The US Food and Drug Administration (US FDA) has accepted for review Amgen's Biologics Licence Application (BLA) for the 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 leukaemia (ALL), a rapidly progressing cancer of the blood and bone marrow. As part of the acceptance, the FDA granted blinatumomab priority review with a Prescription Drug User Fee Act (PDUFA) action date of May 19, 2015.

A Marketing Authorization Application (MAA) has also been submitted to the European Medicines Agency (EMA) via the centralised procedure for approval to market blinatumomab for the treatment of adults with Ph- relapsed/refractory B-precursor ALL.

The submissions include data from a phase 2 trial of adult patients with Ph- relapsed/refractory B-precursor ALL treated with blinatumomab, which met its primary endpoint.

"The FDA's acceptance of our BLA submission and designation of priority review for blinatumomab underscores the need to provide new treatment approaches for adult patients with relapsed or refractory ALL, and we are encouraged by the Agency's expedited review," said Sean E. Harper, M.D., executive vice president of research and development at Amgen. "Blinatumomab has the potential to make a significant impact for these patients, and this milestone, along with other ongoing filings around the world, represents the potential of BiTE technology in cancers that are challenging to treat."

BiTE antibody constructs represent an innovative immunotherapy approach that helps the body's immune system target cancer cells. Blinatumomab, the first of the investigational BiTE antibody constructs, has received orphan drug designation from the EMA and FDA, and breakthrough therapy and priority review designation from the FDA for the treatment of ALL.

According to the FDA, priority review designation is assigned to applications for drugs that treat serious conditions and would, if approved, provide significant improvements in the safety or effectiveness of the treatment, diagnosis, or prevention of serious conditions. A priority review designation will set a goal date for taking action on an application within six months of receipt.

In the US, more than 6,000 cases of ALL will be diagnosed in 2014, and in the European Union, it is estimated that 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.

Bispecific T cell engager (BiTE) antibody constructs are a type of immunotherapy being investigated for fighting cancer by helping the body's immune system to detect and target malignant cells. The modified antibodies are designed to engage two different targets simultaneously, thereby juxtaposing T cells (a type of white blood cell capable of killing other cells perceived as threats) to cancer cells. BiTE antibody constructs help place the T cells within reach of the targeted cell, with the intent of allowing T cells to inject toxins and trigger the cancer cell to die (apoptosis). BiTE antibody constructs are currently being investigated for their potential to treat a wide variety of cancers.

Blinatumomab is an investigational BiTE antibody construct designed to direct the body's cell-destroying T cells against target cells expressing CD19, a protein found on the surface of B-cell derived leukaemias and lymphomas. Blinatumomab is the first of the BiTE antibody constructs and Amgen has received orphan drug designation from the FDA for the treatment of ALL, chronic lymphocytic leukaemia (CLL), hairy cell leukaemia, prolymphocytic leukaemia and indolent B-cell lymphoma and from the European Medicines Agency for the treatment of indolent B-cell lymphoma, ALL, CLL and mantle cell leukaemia (MCL). Blinatumomab is also being investigated for its potential to treat paediatric relapsed/refractory ALL, relapsed/refractory Philadelphia positive (Ph+) B-precursor ALL, minimal residual disease positive (MRD+) B-precursor ALL, relapsed/refractory non-Hodgkin's lymphoma (NHL), including relapsed/refractory diffuse large B-cell lymphoma (DLBCL).

Acute lymphoblastic leukaemia (ALL) is an aggressive cancer of the blood and bone marrow, the spongy tissue inside bones where blood cells are made. The disease progresses rapidly and affects immature blood cells. Worldwide, ALL accounts for more than 12 per cent of leukaemia. Of the 42,000 people diagnosed worldwide, 31,000 will die from the disease. Patients with ALL have abnormal white blood cells (lymphocytes) that crowd out healthy white blood cells, red blood cells and platelets, leading to infection, anaemia (fatigue), easy bleeding and other serious side effects.