Dual CD19 and CD123 targeting prevents antigen-loss relapses after CD19-directed immunotherapies

Potent CD19-directed immunotherapies, such as chimeric antigen receptor T cells (CART) and blinatumomab, have drastically changed the outcome of patients with relapsed/refractory B cell acute lymphoblastic leukemia (B-ALL). However, CD19-negative relapses have emerged as a major problem that is observed in approximately 30% of treated patients. Developing approaches to preventing and treating antigen-loss escapes would therefore represent a vertical advance in the field. Here, we found that in primary patient samples, the IL-3 receptor α chain CD123 was highly expressed on leukemia-initiating cells and CD19-negative blasts in bulk B-ALL at baseline and at relapse after CART19 administration. Using intravital…

• AA
  American Association for Cancer Research
• BS
  Bristol-Myers Squibb
• SB
  St. Baldrick's Foundation
• UO
  University of Pennsylvania
• SJ
  St. Jude Children's Research Hospital
• SF
  Society for Immunotherapy of Cancer
• NI
  National Institutes of Health

  Awards: 5R01CA120409, CA016520
• SU
  Stand Up To Cancer