Ministry Of Health, Labour and Welfare Grants Orphan Drug Designation in Japan to Anticancer Agent Tazemetostat for Unresectable INI1-Negative Epithelioid Sarcoma
TOKYO, August 29, 2025 – (JCN Newswire via SeaPRwire.com) – Eisai Co., Ltd. (Headquarters: Tokyo, CEO: Haruo Naito, “Eisai”) announced today that it has received orphan drug designation for anticancer agent the EZH2*1 inhibitor tazemetostat hydrobromide (generic name, product name “Tazverik® Tablets 200 mg”, “tazemetostat”) for unresectable INI1*2-negative epithelioid sarcoma that has progressed after chemotherapy, from the Ministry of Health, Labour and Welfare (MHLW).Epithelioid sarcoma is a type of soft tissue sarcoma that is a rare cancer estimated to account for about 1% of all soft tissue sarcoma.1 Only 174 cases were registered from major hospitals across Japan over a10-year period from 2006 to 2015.2 Loss of INI1, which is a negative regulator of EZH2, is observed in over 90% of epithelioid sarcoma cases,3 leading to EZH2 activation that is believed to drive tumor onset and malignant progression. Treatment options are limited, resulting in an extremely high unmet medical need.Tazemetostat was approved…