Introduction: Advances and drug development in rare diseases, such as blastic plasmacytoid dendritic cell neoplasm (BPDCN), has historically been limited by small numbers of patients in the target population. In recent years, the development of tagraxofusp (SL-401) (ELZONRIS, Stemline Therapeutics) for the treatment of adult and pediatric BPDCN has been a successful story that led to US FDA approval in December 2018.Areas covered: In this evaluation of tagraxofusp, we briefly review chemistry; pharmacokinetics and pharmacodynamics, as we focus on the clinical experience and future directions.Expert Opinion: Tagraxofusp has been a welcome new addition and a successful initial development step in the targeted treatment of BPDCN. In phase I/II clinical trial, major responses were observed in 90% of treatment-naïve patients, with 72% of the responses observed as complete remissions. Limitations on the usage of tagraxofusp and strategies to handle those limitations were further explored in this review.
Keywords: BPDCN; CD123; ELZONRIS; SL-401; Tagraxofusp; blastic plasmacytoid dendritic cell neoplasm.