FDA Approves Tagraxofusp-erzs for Blastic Plasmacytoid Dendritic Cell Neoplasm

CD123-directed cytotoxin is indicated in adults and in paediatric patients

On 21 December 2018, the US Food and Drug Administration (FDA) approved tagraxofusp-erzs(ELZONRIS™, Stemline Therapeutics), a CD123-directed cytotoxin, for blastic plasmacytoid dendritic cell neoplasm (BPDCN) in adults and in paediatric patients 2 years and older.

Approval was based on a multicentre, multicohort, open-label, single-arm clinical trial (STML-401-0114; NCT 02113982) in patients with untreated or relapsed/refractory BPDCN. Patients received tagraxofusp-erzs at the recommended dose of 12 mcg/kg (see schedule below). In the pivotal cohort, seven (53.8%; 95% CI: 25.1, 80.8) of 13 patients with untreated BPDCN achieved complete response/clinical complete response after a median follow-up of 11.5 months. The median response duration was not reached. In the second cohort, of 15 patients with relapsed or refractory BPDCN, one patient achieved a complete response (duration 111 days) and one patient achieved a clinical complete response (duration 424 days). 

Most common adverse reactions (incidence ≥ 30%) are capillary leak syndrome, nausea, fatigue, peripheral oedema, pyrexia, and weight increase. Most common laboratory abnormalities (incidence ≥ 50%) are decreases in albumin, platelets, haemoglobin, calcium, and sodium, and increases in glucose, ALT and AST. 

The recommended tagraxofusp-erzs dose and schedule is 12 mcg/kg administered intravenously over 15 minutes once daily on days 1 to 5 of a 21-day cycle. 

Full prescribing information for ELZONRIS is available here

FDA granted this application priority review and breakthrough therapy designation. This therapy also received orphan drug designation. 

Healthcare professionals should report all serious adverse events suspected to be associated with the use of any medicine and device to FDA’s MedWatch Reporting System.