Low leukemia burden improves blinatumomab efficacy in patients with relapsed/refractory B‐cell acute lymphoblastic leukemia. Issue 9 (24th February 2023)

• Record Type: Journal Article
• Authors: Queudeville, Manon; Stein, Anthony S.; Locatelli, Franco; Ebinger, Martin; Handgretinger, Rupert; Gökbuget, Nicola; Gore, Lia; Zeng, Yi; Gokani, Priya; Zugmaier, Gerhard; Kantarjian, Hagop M.
• Is Part Of: Cancer. Volume 129:Issue 9(2023)
• Page Start: 1384
• Page End: 1393
• Publication Date: 2023-02-24
• Subjects: acute lymphoblastic leukemia -- bispecific antibodies -- blinatumomab -- leukemia burden -- treatment efficacy; Cancer -- Periodicals; Cancer -- Cytopathology -- Periodicals; 616.99405
• DOI: 10.1002/cncr.34667
• Languages: English
• ISSNs: 0008-543X

Abstract

Abstract: Background: A lower baseline bone marrow blast percentage (bBMB%) is associated with better outcomes in patients with B‐cell acute lymphoblastic leukemia (B‐ALL) receiving blinatumomab. The objective of this analysis was to investigate the association between bBMB% and treatment outcomes in relapsed/refractory (R/R) B‐ALL. Methods: Data from five trials of blinatumomab for R/R B‐ALL were pooled for analyses. Patients were placed in one of three groups: group 1, ≥50% bBMBs; group 2, ≥25% to <50% bBMBs; group 3, ≥5% to <25% bBMBs. Response and survival outcomes were compared between groups. Results: Data from 683 patients (166 pediatric, 517 adult) were analyzed. Collectively, patients in groups 2 and 3 had significantly higher odds of achieving a complete remission (CR) (odds ratio [OR], 3.50 [95% confidence interval (CI), 2.23–5.48] and 3.93 [95% CI, 2.50–6.18], respectively; p < .001) and minimal/measurable residual disease response (OR, 2.61 and 3.37, respectively; p < .001) when compared with group 1 (reference). Groups 2 and 3 had a 37% and 46% reduction in the risk of death (hazard ratio [HR], 0.63 and 0.54, respectively; p < .001) and a 41% and 43% reduction in the risk of an event (relapse or death) (HR, 0.59 and 0.57, respectively; p < .001) compared with group 1. No significant differences in response or survival outcomes were observed between groups 2 and 3. Seven of nine patients whose bBMB% was lowered to <50% with dexamethasone achieved CR with blinatumomab. Conclusion: Any bBMB% <50% was associated with improved efficacy following blinatumomab treatment for R/R B‐ALL. Abstract : Patients with a baseline leukemia burden of <50% bone marrow blasts achieved better outcomes with blinatumomab compared with those who had ≥50% blasts. There was no statistical difference in clinical outcomes with blinatumomab in patients who had ≥5% to <50% bone marrow blasts at baseline.