Executive Management

Geoff Hamilton

Co-Founder, Chief Executive Officer

Geoff Hamilton is co-founder and Chief Executive Officer of Stemson Therapeutics.  He brings 20 years of product commercialization and business executive experience with the last 15 years spent in life science and biotech companies.  Prior to founding Stemson Therapeutics, Geoff spent five years at Illumina, a Fortune 500 company and world leader in DNA sequencing technology, where he held leadership positions in marketing, product management, and strategic partnerships.  During his time at Illumina, Geoff launched three instrument platforms and helped the company grow from $1.4B to $3.8B in annual sales.  Prior to Illumina, Geoff spent ten years at Life Technologies (now a part of ThermoFisher Scientific) where he held various leadership roles in marketing, global commercial operations, and acquisition integration.  He helped build the company from $1.2B to $3.6B in annual sales before the ThermoFisher Scientific acquisition.  Geoff earned a Bachelor of Science in Business Administration from the University of North Carolina, Chapel Hill.

Alexey Terskikh, PhD

Co-Founder, Chief Scientific Officer

Alexey V. Terskikh, PhD, is co-founder and Chief Scientific Officer of Stemson Therapeutics. He developed the technology upon which Stemson Therapeutics was founded. Dr. Terskikh is also an Associate Professor at the Sanford Burnham Prebys Medical Discovery Institute (SBP). He joined SBP in 2006 focusing his research on molecular mechanisms underlying self-renewal and differentiation of neural stem cells. This work led to the discovery of the process which converts human induced pluripotent stem cells into dermal papilla cells, the specialized cells which control hair growth. Prior to joining SBP, Dr. Terskikh completed his postdoctoral training at Stanford University with Professor Irving Weissman. Dr. Terskikh earned his PhD in molecular immunology at the University of Lausanne (Switzerland) with Professor Jean-Pierre Mach.

Matt Posard

Executive Chairman

Mr. Posard brings over 30 years experience of general management and commercialization experience in the biotechnology industry.   Matt’s expertise is introducing novel and transformational products to medical and research markets while scaling organizations efficiently.    Matt has held executive title responsibilities with several highly successful growth companies including Illumina, Biosite and Gen-Probe.    From 2006 to 2015, Matt held executive positions at Illumina as its VP of Marketing, VP Global Sales and then as Senior VP, General Manager of its Translational and Consumer Genomics and New and Emerging Markets business units.   Matt currently serves on multiple boards including Halozyme Therapeutics (NASDAQ: HALO), Dermtech, Talis Biomedical, Ignite Bio, and Fabric Genomics.   Matt holds a Bachelors degree in Management Science from UC San Diego.

Cenk Sumen, PhD

Chief Technology Officer

Cenk Sumen, PhD, is Chief Technology Officer of Stemson Therapeutics and member of the Board of Directors.  He is a globally recognized expert in gene and cell therapy manufacturing and automation, and he brings over a decade of experience in the biotech and biopharmaceutical industries. He has worked closely with many of the pioneering cell therapy developers to support strategic consulting and clinical manufacturing while serving as a technical and business development leader at PCT, helping position this key boutique CDMO for acquisition by Hitachi Chemical. Prior to joining Stemson, Cenk served as the Director of Business Development for the BioProduction Division at ThermoFisher Scientific, where he was responsible for identifying and developing novel biopharmaceutical manufacturing technologies, setting up several key innovation partnerships.  He currently serves in the Outreach & Communication (former Chair) and Publication Committees for the American Society of Gene & Cell Therapy. Cenk earned his BS in Biology at MIT and his PhD in Microbiology & Immunology at Stanford University, completing post-doctoral studies in cancer immunology at Harvard Medical School and Memorial Sloan-Kettering Cancer Center.

Scientific & Medical Advisory Board

Hideyuki Okano, MD, PhD

Hideyuki Okano received his M.D. in Physiology from Keio University in 1983. After he obtained a Ph.D. degree in Molecular Biology of Myelin-related genes and myelin deficient mutant mice from Keio University in 1988, he held a post-doctoral position at Dr. Craig Montell’s Lab in Johns Hopkins University School of Medicine. He was appointed full professor at Tsukuba University School of Medicine in 1994, Osaka University School of Medicine in 1997, and returned to Keio University Medical School in 2001 as a full professor of Physiology. Since 2007 to date, he has served as Dean of Keio University Graduate School of Medicine and Dean of Keio University School of Medicine. He has been conducting basic research in the field of regenerative medicine including, neural stem cells and iPS cells, spinal cord injury, developmental genetics and RNA binding proteins. He has earned many awards and honors including the Medal with Purple Ribbon in 2009 and the first prize of the 51st Erwin von Bälz Prize in 2014. He aims to establish and provide patients-specific iPS cells and genetically modified non-human primate models for neuroscience research and to explore the pathogenic mechanisms of neurological/psychiatric disorders. Currently, he is the leader of Brain Project in Japan (Brain/MINDS) and a Vice President of Japanese Society for Regenerative Medicine.

