyme 3A to form the major inactive metabolites M5 and M3. M5 is further metabolized by CYP3A. Most (94%) of an orally administered dose is recovered over 12 days; 79% of the dose is eliminated in feces and 15% is eliminated in urine.

The elimination half-life of tazemetostat is 3.1 hours. The pharmacokinetics of tazemetostat are not affected by age (16-91 years of age), sex, body weight (37-173 kg), or race.

USES: This medication is used to treat certain types of cancer (epithelioid sarcoma or follicular lymphoma). It works by slowing or stopping the growth of cancer cells. This drug has been withdrawn from the US market due to problems with safety.

Generic name: tazemetostat hydrobromide
Pronunciation: (TAZ-e-MET-oh-stat)

Reference product & biosimilars

No reference, biosimilar or interchangeable associated with this drug.

Today’s intelligence on Tazverik

Intelligence content is not available yet.

Indications

The following indications are listed for Tazverik:

  • Epithelioid Sarcoma
  • Follicular Lymphoma
  • Follicular Lymphoma With Ezh2 Mutation

Also known as: Ezh2 Mutant Follicular Lymphoma, Follicular B-Cell Lymphoma, Follicular B-Cell Non-Hodgkin's Lymphoma.

Dosing

Dosage of tazemetostat hydrobromide is expressed in terms of tazemetostat.

If adverse reactions occur during tazemetostat therapy, temporary interruption of therapy, dosage reduction, and/or discontinuance of the drug may be necessary. If dosage reduction is required, the dosage of tazemetostat should be reduced as described in Table 1.

Table 1: Recommended Dosage Reduction for Tazemetostat Toxicity

Dose Reduction Level Dosage Reduction after Recovery from Toxicity (Initial Dosage = 800 mg twice daily) First Resume at 600 mg twice daily Second Resume at 400 mg twice daily Third Permanently discontinue drug

The following Recommended Dosage Modification for Tazemetostat Toxicity table indicates the recommended dosage modification (i.e., temporary interruption of therapy, dosage reduction, discontinuance of therapy) for adverse effects according to severity.

Table 2. Recommended Dosage Modification for Tazemetostat Toxicity

Adverse Reaction and Toxicity Occurrence Dosage Modification Severity Neutropenia Absolute neutrophil First Withhold therapy; when count (ANC) <1000/mm3 ANC improves to baseline or >=1000/mm3, resume therapy at same dosage Second or third Withhold therapy; when ANC improves to baseline or >=1000/mm3, resume therapy at a reduced dosage Fourth Permanently discontinue therapy Thrombocytopenia Platelet count First or second Withhold therapy; when <50,000/mm3 platelet count improves to baseline or >=75,000/mm3, resume therapy at a reduced dosage Third Permanently discontinue therapy Anemia Hemoglobin concentration Any Withhold therapy; when <8 g/dL anemia improves to grade 1 or less or to baseline, resume therapy at same or reduced dosage Other Toxicity Grade 3 First or second Withhold therapy; when toxicity improves to grade 1 or less or to baseline, resume therapy at a reduced dosage Third Permanently discontinue therapy Grade 4 First Withhold therapy; when toxicity improves to grade 1 or less or to baseline, resume therapy at a reduced dosage Second Permanently discontinue therapy

Drug interactions

Tazemetostat is metabolized principally by cytochrome P-450 (CYP) isoenzyme 3A.

In vitro, tazemetostat does not inhibit CYP isoenzymes 1A2, 2B6, 2C9, or 2D6 at clinically relevant concentrations.

In vitro studies also suggest that tazemetostat is a substrate of P-glycoprotein (P-gp), but is not a substrate of breast cancer resistance protein (BCRP), organic cation transporter (OCT) 2, organic anion transporter (OAT) 3, multidrug and toxin extrusion (MATE) transporter 1, organic anion transporting polypeptide (OATP) 1B1, and OATP1B3.

In vitro, tazemetostat inhibits MATE1 and MATE2K, but does not inhibit P-gp, BCRP, OATP1B1, OATP1B3, OCT1, OCT2, OAT1, OAT3, or bile salt export pump (BSEP) at clinically relevant concentrations.

Contraindications

*None.

Adverse reactions

Adverse effects reported in 20% or more of patients receiving tazemetostat for the treatment of epithelioid sarcoma include pain, fatigue, nausea, decreased appetite, vomiting, and constipation. Grade 3 or 4 laboratory abnormalities reported in 10% or more of patients receiving tazemetostat include anemia and lymphocytopenia.

Adverse effects reported in 20% or more of patients receiving tazemetostat for the treatment of follicular lymphoma include fatigue, upper respiratory tract infection, musculoskeletal pain, nausea, and abdominal pain. Grade 3 or 4 laboratory abnormalities reported in 5% or more of patients receiving tazemetostat include lymphocytopenia, hyperglycemia, leukopenia, neutropenia, thrombocytopenia, and anemia.

Precautions

No enhanced messaging available.

ICD codes

No ICD codes are available for this drug.

Formulary status

Search health-plan coverage for this drug by ZIP code.

Enter a ZIP code to view available health plans.

Last reviewed · Source: First Databank (FDB) drug data