Favipiravir in patients hospitalised with COVID-19 (PIONEER trial): a multicentre, open-label, phase 3, randomised controlled trial of early intervention versus standard care.

BACKGROUND: COVID-19 has overwhelmed health services globally. Oral antiviral therapies are licensed worldwide, but indications and efficacy rates vary. We aimed to evaluate the safety and efficacy of oral favipiravir in patients hospitalised with COVID-19. METHODS: We conducted a multicentre, open-label, randomised controlled trial of oral favipiravir in adult patients who were newly admitted to hospital with proven or suspected COVID-19 across five sites in the UK (n=2), Brazil (n=2) and Mexico (n=1). Using a permuted block design, eligible and consenting participants were randomly assigned (1:1) to receive oral favipiravir (1800 mg twice daily for 1 day; 800 mg twice daily for 9 days) plus standard care, or standard care alone. All caregivers and patients were aware of allocation and those analysing data were aware of the treatment groups. The prespecified primary outcome was the time from randomisation to recovery, censored at 28 days, which was assessed using an intention-to-treat approach. Post-hoc analyses were used to assess the efficacy of favipiravir in patients aged younger than 60 years, and in patients aged 60 years and older. The trial was registered with clinicaltrials.gov, NCT04373733. FINDINGS: Between May 5, 2020 and May 26, 2021, we assessed 503 patients for eligibility, of whom 499 were randomly assigned to favipiravir and standard care (n=251) or standard care alone (n=248). There was no significant difference between those who received favipiravir and standard care, relative to those who received standard care alone in time to recovery in the overall study population (hazard ratio [HR] 1·06 [95% CI 0·89-1·27]; n=499; p=0·52). Post-hoc analyses showed a faster rate of recovery in patients younger than 60 years who received favipiravir and standard care versus those who had standard care alone (HR 1·35 [1·06-1·72]; n=247; p=0·01). 36 serious adverse events were observed in 27 (11%) of 251 patients administered favipiravir and standard care, and 33 events were observed in 27 (11%) of 248 patients receiving standard care alone, with infectious, respiratory, and cardiovascular events being the most numerous. There was no significant between-group difference in serious adverse events per patient (p=0·87). INTERPRETATION: Favipiravir does not improve clinical outcomes in all patients admitted to hospital with COVID-19, however, patients younger than 60 years might have a beneficial clinical response. The indiscriminate use of favipiravir globally should be cautioned, and further high-quality studies of antiviral agents, and their potential treatment combinations, are warranted in COVID-19. FUNDING: LifeArc and CW+.

One-step synthesis of favipiravir from Selectfluor® and 3-hydroxy-2-pyrazinecarboxamide in an ionic liquid.

Favipiravir is an important selective antiviral that emerged as an alternative against COVID-19 during the pandemic. Its synthesis has gained great interest and the conventional strategies proceed through multiple-step protocols (6-7 reaction steps), which involve, in addition, several drawbacks with global yields, lower than 34%. Herein, a simple, economical, eco-friendly and scalable (1 g) one-step protocol for the synthesis of favipiravir from the direct fluorination of the available 3-hydroxy-2-pyrazinecarboxamide with Selectfluor® is reported. The reaction proceeds easily in BF4-BMIM through a simple operational work-up, affording the favipiravir with a yield of 50% without the need of a special catalyst/additive. The key point of the present strategy was the use of the ionic liquid of BF4-BMIM, which helps to minimize the several chemical limitations derived from 3-hydroxy-2-pyrazinecarboxamide as a substrate for the direct Selectfluor-mediated fluorination. All these chemical reactivity aspects are also discussed in detail.

Favipiravir Use in Kidney Transplant Recipients with COVID-19: A Single-Center Experience.

