Blinatumomab vs Chemotherapy Among Children With Relapsed Acute Lymphoblastic Leukemia

To the Editor In their recent study, Dr Locatelli and colleagues compared blinatumomab and standard intensive multidrug chemotherapy among children with high-risk B-cell acute lymphoblastic leukemia (B-ALL) in first relapse, before allogeneic hematopoietic stem cell transplant. Although the authors found an improved event-free survival in the blinatumomab group, several previous reports showed that an increased percentage of regulatory T cells in peripheral blood before the start of blinatumomab was associated with a reduced response to blinatumomab in patients with B-ALL relapse. A study investigating the use of flow cytometry in peripheral blood samples before blinatumomab therapy found that the median percentage of regulatory T cells was 4.82% (95% CI, 1.79%-8.34%) among 22 responders vs 10.25% (95% CI, 3.36%-65.9%) among 20 nonresponders. A regulatory T-cell percentage of less than 8.525% identified 100% of blinatumomab responders.
Source: JAMA - Category: General Medicine Source Type: research