Tosk’s leadership consists of pharmaceutical industry veterans, including the CEO, Brian Frenzel, who co-founded four successful medical startups after leading global planning activities at Syntex Corporation, then the largest West Coast pharmaceutical company.


Brian Frenzel, President, CEO, and Director
Mr. Frenzel is a highly experienced biomedical company executive, previously serving as CEO of Centaur Pharmaceuticals, CEO of Adeza Biomedical, CEO of Vesta Medical, and COO of Genelabs Technologies, all of which went public or were acquired by large pharmaceutical companies. Earlier in his career, Mr. Frenzel was director of corporate planning at Syntex Corporation, a principal at Booz, Allen & Hamilton, a consultant at the Boston Consulting Group, and a lieutenant in the United States Navy Nuclear Power Program. Mr. Frenzel holds a BS in physics and an MBA from Stanford University.

Om Srivastava, PhD, Senior Vice President Operations and Product Development
Dr. Srivastava has over 25 years of experience in pharmaceutical product development, formulation, process development, API and finished drug product manufacturing, and supply chain management for small molecules and biologics. Previously, Dr. Srivastava served as Vice President of Operations at Hexima Ltd., Director of CMC and Pharmaceutical Development at Mirati Therapeutics, and Program Director at the Alberta Research Council. Dr. Srivastava has been responsible for CMC for a number of INDs, clinical studies, and NDAs, including, Dificid ® , ZstatFlu ® , Mirataz ® , IV Zimeta ® , and Krazat ® . Dr. Srivastava received his PhD from Lucknow University, India in bioorganic and medicinal chemistry. He is the author or co-author of over 75 publications, issued patents, conference proceedings, and invited lectures.

Emile Youssef, MD, PhD, Chief Medical Officer
Physician-scientist with a well-rounded background, including, academic, pharmaceutical, biotech, and CRO experience. Dr. Youssef is Board Certified in oncology from Osaka City University Medical School. Before joining Tosk, he led early clinical development and proof of concept studies for Novartis, Eisai, Celgene, and Bayer. Dr. Youssef’s most recent positions were as Vice President of Oncology/Hematology Scientific Solutions at Worldwide Clinical Trials, a clinical study management company, and Vice President and Head of Oncology at Oryn Therapeutics. He is a thought leader in oncology development who has published more than 30 papers in clinical cancer journals while holding global hematology and oncology society memberships in the US, Europe, and Japan. Dr. Youssef completed his post-doctoral training at MD Anderson Cancer Center and holds a PhD in molecular oncology, as well as a Surgical Oncology Diploma from Osaka City University, and a Doctor of Medicine (MB, Bch) from Cairo University.

Stephen Yanofsky, PhD, Vice President Research
Dr. Yanofsky is an experienced cell biologist, pharmacologist, and project manager. He held positions of increasing responsibility with Affymax, Receptron, Multispan, and Amunix before coming to Tosk. His prior positions have involved scientific work in molecular biology, biochemistry, and pharmacology, including extensive work in cell culture and analytical assay development to support drug discovery efforts. Dr. Yanofsky holds a PhD in biochemistry from the University of California San Francisco.

Outside Board Members

Harold Crow, Chairman of the Board
Mr. Crow is a retired pharmaceutical and life science executive with experience in general management, product development, business development, sales, and marketing. Mr. Crow co-founded and served as President and CEO of Hystagel and Aquintel. Previously, Mr. Crow held the positions of director of international operations at Alza Corporation and area director for an eight-country Asian region and director of business and public sector development for Syntex Corporation. Mr. Crow received a BA from San Francisco State University and holds a certificate in finance and accounting from the Wharton School of Business.

Charles Garvin, Director
Mr. Garvin is the CEO of Riptide Bioscience. He has been Chairman, CEO, or controlling shareholder at a number of tech and biotech companies during his career. Mr. Garvin served as an officer and member of the Board of Directors at the Boston Consulting Group and was a founder of the Beta Group, a seed capital firm which has incubated a number or successful medical technology companies. Mr. Garvin holds a BA and a JD from Harvard University and studied at Oxford University as a Rhodes Scholar.


J. Lawrence Marsh, PhD, Scientific Advisor
Dr. Marsh is Professor of Developmental and Cell Biology and of Pathology and Director of the Developmental Biology Center at the University of California, Irvine. Dr. Marsh is an internationally recognized expert in using Drosophila to engineer models of human diseases to identify and validate therapeutic targets and drugs that slow the disease processes. He serves on the editorial board of BioEssays and is a fellow of the American Association for the Advancement of Science.

