Study Presented at 2009 AACR Meeting Highlights Potential Therapeutic Approach to Treat Patients Unresponsive to Erbitux and Vectibix

DENVER, CO, USA | April 22, 2009 | Micromet, Inc. (Nasdaq: MITI – News), a biopharmaceutical company developing novel, proprietary antibodies for the treatment of cancer, inflammation and autoimmune diseases, yesterday presented non-clinical data at the annual meeting of the American Association for Cancer Research (AACR). These non-clinical data indicate that after Micromet developed BiTE antibodies from the EGFR-specific monoclonal antibodies Erbitux® (cetuximab) and Vectibix® (panitumumab) they were highly active against KRAS-and BRAF-mutated human colorectal cancer cell lines(1). Recent clinical studies have shown that the chimeric monoclonal antibodies cetuximab(2,3) and panitumumab(3,4) are not active in colorectal cancer patients with tumor cells harboring mutations in KRAS and BRAF oncogenes. These two populations make up more than 40% of colorectal cancer patients.

Micromet’s researchers converted cetuximab and panitumumab into novel bispecific antibodies based on Micromet’s proprietary BiTE technology. Both of Micromet’s EGFR BiTE antibodies were able to direct T cells against cetuximab/panitumumab-resistant human colorectal cancer cells harboring KRAS and BRAF mutations, resulting in the destruction of these cancer cells. In mice, daily EGFR BiTE antibody doses as low as 0.1 microgram/kilogram were sufficient to prevent tumor growth from mutated human colorectal cancer cells. Studies in a relevant non-human primate species suggest that active serum levels of the cetuximab-based BiTE antibody are tolerated.

"The data show that our BiTE technology can overcome significant limitations of conventional monoclonal antibodies," commented Patrick Baeuerle, Chief Scientific Officer of Micromet. "Using commercially successful antibodies, we were able to produce novel, very potent EGFR BiTE antibodies. Based on these results, we believe that the development of an EGFR-directed BiTE antibody for the treatment of patients with KRAS- and BRAF-mutated colorectal cancer is now possible."

(1)Lutterbuese, R. et al. Highly efficient lysis of KRAS- and BRAF-mutated human colon cancer cells by T cell-engaging BiTE antibodies derived from anti-EGFR antibodies cetuximab and panitumumab AACR Annual Meeting 2009, abstract no. 3251
(2)Tol, J. et al., N. Engl. J. Med. 360 : 563-572 (2009)
(3)Di Nicolantonio, F. et al., J. Clin. Oncol. 26: 5705-5712 (2008)
(4)Amado, R.G. et al., J. Clin. Oncol. 26: 1626-1634 (2008)
(5)Bargou, R. et al., Science 321: 974-977 (2008)

About Micromet

Micromet, Inc. (www.micromet-inc.com) is a biopharmaceutical company with offices in Bethesda, MD and Munich, Germany. The Company is focused on developing novel, proprietary antibodies for the treatment of cancer, inflammation and autoimmune diseases. The Company’s novel antibody technology is based on its proprietary BiTE® antibody platform, representing a new class of antibodies that specifically activate T cells from the patient’s own immune system to eliminate cancer cells or other disease related cells. Four of the Company’s antibodies are currently in clinical trials, with the remainder of its product pipeline in preclinical development. The Company’s lead program is a BiTE antibody known as blinatumomab, or MT103. It is in a phase 2 clinical trial for the treatment of patients with acute lymphoblastic leukemia and a phase 1 clinical trial for the treatment of patients with non-Hodgkin’s lymphoma. Micromet’s second BiTE antibody in clinical development is MT110, which targets the epithelial cell adhesion molecule (EpCAM). The Company owns all rights to MT110, which is currently in a phase 1 clinical trial for the treatment of patients with solid tumors. The Company’s third clinical stage antibody is adecatumumab, also known as MT201, a traditional human monoclonal antibody that targets EpCAM-expressing solid tumors. Micromet is developing adecatumumab in collaboration with Merck Serono in a phase 1b clinical trial evaluating adecatumumab in combination with docetaxel for the treatment of patients with metastatic breast cancer. Micromet licensed a fourth clinical stage antibody, MT293, to TRACON Pharmaceuticals, Inc. MT293 is being developed in a phase 1 clinical trial for the treatment of patients with cancer. The Company’s preclinical programs include MT203 being developed in collaboration with Nycomed. MT203 is a traditional human antibody neutralizing the activity of granulocyte/macrophage colony stimulating factor (GM-CSF), which has potential applications in the treatment of inflammatory and autoimmune diseases, such as rheumatoid arthritis, psoriasis, or multiple sclerosis. Micromet has granted an exclusive option to Bayer Schering Pharma AG to license a BiTE antibody against an undisclosed solid tumor target. Additional BiTE antibodies, targeting CEA, CD33, Her2, EGFR and MCSP, respectively, are in different stages of preclinical development.

SOURCE: Micromet, Inc.