Biotechnology giant Amgen has filed its investigational cancer immunotherapy blinatumomab in the US for the treatment of certain forms of acute lymphoblastic leukaemia (ALL).

Specifically, the Biologic License Application seeks approval to market the drug for patients with Philadelphia-negative (Ph-) relapsed/refractory B-precursor forms of the aggressive blood/bone marrow cancer. 

Blinatumomab is the first of Amgen’s BiTE antibody constructs, a novel immunotherapy approach under which antibodies are modified to engage two different targets simultaneously. The drug has already been awarded both ‘Orphan’ and ‘Breakthrough’ status by the Food and Drug Administration, indicating that it could offer a significant advance over available therapies on at least one clinically significant endpoint.

The submission includes data from a Phase II which successfully met its primary endpoint, showing 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.

"Currently, there is no broadly accepted standard treatment regimen for adult patients with relapsed or refractory ALL," noted Anthony Stein, clinical professor, Haematology/Oncology at City of Hope, adding that “blinatumomab has the potential to significantly advance treatment options for patients living with this difficult-to-treat disease”.  

In the US, it is estimated that more than 6,000 cases of ALL will be diagnosed in 2014. In adult patients with relapsed or refractory ALL, median overall survival is just three to five months, further highlighting the urgent need for new treatment options.