BCR ‐ ABL 1 molecular remission after 90 Y ‐epratuzumab tetraxetan radioimmunotherapy in CD 22 + P h + B ‐ ALL : proof of principle

Although targeted therapies are used increasingly in hematologic malignancies, we are unaware of any prior studies of radioimmunotherapy ( RAIT ) in B ‐acute lymphoblastic leukemia ( ALL ), even though this radiosensitive tumor expresses CD 22, potentially a good target for this approach. Here, we report a patient with Philadelphia chromosome‐positive B ‐ ALL in third relapse who received RAIT with 90 yttrium ( 90 Y )‐labeled anti‐ CD 22 epratuzumab tetraxetan. Seven weeks after initiating therapy, the patient achieved a BCR ‐ ABL 1 molecular remission documented by RT ‐q PCR , which is now continuing at 6 months while awaiting an allogeneic hematopoietic stem cell transplant. 90 Y‐Epratuzumab tetraxetan may be a promising therapeutic option for CD 22 + B ‐ ALL patients.