Tagraxofusp-erzs™ (Elzonris) infusion was granted US Food and Drug Administration (FDA) approval for the treatment of blastic plasmacytoid dendritic cell neoplasm (BPDCN), according to news releases from the US FDA and Stemline Therapeutics, the developer of tagraxofusp. It is approved for both treatment-naïve and relapsed/refractory BPDCN in adults and pediatric patients ages 2 years and older.1,2
BPDCN is a rare, aggressive hematologic cancer that affects the bone marrow and blood. Diagnosis is based on the immunophenotypic diagnostic triad of CD123, CD4, and CD56. Symptoms typically manifest in the bone marrow and/or skin, but may manifest in the lymph nodes and other organs as well. Patients often present with signs and symptoms of leukemia or the disease evolves into acute leukemia. BPDCN is more common in men and in those aged 60 and older. Outcomes are historically poor.
“Prior to [this] 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, MD, 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. Oftentimes, patients are unable to tolerate the intensive therapy; therefore, alternative options are urgently needed, Dr Pazdur stated in the news release.1
Tagraxofusp is a CD123-directed cytotoxin indicated for the treatment of BPDCN in adult and pediatric patients aged 2 years and older. This is the first drug approved to treat BPDCN, the standard-of-care treatment for which is intensive chemotherapy followed by bone marrow transplantation. However, most patients cannot tolerate this therapy.
The researchers presented clinical data from Study STML-401-0114 (ClinicalTrials.gov Identifier, NCT02113982) at the 2018 American Society of Hematology Annual Meeting & Exposition. Of 29 treatment-naïve patients treated with tagraxofusp 12 µg/kg/day, 21 patients (72%) achieved complete remission (CR)/CR with a skin abnormality not indicative of active disease (CRc), with median duration of CR/CRc not reached (range, 1.3 to 32.2 months). Overall response rate was 90% (26 patients; 95% CI, 72.6, 97.8), and 13 patients (45%) were bridged to stem cell transplant, following remission.