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Medical Staff

Medical StaffThe experienced and highly trained clinical staff at Medvin Clinical Research works towards the specific needs of our patients and bring their expertise into application through exceptional care. Our team of licensed physicians has been practicing in their field for several years and is recipients of several awards and honors. To better accommodate the needs of our patients, Medvin staff comprises of many individuals who are bilingual in English and other languages such as Spanish, Arabic and Hindi.

The Medvin team excels in providing the most compassionate care to our patients and guide you through your entire recovery process.


Our staff


Vipul Vineet, MBA

Vipul Vineet, MBA

Research Director

Vipul Vineet graduated from UCLA with a degree in Psycho-biology. He furthered his education by obtaining an MBA degree from University of Redlands. Vipul has been actively involved in research since 2004 and has worked in several specialty areas at renowned research institutions such as UCLA and VA. Vipul has been with Medvin Clinical Research since its inception and has played a vital role in its expansion and diversification across the Los Angeles area. Through his extensive knowledge and experience, Vipul contributes to the success of the organization by managing critical day-to-day operations, bringing in new business opportunities and striving for a healthier tomorrow through Medvin’s endeavors.


Samy Kamal Metyas, MD, MSc, FACP, FAC

Samy Kamal Metyas, MD, MSc, FACP, FAC

Principal Investigator – Covina Office

Trained in internal medicine, orthopedic surgery, and rheumatology, Dr.Metyas is board certified and has medical staff privileges at Citrus Valley Medical Center’s Queen of the Valley campus in Covina and Inter-Community campus in Wes Covina. He continues to teach at LAC/USC Medical School and is an experienced researcher in the fields of rheumatology and connective tissue disease. Dr. Metyas is the recipient of multiple awards and has been featured on CNN.


Charles Weidmann, M.D.

Principal Investigator – Van Nuys Office

Dr. Weidmann earned his medical degree from Georgetown University School of Medicine in Washington, D.C. He continued his Internal Medicine Residency followed by Fellowship training in Rheumatology at Olive View Medical Center. His research interests include: breakthrough treatments for Rheumatoid Arthritis, Osteoarthrits and Systemic Lupus Erythematosus. He has been in private practice in the San Fernando Valley for over 25 years and has been actively involved in clinical trials since 2000. Dr. Weidmann is fluent in English and Spanish.


Darice Yang, M.D.

Principal Investigator – Whittier Office

Dr. Darice Yang graduated from Temple University School of Medicine in Philadelphia, PA. She moved on to LAC-USC Medical Center to complete her Internal Medicine residency. She became an Assistant Professor in Clinical Medicine at the USC Keck School of Medicine, followed by her Fellowship in Rheumatology at LAC-USC. She is board-certified in both Internal Medicine and Rheumatology. The experience she gained as a Sub-Investigator at LAC-USC helped her assume the role of a Principal Investigator at Medvin Clinical Research. Dr. Yang has been an integral part of the team since taking over as PI in 2010 and has thus far led 14 trials to their desired goals. She is part of a group practice in Whittier specializing in Rheumatology. Her interests include providing cutting-edge treatment for diseases such as Rheumatoid Arthritis, Systemic Lupus Erythematosus, Osteoporosis, Osteoarthritis, and systemic vasculitides, to name a few.


Karleen Su, M.D.

Tien-I Karleen Su, M.D.

Principal Investigator – Whittier Office

Dr. Su earned her medical degree from UCLA and completed her Fellowship training in Rheumatology at USC Keck School of Medicine. She has extensive knowledge of research trials and has several publications and studies under her name. Dr. Su is currently involved in a group practice in Whittier and Downey. Besides medicine, Dr. Su is an ardent photography enthusiast and features her work on her own website and blog.



Richard McGuire, M.D.

Richard McGuire, M.D.

Principal Investigator – La Mirada Office

Dr. McGuire graduated from Yale University with a degree in Biology. He received his MD degree from New York University and completed his residency in Internal Medicine at Yale University. He completed a fellowship in Gastroenterology at University of California, San Francisco, including two years of research. Dr. McGuire has been practicing in Southern California for over twenty years. He is married with two daughters.


Gilbert Gelfand, M.D.

Sub-Investigator – Whittier/ La Mirada Office

Dr. Gelfand graduated with a medical degree from Autonomus University in Barcelona, Spain and completed his Residency and Fellowship in Rheumatology at Coney Island Hospital in New York. Dr. Gelfand, over the years, has been widely published and has held multiple positions at several academic institutions such as USC. He is a widely known and respected physician practicing in the Los Angeles area for the past 30 years. Dr. Gelfand’s research efforts have been primarily focused on improving the lives of people with autoimmune disorders.


Raz Khavari, M.D.

Sub-Investigator – Van Nuys Office

Dr. Khavari earned her medical degree from the Medical College of Wisconsin in Milwaukee, WI. She continued her Internal Medicine residency at Olive View Medical Center through UCLA and went on to complete the Fellowship training in Rheumatology. Her research interests include emerging treatments for RA and Systemic Lupus Erythematosus. She’s been in private practice in Van Nuys for the past 3 ½ years.


Anne Violet Quismorio, M.D.

Anne Violet Quismorio, M.D.

Sub-Investigator – Covina Office

Dr. Quismorio earned her medical degree from the Keck School of Medicine at the University of Southern California. She then continued at USC to complete a residency in Internal Medicine, as well as a fellowship in Rheumatology. Her research interests include issues related to the transition of care from pediatric to adult providers for patients with juvenile rheumatologic disorders, as well as effective strategies for the prevention of osteoporosis. She enjoys world travel and the fine arts, and is fluent in Spanish.