About Us: Board of Directors

Perry Karsen, Board Chair

Perry Karsen brings decades of proven executive leadership and board experience to the Board of Directors at Graphite Bio. Mr. Karsen served as the chief executive officer of the Celgene Cellular Therapeutics division of Celgene Corporation and as Executive Vice President and Chief Operations Officer of Celgene Corporation. Previously, he was president and CEO of Pearl Therapeutics, Inc., a privately held biotechnology company subsequently acquired by AstraZeneca plc. He also has held executive positions at Human Genome Sciences, Inc., a biopharmaceutical company subsequently acquired by GlaxoSmithKline, Bristol-Myers Squibb Co., Genentech, Inc., and Abbott Laboratories. Currently, Mr. Karsen is board chair of Jounce Therapeutics, executive chair of Nitrome Biosciences and on the board of ESCAPE Bio. Mr. Karsen has also served on the Board of Intellia Therapeutics through 2020. He also serves on the Gladstone Foundation Board. In 2019, Mr. Karsen was appointed as a fellow in the Stanford University Distinguished Careers Institute.


Abe Bassan

Abe Bassan has extensive experience in the gene therapy arena as an operator and investor. He currently is a Vice President at Samsara BioCapital. Mr. Bassan previously served as director of program biology at Revolution Medicines, where he co-led the initial stages of the company’s 4EBP1/mTORC1 cancer program. Prior to that, he was associate director of program development at bluebird bio, where he was the project manager for the company’s β-Thalassemia, Sickle Cell Anemia, and ALD gene therapy programs. Earlier in his career, Mr. Bassan was an associate at Third Rock Ventures, where he played a leading role in the firm’s investment in bluebird bio, as well as the ideation of Blueprint Medicines, a precision medicine oncology company. Mr. Bassan was also the founder of Aurora Medical, a molecular diagnostics testing services company.

Jerel Davis, Ph.D.

Dr. Jerel Davis brings a distinguished track record as an investor and advisor to his role as a board member of Graphite Bio, with proven expertise in company creation, R&D alliances, and corporate partnerships. He currently serves as managing director of Versant Ventures. During his nine year tenure at Versant, Dr. Davis has helped propel the growth strategies of a multitude of the firm’s portfolio companies including BlueRock Therapeutics, Crispr Therapeutics, Repare Therapeutics, Chinook Therapeutics, Tentarix Biotherapeutics, Turnstone Biologics, Ventus Therapeutics, and several others. Prior to joining Versant, Dr. Davis was an associate principal at McKinsey & Company, where he advised a broad range of pharmaceutical, biotechnology, medical device, and molecular diagnostics companies. He has worked in a number of healthcare markets globally including the U.S., Canada, Europe, China, Russia, and India.


Kristen M. Hege, M.D.

Dr. Kristen Hege is a renowned physician scientist and a pioneer in advancing cell therapies through clinical development to regulatory approval. She currently serves as senior vice president, early clinical development, hematology/oncology and cell therapy at Bristol Myers Squibb (BMS) where her team is responsible for advancing the pipeline from first-in-human studies to clinical proof-of-concept. Notably, Dr. Hege led the development of Abecma (idecabtagene vicleucel; ide-cel), the first BCMA-directed CAR T cell immunotherapy for the treatment of adult patients with relapsed or refractory multiple myeloma from product concept to approval in partnership with bluebird bio. Prior to BMS, Dr. Hege held multiple executive roles at several biotech companies, including Celgene, Cell Genesys, Cellerant Therapeutics, and Theraclone Sciences. Dr. Hege, a hematologist-oncologist, is also a Clinical Professor of Medicine at the University of California (UCSF), San Francisco, where she continues to manage patients with benign and malignant blood disorders. Dr. Hege also serves on the Board of Directors of Mersana Therapeutics and was elected to the Board of Directors for the Society for Immunotherapy of Cancer (SITC) for a three-year term from 2016-2019.


