BLINATUMOMAB A POSSIBLE NEW STANDARD-OF-CARE IN RELAPSED B-ALL
A Randomized Phase 3 Trial of Blinatumomab Vs. Chemotherapy As Post-Reinduction Therapy in High and Intermediate Risk (HR/IR) First Relapse of B-Acute Lymphoblastic Leukemia (B-ALL) in Children and Adolescents/Young Adults (AYAs) Demonstrates Superior Efficacy and Tolerability of Blinatumomab: A Report from Children’s Oncology Group Study AALL1331
Patrick A. Brown, MD (Johns Hopkins University, Baltimore MD) reported on a phase 3 trial comparing blinatumomab to chemotherapy for re-induction in pediatric and young adult patients with B-acute lymphoblastic leukemia (B-ALL). As allogeneic hematopoietic stem cell transplantation (HSCT) is the treatment of choice at first relapse in these patients, the group sought to determine whether blinatumomab could increase the proportion of patients eligible for HSCT by increasing the rate of MRD-negative second remission.
At first relapse, patients first received re-induction chemotherapy, and if they achieved <25% marrow blasts, they were randomized to either two intensive chemotherapy blocks or two blocks of blinatumomab and then all proceeded to HSCT if able. At a median 1.4 year follow-up, the intent-to-treat 2-year disease free-survival was 41 +/- 6.2% in the chemotherapy arm and 59.3 +/- 5.4% in the blinatumomab patients, leading to a p-value of 0.05. Greatly lengthened overall survival was also noted with blinatumomab over the control group: 2-year OS was improved by over 20%. After two blocks of chemotherapy, 21% of patients achieved MRD-negativity if they had MRD+ disease after one chemotherapy block, compared to 79% of patients with MRD-negative disease following a single block of blinatumomab (p<0.0001). No post-infusion toxic deaths occurred in the blinatumomab arm, compared to four in the other, with higher incidence of most other adverse events in the chemotherapy group as well. Notably, 73% of blinatumomab patients proceeded to HSCT, compared to only 45% of the chemotherapy cohort. Therefore, blinatumomab represents a superior option for treatment of pediatric/young adult B-ALL at first relapse.