Prime Medicine PRME

Allan Reine, M.D. has served as our Chief Executive Officer and a member of our board of directors since May 19, 2025. Prior to joining Prime, Dr. Reine served as Chief Financial Officer of Foghorn Therapeutics Inc. from September 2019 to January 2024, and as Chief Financial Officer of Pieris Pharmaceuticals, Inc. from August 2017 to September 2019. From August 2012 through August 2017, Dr. Reine was a portfolio manager at Lombard Odier Asset Management, where he ran a healthcare portfolio focused on biotechnology and pharmaceutical companies. Before joining Lombard Odier, from 2003 through August 2012, Dr. Reine served as a healthcare portfolio manager at various funds, including Citi Principal Strategies, SAC Capital, Trivium Capital and Alexandra Investment Management. Dr. Reine began his career in 2001 at CIBC World Markets where he worked in both biotechnology investment banking and biotechnology equity research. Dr. Reine received his M.D. from the University of Toronto and his B.Sc. in Statistical Sciences from the University of Western Ontario. Effective as of April 16, 2026, Allan Reine, M.D. will step down from the role of principal financial officer and will continue in his role of Chief Executive Officer and principal executive officer of the Company.

Ann L. Lee, Ph.D. has served as our Chief Technical Officer since October 2021. Prior to that, Dr. Lee served as Senior Vice President and Head of Cell Therapy Development and Operations at Bristol-Myers Squibb, or BMS, from November 2019 to July 2021, as Executive Vice President of Cell Therapy Development and Operations at Celgene Corporation, a biopharmaceutical company, from April 2018 to November 2019 and as Executive Vice President of Technical Operations at Juno from November 2017 to April 2018. From April 2009 to November 2017, Dr. Lee served as Senior Vice President and Global Head of Pharma Technical Development at Genentech, Inc., a Roche Group subsidiary and a biotechnology company. She currently serves on the board of directors and audit and compensation committees of Coya Therapeutics, Inc. Dr. Lee received her Ph.D. in biochemical engineering from Yale University and her B.S. in chemical engineering from Cornell University.

Jeffrey D. Marrazzo has served as a member of our Board since May 2023 and as Executive Chair of our Board since May 2025. Currently, Mr. Marrazzo chairs the board of directors of several privately-held biotechnology companies, including Dispatch Biotherapeutics and nChroma Bio. Previously, Mr. Marrazzo served as co-founder and Chief Executive Officer of Spark Therapeutics, Inc. from May 2013 to April 2022 and as a member of its board of directors from May 2013 to December 2019. In addition, Mr. Marrazzo launched and was Chief Business Officer of the U.S. division of Molecular Health, Inc. from 2011 to 2013. Mr. Marrazzo was part of the founding management of Generation Health from 2009 to 2011, up to and through the acquisition of a majority of the company's shares by CVS Caremark. From 2008 to 2009, Mr. Marrazzo served as an employee and independent consultant to the business development and finance teams at Tengion Inc. and, from 2011 to 2013, Mr. Marrazzo served as an independent consultant to the Children's Hospital of Philadelphia, or CHOP. Previously, Mr. Marrazzo served as healthcare advisor to former Pennsylvania Governor Edward G. Rendell and as an IBM management consultant to global pharmaceutical companies. Mr. Marrazzo holds a B.S.E. and B.A. in Systems Science and Engineering and Economics from the University of Pennsylvania and a dual M.B.A./M.P.A. from The Wharton School and Harvard University.

Michael A. Kelly has served as a member of our Board since November 2021. Mr. Kelly is currently acting as Founder & President of Sentry Hill Partners, LLC, a global life sciences transformation and management consulting business founded by Mr. Kelly in January 2018. From February 2003 to December 2017, he was a senior executive of Amgen, Inc., a biotechnology company, where he most recently served as Senior Vice President, Global Business Services and Vice President & Chief Financial Officer, International Commercial Operations. He also serves on the boards of directors of: Amicus Therapeutics, Inc., a biotechnology company, which he joined in December 2020; DMC Global Inc., a composite materials and oil field products company, which he joined in July 2020; NeoGenomics Laboratories, Inc., a genetics testing company, which he joined in July 2020, and nChroma Bio, Inc., a biotechnology company, which he joined in December 2024. Mr. Kelly previously served on the boards of directors of Aprea Therapeutics, Inc., a biotechnology company, from September 2020 to May 2022, Hookipa Pharma Inc., a biopharmaceutical company, from February 2019 to April 2023, and Chroma Medicine (which merged with Nvelop Therapeutics in December 2024 to form nChroma Bio, Inc.), a biotechnology company, from February 2023 to December 2024. Mr. Kelly has also held positions at Tanox, Inc., Biogen, Inc., and Nutrasweet Kelco Company, a division of Monsanto Life Sciences. He also serves on the Council of Advisors and was the former audit committee chairman for Direct Relief, a humanitarian aid organization focused on health outcomes and disaster relief. Mr. Kelly received his B.Sc. in Business Administration from Florida A&M University, concentrating in Finance and Industrial Relations.

