Evaluating tagraxofusp for the treatment of blastic plasmacytoid dendritic cell neoplasm (BPDCN)

Unique among hematologic malignancies, blastic plasmacytoid dendritic cell neoplasm (BPDCN) affects multiple compartments including bone marrow, hematologic, lymphatic, dermatologic, and central nervous systems (CNS). Treating BPDCN is challenging, historically, as patients display refractoriness to chemotherapy and absence of long-term remissions in many cases not treated with hematopoietic stem cell transplantation. Discovering the prevalent overexpression of surface receptor CD123 (IL3-Rα) on BPDCN cells led to development of tagraxofusp, a novel anti-CD123 agent for patients with BPDCN.

Herein, the authors discuss the preclinical development and phase I/II clinical studies, which led to the approval of tagraxofusp. They discuss the current treatment landscape of BPDCN with tagraxofusp alone or combined with chemotherapy and highlight several ongoing clinical trials involving combinations of tagraxofusp with novel targeted therapeutics for BPDCN.

Tagraxofusp has significantly improved the treatment landscape for patients with newly diagnosed BPDCN and has led to investigative efforts and augmentation of various strategies of targeting CD123, such as antibody-drug conjugates and anti-CD123 chimeric antigen receptor T-cells. However, relapsed/refractory disease and CNS-involvement of BPDCN remain therapeutic challenges. The authors recommend that healthcare providers consider multiple-agent clinical trial approaches and adequate CNS-prophylaxis for all patients with BPDCN.