Barry J. Simon, M.D., is a healthcare executive with more than 30 years of experience spanning the public and private sectors. Dr. Simon has been serving as a member of the Board of Directors since March 2021. Dr. Simon has served on the Board of Directors of ImmunityBio, Inc. (NASDAQ:IBRX) since June 2008 and as its Chief Corporate Affairs Officer since March 2021. Prior to that, Dr. Simon served as ImmunityBio’s President and Chief Administrative Officer since January 2017, President and Chief Operating Officer since March 2015 and as its President and Chief Executive Officer since May 2007. Dr. Simon has also served as Chairman, President and CEO of Brink Biologics, Inc., a bioanalytics, reagents and testing services company, since June 2015. He has served on the Board of Directors of Cue BioPharma, Inc. (NASDAQ:CUE), a biopharmaceutical company from March 2016 to June 2021 and as its Chairman from 2018 to 2021 and previously served on the Board of Viracta Subsidiary, Inc. (previously named Viracta Therapeutics, Inc.) from July 2017 to November 2020. Previously, Dr. Simon held Vice President, senior level and advisory positions at F. Hoffmann-La Roche (OTCQX:RHBBY), a global healthcare company, Roche Labs, a pharmaceuticals company, Connetics Corporation (NASDAQ:CNCT), a specialty pharmaceutical company, Immunomedics (NASDAQ:IMMU), a biopharmaceutical company, Immusol, a biopharmaceutical company, HealthPro BioVentures, LLC, a healthcare and life sciences investment bank and NorthSound Capital, LLC, a U.S.-based hedge fund. 

In his prior roles, Dr. Simon worked across several therapeutic areas including oncology, virology, ophthalmology and dermatology on product launches including Xeloda®, Pegasys®, Fortovase®, Tamiflu®, Boniva®, Fuzeon®, Valcyt®, Kytril® and Accutane®. Dr. Simon attended corporate training programs by the London School of Business and the Amos Tuck School of Business at Dartmouth College. He received his M.D. from the SUNY Downstate Health Sciences Center in New York and trained clinically in infectious diseases, anesthesiology, and internal medicine at Albert Einstein College of Medicine, The Mount Sinai Medical Center and New York University, respectively.

Ivor Royston, M.D., served as Viracta’s founding President and CEO from 2015 until September 2022. From 1990 to 2017, Dr. Royston was a Managing Partner of Forward Ventures, a life science venture capital firm. From 1990 to 2000, Dr. Royston also held the position of Chief Executive Officer of the Sidney Kimmel Cancer Center. Prior to that, Dr. Royston was the Director of Clinical Immunology at University of California, San Diego Cancer Center. Dr. Royston was the co-founder of Hybritech, Inc., which developed the PSA test for prostate cancer; and the co-founder of IDEC Corporation, which developed Rituxan, the first approved monoclonal antibody therapy for lymphoma, and which subsequently merged with Biogen to form Biogen Idec, now Biogen. Dr. Royston currently serves on the board of directors of Biocept, Inc. (NASDAQ:BIOC). Dr. Royston received his B.A. and M.D. degrees from Johns Hopkins University and completed post-doctoral training in internal medicine and medical oncology at Stanford University.

Mark Rothera joined Viracta as President, Chief Executive Officer and Director in September 2022. Mr. Rothera brings more than 30 years of experience in the biopharmaceutical industry, with a strong record of commercial and global leadership, including driving the successful build of multiple biotech companies, predominantly in the field of rare or specialty diseases. Prior to joining Viracta, Mr. Rothera served as President and CEO of Silence Therapeutics (NASDAQ: SLN), a clinical-stage organization focused on developing RNA therapies for hematology, cardiovascular and rare diseases. He previously served as CEO of Orchard Therapeutics (NASDAQ: ORTX), where he oversaw its transformation from a small U.K.-based, privately held company with two clinical-stage programs into a leading gene therapy company with seven clinical-stage programs and fully integrated capabilities. During his tenure, Orchard Therapeutics secured more than $600 million in financing and grew from a market capitalization of $250 million to more than $1.7 billion at its peak. Prior to Orchard, Mr. Rothera served as Chief Commercial Officer of PTC Therapeutics (NASDAQ: PTCT), where he helped it evolve into a commercial company with a global footprint, including the successful launch of two rare disease therapies. Previously, he served as Global President of Aegerion Pharmaceuticals Inc. and Vice President and General Manager of commercial operations at Shire Human Genetic Therapies for Europe, Middle East and Africa. Mr. Rothera currently serves on the Board of Directors at GenPharm. He received an M.A. in Natural Sciences from Cambridge University and an M.B.A. from the European Institute for Business Administration (INSEAD).

