Micromet - Biting Cancer (Part II)

Tuesday, February 5th, 2008

BiTE Antibodies 

A BiTE (Bispecific T Cell Engager) antibody is a bi-specific antibody (bsAb) which directs T-cells to attack  cancer cells, by simultaneously binding the two cells. Upon binding, a physical link is created between  the two cells, which in turn triggers the T cell to attack the target cell. Every BiTE antibody has two binding arms, the first binds the CD3 receptor present on T-cells and the second binds a specific element on a cancer cell. The T-cell binding arm provides  the activity while the cancer binding arm provides the specificity. By changing the cancer binding arm, the BiTE antibody can be adapted not only from one type of cancer to another, but also from one target to another in the same type of cancer. Therefore, BiTE represents a universal and modular platform for producing bsAbs for an unlimited number of targets.

 As previously stated, bi-specific antibodies are aimed at recruiting immune cells against cancer. Therefore, one of the first decisions to be made concerns the type of immune cells to be recruited. The first attempts to develop bi-specific antibodies, mainly included recruiting T-cells, which are considered the most potent cells of the immune system. T cells play a critical role in the body’s efforts to eliminate malfunctioning cells such as cancer or virally infected cells, making them even more obvious candidates. (more…)

Seattle Genetics’ SGN-40 – The big comeback

Saturday, December 8th, 2007

 

Seattle Genetics’ lead product is SGN-40, an antibody targeting CD40 which is a very common receptor expressed on various hematological malignancies such as non-Hodgkin lymphoma [NHL], chronic lymphoid leukemia [CLL] and Multiple myeloma [MM]. Surprisingly, CD40 is also expressed on solid tumors such as breast and ovarian cancers, which may broaden SGN-40’s spectrum of application. Although everybody is smiling at the moment, the company has undergone quite a rollercoaster with this candidate, lasting more than 8 years and involving 3 different names for the same antibody.

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