Stefan STEWART BALBAS

Dr. Stefan STEWART BALBAS

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Research Focus & Metrics

Academic Career Length

6Years (2021-Present)

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

Representative Publications

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27 September 2021 in Journal of Clinical Medicine
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ADAna Delgado
Ana Delgado
SBStefan STEWART BALBAS
Stefan STEWART BALBAS
MUMikel Urroz-Elizalde
Mikel Urroz-Elizalde
ARAmelia Rodríguez
Amelia Rodríguez
Alberto M BorobiaAlberto M Borobia
Alberto M Borobia
Elena RamírezElena Ramírez
Elena Ramírez
Coronavirus disease 2019 (COVID-19) has a wide spectrum of clinical manifestations. An elevation of liver damage markers has been observed in numerous cases, which could be related to the empirical use of potentially hepatotoxic drugs. The aim of this study was to describe the clinical and analytical characteristics and perform a causality analysis from laboratory signals available of drug-induced liver injury (DILI) detected by a proactive pharmacovigilance program in patients hospitalised for COVID-19 at La Paz University Hospital in Madrid (Spain) from 1 March 2020 to 31 December 2020. The updated Roussel Uclaf Causality Assessment Method (RUCAM) was employed to assess DILI causality. A lymphocyte transformation test (LTT) was performed on 10 patients. Ultimately, 160 patients were included. The incidence of DILI (alanine aminotransferase >5, upper limit of normal) was 4.9%; of these, 60% had previous COVID-19 hepatitis, the stay was 8.1 days longer and 98.1% were being treated with more than 5 drugs. The most frequent mechanism was hepatocellular (57.5%), with mild severity (87.5%) and subsequent recovery (88.1%). The most commonly associated drugs were hydroxychloroquine, azithromycin, tocilizumab and ceftriaxone. The highest incidence rate of DILI per 10,000 defined daily doses (DDD) was with remdesivir (992.7/10,000 DDD). Some 80% of the LTTs performed were positive, with a RUCAM score of ≥4. The presence of DILI after COVID-19 was associated with longer hospital stays. An immune mechanism has been demonstrated in a small subset of DILI cases.

7 November 2024 in BMJ Open
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SBStefan STEWART BALBAS
Stefan STEWART BALBAS
ESEnrique Seco-Meseguer
Enrique Seco-Meseguer
EDELENA DIAGO
ELENA DIAGO
AMAlicia Marín-Candón
Alicia Marín-Candón
MCMontserrat Carmona
Montserrat Carmona
Alberto M BorobiaAlberto M Borobia
Alberto M Borobia
Introduction Genetic variations impact drug response, driving the need for personalised medicine through pre-emptive pharmacogenetic testing. However, the adoption of pre-emptive pharmacogenetic testing for commonly prescribed drugs, such as statins, outside of tertiary hospitals is limited due to a lack of pharmacoeconomic evidence to support widespread implementation by healthcare policy-makers. The Spanish Consortium for the Implementation of Pharmacogenetics (iPHARMGx Consortium) addresses this by developing a clinical trial master protocol that will govern multiple nested adaptive clinical trials that compare genotype-guided treatments to standard care in specific drug–gene–population triads, asses their cost-efficacy and identify novel biomarkers through advanced sequencing techniques. The first of these studies aims to assess whether a pre-emptive statin therapy genotyping scheme reduces the incidence of statin-associated muscle symptoms (SAMS) in a population at risk of cardiovascular disease susceptible of receiving high-intensity or moderate-intensity doses of statins: The PREVESTATGx trial. Methods and analysis the PREVESTATGX trial is a multicentre, adaptive randomised controlled pragmatic phase IV clinical trial nested to the iPHARMGx master protocol with two parallel arms, aiming for superiority. Randomisation will be conducted on an individual basis with a centralised approach and stratification by centre. After inclusion in the trial and genotyping has been performed, subjects will be randomly allocated to experimental group (pharmacogenetic genotype-guided statin prescription) or standard-of-care statin prescription (as deemed by attending physician). The main objective is to assess the efficacy of a statin pre-emptive genotyping strategy in reducing the incidence of SAMS. A total of 225 subjects will be recruited among the 10 participating centres if no futility/efficacy boundary is reached in the prespecified interim analyses. Recruitment will be carried out during a 12-month period and subjects will be followed for a 9-month period. Ethics and dissemination The PREVESTATGx trial received ethical approval on 24 April 2024. Results will be disseminated via publication in peer-reviewed journals as well as presentation at international conferences. Trial results will be submitted for publication in an open-access peer-reviewed medical speciality-specific publication. Trial registration number EU CT number: 2023-509418-12-00/Clinical trial Identifier (ClinicalTrials.gov): NCT06262685. Protocol version 1.2 12 April 2024 (includes non-substantial modification number 14 June 2024). Trial registration of this study can be located at both the EU Clinical Trials Register available from https:// euclinicaltrials.eu/search-for-clinical-trials/?lang=en and https://clinicaltrials.gov. Registration on both websites was done before the enrolment of the first patient complying with European regulations. EU Clinical Trials Register is a primary registry according to the WHO.

