Remdesivir: A Closer Look at Its Effect in COVID-19 Pandemic

Meeting report: Seventh summer school on innovative approaches for identification of antiviral agents (IAAASS)

The 7th Summer School on Innovative Approaches for the Identification of Antiviral Agents (IAAASS) was held at the Sardegna Ricerche Research Park in Santa Margherita di Pula, Sardinia, Italy from September 23-27, 2024, organized by the Co.S.Me.Se, the Department of Life and Environmental Sciences of the University of Cagliari and Sardegna Ricerche in the frame of Next Generation Virology initiative and the Antiviral DiscoVery Initiatives: Educating Next-Gen Scientists (ADVISE Project) 2024. The Summer School is proposed as an informal high-level event comprehensive of the different scientific souls involved in the design and development of new antiviral drug-candidates and their validation and progression up-to the clinic, and it offers, to a limited number of early career scientists, high-level lectures, networking and mentoring opportunities by internationally recognized scientists in a highly interactive environment. The meeting was a very successful event that convened 21 senior speakers with internationally recognized experience in the field of antiviral research and 60 Early Career Scientists (graduated master students, PhD students and early post doctoral researchers) from 13 different countries (Belarus, Belgium, Brazil, Bulgaria, Chile, Denmark, Germany, Italy, Russian Federation, Spain, Switzerland, The Netherlands, and the USA).

Green synchronous spectrofluorimetric analysis of remdesivir, the first approved antiviral, with levodropropizine as add-on therapy for covid-19: application in their pharmaceutical dosage form, and spiked human plasma

It was the first time that a spectrofluorimetric approach for the simultaneous analysis of remdesivir and levodropropizine had been achieved. This study aims to propose an accurate and sensitive second-derivative synchronous spectrofluorimetric approach for measurement of remdesivir and levodropropizine in different matrices simultaneously without the need for prior separation. The proposed approach measured the synchronous fluorescence intensity of pharmaceuticals under research at a constant wavelength difference (Δλ) = 130 nm. For the quantitative analysis of remdesivir and levodropropizine, the peak amplitudes of the second derivative were measured at 390 and 399 nm, respectively. The procedure was completely validated and demonstrated outstanding linearity in the concentration ranges of 5-150 ng mL- 1 and 10-600 ng mL- 1 for remdesivir and levodropropizine, respectively. The new method was used to quantitatively analyze both drugs in their pharmaceutical dosage form, synthetically formulated mixture and spiked human plasma. A statistical comparison of the results with other published analytical techniques revealed no significant difference. The validation of the procedure was successfully completed in compliance with ICH guidelines. In terms of greenness, EcoScale and GAPI greenness tools were used to evaluate the analytical methodology.

Investigation of the mutated antimicrobial peptides to inhibit ACE2, TMPRSS2 and GRP78 receptors of SARS-CoV-2 and angiotensin II type 1 receptor (AT1R) as well as controlling COVID-19 disease

SARS-CoV-2 is a global problem nowadays. Based on studies, some human receptors are involved in binding to SARS-CoV-2. Thus, the inhibition of these receptors can be effective in the treatment of Covid-19. Because of the proven benefits of antimicrobial peptides (AMPs) and the side effects of chemical drugs, they can be known as an alternative to recent medicines. RCSB PDB to obtain PDB id, StraPep and PhytAMP to acquire Bio-AMPs information and 3-D structure, and AlgPred, Toxinpred, TargetAntiAngio, IL-4pred, IL-6pred, ACPred and Hemopred databases were used to find the best score peptide features. HADDOCK 2.2 was used for molecular docking analysis, and UCSF Chimera software version 1.15, SWISS-MODEL and BIOVIA Discovery Studio Visualizer4.5 were used for mutation and structure modeling. Furthermore, MD simulation results were achieved from GROMACS 4.6.5. Based on the obtained results, the Moricin peptide was found to have the best affinity for ACE2. Moreover, Bacteriocin leucocin-A had the highest affinity for GRP78, Cathelicidin-6 had the best affinity for AT1R, and Bacteriocin PlnK had the best binding affinity for TMPRSS2. Additionally, Bacteriocin glycocin F, Bacteriocin lactococcin-G subunit beta and Cathelicidin-6 peptides were the most common compounds among the four receptors. However, these peptides also have some side effects. Consequently, the mutation eliminated the side effects, and MD simulation results indicated that the mutation proved the result of the docking analysis. The effect of AMPs on ACE2, GRP78, TMPRSS2 and AT1R receptors can be a novel treatment for Covid-19.Communicated by Ramaswamy H. Sarma.

