Clinical Sciences


Clinical Sciences by CenExel offers a unique opportunity for collaboration with pharmaceutical sponsors, CROs, and vendors, to support study development and conduct within the Sponsor’s clinical development program across the development lifecycle. These activities include Clinical Sciences support from pre-IND, Phase I, and translational medicine studies through to Phase III pivotal studies, peri-approval, and Phase IV studies. Clinical Sciences can provide scientific consulting for clinical development planning, study design, recruitment solutions, dose selection criteria to support more confident go/no-go decisions through the application of fit-for-purpose biomarkers, measures, and endpoints.


Clinical Sciences Leadership

Debra Hoffmeyer

Larry Ereshefsky, PharmD, BCPP

Chief Scientific Officer, Early Phase

Dr. Ereshefsky is an internationally recognized key opinion leader in clinical translational central nervous system research with a proven track record in designing and performing first-in-human, proof-of-concept, and a broad range of Phase I clinical pharmacology studies. With over 30 years’ experience leading early phase research sites, he is utilized as a global resource within CenExel, providing support to ensure consistency and quality across sites. Dr. Ereshefsky is actively involved in strategic planning for compound development. He helps design translational research programs and define the critical path towards regulatory approval. He has extensive experience working with regulatory agencies and developing strategic plans to address compound differentiation and reimbursement challenges.

Dr. Ereshefsky has contributed significantly to many drug approvals, including by providing drug development planning, PK evaluation, and methodological innovation. He has introduced strategies to de-risk early phase drug development through the application of neurocircuitry/biomarker-based (RDoC) strategies, e.g., continuous CSF sampling, QEEG, ERPs, PSG, fMRI, PET, and cognitive and behavioral paradigms.

Dr. Ereshefsky is a retired Regents Professor of Pharmacy, Psychiatry, and Pharmacology from The University of Texas at Austin and University of Texas Health Science Center at San Antonio. Subsequently, he was EVP and CSO for California Clinical Trials from 2003 to 2008 when it was acquired by Parexel International where his role was VP, Principal Pharmacologist, and Therapeutic Area Leader for CNS Early Phase until his departure in 2016. Dr. Ereshefsky has published almost 150 peer-reviewed scholarly articles and abstracts. He received his Pharm.D. from the University of Southern California. His post Post-Graduate Residency in Psychiatric Pharmacy/Psychopharmacology was completed at Los Angeles County+USC Medical Center (LAC+USC).

Dr. Robert Litman

Robert E. Litman, MD

Chief Scientific Officer, Psychiatry

Dr. Litman is the Medical Director and Principal Investigator for all clinical trials at CenExel CBH. He developed his interest in the treatment of schizophrenia at Massachusetts General Hospital, where he completed his residency in psychiatry. Shortly thereafter, he joined the Experimental Therapeutics Branch, National Institute of Mental Health, NIH, as a Senior Staff Fellow. He remained at NIH until 1995, where he continued to pursue his interest in schizophrenia, including investigating the effects of atypical neuroleptics biological and genetic markers in schizophrenia, as well as the development of better combination therapies for schizophrenia using the alpha-2 antagonist idazoxan. After leaving the NIH, he formed his own clinical trials research organization, first in conjunction with area hospitals, and then as a free-standing inpatient and outpatient clinical research organization now known as CBH Health. Since then, he has conducted over 300 Phase I-IV clinical trials and has participated in many of the important advances in pharmacotherapy of schizophrenia and other brain disorders.

Dr. Litman has an extensive background in psychopharmacology, the evaluation and treatment of schizophrenia, bipolar, major depression, anxiety, and Alzheimer disease. He serves as a consultant in psychopharmacology to many area hospitals and group practices, has over 30 academic publications, and frequently speaks about new advances in the field of psychopharmacology, and on the current issues regarding drug development for psychiatric illness. He is currently an Associate Professor of Psychiatry at Georgetown University Medical School (where he teaches and trains Psychiatry residents) and a Fellow and Diplomate of the American Board of Psychiatry and Neurology and Diplomate, Added Qualifications in Geriatric Psychiatry.

