Targeting CD123 in blastic plasmacytoid dendritic cell neoplasm using allogeneic anti-CD123 CAR T cells

Area of Science:

• Hematologic Malignancies
• Immunotherapy
• Cellular Therapy

Background:

• Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare cancer with poor prognosis.
• CD123 (interleukin 3 receptor subunit alpha) is highly expressed on BPDCN cells, making it a key therapeutic target.

Purpose of the Study:

• To evaluate the preclinical antitumor activity of UCART123, an allogeneic anti-CD123 chimeric antigen receptor (CAR) T-cell therapy, against BPDCN.

Main Methods:

• In vitro cytotoxicity and T-cell degranulation assays using CD123-positive BPDCN samples.
• Assessment of UCART123 efficacy in patient-derived BPDCN xenograft mouse models.
• Analysis of CD123 antigen loss as a resistance mechanism.

Main Results:

• UCART123 demonstrated selective killing of BPDCN cells, sparing normal hematopoietic progenitor cells.
• UCART123 induced increased IFNγ secretion upon encountering BPDCN cells.
• UCART123 achieved BPDCN eradication and long-term disease-free survival in a subset of xenograft models.
• CD123 antigen loss was observed in one of three BPDCN patient-derived xenografts.

Conclusions:

• Allogeneic UCART123 cells exhibit significant preclinical anti-BPDCN activity.
• UCART123 represents a potential therapeutic strategy for BPDCN.
• Further investigation is warranted to address antigen escape mechanisms in CD123-targeted therapies.