Inspections of pharmaceutical market participants to verify their compliance with good practice requirements are integral to good regulatory practices of the Member States of the Eurasian Economic Union (EAEU). The framework for Good Clinical Practice (GCP) inspections is outlined in Decision No. 78 of the Council of the Eurasian Economic Commission of November 3, 2016.

This interview with Alla A. TRAPKOVA, Deputy General Director of the Scientific Centre for Expert Evaluation of Medicinal Products of the Ministry of Health of the Russian Federation, provides information on the importance, objectives, and rules of conducting GCP inspections.

Drug-induced liver injury (DILI) is the reason for 15–18% of medicinal product recalls from the market. Since interspecies differences often limit the relevance of standard non-clinical tests in vivo, a promising alternative is to develop cell-based in vitro methods.

The aim of the study was to review current advances in cell modelling for the in vitro identification of DILI.

In vitro mechanistic studies of DILI require cells that exhibit activity specific to hepatic metabolising enzymes and transporters. This article reviews the main cell cultures (primary human hepatocytes, immortal cell lines, stem cell-derived hepatocyte-like cells, co-cultures of hepatocytes and non-parenchymal liver cells) and their configurations. The optimisation of cell systems is directed towards enhancing their viability, functionality, compositional and configurational complexity, thus bringing them closer to in vivo models. Potential DILI causes include chemically reactive metabolites, oxidative stress, mitochondrial damage, intracellular accumulation of toxic bile acids resulting from transporter inhibition, and adaptive immune system activation. Accordingly, DILI studies rely on various methods, including innovative technologies for acquisition, storage, and analysis of large datasets (e.g. high-content screening, transcriptomics, proteomics, and metabolomics). Cell models are applicable to both DILI identification and mechanistic studies. Currently, the most promising technologies are omics, complex co-culture models, and organ-on-a-chip systems.

High dose selection is a key methodological element in general toxicity studies of medicines. It determines the informative value of study results, the compliance with the principles of ethical and rational use of experimental animals, and the accuracy of predicting the safety of new medicines for human use. The literature data and the regulatory experience in evaluating preclinical study results suggest that the selection of an inappropriate high dose is a very common error in planning toxicity studies. This error leads to a significant or complete loss of the informative value of study results; the results become useless for assessing the safety of new medicinal products for human use.

The aim of this study was to analyse the current regulatory requirements for high dose selection for general toxicity studies of medicines.

The analysis suggests that unreasonably high doses may be selected for toxicity studies because methodological recommendations are prone to interpretation errors. Their potential for ambiguity stems from the absence of specific standardised upper limits for toxic doses or sufficiently clear dose selection criteria. Prerequisites for properly planning preclinical safety studies of new medicines include compliance with dose selection requirements of regulatory toxicology and implementation of a clinically and toxicologically sound decision-making algorithm.

Researchers need to identify the nephrotoxic properties of medicinal products both during preclinical development and when exploring options to optimise pharmacotherapy. The main challenge is to find an experimental model for assessing drug-induced nephrotoxicity that reflects in vivo conditions as closely as possible.

The aim of the study was to compare the susceptibility of HEK293 and RPTEC cell lines used as experimental models for assessing the nephrotoxicity of cefuroxime and cefepime.

Materials and methods. The study investigated HEK293 and RPTEC cell lines cultured on plates with 0.4 µm pore membrane inserts. The cell lines were incubated for 3 days with cefuroxime and cefepime (cephalosporins excreted primarily by the kidneys). The medicinal products were added to the basal part of the well at concentrations of 50 and 150 µg/mL (cefuroxime) or 30 and 120 µg/mL (cefepime) twice a day. After incubating the cells with cefuroxime and cefepime for 24, 48, and 72 hours, the authors determined the expression levels of the SLC22A6 and SLC22A8 genes encoding organic anion transporters by a reverse transcription polymerase chain reaction. The authors considered caspase 3 and caspase 7 activation indicative of the nephrotoxic effect of cephalosporins; they evaluated this indicator by a fluorometric assay after 24, 48, and 72 hours of incubation.

