Magenta Therapeutics Announces Collaboration with the National Marrow Donor Program/Be The Match to Advance Development of MGTA-145 for First-Line Mobilization of Stem Cells from Healthy Donors and Subsequent Patient Transplant

Collaboration focuses on clinical development of MGTA-145 for stem cell mobilization in allogeneic transplant in patients with blood cancers

Plan to initiate a Phase II trial of MGTA-145 in matched related donors for patients undergoing allogeneic transplant

CAMBRIDGE, Mass. & MINNEAPOLIS–(BUSINESS WIRE)–Magenta Therapeutics (Nasdaq: MGTA) and the National Marrow Donor Program® (NMDP)/Be The Match®, the global leader in providing a cure to patients with life-threatening blood and marrow cancers like leukemia, lymphoma and other diseases, today announced a clinical collaboration agreement to evaluate the potential utility of MGTA-145, Magenta’s investigational first-line stem cell mobilization program, for mobilizing and collecting hematopoietic stem cells from donors in a single day and then using them for allogeneic transplants in patients. This life-saving procedure is currently used in approximately 28,000 patients in the U.S. and Europe each year, but approximately 62,000 additional eligible patients do not receive an allogeneic transplant due to challenges, including difficulty with the donation process.

Under the collaboration, Magenta and NMDP/Be The Match will run a Phase 2 clinical trial of MGTA-145 to mobilize and collect hematopoietic stem cells from donors which will then be transplanted into patients with blood cancers in need of a stem cell transplant. The number of stem cells mobilized, engraftment function and benefit to disease will be measured. Magenta will retain all commercial rights to MGTA-145.

MGTA-145, a CXCR2 agonist, works in combination with plerixafor, a CXCR4 antagonist, to harness the physiological mechanism of stem cell mobilization into peripheral blood. MGTA-145 achieved all of the safety and activity endpoints in the recently completed Phase 1 trials in over 100 volunteers. Results showed that MGTA-145, in combination with plerixafor, enabled safe, same-day dosing, mobilization and collection of superior functional hematopoietic stem cells for transplant compared to the current standard of care.

The NMDP/Be The Match is the leading stem cell transplant organization in the United States and facilitates more than 6,500 stem cell transplants per year, through its contracted global network of 187 transplant centers. Through Be The Match BioTherapies®, the company also partners with cell and gene therapy companies, including Magenta, to advance the development and delivery of life-saving cell and gene therapies. This most recent collaboration builds on the existing partnership between the two organizations announced in May 2017, which is based on shared missions to ensure more patients receive curative stem cell transplants. This collaboration will combine Magenta’s leadership in developing medicines for immune system reset with NMDP/Be The Match’s expertise in managing more than 100,000+ stem cell transplants to-date, expansive global networks and the world’s largest and most diverse registry of more than 22 million potential blood stem cell donors.

“Magenta is delighted to build upon its successful partnership with NMDP/Be The Match through this clinical collaboration. The NMDP/Be The Match team brings unparalleled experience in stem cell transplant, operating the largest and most diverse marrow registry in the world, with a global network of 187 transplant centers. We are excited to collaborate with them to explore MGTA-145 in allogeneic transplant, which makes up nearly half of the transplants that take place each year in the U.S. and Europe,” said John Davis Jr., M.D., M.P.H., M.S., Head of Research & Development and Chief Medical Officer, Magenta. “MGTA-145 mobilizes robust numbers of functional stem cells in a single day, allowing donors to potentially avoid multiple visits to infusion centers or hospitals, which has been a major concern for donors during the COVID-19 pandemic. The large number of functional cells may also result in faster recovery and improved outcomes for patients undergoing a life-saving allogeneic transplant.”

“There is a significant need for new medicines for stem cell mobilization for patients and stem cell donors, and this need is only exacerbated during the COVID-19 pandemic as donors in particular prefer to avoid the hospital setting. Clinical data generated with MGTA-145 to date suggest that its robust mobilization of functional stem cells in a single day could improve both the donor experience and patient outcomes,” said Steven Devine, M.D., Chief Medical Officer, NMDP/Be The Match. “We are pleased to partner with Magenta to further transform the practice of stem cell transplant. We look forward to initiating this Phase 2 study.”

