Daiichi Sankyo Initiates Pivotal Phase 2 Trial in Japan with Valemetostat in Patients with Adult T-Cell Leukemia-Lymphoma

●　Study to evaluate valemetostat, potential first-in-class EZH1/2 dual inhibitor, in patients with relapsed/refractory ATL in Japan

●　Valemetostat is only dual inhibitor in clinical development for ATL, a rare and aggressive non-Hodgkin’s lymphoma (NHL) with high incidence in Japan

●　Trial initiated based on results from ongoing phase 1 study in several types of NHL

Tokyo - (December 10, 2019) – Daiichi Sankyo Company, Limited (hereafter, Daiichi Sankyo) announced today that the first patient has been dosed in a pivotal phase 2 study in Japan evaluating valemetostat (DS-3201), an investigational EZH1/2 dual inhibitor, in patients with relapsed/refractory adult T-cell leukemia-lymphoma (ATL).

ATL is one of the most aggressive forms of non-Hodgkin’s lymphoma (NHL) and although rare, occurs with greater frequency in certain regions including Japan. Treatments for ATL, a complex and heterogeneous disease, are largely limited to systemic chemotherapy combinations, and patients often face a difficult prognosis, especially for relapsed disease.

“Valemetostat is a novel targeted therapy that has demonstrated preliminary potential in several types of NHL including ATL, which represents one of the greatest areas of need among lymphoma patients, particularly in Japan,” said Kaszushi Araki, DVM, PhD, Valemetostat Global Team Leader, Oncology Clinical Development Department, Oncology Function, Daiichi Sankyo. “Valemetostat is the only EZH1/2 dual inhibitor in clinical development, and our program includes translational research to improve understanding of underlying disease mechanisms and treatment response.”

The pivotal phase 2 trial with valemetostat was initiated based on preliminary findings from an ongoing phase 1 study in patients with several types of NHL, which were presented on December 9th at the 2019 annual meeting of the American Society of Hematology (ASH).[2]