Dr. Robert Litman

Brandy Isaacks

Vice President, Project Management & Scientific Affairs

Brandy has a lengthy and admirable career history of more than 20 years in clinical research project management and operations. Most recently, she was serving as the lead for all Psychiatry in the Neuroscience Division at Syneos Health. Her background also highlights working with small to mid-size pharma and biotech clients, providing strategic guidance for clinical development planning, holistic team management, and ongoing client and program support. Brandy’s training and career began with conducting structured clinical interviews, clinical ratings, and electrophysiological (ERP) assessments at clinical research sites. Her work developing and sustaining client relationships has led her project teams to positive completion of numerous Phase I – IV clinical trials, resulting in approved products for psychiatry and neurology indications.

By focusing on early engagement, clinical team support, data quality, and project delivery, Brandy has found success in her CRO and client collaborations. She was recognized by the Healthcare Businesswomen’s Association (HBA) as a Luminary for being a role model for women in the healthcare industry and for mentoring and building industry leaders.

Internal Scientific Experts

Todd Bertoch, MD

Todd Bertoch, MD

Chief Medical Officer, CenExel JBR

Dr. Todd Bertoch, M.D. is a diplomate of the American Board of Anesthesiology. He graduated Summa Cum Laude with a Bachelor of Science Degree in Biochemistry from California State University at Fullerton and received a Doctor of Medicine degree from the Uniformed Services University of the Health Sciences in Bethesda, Maryland. After an internship in Internal Medicine, he completed his Anesthesiology residency at Wilford Hall Medical Center in San Antonio, Texas, where he was Chief Resident and received the Arthur B. Tarrow Outstanding Resident Award. He is a member of the esteemed Alpha Omega Alpha Honor Medical Society.

Dr. Bertoch served as an anesthesiologist in the United States Air Force until 2006 where he gained extensive experience in both trauma care and pain management. He is a recipient of the Air Force Achievement Medal, the Air Force Commendation Medal, and the Meritorious Service Medal.

After completing his military service, Dr. Bertoch served for 11 years as the managing partner of Prescott Anesthesia in Prescott, Arizona where his practice included a focus on cardiovascular surgery, chronic pain management and addiction medicine. Since joining JBR Clinical research in 2017, he has served as Principal Investigator for over 100 clinical trials, defended development programs for sponsors before the FDA, been invited to present study results on behalf of clients at professional meetings, designed and authored numerous clinical trial protocols, and has helped author several industry-related articles and white papers.

Rajeev Kumar, MD

Chief Medical Officer, CenExel RMCR

Dr. Kumar is one of the world’s foremost experts on movement disorders, with unparalleled experience and expertise treating and researching Parkinson’s disease, Huntington’s disease, Dystonia, and many other debilitating movement disorders. Trained at the renowned Mayo Clinic, Dr. Kumar has over two decades of experience working in the fields of Neurology and Movement Disorders, and as Medical Director of Rocky Mountain Movement Disorders Center and director of the Huntington’s Disease Center of Excellence both here and at the former Colorado Neurological Institute, he has solidified his status as one of the most trusted and respected professionals in the field.

Dr. Kumar has been dedicated to the care of patients with movement disorders in Colorado since 1998. He has been designated a Dystonia Doctor of Excellence by the Dystonia Medical Research Foundation. Dr. Kumar and his team serve individuals with movement disorders from early adulthood through advanced age. Our center is dedicated to helping patients with serious neurologic conditions achieve their life goals.

Robert A. Riesenberg, MD

Medical Director, CenExel ACMR

Dr. Riesenberg is the founder and principal investigator for CenExel ACMR. A research psychiatrist with four decades of experience, Dr. Riesenberg’s primary focus is on CNS, PK, healthy normal, and child/adolescent disorders. Dr. Riesenberg has been the principal investigator in over 600 studies.

