Julia Romanova

Introduction Chronic cough heavily affects patients’ quality of life, and there are no effective licensed therapies available. Cough is a complication of severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) infection, asthma, and other diseases. Patients with various diseases have a different profile of tussive responses to diverse cough triggers, thereby suggesting sundry mechanisms of neuronal dysfunctions. Previously, we demonstrated that the small molecule drug XC8 shows a clinical anti-asthmatic effect. The objective of the present study was to investigate the effect of XC8 on cough. Methods We studied the antitussive effect of XC8 on cough induced by agonists activating human transient receptor potential (TRP) cation channels TRPA1 or TRPV1 in guinea pigs. We checked the agonistic/antagonistic activity of XC8 on the human cation channels TRPA1, TRPV1, TRPM8, P2X purinoceptor 2 (P2X2), and human acid sensing ion channel 3 (hASIC3) in Fluorescent Imaging Plate Reader (FLIPR) assay. Results XC8 demonstrated clear antitussive activity and dose-dependently inhibited cough in guinea pigs induced by citric acid alone (up to 67.1%) or in combination with IFN-γ (up to 76.4%). XC8 suppressed cough reflexes induced by the repeated inhalation of citric acid (up to 80%) or by cinnamaldehyde (up to 60%). No activity of XC8 against cough evoked by capsaicin was revealed. No direct agonistic/antagonistic activity of XC8 on human TRPA1, TRPV1, TRPM8, P2X2, or hASIC3 was detected. Conclusions XC8 acts against cough evoked by the activation of TRPA1 (citric acid/cinnamaldehyde) but not TRPV1 (capsaicin) channels. XC8 inhibits the cough reflex and suppresses the cough potentiation by IFN-γ. XC8 might be of significant therapeutic value for patients suffering from chronic cough associated with inflammation.

Introduction A significant number of patients with moderate asthma remain symptomatic despite treatment with inhaled corticosteroids (ICS). These patients do not yet meet the criteria for oral corticosteroids (OCS) and monoclonal antibodies. The new anti-chemokine oral drug XC8 could represent an alternative treatment option for these patients. The objective of this trial was to evaluate the effect of different doses of the XC8 in patients with partly controlled asthma in a phase 2a clinical trial. Methods A double-blind, parallel-group, randomized, multicenter, phase 2a trial was conducted at 12 sites in Russia. Patients with asthma were randomized into four groups (n = 30 each) to receive XC8 at 2 mg, 10 mg, 100 mg or placebo once-daily for 12 weeks in addition to low-dose ICS with or without LABA. Efficacy and safety parameters were evaluated at weeks 0, 2, 6, and 12. Results No statistically significant difference between the treatment arms in the number of patients with adverse events was observed. The primary endpoint, improvement of forced expiratory volume in 1 s (FEV₁) % predicted over 12 weeks compared to placebo, was not statistically significant. The treatment of patients with XC8 (100 mg) resulted in statistically and clinically significant improvements in FEV₁ compared to baseline (7.40% predicted, p < 0.001). Patients with elevated peripheral blood eosinophil count (PBEC, > 300 cells/μl) or serum interferon-γ (IFN-γ) level (> 100 pg/mL) treated with XC8 (100 mg) achieved a statistically significant improvement in FEV₁ (11.33% predicted or 8.69% predicted, respectively, p < 0.05) as compared to the baseline versus the placebo. The strongest effect was observed in patients with both high PBEC and IFN-γ level. Pharmacodynamic engagement was demonstrated through the reduction of serum levels of C–C motif ligand 2 (CCL2) and C–X–C motif chemokine 10 (CXCL10). Treatment with XC8 (100 mg) alleviated resistance to maintenance ICS therapy in patients with elevated IFN-γ level. Conclusions Given the high safety, oral route of administration, and efficacy, XC8 may provide a promising treatment option for patients with mild-to-moderate asthma. Trial Registration 795–30/12/2015 (Ministry of Health Russian Federation), NCT03450434 (ClinicalTrials.gov).