Michael Rendl, MD

Dr. Rendl is a stem cell biologist, Associate Professor, and Principal Investigator at the Black Family Stem Cell Institute (BFSCI), Department of Cell, Developmental and Regenerative Biology (CDRB) and Department of Dermatology at Icahn School of Medicine at Mount Sinai (ISMMS).  His research focuses on the formation and function of stem cell niches with a particular emphasis on hair follicle formation. Utilizing genetic mouse models for embryonic hair follicle formation and for adult hair growth and regeneration he seeks to uncover how specialized Dermal Papilla (DP) cells act as instructive niche cells for hair follicle stem cells.  He hopes insights from his studies will provide a platform for developing hair regenerative therapies.  Dr. Rendl obtained his MD from Medical University of Vienna and completed a postdoctoral fellowship in Elaine Fuchs’ lab at Rockefeller University.  He is a member of the North American Hair Research Society and the Society of Investigative Dermatology.

Richard Chaffoo, MD, FACS, FICS

Dr. Chaffoo is a triple board certified plastic surgeon and hair restoration specialist based in La Jolla, CA. Dr. Chaffoo and his wife, Susan Stuart, M.D., F.A.A.D., who is a board certified dermatologist, co-direct La Jolla Hair MD. La Jolla Hair MD is the only hair restoration practice in Southern California under the direction of both a board certified dermatologist and plastic surgeon and one of only a handful of such practices nationwide. Dr. Chaffoo is board certified by the American Board of Plastic Surgery, the American Board of Otolaryngology-Head & Neck Surgery, and the American Board of Facial Plastic & Reconstructive Surgery. He is the past President of the San Diego Plastic Surgery Society and former Chief of Plastic Surgery, Scripps Memorial Hospital, Encinitas, Ca. Dr. Chaffoo completed 9 years of postgraduate training in surgery at such prestigious universities as Stanford University School of Medicine, UCSD School of Medicine, and Oregon Health & Sciences University. He is a member of the American Society of Plastic Surgeons and the American Society for Aesthetic Plastic Surgery. He has lectured both nationally and internationally at numerous plastic surgery society meetings and holds a clinical faculty appointment at UCSD Department of Surgery. Dr. Chaffoo is the author of numerous articles on plastic surgery which have been published in peer reviewed scientific journals.


Dr. McAndrews is a board-certified dermatologist specializing in the medical and surgical treatments for hair loss. He is certified by the American Board of Dermatology and the American Board of Hair Restoration Surgery. He has been performing FUT and FUE hair transplants and teaching the residents of USC/Los Angeles County Medical Center and has been a Guest Lecturer at numerous teaching programs across the United States and Internationally for more than 20 years. Dr. McAndrews runs his own medical practice in Pasadena, CA and is a Clinical Professor in the Department of Dermatology at the USC School of Medicine. He is on the Board of Governors and on the Executive Committee of the International Society for Hair Restoration Surgery, past President of the American Board of Hair Restoration Surgery, and has won numerous awards for his teaching of dermatology and hair restoration techniques. He has authored several textbooks on hair transplantation and rejuvenation. Dr McAndrews is also an Expert Medical Reviewer for the California Medical Board. He earned his MD at USC Medical School and performed his residency at the USC/Los Angeles County Medical Center.

Key Partners & Collaborators

Aleksander Ovsianikov, PhD

Prof. Aleks Ovsianikov is the head of research group “3D Printing and BioFabrication” at TU Wien (Vienna, Austria) and a globally recognized expert in laser-based nano- and micro-fabrication and tissue engineering technologies.  He is supporting Stemson’s work in optimizing the formation of the hair follicle using Stemson’s iPSC-derived cells.

David H Sachs, MD

David H Sachs, MD is a globally recognized leader in transplant immunology.  Through his work at Columbia University Medical Center and Massachusetts General Hospital, Dr. Sachs has pioneered the development of unique animal models to test transplantation tolerance of allografts and xenografts.  His pioneering research over 45 years has yielded many discoveries and helped illuminate the role of the human immune system in transplantation acceptance.  He has published over 700 articles in scientific journals and is a member of the Editorial Board of several journals in his field, including Xenotransplantation and Transplantation.  Dr. Sachs is supporting Stemson Therapeutics efforts with in-vivo animal testing for autologous and allogeneic solutions.

Sanford Burnham Prebys Medical Discovery Institute is the birthplace of Stemson Therapeutics and continues to be a key technology and development partner. Stemson is co-located on the Sanford Burnham Prebys campus where it can gain access to the Institute’s world-class scientific capabilities, knowledge base, and research facilities.

UpNano is a leader in the commercialization of high-resolution 3D printing systems using two-photon polymerization for industrial applications. Together with Prof. Aleks Ovsianikov, they are helping Stemson design and optimize a method for forming hair follicles using Stemson's iPSC-derived cells.

Allergan is a key partner providing funding, support and resources to advance Stemson’s product development