Results  
Blinatumomab was administered as treatment for R/R ALL prior to HSCT in 9 patients (Table 1). The mean age at the time of administration was 10.1 years with a SD ±4.84. The distribution of cases by gender corresponds to 66% women (n= 5) and 44% men (n=4). All patients had an oncological diagnosis of ALL and 100% of them presented refractoriness and/or relapse. In the evaluation prior to the administration of Blinatumomab, 88.8% of the patients presented positive MRD (N=8) and 11.2% of the negative cases (N=1). No patient had extramedullary disease, the number of cycles of Blinatumomab received to achieve complete remission and negative MRD were different; 4 patients received 1 cycle (44%), 3 patients received 3 cycles (33%), and 2 patients received 2 cycles (22.2%), 56% of the cases achieved deep complete remission at the end of treatment or at the last consultation, 12% achieved a first complete remission with one blinatumomab cycle and 88% required a second or third cycle to achieve it.
Complications: 33% of the patients presented Cytokine Release Syndrome (n=3), with 22% being moderate grade and the most frequent (n=2) and 11% mild (n=1). 2 were admitted to the Pediatric Intensive Care Unit.
A 3-year disease-free survival and overall survival of 55% was determined (Graph 1). Brown and cols conclude that the comparing high and intermediate risk first relapse of B-ALL, post reinduction treatment with blinatumomab compared with chemotherapy followed by transplant is not statistically significant with disease free survival. Our series includes only refractory ALL patients which represent a very positive result. Adverse events are like the ones described in the literature.