The Ability of Combined Flavonol and Trihydroxyorganic Acid to Suppress SARS-CoV-2 Reproduction

The global burden of COVID-19 continues to rise, and despite significant progress in vaccine development, there remains a critical need for effective treatments for the severe inflammation and acute lung injury associated with SARS-CoV-2 infection. In this study, we explored the antiviral properties of a plant-derived complex consisting of flavonol and hydroxyorganic acid compounds. Our research focused on the ability of the flavonol and hydroxyorganic acid complex to suppress the activity of several key proteins involved in the replication and maturation of SARS-CoV-2. These proteins include ACE2 protein, HRV 3C Protease, and Mpro (Main Protease). It was shown that the plant-based complex effectively inhibited the activity of these viral proteins. In addition to its effects on viral proteins, the flavonol and hydroxyorganic acid complex were shown to suppress viral replication in Vero E6 cells. At a dose of 22 μg/mL, the drug demonstrated maximum antiviral activity, significantly reducing the replication of SARS-CoV-2 in vitro. In preliminary studies, the complex showed both prophylactic and therapeutic potential, suggesting that it may be useful for preventing infection, as well as reducing the severity of disease once an individual has been infected with SARS-CoV-2. Based on the compelling results of this study, we propose the flavonol and hydroxyorganic acid complex as a potential therapeutic compound for SARS-CoV-2. Its ability to inhibit key viral proteins, suppress viral replication and exhibit protective and therapeutic effects positions it as a valuable candidate for further research and clinical evaluation. As the global fight against SARS-CoV-2 continues, plant-based therapies like this complex could complement existing treatments and provide new options for managing and treating the disease.

Quantitative analysis of two COVID-19 antiviral agents, favipiravir and remdesivir, in spiked human plasma using spectrophotometric methods; greenness evaluation

Favipiravir and remdesivir have been included in the COVID-19 treatment guidelines panel of several countries. The main objective of the current work is to develop the first validated green spectrophotometric methods for the determination of favipiravir and remdesivir in spiked human plasma. The UV absorption spectra of favipiravir and remdesivir have shown some overlap, making simultaneous determination difficult. Due to the considerable overlap, two ratio spectra manipulating spectrophotometric methods, namely, ratio difference and the first derivative of ratio spectra, enabled the determination of favipiravir and remdesivir in their pure forms and spiked plasma. The ratio spectra of favipiravir and remdesivir were derived by dividing the spectra of each drug by the suitable spectrum of another drug as a divisor to get the ratio spectra. Favipiravir was determined by calculating the difference between 222 and 256 nm of the derived ratio spectra, while calculating the difference between 247 and 271 nm of the derived ratio spectra enabled the determination of remdesivir. Moreover, the ratio spectra of every drug were transformed to the first order derivative using ∆λ = 4 and a scaling factor of 100. The first-order derivative amplitude values at 228 and 251.20 nm enabled the determination of favipiravir and remdesivir, respectively. Regarding the pharmacokinetic profile of favipiravir (C_max 4.43 µg/mL) and remdesivir (C_max 3027 ng/mL), the proposed methods have been successfully applied to the spectrophotometric determination of favipiravir and remdesivir in plasma matrix. Additionally, the greenness of the described methods was evaluated using three metrics systems: the national environmental method index, the analytical eco-scale, and the analytical greenness metric. The results demonstrated that the described models were in accordance with the environmental characteristics.

