Overall survival for patients with acute lymphoblastic leukemia (ALL) was nearly doubled to 7.8 months from 4.0 months by treating patients with blinatumomab compared with standard of care. These findings were presented at the European Hematology Association 21st Congress.1
Intense chemotherapy achieves disease control in 90% of adult patients with ALL, but only half of these responders achieve a cure. Unfortunately, the outcome is dismal for patients with refractory disease or relapse after chemotherapy, despite undergoing more chemotherapy and/or allogeneic hematopoietic stem cell transplantation (aHSCT).
A new treatment option is now available. Blinotumomab is a bispecific antibody construct that engages patients’ own T cells to fight ALL cells. In a previous single-arm phase II trial, 43% of patients with relapsed or refractory ALL achieved disease control. That trial prompted accelerated FDA approval for blinatumomab.
In this trial (TOWER), researchers compared blinatumomab with standard chemotherapy, the standard of care, to determine if blinatumomab has a survival benefit for adults with relapsed or refractory ALL.
The trial randomized more than 400 patients with relapse/refractory ALL in Europe, North America, Asia, and Australia 2:1 to receive either blinatumomab or standard of care. The trial was stopped prematurely because overall survival nearly doubled with the study drug compared with standard of care; it would have been unethical to continue to offer standard of care to patients.
All subgroups of patients experienced increased survival time, including those whose disease relapsed after aHSCT and those who had received multiple different chemotherapy regimens. Side effects with blinatumomab were not more serious than those with chemotherapy.
The study found that blinatumomab is the first immunotherapy agent proven to extend the lives of patients with relapsed ALL compared with chemotherapy.
1. Topp MS, Stein A, Gokbuget N, et al. Blinatumomab improved overall survival in patients with relapsed or refractory Philadelphia negative B-cell precursor acute lymphoblastic leukemia in a randomized, open-label phase 3 study (TOWER). Presentation at: European Hematology Association 21st Congress; June 9-12, 2016; Copenhagen, Denmark. Abstract S149.