Clinical Factors Associated with Prolonged Cytopenias after CD19 Chimeric Antigen Receptor T-Cell Therapy for Pediatric B-Cell Acute Lymphoblastic Leukemia

• Published in: Blood 2024-11, Vol.144, p.4827-4827
• Main Authors: Myers, Regina M., Li, Yimei, Lamble, Adam, Hsieh, Emily M., John, Samuel, Dolan, Gregory, Liu, Hongyan, Chen, Lee, Sheppard, Jennifer, DiNofia, Amanda M., Annesley, Colleen, Grupp, Stephan A., Bhojwani, Deepa, Gardner, Rebecca A., Gore, Lia, Rheingold, Susan R, Shah, Nirali N., Pulsipher, Michael A.
• Format: Article
• Language: English
• ISSN: 0006-4971
• DOI: 10.1182/blood-2024-202027

Introduction: Cytopenias are among the most common CD19 CAR T cell therapy (CAR19)-related adverse events. Although the frequency, severity, risk factors and outcomes of CAR19 related cytopenias are well described in adult lymphoma and multiple myeloma, data for pediatric B-lymphoblastic leukemia (B-ALL) is limited. As a bone marrow infiltrative disease, cytopenia characteristics in B-ALL differ from lymphoma, making this an especially relevant data gap to address. Methods: We conducted a multicenter, retrospective review of children and young adults treated with 4-1BB-based CAR19 constructs for B-ALL between 2012-2022 at 6 US centers in the CAR-Multicenter Analysis cohort. The cytopenia analysis was limited to patients in a complete remission (CR) at Day 28 (D28) after infusion. Later timepoints were further limited to those who remained in remission without hematopoietic cell transplant (HCT) or alternative therapy. The primary outcome was a composite endpoint of at least 1 severe cytopenia (grade [gr] 3-4 neutropenia, anemia or thrombocytopenia) present at D28 after infusion per CTCAE v5.0. Secondary outcomes included individual and composite cytopenias at months 3 and 6 after infusion, as well as relapse-free survival (RFS) and overall survival (OS), stratified by pre-infusion disease burden (DB; high, ≥25% marrow blasts; low,