OBJECTIVES: Kidney transplant recipients are among the high-risk groups for severe COVID-19. To date, no specific antiviral agent has proved uniformly effective against SARS-CoV-2. Favipiravir, the recommended drug by the Turkish Ministry of Health, was uniformly supplied to all patients diagnosed with COVID-19 by a positive nasopharyngeal swab polymerase chain reaction test. The aim of our study was to retrospectively compare our kidney transplant recipients treated with favipiravir who developed COVID-19 infection versus those not treated with favipiravir during the clinical course of the disease, with a special emphasis on the occurrence of side effects and adverse events. MATERIALS AND METHODS: We included 37 consecutive kidney transplant recipients with a median age of 46 years (62.2% women). Recipients included 8 with deceased donors and 29 with living related donors; median posttransplant survival was 8.0 years (IQR, 5.5-12.5 years). RESULTS: Twenty-six patients (70.3%) received favipiravir, and 11 (29.7%) did not. There were no statistically significant differences between the groups for baseline demographic characteristics and clinical and laboratory data, except that the favipiravir-treated patients were older and had a higher requirement of oxygen treatment. There were no statistically significant differences between the 2 groups for the course and outcome of COVID-19 infection with regard to adverse side effects/events associated with favipiravir. Laboratory data at baseline, day 7, and day 30 were also comparable between the groups. CONCLUSIONS: Although the efficacy of favipiravir for treatment of COVID-19 infection remains controversial, favipiravir is safe for kidney transplant recipients.

Electrochemical Sensing of Favipiravir with an Innovative Water-Dispersible Molecularly Imprinted Polymer Based on the Bimetallic Metal-Organic Framework: Comparison of Morphological Effects.

Molecularly imprinted polymers (MIPs) are widely used as modifiers in electrochemical sensors due to their high sensitivity and promise of inexpensive mass manufacturing. Here, we propose and demonstrate a novel MIP-sensor that can measure the electrochemical activity of favipiravir (FAV) as an antiviral drug, thereby enabling quantification of the concentration of FAV in biological and river water samples and in real-time. MOF nanoparticles' application with various shapes to determine FAV at nanomolar concentrations was described. Two different MOF nanoparticle shapes (dodecahedron and sheets) were systematically compared to evaluate the electrochemical performance of FAV. After carefully examining two different morphologies of MIP-Co-Ni@MOF, the nanosheet form showed a higher performance and efficiency than the nanododecahedron. When MIP-Co/Ni@MOF-based and NIP-Co/Ni@MOF electrodes (nanosheets) were used instead, the minimum target concentrations detected were 7.5 × 10-11 (MIP-Co-Ni@MOF) and 8.17 × 10-9 M (NIP-Co-Ni@MOF), respectively. This is a significant improvement (>102), which is assigned to the large active surface area and high fraction of surface atoms, increasing the amount of greater analyte adsorption during binding. Therefore, water-dispersible MIP-Co-Ni@MOF nanosheets were successfully applied for trace-level determination of FAV in biological and water samples. Our findings seem to provide useful guidance in the molecularly imprinted polymer design of MOF-based materials to help establish quantitative rules in designing MOF-based sensors for point of care (POC) systems.

HPLC-DAD quantification of favipiravir in whole blood after extraction from volumetric absorptive microsampling devices.

Favipiravir is a prodrug of T-1105 made by modifying the pyrazine group as a COVID-19 therapy. During the pandemic, a safe and comfortable biosampling technique is needed for the subject or patient. Volumetric Absorptive Microsampling (VAMS) is a biosampling technique with a small blood volume and minimum hematocrit effect. The aims of this study were to develop and validate an analytical method for quantifying favipiravir extracted from VAMS using High Performance Liquid Chromatography - Photodiode Array with remdesivir as an internal standard. Analysis of favipiravir was performed using a C18 column (Waters, Sunfire™ 5 µm; 250 × 4.6 mm), with injection volume of 50 µL, flow rate of 0.8 mL/min, column temperature 30 ℃, and wavelength 300 nm. The separation was conducted under gradient elution with mobile phase consists of acetonitrile-0.2 % formic acid-20 mM sodium dihydrogen phosphate pH 3.5 and run time 12 min. Sample preparation was carried out using a protein precipitation method with 500 µL of methanol as precipitating agent. Samples were mixed on vortex for 30 s, sonicated for 15 min, and centrifuged at 10,000 rpm for 10 min. Lower Limit of Quantification (LLOQ) obtained was 0.5 µg/mL and the calibration curve ranged from 0.5 to 160 µg/mL. Sensitivity, linearity, selectivity, carry-over, accuracy, precision, recovery, and stability were validated by the guideline from Food and Drug Administration 2018. The method developed has successfully met the full validation requirements by FDA 2018 with the LLOQ obtained was 0.5 µg /mL.

