Jeliazko Arabadjiev

Prof. Dr. Jeliazko Arabadjiev

orcid

Research Focus & Metrics

Academic Career Length

4Years (2023-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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Journal Article
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KTKalina Tumangelova-Yuzeir
Kalina Tumangelova-Yuzeir
KMKrasimir Minkin
Krasimir Minkin
IAIvan Angelov
Ivan Angelov
EIEkaterina Ivanova-Todorova
Ekaterina Ivanova-Todorova
EKEkaterina Krasimirova Kurteva
Ekaterina Krasimirova Kurteva
DKDobroslav Kyurkchiev
Dobroslav Kyurkchiev
The central hypothesis for the development of glioblastoma multiforme (GBM) postulates that the tumor begins its development by transforming neural stem cells into cancer stem cells (CSC). Recently, it has become clear that another kind of stem cell, the mesenchymal stem cell (MSC), plays a role in the tumor stroma. Mesenchymal stem cells, along with their typical markers, can express neural markers and are capable of neural transdifferentiation. From this perspective, it is hypothesized that MSCs can give rise to CSC. In addition, MSCs suppress the immune cells through direct contact and secretory factors. Photodynamic therapy aims to selectively accumulate a photosensitizer in neoplastic cells, forming reactive oxygen species (ROS) upon irradiation, initiating death pathways. In our experiments, MSCs from 15 glioblastomas (GB-MSC) were isolated and cultured. The cells were treated with 5-ALA and irradiated. Flow cytometry and ELISA were used to detect the marker expression and soluble-factor secretion. The MSCs’ neural markers, Nestin, Sox2, and glial fibrillary acid protein (GFAP), were down-regulated, but the expression levels of the mesenchymal markers CD73, CD90, and CD105 were retained. The GB-MSCs also reduced their expression of PD-L1 and increased their secretion of PGE2. Our results give us grounds to speculate that the photodynamic impact on GB-MSCs reduces their capacity for neural transdifferentiation.

1 April 2026 in Cancers
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Journal Article
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MMManoela Manova
Manoela Manova
BIBoryana Ivanova
Boryana Ivanova
RKRositsa Krasteva
Rositsa Krasteva
NCNikolay Conev
Nikolay Conev
TZTanya Zlatanova
Tanya Zlatanova
ASAlexandra Savova
Alexandra Savova
Background/Objectives: Small cell lung cancer (SCLC) is a highly metastatic and lethal malignancy. Doublet chemotherapy consisting of a platinum compound and etoposide had remained the standard first-line regimen for decades, particularly for the majority of patients, who are diagnosed with extensive-stage disease. Over the past 5 years, results from the IMpower133 trial led to the approval of anti-PD-L1 agent atezolizumab as part of the first-line regimen for extensive-stage SCLC. The accumulation of real-world evidence on atezolizumab efficacy in this context is essential for corroborating trial results and further improving patient outcomes. Herein, we present real-world evidence from a Bulgarian cohort receiving atezolizumab as part of first-line extensive-stage SCLC treatment, comparing these data to the results of IMpower133. Methods: Data were extracted from the electronic health records of patients receiving atezolizumab plus chemotherapy as first-line treatment for extensive-stage SCLC in the period between 1 January 2022 and 31 December 2024. Analysis was conducted via the Danny Platform, an analytic platform for the integration of real-world evidence using embedded machine learning and LLM algorithms. Patients matching IMpower133 inclusion criteria were included in a group for comparison with trial results. Results: A total of 302 patients were included in the analysis. The real-world progression-free survival (PFS) in our study surpassed that in IMpower133 (7.6 versus 5.2 months), in addition to higher PFS rates beyond six months. A lower Objective Response Rate (ORR) (38.7% versus 65.4%) was noted in our real-world cohort, which we attribute to real-world documentation practices. Conclusions: Real-world evidence regarding PFS and treatment response generally align with the efficacy of adding atezolizumab to first-line extensive-stage SCLC treatment reported in the IMpower133 trial, while reflecting differences that may arise in routine clinical practice.

18 December 2024 in Pharmacia
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Journal Article
Open access
ASAlexandra Savova
Alexandra Savova
BIBoryana Ivanova
Boryana Ivanova
GSGergana Shalamanova
Gergana Shalamanova
IGIva Gavrilova
Iva Gavrilova
JAJeliazko Arabadjiev
Jeliazko Arabadjiev
MMManoela Manova
Manoela Manova
Malignant melanoma is among the leading forms of cancer on a global scale, accounting for 1 in 5 skin cancers. Over the past decades, the treatment of melanoma has significantly improved following the development of therapies such as MAPK molecular therapy targeted at BRAF and MEK signaling pathways. We present real-world evidence from clinical practice in Bulgaria on the treatment of malignant melanoma with dabrafenib and trametinib from 2018 to 2022. Treatment outcomes from the real-world data are compared against the pivotal clinical trials, namely COMBI-d and COMBI-v. Outcomes are compared on the basis of metrics, including overall survival, progression-free survival, and clinical benefit. Further, iterational proportional fitting is performed to control for differences in characteristics across the patient cohorts. Results show that real-world overall survival and progression-free survival outperform results from the clinical trials, particularly with respect to COMBI-d.

