EMA grants orphan drug status to Stemline’s SL-401 for AML treatment

SL-401 is a targeted therapy directed to the interleukin-3 receptor (IL-3R) present on cancer stem cells (CSCs) and tumor bulk of BPDCN, AML, and other hematologic cancers.

It is currently being investigated in three clinical trials across seven indications.

The clinical programs include an ongoing pivotal trial in BPDCN, and studies in early and late stage AML and various high-risk myeloproliferative neoplasms.

The benefits of the orphan drug status include a 10-year period of market exclusivity in the EU, if approved.

Stemline Therapeutics chief medical officer and head of research and development Eric Rowinsky said: "We are pleased with the EMA’s decision to grant Orphan Drug designation to SL-401 as it underscores the continued unmet need in AML.

"Additionally, SL-401’s orphan designation from regulators in both the U.S. and Europe provides Stemline with several potential avenues to accelerate clinical development in AML and other orphan indications."

Stemline is enrolling patients in the expansion stage of the SL-401 pivotal trialin relapsed/refractoryblastic plasmacytoid dendritic cell neoplasm (BPDCN).

It follows the completion of the lead-in stage of the trial that enrolled first-line and relapsed/refractory BPDCN and relapsed/refractory acute myeloid leukemia (AML) patients at escalating doses, confirming the dose and schedule for the current expansion stage.

An earlier Phase 1/2 trial with SL-401 showed major responses, including complete responses, in both first-line and relapsed/refractory BPDCN as well as relapsed/refractory AML.