Th-1, Th-2, Th-9, Th-17, Th-22 type cytokine concentrations of critical COVID-19 patients after treatment with Remdesivir

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) rapidly spread around the world causing a pandemic known as coronavirus disease 2019 (COVID-19). Cytokine storm was directly correlated with severity of COVID-19 syndromes. We evaluated the levels of 13 cytokines in ICU hospitalized COVID-19 patients (n=29) before, and after treatment with Remdesivir as well as in healthy controls (n=29). Blood samples were obtained from ICU patients during ICU admission (before treatment) and 5 days after treatment with Remdesivir. A group of 29 age- and gender-matched healthy controls was also studied. Cytokine levels were evaluated by multiplex immunoassay method using a fluorescence labeled cytokine panel. In comparison to cytokine levels measured at ICU admission, serum levels were reduced of IL-6 (134.75 pg/mL vs. 20.73 pg/mL, P< 0.0001), TNF-α (121.67 pg/mL vs. 10.15 pg/mL, P< 0.0001) and IFN-γ (29.69 pg/mL vs. 22.27 pg/mL, P= 0.005), whereas serum level was increased of IL-4 (8.47 pg/mL vs. 12.44 pg/mL, P= 0.002) within 5 days after Remdesivir treatment. Comparing with before treatment, Remdesivir significantly reduced the levels of inflammatory (258.98 pg/mL vs. 37.43 pg/mL, P< 0.0001), Th1-type (31.24 pg/mL vs. 24.46 pg/mL, P= 0.007), and Th17-type (36.79 pg/mL vs. 26.22 pg/mL, P< 0.0001) cytokines in critical COVID-19 patients. However, after Remdesivir treatment, the concentrations of Th2-type cytokines were significantly higher than before treatment (52.69 pg/mL vs. 37.09 pg/mL, P< 0.0001). In conclusion, Remdesivir led to decrease levels of Th1-type and Th17-type cytokines and increase Th2-type cytokines in critical COVID-19 patients 5 days after treatment.

Is it possible to reduce the rate of vertical transmission and improve perinatal outcomes by inclusion of remdesivir in treatment regimen of pregnant women with COVID-19?

BACKGROUND

Coronavirus disease 2019 (COVID-19) is currently one of the world's most critical health issues so far. Given the importance of appropriate treatment in pregnancy and the controversies about Remdesivir effectiveness and complications, the present study aimed to evaluate the impact of Remdesivir on maternal, fetal, and perinatal outcomes in pregnant women with COVID-19 diseases.

METHODS

A total of 189 pregnant women with positive polymerase chain reaction (PCR) results for SARS-COV-2, and oxygen saturation [SpO2] of < 95%) were admitted to 12 hospitals affiliated with the Iran University of Medical Sciences from March 1st, 2020 to June 7th, 2021, namely the first four COVID-19 Picks in Iran. They were enrolled in this retrospective cohort study by census method and categorized into case and control groups, based on the inclusion of Remdesivir in their treatment protocol. Demographics, clinical outcomes, and pregnancy-related complications of the mothers and the neonates were compared between the two study groups.

RESULTS

A comparison of 54 mothers in the case and 135 in the control group showed no demographic and clinical characteristics difference. Neonates whose mothers did not receive Remdesivir had a higher rate of positive PCR (10.2%), compared to the Remdesivir group (1.9%) with a relative risk of 0.91 reported for Remdesivir (95% CI: 0.85-0.98, P = 0.04); besides, Remdesivir resulted in fewer neonatal intensive care unit admission rates in mild/moderate COVID-19 group (RR = 0.32, 95% CI: 0.105-1.02, P = 0.03). Although neonatal death between the two groups was not statistically significant, from the clinical point seems important; 1(1.9%) in the case vs. 9(7.2%) in the control group. Interestingly LOS (Length of Stay) in the hospital was longer in the case group (median of 7 vs. 3 days; P < 0.0001).

CONCLUSION

The inclusion of Remdesivir in the treatment protocol of pregnant women with COVID-19 may reduce vertical transmission and improve perinatal outcomes, thus being suggested to be considered.