A systematic review and Bayesian network meta-analysis for comparative safety assessment of favipiravir interventions in hospitalized COVID-19 patients.

INTRODUCTION: COVID-19 is a coronavirus-based infectious illness that was first detected at the end of 2019 in Wuhan, China. The novel virus induces severe acute respiratory syndrome (SARS-CoV-2) and has spread globally, resulting in an ongoing pandemic. There is still a lack of evidence for direct comparison of favipiravir therapy. Network meta-analysis (NMA), may incorporate direct and indirect comparisons in a pooled computation while depending on strong assumptions and premises. This study provides evidence-based recommendations on the safety of currently used clinical pharmacological treatments compared to favipiravir for COVID-19 patients. METHODOLOGY: We conducted a systematic review and Bayesian NMA. We searched the primary databases and clinical trials center for reports of short-term, randomized controlled trials (RCTs) of favipiravir for COVID-19 treatment. The primary endpoints here considered were any adverse events observed or reported during the treatment cycle with estimates of odds ratio (OR) and 95% confidence interval (CI), until November 6, 2021. RESULTS: Between January 2020 and July 2021, 908 individuals were randomly assigned to one of the seven active prescription medication regimens or placebo in this study, generating seven direct comparisons on 12 data points. The safety of favipiravir over the four clinically efficacious monotherapies or combinations including tocilizumab, arbidol, lopinavir + ritonavir, and chloroquine remained unknown due to the lack of a significant difference and the limited sample size. CONCLUSIONS: Overall, comparative rankings could assist doctors and guideline developers in decision-making. We have also concluded that the safety of favipiravir requires further attention.

Herpesviral encephalitis associated with bortezomib use in a patient with multiple myeloma and associated light-chain amyloidosis.

INTRODUCTION: Bortezomib is proteasome inhibitor used in multiple myeloma treatment. The reactivation of herpes simplex virus (HSV) and varicella-zoster virus (VZV) during bortezomib-based therapy is a well-known adverse event. Antiviral prophylaxis is mandatory. Nevertheless, reports of herpesviral encephalitis are scarce. CASE REPORT: A 57-year-old multiple myeloma patient who during CyBorD protocol (Bortezomib, cyclophosphamide, and dexamethasone), after a transient suspension of antiviral prophylaxis presented progressive headaches unresponsive to conventional analgesics, asthenia, fever, episodic visual hallucinations, and vesicular lesions in the right supraorbital and frontal region. Herpetic encephalitis was diagnosed after detecting herpes zoster in cerebrospinal fluid. MANAGEMENT & OUTCOME: The patient was treated with acyclovir 500mg every 6 hours for 21 days, and subsequent valacyclovir prophylaxis achieving an excellent clinical evolution. Anti-myeloma treatment was changed to lenalidomide and dexamethasone achieving a durable complete response. Herpesviral encephalitis is a rare but severe complication associated with the use of Bortezomib, especially when patients did not receive acyclovir prophylaxis. However, a rapid detection based on the clinical suspicion, and the prompt start of treatment, may lead to overcome this adverse event.

Virtual Screening and Quantum Chemistry Analysis for SARS-CoV-2 RNA-Dependent RNA Polymerase Using the ChEMBL Database: Reproduction of the Remdesivir-RTP and Favipiravir-RTP Binding Modes Obtained from Cryo-EM Experiments with High Binding Affinity.

The novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was identified as the pathogenic cause of coronavirus disease 2019 (COVID-19). The RNA-dependent RNA polymerase (RdRp) of SARS-CoV-2 is a potential target for the treatment of COVID-19. An RdRp complex:dsRNA structure suitable for docking simulations was prepared using a cryo-electron microscopy (cryo-EM) structure (PDB ID: 7AAP; resolution, 2.60 Å) that was reported recently. Structural refinement was performed using energy calculations. Structure-based virtual screening was performed using the ChEMBL database. Through 1,838,257 screenings, 249 drugs (37 approved, 93 clinical, and 119 preclinical drugs) were predicted to exhibit a high binding affinity for the RdRp complex:dsRNA. Nine nucleoside triphosphate analogs with anti-viral activity were included among these hit drugs, and among them, remdesivir-ribonucleoside triphosphate and favipiravir-ribonucleoside triphosphate adopted a similar docking mode as that observed in the cryo-EM structure. Additional docking simulations for the predicted compounds with high binding affinity for the RdRp complex:dsRNA suggested that 184 bioactive compounds could be anti-SARS-CoV-2 drug candidates. The hit bioactive compounds mainly consisted of a typical noncovalent major groove binder for dsRNA. Three-layer ONIOM (MP2/6-31G:AM1:AMBER) geometry optimization calculations and frequency analyses (MP2/6-31G:AMBER) were performed to estimate the binding free energy of a representative bioactive compound obtained from the docking simulation, and the fragment molecular orbital calculation at the MP2/6-31G level of theory was subsequently performed for analyzing the detailed interactions. The procedure used in this study represents a possible strategy for discovering anti-SARS-CoV-2 drugs from drug libraries that could significantly shorten the clinical development period for drug repositioning.

Identification of Drug Combination Therapies for SARS-CoV-2: A Molecular Dynamics Simulations Approach.

Purpose: The development of effective treatments for coronavirus infectious disease 19 (COVID-19) caused by SARS-Coronavirus-2 was hindered by the little data available about this virus at the start of the pandemic. Drug repurposing provides a good strategy to explore approved drugs' possible SARS-CoV-2 antiviral activity. Moreover, drug synergism is essential in antiviral treatment due to improved efficacy and reduced toxicity. In this work, we studied the effect of approved and investigational drugs on one of SARS-CoV-2 essential proteins, the main protease (Mpro), in search of antiviral treatments and/or drug combinations. Methods: Different possible druggable sites of Mpro were identified and screened against an in-house library of more than 4000 chemical compounds. Molecular dynamics simulations were carried out to explore conformational changes induced by different ligands' binding. Subsequently, the inhibitory effect of the identified compounds and the suggested drug combinations on the Mpro were established using a 3CL protease (SARS-CoV-2) assay kit. Results: Three potential inhibitors in three different binding sites were identified; favipiravir, cefixime, and carvedilol. Molecular dynamics simulations predicted the synergistic effect of two drug combinations: favipiravir/cefixime, and favipiravir/carvedilol. The in vitro inhibitory effect of the predicted drug combinations was established on this enzyme. Conclusion: In this work, we could study one of the promising SARS-CoV-2 viral protein targets in searching for treatments for COVID-19. The inhibitory effect of several drugs on Mpro was established in silico and in vitro assays. Molecular dynamics simulations showed promising results in predicting the synergistic effect of drug combinations.

Efficacy of Early Treatment With Favipiravir on Disease Progression Among High-Risk Patients With Coronavirus Disease 2019 (COVID-19): A Randomized, Open-Label Clinical Trial.

