Valemetostat Tosilate: First Approval

Declarations Funding The preparation of this review was not supported by any external funding. Authorship and Conflict of interest During the peer review process the manufacturer of the agent under review was offered an opportunity to comment on the article. Changes resulting from any comments received were made by the authors on the basis of scientific completeness and accuracy. Susan J. Keam is a contracted employee of Adis International Ltd/Springer Nature, and declares no relevant conflicts of interest. All authors contributed to the review and are responsible for the article content. Ethics approval, Consent to participate, Consent to publish, Availability of data and material, Code availability not applicable Additional information about this Adis Drug Review can be found here. Abstract Valemetostat tosilate (valemetostat; EZHARMIA®), a selective dual inhibitor of histone-lysine N-methyltransferases enhancer of zeste homolog 1 and 2 (EZH1/2), is being developed by Daiichi Sankyo Company, Ltd for the treatment of various haematological malignancies and solid tumours, including types of non-Hodgkin lymphomas (NHL). Valemetostat was approved in Japan in September 2022 for the treatment of patients with relapsed or refractory adult T-cell leukaemia/lymphoma (R/R ATL), a subtype of NHL. This article summarizes the milestones in the development of valemetostat leading to this first approval for R/R ATL. © Springer Nature Switzerland AG 2022