Activity of blinatumomab in lymphoblastic leukemia with impaired T-cell immunity due to congenital immunodeficiency.

Blinatumomab, a single-chain, bispecific, T-cell-engaging antibody targeting CD19, is effective in B-precursor acute lymphoblastic leukemia (BCP-ALL), even in the context of chemotherapy-related partial T-cell immunodeficiency. We report 2 patients with BCP-ALL and congenital T-cell immunodeficiency, who obtained an excellent response to blinatumomab. The first, a 6-year-old girl with Schimke immuno-osseous dysplasia (SIOD) and combined immunodeficiency disorder (CID) obtained a minimum residual disease-negative (MRD-) remission of high hyperdiploid BCP-ALL with blinatumomab.