Tazemetostat (EPZ-6438) Tazemetostat (EPZ-6438, E7438) is a potent, and selective EZH2 inhibitor with K i and IC50 of 2.5 nM and 11 nM in cell-free assays, exhibiting a 35-fold selectivity versus EZH1 and >4,500-fold selectivity relative to 14 other HMT In vitro
EPZ-6438 concentration-dependently reduces global H3K27Me3 levels in wild-type or SMARCB1 mutant cells, and induces strong antiproliferative effects with IC50 ranging from 32 nM to 1000 nM in SMARCB1-deleted MRT cell lines. EPZ-6438 induces gene expression of neuronal differentiation and cell cycle inhibition, while inhibtis expression of Hedgehog pathway genes, MYC and EZH2. The antiproliferative effect of EPZ-6438 is enhanced by either prednisolone or dexamethasone in several EZH2 mutant lymphoma cell lines.
In vivo
In SCID mice bearing s.c. G401 xenografts, EPZ-6438 induces tumor stasis during the administration period and produces a significant tumor growth delay with minimal effect on body weight. Cell Data