Kaye Foster has served as a member of our Board since December 2021. Ms. Foster has been a Senior Advisor at the Boston Consulting Group since August 2014 and a Venture Partner at ARCH since January 2022. Previously, she was Senior Vice President, Global Human Resources at Onyx Pharmaceuticals, Inc., an Amgen, Inc. subsidiary and a biopharmaceutical company, from October 2010 to January 2014. At Onyx, she led all aspects of human resources for U.S. and global operations. Prior to joining Onyx, Ms. Foster was Global Vice President of Human Resources and an Executive Committee member at Johnson and Johnson Corporation, a healthcare company, from May 2003 to March 2010. Before Johnson and Johnson, Ms. Foster held several senior human resources executive positions with Pfizer Inc., a pharmaceuticals company. She currently serves on the board of directors and compensation committee of National Resilience Inc.; on the board of directors and the compensation and nominating and corporate governance committees of Agios Pharmaceuticals, Inc.; and on the board of trustees and the human resources committee of Spelman College. Ms. Foster previously served on the board of directors and real estate and nominations committees of Stanford Health Care, a hospital and healthcare system, and chaired the Glide Memorial Foundation Board of Trustees. She received her B.B.A. in Business Administration from Baruch College of the City University of New York and her M.B.A. from Columbia University, Graduate School of Business.

Wendy Chung, M.D., Ph.D. has served as a member of our Board since November 2021. Dr. Chung is an American Board of Medical Genetics certified clinical and molecular geneticist and serves as the Chair of the Department of Pediatrics at Boston Children's Hospital, a position she has held since July 2023. Previously, she led the Precision Medicine Resource in the Irving Institute at Columbia University from February 2014 to June 2023. Dr. Chung was on the faculty at Columbia University from 2002 to June 2023, most recently as the Kennedy Family Professor of Pediatrics and Medicine at Columbia University. Prior to that, she was an Associate Professor at Columbia University. Dr. Chung has served as a member of the board of directors of Rallybio Corporation, a public biotechnology company, since August 2022. She received her B.A. in Biochemistry from Cornell University, her M.D. from Cornell University Medical College, and her Ph.D. in Genetics from The Rockefeller University.

David Schenkein, M.D. has served as a member of our Board since September 2019. Dr. Schenkein currently serves as a partner in GV, the venture capital investment arm of Alphabet Inc., which he joined in February 2019. Previously, Dr. Schenkein served as President and Chief Executive Officer of Agios Pharmaceuticals, Inc. from August 2009 to February 2019. From April 2006 to July 2009, Dr. Schenkein served as a Senior Vice President of Oncology Development at Genentech Inc. Dr. Schenkein currently serves on the board of directors of Denali Therapeutics Inc. and Regeneron Pharmaceuticals, Inc. He is also on the boards of the private companies Leyden Laboratories B.V., Aera Therapeutics, Inc. and Treeline Biosciences, Inc. Previously, Dr. Schenkein served on the board of directors of Agios Pharmaceuticals, Inc. from 2009 to February 2025 and bluebird bio, Inc. from 2013 to 2021. He also currently serves as an adjunct attending physician in hematology at Tufts Medical Center. Dr. Schenkein received his M.D. from the State University of New York Upstate Medical School and his B.A. in Chemistry from Wesleyan University.

