Los Angeles (Westlake), California

Principal Investigator
Mark Leibowitz, MD is an experienced and skilled Investigator with approximately 25 years of research experience. Dr. Leibowitz has participated in an estimated 500 studies from Phase I-IV across a variety of different indications. As part of his research portfolio, Dr. Leibowitz has conducted highly complex studies in healthy subjects and diverse patient populations including continuous cerebrospinal fluid studies, First in Human, Single and Multiple Ascending Dose studies, Ethnic bridging programs, QTc studies, as well as, serving as Principal Investigator for many adaptive trial designs. His experience includes leadership roles such as Medical Director for research sites located in California and Texas. In addition, he is currently a contributing member for a Data Safety Monitoring Board.

Principal Investigator
Juan Pablo Frías, MD, a native of Chile, completed his undergraduate studies at the University of Florida and received his medical degree from Vanderbilt University School of Medicine. After serving 5 years as a General Medical Officer in the US Navy, he completed his training in Internal Medicine at Vanderbilt University and the University of Tennessee, and his Fellowship in Endocrinology, Diabetes and Metabolism at the University of California, San Diego. Dr. Frías has held leadership positions in Clinical and Medical Affairs at Eli Lilly, Amylin Pharmaceuticals, Pfizer, and Johnson & Johnson, where he served as Chief Medical Officer and Global Vice President of Clinical and Medical Affairs, Diabetes Care. Dr. Frías has held academic positions at the University of Colorado Health Sciences Center, Barbara Davis Center for Diabetes, and the University of California San Diego School of Medicine, where he is currently on the clinical faculty. He is also active in the non-profit organization Taking Control of Your Diabetes (TCOYD), where he lectures at the organization’s Latino Initiative patient conferences and provides continuing medical education for healthcare providers. Dr. Frías has been involved in diabetes and metabolism-related research for over 15 years and has authored numerous publications in this field.

Principal Investigator
Maricor Grio, MD is a clinical research physician with over 15 years of experience. She is a board certified Pediatric Nephrologist and General Pediatrician and graduated from the University of Miami School of Medicine with her medical degree. She is also a NIH Scholar with a Master’s in clinical research design and statistical analysis. Besides Principal Investigator, some of her previous titles include Clinical Assistant Professor of Pediatrics, Pediatric Nephrologist, Medical Director, and Urgent Care Physician. Dr. Grio is passionate about leadership and investigator roles in clinical trials, especially in nephrology, inflammation, pediatrics and medical devices. Her therapeutic experience also includes Endocrinology, Ophthalmology, and Dermatology in adult patients.

Principal Investigator
David Guzman, MD is an experienced board-certified Internist who joined Velocity Clinical Research in 2022. He completed his undergraduate studies at Massachusetts Institute of Technology (MIT) and received his medical degree from the University of Chicago, Pritzker School of Medicine. He completed his postgraduate training in Internal Medicine at Northwestern University McGaw Medical Center and remained there as an Instructor in Clinical Medicine. Dr. Guzman participated in Community Based Clinical Trials at a federally-qualified health center in Chicago from 1990 to 1993. He is a native Spanish speaker and has served various Latino communities in Chicago, south Florida, and now southern California with a focus on providing both primary care and urgent care.

Principal Investigator
John Nelson, PA-C is a skilled Physician Assistant with over 20 years of medical and clinical research experience in a variety of indications such as Pulmonary Medicine and Critical Care, Internal Medicine, Gastroenterology, Infectious Disease, Emergency Medicine, and Geriatrics. He obtained his Physician Assistant certification from the USC School of Medicine. John currently serves as a Sub-Investigator for multiple Velocity sites in the LA area and is a member of the California Academy of Physician Assistants.