Phase 1 Data for Flotetuzumab, MacroGenics’ CD123 x CD3 DART® Molecule, Accepted for Oral Presentation at ESMO Congress 2017

ROCKVILLE, MD, July 17, 2017 --

MacroGenics, Inc. (NASDAQ: MGNX), a clinical-stage biopharmaceutical company focused on discovering and developing innovative monoclonal antibody-based therapeutics for the treatment of cancer, as well as autoimmune disorders and infectious diseases, today announced that data from the ongoing Phase 1 clinical study of flotetuzumab has been accepted for an oral presentation at the European Society for Medical Oncology Annual Congress, ESMO 2017, taking place in Madrid, Spain from September 8-12, 2017. The Phase 1 study (NCT02152956) is evaluating the safety and efficacy of flotetuzumab, a bispecific DART molecule that recognizes both CD123 and CD3, for the investigational treatment of acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS).

MacroGenics will present the following oral presentation:

Title:     Interim Results from a Phase 1 First-in-Human study of flotetuzumab, a CD123 x CD3 bispecific DART molecule, in AML/MDS

Date:     September 10, 2017

Time:    11:00 CEST

Full session details and data presentation listings for ESMO 2017 Congress can be found at http://www.esmo.org/Conferences/ESMO-2017-Congress/Programme.

About Flotetuzumab

Flotetuzumab (also known as MGD006 and S80880) is a clinical-stage molecule that recognizes both CD123 and CD3. CD123, the Interleukin-3 receptor alpha chain, has been reported to be over-expressed on cancer cells in a wide range of hematological malignancies including AML and MDS. 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 cancer cells.

Flotetuzumab is currently being evaluated in the U.S. and Europe in a Phase 1 dose-escalation study designed to assess the safety and tolerability of the molecule in patients with relapsed/refractory AML or MDS. MacroGenics retains full development and commercialization rights to flotetuzumab in the U.S., Canada, Mexico, Japan, South Korea and India. Servier participates in the development and has rights to flotetuzumab in all other countries. The U.S. Food and Drug Administration has granted orphan drug designation to flotetuzumab for the investigational 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, as well as autoimmune disorders and infectious diseases. The Company generates its pipeline of product candidates primarily from its proprietary suite of next-generation antibody-based technology platforms. 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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CONTACTS:
Jim Karrels, Senior Vice President, CFO
MacroGenics, Inc.
1-301-251-5172, [email protected]

Karen Sharma, Senior Vice President
MacDougall Biomedical Communications
1-781-235-3060, [email protected]