Blinatumomab Improves Survival in Young Patients With High-Risk B-ALL
Blinatumomab leads to an improvement in event-free survival (EFS) when compared to consolidation chemotherapy in young patients with relapsed or refractory B-cell acute lymphoblastic leukemia (B-ALL), according to a study published in JAMA Oncology (2021 Mar 2. Epub ahead of print).
The study, conducted by Franco Locatelli, MD, PhD, Head of the Department of Paediatric Haematology and Oncology, IRCCS Bambino Children’s Gesù Hospital, Italy, and colleagues, aimed to determine EFS in young patients with high-risk first-relapsed B-ALL after a third consolidation course of blinatumomab, a CD3/CD19-directed bispecific T-cell engager molecule, compared to consolidation chemotherapy before allogeneic hematopoietic stem cell transplant.
From November 2015 to July 2019, 108 patients older than 28 days and younger than 18 years with high-risk first-relapse B-ALL in morphologic complete remission (M1 marrow, <5% blasts) or with M2 marrow (blasts 5% and <25%) were enrolled in this randomized phase 3 clinical trial at 47 centers across 13 countries. For the third consolidation, patients received either 1 cycle of blinatumomab (n = 54) for 4 weeks or consolidation chemotherapy (n = 54).
The primary end point was EFS and the secondary efficacy end point was overall survival (OS).
At the median follow-up of 22.4 months, there were significantly fewer incidents of events in the blinatumomab arm compared to the consolidation chemotherapy arm (31% vs 57%, p<.001). Death occurred in 8 patients (14.8%) in the blinatumomab group and 16 (29.6%) in the consolidation chemotherapy group, however, there were no fatal adverse events reported.
The OS hazard ratio (HR) was 0.43 (95% CI, 0.18-1.01). The blinatumomab arm also had a higher rate of minimal residual disease remission than consolidation chemotherapy (90% vs 54%).
The incidence of serious adverse events was lower in the blinatumomab arm (24.1%) than the consolidated chemotherapy group (43.1%), and there were fewer grade 3 or worse adverse events (57.4% vs 82.4%) reported. Adverse events that lead to discontinuing treatment were reported in 2 patients in the blinatumomab group.
“Among (young patients) with high-risk first-relapse B-ALL, treatment with 1 cycle of blinatumomab compared with standard intensive multidrug chemotherapy before allogeneic hematopoietic stem cell transplant resulted in an improved event-free survival at a median of 22.4 months of follow-up,” said Dr Locatelli et el.—Emily Bader