Tazemetostat is a selective small-molecule inhibitor of enhancer of zeste homolog 2 (EZH2), a histone methyltransferase involved in epigenetic regulation and cancer-cell proliferation. It is also known by the development codes EPZ-6438 and E-7438.
Tazemetostat is the active moiety of the pharmaceutical drug substance tazemetostat hydrobromide. The free-base active moiety has the molecular formula C34H44N4O4 and molecular weight 572.74 g/mol, while tazemetostat hydrobromide has the formula C34H44N4O4·HBr and molecular weight 653.66 g/mol.
Tazemetostat is an orally active, selective inhibitor of EZH2. It competes with S-adenosylmethionine (SAM) at the EZH2 methyltransferase domain and inhibits methylation of histone H3 at lysine 27 (H3K27).
Tazemetostat Free Base CAS: 1403254-99-8
Tazemetostat Free Base Formula: C34H44N4O4
Tazemetostat Free Base Molecular Weight: 572.74 g/mol
Tazemetostat Hydrobromide CAS: 1467052-75-0
Tazemetostat Hydrobromide Formula: C34H45BrN4O4
Tazemetostat Hydrobromide Molecular Weight: 653.6 g/mol
Development Code: EPZ-6438 / E-7438
The FDA Global Substance Registration System identifies tazemetostat as the active moiety and tazemetostat hydrobromide as the corresponding pharmaceutical salt.
Tazemetostat selectively inhibits EZH2, which is the catalytic component of the Polycomb Repressive Complex 2 (PRC2). EZH2 catalyzes methylation of histone H3 at lysine 27, particularly the trimethylated H3K27me3 mark.
Inhibition of EZH2 reduces H3K27 methylation and alters expression of genes involved in cellular proliferation and differentiation. The pharmacological effect is particularly relevant to tumors in which EZH2 activity or other epigenetic mechanisms contribute to malignant cell growth.
Tazemetostat is an oncology API used in the treatment of selected cancers.
In the United States, Tazverik (tazemetostat) is approved for adults and pediatric patients aged 16 years and older with metastatic or locally advanced epithelioid sarcoma that is not eligible for complete resection. FDA has also approved tazemetostat for selected adult patients with relapsed or refractory follicular lymphoma, including EZH2-mutated disease after at least two prior systemic therapies and patients with no satisfactory alternative treatment options.
Tazemetostat is a synthetic small-molecule API requiring comprehensive chemical and pharmaceutical quality control.
Typical API testing may include:
FDA's chemistry review states that drug-substance and drug-product impurities are controlled using qualified specifications.
Swapnroop Drugs and Pharmaceuticals is an India-based pharmaceutical manufacturing organization supporting pharmaceutical customers with quality-focused API manufacturing and analytical documentation.
Tazemetostat is a specialized oncology API requiring controlled synthesis, impurity profiling, assay determination, residual-solvent control and appropriate pharmaceutical documentation. For commercial API supply, the exact chemical form—free base or hydrobromide—should always be identified on the specification and Certificate of Analysis.
Tazemetostat API should be packed in suitable pharmaceutical-grade containers that protect the material from moisture, contamination and environmental exposure.
Storage conditions, packaging configuration, retest period and transportation requirements should follow validated stability data and the applicable API specification.
For the finished Tazverik tablets, FDA specifies storage below 30°C (86°F) and a 24-month shelf life under the approved conditions. These finished-product conditions should not automatically be used as the drug-substance storage specification.
Documentation for Tazemetostat API may include:
Tazemetostat is a selective EZH2 inhibitor belonging to the targeted oncology API category. The active moiety has the molecular formula C34H44N4O4 and CAS Number 1403254-99-8, while the pharmaceutical hydrobromide salt has CAS Number 1467052-75-0 and molecular weight approximately 653.6 g/mol.
Because the approved pharmaceutical product contains tazemetostat as the hydrobromide salt, API documentation should clearly distinguish between tazemetostat free base and tazemetostat hydrobromide.
Swapnroop Drugs and Pharmaceuticals supports qualified pharmaceutical customers with quality-focused API manufacturing and analytical documentation.
| Parameter | Specification |
|---|---|
| Appearance | white to off-white crystalline powder |
| Identification | IR & HPLC compliant |
| Assay (HPLC) | NLT 98.0% |
| Loss on Drying | NMT 0.5% |
| Residue on Ignition | NMT 0.1% |