BETHESDA, Md., April 8 /PRNewswire-FirstCall/ -- Micromet, Inc. (Nasdaq: MITI - News), a biopharmaceutical company developing novel, proprietary antibodies for the treatment of cancer, inflammation and autoimmune diseases, today announced the publication of data in the peer-reviewed Journal of Immunotherapy (1) demonstrating the potent anti-tumor activity of a BiTE antibody binding to carcinoembryonic antigen (CEA) and to CD3 on T cells. Micromet and MedImmune are jointly developing MT111/MEDI-565, a CEA-specific BiTE, which is in pre-clinical development.
CEA, also called CD66e or CEACAM5, was selected as target antigen for development of a new BiTE antibody program because CEA is widely expressed on the surface of human carcinoma cells. In its soluble form, CEA serves as a marker in patients' blood for progression of colorectal and other forms of solid cancers. Conventional CEA-targeting antibodies can be blocked by soluble CEA and prevented from binding to CEA on the surface of cancer cells, thereby limiting antibody efficacy. The new study shows that novel BiTE antibodies have strong activity against CEA-expressing cancer cells in vitro and in animals, even in the presence of high levels of soluble CEA.
"Our new publication demonstrates not only that BiTE antibodies can be designed to bind to well established target antigens of conventional monoclonal antibodies, but also that BiTE antibodies have features that improve on the properties of conventional antibodies," commented Micromet's Chief Scientific Officer Dr. Patrick A. Baeuerle. "Many target antigens for cancer therapy are released by cancer cells into the blood stream, a process called shedding. The example of the CEA-specific BiTE antibody suggests that high levels of shed antigens may not pose a limitation for the anti-tumor activity of BiTE antibodies."
Reference
(1)Lutterbuese, R. et al. (2009). Potent control of tumor growth by CEA/CD3- bispecific single-chain antibody constructs that are not competitively inhibited by soluble CEA. Journal of Immunotherapy, April 1, 2009 [epub ahead of print]
About BiTE Antibodies
BiTE® antibodies are designed to direct the body's cytotoxic, or cell- destroying, T cells against tumor cells, and represent a new therapeutic approach to cancer therapy. Typically antibodies cannot engage T cells because T cells lack the appropriate receptors for binding antibodies. Previous attempts have shown the potential of T cells to treat cancer, but the therapeutic approaches tested to date have been hampered by cancer cells' ability to escape recognition by T cells. The use of BiTE antibodies that are specifically designed to engage T cells for attacking cancer cells may provide a more effective anti-tumor approach than conventional monoclonal antibodies. |
