Carlsbad, CA, December 11, 2006 - Micromet, Inc. (NASDAQ: MITI), a biopharmaceutical company focusing on the development of novel, proprietary antibody-based products for cancer, inflammatory and autoimmune diseases, today announces interim data from an ongoing Phase 1 clinical trial of MT103 (also known as MEDI-538), a drug being developed for the potential treatment of patients with B cell-derived lymphomas and leukemias. Researchers will present the data, which indicated that MT103 is generally well tolerated at the dose levels administered, and cited the observation of clinical responses in patients who previously failed to respond to other therapies, during an oral presentation session on "Targeted Therapy of Non-Hodgkin-Lymphoma (NHL)" today at 4:00pm EST in the "Valencia B/C" room at the 48th Annual Meeting of the American Society of Hematology (ASH). MT103 is the first BiTE® molecule being tested in a clinical trial. BiTE® molecules are a new class of antibody-based drugs developed by and proprietary to Micromet. BiTE® molecules consist of bispecific single-chain antibodies with the ability to engage T cells for killing tumor cells. With one of its binding sites, MT103 targets CD19 on B cells and B cell-derived tumors like NHL, and with its second binding site engages T cells through their CD3 complex. This process triggers the T cell to attack and kill the CD19 positive cells. The Phase 1 clinical trial is evaluating the safety and tolerability of MT103 with continuous infusion over a 4- to 8-week period at escalating dose levels in patients with relapsed, indolent Non-Hodgkin Lymphoma (NHL). The data presented at ASH were derived from 22 patients with relapsed NHL, who had previously received a median of 4 different regimens of chemo- and immuno-therapy, including rituximab. In the first 4 dose levels (0.5, 1.5, 5 and 15 µg/m2/24h), no maximum tolerated dose was reached. Recruitment for this clinical trial is continuing. Based on the current clinical data, 4 of 8 evaluable patients at the highest dose tested so far (dose level 4: 15 µg/m2/24 h) showed a clinically relevant reduction in tumor lesions (1 complete response, 2 partial responses, and 1 minimal response which is defined in the protocol as 25 to 50 percent decrease in tumor mass). Also, investigators observed a reduction of circulating B cells, which appeared to be correlated with increasing doses, with full depletion of B cells observed in all 8 evaluable patients at dose level 4. Further, all patients at dose level 4 with bone marrow infiltration at initial screening showed a reduction or complete disappearance of lymphoma cells from bone marrow after treatment with MT103. MT103 was well tolerated by the patients in the clinical trial. Overall, the most frequent adverse events related to the administration of MT103 were lymphopenia, leukopenia, fever and elevation of liver enzymes. The most frequent adverse events of grade 3 or higher were lymphopenia in 12 patients (54.5 percent) and leukopenia in 9 patients (40.9 percent). "It is highly encouraging to see first signs of clinical activity in this Phase 1 clinical trial investigating MT103 as a single agent for the treatment of patients suffering from non-Hodgkins lymphoma, in particular considering that these patients already had failed several other treatment regimens" said Dr. Ralf Bargou, the principal investigator of the trial from the University of Wuerzburg, Germany. "The tumor responses seen in this ongoing clinical trial clearly provide clinical proof-of-concept for MT103 and the BiTE® platform" added Dr. Carsten Reinhardt, Senior Vice President, Clinical Development of Micromet, Inc. "We expect to generate more data with MT103 in the on-going clinical trial and also plan to explore the potential of other BiTE® molecules for the treatment of solid tumors." The optimal treatment schedule and the optimal biological dose will be further assessed on the basis of clinical response and pharmacodynamic data from the ongoing dose escalation study. The compound is being co-developed with MedImune, Inc.. MedImmune plans to start a Phase 1 clinical trial in the United States in the first half of 2007, while Micromet expects to initiate a Phase 2 clinical trial in Europe for an additional indication in the second half of 2007. About BiTE® BiTE® molecules are a new generation of antibody-based drugs designed to direct the body's cytotoxic, or cell-destroying, T cells against tumor cells. BiTE® molecules represent a new therapeutic approach to cancer therapy. BiTE® molecules 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 mediate the delivery of cytotoxic proteins called perforin and granzymes 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® molecules, T cells have been demonstrated to serially eliminate tumor cells, which