Steve Mahoney
President and Chief
Executive Officer
Steve Mahoney is Viridian’s President and Chief Executive Officer and a member of the Board of Directors. Steve has more than two decades of experience in a variety of operational, financial, commercial, legal and transactional roles in companies of different sizes and stages. He has been successful scaling organizations from founding team through commercial stage.
Prior to joining Viridian, Steve was the Chief Financial and Operating Officer of Magenta Therapeutics, where he drove operational excellence and disciplined capital allocation to high priority programs. Previously, Steve was part of the founding team of Kiniksa Pharmaceuticals, where he served as President and Chief Operating Officer. Prior to Kiniksa, he was Chief Commercial Officer of Synageva Biopharma, a company focused on ultrarare diseases, where he held roles of increasing responsibility in operations, commercial launch preparation, legal and corporate development. Steve was also a commercial attorney with Genzyme Corporation for approximately ten years. Prior to Genzyme, Steve was a corporate attorney with Mintz Levin.
He holds a Master’s in Business Administration (M.B.A) from Boston College’s Carroll School of Management, a Juris Doctor (J.D.) from Boston College Law School, and a Bachelor of Arts from Colorado College. He serves on the board of directors of Vesselon, Inc., a private company.
Thomas Ciulla, M.D.
Chief Medical Officer
Tom Ciulla was appointed Viridian’s Chief Medical Officer in January 2024 after previously serving as Viridian’s Chief Development Officer since 2023. Before joining Viridian, Dr. Ciulla served as Chief Medical Officer and Chief Development Officer at Clearside Bio, where he guided preclinical and clinical development, supported an NDA to first FDA approval of a suprachoroidal therapy, led an IND submission with development of a new clinical program and successful Phase 1/2 trial, and oversaw medical and professional affairs. Prior to Clearside, Dr. Ciulla served in a VP role as Medical Strategy Lead-Ophthalmology at Spark Therapeutics, where he defined and led medical strategy to support development and commercialization of the first FDA-approved gene therapy for a genetic disease. He previously served as VP, Clinical Strategy at Ophthotech Corporation.
Before launching his executive management career, Dr. Ciulla co-directed the retina service and ocular angiogenesis research lab at Indiana University School of Medicine, the largest U.S. medical school. He remains a volunteer Clinical Professor at the university and is a Fellow of the American Society of Retina Specialists, member of the American Society of Gene and Cell Therapy, Association for Research in Vision and Ophthalmology, Macula Society, Retina Society, and the American Academy of Ophthalmology.
Dr. Ciulla has held numerous leadership roles in clinical research, including principal investigator, medical monitor, and member of scientific advisory, data safety monitoring or writing committees in more than 100 national clinical trials. He has served on journal editorial boards, edited several textbooks, presented at more than 200 conferences, and co-authored more than 300 publications. Dr. Ciulla graduated from Harvard College and UCSF School of Medicine, followed by an internship and residency at Harvard Medical School and a fellowship at Tufts Medical School. He also earned an M.B.A. from Indiana University’s Kelley School of Business, specializing in the business of medicine.
Tom Beetham
Chief Operating Officer
Tom Beetham joined Viridian as Chief Operating Officer in October 2023. Tom has more than 20 years of experience in operations, business development, strategy and legal in the biopharmaceutical industry. Tom joined Viridian after serving as Chief Legal Officer of Magenta Therapeutics, Inc. Prior to Magenta, Tom served as Executive Vice President, Corporate Development and Operations, and Chief Legal Officer of Kiniksa Pharmaceuticals where he had reporting responsibility for multiple functions, including strategy, business development, technical operations, medical affairs, value and access, legal, compliance, quality and human resources. Prior to Kiniksa, Tom served as Senior Vice President, Chief Legal Officer and Corporate Development of Synageva BioPharma Corp. Prior to Synageva, Tom was General Legal Counsel for New England Biolabs, Inc., and earlier, was the lead corporate attorney for Genzyme Corporation’s Oncology and Multiple Sclerosis business units. Tom holds a Master’s in Business Administration (M.B.A) from Boston College’s Carroll School of Management, a Juris Doctor (J.D.) from Boston College Law School, and a Bachelor of Arts from the University of Rochester.
