The coronavirus (COVID-19) pandemic, which began in 2020, has affected all spheres of life, including clinical trial processes. Health authorities around the world issued recommendations aimed at minimising the risks of virus spreading and ensuring the safety of study participants. One of the types of clinical trials is bioequivalence studies of generic medicines. The aim of the study was to analyse current foreign approaches to planning and conduct of bioequivalence studies of medicines in the context of the COVID-19 pandemic, and to develop recommendations for planning of studies conducted in the Eurasian Economic Union and evaluation of their results. The paper discusses the main provisions of the current guidelines of the European Medicines Agency (EMA) and the US Food and Drug Administration (FDA) on the planning, conduct and evaluation of clinical trials and, in particular, bioequivalence studies of generic medicines. The paper substantiates the necessity of detailing the recommendations of the Ministry of Health of the Russian Federation, published in an open letter to all market stakeholders and regulating the conduct of clinical trials of medicines in the context of the coronavirus pandemic. The results of the analysis helped to develop recommendations aimed at ensuring the protection of clinical trial participants, as well as maintaining an acceptable level of quality and reliability of study results.
Today, within the context of harmonisation of requirements in the international pharmaceutical market, there is a trend towards development of common standards, including in the field of preclinical studies. The reliability and reproducibility of experimental data obtained in various laboratories using animals cannot be guaranteed unless the 3Rs principles are observed (the principles of humane experimental technique) to ensure the welfare of animals. The present paper analyses Russian and foreign recommendations on different administration routes and administered volumes as applied to mice, rats, guinea pigs, and rabbits – the most frequently used laboratory animals. The paper systematises literature data on oral/intragastric, subcutaneous, intramuscular, intravenous and intraperitoneal routes of administration. It assesses potential complications of each route of administration, and negative effects on both health and well-being of laboratory animals, as well as on the results of experiments. The paper also touches upon some anatomical and physiological characteristics of laboratory animals, potential opportunities for feed and water deprivation, ways of reducing pain in animals. The results of comparison of administered volumes helped to determine optimal recommended and maximum administered volumes.
Criteria for evaluation of clinical efficacy make it possible to assess the risk-benefit ratio of anticancer medicines that patients receive, in particular, for the treatment of solid malignant tumors. A medicine’s efficacy is assessed using special criteria called the endpoints of clinical efficacy, allowing most objective assessment of study results. It was demonstrated that nowadays clinical efficacy of anticancer drugs is assessed using «patient-centered» (overall survival and quality of life) and «tumor-centered» (response to therapy, progression-free survival, disease-free survival) endpoints. «Patient-centered» endpoints make it possible to evaluate the direct clinical benefit of chemotherapy in patients, while «tumor-centered» endpoints allow for evaluation of efficacy at earlier stages, without directly reflecting the clinical benefit. The analysis of the most suitable endpoints with the aim of making them interchangeable with the primary outcome measure – overall survival – is becoming more and more relevant in oncology. The choice of criteria of efficacy should be made taking into account the specific features of a particular oncological disease, study population and duration of therapy. The authors of the study analysed Russian and foreign literary sources containing information on criteria of efficacy of anticancer medicines and highlighted the advantages and disadvantages of these criteria. The study showed that clinical endpoints should be clinically significant, sensitive to therapy, easy to measure and interpret. It was demonstrated that comprehensive evaluation of outcome measures makes it possible to adequately assess the risk-benefit ratio of anticancer medicines.
Neurotoxic effects are one of the common reasons for discontinuation of preclinical and/or clinical studies. Preclinical evaluation of neurotoxic effects is complicated due to a wide range of manifestations and degrees of severity. Current experimental approaches to neurotoxicity assessment are cumbersome, laborious and not adapted enough for preclinical studies in the early stages of drug development. The aim of the study was to review existing approaches to experimental assessment of neurotoxic potential of new drugs and to discuss the need for and feasibility of developing and using integrated rapid neurotoxicity tests for early assessment of a pharmacological project’s potential. The authors reviewed scientific literature and guidance documents and analysed current approaches to chemical compound neurotoxicity assessment in laboratory animals. The paper analyses the main issues of neurotoxicity assessment for new drugs and compares Irwin tests with the functional observation battery. It analyses issues related to assessment of drugs’ effects on the development and maturation of central nervous system functions at pre- and postnatal stages. It was determined that the current practice is not sufficient for assessment of potential adverse effects on cognitive functions. The authors assessed factors affecting cognitive functions of rodents during studies. The “Acute suppression of the exploratory and orientation response” and “Extrapolation escape task” tests were proposed for validation as potential rapid tests for detection of an array of organic and functional neurotoxic disorders at early stages of preclinical studies.