About Magenta Therapeutics

Magenta Therapeutics is a clinical-stage biotechnology company developing medicines to bring the curative power of immune system reset through stem cell transplant to more patients with autoimmune diseases, genetic diseases and blood cancers. Magenta is combining leadership in stem cell biology and biotherapeutics development with clinical and regulatory expertise, a unique business model and broad networks in the stem cell transplant world to revolutionize immune reset for more patients. Magenta is based in Cambridge, Mass. For more information, please visit www.magentatx.com. Follow Magenta on Twitter: @magentatx.

About the National Marrow Donor Program/Be The Match

We save lives through cellular therapy. As the global leader in providing a cure to patients with life-threatening blood and marrow cancers like leukemia, lymphoma and other diseases, we manage the world’s largest registry of potential blood stem cell donors and cord blood units. We work with a global network to connect patients to their donor match for a life-saving transplant. Through Be The Match BioTherapies, we partner with cell and gene therapy companies to support the development and delivery of new therapies. And, we conduct research through our research program, CIBMTR^® (Center for International Blood and Marrow Transplant Research^®), in collaboration with Medical College of Wisconsin. The NMDP/Be The Match is an investor in Magenta Therapeutics.

Magenta Therapeutics Forward-Looking Statements

This press release may contain forward-looking statements and information within the meaning of The Private Securities Litigation Reform Act of 1995 and other federal securities laws, including, without limitation, statements regarding the clinical collaboration agreement between Magenta and NMDP/Be The Match, including the timing, progress and success of the collaboration contemplated under the agreement, the commercial terms under the agreement, and Magenta’s strategy and business plan. The use of words such as “may,” “will,” “could,” “should,” “expects,” “intends,” “plans,” “anticipates,” “believes,” “estimates,” “predicts,” “projects,” “seeks,” “endeavor,” “potential,” “continue” or the negative of such words or other similar expressions can be used to identify forward-looking statements. The express or implied forward-looking statements included in this press release are only predictions and are subject to a number of risks, uncertainties and assumptions, including, without limitation, risks set forth under the caption “Risk Factors” in Magenta’s most recent Annual Report on Form 10-K filed on March 3, 2020, as updated by Magenta’s most recent Quarterly Report on Form 10-Q and its other filings with the Securities and Exchange Commission, as well as risks, uncertainties and assumptions regarding the impact of the COVID-19 pandemic to Magenta’s business, operations, strategy, goals and anticipated timelines, including, without limitation, Magenta’s ongoing and planned preclinical activities, ability to initiate, enroll, conduct or complete ongoing and planned clinical trials and timelines for regulatory submissions. In light of these risks, uncertainties and assumptions, the forward-looking events and circumstances discussed in this press release may not occur and actual results could differ materially and adversely from those anticipated or implied in the forward-looking statements. You should not rely upon forward-looking statements as predictions of future events. Although Magenta believes that the expectations reflected in the forward-looking statements are reasonable, it cannot guarantee that the future results, levels of activity, performance or events and circumstances reflected in the forward-looking statements will be achieved or occur. Moreover, except as required by law, neither Magenta nor any other person assumes responsibility for the accuracy and completeness of the forward-looking statements included in this press release. Any forward-looking statement included in this press release speaks only as of the date on which it was made. We undertake no obligation to publicly update or revise any forward-looking statement, whether as a result of new information, future events or otherwise, except as required by law.

Contacts

Magenta Therapeutics:
Manisha Pai, Vice President, Communications & Investor Relations

617-510-9193

[email protected]

Lyndsey Scull, Director, Corporate Communications

202-213-7086

[email protected]

NMDP/Be The Match:
Eric Hughes, Vice President, Corporate Marketing

763-406-8398

[email protected]