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Susan M. O'Brien, MD

Susan M. O'Brien, MD


Hematology-Oncology, Internal Medicine

Clinical Interests

chronic lymphocytic leukemia, chronic myeloid leukemia

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  • American Board of Internal Medicine, Internal Medicine
  • American Board of Internal Medicine, Medical Oncology
  • English
Medical School
University of Medicine and Dentistry of New JerseyMD Degree
University of Medicine & Dentistry of New JerseyInternal Medicine
The University of Texas MD Anderson Cancer CenterHematology/Oncology
Professional Positions
  • Professor — Division of Hematology/Oncology, Department of Medicine
  • Past Chair — National Comprehensive Cancer Network guidelines panel for chronic myeloid leukemia
Awards and Recognition
  • 2020 Giant of Cancer Care® — Leukemia
  • Best Doctors in America® — Medical Oncology and Hematology, 2015, 2016
More Information

Dr. Susan M. O'Brien is a UCI Health hematology oncologist who specializes in hematology and medical oncology.

Her clinical expertise is in the diagnosis and treatment of acute and chronic lymphocytic leukemia and she is actively involved in clinical trials.

O’Brien earned her medical degree at the University of Medicine and Dentistry of New Jersey in Newark, N.J., where she also completed her residency in internal medicine, followed by a fellowship in Hematology/Oncology at University of Texas MD Anderson Cancer Center in Houston, Tex.

An internationally recognized leader in the research of treatments for both chronic and acute leukemias, she has developed several important therapies now regarded as the standard of care for chronic lymphocytic leukemia (CLL). She has served as the principal investigator for more than 40 funded clinical protocols and led the initial clinical research into ibrutinib (Imbruvica) for patients with chronic lymphocytic leukemia. She continues to research Bruton tyrosine kinase inhibitor in patients with CLL and small lymphocytic lymphoma.

O'Brien is the author of more than 900 articles in peer-reviewed journals, numerous book chapters and abstracts, she is also a past chair of the National Comprehensive Cancer Network guidelines panel on chronic myeloid leukemia. She was recently inducted into the 2020 Giants of Cancer Care® program by a panel of her peers in cancer research and clinical care.

She sees patients at the cancer center in Orange.

UCI Health Chao Family Comprehensive Cancer Center
101 The City Drive South, Building 23
Orange, CA 92868
Fax: 855-211-3729