A COVID Dilemma: How to Manage Pregnancies in Case of Severe Respiratory Failure?

To date, the impact of the COVID-19 pandemic on the world's health, economics and politics is still heavy, and efforts to mitigate virus transmission have caused remarkable disruption. From the early onset of the pandemic, generated by SARS-CoV-2 spread, the scientific community was aware of its impact on vulnerable individuals, including pregnant women. The purpose of this paper is to highlight scientific pitfalls and ethical dilemmas emerging from management of severe respiratory distress in pregnant women in order to add evidence to this topic through an ethical debate. In the here-presented paper, three cases of severe respiratory syndrome are analyzed. No specific therapeutic protocol was available to guide physicians in a cost-benefit balance, and unequivocal conduct was not a priori suggested from scientific evidence. However, vaccines' advent, viral variants lurking on the horizon and other possible pandemic challenges make it necessary to maximize the experience gained through these difficult years. Antenatal management of pregnancies complicated by COVID-19 infection with severe respiratory failure is still heterogeneous and ethical concerns must be pointed out.

Therapeutic Efficacy and Outcomes of Remdesivir versus Remdesivir with Tocilizumab in Severe SARS-CoV-2 Infection

The infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) generated many challenges to find an effective drug combination for hospitalized patients with severe forms of coronavirus disease 2019 (COVID-19) pneumonia. We conducted a retrospective cohort study, including 182 patients with severe COVID-19 pneumonia hospitalized between March and October 2021 in a Pneumology Hospital from Cluj-Napoca, Romania. Among patients treated with standard of care, 100 patients received remdesivir (R group) and 82 patients received the combination of remdesivir plus tocilizumab (RT group). We compared the clinical outcomes, the inflammatory markers, superinfections, oxygen requirement, intensive care unit (ICU) admission and mortality rate before drug administration and 7 days after in R group and RT group. Borg score and oxygen support showed an improvement in the R group (p < 0.005). Neutrophiles, C-reactive protein (CRP) and serum ferritin levels decreased significantly in RT group but with a higher rate of superinfection in this group. ICU admission and death did not differ significantly between groups. The combination of remdesivir plus tocilizumab led to a significantly improvement in the inflammatory markers and a decrease in the oxygen requirement. Although the superinfection rate was higher in RT group than in R group, no significant difference was found in the ICU admission and mortality rate between the groups.

Spectrofluorimetric quantitative analysis of favipiravir, remdesivir and hydroxychloroquine in spiked human plasma

Favipiravir, remdesivir and hydroxychloroquine have been suggested in COVID-19 Treatment Guidelines Panel of many countries. Synchronous spectrofluorometric measurement provides sensitive tool for resolving the overlapped spectra of multicomponent drugs through converting the wider spectra to narrower sharp spectra. This work introduces the first fluorescence spectroscopic method for quantitative analysis of favipiravir, remdesivir and hydroxychloroquine in spiked human plasma. Testing the fluorescence spectra of favipiravir, remdesivir and hydroxychloroquine shows severe overlap, which hinders the direct quantification of the cited drugs. To overcome the overlapping issue, the drugs under the study have been measured in the synchronous mode at Δλ = 60 nm. Favipiravir could be measured directly at 423 nm without interference of remdesivir or hydroxychloroquine. Synchronous measuring the cited drugs at Δλ = 130 nm with mathematical transforming to the first order derivative spectra allowing remdesivir and hydroxychloroquine at 384 nm and 394 nm, respectively without interference from favipiravir. Different factors affecting the spectrofluorometric measurement process have been verified. The drugs under the study have been successfully quantitatively analyzed in the spiked plasma using the proposed method.

