Physicians / Principal Investigators

Medical Director

Dr. Juan Velez, MD, an accomplished and beloved Obstetrics & Gynecology specialist, has been serving the Orange County, CA communities for more than three decades. He has a broader range of research interests in not only women's health but most therapeutic areas. His work conducting clinical research in women's health, urology, cancer detection, metabolic disorders, and Alzheimer's disease has contributed significantly to our understanding of these fields. 

A distinguished Developmental/Behavioral Pediatrician and Sleep Medicine specialist, Dr. Gary Feldman, MB ChB, serves as the Medical Director of the Stramski Children’s Developmental Center at Miller Children’s and Women's Hospital Long Beach, as well as a member of clinical faculty at the University of California, Irvine. With 20 years experience treating specialized behavioral and developmental needs, Dr. Feldman has become highly respected and sought-after for evaluating and treating children with Fragile X Syndrome, Autism Spectrum Disorders, learning disabilities, mood disorders, ADHD, and sleep disorders. Throughtout his career, he has continued to place a high value on research, maintaining regular involvement and partnership with studies working to promote medical advancements in the field. 

Medical Director

A seasoned investigator in the past 10 years, Dr. Siu has led over 120 studies, exploring areas from diabetes, back pain, migraine, hypertension, high cholesterol, asthma, COPD, IBS, and Alzheimer's studies. His interests span broadly from cardiovascular, pain management, rheumatology,  neurology,  gastroenterology, respiratory diseases,   vaccines, and psychiatry, reflecting his expertise in clinical trials and dedication to multi-faceted research improvement.

Dr. Geiger, a devoted hospitalist physician at Saddleback Memorial Medical Center and Mission Viejo Hospital, board-certified in both internal medicine, as well as palliative care medicine, boasts 15 years of clinical research experience. Since 2009, he's been at the forefront of diverse research projects spanning Alzheimer's, UTI, cardiovascular diseases, and chronic pain, demonstrating his broad expertise and commitment to medical advancement.

An expert in psychiatry and neurology, Dr. Hassamal has dedicated over 12 years to the medical field. His research encapsulates Alzheimer's, Parkinson's, addiction medicine, mental health and psychiatry, demonstrating a deep commitment to unfolding new knowledge in these areas. He is an assistant professor of medical education and psychiatry at the California University of Sciences and Medicine.

Site Director/Sub-Investigator

With a decade of nurse practitioner experience in women's healthcare, Maggie Wang transitioned into clinical research several years ago, finding a deep passion for it. She started as a Sub-Investigator, contributing to over a dozen trials ranging from birth control methods, Alzheimer's disease to early cancer detections. Quickly advancing, she became a site manager for three clinical research sites, overseeing all aspects of trial execution and regulatory compliance. With her rich clinical background and thorough understanding of research protocols, GCP and regulatory guidelines, and compassionate patient care, Maggie brings valuable insights to her role to deliver high-quality and impactful clinical research.

Clinical Research Coordinator

Clinial Research Coordinator

Clinical Research Coordinator