Imatinib and blinatumomab successfully rescued a pediatric B-ALL patient with TERF2::PDGFRB fusion resistant to dasatinib and chemotherapy

PDGFRB-rearranged acute lymphoblastic leukemia (ALL), an ABL-class Ph-like ALL subtype, typically exhibits chemotherapy resistance and poor prognosis. Precise diagnosis and therapies are crucial for improving outcomes. Here, we report a case of a 9-year-old male harboring a TERF2::PDGFRB fusion, exhibiting primary resistance to dasatinib, but achieving a remarkable response to imatinib. Subsequent combination therapy with blinatumomab induced sustained bone marrow remission. These findings highlight the variability in tyrosine kinase inhibitors (TKIs) sensitivity among PDGFRB-rearranged ALL cases, supporting early treatment switching upon poor response. Notably, the combination of blinatumomab and imatinib may be an effective treatment strategy for PDGFRB-rearranged ALL.