Micromet's Blinatumomab Produces High Rate of Durable Hematologic Complete Remissions in Adult Patients with Relapsed or Refractory Acute Lymphoblastic Leukemia

  • 75% of patients who received the selected dose and schedule achieved a complete remission, with no detectable leukemic cells remaining
  • Median survival not reached, with a median follow-up of 9.7 months

SAN DIEGO--(BUSINESS WIRE)--Dec 12, 2011 - Data presented today at the 53rd Annual American Society of Hematology (ASH) Annual Meeting in San Diego, CA, show that Micromet's blinatumomab more than doubled the complete remission rate produced by current standard therapies used to treat adult patients with relapsed or refractory B-precursor acute lymphoblastic leukemia (ALL) 1-6. 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.

In this phase 2 single-arm dose-ranging trial, 68% of evaluable patients (17/25) across all tested doses and schedules achieved a complete response (CR) or complete response with partial hematologic recovery (CRh*) following treatment with blinatumomab. Of the 12 evaluable patients who received the selected dose and schedule 75% (9 of 12) achieved a CR or CRh*. Notably, all responders also achieved a molecular response, or in other words, had no evidence of remaining leukemic cells detectable in the blood or bone marrow.

A first interim analysis of the time impact of blinatumomab treatment was conducted for the initial 18 patients enrolled to the trial. The median survival had not been reached, with a median follow-up period of 9.7 months. With combination chemotherapy, median survival typically ranges from 3 – 6 months1-5. 12 of the initial 18 patients had a CR or CRh* with a median duration of response of 7.1 months.

“In this study, blinatumomab has meaningfully altered the treatment outcome for patients with relapsed B-precursor ALL,” said Professor Max Topp, Department of Internal Medicine II, University of Wuerzburg and the chair of the study. “The difference in efficacy and improved tolerability that I have seen has been impressive compared to the standard of care."

The most common adverse events were grade 1 or 2 and included flu-like symptoms, pyrexia, headache, and tremor. These were most frequently seen at the onset of treatment in cycle one. The clinically most relevant adverse events were fully reversible central nervous system and cytokine release syndrome events that led to two discontinuations. There were no treatment related deaths.

Based on the results of this study, the Company initiated a global phase 2 study in this patient population in November 2011.

Study design

This phase 2 dose-ranging study evaluated the efficacy, safety and tolerability of blinatumomab in adult patients with B-precursor ALL who had relapsed following treatment with standard front-line chemotherapy or allogeneic stem cell transplant. Patients received blinatumomab for 28 days followed by two weeks off therapy over a six week treatment cycle, for up to five treatment cycles. Patients received a continuous intravenous infusion of blinatumomab at an initial dose of 5 or 15 micrograms per meter squared per day, ranging up to 30 micrograms for the remainder of the treatment. The primary endpoint of the study was the rate of CR/CRh*. Secondary endpoints included molecular response rate, duration of response and overall survival. As of October 10, 2011, 25 patients were evaluable for efficacy and safety. Enrollment in this study is now complete with a total of 36 patients treated. The Company plans to report updated results from this study in 2012.

Global Phase 2 Trial in Patients with Relapsed/Refractory ALL

Based on results of the phase 2 dose ranging study presented at ASH, in November 2011, the Company initiated a global phase 2, single-arm study intended to further evaluate the efficacy and safety of blinatumomab in approximately 65 patients with relapsed/refractory Philadelphia-negative B-precursor ALL. Patients will receive blinatumomab daily for 28 days followed by two weeks off blinatumomab over a six week treatment cycle. Patients who achieve CR or CRh* within two cycles of treatment will receive up to three additional cycles of consolidation treatment. The primary endpoint of the study is CR/CRh*. Secondary endpoints include duration of response and overall survival. The study will be conducted at approximately 40 leading cancer centers in the U.S. and Europe. The Company currently expects to complete enrollment in this trial by year end 2012.

Conference Call and Webcast

Micromet management will host a meeting for the investment community in San Diego on Monday, December 12 beginning at 12 PM PT to review the data presented at ASH. To participate in the event, please dial 888-567-1602 (domestic) or 201-604-5049 (international) and reference the Micromet ASH analyst event. The presentation will be available via webcast in the Investors and Media section of the Micromet website at: www.micromet.com. The archived webcast will be available for 30 days at www.micromet.com.

About Blinatumomab

Blinatumomab (MT103) is a next-generation monoclonal antibody-based therapeutic designed to direct the body's cell destroying T-cells against target cells expressing 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 5,330 patients in the U.S. annually7. 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. 50%ˆ’60%3,8 of patients will relapse following frontline therapy. 15 - 20%3 of patients have refractory disease, defined as failure to respond to frontline therapy. Standard chemotherapy is associated with a mortality rate of up to 23%9. The average five-year survival rate for adult ALL patients after first relapse is 7%4.

About Micromet, Inc.

Micromet is a biopharmaceutical company focused on the discovery, development and commercialization of innovative antibody-based therapies for the treatment of cancer. The Company is advancing a robust pipeline of novel therapeutics based on its proprietary BiTE® technology. 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 Amgen, Bayer HealthCare Pharmaceuticals, Boehringer Ingelheim, MedImmune, Nycomed and Sanofi.

Safe Harbor Statement

This release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995 and other federal securities laws. Any statements contained herein that do not describe historical facts are 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. These forward-looking statements include statements regarding the development and commercialization of blinatumomab, the potential safety, efficacy and utility of blinatumomab, the enrollment schedule for ongoing clinical trials, and the potential impact on the long-term survival of ALL patients treated with blinatumomab. You are urged to consider statements that include the words "will," "believes," "potential," "plans," "intends," “may,” “suggests,” or the negative of those words or other similar words to be uncertain and forward-looking. Factors that may cause actual results to differ materially from any future results expressed or implied by any forward-looking statements include the risk that blinatumomab does not demonstrate safety and/or efficacy in on-going or future clinical trials, delays in development and testing, including the risk that we will not obtain approval to market blinatumomab, and the risks associated with reliance on outside financing to meet capital requirements. These factors and others are more fully discussed in Micromet's Annual Report on Form 10-K, as amended, for the fiscal year ended December 31, 2010, and Micromet's Quarterly Report on Form 10-Q for the fiscal quarter ended September 30, 2011, filed with the SEC on November 8, 2011 as well as other filings by Micromet with the SEC. Micromet cautions you not to place undue reliance on any forward-looking statements, which speak only as of the date they are made. Micromet also disclaims any obligation to publicly update or revise any such statements to reflect any change in expectations or in events, conditions or circumstances on which any such statements may be based, or that may affect the likelihood that actual results will differ from those set forth in the forward-looking statements.

References:

 

1.   Kantarjian H, et al. Cancer. 2010;116:5568–5574.
2.   Advani AS, et al. Br J Haematol. 2010;151(5):430.
3.   Oriol A, et al. Haematologica. 2010;98(4):589-596.
4.   Fielding A, et al. Blood. 2007;109(3):944-950.
5.   O'Brien S, et al. Cancer. 2008;113:3186–3191.
6.   Topp MS, et al. Blood. 2011; 118(21):115 [abstract 252]
7.   National Cancer Institute, 2010 SEER ALL incidence data
8.   Annino L, et al. Blood. 2002;99:863-871.
9.   Bassan R, et al. J Clin Oncol. 2011;29(5):532-543
10.   Annino L, et al. Blood. 2002;99:863-871.

Contact: Micromet, Inc.
Jennifer Neiman, 240-235-0246
Director, Corporate Communications
jennifer.neiman@micromet.com

 

Posted: December 2011

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