Magenta Therapeutics Appoints Lisa M. Olson as Chief Scientific Officer and Kevin B. Johnson as Senior Vice President, Head of Regulatory and Quality; Announces Transition of Jason Ryan, Chief Operating and Financial Officer

CAMBRIDGE, Mass.–(BUSINESS WIRE)–Magenta Therapeutics (NASDAQ: MGTA), a clinical-stage biotechnology company developing novel medicines to bring the curative power of immune reset to more patients, today announced the appointment of two new executives, Lisa M. Olson, Ph.D., as Chief Scientific Officer and Kevin B. Johnson, Ph.D., as Senior Vice President, Head of Regulatory and Quality. The Company also announced that Jason Ryan will transition from Chief Operating and Financial Officer to a consulting role for personal reasons while a search for his replacement is conducted.

“With the additions of Lisa and Kevin to our team, Magenta continues to deepen our technical expertise, bolstering our strong discovery, research, development and regulatory leadership to further our goal of delivering curative immune reset to patients in need,” said Jason Gardner, D.Phil., Chief Executive Officer and President, Magenta Therapeutics. “We are delighted to welcome Lisa and Kevin on board and look forward to their many contributions to the Magenta mission.”

As Chief Scientific Officer, Dr. Olson will provide strategic direction, oversight and execution for Magenta’s research and discovery efforts. This entails driving research strategy as Magenta continues to optimize its preclinical and clinical pipeline. She will join the executive team and will be a key member of the R&D leadership team.

Dr. Olson is an experienced senior-level pharmaceutical executive, with more than 20 years of experience in research and drug discovery. She comes to Magenta following 15 years in leadership positions at the AbbVie Bioresearch Center, most recently as Vice President, Immunology Discovery and Site Head, where she was responsible for all immunology discovery scientific and portfolio decisions, including new target approval, project advancement and licensing opportunities. Under her leadership, 15 molecules advanced into clinical development, including Upadacitinib that launched last year as Rinvoq™. Prior to AbbVie, she served as a Research Fellow and Group Leader in Inflammation & Immunology at Pfizer, Inc. She began her career as an Assistant Professor at Washington University School of Medicine, following a post-doctoral cardiovascular fellowship at the University of Chicago.

Dr. Olson holds a Ph.D. from the University of Illinois at Urbana-Champaign and a Bachelor of Science from Iowa State University.

As Senior Vice President, Head of Regulatory and Quality, Dr. Johnson will lead Magenta’s global regulatory strategy for the Company’s programs across multiple therapeutic areas. He will also be responsible for the oversight and accountability for all quality activities to enable Good Practice (GxP) functions across the portfolio. In this role, Dr. Johnson will provide strategic guidance and leadership to members of the R&D leadership team and the regulatory and quality teams for Magenta’s portfolio for all phases of product lifecycle.

Dr. Johnson bring years of regulatory, quality assurance and development leadership, coming to Magenta from Imara, Inc., where he served as Senior Vice President, Regulatory Affairs, Quality and Pharmacovigilance, leading successful requests for several regulatory designations with the U.S. Food and Drug Administration (FDA). Prior to his time at Imara, Dr. Johnson led global regulatory strategy and implementation for breakthrough therapy-designated rare disease development programs at Vtesse, later acquired by Sucampo. He also served as Director, Global Regulatory Affairs for Rare Diseases and Gene Therapies at GlaxoSmithKline, where he was part of on the international regulatory team for the European approval of the gene therapy Strimvelis® for ADA-SCID, and subsequently secured Regenerative Medicine Advanced Therapy (RMAT) designation for a retinal gene therapy product.

Dr. Johnson holds a Ph.D. in Neurobiology from the University of North Carolina (UNC) School of Medicine; a Master of Business Administration from the Kenan-Flagler School of Business, UNC; and a Bachelor of Science in Chemistry from the University of South Florida.

Along with these leadership team additions, Magenta also announced today that Jason Ryan, Chief Operating and Financial Officer, will step down from that role at the end of September. He will continue to contribute to Magenta in a consulting capacity, and the Company has commenced a search for a replacement.

“Jason has been a dynamic and reliable leader at Magenta since he joined us in 2019, leading finance and operations, contributing to our strategic planning efforts, and spearheading two financings during a period of significant growth,” said Gardner. “We are truly grateful for his contributions to the patients we seek to serve, our employees and business partners.”

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.

Forward-Looking Statement

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. 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 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. 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

Lyndsey Scull, Director, Corporate Communications

202-213-7086

lscull@magentatx.com

Dan Budwick

1AB

dan@1abmedia.com