explains the activity of BiTE® molecules at very low concentrations and at very low ratios of T cells to target cells. Through the killing process, T cells start to proliferate at the site of the tumor, which leads to an increased number of T cells at the site of attack improving the ratio of T cells to tumor cells. About MT103 (MEDI-538) MT103, which is being co-developed with MedImmune, Inc. as MEDI-538, is a BiTE® molecule being developed with the intent to treat certain types of B-cell lymphomas. In February 2006, the U.S. Food and Drug Administration (FDA) approved an orphan drug designation for MT103/MEDI-538 for the treatment of indolent B-cell lymphoma, excluding chronic lymphocytic leukemia and Non-Hodgkin Lymphoma with central nervous system involvement. MT103/MEDI-538 also received orphan drug designation from the EMEA for the treatment of mantle cell lymphoma and chronic lymphatic lymphoma. BiTE® molecules are part of a novel class of antibody derivatives that may have the potential to selectively direct and activate an individual's own immune system to act against cancer cells. This action is believed to occur as a result of the BiTE® molecule's stimulation of T cells (a very potent type of white blood cell) to target and destroy cancer cells that over-express a specific antigen. MT103/MEDI-538 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. About Micromet, Inc. Micromet, Inc. is a biopharmaceutical company focusing on the development of novel, proprietary antibody-based products for cancer, inflammatory and autoimmune diseases. Two product candidates are currently in clinical trials. Adecatumumab (MT201) is a recombinant human monoclonal antibody which targets EpCAM expressing tumors with which Micromet has completed two phase 2 clinical trials, one in patients with breast cancer and the other in patients with prostate cancer. In addition, a phase 1 trial evaluating the safety and tolerability of MT201 in combination with docetaxel is currently ongoing in patients with metastatic breast cancer. MT103 (MEDI-538), which is the first product candidate based on the novel a BiTE® product development platform, is being evaluated in a phase 1 clinical trial for the treatment of patients with non-Hodgkins lymphoma in conjunction with MedImmune. The BiTE® product development platform is based on a unique, antibody-based format that leverages the cytotoxic potential of T cells, the most powerful 'killer cells' of the human immune system. Micromet has established collaborations with MedImmune and Serono. More information: www.micromet-inc.com Contact Information: Investor Contacts: Media Contacts: Ines-Regina Buth Europe: Evelyn Wolf +1 760-494-4235 (US) +49 (0)89 895277 220 +49 (0)89 895277 221 (Europe) [email protected] [email protected] US: Susan Noonan (212) 966-3650 [email protected] Forward-Looking Statements This release contains certain forward-looking statements that involve risks and uncertainties that could cause actual results to be materially different from historical results or from any future results expressed or implied by such forward-looking statements. Such forward-looking statements include statements regarding the efficacy, safety, and intended utilization of Micromet's MT103 product candidate, the conduct and results of future clinical trials, plans regarding regulatory filings, future research, discovery and clinical trials of new product candidates, and plans regarding partnering activities. Factors that may cause actual results to differ materially include the risk that product candidates that appeared promising in early research and clinical trials do not demonstrate safety and/or efficacy in larger-scale or later clinical trials, the risk that we will not obtain approval to market our products, the risks associated with reliance on outside financing to meet capital requirements, and the risks associated with reliance on collaborative partners for future revenues under the terms of our existing collaboration agreements. You are urged to consider statements that include the words "may," "will," "would," "could," "should," "believes," "estimates," "projects," "potential," "expects," "plans," "anticipates," "intends," "continues," "forecast," "designed," "goal," or the negative of those words or other comparable words to be uncertain and forward-looking. These factors and others are more fully discussed in our periodic reports and other filings with the SEC, including the "Risk Factors" sections of such reports. Any forward-looking statements are made pursuant to Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended, and, as such, speak only as of the date made. Micromet undertakes no obligation to publicly update any forward-looking statements, whether as a result of new information, future events or otherwise.