Joe Jimenez

Joe Jimenez is the former chief executive officer of Novartis, one of the world’s leading pharmaceutical companies. Mr. Jimenez joined Novartis in 2007 to lead the pharmaceuticals division and was named CEO in 2010. He navigated the company through a period of change following patent expirations of its two largest products. Under his stewardship, Novartis developed one of the largest pipelines of self-originated drugs in the industry, driven by a strong commitment to research and development.Currently, Mr. Jimenez is co-founder and managing director of Aditum Bio, an investment firm focused on developing biotechnology assets that will benefit patients. He also serves as a board member of General Motors Company and The Proctor & Gamble Company.

Josh Lehrer, M.Phil., M.D., FACC

Dr. Josh Lehrer is the chief executive officer at Graphite Bio. In this role, Dr. Lehrer bridges his clinical background as a practicing physician with decades of experience at global biopharmaceutical companies leading businesses and high-functioning teams across all stages of drug development. Previously,              Dr. Lehrer served as chief medical officer at Global Blood Therapeutics (GBT) where he led the innovative clinical development strategy for sickle cell disease treatment Voxelotor from pre-IND stages through approval and commercial launch, including playing an integral role in raising over $1 billion to fund the product’s development and launch.Dr. Lehrer has also served in leadership roles at Genentech in clinical development and business development, as well as attending physician roles at Stanford University Medical Center and the Palo Alto Veteran’s Affairs Health System.

Matthew Porteus, M.D., Ph.D.

Dr. Matthew Porteus is an academic founder of Graphite Bio and a pioneer in the field of gene editing. Currently, he is a Professor of Pediatrics and Stem Cell Transplantation and the Co-Director of Center for Definitive and Curative Medicine at Stanford University. His work in gene editing spans more than two decades, during which he was an academic founder of CRISPR Therapeutics, and an advisor to several other gene editing companies, as well as the National Heart, Lung, and Blood Institute on Sickle Cell Disease. As a trained Pediatric Hematologist, Dr. Porteus now cares for children who are on the Pediatric Stem Cell Transplant service.

Carlo Rizzuto, Ph.D.

Dr. Carlo Rizzuto is a seasoned biopharmaceutical business executive and investor with over two decades of diverse leadership experience. He currently is a partner at Versant Ventures based in New York, and has played an instrumental role in launching and growing multiple companies including Pandion Therapeutics, Repare Therapeutics, Century Therapeutics, and Jnana Therapeutics, among others. Earlier in his career, he led global product development teams at Novartis AG and was an associate principal with McKinsey & Company, advising U.S. and European clients in the pharmaceutical, payor and provider sectors.

Smital Shah

Smital Shah brings proven executive leadership expertise to her role as a board member of Graphite Bio, including over two decades of senior management experience in the biopharma and investment banking industries. She currently serves as chief business and financial officer of ProQR Therapeutics, a biotechnology company focused on rare genetic diseases. Previously, Ms. Shah managed the multi-billion-dollar debt, cash and investment portfolios of Gilead Sciences. Her proven management and leadership experience in the biopharma industry is augmented by her earlier career in investment banking, where she has particular expertise in financial strategy, capital markets and business development. Prior to Gilead, Ms. Shah spent several years in investment banking at Leerink Partners and J.P. Morgan focused on the biotech sector. Earlier in her career, she held various research and development positions at Johnson & Johnson. Ms. Shah is a board member and chair of the audit committee at Pliant Therapeutics.

Jo Viney, Ph.D.

Dr. Jo Viney brings a distinguished track record in drug discovery and development to the Board of Directors at Graphite Bio. She currently serves as president, chief scientific officer and co-founder of Pandion Therapeutics, now a wholly-owned subsidiary of Merck & Co., Inc. Prior to founding Pandion, Dr. Viney served most recently as senior vice president, drug discovery at Biogen. Throughout her career, Dr. Viney has been an advocate for workplace inclusiveness. From 2015 – 2020, she served on the Board of WEST, a non-profit organization supporting early to mid-career women, and was WEST’s President for the 2017-2018 term. Dr. Viney has maintained longstanding memberships with the Society for Mucosal Immunology (SMI) and American Association of Immunologists (AAI). She has served numerous terms on the SMI Board and was president from 2011-2013. In 2020, Dr. Viney was chosen as one of FiercePharma’s Fiercest Women in Life Sciences. Dr. Viney is also a member of the board of directors for Finch Therapeutics and Harpoon Therapeutics, and she serves on the Scientific Advisory Board for HotSpot Therapeutics.