The work is a continuation of the research on the use of NMR spectroscopy in the quality control of natural peptide hormone-based active substances and their synthetic analogues.The aimof the paper was to develop identification test methods for triptorelin acetate and goserelin acetate substances using NMR spectroscopy that does not require reference standards ‒ with the aim of using the newly developed test methods in pharmacopoeial analysis.Materials and methods:the procedure was developed using two-dimensional NMR spectroscopy (1H-1H gCOSY,1H-13C gHSQC,1H-13C gHMBC).Results:thestudy made it possible to assign1H and13C NMR signals to a specific molecular fragment, and to determine the amino acid composition of each oligopeptide.Conclusions:the authors drew up a table showing structural assignment of NMR signals, which makes it possible to use the NMR method for identification testing of triptorelin acetate and goserelin acetate substances without the use of pharmacopoeial reference standards. The study helped to determine the optimal temperature conditions for recording13C NMR spectra (27 °С and 50 °С for triptorelin acetate and goserelin acetate, respectively). It was demonstrated that13C NMR spectroscopy could be used for identification testing in pharmacopoeial analysis.
The article examines the role of ubiquinone as a redox molecule whose functions consist in electron transport in the mitochondrial respiratory chain and regeneration of endogenous antioxidants. Changes in electron redox pathways cause uncontrolled release of reactive oxygen species, which leads to oxidative stress and development of pathologies. The objective of the study was to determine the content of coenzyme Q10 and its redox status in the human body as a biomarker of oxidative stress in various pathologies. This was achieved by assessing and consolidating data on changes in concentrations of the oxidized, reduced ubiquinone forms and total ubiquinone in various pathologies. Total serum ubiquinone was reduced in patients with chronic heart failure (0.68 μmol/L) compared with the control group (0.97 μmol/L). The redox status, expressed as the [ubiquinol]/ [ubiquinone] concentration ratio, decreased in patients with coronary heart disease (0.49 ± 0.34), diabetes (0.26 ± 0.16) compared with the healthy subjects (1.23–1.41). A negative correlation with malonic dialdehyde was observed. The authors analysed the possibility of assessing the efficacy of statin therapy by plasma ubiquinone concentration in patients. Patients with hyperlipidemia who received statins showed a statistically significant reduction in ubiquinol concentration after taking the drug (from 0.81 to 0.46 μg/mL) and the [ubiquinone]/[total ubiquinone] ratio (from 11 to 10 %), which confirms the potential mechanism of statinassociated muscle injury development. Thus, coenzyme Q10 redox status, as well as the concentrations of oxidized, reduced and total ubiquinone can be effective biomarkers of oxidative stress in cardiovascular diseases, diabetes, as well as an important indicator in evaluating the efficacy of hyperlipidemia treatment.
The decoding of the DNA structure and development of new molecular methods of its analysis, as well as identification of specific genomic changes responsible for malignant transformation, have become the turning points in elaboration of novel anti-tumour drugs directed against molecular and genetic targets of tumor growth. Transition from empirical screening of agents inhibiting tumour cell proliferation to molecule-targeted analytical methods has raised a number of serious methodological issues regarding preclinical evaluation of novel medicines. The objective of this paper was to analyse general principles and features of preclinical efficacy and safety studies of different classes of modern anti-tumour drugs with a view to improve existing national guidelines. The paper reviews various aspects of preclinical studies of different classes of anti-tumour drugs (small molecule chemotherapy drugs, hormones and hormone antagonists, alkylating agents and antimetabolites, microbial and herbal medicines, as well as monoclonal antibodies). The article explores general principles of studying the drugs’ pharmacological activity in vitro, ex vivo, and in vivo, and evaluating their pharmacokinetic parameters. It describes various methods and models of research, summarises specific aspects of determination of genotoxicity, carcinogenicity, reproductive toxicity, mutagenicity, acute and chronic toxicity of various groups of medicines. It also lists criteria for selecting drug doses for toxicokinetic studies. The need for harmonisation of national requirements for conducting preclinical studies with the European standards entails alignment of terminology and further development of general algorithms for selecting doses and determining the necessary scope of research. The use of biomarkers in preclinical studies will make it possible to exclude inefficient compounds from further research.
The State Pharmacopoeia of the Russian Federation, 14th edition states that implants are a sterile dosage form, and have to be tested for pyrogens. However, it does not provide details on how the test should be performed for this dosage form.The aim of the study was to develop a LAL test procedure for detection of bacterial endotoxins (BE) in implants, using the example of a goserelin product.Materials and methods: BE extraction from the implant surface into an aqueous medium was performed with subsequent BE detection in the extract by turbidimetric kinetic test. The implant was then dissolved in dimethyl sulfoxide, and the obtained goserelin solution was tested for BEs using the gel-clot test.Results: the analysis of the Russian and foreign pharmacopoeial approaches to pyrogenic substance detection in hormonal implants helped to develop two sample preparation procedures for determination of BE content (in the extract and the implant solution). It was demonstrated that the BE content in the water extract did not exceed 0.01 EU/mL and was less than 0.07 EU per implant. The BE content in the implant solution was less than 8.3 EU per 1 mg of goserelin, which is almost eleven-fold lower than the theoretically-derived limit.Conclusions: the authors developed two test procedures for BE detection in hormonal implants using the LAL test, which could be included in manufacturers’ product files. The first procedure involves testing of the water extract from the implant surface and establishes the BE limit of no more than 20 EU/product. The second procedure involves complete dissolution of the implant in dimethyl sulfoxide and establishes the limit of not more than 97.22 EU per 1 mg of goserelin.