FDA Approves Stemline Therapeutics BPDCN Therapy Elzonris

Rare Daily Staff

The U.S. Food and Drug Administration Stemline Therapeutics Elzonris infusion for the treatment of blastic plasmacytoid dendritic cell neoplasm (BPDCN), an aggressive and rare cancer.

BPDCN is an aggressive and rare disease of the bone marrow and blood that can affect multiple organs, including the lymph nodes and the skin. It often presents as leukemia or evolves into acute leukemia. The disease is more common in men than women and in patients 60 years and older.

Elzonris, which was approved for adults and pediatric patients at least two years of age, is the first approved therapy for BPDCN. It is a targeted therapy directed to the interleukin-3 (IL-3) receptor-α (CD123), a target present on a wide range of malignancies.

The labeling for Elzonris includes a Boxed Warning to alert health care professionals and patients about the increased risk of capillary leak syndrome that may be life-threatening or fatal to patients in treatment.

“Prior to today’s approval, there had been no FDA approved therapies for BPDCN. The standard of care has been intensive chemotherapy followed by bone marrow transplantation,” said Richard Pazdur, director of the FDA’s Oncology Center of Excellence and acting director of the Office of Hematology and Oncology Products in the FDA’s Center for Drug Evaluation and Research. “Many patients with BPDCN are unable to tolerate this intensive therapy, so there is an urgent need for alternative treatment options.”

The efficacy of Elzonris was studied in two cohorts of patients in a single-arm clinical trial. The first trial cohort enrolled 13 patients with untreated BPDCN, and seven patients (54 percent) achieved complete remission, or complete remission with a skin abnormality not indicative of active disease. The second cohort included 15 patients with relapsed or refractory BPDCN. One patient achieved complete remission and one achieved complete remission with a skin abnormality not indicative of active disease.

The labeling for Elzonris contains a Boxed Warning to alert health care professionals and patients about the increased risk of capillary leak syndrome which may be life-threatening or fatal to patients in treatment.

The FDA granted this application Breakthrough Therapy and Priority Review designation. Elzonris also received Orphan Drug designation, which provides incentives to assist and encourage the development of drugs for rare diseases. The European Medicines Agency has granted Elzonris accelerated assessment for its upcoming Marketing Authorization Application submission, which is expected in the first quarter of 2019.

December 21, 2018