Dr. Ivan I. Kirov, Pediatric Oncology

Dr. Ivan I. Kirov, Pediatric Oncology

  • Ivan I Kirov MD
  • Appointments:
  • Office: 714-509-4348
  • Specialty: Oncology
  • Board Certified: Pediatric Hematology/Oncology, Hematology,

A leading expert in pediatric oncology/hematology, Dr. Kirov serves as CHOC Specialists director of oncology, as well as the director of the lymphoma program and recurrent/refractory cancer program.

On the forefront of innovative research, Dr. Kirov’s clinical research interests include Hodgkin’s and Non-Hodgkin’s lymphomas, leukemia, stem cell transplantation and innovative therapies for patients with recurrent cancer. He is a principal investigator for CHOC Oncology Group (COG) Phase I studies at CHOC Hospital, and co-investigator in all ongoing COG studies. Dr. Kirov is a principal investigator in several pharmaceutical industry sponsored clinical studies in the areas of chronic myeloid leukemia and stem cell transplantation. 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.

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 in pediatric and adult hematology in Bulgaria where he went on to become a leading 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.

Research Focus


Ivan I Kirov MD is on staff at CHOC Hospital in Orange and CHOC Mission Hospital.


Outpatient Clinic, Hyundai Cancer Institute at CHOC
1201 W. La Veta Avenue
Orange, CA 92868
phone: 714-509-8636
fax: 714-509-4748


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

Academic Appointments

  • Assistant Clinical Professor
    UC Irvine
  • Assistant Professor of Pediatrics
    University of California, Irvine

Administrative Appointments

  • Medical Director, Oncology
    CHOC Specialists

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

Honors and Awards

  • Physicians of Excellence 2009 – 2015
    Orange County Medical Association

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.

Professional Organizations

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


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.

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.

Clinical Trials

TINI, Total Therapy For Infants with Acute Lymphoblastic Leukemia (ALL) I

Clinical Trial Protocol # TINI | Leukemia | Contact (714) 509-8646

ADVL1513, A Phase 1 Study of Entinostat, an Oral Histone Deacetylase Inhibitor, in Pediatric Patients with Recurrent or Refractory Solid Tumors, including CNS Tumors and Lymphoma

Clinical Trial Protocol # ADVL1513 | Adolescents and Young Adults, Brain Tumor/Central Nervous System/Neuro-Oncology, Recurrent/Refractory Cancer, Solid Tumors | Contact (714) 509-8646


Dr. Ivan Kirov - leukemia
Understanding Leukemia in Children and Teens

Pediatric oncologist Dr. Ivan Kirov discusses leukemia in children and teens, symptoms to look for, how it is treated.