20 July 2025 in Expert Review of Pharmacoeconomics & Outcomes Research
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Journal Article
Open access
MMManoela Manova
Manoela Manova
BIBoryana Ivanova
Boryana Ivanova
JAJeliazko Arabadjiev
Jeliazko Arabadjiev
RMRadoslav Mangaldzhiev
Radoslav Mangaldzhiev
ADAssen Dudov
Assen Dudov
ASAlexandra Savova
Alexandra Savova
Third-generation EGFR tyrosine kinase inhibitor (EGFR-TKI) osimertinib is approved as first-line treatment against non-small-cell lung cancer (NSCLC) harboring sensitizing EGFR mutations. Herein, we perform retrospective analysis of real-world data on first-line osimertinib treatment among Bulgarian patients with NSCLC, comparing treatment outcomes to FLAURA results. Patient data were obtained from electronic health records over a 4-year period. Baseline characteristics and endpoints (progression-free survival [PFS], objective response rate [ORR], and clinical benefit rate [CBR]) were compared. Iterative proportional fitting was performed to balance patient characteristics prior to survival analysis. A total of 365 patients on first-line osimertinib were included. Partial responses were more frequent in the RWE cohort (24% vs 13%), while the opposite was noted for stable disease (63% vs 80%). Complete response frequency was comparable (2% vs 1%). The ORR was higher in the real world compared to in FLAURA (26% vs 14%), whereas CBR was slightly higher in the trial (89% vs 94%). The real-world PFS was higher than reported in FLAURA (19.1 vs 18.9 months), with more favorable outcomes in the RWE cohort beyond 18 months. RWE closely aligns with FLAURA results, suggesting even greater benefit of first-line osimertinib in the real-world setting.

13 October 2023 in Pharmacia
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TZTanya Zlatanova
Tanya Zlatanova
JAJeliazko Arabadjiev
Jeliazko Arabadjiev
Both lung carcinoma and idiopathic pulmonary fibrosis (IPF) have an adverse prognosis, and the co-existence of both diseases is not uncommon. We introduce a clinical case involving a patient diagnosed with concurrent occurrences of lung adenocarcinoma and IPF. The patient underwent a therapeutic regimen comprising the administration of docetaxel in conjunction with nintedanib. This treatment approach was followed by the sustained utilization of maintenance nintedanib over an extended duration, leading to substantial enhancements in the patient’s quality of life. Furthermore, we discuss the few therapeutic options concerning this clinical challenge and possible future therapeutic options.

21 May 2026 in Medicina
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JAJeliazko Arabadjiev
Jeliazko Arabadjiev
KNKrasimir Nikolov
Krasimir Nikolov
MKMarchela Koleva
Marchela Koleva
NSNikolay Shopov
Nikolay Shopov
ITIvan Tonev
Ivan Tonev
AKAssia Konsoulova
Assia Konsoulova
Background and Objectives: Although clinically useful, homologous recombination deficiency (HRD) testing has recently been more broadly adopted in ovarian cancer (OC) management. The VALIDATE study evaluated HRD status and treatment patterns in patients with newly diagnosed advanced OC in Bulgaria to better understand HRD prevalence and disease management. Materials and Methods: This real-world, observational, multi-centre, medical chart review study included 100 adult patients with HRD testing results available at study entry. Data collected at least 30 days after HRD results and 6 months later were descriptively analysed in the full cohort and subgroups (HRD, BRCA mutation, and genomic instability score [GIS]). Results: Mean age at diagnosis: 61.3 years; stage III: 51.0%, prevalence of HRD+ 58.0% (95% confidence intervals [CI] 47.7–67.8%) and HRD− 42.0% (95% CI 32.2–52.3%). Among the 58 HRD+ patients, 20 (34.5%) were BRCA+, whereas 38 (65.5%) were BRCA−, and 52 (89.7%) were GIS+, and 6 (10.3%) GIS−. Overall, platinum–taxane chemotherapy plus antiangiogenics was the most common front-line (FL) treatment (77.0%), regardless of subgroups (range: 66.7–85.0%). Six months later, 81 patients were alive, and 73 (90%) started maintenance therapy (MT). Antiangiogenic monotherapy (32.0%) and antiangiogenic plus PARP inhibitor (34.0%) were the most common MTs. The latter was also common across subgroups (range: 33.3–60.5%), except for HRD− (61.9% received antiangiogenic monotherapy). Conclusions: In this dataset, more than half of advanced OC patients had HRD+ status. Our study provides relevant insights into recent clinical practice patterns in advanced OC in Bulgaria that could serve as an anchor for future, more robust research in this field.