Acute Lymphoblastic Leukemia Drug Shows Promise in Phase 3 Trial

Blincyto treats adult patients with Philadelphia chromosome-negative relapsed or refractory B-cell precursor ALL.

A phase 3 trial for a leukemia therapy was able to meet its primary endpoint of improved overall survival, according to Amgen.

The open-label TOWER study administered blinatumomab (Blincyto) to adult patients with Philadelphia chromosome-negative relapsed or refractory B-cell precursor acute lymphoblastic leukemia (ALL), an aggressive blood and bone marrow cancer. The goal of the study was to explore the efficacy of Blincyto compared with standard of care (SOC) chemotherapy.

During the study, patients were randomized in a 2:1 ratio to receive either Blincyto or 1 of 4 protocol defined SOC chemotherapy treatments, at the choice of the investigator.

An independent data monitoring committee recommended the study end early for efficacy, which Amgen accepted.

"The FDA's breakthrough therapy designation and accelerated approval of BLINCYTO underscore the dire prognosis for these patients,” said Vice President of Amgen Sean E. Harper, MD. “This is the first study to demonstrate an overall survival benefit for these patients with an immunotherapy, and this is a tremendously rare achievement in relapsed and refractory ALL. We will work with regulatory authorities towards a full approval for BLINCYTO in this population."

Blincyto is a bispecific CD19-directed CD3 T cell engager antibody construct that attaches specifically to CD19 expressed on the cell surface of B-lineage origin and CD3 expressed on the surface of T cells.

The adverse events found within the study were consistent with the known safety profile of blinatumomab. Currently, the secondary endpoints are being evaluated and the data will be submitted for publication as well as to a future medical conference.