The Menarini Group ("Menarini"), a leading international pharmaceutical and diagnostics company, and Stemline Therapeutics, Inc. ("Stemline"), a wholly-owned subsidiary of the Menarini Group, today announced that Nippon Shinyaku Co., Ltd. (Nippon Shinyaku), Stemline's development partner in Japan, received Orphan Drug Designation for tagraxofusp, from the Japanese Ministry of Health, Labor and Welfare (MHLW) for the expected indication of blastic plasmacytoid dendritic cell neoplasm (BPDCN).

BPDCN is an aggressive orphan hematologic malignancy with historically poor clinical outcomes. Stemline's ELZONRIS® (tagraxofusp) is the only approved treatment for patients with BPDCN, and the first and only approved CD123-targeted therapy, in both the United States and Europe.

Orphan drugs are designated by Japan's MHLW for treatments that are intended for use in fewer than 50,000 patients, where there is also a particularly high medical need. Orphan drug designation can potentially shorten the period required to obtain regulatory approval in Japan by several months, thereby enabling faster patient access.

In Japan, tagraxofusp is being developed by Nippon Shinyaku, which is currently conducting a Phase 1/2 clinical trial. In March 2021, Stemline and Nippon Shinyaku entered into an exclusive licensing agreement for the development and commercialization of tagraxofusp in Japan, including the possibility of co-promotion.

"The MHLW's decision to grant Orphan Drug Designation recognizes the potential positive impact tagraxofusp could have on BPDCN patients in Japan, a patient population that currently has limited treatment options," said Elcin Barker Ergun, CEO of the Menarini Group.  "This achievement by our partner, Nippon Shinyaku, advances our commitment to bring transformative new therapeutic options to patients with difficult-to-treat cancers, and to deliver innovative medicines to people around the globe."