Micromet, Inc. announced the initiation of a pivotal, multi-centre study of the company's lead product candidate blinatumomab (MT103) in adult patients with minimal residual disease (MRD) positive B-precursor acute lymphoblastic leukaemia (ALL). 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.

"This trial is an important element of a broader clinical development plan aimed at establishing blinatumomab as an essential component of ALL therapy," said Christian Itin, Ph.D., Micromet's president and chief executive officer. "We view the initiation of this study to be a key milestone in the development of blinatumomab and a potentially important future value driver for the company."

This phase 2 multi-centre, single-arm study, also known as BLAST (Blinatumomab Adult ALL MRD Study of T cell engagement), is 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 MRD 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 enrolment at up to 70 leading cancer centres in Europe and the US will take approximately two years to complete.

"Historical experience suggests that the majority of ALL patients with MRD following front-line chemotherapy who do not receive a transplant will relapse within one year," said Nicola Goekbuget, M.D., Goethe University Hospital Frankfurt and the international study chair. "Results reported to date suggest that blinatumomab has the potential to fundamentally change the long-term clinical outcome for this difficult to treat disease."

Results from a phase 2 trial reported at the 2010 Congress of the European Haematology Association demonstrated that blinatumomab induced a prolonged haematologic relapse-free survival in patients with MRD-positive ALL and was well tolerated. Of 20 evaluable patients treated, 80% (16 out of 20) achieved a complete MRD response. As of June 2010, seven out of 11 evaluable non-transplanted patients were in hematologic remission with a median of nearly 18 months and ranging up to 23 months. Eight of the patients in the study received an allogeneic stem cell transplant after blinatumomab treatment, all of whom were alive and in remission, ranging up to 21 months. Overall, blinatumomab was well-tolerated. The most common adverse events (any grade) were fever, chills, decreases in immunoglobulins and headache.

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 leukaemia, mantle cell lymphoma and chronic lymphatic leukaemia and from the US Food and Drug Administration for the treatment of acute lymphoblastic leukaemia, chronic lymphocytic leukaemia and indolent B cell lymphoma.

Micromet, Inc. is a biopharmaceutical company focused on the discovery, development and commercialization of innovative antibody-based therapies for the treatment of cancer.