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Overview Line Executive Management Line Scientific Advisory Board Line Business Advisory Board Line Contact

Executive Management

David J. Bearss

David J. Bearss, Ph.D.

Chief Executive Officer
Dr. David J. Bearss, Ph.D., brings a consistent and successful track record of drug discovery and development that spans the last 17 years in both academic and industrial settings. Dr. Bearss is an expert in small-molecule drug development and in the use of genetic model systems in drug discovery and has deep experience in translational research focused on drug development and the use of genetic markers to predict drug sensitivity. He is also an expert in the development and use of genetically modified animals to model human disease. Dr. Bearss received his Ph.D. in Cell and Structural Biology at the University of Texas Health Sciences Center at San Antonio and was a post-doctoral fellow with Dr. Daniel Von Hoff, a recognized leader in drug development. Dr. Bearss was on faculty at the University of Arizona from 1999-2003 after-which he co-founded Montigen Pharmaceuticals in 2003 where he served as Chief Scientific Officer until Montigen was acquired by SuperGen (Nasdaq: SUPG) in 2006. Dr. Bearss served as Chief Scientific Officer at SuperGen overseeing early drug discovery and development and subsequently as Co-director of the Center for Investigational Therapeutics at the Huntsman Cancer Institute, Associate Professor in the Department of Oncological Sciences at the University of Utah and Associate Professor of Physiology & Developmental Biology at Brigham Young University prior to co-founding Tolero. Dr. Bearss has published more than 70 manuscripts and book chapters, has over 30 patents issued or pending and has won several awards for his scientific achievements.

David W. Sampson

David W. Sampson

Chief Financial Officer
David Sampson has extensive experience working with both small to medium size companies in rapidly growing environments and also with large publicly traded companies. Before joining Tolero, Mr. Sampson served as the Vice President of Finance and Principal Accounting officer of Fusion-io, Inc., during a period of rapid growth—including sales growth from $36 million to over $400 million, the company's initial public offering, and its expansion internationally - prior to the ultimate acquisition by SanDisk Corporation for a value exceeding $1 billion in market capitalization. Prior to Fusion-io, Mr. Sampson was Vice President of Finance for Ancestry.com, Inc. where he oversaw all financial and accounting, treasury and credit card processing aspects of the company and was instrumental in the company’s international expansion, acquisitions and initial public offering. Mr. Sampson also spent twelve years of his career at Ernst and Young in Palo Alto, California and Salt Lake City, Utah where he assisted small entrepreneurial to large multinational companies with technical accounting issues, debt financing arrangements, initial public offerings, and compliance with SEC filing requirements. Mr. Sampson is a Certified Public Accountant in the state of California and Utah and has a Bachelor of Science degree in accounting from Brigham Young University.

Steve Weitman, M.D., Ph.D.

Steven D. Weitman, M.D., Ph.D.

Chief Medical Officer
Dr. Weitman is the director of the Institute for Drug Development at the CTRC. Prior to joining the IDD in 2011, he was a full-time consultant to academic organizations and industry focused on bringing new anticancer therapies to patients. Dr. Weitman also served as chief medical officer and senior vice president at ILEX Oncology. He is a pediatric oncologist who works on the development of new therapies for both adult and pediatric patients. In returning to the Health Science Center, where from 1996 to 2001 he was a program director within the IDD, his goal is to create and support oncology drug development, build experimental clinical (phase I and phase II) programs and develop individualized patient cancer treatment initiatives involving both laboratory and clinical teams.

Michael V. McCullar, PhD

Michael V. McCullar, Ph.D.

Chief Operating Officer
Dr. Michael V. McCullar serves as the Chief Operating Officer for Tolero Pharmaceuticals. Most recently, Dr. McCullar served as Senior Vice President of Business Development of Astex Pharmaceuticals, which was acquired by Otsuka Pharmaceuticals for $880 million in cash. Dr. McCullar held other senior positions within Astex Pharmaceuticals and predecessor organizations including Senior Vice President of Strategy and Operations where he led SuperGen's acquisition of Astex Therapeutics as well as the acquisition of Montigen Pharmaceuticals. Dr. McCullar held the position of VP of Strategy and Development and led the approval of Dacogen in MDS and held operating responsibility for SuperGen’s European commercial business. Dr. McCullar has been involved with several ANDAs as well as INDs and held management positions in Drug Discovery, Regulatory Affairs and CMC. Dr. McCullar served on the Board of Trustees for the Leukemia and Lymphoma Society. Dr. McCullar holds a Ph.D. in Toxicology from the University of California, Riverside as well as an M.B.A. from the W.P. Carey School of Business at the Arizona State University, Tempe.

Steven L. Warner

Steven L. Warner, Ph.D.

Vice President, Drug Discovery and Development
Steven Warner, Ph.D., specializes in small molecule drug discovery, new screening platforms in drug discovery, and translational research focusing on cancer therapeutics. He is an expert in the discovery of novel cancer agents and has played integral roles in moving multiple compounds into clinical trials. Dr. Warner has a broad background in molecular and cell biology that comes from nearly a decade of involvement in drug discovery and development in both academic and pharmaceutical industry settings. Dr. Warner earned his graduate degree in Pharmaceutical Sciences at the University of Arizona. He completed a postdoctoral fellowship under the mentoring of Dan Von Hoff at the Translational Genomics Research Institute (TGen). In 2007, Dr. Warner joined SuperGen Inc. where he led a team of scientists focusing on studies ranging from initial compound library screens to proof-of-concept studies in animal models. Most recently, Dr. Warner has worked with the Center for Investigational Therapeutics at the Huntsman Cancer Institute as Senior Manager, Drug Discovery. Together in these capacities, he has led or integrally participated in drug discovery projects that have produced three first-in-man clinical compounds and has published several peer-reviewed publications and patents from multiple drug discovery projects.

Mike Bernstein, M.P.H.

Michael A. Bernstein, M.P.H.

Vice President, Regulatory Affairs
Over 28 years professional experience in the Pharmaceutical/Biotech/Device industry encompassing the areas of clinical and regulatory strategy, quality assurance and CMC strategy with experience in oncology, neurology, psychopharmacology, dermatology and wound care as well as other indications. Mike spent 11 years at FDA and has extensive experience working with regulatory agencies around the world. Mike has submitted over 20 INDs/CTXs and has submitted 9 NDAs/BLAs/MAAs and have received approval for 5 NDAs/ BLAs /MAAs He has also submitted 6 510(k)s and received clearance on all of them. Mike currently resides in San Antonio, Texas and was a former employee of Ilex Oncology, a Texas-based pharmaceutical company started by Dr. Dan Von Hoff.

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