European pivotal trial now enrolling at leading cancer centers

BETHESDA, MD, USA | December 6, 2010 | Micromet, Inc. (Nasdaq:MITI – News) today announced the presentation of updated results from a Phase 2 trial of the Company’s lead product candidate blinatumomab (MT103) in adult patients with minimal residual disease (MRD) positive acute lymphoblastic leukemia (ALL). An analysis of long-term efficacy data demonstrated that blinatumomab produced prolonged remissions in patients with ALL. As of November 2010, the hematologic disease free survival (DFS) was 60%, with a follow-up of up to 27.5 months. Blinatumomab is the first of a new class of agents called BiTE® antibodies, designed to harness the body’s T cells to kill cancer cells.

The data were reported in an oral presentation (abstract # 174) today at the 52nd American Society of Hematology (ASH) Annual Meeting in Orlando, FL.

"Blinatumomab continues to produce durable remissions in patients with ALL, with no relapses seen since the ASH 2009 Annual Meeting," said Christian Itin, Ph.D, President and CEO. "The experience to date supports our belief in blinatumomab’s potential to change the long-term outlook for patients with ALL. We look forward to further expanding our ALL development program in 2011."

Phase 2 Design and Results

This multi-center Phase 2 study evaluated the efficacy and safety of blinatumomab in adult patients with B precursor acute lymphoblastic leukemia. Enrolled patients had evidence of leukemic cells in the bone marrow following treatment with front-line chemotherapy, so called minimal residual disease (MRD). The primary endpoint of the study was molecular complete response. Key secondary endpoints included time to hematological relapse, time to molecular relapse and overall incidence and severity of adverse events. Patients received 15 micrograms per meter squared per day of blinatumomab for 28 days followed by two weeks off therapy over a six week treatment cycle. Patients received up to seven treatment cycles.

21 patients were treated in the study. Of 20 evaluable patients, 80% (16 out of 20) achieved a complete molecular response, all within the first cycle of treatment. Nine of the patients in the study received an allogeneic stem cell transplant, a toxic procedure that typically carries a high short-term risk of mortality. Notably, all nine transplanted patients were alive 100-days following the transplant.

Overall, blinatumomab was well-tolerated. Most adverse events occurred early, were transient and reversible. The most common clinical adverse events (any grade) were fever, headache and chills. Two patients discontinued treatment due to fully reversible adverse events; a seizure and a syncope (temporary loss of consciousness), respectively.

BLAST: European Pivotal Trial in MRD-Positive Adult ALL Patients

Based on the results reported to date, in September 2010, the Company initiated a Phase 2 multi-center, single-arm study, also known as BLAST (Blinatumomab Adult ALL MRD Study of T cell engagement), intended to evaluate the efficacy, safety and tolerability of blinatumomab in up to 130 evaluable adult patients with B-precursor ALL with MRD after treatment with front-line chemotherapy. Patients will receive 15 micrograms per meter squared per day of blinatumomab for 28 days followed by two weeks off therapy over a six week treatment cycle, for up to four treatment cycles. The primary endpoint of the study is molecular complete response. Secondary endpoints include 18 month relapse-free survival rate (for non-transplanted patients) and mortality rate within 100 days after stem cell transplantation. The Company currently expects that enrollment at up to 70 leading cancer centers in Europe and the U.S. will take approximately two years to complete. Additional information regarding the BLAST study is available at www.micromet.com or the U.S. government’s clinical trials database at http://www.clinicaltrials.gov.

About Blinatumomab

Blinatumomab (MT103) is a next-generation monoclonal antibody designed to direct the body’s cell destroying T-cells against CD19, a protein expressed on the surface of B-cell derived acute lymphoblastic leukemias and non-Hodgkin’s lymphomas. Micromet has received orphan drug designation from the European Medicines Agency for blinatumomab for the treatment of acute lymphoblastic leukemia, mantle cell lymphoma and chronic lymphatic leukemia and from the U.S. Food and Drug Administration for the treatment of acute lymphoblastic leukemia, chronic lymphocytic leukemia and indolent B cell lymphoma.

About Acute Lymphoblastic Leukemia

Acute Lymphoblastic Leukemia (ALL) is an aggressive cancer of the blood and bone marrow that afflicts 5,760 patients in the U.S. annually1. Patients with ALL have abnormal white blood cells (lymphocytes) that crowd out healthy white and red blood cells and platelets, leading to infection, anemia (fatigue), easy bleeding and other serious effects. The average five-year survival rate for adult ALL patients after first relapse is 7%. The presence of leukemic cells in the bone marrow following treatment with front-line chemotherapy, also known as minimal residual disease (MRD), is a recognized negative prognostic factor for patients with ALL. According to published results2, MRD-negative patients incurred a 6% risk of relapse compared to an 89% risk in patients remaining MRD positive after chemotherapy. There are currently no therapies approved for the treatment of MRD-positive ALL.

About Micromet

Micromet, Inc. is a biopharmaceutical company focused on the discovery, development and commercialization of innovative antibody-based therapies for the treatment of cancer. Its product development pipeline includes novel antibodies generated with its proprietary BiTE® technology, as well as conventional monoclonal antibodies. The Company’s lead product candidate blinatumomab (MT103) is currently the subject of a European pivotal trial in patients with minimal residual disease positive acute lymphoblastic leukemia. Micromet has collaborations with a number of leading pharmaceutical and biotechnology companies, including Bayer Schering Pharma, Boehringer Ingelheim, MedImmune, Merck Serono, Nycomed and sanofi-aventis. Additional information can be found at www.micromet.com.

References:

1. American Cancer Society. Cancer Facts and Figures 2009
2.
Raff et al. Molecular relapse in adult standard-risk ALL patients detected by prospective MRD monitoring during and after maintenance treatment. Blood. 2007109: 910-915

SOURCE: Micromet, Inc.