US regulators have awarded Amgen's blinatumomab with breakthrough therapy status as a treatment for certain forms of acute lymphoblastic leukaemia (ALL).

The company is developing the drug, a so-called bispecific T cell engager (BiTE) antibody, for adults with Philadelphia-negative (Ph-) relapsed/refractory B-precursor acute lymphoblastic leukaemia (ALL), a rapidly progressing cancer of the blood and bone marrow.

Unmet need

The move indicates that the US Food and Drug Administration (FDA) believes blinatumomab has the potential to help address the current high level of unmet need for relapsed and refractory ALL patients, who have very few treatment options, on the back of promising Phase II data.

"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," said Sean Harper, executive vice president of Research and Development at Amgen.

43% showed complete response

Data from the trial showed a complete response (no leukaemia cells detectable with microscopy) rate of 43% in patients with relapsed/refractory ALL, including those with resistance to previous treatment approaches.

Last year in the US alone more than 6,000 cases of ALL were diagnosed, and in patients with relapsed or refractory forms median overall survival is just three to five months, highlighting the urgent need for new and more effective therapies.