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) originated in November 2019 in China and quickly spread throughout the world causing a disease named COVID-19. An analysis of the epidemiological data on morbidity and mortality caused by SARS-CoV-2 shows that, in some countries, namely Belgium, UK, France, Italy, the Netherlands, and Spain, an increased case fatality rate (CFR) was noticed compared to the rest of the world. The CFR, calculated as the number of deaths from the total number of the cases, ranges in these countries from 10.22% to 15.8% according to the Center for Evidence-Based Medicine (CEBM). At the same time, in the countries of Central and Northern Europe, this parameter varies between 3.78% and 4.94%. This significant heterogeneity in CFR between countries has not been given a convincing explanation yet. It was found that the precursor of SARS-CoV-2 is a virus circulating in bats in China. The mutations that occurred in this virus altered its receptor specificity, thereby enabling viral infection in humans. Bats are highly resistant to viral infections due to their robust interferon system and a reduced level of inflammatory reactions. Viruses replicate in these animals up to high titers without any substantial harm to their health. As a result, bats represent a large reservoir of viruses with the potential to infect other animals, including humans. The infection of people with bat (or human) betacoronaviruses can lead to the formation of memory B-cells that provide an accelerated antibody response to cross-reactive epitopes upon subsequent infection. The early emergence of neutralizing antibodies in SARS-CoV-2 patients correlates with the severity of the disease and the likelihood of a fatal outcome. The antibody-dependent enhancement (ADE) of infection/disease known for various viruses, including SARS-CoV-1 and MERS-CoV, may be a possible cause of this phenomenon. In this article, we suggest a close connection between the distribution areas of bats carrying SARS-CoV-1-like viruses and the CFR from COVID-19.

Принята к печати 7 мая 2020 г. Опубликована 14 мая 2020 г. АННОТАЦИЯ Появившись в ноябре 2019 г. в Китае, коронавирус SARS-CoV-2 (severe acute respiratory syndrom-coronavirus 2) быстро распространился по всему миру, вызывая заболевание, получившее название COVID-19. Анализ эпидемиологических данных по заболеваемости и смертности, вызванной SARS-CoV-2, показывает, что в отдельных странах, а именно в Бельгии, Великобритании, Франции, Италии, Нидерландах, Испании, наблюдается повышенная смертность по сравнению с другими странами. Коэффициент летальности, рассчитываемый как число смертельных случаев от общего числа зараженных, по данным Центра доказательной медицины CEBM (Centre for Evidence-Based Medicine), в этих странах составляет от 10.22% до 15.80%. В то же время в Центральной и Северной Европе этот показатель составляет от 3.78% до 4.94%. Причины такой неоднородности в показателе смертности для перечисленных стран пока не получили убедительного объяснения. Установлено, что предшественником SARS-CoV-2 является вирус, циркулирующий в Китае в летучих мышах, в котором произошли мутации, изменившие его рецепторную специфичность и сделавшие возможным инфицирование людей. Летучие мыши обладают высокой устойчивостью к вирусным инфекциям за счет мощной системы интерферонового ответа и сниженного уровня воспалительных реакций. Вирусы реплицируются в этих животных до высоких титров, не принося существенного вреда их здоровью. В результате огромное множество существующих в природе летучих мышей является переносчиком вирусов, заражая животных и людей. Заражение людей бетакоронавирусами летучих мышей (или человека) может приводить к образованию у них В-клеток памяти, которые обеспечивают ускоренный антительный ответ к перекрестным эпитопам при последующей инфекции. Раннее появление антител у больных SARS-CoV-2 коррелирует с тяжестью патологии и вероятностью летального исхода. Возможной причиной этого явления может быть реакция антителозависимого усиления инфекции/заболевания ADE (antibody-dependent enhancement), известная для различных вирусов, включая SARS-CoV-1 и MERS-CoV. В данной статье мы предполагаем наличие связи между ареалами распространения летучих мышей, являющихся переносчиками SARS-CoV-1-родственных вирусов, и уровнем смертности при COVID-19.