Mr. Darcy previously was a cofounder and director of Tocagen Inc. from August 2007 until June 2020. Mr. Darcy also served as Tocagen Inc.’s Chief Financial Officer from August 2007 to February 2017 and as Tocagen’s Executive Vice President from August 2007 to May 2017. Prior to Tocagen, Mr. Darcy served for over five years as Executive Vice President and Chief Financial Officer of Science Applications International Corporation (“SAIC”), a Fortune 500 science and technology company. Mr. Darcy also served as a director and chairman of the audit committee of McAfee, Inc., a publicly-held technology company, for over three years until its sale to Intel Corporation in February 2011. Mr. Darcy also served as a director and audit committee member of Forte Biosciences, Inc. from June 2020 through May 2021 and currently serves as a director and chairman of the audit committee of Lytx, Inc., a privately-held technology company. Prior to SAIC, he was an audit Partner in the accounting firm of PricewaterhouseCoopers LLP, where he served as the Managing Partner of both the West and Southwest Region Audit and Business Advisory Service Technology practices, as well as the Managing Partner of the San Diego office. Mr. Darcy is a Certified Public Accountant (inactive) in the state of California and graduated from San Diego State University with a B.S. in Accounting.

Flavia Borellini, Ph.D., has more than 25 years of executive management experience in the pharmaceutical and biotechnology industry, with a particular focus on global development of targeted oncology drugs, from preclinical to commercial stage. She is the former Chief Executive Officer for Acerta Pharma, where she oversaw the successful development and approval of Calquence^® (acalabrutinib), a selective Bruton’s tyrosine kinase (BTK) inhibitor, for the treatment of mantle cell lymphoma and chronic lymphocytic leukemia (CLL). During her career, Dr. Borellini has also held key senior level positions within AstraZeneca, most recently Global Franchise Head, Hematology, with responsibility for the hematology portfolio in the company’s oncology business unit. While at AstraZeneca, she led the global development, approval, and commercialization of Tagrisso^® (osimertinib), a first-in-class epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor for the treatment of non-small cell lung cancer (NSCLC) caused by the T790M mutation.

Prior to her tenure with AstraZeneca, Dr. Borellini spent nearly seven years at Genentech, a member of the Roche Group. During this time, she led the global development, approval and launch of Zelboraf^® (vemurafenib), a first-in-class BRAF inhibitor for the treatment of melanoma caused by the V600E BRAF mutation. Dr. Borellini also served as the program leader for Herceptin^® (trastuzumab), a targeted treatment for HER2 receptor positive cancers, including breast cancer, and Tarceva^® (erlotinib), an EGFR tyrosine kinase inhibitor for the treatment of NSCLC and pancreatic cancer. Dr. Borellini obtained a Ph.D. in Pharmaceutical Chemistry and Technology from the University of Modena in 1984.

Dr. Borellini also serves on the Board of Directors of Kartos Therapeutics, Cantargia AP, and Revolution Medicines.

Dr. Pomerantz has served as a member of the board of directors of Viracta since June 2020 and was appointed Chair in September 2020. Dr. Pomerantz served as President, Chief Executive Officer and Chairman of the Board of ContraFect Corporation (NASDAQ: CFRX) from April 2019 – November 2023. Previously, Dr. Pomerantz was a Venture Partner at Flagship Pioneering from 2014 through 2019. In addition, he served as the President, Chief Executive Officer and Chairman of the Board of Seres Therapeutics from 2014-2019, where he continues to serve as Senior Advisor to its Board of Directors. Previously, Dr. Pomerantz was Senior Vice President, Worldwide Head of Licensing & Acquisition at Merck & Co., Inc and prior to that was Senior Vice President and Global Franchise Head of Infectious Diseases at Merck. Prior to joining Merck, Dr. Pomerantz was Global Head of Infectious Diseases for Johnson & Johnson Pharmaceuticals. He also served as Chief Executive Officer of Tibotec Pharmaceuticals, Inc. Dr. Pomerantz currently serves on the boards of Intec Pharma Ltd. (NASDAQ: NTEC).

Dr. Pomerantz received his B.A. in Biochemistry at the Johns Hopkins University and his M.D. at the Johns Hopkins School of Medicine. He received post-graduate training at the Massachusetts General Hospital, Harvard Medical School and M.I.T. Dr. Pomerantz is Board Certified in both internal medicine and infectious diseases. He was Professor of Medicine, Biochemistry and Molecular Pharmacology, Chief of Infectious Diseases, and the Founding Director and Chair of the Institute for Human Virology and Biodefense at the Thomas Jefferson University and Medical School.