CD19 CAR T-cell therapy for older patients with B-ALL: Phase I trial results

Results from a phase I, single-center trial (NCT05707273) evaluating an investigational CD19 chimeric antigen receptor (CAR) T-cell therapy as definitive consolidation in 18 older adults (≥55 years) with B-cell acute lymphoblastic leukemia (B-ALL) in first complete remission (CR1) following lymphodepletion with fludarabine + cyclophosphamide were published in Blood Advances by Aldoss et al. The primary objective was to assess the safety and tolerability of the CAR T-cell therapy. 

Key data: There were no dose-limiting toxicities (DLTs) or deaths during the study at the time of data cut off. Overall, 72% of patients developed transient Grade 1 cytokine release syndrome (CRS); there were no Grade ≥2 CRS events or immune effector cell-associated neurotoxicity syndrome (ICANS) events of any grade. Grade ≥3 treatment-emergent adverse events (TEAEs) included neutropenia (100%), lymphopenia (94%), leukopenia (94%), anemia (39%), thrombocytopenia (28%), and febrile neutropenia (11%). On Day 28 post-CAR T-cell infusion, all patients remained in measurable residual disease (MRD)-negative complete remission (CR). Estimated 18-month event-free survival (EFS) and overall survival (OS) were 84% (95% confidence interval [CI], 64.9%–100%) and 100% (95% CI, 100%–100%), respectively. 

Key learning: The investigational CD19 CAR T-cell therapy was well tolerated and potentially extended remission in older adults with MRD-negative B-ALL in CR1, supporting further investigation of early CAR T-cell therapy as consolidation for B-ALL.