Micromet and MedImmune announced today that the first patient has started treatment in a multi-center, phase 2 trial conducted in Germany investigating BiTE(R) antibody blinatumomab (MT103/MEDI-538) in patients with adult acute lymphoblastic leukemia (ALL)

BETHESDA and GAITHERSBURG, MD, USA | June 12, 2008 | Micromet, Inc. (Nasdaq: MITI) and MedImmune announced today that the first patient has started treatment in a multi-center, phase 2 trial conducted in Germany investigating BiTE(R) antibody blinatumomab (MT103/MEDI-538) in patients with adult acute lymphoblastic leukemia (ALL). Blinatumomab is a T cell engaging antibody targeting the CD19 antigen, which is only expressed on B cells. The clinical development program for blinatumomab was expanded to include ALL as an additional indication after data from an ongoing phase 1 clinical trial showed potent single-agent activity of the BiTE antibody in patients with late-stage non-Hodgkin’s lymphoma (NHL). These data were presented last December at the 2007 Annual Meeting of the American Society of Hematology (ASH), and an update of this trial was presented last week at the 10th International Conference on Malignant Lymphomas (ICML) in Lugano, Switzerland.

"This phase 2 clinical trial in ALL is an important step to assess activity of blinatumomab in aggressive forms of B cell malignancies and will help to determine the full therapeutic potential of this highly specific and potent BiTE antibody in human B cell cancers," said Carsten Reinhardt, M.D., senior vice president and chief medical officer of Micromet.

ALL is a very aggressive form of B cell leukemia. Patients with ALL are initially treated with complex and highly toxic chemotherapy regimens, which may be followed by bone marrow stem cell transplantation for eligible patients. Patients who have a low number of residual tumor cells in their bone marrow after chemotherapy (also known as "minimal residual disease" or MRD) are at a very high risk of early relapse. This phase 2 clinical trial recruits patients with MRD and will test whether blinatumomab can eliminate residual tumor cells and prolong the time to relapse. A systematic process has been established for the MRD screening of all ALL patients which are referred to the German ALL study group (GMALL). The patients identified in this screening as MRD-positive are now referred to the clinical trial.

"Improved treatments and reduction of relapse rate in patients with MRD-positive ALL represent a high medical need. Although CD19 is widely expressed in ALL, no therapies targeting CD19 are currently available," said Professor D. Hoelzer, chairman of the German ALL study group (GMALL).

About BiTE Antibodies

BiTE(R) 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. BiTE antibodies have been shown to induce an immunological synapse between a T cell and a tumor cell in the same manner as observed during physiological T cell attacks. These cytolytic synapses enable the delivery of cytotoxic proteins from T cells into tumor cells, ultimately inducing a self-destruction process in the tumor cell referred to as apoptosis, or programmed cell death. In the presence of BiTE antibodies, T cells have been demonstrated to serially eliminate tumor cells, which explains the activity of BiTE antibodies at very low concentrations and at very low ratios of T cells to target cells. Through the process of killing cancer cells, T cells proliferate, which leads to an increased number of T cells at the site of attack.

Several antibodies in Micromet’s product pipeline are BiTE antibodies and have been generated based on Micromet’s proprietary BiTE antibody platform. The most clinically advanced BiTE antibody program is MT103 (MEDI-538), targeting CD19, and has provided proof-of-concept in an ongoing phase 1 clinical study in patients with advanced non-Hodgkin’s lymphoma. MT110, which is targeting EpCAM (CD326) and is the first BiTE antibody with potential applications in the treatment of solid tumors, is in a phase 1 clinical trial in patients with lung or gastrointestinal cancers. Three additional BiTE antibodies, targeting CD33, CEA and MCSP, are in preclinical development.

About Blinatumomab

Blinatumomab, also known as MT103 or MEDI-538, is a BiTE(R) antibody being developed with the intent to treat certain types of B cell lymphomas. In February 2006, the U.S. Food and Drug Administration approved an orphan drug designation for blinatumomab for certain types of indolent B cell lymphoma. Blinatumomab also received orphan drug designation from the European Medicines Agency for mantle cell lymphoma and chronic lymphocytic leukemia. Blinatumomab specifically targets the CD19 antigen, which is present on B cells and B cell-derived tumors, but not on other types of blood cells or healthy tissues.

Micromet and MedImmune are developing blinatumomab under the terms of a 2003 agreement in which MedImmune has obtained exclusive rights for blinatumomab in North America. Micromet has retained the rights to blinatumomab outside of North America.

About Micromet, Inc.

Micromet, Inc. (www.micromet-inc.com) is a biopharmaceutical company developing novel, proprietary antibodies for the treatment of cancer, inflammation and autoimmune diseases. Four of its antibodies are currently in clinical trials, while the remainder of the product pipeline is in preclinical development. The BiTE(R) antibody blinatumomab, also known as MT103, is in a phase 2 clinical trial for the treatment of patients with acute lymphoblastic leukemia and in a phase 1 clinical trial for the treatment of patients with non-Hodgkin’s lymphoma. BiTE antibodies represent a new class of antibodies that activate the T cells of a patient’s own immune system to eliminate cancer cells. Micromet is developing blinatumomab in collaboration with MedImmune, Inc., a subsidiary of AstraZeneca plc. MT110 is the second BiTE antibody in clinical trials, and is being developed by Micromet in a phase 1 clinical trial for the treatment of patients with lung or gastrointestinal cancer. The third clinical stage antibody is adecatumumab, also known as MT201, a human monoclonal antibody which targets epithelial cell adhesion molecule (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. The fourth clinical stage antibody is MT293 which is licensed to TRACON Pharmaceuticals, Inc. and is being developed in a phase 1 clinical trial for the treatment of patients with cancer. Three additional BiTE antibodies, targeting CD33, CEA and MCSP, are in preclinical development. In addition, Micromet has established a collaboration with Nycomed for the development and commercialization of MT203, a human antibody neutralizing the activity of granulocyte/macrophage colony stimulating factor (GM-CSF), which has potential applications in the treatment of various inflammatory and autoimmune diseases, such as rheumatoid arthritis, psoriasis, or multiple sclerosis.

About MedImmune

MedImmune is wholly owned by AstraZeneca plc (LSE: AZN.L, NYSE: AZN) and is the worldwide biologics business for the AstraZeneca Group. The company has approximately 3,000 employees worldwide and is headquartered in Gaithersburg, Maryland. MedImmune strives to provide better medicines to patients, new medical options for physicians and rewarding careers to employees. Dedicated to advancing science and medicine to help people live better lives, the company is focused on infection, oncology, respiratory disease and inflammation, cardiovascular/gastrointestinal disease and neuroscience. For more information, visit MedImmune’s website at www.medimmune.com.

SOURCE: Micromet, Inc.