Results. According to the study, the expression of the SLC22A6 and SLC22A8 genes decreased with cephalosporin transport in both cell lines. The decrease occurred in the RPTEC cell line earlier than in the HEK293 cell line. The authors observed caspase 3 and caspase 7 activation only in the RPTEC cell line after incubation with cefuroxime and cefepime at low concentrations (50 and 30 µg/mL, respectively) for 72 hours and at high concentrations (150 and 120 µg/mL, respectively) for 24 hours.

Conclusions. The RPTEC cell line exhibits higher susceptibility to cefuroxime and cefepime toxic effects than the HEK293 cell line due to higher transporter gene expression. Higher cephalosporin concentrations accelerate caspase 3 and caspase 7 activation in the RPTEC cell line. The experimental model based on the RPTEC cell line is a promising tool for the analysis of the nephrotoxic properties of a wide range of medicinal products.

Most of the medicinal products that are currently approved and used in clinical practice for neurodegenerative diseases, in particular Alzheimer’s disease, have a compensatory mechanism of action that enhances neurotransmitter signalling. It is an urgent need to develop new medicinal products combining cognitive-enhancing, neuroprotective, and disease-specific effects resulting from a multi-target mechanism of action including, in particular, prevention of glutamate-induced neuronal calcium uptake and stabilisation of microtubules.

The aim of this study was to search for potentially neuroprotective and tauopathy-alleviating medicines amongst new thiouronium salt derivatives based on vicinal diamines.

Materials and methods. The study investigated the ability of thiouronium salts to block glutamate-induced ⁴⁵Ca²⁺ uptake by synaptosomes prepared from the brain of Wistar rats. The authors evaluated effects of these new compounds on polymerisation of a preparation of C57bl mouse brain tubulin and microtubule-associated proteins. The evaluation was carried out in the presence of guanosine triphosphate (GTP) and based on specific absorbance changes at 355 nm due to formation of microtubules. The authors analysed the structure of these microtubules, using negative staining followed by transmission electron microscopy. The IC₅₀ determination and the statistical analysis were performed using standard software (Excel and PRISM 6.02).

Results. The authors developed a screening algorithm for a number of new thiouronium salt derivatives based on vicinal diamines and studied biological activity of these derivatives by the effects on glutamate-induced calcium uptake by synaptosomes and on microtubule assembly processes. The authors identified compounds suppressing glutamate-induced calcium uptake by synaptosomes, i.e. compounds with neuroprotective potential. In addition, a number of new compounds were able to stimulate GTP-dependent microtubule assembly processes. The authors observed formation of microtubules with a normal structure in the presence of isopropyl-N’-[2-(benzoylamino)-1,2-diphenylethyl]-N-ethylimidothiocarbamate hydrobromide and considered the compound a promising scaffold for further optimisation.

Conclusions. Chemical modification of thiouronium salts is a promising direction for developing effective neuroprotectors and microtubule stabilisers. 

Esomeprazole, the S-isomer of omeprazole, is a second-generation proton pump inhibitor widely used for acid-related diseases of the oesophagus, stomach, and duodenum (peptic ulcer, gastro-oesophageal reflux disease, etc.). Studies on esomeprazole safety and toxicokinetics (TK) are essential for increasing the number of modified-release esomeprazole products manufactured in Russia.

The aim of the study was to compare the safety and toxicokinetics of a new esomeprazole product, 40 mg modifiedrelease capsules (Valenta Pharm JSC, Russia), and Nexium^® 40 mg film-coated tablets (AstraZeneca AB, Sweden).

Materials and methods. This toxicity study involved oral administration of esomeprazole 40 mg modified-release capsules (Valenta Pharm JSC, Russia) and Nexium^® 40 mg film-coated tablets (AstraZeneca AB, Sweden) to 5 groups of rabbits (8 males and 8 females per group) for 28 days at a dose of 1 or 3 capsules, or tablets, corresponding to approximately 4.8 or 14.3 maximum human therapeutic doses (MHTDs), respectively. Comparisons included general toxicity, local tolerance, safety pharmacology, effects on immune system organs, reproductive toxicity, and basic TK parameters (C_max, T_max, AUC_0-24, MRT, and T_1/2).