Two Ligand-Binding Sites on SARS-CoV-2 Non-Structural Protein 1 Revealed by Fragment-Based X-ray Screening

The regular reappearance of coronavirus (CoV) outbreaks over the past 20 years has caused significant health consequences and financial burdens worldwide. The most recent and still ongoing novel CoV pandemic, caused by Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) has brought a range of devastating consequences. Due to the exceptionally fast development of vaccines, the mortality rate of the virus has been curbed to a significant extent. However, the limitations of vaccination efficiency and applicability, coupled with the still high infection rate, emphasise the urgent need for discovering safe and effective antivirals against SARS-CoV-2 by suppressing its replication or attenuating its virulence. Non-structural protein 1 (nsp1), a unique viral and conserved leader protein, is a crucial virulence factor for causing host mRNA degradation, suppressing interferon (IFN) expression and host antiviral signalling pathways. In view of the essential role of nsp1 in the CoV life cycle, it is regarded as an exploitable target for antiviral drug discovery. Here, we report a variety of fragment hits against the N-terminal domain of SARS-CoV-2 nsp1 identified by fragment-based screening via X-ray crystallography. We also determined the structure of nsp1 at atomic resolution (0.99 Å). Binding affinities of hits against nsp1 and potential stabilisation were determined by orthogonal biophysical assays such as microscale thermophoresis and thermal shift assays. We identified two ligand-binding sites on nsp1, one deep and one shallow pocket, which are not conserved between the three medically relevant SARS, SARS-CoV-2 and MERS coronaviruses. Our study provides an excellent starting point for the development of more potent nsp1-targeting inhibitors and functional studies on SARS-CoV-2 nsp1.

Broad-Spectrum Small-Molecule Inhibitors of the SARS-CoV-2 Spike-ACE2 Protein-Protein Interaction from a Chemical Space of Privileged Protein Binders

Therapeutically useful small-molecule inhibitors (SMIs) of protein−protein interactions (PPIs) initiating the cell attachment and entry of viruses could provide novel alternative antivirals that act via mechanisms similar to that of neutralizing antibodies but retain the advantages of small-molecule drugs such as oral bioavailability and low likelihood of immunogenicity. From screening our library, which is focused around the chemical space of organic dyes to provide good protein binders, we have identified several promising SMIs of the SARS-CoV-2 spike—ACE2 interaction, which is needed for the attachment and cell entry of this coronavirus behind the COVID-19 pandemic. They included organic dyes, such as Congo red, direct violet 1, and Evans blue, which seem to be promiscuous PPI inhibitors, as well as novel drug-like compounds (e.g., DRI-C23041). Here, we show that in addition to the original SARS-CoV-2 strain, these SMIs also inhibit this PPI for variants of concern including delta (B.1.617.2) and omicron (B.1.1.529) as well as HCoV-NL63 with low- or even sub-micromolar activity. They also concentration-dependently inhibited SARS-CoV-2-S expressing pseudovirus entry into hACE2-expressing cells with low micromolar activity (IC50 < 10 μM) both for the original strain and the delta variant. DRI-C23041 showed good therapeutic (selectivity) index, i.e., separation between activity and cytotoxicity (TI > 100). Specificities and activities require further optimization; nevertheless, these results provide a promising starting point toward novel broad-spectrum small-molecule antivirals that act via blocking the interaction between the spike proteins of coronaviruses and their ACE2 receptor initiating cellular entry.

Synthesis of novel C-nucleoside analogues bearing an anomeric cyano and a 1,2,3-triazole nucleobase as potential antiviral agents

A linear sequence to access a novel series of C-nucleosides bearing a quaternary carbon at the anomeric position tethered to a 4-substituted 1,2,3-triazole ring is described. Most of the compounds were obtained from a C-1 alkynyl furanoside, by a tandem or two-step CuAAC/functionalisation sequence, along with a diastereoselective cyanation of the furanoside derivatives in acidic conditions.