Giuseppe Pizzorno, PhD, DPharm, Scientific Advisor
Dr. Pizzorno is Professor, Associate Dean for Research, and Chief Research Officer at the University of Tennessee Health Science Center College of Medicine and Erlanger Health System. Previously, he was Vice President of Research Operations and Deputy Director of the Nevada Cancer Institute where he led translational cancer research activities.

David Shuman, DVM, Scientific Advisor
Dr. Shuman is a graduate of the School of Veterinary Medicine at the University of California Davis. He has extensive experience in small animal, large animal, and laboratory animal medicine, and has more than 20 years of experience working with USDA registered research facilities. He owns and operates the Westside Animal Hospital in Santa Cruz, California.

William Sullivan, PhD, Scientific Advisor
Dr. Sullivan is professor of Molecular, Cell, and Developmental Biology at the University of California Santa Cruz. Dr. Sullivan is a recognized expert in using Drosophila embryonic divisions for real-time profiling of anti-cancer drugs and the molecular and cellular mechanisms driving cytokinesis.

Jeffrey Thomas, PhD, Scientific Advisor
Dr. Thomas is an Assistant Professor of Cell Biology and Biochemistry at the Texas Tech University Health Sciences Center. Dr. Thomas is an expert in Drosophila genetics, particularly as they relate to development, reproduction, and disease. He holds appointments in both the School of Medicine and the Graduate School of Biomedical Sciences.

Steven Deitcher, MD, Medical Advisor
Dr. Deitcher is a physician-entrepreneur who has developed therapeutics, diagnostics, and drug-device combinations for hematology, oncology, infectious disease, and cardiovascular medicine. He holds BS and MD degrees from the Northwestern University Medical School. Dr. Deitcher is the author of over 225 peer-reviewed journal papers, abstracts, and book chapters.

Joel Epstein, DMD, Medical Advisor
Dr. Epstein is Professor and Director of Cancer Dentistry at the Samuel Oschin Comprehensive Cancer Institute in Los Angeles and Medical Director of Dental Oncology Services at the City of Hope Comprehensive Cancer Center in Duarte, CA. Dr. Epstein is a specialist in maxillofacial cancer and recently received the Distinguished Service Award of the International Society of Oral Oncology.

Robert Haddad, MD, Medical Advisor
Dr. Haddad, MD is a Professor of Medicine at Harvard Medical School. He is the McGraw Chair and Division Chief of the Head and Neck Oncology Program, and a member of the Department of Adult Oncology, at Dana-Farber Cancer Institute in Boston. Dr. Haddad’s research is focused on identifying new treatments in head and neck cancer involving the use of induction, concurrent chemotherapy, and radiation therapy for patients with locally advanced head and neck cancer, as well as the development of novel therapeutic agents for treating advanced disease.

Rajesh V. Lalla, DDS, PhD, Medical Advisor
Dr. Lalla is Professor and Associate Dean for Research at the University of Connecticut School of Dental Medicine. He has extensive experience conducting clinical research on mucositis and other side-effects of cancer therapy. Dr. Lalla has also led the development of international clinical practice guidelines for oral and gastrointestinal mucositis. He is a past President of the Multinational Association of Supportive Care in Cancer (MASCC) and a past Chair of its Mucositis Study Group.

Paul Page, MD, Medical Advisor
Dr. Page is a board-certified radiation oncologist with a special interest in overcoming treatment-limiting side effects. He has been a principal investigator for clinical trials investigating radioprotectants in head and neck and lung cancers. Prior to earning a master’s degree in biomedical engineering from UC Davis and his MD from UC San Francisco, he worked in Silicon Valley and served as a nuclear submarine officer in the US Navy.

Ravi Patel, MD, Medical Advisor
Dr. Patel is the founder and director of the Comprehensive Blood and Cancer Center in Bakersfield, CA and an Associate Clinical Professor at the University of California Los Angeles. Dr. Patel is American Board Certified in internal medicine with a subspecialty in medical oncology. In addition to directing a leading West Coast cancer center, Dr. Patel is a practicing oncologist and has been the principal investigator for over 50 human clinical studies of cancer therapeutics.

Nabil F. Saba, MD, FACP, Medical Advisor
Dr. Saba is Professor, Department of Hematology and Medical Oncology and holds a joint appointment as Professor in the Department of Otolaryngology at Emory University School of Medicine. Dr. Saba also serves as Director of the Head and Neck Cancer Medical Oncology Program at Winship Cancer Institute of Emory University. Dr. Saba is the Chair of the National Cancer Institute’s Task Force for Recurrent Metastatic Head and Neck Cancer, and chairs the Rare Tumors Task Force of the National Cancer Institute’s Head and Neck Cancer Steering