Dr. Riesenberg earned a bachelor’s degree in both Zoology and Psychology from Memphis State University in 1972. In 1975, he earned his MD from the University of Tennessee. He is licensed to practice in Georgia.

Sanjiv K. Sharma, MD, CPI

Chief Medical Officer, CenExel AMRI

Dr. Sharma has been involved in memory research since 2009. In 2013, he started AMRI as the principal investigator. Since then he has worked on over 35 memory related protocols. Dr. Sharma has his board certification in internal medicine as well as geriatric medicine. He is passionate about caring for patients and families who are worried about memory loss.

Dr. Sharma graduated from Mahatma Gandhi Medical Memorial College in Jamshedpur, India and completed his residency in internal medicine at Jersey Shore University Medical Center. In 2000, Dr. Sharma opened his private practice, Geriatric Medical Center, in Toms River, New Jersey.

Scientific Advisory Board

Todd Bertoch, MD

Mark S Cohen, PhD


Dr. Cohen is the Technical Director of the Staglin Center for Cognitive Neuroscience at the UCLA School of Medicine. He is also the Director of the UCLA/Semel Neuroimaging Training Program, and he holds appointments in the UCLA Departments of Psychiatry & Biobehavioral Sciences, Neurology, Radiology, Biomedical Physics, Psychology, and Bioengineering. His research has been centered on the development of technological solutions to address difficult questions in neuroscience, particularly in Cognitive Neuroscience, and how the brain creates the mind. An early pioneer of functional brain imaging using magnetic resonance imaging, he has made meaningful contributions to many areas of neuroscience research including functional imaging, both imaging and EEG technology, cognitive science, and methods of analysis. Dr. Cohen worked in the private sector from 1985 to 1990 developing applications and technology of magnetic resonance imaging, before accepting a faculty appointment at Harvard, where he directed the high-speed MR imaging laboratory. He arrived at UCLA in 1993.

Dr. Cohen has published more than 200 peer-reviewed articles and papers, and holds patents in imaging and electrophysiology. He serves as a consultant and advisor to technology vendors in the neuroimaging space. He received his undergraduate training in both engineering at MIT and biology at Stanford. His Ph.D. is from the Rockefeller University.

Judith Jaeger, PhD

Principal Scientist, CognitionMetrics

President and Principal Scientist at CognitionMetrics LLC; Professor, Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, and Honorary Professor, Institute of Brain, Behaviour & Mental Health, University of Manchester.

20+ years experience as a clinican, teacher and academic researcher in psychiatry focused on cognitive dysfunction and its impact on disability. Internationally recognized clinical neuropsychologist and pharmaceutical executive. Previously Vice President for Clinical Trials at Cogstate, Inc, and Director Clinical Development at AstraZeneca Pharmaceuticals, Inc. Clinical and pharmaceutical development expert on cognitive, psychiatric and neurological disorders. Sought after key opinion leader and scientific consultant to most (14 of top 25) major pharma companies and several CRO’s and biotechs working in neuroscience. Over 65 peer-reviewed journal articles, one edited book, seven book chapters and one published neuropsychological test; 200+ published abstracts, conference presentations and invited lectures.

Bruce H Morimoto, PhD

Drug Development Consultant

Dr. Morimoto is a drug development consultant currently helping several biotech companies move their programs through clinical development and drug registration. He is also VP of Drug Development for Cerecin, a biopharmaceutical company focused on brain therapeutics. He has nearly 25 years of experience leading project teams in the development of innovative medicines, having previously held leadership roles at Alkahest, Celerion, Allon Therapeutics, MDS Pharma Services, and NeuroMed Technologies. Dr. Morimoto uses his extensive knowledge of translational medicine, CNS indications, and early-stage clinical research to provide guidance in the design and execution of nonclinical, clinical, and regulatory strategies. He also serves as a scientific advisor to the Michael J. Fox Foundation, chairing one of their scientific review panels.

