Rockville, MD, April 27, 2020 (GLOBE NEWSWIRE) --
MacroGenics, Inc. (MGNX), a clinical-stage biopharmaceutical company focused on discovering and developing innovative monoclonal antibody-based therapeutics for the treatment of cancer, today announced data related to flotetuzumab, an investigational, bispecific CD123 x CD3 DART® molecule being evaluated in patients with refractory acute myeloid leukemia (AML). The data will be presented during a plenary session at the American Association for Cancer Research (AACR) Virtual Annual Meeting I, taking place April 27-28, 2020.
“Patients with TP53 mutated AML respond poorly to induction therapy and have a dismal prognosis. The current study suggests that TP53 mutational status correlated with an immune-infiltrated tumor microenvironment that was associated with response to flotetuzumab in our ongoing Phase 1/2 study in refractory disease,” said Scott Koenig, M.D., Ph.D., President and CEO of MacroGenics. “This analysis further elucidates potential immune drivers of response to flotetuzumab and supports its potential for treating patients with particularly challenging disease and who have limited treatment options.”
The current study was conducted by Professor Sergio Rutella, M.D., Ph.D., FRCPath, at the John van Geest Cancer Research Centre at Nottingham Trent University in the UK, in collaboration with MacroGenics and NanoString Technologies, Inc. The data suggests that TP53 mutations in AML associate with an immune-infiltrated tumor microenvironment (TME) characterized by high expression of IFN-γ signaling molecules and immune checkpoints. This inflammation signature was previously found to be associated with response to flotetuzumab immunotherapy in a Phase 1/2 study in patients with AML who were refractory to induction treatment (primary induction failure). In this new study, among patients with TP53 mutated AML who were treated with flotetuzumab, 45.5% (5/11) showed evidence of anti-leukemic activity, including two patients with complete remission (CR), one patient with a CR with partial hematologic recovery (CRh), and one patient with morphologic leukemia-free state (MLFS) per International Working Group (IWG) criteria. Furthermore, median overall survival (OS) of flotetuzumab-treated patients with TP53 abnormalities was 4 months (range 1.25-21.25), compared to an estimated median OS of 1 month (Stichting Hemato-Oncologie voor Volwassenen Nederland, HOVON, Rotterdam, NL).
AACR Virtual Presentation
Title: TP53 abnormalities correlate with immune infiltration and are associated with response to flotetuzumab, an investigational immunotherapy, in acute myeloid leukemia
Session: VCTPL03 - Immunotherapy Clinical Trials 1
Date: April 27, 2020
Time: 1:25 pm - 1:35 pm ET
Location: AACR Virtual Annual Meeting I at www.aacr.org
After the presentation, Dr. Rutella’s slides will be available on the Events & Presentations page on MacroGenics’ website at http://ir.macrogenics.com/events.cfm.
About Acute Myeloid Leukemia
AML is a hematological malignancy characterized by differentiation arrest and uncontrolled clonal proliferation of neoplastic precursors that prevent normal bone marrow hematopoiesis. Nearly 20,000 new cases of AML are diagnosed in the U.S. each year, with a median age of 69 years at diagnosis. Approximately 40-50% of newly diagnosed patients fail to achieve a complete remission with intensive induction therapy (primary induction failure) or experience disease recurrence after a short remission duration (<6 months; early relapsed). A very small number of these patients are expected to respond to salvage therapy. Although new targeted agents have been approved for the treatment of frontline or relapsed/refractory AML in recent years, approximately 50% of patients have no known targetable mutations.
Flotetuzumab (also known as MGD006) is a clinical-stage bispecific DART molecule that recognizes both CD123 and CD3. CD123, the interleukin-3 receptor alpha chain, has been reported to be over-expressed on malignant cells in AML and other hematologic malignancies. The primary mechanism of action of flotetuzumab is believed to be its ability to redirect T lymphocytes to kill CD123-expressing cells. To achieve this, the DART molecule combines a portion of an antibody recognizing CD3, an activating molecule expressed by T cells, with an arm that recognizes CD123 on the target cells.
Flotetuzumab is currently being evaluated in the U.S. and Europe in a Phase 1/2 study (NCT02152956) designed to assess the safety, tolerability, and initial anti-leukemic activity of the molecule in patients with relapsed/refractory AML. Data from the ongoing clinical study were presented in December 2019 at the American Society of Hematology (ASH) Annual Meeting. The U.S. Food and Drug Administration has granted orphan drug designation to flotetuzumab for the treatment of AML. Pending discussions with FDA, MacroGenics plans to define a registration path for flotetuzumab in the U.S. for patients with AML who are refractory to induction treatment (primary induction failure) in the first half of 2020.
About MacroGenics, Inc.
MacroGenics is a clinical-stage biopharmaceutical company focused on discovering and developing innovative monoclonal antibody-based therapeutics for the treatment of cancer. The Company generates its pipeline of product candidates primarily from its proprietary suite of next-generation antibody-based technology platforms, which have applicability across broad therapeutic domains. The combination of MacroGenics' technology platforms and protein engineering expertise has allowed the Company to generate promising product candidates and enter into several strategic collaborations with global pharmaceutical and biotechnology companies. For more information, please see the Company's website at www.macrogenics.com. MacroGenics, the MacroGenics logo and DART are trademarks or registered trademarks of MacroGenics, Inc.
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Any statements in this press release about future expectations, plans and prospects for the Company, including statements about the Company's strategy, future operations, clinical development of the Company's therapeutic candidates, milestone or opt-in payments from the Company's collaborators, the Company's anticipated milestones and future expectations and plans and prospects for the Company and other statements containing the words "subject to", "believe", "anticipate", "plan", "expect", "intend", "estimate", "project", "may", "will", "should", "would", "could", "can", the negatives thereof, variations thereon and similar expressions, or by discussions of strategy constitute forward-looking statements within the meaning of Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934. Actual results may differ materially from those indicated by such forward-looking statements as a result of various important factors, including: the uncertainties inherent in the initiation and enrollment of future clinical trials, expectations of expanding ongoing clinical trials, availability and timing of data from ongoing clinical trials, expectations for the timing and steps required in the regulatory review process, expectations for regulatory approvals, the impact of competitive products, our ability to enter into agreements with strategic partners and other matters that could affect the availability or commercial potential of the Company's product candidates, business or economic disruptions due to catastrophes or other events, including natural disasters or public health crises such as the novel coronavirus (referred to as COVID-19), and other risks described in the Company's filings with the Securities and Exchange Commission. In addition, the forward-looking statements included in this press release represent the Company's views only as of the date hereof. The Company anticipates that subsequent events and developments will cause the Company's views to change. However, while the Company may elect to update these forward-looking statements at some point in the future, the Company specifically disclaims any obligation to do so, except as may be required by law. These forward-looking statements should not be relied upon as representing the Company's views as of any date subsequent to the date hereof.
Anna Krassowska, Ph.D., Vice President, Investor Relations & Corporate Communications
Jim Karrels, Senior Vice President, CFO