Identification of novel SARS-CoV-2 RNA dependent RNA polymerase (RdRp) inhibitors: From in silico screening to experimentally validated inhibitory activity

The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in 2019 has posed a serious threat to global health and the economy for over two years, prompting the need for development of antiviral inhibitors. Due to its vital role in viral replication, RNA-dependent RNA polymerase (RdRp) is a promising therapeutic target. Herein, we analyzed amino acid sequence conservation of RdRp across coronaviruses. The conserved amino acids at the catalytic binding site served as the ligand-contacting residues for in silico screening to elucidate possible resistant mutation. Molecular docking was employed to screen inhibitors of SARS-CoV-2 from the ZINC ChemDiv database. The top-ranked compounds selected from GOLD docking were further investigated for binding modes at the conserved residues of RdRp, and ten compounds were selected for experimental validation. Of which, three compounds exhibited promising antiviral activity. The most promising candidate showed a half-maximal effective concentration (EC50) of 5.04 µM. Molecular dynamics simulations, binding free-energy calculation and hydrogen bond analysis were performed to elucidate the critical interactions providing a foundation for developing lead compounds effective against SARS-CoV-2.

Efficacy and Safety of Remdesivir over Two Waves of the SARS-CoV-2 Pandemic

The aim of this study is to describe the features, the outcomes, and the clinical issues related to Remdesivir administration of a cohort of 220 patients (pts) with COVID-19 hospitalized throughout the last two pandemic waves in Italy. One hundred and nine pts were enrolled from 1 September 2020, to 28 February 2021 (Group A) and 111 from 1 March to 30 September 2021 (Group B). Notably, no differences were reported between the two groups neither in the timing of hospitalization. nor in the timing of Remdesivir administration from symptoms onset. Remarkably, a higher proportion of pts with severe COVID-19 was observed in Group B (25% vs. 10%, p < 0.001). At univariate and multivariate analysis, rather than the timing of Remdesivir administration, age, presence of coexisting conditions, D-dimers, and O2 flow at admission correlated positively to progression to non-invasive ventilation, especially for patients in Group B. However, the rate of admission in the Intensive Care Unit and/or death was comparable in the two groups (7% vs. 4%). Negligible variations in serum GOT, GPT, GGT, and eGFR levels were detected. A mean reduction in heart rate was noticed within the first three days of antiviral treatment (p < 0.001). Low rate of ICU admission, high rate of clinical recovery, and good drug safety were observed in COVID-19 patients treated with Remdesivir during two diverse pandemic waves.

Effectiveness of Remdesivir, Lopinavir/Ritonavir, and Favipiravir for COVID-19 Treatment: A Systematic Review

BACKGROUND

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a novel strain that causes acute respiratory illnesses known as coronavirus disease 2019 (COVID-19). Currently, there is limited information regarding the therapeutic management for this disease. Several studies have stated that antivirals drugs such as remdesivir, favipiravir, and lopinavir/ritonavir may potentially inhibit the virus from spreading to the host.

OBJECTIVE

The aim of this systematic review was to summarize the clinical effectiveness and safety of remdesivir, favipiravir, and lopinavir/ritonavir on COVID-19.

METHODS

The PubMed and Cochrane Library databases were searched up to July 2021 to identify eligible experimental randomized controlled trials on remdesivir, favipiravir, and lopinavir/ritonavir for COVID-19 patients. This systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline.

RESULTS

From 158 references, 15 studies were included in the review. The results showed that remdesivir has some potential benefits for hospitalized COVID-19 patients, as seen from clinical improvements such as faster recovery time, less duration of hospitalization, and fewer respiratory side effects among COVID-19 patients. However, the impact of remdesivir in reducing mortality remains uncertain. Treatment with favipiravir has shown promising improvement in the clinical status of COVID-19 patients, although the results suggested no significant differences in some clinical parameters such as length of hospitalizations and clinical recovery. A combination of favipiravir with other supportive therapy showed more favorable outcomes for COVID-19 patients. Furthermore, the use of lopinavir/ritonavir in COVID-19 patients reported no significant clinical improvement compared to standard care with notable adverse effect reactions.

CONCLUSION

This study provides an overview of the evidence-based role of remdesivir, favipiravir, and lopinavir/ritonavir in the management of COVID-19. A thorough assessment of the benefit-risk profile in COVID-19 patients is urgently needed. The current review was based on very limited available data; therefore, further well-designed clinical trials are required.