Outcomes for Australian children with relapsed/refractory acute lymphoblastic leukaemia treated with blinatumomab

Abstract

We report on the Australian experience of blinatumomab for treatment of 24 children with relapsed/refractory precursor B‐cell acute lymphoblastic leukaemia (B‐ALL) and high‐risk genetics, resulting in a minimal residual disease (MRD) response rate of 58%, 2‐year progression‐free survival (PFS) of 39% and 2‐year overall survival of 63%. In total, 83% (n = 20/24) proceeded to haematopoietic stem cell transplant, directly after blinatumomab (n = 12) or following additional salvage therapy (n = 8). Four patients successfully received CD19‐directed chimeric antigen receptor T‐cell therapy despite prior blinatumomab exposure. Inferior 2‐year PFS was associated with MRD positivity (20%, n = 15) and in KMT2A‐rearranged infants (15%, n = 9). Our findings highlight that not all children with relapsed/refractory B‐ALL respond to blinatumomab and factors such as blast genotype may affect prognosis.