MacroGenics Announces Flotetuzumab Publication in Blood Advances

ROCKVILLE, MD, Oct. 15, 2020 (GLOBE NEWSWIRE) --  

MacroGenics, Inc. (NASDAQ: MGNX), a clinical-stage biopharmaceutical company focused on discovering and developing innovative monoclonal antibody-based therapeutics for the treatment of cancer, today announced the publication of a manuscript in Blood Advances, a journal of the American Society of Hematology.  This represents the third publication of flotetuzumab data in 2020. Flotetuzumab (also known as MGD006), is an investigational, clinical-stage bispecific DART® molecule that recognizes both CD123 on leukemic cells and CD3 on T cells, with the intended result of T-cell-mediated killing of leukemic blasts. This most recent publication reports on the role of flotetuzumab in the immunotherapy of TP53-positive acute myeloid leukemia (AML).

It has previously been shown¹ that an inflammatory (IFN-γ-related) gene expression signature in patients with AML correlated with a lack of response to induction chemotherapy. The same gene signature was shown to be associated with an increased probability of this subset of patients to respond to flotetuzumab. As further described in the article titled “,” AML with TP53 abnormalities was also associated with immune infiltration in the tumor microenvironment (TME); moreover, patients with TP53 abnormalities derived benefit from flotetuzumab immunotherapy.

“Previous translational studies demonstrated that patients who failed to respond to induction therapy (primary induction failure, or PIF, AML) or those who relapsed within six months of achieving an initial remission (early relapsed, or ER, AML) had an immune-infiltrated TME that not only associated with resistance to standard-of-care chemotherapy regimens, but also with response to flotetuzumab,” said Sergio Rutella, M.D., Ph.D., FRCPath, John van Geest Cancer Research Centre, College of Science and Technology, Nottingham Trent University, Nottingham, United Kingdom. “Included in this PIF/ER AML population are patients harboring TP53 abnormalities, a particularly difficult to treat subset of AML associated with poor prognosis. Interestingly, these patients who responded poorly when treated with standard-of-care chemotherapy regimens appeared to benefit from flotetuzumab therapy.” 

“The results published today in Blood Advances, combined with data from previous articles published in Blood and Science Translational Medicine, further support our decision to conduct a pivotal study of flotetuzumab in AML patients who have previously experienced either a primary induction failure or an early relapse when treated with standard-of-care chemotherapy regimens. These individuals represent approximately 40-50% of all AML patients,” said Scott Koenig, M.D., Ph.D., President and CEO of MacroGenics. “Our single arm clinical trial is ongoing as an expansion of the Phase 1/2 study, for which we plan to enroll up to 200 patients. We plan to present interim results at a medical conference later this year.”



¹ “,” Blood, 2020; and “,” Science Translational Medicine, 2020.

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 PIF) or experience disease recurrence after a short remission duration (<6 months; early relapsed, or ER). 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. The discovery by the Rutella lab of an immunological gene signature in the AML tumor microenvironment forms the basis for a potential predictive biomarker for further clinical validation.

About Flotetuzumab

Flotetuzumab (also known as MGD006) is a clinical-stage bispecific, investigational 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. Data from the Phase 1/2 clinical study of flotetuzumab in patients with primary induction failure / early relapse (PIF/ER) AML were presented in December 2019 at the American Society of Hematology (ASH) Annual Meeting.  MacroGenics is conducting a single-arm, registration-enabling clinical study to evaluate flotetuzumab in up to 200 patients with PIF/ER AML, with complete remission (CR) and CR with partial hematological recovery (CRh) as the primary endpoint. The study will be conducted as a continuation of the ongoing Phase 1/2 study (NCT02152956; to be updated). The FDA has granted orphan drug designation to flotetuzumab for the treatment of AML.

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. For more information, please see the Company's website at  MacroGenics, the MacroGenics logo and DART are trademarks or registered trademarks of MacroGenics, Inc. 

Cautionary Note on Forward-Looking Statements

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. 

###