Jennifer Tousignant
Chief Legal Officer
Jennifer joined Viridian as Chief Legal Officer in February 2024. Jennifer has broad legal experience and leadership in the biotechnology industry working across a breadth of technologies such as small molecules, biologics, cell and gene therapies, and in the therapeutic categories of rare disease, immune-mediated disease, neurodegenerative disease, and oncology. Prior to Viridian, Jennifer served as Senior Vice President of Legal for Sana Biotechnology, Inc. where she was a leading a team responsible for legal support for strategic transactions, business development, intellectual property, litigation, quality, regulatory, research and development, investor relations, and general contracting as well as being involved in corporate governance and financings. She joined Sana from Xilio Therapeutics where she was the Head of Legal and responsible for all legal and compliance matters. Prior to Xilio, Jennifer was Chief IP Counsel at TESARO, Inc., where she built and led the intellectual property function, was a key member of the global launch teams for several products. Additionally, she played key legal roles in TESARO’s transactional work, financings, and in its acquisition by GSK. Before TESARO, she worked at Genzyme Corporation (acquired by Sanofi) in roles of increasing responsibility, first in research and then in legal, and ultimately leading a legal team with worldwide intellectual property responsibility for products from early research to commercial, including small molecules, biologics, and gene therapy products. During her time at Genzyme, Jennifer was a member of the global launch teams for several products and acted as a primary counsel supporting the business development teams of the rare disease and multiple sclerosis business units.
Jennifer received her JD from Suffolk University School of Law, magna cum laude, and her BA in Chemistry with Honors from the University of Virginia.
Shan Wu, Ph.D.
Chief Business Officer
Shan Wu joined Viridian in 2023 and serves as its Chief Business Officer. She brings extensive experience in the biopharmaceutical industry with a strong track record in business development, corporate strategy, communications, and operations.
Most recently, Shan served as Vice President and head of business development, investor relations, and alliance management at Magenta Therapeutics. She joined Magenta at launch and helped to build it from its scientific platform to a clinical-stage company. Shan led multiple value-creating transactions at Magenta, supported private and public financings including the company’s IPO, and helped to close Magenta’s merger with Dianthus Therapeutics. Prior to Magenta, Shan was at Biogen where she led strategic forecasting for the multiple sclerosis global commercial organization.
Previously, Shan was a management consultant at Clarion Healthcare where she led projects in therapeutic area strategy, product differentiation strategy, market opportunity assessment, and global launch planning for biopharma clients. Shan holds a Ph.D. in Biological Engineering from the Massachusetts Institute of Technology and a B.S. in Computer and Electrical Engineering from the University of Virginia.
Tony Casciano
Chief Commercial Officer
Tony was appointed as Chief Commercial Officer at Viridian in 2023 to establish and lead all functions and activities related to commercialization.
Tony joins having formerly served as the COO & CCO of AMAG Pharmaceuticals, where he oversaw all commercial activities, as well as technical operations, global supply chain, corporate planning, and information technology. During his 4 years at AMAG Tony led the turnaround of the hematology oncology franchise and several successful product launches in highly competitive specialty and orphan disease markets, including infused products and SC autoinjectors. Prior to AMAG, he spent 16 years leading various commercial functions with increasing levels of responsibility at Sanofi and Genzyme. Most recently, Tony was serving as CEO of an MIT medical device spinout, where he successfully led and closed a Series A financing.
He holds a bachelor’s degree in exercise science from Bridgewater State University and executive certificates in Marketing from the Wharton School of the University of Pennsylvania and in Governance from the Kellogg School of Management at Northwestern University.
Seth Harmon
Senior Vice President of Finance and Accounting
Seth is the Senior Vice President of Finance and Accounting and a member of the Executive Team at Viridian Therapeutics. He joined Viridian in 2023. Seth brings 20 years of strategic finance, accounting, and operations experience to his position. Prior to joining Viridian, Seth served as the CFO of BioNTech US, where he oversaw the general and administrative functions for BioNTech SE’s US subsidiary and served as a member of the BioNTech US management team supporting the growth of the organization from 56 to 500+ employees. Earlier in his career he served as Vice President of Finance at Neon Therapeutics where he contributed to the company’s successful $100M IPO and subsequently oversaw the financial aspects of the company’s restructure and strategic sales to BioNTech SE. Prior to Neon Therapeutics, Seth held several positions with increasing levels of responsibility at Merrimack Pharmaceuticals where he participated in the successful launch of company’s first commercial product and the subsequent sale of this asset to Ipsen.
Seth holds a BA in Economics and Mathematics from Bowdoin College, a M.S. in Accounting and M.B.A. from Northeastern University and obtained his certified public accountant license while working at Ernst and Young, LLP.
Tomas Kiselak
Managing Member, Fairmount Funds Management LLC
Tomas Kiselak is a Managing Member at Fairmount Funds Management LLC, a healthcare investment firm he co-founded in April 2016. Prior to Fairmount, Mr. Kiselak was a managing director at RA Capital Management, LLC. In addition to Viridian, Mr. Kiselak serves as a director for Apogee Therapeutics, Inc., Dianthus Therapeutics, Inc., Spyre Therapeutics, Inc., and several private companies. He received a bachelor’s degree in Neuroscience and Economics from Amherst College.
