Survival Benefits of Early Treatment With Blinatumomab in Adult Patients With Relapsed/Refractory B-Cell Acute Lymphoblastic Leukemia.

Background: This study analyzed the long-term survival of blinatumomab-treated patients in the salvage setting and factors affecting treatment outcomes.

Methods: Clinical data were collected from adult patients with relapsed/refractory (R/R) B-cell acute lymphoblastic leukemia (ALL) who were administered blinatumomab as a salvage therapy.

Results: A total of 138 patients with R/R B-cell ALL were analyzed, of which 99 patients were diagnosed with Philadelphia chromosome-negative (Ph-negative) ALL, and 39 patients were treated for Ph-positive ALL. After 2 cycles of blinatumomab therapy, 45 patients (45.5%) achieved complete remission (CR), and 10 (10.1%) showed complete remission with partial hematological response (CRh), while 32 (32.3%) showed no response in the Ph-negative ALL subgroup. In the Ph-positive ALL subgroup, 18 patients (46.2%) achieved CR, and 4 (10.3%) achieved CRh, while 13 (33.3%) were refractory. In the Ph-negative ALL subgroup, for both relapse-free survival (RFS) and overall survival (OS), PLT < 100.0 (× 10³/µL) and number of prior treatment lines ≥ 2 were adverse prognostic factors, while proceeding to allo-SCT was a favorable factor. In the Ph-positive ALL subgroup, number of prior treatment lines ≥ 3 and refractory status at blinatumomab initiation were adverse factors for RFS. PLT < 100.0 (× 10³/µL) and refractory status were adverse factors, while proceeding to allo-SCT was a favorable factor for OS.

Conclusion: Early use of blinatumomab showed survival benefits in both Ph-negative and Ph-positive ALL subgroups in the salvage setting. Proceeding to allo-SCT after blinatumomab could improve long-term outcomes in patients with Ph-negative ALL.