Assoc. Prof. Dr. Jeliazko Arabadjiev, MD, PhD, began his professional career as a medical doctor in Varna, where he graduated with honors from the Faculty of Medicine at the Medical University “Prof. Dr. Paraskev Stoyanov” in 1997. He has worked as both a physician and a clinical trials expert since then. Between 2009 and 2015, he specialized in medical oncology at the Specialized Hospital for Active Treatment in Oncology in Sofia. As a specialist, he worked at the Medical Oncology Clinic of City Clinic Oncology Center in Sofia (currently known as Asklepios University Hospital Mladost) and later at the Medical Oncology Clinic at Acibadem City Clinic Tokuda Hospital in Sofia. Since 2019, he has been the head of the clinic.

In 2020, Dr. Arabadjiev earned a Ph.D. in Oncology from the Medical University of Varna, successfully defending his dissertation on breast cancer treatment. In 2021, he was appointed to the academic position of Associate Professor in Oncology. He also holds a Master’s degree in Healthcare Management from the University of National and World Economy in Sofia. He is a part-time assistant at the Department of Internal Medicine at the Faculty of Medicine of Sofia University “St. Kliment Ohridski.”

Dr. Arabadjiev is the author of two monographs, “Immunotherapy and Breast Cancer Treatment” and “immune related toxicity from Immunotherapy in the Treatment of Oncological Diseases.” He has authored or co-authored more than 70 publications in national and international scientific journals and has contributed to guidelines, textbooks, and monographs in cancer treatment.

He serves on the editorial boards of several international and national peer-reviewed scientific journals. His clinical interests lie in breast cancer, prostate cancer, lung cancer, cancer immunology, immuno-oncology, targeted therapy, and personalized medicine. Dr. Arabadjiev is the principal investigator and sub-investigator in several international multicenter clinical trials.

He has completed oncology training in leading clinics in Israel, Belgium, Italy, and Germany and is a member of Bulgarian, European, and American oncology societies. He frequently gives lectures in Greece, Serbia, and Romania. 

Dr. Arabadjiev is the chairman of the Board of the Bulgarian Society of Immuno-Oncology and the Board of the Institute for Breast Cancer Research and Treatment. He initiated the “Scientorium Juvenorum” program—a school for young oncologists and immunologists.

He represented Bulgaria in the European Society for Medical Oncology (ESMO) until 2019 and in 2022 was elected to the Board of the EU Cancer Mission of the European Commission, representing the Mission in Bulgaria, Romania, and Lithuania. 

Since 2019, Dr. Arabadjiev has served on the Expert Council for Medical Oncology under the Minister of Health and has been an advisor on health matters to members of the 47th, 48th, and 49th National Assembly of Bulgaria. He is a member of the Bulgarian Medical Association and, in 2024, was elected to the Ethics Committee of the Sofia branch of the BMA.

He has been recognized and awarded multiple times by cancer patients and patient organizations, including in the “Doctors We Trust” ranking of the *24 Chasa* newspaper since 2019.

Dr. Arabadjiev is fluent in English, Russian, competent in Italian, French, and Greek.