Favipiravir, remdesivir, and lopinavir: metabolites, degradation products and their analytical methods

Severe acute respiratory syndrome 2 (SARS-CoV-2) caused the emergence of the COVID-19 pandemic all over the world. Several studies have suggested that antiviral drugs such as favipiravir (FAV), remdesivir (RDV), and lopinavir (LPV) may potentially prevent the spread of the virus in the host cells and person-to-person transmission. Simultaneously with the widespread use of these drugs, their stability and action mechanism studies have also attracted the attention of many researchers. This review focuses on the action mechanism, metabolites and degradation products of these antiviral drugs (FAV, RDV and LPV) and demonstrates various methods for their quantification and discrimination in the different biological samples. Herein, the instrumental methods for analysis of the main form of drugs or their metabolite and degradation products are classified into two types: optical and chromatography methods which the last one in combination with various detectors provides a powerful method for routine and stability analyses. Some representative studies are reported in this review and the details of them are carefully explained. It is hoped that this review will be a good guideline study and provide a better understanding of these drugs from the aspects investigated in this study.

COVID-19: On the threshold of the fifth year. The situation in Spain

Despite having emerged from pandemic status, the incidence of COVID-19 episodes has recently increased in Spain, including pediatric cases and admissions to Intensive Care Units. Several recombinant variants are circulating among us, particularly XBB arising from two Omicron BA.2 sublineages with mutations in the genes encoding the spicule proteins that could increase binding to the ACE2 receptor and be more prone to immune escape. Faced with these, 3 pharmaceutical companies have developed vaccines adapted to the XBB.1.5 sublineage that are already available for administration in our setting with risks that should not be different from those of previous mRNA vaccines and with clearly favorable benefit/risk ratios. They should be applied to patients with potential for poor COVID-19 evolution and to collectives that have a particular relationship of proximity with them. Their application should be understood not only from a perspective of individual convenience but also from that of collective responsibility. The most convenient seems to be a simultaneous immunization of COVID-19 and influenza in our environment. In the therapeutic aspect, there is little to expect right now from antisera, but the already known antiviral drugs are still available and indicated, although their efficacy will have to be reevaluated due to their impact on populations that are mostly immunized and with a better prognosis than in the past. In our opinion, it is necessary to continue to make a reasonable and timely use of masks and other non-pharmacological means of protection.

Modeling drug-induced mitochondrial toxicity with human primary cardiomyocytes

Mitochondrial toxicity induced by therapeutic drugs is a major contributor for cardiotoxicity, posing a serious threat to pharmaceutical industries and patients' lives. However, mitochondrial toxicity testing is not incorporated into routine cardiac safety screening procedures. To accurately model native human cardiomyocytes, we comprehensively evaluated mitochondrial responses of adult human primary cardiomyocytes (hPCMs) to a nucleoside analog, remdesivir (RDV). Comparison of their response to human pluripotent stem cell-derived cardiomyocytes revealed that the latter utilized a mitophagy-based mitochondrial recovery response that was absent in hPCMs. Accordingly, action potential duration was elongated in hPCMs, reflecting clinical incidences of RDV-induced QT prolongation. In a screen for mitochondrial protectants, we identified mitochondrial ROS as a primary mediator of RDV-induced cardiotoxicity. Our study demonstrates the utility of hPCMs in the detection of clinically relevant cardiac toxicities, and offers a framework for hPCM-based high-throughput screening of cardioprotective agents.

Analysis of the SARS-CoV-2 nsp12 P323L/A529V mutations: coeffect in the transiently peaking lineage C.36.3 on protein structure and response to treatment in Egyptian records

SARS-CoV-2 nsp12, the RNA-dependent RNA-polymerase plays a crucial role in virus replication. Monitoring the effect of its emerging mutants on viral replication and response to antiviral drugs is important. Nsp12 of two Egyptian isolates circulating in 2020 and 2021 were sequenced. Both isolates included P323L, one included the A529V. Tracking A529V mutant frequency, it relates to the transience peaked C.36.3 variant and its parent C.36, both peaked worldwide on February-August 2021, enlisted as high transmissible variants under investigation (VUI) on May 2021. Both Mutants were reported to originate from Egypt and showed an abrupt low frequency upon screening, we analyzed all 1104 nsp12 Egyptian sequences. A529V mutation was in 36 records with an abrupt low frequency on June 2021. As its possible reappearance might obligate actions for a candidate VUI, we analyzed the predicted co-effect of P323L and A529V mutations on protein stability and dynamics through protein structure simulations. Three available structures for drug-nsp12 interaction were used representing remdesivir, suramin and favipiravir drugs. Remdesivir and suramin showed an increase in structure stability and considerable change in flexibility while favipiravir showed an extreme interaction. Results predict a favored efficiency of the drugs except for favipiravir in case of the reported mutations.

Stably-Inverted Apical-Out Human Upper Airway Organoids for SARS-CoV-2 Infection and Therapeutic Testing

Apical-out organoids produced through eversion triggered by extra-organoid extracellular matrix (ECM) removal or degradation are generally small, structurally variable, and limited for viral infection and therapeutics testing. This work describes ECM-encapsulating, stably-inverted apical-out human upper airway organoids (AORBs) that are large (~500 μm diameter), consistently spherical, recapitulate in vivo-like cellular heterogeneity, and maintain their inverted morphology for over 60 days. Treatment of AORBs with IL-13 skews differentiation towards goblet cells and the apical-out geometry allows extra-organoid mucus collection. AORB maturation for 14 days induces strong co-expression of ACE2 and TMPRSS2 to allow high-yield infection with five SARS-CoV-2 variants. Dose-response analysis of three well-studied SARS-CoV-2 antiviral compounds [remdesivir, bemnifosbuvir (AT-511), and nirmatrelvir] shows AORB antiviral assays to be comparable to gold-standard air-liquid interface cultures, but with higher throughput (~10-fold) and fewer cells (~100-fold). While this work focuses on SARS-CoV-2 applications, the consistent AORB shape and size, and one-organoid-per-well modularity broadly impacts in vitro human cell model standardization efforts in line with economic imperatives and recently updated FDA regulation on therapeutic testing.