Thomas Cahill, M.D., Ph.D. has served as a member of our Board since November 2021. Dr. Cahill is the Founder and has served as the Managing Partner of Newpath Partners, a Boston-based life science venture fund focused on therapeutic companies, since October 2018. Dr. Cahill is the founding investor and director of nChroma Bio, Inc., Exo Therapeutics, Inc., Kisbee Therapeutics, Inc., Magnet Biomedicine, Inc., Myeloid Therapeutics, Inc., or Myeloid, Convergence Bio, Inc., Autobahn Therapeutics, Inc., Leal Therapeutics, Inc. and Amplitude Therapeutics, Inc. Prior to Newpath Partners, Dr. Cahill served as an Advisor at Raptor Group Holdings, where he helped further establish and lead the life science and technology investment portfolio, from September 2016 to May 2018. Dr. Cahill received both his M.D. and Ph.D. from Duke University and his M.S. from Stanford University.

Robert Nelsen has served as a member of our Board since September 2020. Mr. Nelsen co-founded ARCH Venture Partners, L.P., a venture capital firm focused on early-stage technology companies, in 1986 and has served as a Managing Director of ARCH Venture Partners or its affiliated entities since 1994. Mr. Nelsen currently serves on the board of directors of Sana Biotechnology, Inc. and Hua Medicine, Inc., each a public biotechnology company, and currently serves on the board of directors of a number of private companies. Mr. Nelsen previously served on the board of directors of a number of public biotechnology companies, including Vir Biotechnology, Inc., from 2017 to May 2025, Lyell Immunopharma, Inc. from 2018 to May 2025, Brii Biosciences Limited from 2019 to June 2024, Revolution Healthcare Acquisition Corp. from 2021 to April 2022, Denali Therapeutics Inc. from 2015 to June 2022, Beam from 2017 to June 2021, Karuna Therapeutics, Inc. from 2018 to June 2021, Unity Biotechnology, Inc. from 2015 to December 2020, Agios Pharmaceuticals, Inc. from 2007 to June 2017, Syros Pharmaceuticals, Inc. from 2012 to June 2018, Juno Therapeutics, Inc. (acquired by Celgene Corporation in January 2018), or Juno, from 2013 to March 2018, Sienna Biopharmaceuticals, Inc. from 2015 to September 2018 and Gossamer Bio, Inc. from 2017 to December 2018 (prior to its initial public offering). Mr. Nelsen received his M.B.A. from the University of Chicago and his B.S. from the University of Puget Sound in Economics and Biology.

On April 7, 2026, the Board of Directors of Prime Medicine, Inc. appointed Svetlana Makhni as the Chief Financial Officer and the principal financial officer of the Company effective as of April 16, 2026. Ms. Makhni, age 42, brings over 20 years of experience across multiple biotechnology and healthcare chief financial officer roles and investment banking. Prior to joining the Company, Ms. Makhni served as Chief Financial Officer of Marengo Therapeutics, Inc., a clinical-stage biotechnology company, from June 2022 to April 2026, as Chief Financial Officer of Escient Pharmaceuticals, Inc., a clinical-stage biotechnology company, from May 2021 to June 2022, and as Chief Financial Officer and Head of Operations at Bierman ABA, Inc., a behavioral health services provider, from October 2019 to May 2021. From 2006 through 2019, Ms. Makhni worked in investment banking and financial services at BMO Capital Markets, Goldman Sachs, Westbrook Partners and The Blackstone Group, where she advised public and private companies on equity and debt financings, mergers and acquisitions, and other strategic transactions. Ms. Makhni received her M.B.A. from Harvard Business School and her B.S. from the Wharton School of the University of Pennsylvania.

Carman Alenson, CPA, M.B.A. has served as our interim Chief Financial Officer and Chief Accounting Officer since September 2022 and has served as our Senior Vice President, Finance since January 2022. Ms. Alenson joined Prime Medicine in August 2021 as Vice President, Finance. Prior to that, she served as Vice President, Accounting, Treasury and Tax at Agios Pharmaceuticals, Inc., a biopharmaceutical company, from November 2016 to July 2021. Prior to that, from April 2015 to October 2016, she was Executive Director of Accounting, Controller, and Assistant Treasurer at AMAG Pharmaceuticals, Inc., a specialty pharmaceuticals company, where she managed the corporate accounting group. Ms. Alenson is a certified public accountant and received her M.B.A. and B.A. in Economics and Business Administration from Boston University. Effective January 17, 2024, Carman Alenson will transition from Interim Chief Financial Officer and Chief Accounting Officer to Senior Vice President, Finance and Chief Accounting Officer. She will step down from the role of principal financial officer and will continue in her role of principal accounting officer.