Blinatumomab in pediatric patients with relapsed/refractory B-cell precursor acute lymphoblastic leukemia

Objective: Pediatric patients with relapsed or refractory acute lymphoblastic leukemia have a poor prognosis. We here assess the response rates, adverse events, and long-term follow-up of pediatric patients with relapsed/refractory acute lymphoblastic leukemia receiving blinatumomab. Methods: Retrospective analysis of a single-center experience with blinatumomab in 38 patients over a period of 10 years. Results: The median age at onset of therapy was 10 years (1-21 years). Seventy-one percent of patients had undergone at least one hematopoietic stem cell transplantation (HSCT) prior to treatment with blinatumomab. We observed a response to blinatumomab in 13/38 patients (34%). The predominant side effect was febrile reactions, nearly half of the patients developed a cytokine release syndrome. Eight events of neurotoxicity were registered over the 78 cycles (15%). To date, nine patients (24%) are alive and in complete molecular remission. All survivors underwent haploidentical HSCT after treatment with blinatumomab. Conclusions: Despite heavy pretreatment of most of our patients, severe adverse events were rare and response rates encouraging. Blinatumomab is a valuable bridging salvage therapy for relapsed or refractory patients to a second or even third HSCT.