BACKGROUND: The role of favipiravir in preventing disease progression in coronavirus disease 2019 (COVID-19) remains uncertain. We aimed to determine its effect in preventing disease progression from nonhypoxia to hypoxia among high-risk COVID-19 patients. METHODS: This was an open-label, randomized clinical trial conducted at 14 public hospitals across Malaysia (February-July 2021) among 500 symptomatic, RT-PCR-confirmed COVID-19 patients, aged ≥50 years with ≥1 comorbidity, and hospitalized within first 7 days of illness. Patients were randomized 1:1 to favipiravir plus standard care or standard care alone. Favipiravir was administered at 1800 mg 2×/day on day 1 followed by 800 mg 2×/day until day 5. The primary endpoint was rate of clinical progression from nonhypoxia to hypoxia. Secondary outcomes included rates of mechanical ventilation, intensive care unit (ICU) admission, and in-hospital mortality. RESULTS: Of 500 patients randomized (mean [SD] age, 62.5 [8.0] years; 258 women [51.6%]; 251 [50.2%] had COVID-19 pneumonia), 487 (97.4%) patients completed the trial. Clinical progression to hypoxia occurred in 46 (18.4%) patients on favipiravir plus standard care and 37 (14.8%) on standard care alone (OR, 1.30; 95% CI: .81-2.09; P = .28). All 3 prespecified secondary endpoints were similar between both groups. Mechanical ventilation occurred in 6 (2.4%) vs 5 (2.0%) (OR, 1.20; 95% CI: .36-4.23; P = .76), ICU admission in 13 (5.2%) vs 12 (4.8%) (OR, 1.09; 95% CI: .48-2.47; P = .84), and in-hospital mortality in 5 (2.0%) vs 0 (OR, 12.54; 95% CI: .76-207.84; P = .08) patients. CONCLUSIONS: Among COVID-19 patients at high risk of disease progression, early treatment with oral favipiravir did not prevent their disease progression from nonhypoxia to hypoxia. CLINICAL TRIALS REGISTRATION: ClinicalTrials.gov (NCT04818320).

Antiviral efficacy of favipiravir against Zika and SARS-CoV-2 viruses in non-human primates.

The COVID-19 pandemic has exemplified that rigorous evaluation in large animal models is key for translation from promising in vitro results to successful clinical implementation. Among the drugs that have been largely tested in clinical trials but failed so far to bring clear evidence of clinical efficacy is favipiravir, a nucleoside analogue with large spectrum activity against several RNA viruses in vitro and in small animal models. Here, we evaluate the antiviral activity of favipiravir against Zika or SARS-CoV-2 virus in cynomolgus macaques. In both models, high doses of favipiravir are initiated before infection and viral kinetics are evaluated during 7 to 15 days after infection. Favipiravir leads to a statistically significant reduction in plasma Zika viral load compared to untreated animals. However, favipiravir has no effects on SARS-CoV-2 viral kinetics, and 4 treated animals have to be euthanized due to rapid clinical deterioration, suggesting a potential role of favipiravir in disease worsening in SARS-CoV-2 infected animals. To summarize, favipiravir has an antiviral activity against Zika virus but not against SARS-CoV-2 infection in the cynomolgus macaque model. Our results support the clinical evaluation of favipiravir against Zika virus but they advocate against its use against SARS-CoV-2 infection.

State-of-the-Art Molecular Dynamics Simulation Studies of RNA-Dependent RNA Polymerase of SARS-CoV-2.

Molecular dynamics (MD) simulations are powerful theoretical methods that can reveal biomolecular properties, such as structure, fluctuations, and ligand binding, at the level of atomic detail. In this review article, recent MD simulation studies on these biomolecular properties of the RNA-dependent RNA polymerase (RdRp), which is a multidomain protein, of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are presented. Although the tertiary structures of RdRps in SARS-CoV-2 and SARS-CoV are almost identical, the RNA synthesis activity of RdRp of SARS-CoV is higher than SARS-CoV-2. Recent MD simulations observed a difference in the dynamic properties of the two RdRps, which may cause activity differences. RdRp is also a drug target for Coronavirus disease 2019 (COVID-19). Nucleotide analogs, such as remdesivir and favipiravir, are considered to be taken up by RdRp and inhibit RNA replication. Recent MD simulations revealed the recognition mechanism of RdRp for these drug molecules and adenosine triphosphate (ATP). The ligand-recognition ability of RdRp decreases in the order of remdesivir, favipiravir, and ATP. As a typical recognition process, it was found that several lysine residues of RdRp transfer these ligand molecules to the binding site such as a "bucket brigade." This finding will contribute to understanding the mechanism of the efficient ligand recognition by RdRp. In addition, various simulation studies on the complexes of SARS-CoV-2 RdRp with several nucleotide analogs are reviewed, and the molecular mechanisms by which these compounds inhibit the function of RdRp are discussed. The simulation studies presented in this review will provide useful insights into how nucleotide analogs are recognized by RdRp and inhibit the RNA replication.

Pulmonary delivery of favipiravir inhalation solution for COVID-19 treatment: in vitro characterization, stability, in vitro cytotoxicity, and antiviral activity using real time cell analysis.

