On 21 December 2018, the FDA approved the CD123-directed cytotoxin tagraxofusp-erzs (Elzonris™, Stemline Therapeutics), for the treatment of adult and paediatric patients of 2 years and older with blastic plasmacytoid dendritic cell neoplasm (BPDCN).

STML-401-0114

The multicentre, multicohort, open-label, single-arm STML-401-0114 study (NCT02113982) enrolled a total of 28 untreated or relapsed/refractory (R/R) BPDCN patients in two cohorts. In the cohort (N=13) with untreated BPDCN patients and at a median follow-up of 11.5 months, 53.8% (7/13) of subjects achieved a (clinical) complete response (CR; 95% CI, 25.1-80.8). The median duration of response was not yet reached. In the cohort including R/R BPDCN patients (N=15), one patient achieved a CR with a duration of 111 days and one patient had a clinical CR lin with a duration of 424 days.

Safety

Common adverse reactions in ≥30% of patients included capillary leak syndrome, nausea, fatigue, peripheral oedema, pyrexia, and weight increase. Common laboratory abnormalities in ≥50% of patients were decreases in albumin, platelets, haemoglobin, calcium, and sodium, as well as increases in glucose, alanine transaminase (ALT) and aspartate transaminase (AST).

Full prescribing information Elzonris™.