Dr. Morimoto has published dozens of peer-reviewed papers on topics such as Alzheimer’s and other neurodegenerative diseases. He started his career on the faculty in the Chemistry Department at Purdue University where his independent research focused on neuronal signal transduction. He earned his doctorate in biochemistry from UCLA and completed a postdoctoral fellowship in molecular and cell biology at UC Berkeley.

Reid Robison, MD

Chief Medical Officer, Novamind

Dr. Robison is the Chief Medical Officer of Novamind, a mental health company enabling safe access to psychedelic medicine through a network of clinics, retreats, and clinical research sites. He is a founding board member at Psychedelic Institute, a non-profit dedicated to compassionate access to psychedelic therapies. He is the Medical Director at Center for Change, one of the top eating disorder treatment centers worldwide. He serves as Coordinating Investigator of the Multidisciplinary Association for Psychedelic Studies (MAPS) MDMA-assisted psychotherapy study of eating disorders, supervising the training and clinical research of all the MDMA therapy sites. He is also an adjunct professor at both the University of Utah and BYU.

After residency and fellowship training, Dr. Robison joined the tenure-track faculty at the University of Utah where he conducted trials of neuropsychiatric medicines and co-directed a genetics lab. After leaving full-time academia, he founded a Phase I-IV CNS clinical trials site and served as its PI for five years until he sold the company. Dr. Robison has extensive experience with ketamine in both research and clinic settings; he conducted his first research study with ketamine in 2011. A board-certified psychiatrist, he completed undergraduate studies in neuroscience at BYU then went to the University of Utah where he earned both his medical and MBA degrees.

Dr. Maguire

Harry Tracy, PhD

Founder and President, NI Research

Dr. Tracy is the founder and President of NI Research (NIR), the leading publisher of independent research on the neurotherapeutics industry. NIR’s bimonthly publication, NeuroPerspective, has provided comprehensive and frank overviews of the neurotherapeutics sector since 1995. It is utilized by pharmaceutical companies and venture capital professionals around the world. NIR also publishes NeuroLicensing, the annual evaluation of the ever-changing licensing environment for CNS companies and their programs. NIR provides consulting services to pharmaceutical companies of all sizes and to venture capital/private equity groups assessing CNS investment opportunities.

Dr. Tracy’s background includes 25 years of experience as a clinician and consultant in a variety of psychiatric and neurological settings. He received his Ph.D. from the University of Miami, and completed his clinical training at Massachusetts General Hospital/Harvard Medical School. He has been a Research Associate in the Department of Neurology at UC Davis.

Mark Varney, PhD

Chief Scientific Officer, PsychoGenics

Dr. Varney is the Chief Scientific Officer of PsychoGenics, a preclinical CRO with expertise in CNS and orphan disorders. He leads the company’s drug discovery and development efforts. He has more than 30 years of experience in drug discovery, clinical development, and executive leadership positions in the biotech and pharmaceutical industry. Dr. Varney co-founded Neurolixis, a company focused on the discovery and development of novel drugs for the treatment of CNS diseases, and served as CEO for eight years. Before founding Neurolixis, he was CEO for Cortex Pharmaceuticals (now RespireRx Pharmaceuticals). Earlier on, he held senior level R&D positions with Sepracor (now Sunovion), Bionomics, and Merck.

Dr. Varney’s career has focused on drug discovery and clinical programs for treating schizophrenia, depression, cognitive disorders, anxiety, pain, epilepsy and insomnia. He has been successful in developing drug candidates in several of these disease areas and has published over 75 peer-reviewed scientific papers and filed numerous patent applications relating to new chemical entities and methods of use. He received his Ph.D. and post-doctoral training in Pharmacology from Oxford University, UK.

Contact us if you’re interested in learning more about our Clinical Sciences services.