Favipiravir, an RNA-dependent RNA polymerase (RdRp) inhibitor, is used to treat patients infected with influenza virus and most recently with SARS-CoV-2. However, poor accumulation of favipiravir in lung tissue following oral administration has required an alternative method of administration that directly targets the lungs. In this study, an inhalation solution of favipiravir at a concentration of 2 mg mL-1 was developed and characterized for the first time. The chemical stability of inhaled favipiravir solution in two different media, phosphate buffer saline (PBS) and normal saline (NS), was investigated under different conditions: 5 ± 3 °C, 25 ± 2 °C/60% RH ± 5% RH, and 40 ± 2 °C/75% RH ± 5% RH; in addition to constant light exposure. As a result, favipiravir solution in PBS revealed superior stability over 12 months at 5 ± 3 °C. Antiviral activity of favipiravir was assessed at the concentrations between 0.25 and 3 mg mL-1 with real time cell analyzer on Vero-E6 that were infected with SARS-CoV-2/B.1.36. The optimum concentration was found to be 2 mg mL-1, where minimum toxicity and sufficient antiviral activity was observed. Furthermore, cell viability assay against Calu-3 lung epithelial cells confirmed the biocompatibility of favipiravir at concentrations up to 50 µM (7.855 mg mL-1). The in vitro aerodynamic profiles of the developed inhaled favipiravir formulation, when delivered with soft-mist inhaler indicated good lung targeting properties. These results suggest that favipiravir solution prepared with PBS could be considered as a suitable and promising inhalation formulation for pulmonary delivery in the treatment of patients with COVID-19.

Is Favipiravir a Potential Therapeutic Agent in the Treatment of Intervertebral Disc Degeneration by Suppressing Autophagy and Apoptosis?

AIM: To evaluate the effects of favipiravir (FVP) on cell viability and cytotoxicity in human degenerated primary intervertebral disc (IVD) tissue cell cultures. Furthermore, the protein expressions of hypoxia-inducible factor 1 alpha (HIF-1α), nuclear factor-kappa-b (NF-kB), and interleukin-1 beta (IL-1ß) were also examined. MATERIAL AND METHODS: Untreated cell cultures served as the control group, named group 1. Cell cultures treated with FVP served as the study group, named group 2. Pharmacomolecular analyses were performed in all groups at 0, 24, 48, and 72 hours (h). Obtained data were evaluated statistically. RESULTS: Cell proliferation was suppressed in the FVP-treated samples compared to the control group samples at 24 and 72 h, and this was statistically significant (p < 0.05). Decreased or increased protein expression levels of HIF-1α, NF-κB, and IL-1ß in FVPtreated samples may be an indication of suppression in anabolic events as well as proliferation in IVD cultures. FVP administration showed that AF/NP cells in a culture medium may induce a strong inflammatory response to FVP. This strong inflammatory response is likely to cause slowed proliferation. It may also be a trigger for many catabolic events. NF-κB expression increased within the first 24 h and then decreased rapidly. Based on the data obtained, it may be suggested that the rapidly increasing NF-kB may have stimulated the expression of many antiproliferative genes. CONCLUSION: The suppression of IL-1ß and NF-kB protein expressions in IVD cells treated with FVP is important in the treatment of IVD degeneration (IDD). If the protein expression of HIF-1α could be increased along with the suppression of IL-1ß and NF-kB, FVP would perhaps be a promising pharmacological agent in the treatment of IDD.

Early treatment of Favipiravir in COVID-19 patients without pneumonia: a multicentre, open-labelled, randomized control study.

