To the Editor In their recent study,1 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.2,3 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.3
Shibusawa M, Kidoguchi K, Tanimoto T. Blinatumomab vs Chemotherapy Among Children With Relapsed Acute Lymphoblastic Leukemia. JAMA. 2021;326(4):359. doi:10.1001/jama.2021.8151
Coronavirus Resource Center
Customize your JAMA Network experience by selecting one or more topics from the list below.
Create a personal account or sign in to: