Gideon E. Bollag, Ph.D.
Chief Executive Officer

Gideon E. Bollag, Ph.D.Dr. Bollag has served as chief executive officer since May 2013, and has more than 23 years of biotechnology drug discovery experience.  More recently, he was the senior vice president of research since June 2008.  Prior, he served as vice president of discovery biology since November 2004. He joined Plexxikon as senior director of drug discovery in June 2002. Dr. Bollag was instrumental in the discovery and development of Zelboraf®, Plexxikon’s first oncology drug now approved in the U.S. and many other countries, along with its companion diagnostic.  Prior to Plexxikon, he helped build drug discovery capabilities at Syrrx, Inc., where he was the director of cellular pharmacology.  Before Syrrx, he held escalating positions at Onyx Pharmaceuticals, initially as one of the founding scientists and eventually senior director of small molecule therapeutics.  While there, Dr. Bollag was involved in the Onyx collaboration with Bayer to discover BAY 43-9006 (Nexavar), now an approved cancer treatment.  Prior to Onyx, Dr. Bollag held various scientific positions at Cetus, Inc. Dr. Bollag earned his Ph.D. in biochemistry from the University of California, Berkeley.

Paul Lin, M.D., M.B.A.
Chief Operating Officer

Paul Lin, M.D., M.B.A.Dr. Lin has served as chief operating officer of Plexxikon since May 2013 and has over 17 years of life sciences and technology industry experience.  He joined Plexxikon in 2005 and has held positions of increasing responsibility in business development and operations management.  Dr. Lin led much of the IND filing effort for vemurafenib/Zelboraf® and was a principal contributor to the drug’s early development.  He was part of Plexxikon’s deal team responsible for three licensing deals valued collectively at over $2 billion.  Prior to Plexxikon, Dr. Lin was an assistant to the CEO of Dendreon Corporation and served as a consultant to multiple pharmaceutical, biotech and medical device companies including Medtronic, Othera Pharmaceuticals and Acuity Pharmaceuticals.  Dr. Lin was also formerly Vice President of Business Development for eTechtransfer, a biotechnology licensing and marketplace start-up that he co-founded.  Previously, Dr. Lin was an operations engineer managing large scale manufacturing operations across multiple industries for BASF AG and Shell Oil Company.  Dr. Lin received dual M.D. and M.B.A. degrees from the University of Pennsylvania School of Medicine and the Wharton School of Business.  Before graduate school, he earned a B.S.E. in Chemical Engineering from the University of Michigan – Ann Arbor, where he graduated summa cum laude.

Henry Hsu, M.D.
Chief Medical Officer

Henry Hsu, M.D.Dr. Hsu has served as chief medical officer since May 2013.  He brings extensive experience building and leading clinical research groups, and managing drug development programs from first-in-human to NDA approval across multiple therapeutic areas. Dr. Hsu was most recently the chief executive officer, co-founder and chief medical officer of Altheos, Inc., where he helped raise over $32 million, led business development negotiations and advanced the company’s lead compound to the clinic.  Prior to that,   Dr. Hsu served as chief medical officer of Molecular Partners and as senior clinical advisor to Index Ventures.  He has also held various chief medical officer and clinical research positions of increasing responsibility at CoMentis, Co-Therix, Intermune and Chiron.  Dr. Hsu received his medical degree from the University of California, San Francisco, and completed his residency at the University of California, Davis in internal medicine, where he also served as Chief Medical Resident.  He subsequently completed a fellowship in gastroenterology/hepatology and a post-doctorate research fellowship at Stanford University Medical Center.

Chao Zhang, Ph.D.
Senior Vice President, Research

Chao Zhang, Ph.D.Dr. Zhang has served as Plexxikon’s senior vice president of research since November 2015 and has more than 13 years of pharmaceutical discovery experience.  He joined Plexxikon in 2001 as associate director of bioinformatics and became director of informatics in 2004, leading the company’s efforts in both computational chemistry and computational biology.  Dr. Zhang assumed additional responsibilities in 2008 when the structural biology and informatics teams were merged to strengthen the company’s core expertise in structure-guided drug design.  Dr. Zhang helped build the scaffold-based drug discovery platform at Plexxikon, and has been a leader and key contributor to the company’s wealth of discovery efforts.  Dr. Zhang was instrumental in the discovery of Zelboraf®, Plexxikon’s first oncology drug now approved in the U.S. and many other countries.  Prior to Plexxikon, Dr. Zhang was a scientist at Incyte Genomics where he developed an integrated genomics information system for mining disease-related genes and novel drug targets.  Dr. Zhang earned his Ph.D. in biomedical engineering from Boston University, and was a postdoctoral fellow at the University of California at Berkeley.

Sandra E. Tong, M.D.
Vice President, Clinical Research

Chao Zhang, Ph.D.Dr. Tong has served as Vice President of Clinical Research since December 2013, bringing over 15 years of experience in drug development in immunology, inflammation, oncology, auto-immune diseases, anemia and nephrology.  She has extensive experience in translational medicine, having managed numerous clinical programs from Phase 1 through Phase 3 and successful NDA approval.  Before joining Plexxikon, Dr. Tong served as senior director of clinical development for Affymax, where she was the clinical lead for Phase 3 studies for anemia.  Prior to that, she was a senior director of clinical research for Alza Corporation and the interim head of clinical operations at Scios, Inc.  She began her biotech career at Roche Bioscience, where she was the director of clinical research in the Inflammatory Diseases unit.  Dr. Tong is also a volunteer Assistant Clinical Professor of Medicine at the VA Medical Center in San Francisco.  She received her M.D. from the Johns Hopkins University School of Medicine, and has been board certified in rheumatology and internal medicine. 

Joseph Young, M.B.A.
Vice President, Finance and Corporate Development

Joseph Young, M.B.A.Mr. Young has served as vice president of finance and corporate development since April 2014, and as treasurer of Plexxikon, since May 2013.  He joined Plexxikon in 2006, initially as controller.  Prior to Plexxikon, Mr. Young held a senior finance position with VaxGen, Inc.  During 1999 to 2005, Mr. Young was a member of the management team of Cerus Corporation, a publicly-traded biotechnology company, most recently as controller where he managed the company's accounting, SEC reporting and budgeting functions, participated in financing transactions raising over $310 million and led Cerus' Sarbanes-Oxley compliance projects.  Mr. Young was a member of the audit staff of Ernst & Young LLP during 1994 to 1999.  Mr. Young received his M.B.A. from the Haas School of Business at the University of California, Berkeley, and is a certified public accountant (inactive status).