Results from a large multinational Phase 3 clinical trial testing the monoclonal antibody Blincyto (blinatumomab) showed that it is more effective than standard chemotherapy for treatment of relapsed or refractory B-cell precursor acute lymphoblastic leukemia (ALL).
The findings from the study “Blinatumomab versus Chemotherapy for Advanced Acute Lymphoblastic Leukemia” were recently published in The New England Journal of Medicine.
Blincyto, developed by Amgen, is an antibody that targets CD19, a protein largely expressed in B-cell lymphomas and leukemias, and enables immune T-cells to identify ALL cells and eliminate them. It is indicated for the treatment of Philadelphia chromosome-negative relapsed or refractory ALL.
“The activity of an immune-based therapy such as blinatumomab, which depends on functioning T-cells for its activity, provides encouragement that responses may be further enhanced and made durable with additional immune activation strategies,” Hagop Kantarjian, lead author of the study, said in a press release.
The clinical study (NCT02013167) led by The University of Texas MD Anderson Cancer Center, involved 101 centers in 21 countries, and enrolled 405 adult patients with ALL. Divided into two groups, the patients received either Blincyto or standard-of-care chemotherapy. Patients who had any other clinical conditions beside ALL, or had received therapy or a stem cell transplant before the study, were excluded.
The team observed that Blincyto-treated patients had a longer overall survival, surviving a median of 7.7 months, compared to 4.0 months in the chemotherapy-treated group.
The monoclonal antibody also had a positive impact on remission rates within 12 weeks after treatment. While 34% of patients in the Blincyto group had complete remission with full hematologic recovery, only 16% of those on chemotherapy achieved complete remission.
Results also showed that Blincyto resulted in a higher rate of event-free survival at six months compared to chemotherapy (31% vs. 12%), and a longer duration of remission (7.3 months vs. 4.6 months). Fewer patients treated with Blincyto had adverse effects.
“Among adults with relapsed ALL, remission rates are 18 to 44 percent with standard chemotherapy but the duration of remission is typically short,” Kantarjian said. “A major goal for these patients is to induce remission with sufficient duration to prepare for stem-cell transplantation.”
In this study, 24% of the patients in each treatment group underwent allogeneic stem cell transplants, he added.