Results. No toxic effects, including local irritation and immunotoxicity, were observed for the test product. The safety pharmacology testing demonstrated the safety of repeated oral administration of the test product for the cardiovascular, excretory, respiratory systems and the liver. The test product did not affect the reproductive system of male and female rabbits. The No Observed Adverse Effect Level (NOAEL) was determined to be 14.3 MHTDs. According to the TK parameters evaluated after single and repeated oral administration, the test product and Nexium^® demonstrated comparable TK profiles.

Conclusions. The study demonstrated a favourable safety profile for the test product. All the test product parameters studied were comparable with those of Nexium^®. Positive clinical experience with Nexium^® supports the data obtained for the new esomeprazole product. Thea safety of these medicinal products may be considered similar.

Several treatment regimens with antituberculosis medicinal products are available for tuberculosis. Thiozonide is a newly developed original antimicrobial agent that exhibits bacteriostatic activity against Mycobacterium tuberculosis strains H37Rv, CN-37, CN-40, and MS-115.

The aim of the study was to investigate the embryotoxic, foetotoxic, and teratogenic effects of thiozonide in pregnant rabbits.

Materials and methods. The study involved 66 pregnant rabbits (4 groups of 16–17 animals each). The rabbits received oral thiozonide from day 6 to day 19 of gestation at doses of 20.6 mg/kg (1 TD (therapeutic dose)), 103 mg/kg (5 TDs), and 206 mg/kg (10 TDs). The control group received a 1% starch solution. The authors conducted a macroscopic examination of the reproductive organs and a histological evaluation of the placenta in eutha nised pregnant rabbits. Live foetuses underwent a check for developmental abnormalities, a skeletal development evaluation with a modified Dawson’s method, and a histologic examination of the internal organs.

Results. The study showed no clinical signs of toxicity and no mortality associated with thiozonide in pregnant rabbits across all dose groups. Macroscopic and histological examinations revealed no pathological changes in the reproductive organs of pregnant rabbits. The evaluation of embryotoxic and foetotoxic effects did not identify any differences between the foetuses of the animals assigned to different doses of thiozonide and the control group. The authors found no developmental abnormalities in the foetuses. Examinations of foetal skeleton development and internal organ condition identified no differences between the groups and no abnormalities. The authors registered the death of all foetuses (late resorption) in one rabbit from the 206 mg/kg group. Therefore, the 103 mg/kg dose (5 TDs) was selected as a reasonable No Observed Adverse Effect Level (NOAEL).

Conclusions. Thiozonide has no embryotoxic, foetotoxic, or teratogenic effects.

Idiosyncratic drug-induced liver injury (iDILI) is a rare and poorly predictable adverse drug reaction that may lead to death or liver transplantation in severe cases.

The aim of the study was to review contemporary concepts of the immune-mediated pathogenesis of iDILI and possible ways to predict and prevent the risk of developing this condition.

The liver is characterised by high immune tolerance due to a complex of mechanisms involving various cells (antigen-presenting cells, T-cells), cytokines, and other molecules, which prevents severe immune responses to xenobiotics entering the body. Previous research has shown that iDILI results from a combination of multiple synergistic unfavourable factors that impair liver immune tolerance at different levels. These factors include the hepatotoxicity-associated chemical properties of medicines and the individual characteristics of the patient, including the genetically determined structure and function of the adaptive immune system components. Since iDILI has a multilevel and multifactor pathogenesis, it is difficult to determine a risk biomarker for a particular medicine. According to the literature review, the risk of hepatotoxicity of a drug candidate and/or a metabolite can be reduced at the preclinical level by assessing the ability to cause mitochondrial damage, form non-covalent bonds, produce reactive oxygen species, and release damage-associated molecular patterns (DAMPs). The association of iDILI with gene polymorphisms in patients receiving certain medicines has a high negative predictive value and can be used in clinical practice to rule out iDILI or identify hepatotoxic medicinal products in polypharmacy. The identification of the allele combinations associated with an increased risk of iDILI seems promising for enhancing the predictive value of genetic studies and may be used in personalised medicine.

