Amgen has submitted a Biologics License Application (BLA) to the FDA seeking approval for its investigational bispecific T cell engager (BiTE) antibody construct, blinatumomab. The BLA is for the treatment of adults with Philadelphia-negative (Ph-) relapsed/refractory B-precursor acute lymphoblastic leukemia (ALL), a rapidly progressing cancer of the blood and bone marrow.

BiTE antibody constructs represent an innovative immunotherapy approach that helps the body's immune system target cancer cells. Blinatumomab, the first of the BiTE antibody constructs, has received both Orphan Drug designation and Breakthrough Therapy designation from the FDA for the treatment of ALL. The FDA states that Breakthrough Therapy designation, which is intended to expedite review of drugs for serious or life-threatening conditions, requires preliminary clinical evidence that demonstrates the drug may have substantial improvement over available therapies on at least one clinically significant endpoint.

The submission includes data from a phase II trial of adult patients with Ph- relapsed/refractory B-precursor ALL treated with blinatumomab, which successfully met its primary endpoint.

"Currently, there is no broadly accepted standard treatment regimen for adult patients with relapsed or refractory ALL," said Anthony S. Stein, M.D., clinical professor, hematology/oncology at City of Hope. "Blinatumomab has the potential to significantly advance treatment options for patients living with this difficult-to-treat disease, and the BLA submission marks an important step toward achieving this goal."

In the U.S., it is estimated that more than 6,000 cases of ALL will be diagnosed in 2014, and in the E.U., more than 7,000 cases of ALL are diagnosed each year. In adult patients with relapsed or refractory ALL, median overall survival is just three to five months.