Arlene Morris
Chief Executive Officer, Willow Advisors
Arlene Morris currently serves as Chief Executive Officer at Willow Advisors, LLC, a consultancy advising biotech companies on financing, strategy and business development. Previously, she served as the President, Chief Executive Officer and a member of the board of directors of Syndax Pharmaceuticals, Inc, a privately held biotechnology company, and Affymax, Inc., a publicly traded biotechnology company. Ms. Morris has also held executive positions at Clearview Projects, Inc., Coulter Pharmaceutical, Inc., Scios Inc., Johnson & Johnson and board of director roles at Biodel Inc., and Dimension Therapeutics, Inc.
Arlene is currently a member of the board of directors of Viveve, Inc., Palatin Technologies, Inc., and Cogent Biosciences, Inc., and director emeritus for the Foundation for Research and Development at the Medical University of South Carolina where she served as Chair. She also serves as a trustee of Carlow University where she received a B.A. in Biology and Chemistry.
Jennifer Moses
Chief Financial Officer, Investors Management Corporation
Jennifer Moses is currently the Chief Financial Officer of Investors Management Corporation (IMC).
Prior to joining IMC, Ms. Moses served as Chief Financial Officer of G1 Therapeutics, Inc., a commercial-stage oncology company. Previously, Ms. Moses was a partner at Rankin McKenzie, LLC, where she served as acting chief financial officer and controller for venture-backed companies. Before joining Rankin McKenzie, Ms. Moses held roles of increasing responsibility at Deloitte, including providing tax services to clients and later focusing on strategic planning and internal communications in the Office of the CEO of Deloitte Tax. Ms. Moses also serves on the board of directors for Southern Trust Insurance Group, a privately held insurance company.
Ms. Moses received her B.S. in Accounting from The Pennsylvania State University and is a certified public accountant in the State of North Carolina.
Peter Harwin
Managing Member, Fairmount Funds Management LLC
Peter Harwin is a Managing Member at Fairmount Funds Management LLC, a healthcare investment firm he co-founded in April 2016. Prior to Fairmount, Mr. Harwin was a member of the investment team at Boxer Capital, LLC, part of the Tavistock Group, based in San Diego. Mr. Harwin also serves as chairman of the board of Cogent Biosciences, Inc. and is a director of Apogee Therapeutics, Inc., Spyre Therapeutics, Inc., and Paragon Therapeutics, Inc. Peter holds a Bachelor of Business Administration from Emory University.
Sarah Gheuens, M.D., Ph.D.
Chief Medical Officer, Head of R&D, Agios Pharmaceuticals
Dr. Gheuens joined Agios in December 2019, became chief medical officer in September 2021, and took on the additional role of head of R&D in August 2022. She has been instrumental in completing the pivotal Phase 3 program for pyruvate kinase deficiency and leading simultaneous regulatory submissions to the FDA and EMA in this indication, as well as designing the pivotal programs for thalassemia, sickle cell disease and the pediatric indications. Prior to joining Agios, Dr. Gheuens worked at Biogen, where she held roles of increasing responsibility in safety, medical affairs and clinical development. Her work was critical for the approval of SPINRAZA®. Before joining Biogen, Dr. Gheuens worked at Beth Israel Deaconess Medical Center (BIDMC), taking care of patients with HIV and neurological complications and doing research on progressive multifocal leukoencephalopathy. Dr. Gheuens received her medical degree from the Free University of Brussels (VUB), Belgium, and completed her neurology residency at the University Hospital of the Free University of Brussels, Belgium, followed by an HIV/neurology fellowship at BIDMC, Boston, Mass., USA. She also holds a Ph.D. in Medical Sciences from the University of Antwerp, Belgium, and a Master’s in Medical Sciences from Harvard Medical School.
Steve Mahoney
President and Chief
Executive Officer
Steve Mahoney is Viridian’s President and Chief Executive Officer and a member of the Board of Directors. Steve has more than two decades of experience in a variety of operational, financial, commercial, legal and transactional roles in companies of different sizes and stages. He has been successful scaling organizations from founding team through commercial stage.
Prior to joining Viridian, Steve was the Chief Financial and Operating Officer of Magenta Therapeutics, where he drove operational excellence and disciplined capital allocation to high priority programs. Previously, Steve was part of the founding team of Kiniksa Pharmaceuticals, where he served as President and Chief Operating Officer. Prior to Kiniksa, he was Chief Commercial Officer of Synageva Biopharma, a company focused on ultrarare diseases, where he held roles of increasing responsibility in operations, commercial launch preparation, legal and corporate development. Steve was also a commercial attorney with Genzyme Corporation for approximately ten years. Prior to Genzyme, Steve was a corporate attorney with Mintz Levin.
He holds a Master’s in Business Administration (M.B.A) from Boston College’s Carroll School of Management, a Juris Doctor (J.D.) from Boston College Law School, and a Bachelor of Arts from Colorado College. He serves on the board of directors of Vesselon, Inc., a private company.