Amgen announced that the results of a prespecified interim analysis showed that the primary endpoint of improved overall survival was met in the phase 3 TOWER study. The randomized, open-label TOWER study evaluated the efficacy of Blincyto (blinatumomab) versus standard of care (SOC) in adult patients with Philadelphia chromosome-negative relapsed or refractory B-cell precursor acute lymphoblastic leukaemia (ALL). The independent data monitoring committee recommended, and Amgen has accepted, that the study end early for efficacy.

The Blincyto adverse events observed in the TOWER study were consistent with the known safety profile of Blincyto. Secondary endpoints are currently being evaluated. These interim data will be submitted to a future medical conference and for publication.

"The FDA's breakthrough therapy designation and accelerated approval of Blincyto underscore the dire prognosis for these patients. This is the first study to demonstrate an overall survival benefit for these patients with an immunotherapy, and this is a tremendously rare achievement in relapsed and refractory ALL," said Sean E. Harper, M.D., executive vice president of Research and Development at Amgen. "We will work with regulatory authorities towards a full approval for Blincyto in this population."


The TOWER study was a phase 3, randomized, open-label study investigating the efficacy of the BiTE antibody Blincyto versus SOC chemotherapy in adult subjects with Philadelphia chromosome-negative relapsed or refractory B-cell precursor ALL. Patients were randomized in a 2:1 ratio to receive Blincyto or treatment with investigator choice of one of four protocol defined SOC chemotherapy regimens. The primary endpoint was OS.

Blincyto is a bispecific CD19-directed CD3 T cell engager (BiTE) antibody construct that binds specifically to CD19 expressed on the surface of cells of B-lineage origin and CD3 expressed on the surface of T cells.

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.

Blincyto was granted breakthrough therapy and priority review designations by the US Food and Drug Administration, and is now approved in the US for the treatment of Philadelphia chromosome-negative relapsed or refractory B-cell precursor ALL. This indication is approved under accelerated approval. Continued approval for this indication may be contingent upon verification of clinical benefit in subsequent trials.

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.

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