We investigated Favipiravir (FPV) efficacy in mild cases of COVID-19 without pneumonia and its effects towards viral clearance, clinical condition, and risk of COVID-19 pneumonia development. PCR-confirmed SARS-CoV-2-infected patients without pneumonia were enrolled (2:1) within 10 days of symptomatic onset into FPV and control arms. The former received 1800 mg FPV twice-daily (BID) on Day 1 and 800 mg BID 5-14 days thereafter until negative viral detection, while the latter received only supportive care. The primary endpoint was time to clinical improvement, defined by a National Early Warning Score (NEWS) of ≤1. 62 patients (41 female) comprised the FPV arm (median age: 32 years, median BMI: 22 kg/m²) and 31 patients (19 female) comprised the control arm (median age: 28 years, median BMI: 22 kg/m²). The median time to sustained clinical improvement, by NEWS, was 2 and 14 days for FPV and control arms, respectively (adjusted hazard ratio (aHR) of 2.77, 95% CI 1.57-4.88, P < .001). The FPV arm also had significantly higher likelihoods of clinical improvement within 14 days after enrolment by NEWS (79% vs. 32% respectively, P < .001). 8 (12.9%) and 7 (22.6%) patients in FPV and control arms developed mild pneumonia at a median (range) of 6.5 (1-13) and 7 (1-13) days after treatment, respectively (P = .316). All recovered well without complications. We can conclude that early treatment of FPV in symptomatic COVID-19 patients without pneumonia was associated with faster clinical improvement.Trial registration: Thai Clinical Trials Registry identifier: TCTR20200514001.

IDentif.AI-Omicron: Harnessing an AI-Derived and Disease-Agnostic Platform to Pinpoint Combinatorial Therapies for Clinically Actionable Anti-SARS-CoV-2 Intervention.

Nanomedicine-based and unmodified drug interventions to address COVID-19 have evolved over the course of the pandemic as more information is gleaned and virus variants continue to emerge. For example, some early therapies (e.g., antibodies) have experienced markedly decreased efficacy. Due to a growing concern of future drug resistant variants, current drug development strategies are seeking to find effective drug combinations. In this study, we used IDentif.AI, an artificial intelligence-derived platform, to investigate the drug-drug and drug-dose interaction space of six promising experimental or currently deployed therapies at various concentrations: EIDD-1931, YH-53, nirmatrelvir, AT-511, favipiravir, and auranofin. The drugs were tested in vitro against a live B.1.1.529 (Omicron) virus first in monotherapy and then in 50 strategic combinations designed to interrogate the interaction space of 729 possible combinations. Key findings and interactions were then further explored and validated in an additional experimental round using an expanded concentration range. Overall, we found that few of the tested drugs showed moderate efficacy as monotherapies in the actionable concentration range, but combinatorial drug testing revealed significant dose-dependent drug-drug interactions, specifically between EIDD-1931 and YH-53, as well as nirmatrelvir and YH-53. Checkerboard validation analysis confirmed these synergistic interactions and also identified an interaction between EIDD-1931 and favipiravir in an expanded range. Based on the platform nature of IDentif.AI, these findings may support further explorations of the dose-dependent drug interactions between different drug classes in further pre-clinical and clinical trials as possible combinatorial therapies consisting of unmodified and nanomedicine-enabled drugs, to combat current and future COVID-19 strains and other emerging pathogens.

Investigation of developmental toxicity of favipiravir on fetal bone and embryonic development.

BACKGROUND: Favipiravir is one of the essential antiviral drugs used for the treatment of coronavirus disease (COVID-19) in some countries. However, there is not enough information about used, especially in pregnancy. Therefore, in this study, it was aimed to determine the developmental toxicity of favipiravir on fetal bone development and embryonic development. METHODS: In this study, 16 pregnant wistar albino rats were used. The rats were divided into four groups: Control (saline) and Group A (50 mg/kg × 5 days), Group B (50 mg/kg × 1 days + 20 mg/kg × 4 days), Group C (20 mg/kg × 5 days). Solutions were administered to the rats by oral gavage from the 10th to 14th days of pregnancy, twice a day. The skeletal system development of fetuses was examined with double skeletal staining and immunohistochemical staining methods. RESULTS: A total of 72 fetuses from pregnant rats, 18 in each group, were included in the study. As a result, depending on favipiravir dose increase, in experimental groups, it was determined that the statistically significant decrease on the ossification rates of anterior and posterior extremity bones, and length and weight of fetuses. CONCLUSION: Exposure to favipiravir during pregnancy impairs bone metabolism and bone formation-resorption stages and may cause developmental delay.