The FDA has granted Breakthrough Therapy Designation to Amgen’s investigational bispecific T cell engager (BiTE) antibody blinatumomab, for adults with Philadelphia-negative (Ph-) relapsed/refractory B-precursor acute lymphoblastic leukemia (ALL), a rapidly progressing cancer of the blood and bone marrow.

The Breakthrough Therapy Designation was based on the results of a phase II trial of 189 adult patients with Ph- relapsed/refractory B-precursor ALL treated with blinatumomab.

"There is a high unmet need for new medicines to treat relapsed and refractory ALL patients, who have very few treatment options," said Sean E. Harper, M.D., executive vice president of R&D at Amgen. "The results from the phase II trial evaluating blinatumomab in adult patients with relapsed or refractory ALL are encouraging and provide a strong basis for a regulatory filing later this year and potential approval in this serious disease."

The FDA states that Breakthrough Therapy Designation is intended to expedite the development and review of drugs for serious or life-threatening conditions. The criteria for Breakthrough Therapy Designation require preliminary clinical evidence that demonstrates the drug may have substantial improvement on at least one clinically significant endpoint over available therapy. A Breakthrough Therapy Designation conveys all of the fast-track program features, more intensive FDA guidance on an efficient drug development program, an organizational commitment involving senior managers and eligibility for rolling review and priority review.

In the U.S. alone, it is estimated that over 6,000 cases of ALL were diagnosed in 2013, and in the European Union, 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.