In recent years, there has been a significant increase in the number of patients with malignancies treated with immune checkpoint inhibitors (ICIs), including the anti-programmed cell death protein 1 (anti–PD-1) agent pembrolizumab. One of the important aspects of conducting clinical trials with ICIs is the assessment of the risk of developing immune-related adverse events (irAEs).

The aim of the study was to evaluate the safety of a pembrolizumab biosimilar (BCD-201, Pembroria) compared with a reference medicinal product using the results of a phase I clinical trial and the available medical literature.

Materials and methods. A phase I double-blind, randomised, controlled clinical trial (BCD-201-1) has been conducted in patients with advanced melanoma and non-small-cell lung cancer (n=131). Patients were randomly allocated in a 1:1 ratio to receive either BCD-201 (Pembroria) or the reference medicinal product (Keytruda®), administered intravenously at a dose of 200 mg every 3 weeks for up to 24 weeks or until disease progression or unacceptable toxicity is observed. Since the trial results remain blinded at the time of this writing, treatment group data are masked.

Results. The study demonstrated the equivalence of pharmacokinetics and comparable safety profiles of pembrolizumab biosimilar and reference medicinal products. Both medicinal products were well tolerated; the frequency of all-grade irAEs was comparable between treatment groups (21.2% in Group 1 vs 21.5% in Group 2). Most irAEs were mild to moderate, with the exception of a case of Grade 3 diarrhoea and immune-mediated enterocolitis in one study subject; there were no statistically significant differences in the median time to development of irAEs between treatment groups (Р=0.22, two-sided Wilcoxon test).

Conclusions. The analysed period of the BCD-201-1 trial demonstrated comparable safety characteristics of Pembroria and Keytruda®, which is consistent with the published safety data on the latter. Information on the similarity of long-term safety profiles of the pembrolizumab biosimilar and the reference medicinal product will be obtained from ongoing clinical trials.

Angiotensin-converting enzyme inhibitors (ACEIs) are among the most prescribed and effective medicinal products for the treatment of several cardiovascular diseases. According to a number of studies, 30% of patients taking ACEIs develop adverse drug reactions (ADRs), and treatment discontinuation is often required as a result. The most common ADR associated with ACEIs is a dry (non-productive) cough. Nevertheless, the clinical signs and medical history predictive of this ADR in cardiovascular patients are still understudied.

The aim of the study was to analyse the clinical signs and medical history predictive of cough in patients with cardiovascular conditions treated with enalapril.

Materials and methods. The study was carried out in 2019–2022 and enrolled 224 patients with essential hypertension (grades 2 and 3) treated with enalapril at a dose of 10–20 mg/day. The patients were assigned to 2 groups: Group 1 included 113 patients with enalapril-associated cough, while Group 2 (control group) comprised 104 patients without this ADR. At screening, all the patients underwent a general examination and a check of their allergy and medication history. Using the data obtained, the authors analysed the association of the clinical signs and medical history with the ADR of interest (dry cough).

Results. In contrast to the control group, the group with ACEI-associated dry cough included more patients with a history of drug-induced toxicoderma (OR=5.639, CI 2.234–14.236, χ²=15.845, and p<0.001) or type 2 diabetes mellitus (OR=3.409, CI 1.461–7.953, χ²=8.7472, and p<0.01), a family history of bronchial asthma (OR=4.141, CI 2.066–8.299, χ²=17.417, and p<0.001), and a close family history of severe allergic reactions (OR=3.714, CI 1.720– 8.018, χ²=12.137, and p<0.001).

Conclusions. A family history of allergy increases the probability of dry cough in patients taking ACEIs. In order to improve the safety of ACEI therapy, patients with cardiovascular conditions should be asked more detailed questions about their personal or first-degree family history of allergy.