CHOC Docs :: Provider Profile

Ivan I Kirov, MD

Dr. Kirov is on staff at CHOC Orange & CHOC Mission

Oncology, CHOC Children's Specialists


Board Certified:
Pediatric Hematology/Oncology

Research Focus:
Hodgkin’s and non-Hodgkin’s lymphomas, recurrent cancers, and bone marrow transplants

CHOC Children's Specialists
1201 W La Veta Avenue
Orange, CA 92868
phone: (714) 509-8636
fax: (714) 509-4748
map & directions

Web Site:

Physician / Researcher Bio

A leading expert in pediatric oncology/hematology, Dr. Kirov serves as CHOC Children’s Specialists director of the lymphoma program and recurrent/refractory cancer program. A prolific and respected author, Dr. Kirov has written many publications and has been published in a number of journals including Bone Marrow Transplant and the Journal of Pediatric Hematology/Oncology.

On the forefront of innovative research, Dr. Kirov's clinical research interests include hodgkin's and non-hodgkinls lymphomas, chronic myelogenous leukemia, targeted therapy, recurrent cancers, and stem cell transplant. He is a principal investigator for Children's Oncology Group (COG) Phase I studies at CHOC Children's Hospital and co-investigator in all ongoing COG studies at CHOC. Dr. Kirov is a principal investigator in several pharmaceutical industry sponsored clinical studies in the areas of chronic myeloid leukemia and stem cell transplantation.

Dedicated to clinical excellence, Dr. Kirov is board certified in pediatric hematology/oncology. He earned his medical degree from the Medical Academy in Sofia, Bulgaria. He completed his residency training and fellowship programs in Bulgaria where he went on to become a highly regarded pediatric hematologist/oncologist for more than 12 years. When Dr. Kirov relocated to the United States, he became a visiting fellow in the bone marrow transplant program at the Johns Hopkins Hospital Oncology Center. He then went on to complete a residency in pediatrics at Westchester County Medical Center, New York and postdoctoral fellowship in pediatric hematology/oncology at CHOC Children’s.

Administrative Appointments

  • Oncology, CHOC Children's Specialists

Academic Appointments

  • Assistant Professor of Pediatrics
    University of California, Irvine


  • Postdoctoral Fellowship
    Pediatric Hematology/Oncology at Children's Hospital of Orange County, Orange, California
  • Residency
    Pediatrics Residency at Westchester County Medical Center, New York Medical College, Valhalla, New York
  • Visiting Fellowship
    Bone Marrow Transplant Program at Johns Hopkins Hospital Oncology Center, Baltimore, Maryland
  • Postdoctoral Fellowship
    Pediatric Hematology/Oncology at the National Institute of Hematology, Medical Academy, Sofia, Bulgaria
  • Medical School
    Medical Academy, Sofia, Bulgaria

Board Certifications

  • Pediatric Hematology/Oncology
    American Board of Pediatrics

Honors and Awards

  • Orange County Medical Association's Physicians of Excellence 2010 - 2013

Professional Organizations

  • American Society of Hematology
  • Bulgarian Medical Association - Foundation Member
  • Bulgarian Society against Leukemia and Tumors in Children - President & Founder

Completed Research Support

  • Pilot grant for Chao Family Comprehensive Cancer Center seed funding.
    Is loss of SXR expression or function associated with B-cell lymphomas in humans?
    Role: Co-Principal Investigator
  • Pilot grant for Chao Family Comprehensive Cancer Center seed funding.
    Pilot project to study FGFR3 expression and mutations in pediatric patients.
    Role: Co-Principal Investigator

Published Works

Abla O, Sandlund JT, Sung L, Brock P, Corbett R, Kirov I, Griffin TC, Blaser S, Weitzman S. A case series of pediatric primary central nervous system lymphoma: favorable outcome without cranial irradiation. Pediatric Blood Cancer. 2006 Dec;47(7):880-5.

Neudorf S, Nourani A, Kempert P, Shen V, Sender L, Kirov I. Chemotherapy and donor leukocyte infusion for relapsed juvenile myelomonocytic leukemia (JMML). Bone Marrow Transplant, 2004; 33: 1069

Lones MA., Kirov I., Said JM., Shinataku IP., Neudorf S. Post-transplant lympho-proliferative disorder after autologous stem cell transplantation in a pediatric patient. Bone Marrow Transplant 2000; Nov; 26 (9): 1021-1024.

Kirov I., and Neudorf S., Biology and clinical utility of hematopoietic stem cells. Pediatric Pathology and Molecular Medicine 2000; 19: 283-302.

Abu-Ghosh, Bracho F., Kirov I., and Cario MS., Hematopoietic Colony-Stimulating Factors In: Textbook of Critical Care, 4th Edition, Grenik, A (Ed), Philadelphia, Saunders, 2000; pp 542-561.

Konstantinov D., Bobev D., Michailov G.,    Kirov I. A seven years experience in treatment of childhood leukemia in Bulgaria. Pediatric Hematology Oncol 1998 Mar-April; 15(2): 157-164.

Presentations and Abstracts

  • Kirov I, Shen V, Sender L, Lones M. Pediatric Diffuse Large Cell Lymphomas in Primary Immunodeficiency have a Non-Germinal Center-B Phenotype.45th Congress of the International Society of Pediatric Oncology, September 2013, Hong Kong. Pediatr Blood Cancer, September 2013, 60, suppl 3:82

    Kirov I, Neudorf S, Sender L, Messina J, English M, Crook N. Da-EPOCH-R and EPOCH-R in Treatment of Adolescent Patients with DLBCL. Fourth International Symposium on Childhood, Adolescent and Young Adult Non-Hodgkin's Lymphoma, November 2012, New York, NY. British Journal of Hematology, 2012, 159, suppl 1:128

    Huynh V, Kirov I, Neudorf S, Zadeh T, Lones M.Post-Transplant Lymphoprolipherative Disorders in Pediatric Bone Marrow Transplanted Recipients Have Non-Germinal Center Phenotype and Unique Ctytogenetic Abnormalities. Fourth International Symposium on Childhood, Adolescent and Young Adult Non-Hodgkin's Lymphoma, November 2012, New York, NY. British Journal of Hematology, 2012, 159, suppl 1:107

    Fraser C, Brown P, Megason G,, Hyo Seop Ahn, Cho B, Kirov I, Frankel L, Aplenc R, Bensen-Kennedy D, Munteanu M, Weaver J, Harker-Murray P. Open-Label Bendamustine for Pediatric Patients with Relapsed or Refractory Acute Leukemia: Safety and Efficacy Outcomes. In: 53rd ASH Annual Meeting, December 2011, San Diego, California. Blood. 2011 Nov; 118(21): 3602.

    Richardson P, Smith A, Grupp S, Kernan N, Arai S, Haut P, Triplett B, Chan KW, Gillio A, Symons H, Adams R, Horn B, Lucas K, Martin PL, Mineishi S, Ball E, Boyer M, Fort J, Kirov I, Lehman L, Madigan C, Massaro J, D’Agostino R, Hannah AL, Tudone E, Hume R, Iacobelli M, Soiffer R, and the Defibrotide Study Group. Defibrotide (DF) in the Treatment of Hepatic Veno-Occlusive Disease (VOD) in Stem Cell Transplant (SCT) and Non- SCT Patients (Pts): Results of a Treatment IND Expanded Access Protocol. In: 53rd ASH Annual Meeting, December 2011, San Diego, California. Blood. 2011 Nov; 118(21): 487.

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UC Irvine

CHOC Children's is affiliated with the UC Irvine School of Medicine