XC8 (histamine glutarimide) is a non-steroidal anti-inflammatory anti-bronchoconstriction agent which targets eosinophilic migration and mast cell degranulation by inhibition of chemokines (CCL2, CCL7, CCL8, CCL13). Previous animal studies have shown beneficial effects of XC8 on airway inflammation. The primary objective of this double-blind placebo-controlled multi-center dose-escalating phase-1 study was to assess the safety of oral XC8. The secondary objective was evaluating the pharmacokinetics (PK). The study population consisted of 32 healthy female (47%) and male adults. Three dose-escalation cohorts (10 mg [n=8], 50 mg [n=8] and 200 mg [n=16]) in two centers were randomized in a 3:1 ratio. The subjects received a single dose at Day 1 and then once-daily for 14 days (Days 8-21). Safety data was collected until Day 36. PK data were collected before (Days 1 and 8-21) and 20 min, 30 min, 1, 2, 4, 8 and 24h after (Days 1 and 21) the administration of the investigational product, respectively. No severe adverse events (AE) occurred. No AEs led to study discontinuation, all subjects completed the study as planned. AEs were not increased in the treatment arms compared to placebo. No clinically significant changes occurred in the safety laboratory in subjects receiving XC8. The PK data showed similar dose and time dependent mean plasma XC8 concentrations both after single (Day 1) and multiple (Day 21) dosing. The median time to maximum plasma concentration was 0.68-1.01 hours after single and 0.67-0.98 hours after multiple dosing. There was no evidence for accumulation of XC8 and it showed linear PK. XC8 was safe and well tolerated. A phase 2 study will be performed to further evaluate the potential role of XC8 in asthma treatment.

Background: Corticosteroids are the preferred option to treat asthma, however, they possess serious side effects and are inefficient in 10% of patients. Thus, new therapeutic approaches for asthma treatment are required.Objective: To study the efficacy of a novel glutarimide derivative XC8 in a Sephadex-induced lung inflammation in rats as well as in acute and chronic ovalbumin-induced allergic asthma in guinea pigs.Method: Rats were treated with 0.18-18 mg/kg of XC8 intragastrically 4 times (24 h and 1 h prior to and 24 h and 45 h after endotracheal administration of Sephadex). The number of inflammatory cells in bronchoalveaolar lavages (BAL) was determined. Guinea pigs were treated with 0.045 -1.4 mg/kg (acute asthma) or with 1.4 and 7.0 mg/kg of XC8 (chronic asthma) intragastrically following the sensitization with ovalbumin and during aerosol challenge. Lung inflammation, numbers of eosinophils (BAL and lung tissue), goblet cells, degranulating mast cells and specific airway resistance (sRAW) were determined. The comparator steroid drug budesonide (0.5 mg/kg for rats and 0.16 mg/kg for guinea pigs) was administered by inhalation.Results: XC8 reduced influx of eosinophils into BAL in Sephadex-induced lung inflammation model in rats (by 2.6-6.4 times). Treatment of acute asthma in guinea pigs significantly reduced eosinophils in guinea pigs in BAL (from 55% to 30%-39% of the total cell count) and goblet cells in lung tissue. In a model of acute and chronic asthma, XC8 reduced significantly the number of eosinophils and degranulating mast cells in the lung tissue. Treatment with XC8 but not with budesonide decreased the specific airway resistance in acute and chronic asthma model up to the level of naive animals.Conclusion: XC8 induced a profound anti-inflammatory effect by reducing eosinophils in BAL and eosinophils and degranulating mast cell numbers in the airway tissue. The anti-asthmatic effect of XC8 is comparable to that of budesonide. Moreover, in contrast to budesonide, XC8 was capable to reduce goblet cells and airway resistance.

In order to decrease the morbidity and mortality caused by seasonal influenza outbreaks, several hundred million vaccine doses are produced worldwide each year. The predominant substrate for the production of the influenza vaccine today is fertilized hen’s eggs. The substitution of the technology based on living organisms by the cell culture-based process offers many advantages, including easier scalability and reduced dependence on the availability of eggs. The African green monkey kidney and Madin Darby canine kidney cell lines support the efficient growth of influenza viruses of different subtypes and, therefore, are considered to be the two most promising alternative substrates for the production of the human influenza vaccine. However, the pH of endosomes in both of these cell lines is higher than the pH essential for triggering a conformational change of the hemagglutinin (HA) of human influenza viruses, which enables the viral-cellular membrane fusion. This mismatch gives rise to mutations in the HA that lead to an increase of the optimum pH of HA conformational change. As of a result of these mismatches, the HA, and consequently the whole virus, has reduced stability to low pH and elevated temperatures. The production of a vaccine from less stable virus will lead to an elevated HA content in the low pH conformation that can affect the safety, potency, infectivity, and protective efficacy of the final inactivated and live attenuated influenza vaccines. The main limitations of the cell line-based influenza vaccine technology and the possibilities to preserve the viral stability over the course of influenza vaccine production are discussed in the review.