valemetostat valemetostat valemetostat (trade name ezharmia) is a drug used for the treatment of adult t-cell leukemia/lymphoma (atl). valemetostatclinical datatrade namesezharmiaother namesvalemetostat tosilate (jan); ds-3201; ds-3201bidentifiers iupac name (2r)-7-chloro-2--n--2,4-dimethyl-1,3-benzodioxole-5-carboxamide cas number1809336-39-7 1809336-93-3 (tosylate)pubchem cid126481870unii60rd0234vekeggd11662chemical and physical dataformulac26h34cln3o4molar mass488.03 g·mol−1 valemetostat is an inhibitor of the enzymes enhancer of zeste homolog 1 (ezh1) and enhancer of zeste homolog 2 (ezh2), which are implicated in the etiology of some forms of cancer including non-hodgkin lymphomas. in japan, valemetostat was approved in september 2022 for patients with relapsed or refractory adult t-cell leukemia/lymphoma.