Amgen, engaged in developing and delivering important, cost-effective therapeutics based on advances in cellular and molecular biology, announced the top-line results of a phase 2 open-label, single-arm, multicenter trial to evaluate the efficacy and safety of Blincyto (blinatumomab) in adults with relapsed or refractory Philadelphia chromosome-positive (Ph+) B-cell precursor acute lymphoblastic leukemia (ALL).

The investigational study showed blinatumomab monotherapy induced a complete remission or complete remission with partial hematological recovery within two cycles of treatment in a clinically meaningful number of patients. Overall safety results from this study were consistent with the known blinatumomab safety profile. The data will be submitted to a future medical conference and for publication.

"These top-line results are encouraging and support blinatumomab as a potential treatment option for patients with relapsed or refractory Philadelphia chromosome-positive B-cell precursor acute lymphoblastic leukemia (ALL)," said Sean E. Harper, M.D., executive vice president of research and development at Amgen.

"We are hopeful that our comprehensive ALL development programme for blinatumomab, the first clinical and regulatory validation of the BiTE platform, will continue to demonstrate clinical effectiveness for patients with this serious disease."

Approximately one-fourth of adult ALL expresses the oncogenic protein BCR-ABL1 that results from the t (9;22) chromosome translocation known as the Philadelphia chromosome.

The study (NCT02000427) enrolled adult subjects with relapsed or refractory Ph+ B-cell precursor ALL. This was an open-label, single-arm, multicenter study consisting of a screening period, an induction treatment period (two cycles of blinatumomab), a consolidation treatment period (up to three additional cycles of blinatumomab for applicable subjects), and a safety follow-up visit 30 days after treatment. Following the safety follow-up visit, subjects were followed for response duration and survival every 3 months for 18 months or death, whichever occurred first.

Blincyto (blinatumomab) is the first bispecific CD19-directed CD3 T cell engager (BiTE) antibody construct product, and the first single-agent immunotherapy to be approved by the US Food and Drug Administration (FDA) for the treatment of patients with Philadelphia chromosome-negative (Ph-) relapsed or refractory B-cell precursor ALL, a rare and rapidly progressing cancer of the blood and bone marrow. Prior to approval, Blincyto was granted breakthrough therapy and priority review designations by the FDA.

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.