29 April 2024 in Journal of Clinical Medicine
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SBStefan STEWART BALBAS
Stefan STEWART BALBAS
AGArturo Gomez
Arturo Gomez
MJMaría Jiménez-González
María Jiménez-González
ACAntonio Javier Carcas-Sansuán
Antonio Javier Carcas-Sansuán
Alberto M BorobiaAlberto M Borobia
Alberto M Borobia
Elena RamírezElena Ramírez
Elena Ramírez
Background: The drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome represents a severe form of drug hypersensitivity reaction characterized by significant morbidity, mortality, and long-term sequelae, coupled with limited therapeutic avenues. Accurate identification of the causative drug(s) is paramount for acute management, exploration of safe therapeutic alternatives, and prevention of future occurrences. However, the absence of a standardized diagnostic test and a specific causality algorithm tailored to DRESS poses a significant challenge in its clinical management. Methods: We conducted a retrospective case–control study involving 37 DRESS patients to validate a novel causality algorithm, the ALDRESS, designed explicitly for this syndrome, comparing it against the current standard algorithm, SEFV. Results: The ALDRESS algorithm showcased superior performance, exhibiting an 85.7% sensitivity and 93% specificity with comparable negative predictive values (80.6% vs. 97%). Notably, the ALDRESS algorithm yielded a substantially higher positive predictive value (75%) compared to SEFV (51.40%), achieving an overall accuracy rate of 92%. Conclusions: Our findings underscore the efficacy of the ALDRESS algorithm in accurately attributing causality to drugs implicated in DRESS syndrome. However, further validation studies involving larger, diverse cohorts are warranted to consolidate its clinical utility and broaden its applicability. This study lays the groundwork for a refined causality assessment tool, promising advancements in the diagnosis and management of DRESS syndrome.

27 April 2025 in Pharmaceuticals
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AGArturo Gomez
Arturo Gomez
SBStefan STEWART BALBAS
Stefan STEWART BALBAS
MUMikel Urroz-Elizalde
Mikel Urroz-Elizalde
JGJavier Guijarro-Eguinoa
Javier Guijarro-Eguinoa
ESEnrique Seco-Meseguer
Enrique Seco-Meseguer
Elena RamírezElena Ramírez
Elena Ramírez
Background/Objectives: Post-market surveillance of COVID-19 vaccines is vital. This study analyzed EudraVigilance data (Jan 2021–Dec 2023) to detect potential safety signals linking COVID-19 vaccines and specific neurological adverse events (aseptic meningitis, Guillain–Barré syndrome, polyradiculoneuropathies, multiple sclerosis, transverse myelitis, neuromyelitis optica). It also explored the impact of non-healthcare professional reports on disproportionality analysis. Methods: EudraVigilance reports were analyzed to quantify neurological events for 5 COVID-19 vaccines and 47 comparators. Disproportionality was assessed using the Proportional Reporting Ratio (PRR). Spearman’s correlation (SCC) was used to examine the impact of non-healthcare professional reports on PRR. Results: An analysis of 4,159,820 COVID-19 vaccine and 114,025 comparator reports showed a reporting decline over time. A higher proportion of adverse drug event reports were submitted by non-healthcare professionals for COVID-19 vaccines compared to control vaccines, a trend observed consistently across 2021 (57.3% vs. 33%, p < 0.001), 2022 (59.4% vs. 36.5%, p = 0.001), and 2023 (42% vs. 24.36%, p = 0.006). In 2023, significant signals (PRR ≥ 2) were found between Jcovden© and polyradiculoneuropathy (PRR 5.4, IC 95% 3.98–7.32), multiple sclerosis (PRR 2.72, IC 95% (1.08–6.87), transverse myelitis (PRR 4.68, IC 95% 1.02–21.35) and neuromyelitis optica (PRR 7.79, IC 95% 3.5–17.37). In addition, both Spikevax© and Comirnaty© showed significant signals with multiple sclerosis (PRR 2.50, IC 95% 1.70–3.68, and PRR 2.33, IC 95% 1.68–3.24) and transverse myelitis (PRR 3.50, IC 95% 1.66–7.50 and PRR 3.58, IC 95% 1.85–6.93). A significant negative correlation between the proportion of reports from non-healthcare professionals and the case/no-case ratio was found (SCC = −0.4683, p = 0.009). Conclusions: While some significant signals emerged in 2023, the combined three-year data showed no vaccine exceeding the PRR threshold of 2. High-quality data and bias mitigation strategies are crucial for accurate PRR estimation in pharmacovigilance and public health.

Verified
Journal Article
Open access
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JGJavier Guijarro-Eguinoa
Javier Guijarro-Eguinoa
SHSara Arjona Hernández
Sara Arjona Hernández
SBStefan STEWART BALBAS
Stefan STEWART BALBAS
OPOlga Pernia
Olga Pernia
PAPedro Arias
Pedro Arias
RRRocío Rosas-Alonso
Rocío Rosas-Alonso
Platin-based chemotherapy is the standard treatment for patients with non-small cell lung cancer (NSCLC). However, resistance to this therapy is a major obstacle in successful treatment. In this study, we aimed to investigate the impact of several pharmacogenetic variants in patients with unresectable NSCLC treated with platin-based chemotherapy. Our results showed that DPYD variant carriers had significantly shorter progression-free survival and overall survival compared to DPYD wild-type patients, whereas DPD deficiency was not associated with a higher incidence of high-grade toxicity. For the first time, our study provides evidence that DPYD gene variants are associated with resistance to platin-based chemotherapy in NSCLC patients. Although further studies are needed to confirm these findings and explore the underlying mechanisms of this association, our results suggest that genetic testing of DPYD variants may be useful for identifying patients at a higher risk of platin-based chemotherapy resistance and might be helpful in guiding future personalized treatment strategies in NSCLC patients.