Blinatumomab Prolongs Survival in MRD-Negative B-Cell Acute Lymphoblastic Leukemia

According to phase 3 findings of the phase 3 ECOG-ACRIN E1910 trial, blinatumomab (Blincyto) followed by consolidation chemotherapy led to a 58% reduction in the risk of death compared with standard consolidation chemotherapy alone in adult patients with newly diagnosed minimal residual disease (MRD)–negative B-cell acute lymphoblastic leukemia.

Results, which were presented during the 2022 American Society of Hematology (ASH) Annual Meeting, showed that the median overall survival (OS) with blinatumomab plus chemotherapy was not reached compared with 71.4 months with chemotherapy alone (HR, 0.42; 95% CI, 0.24-0.75; P = .003). OS rates at a median 3.5 years were 83% and 65%, respectively.

“This trial, E1910, showed for the first time, an overall survival advantage for adult patients with MRD-negative BCR-ABL–negative B-lineage acute lymphoblastic leukemia who receive blinatumomab combined with chemotherapy,” lead study author Mark R. Litzow, MD, a professor of medicine in the Division of Hematology at Mayo Clinic, said in a press briefing during the meeting. “We feel that this represented a new standard of care for this group of patients and should be incorporated into their standard therapy.”

Blinatumomab is a bispecific T-cell engager antibody that is designed to direct cytotoxic T cells to CD19-expressing cancer cells. The agent is currently approved for use in adult and pediatric patients with B-cell precursor acute lymphoblastic leukemia who are in remission but still have MRD, as well as in adult and pediatric patients with relapsed/refractory B-cell precursor disease.

In the phase 3 ECOG-ACRIN E1910 trial, patients underwent standard induction chemotherapy for about 2 months to induce a remission, followed by intensification chemotherapy for approximately 1 month to treat leukemia in the central nervous system. A total 224 patients were then randomized to receive intravenous blinatumomab for 2 monthly cycles, followed by 4 monthly cycles of consolidation chemotherapy and then 2 monthly cycles of blinatumomab (n = 112), or 4 monthly cycles of standard consolidation chemotherapy (n = 112). Maintenance chemotherapy was given in both arms for approximately 2.5 years.

Patients, who were aged between 30 and 70 years and had newly diagnosed, BCR-ABL1–negative, B-lineage acute lymphoblastic leukemia, were also tested for MRD via 6-color flow cytometry at the time of randomization, Litzow added. MRD negativity was defined as less than or equal to 0.01%.

Stratification factors included age, CD20 status, rituximab (Rituxan) use, and hematopoietic stem cell transplantation (yes vs no).

Twenty-two patients in each arm proceeded to allogeneic hematopoietic stem cell transplant.

Seventeen deaths occurred on the blinatumomab arm (relapse, n = 8; non-relapse mortality [NRM], n = 9) vs 39 on the chemotherapy-alone arm (relapse, n = 20; NRM, n = 17; unknown, n = 2).

Reference

Litzow MR, Sun Z, Paletta E, et al. Consolidation therapy with blinatumomab improves overall survival in newly diagnosed adult patients with B-Lineage acute lymphoblastic leukemia in measurable residual disease negative remission: results from the ECOG-ACRIN E1910 randomized Phase III National Cooperative Clinical Trials Network Trial. Blood. 2022;140(suppl 2):LBA-1. doi:10.1182/blood-2022-171751