Interim Phase 1 Data Presented at International Conference on Malignant Lymphomas Shows Dose Dependent Single Agent Activity

BETHESDA, MD, USA | June 5, 2008 | Micromet, Inc. (Nasdaq: MITI), a biopharmaceutical company developing novel, proprietary antibodies for the treatment of cancer, inflammation and autoimmune diseases, today presented an update of an ongoing phase 1 clinical trial for its BiTE(R) antibody blinatumomab (MT103/MEDI-538) at the 10th International Conference on Malignant Lymphomas (ICML) in Lugano, Switzerland. The new data(1) with the CD19-specific BiTE antibody show that all seven patients in the highest dose cohort tested so far (0.06 mg/m2/day) achieved complete or partial responses.

In the study, relapsed, incurable non-Hodgkin’s lymphoma (NHL) patients who previously failed a median of three (and up to 12) conventional therapies were treated with increasing doses of blinatumomab (MT103/MEDI-538) for four to eight weeks. Dose-dependent clinical activity was observed. At the recently completed cohort of 0.06 mg/m2 per day, seven out of seven patients showed either complete or partial responses. Remissions in this and the previous dose cohort continue in all patients, with the longest remission ongoing for more than one year. Most frequent side effects observed so far were lymphopenia, pyrexia, and leukopenia. Less common adverse events included transient neutropenia and thrombocytopenia, transient increase of liver enzymes, and central nervous system events, all of which were fully reversible.

"The high response rate and apparently durable remissions in this heavily pre-treated patient population support blinatumomab as a single agent therapy with the potential for accelerated development," said Micromet’s Senior Vice President and Chief Medical Officer, Dr. Carsten Reinhardt.

"ICML brings together thousands of the world’s leading specialists and researchers to present the latest advancements and insights in the treatment of malignant lymphomas," said Dr. Michael J. Keating, University of Texas MD Anderson Cancer Center professor of medicine, internist for the department of hematology, ICML advisory board member and a member of Micromet’s BiTE Antibody Scientific Advisory Board. "The data on blinatumomab show that it holds the promise to become an effective therapy for a number of lymphomas and leukemias."

(1) Bargou R. et al. (2008). Anti-CD19 BiTE Antibody MT103 (MEDI-538)
Induces Durable Objective Responses in Patients with Relapsed
Non-Hodgkin’s Lymphoma (NHL). Update from Ongoing Phase I Study
MT103-104. ICML, Lugano, 2008.

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 advanced BiTE antibody 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. Two additional BiTE antibodies, targeting CD33 and MCSP, are in preclinical development.

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 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 a patient’s own cytotoxic T cells, considered the most powerful "killer cells" of the human immune system, to eliminate cancer cells. Micromet is developing MT103 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.

SOURCE: Micromet, Inc.