Coagulopathy and adverse outcomes in hospitalized patients with COVID-19: results from the NOR-Solidarity trial

Background

Several studies have examined parameters of increased thrombogenicity in COVID-19, but studies examining their association with long-term outcome and potential effects of antiviral agents in hospitalized patients with COVID-19 are scarce.

Objectives

To evaluate plasma levels of hemostatic proteins during hospitalization in relation to disease severity, treatment modalities, and persistent pulmonary pathology after 3 months.

Methods

In 165 patients with COVID-19 recruited into the NOR-Solidarity trial (NCT04321616) and randomized to treatment with hydroxychloroquine, remdesivir, or standard of care, we analyzed plasma levels of hemostatic proteins during the first 10 days of hospitalization (n = 160) and at 3 months of follow-up (n = 100) by enzyme immunoassay.

Results

Our main findings were as follows: (i) tissue plasminogen activator (tPA) and tissue factor pathway inhibitor (TFPI) were increased in patients with severe disease (ie, the combined endpoint of respiratory failure [Po2-to-FiO2 ratio, <26.6 kPa] or need for treatment at an intensive care unit) during hospitalization. Compared to patients without severe disease, tPA levels were a median of 42% (P < .001), 29% (P = .002), and 36% (P = .015) higher at baseline, 3 to 5 days, and 7 to 10 days, respectively. For TFPI, median levels were 37% (P = .003), 25% (P < .001), and 10% (P = .13) higher in patients with severe disease at these time points, respectively. No changes in thrombin-antithrombin complex; alpha 2-antiplasmin; a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13; or antithrombin were observed in relation to severe disease. (ii) Patients treated with remdesivir had lower levels of TFPI than those in patients treated with standard of care alone. (iii) TFPI levels during hospitalization, but not at 3 months of follow-up, were higher in those with persistent pathology on chest computed tomography imaging 3 months after hospital admission than in those without such pathology. No consistent changes in thrombin-antithrombin complex, alpha 2-antiplasmin, ADAMTS-13, tPA, or antithrombin were observed in relation to pulmonary pathology at 3 months of follow-up.

Conclusion

TFPI and tPA are associated with severe disease in hospitalized patients with COVID-19. For TFPI, high levels measured during the first 10 days of hospitalization were also associated with persistent pulmonary pathology even 3 months after hospital admittance.

Prescribing of antivirals for COVID-19 in a South Australian local health network according to statewide guidelines

Antiviral drugs were rapidly implemented into clinical practice for the treatment of high-risk patients with COVID-19, prompting the development of statewide guidelines. This South-Australian study reviewed guideline adherence, assessed prescribing patterns and highlighted the inappropriate management of relative drug-drug interactions and dosing for renal function. Additionally, it evaluated the impact of inappropriate antiviral drug use and suggested methods to improve quality use of medicines.

Outpatient Intravenous Remdesivir to Prevent Progression to Severe COVID-19: An Observational Study from a Greek Hospital

BACKGROUND

Remdesivir, a viral RNA polymerase inhibitor, has been a powerful weapon in the battle against the SARS-CoV-2 pandemic. Originally approved for use in hospitalized patients, remdesivir improves clinical outcomes in patients with moderate to severe coronavirus disease 2019 (COVID-19). After proving efficacious in hospitalized patients, its use was approved in early disease for symptomatic, non-hospitalized patients that present risk factors for progression to severe disease.

OBJECTIVE

To evaluate whether administration of the antiviral medication remdesivir at an outpatient basis has an effect on hospital admissions of patients presenting with SARSCoV- 2 infection.

METHODS

We conducted an observational clinical trial involving 107 non-hospitalized COVID-19 patients who attended the emergency department of a third-level greek hospital seeking care for symptoms appearing within the previous 5 days and who had at least one risk factor for progression to severe disease. After arterial blood gas evaluation, eligible patients received intravenous remdesivir at a dose of 200 mg on day 1 and 100 mg on days 2 and 3. The efficacy endpoint was set as COVID-19-related hospitalization or death in the next 14 days.

RESULTS

A total of 107 patients (57.0% men) participated in the study, 51 (47.7%) of them fully vaccinated. Most prevalent were age ≥ 60 years old, cardiovascular/cerebrovascular disease, immunosuppression or malignancy, obesity, diabetes mellitus, and chronic lung disease. All patients enrolled completed the 3-day course, with a total of 3 out of 107 patients (2.8%) eventually having a COVID-19-related hospitalization by day 14, while no deaths were reported by day 14.

CONCLUSION

Among non-hospitalized patients with at least one risk factor for progression to severe COVID-19, a 3-day course of intravenous remdesivir yielded favourable results.

Remdesivir Reduced Mortality in Immunocompromised Patients Hospitalized for COVID-19 Across Variant Waves: Findings From Routine Clinical Practice

BACKGROUND

Immunocompromised patients are at high risk of severe coronavirus disease 2019 (COVID-19) and death, yet treatment strategies for immunocompromised patients hospitalized for COVID-19 reflect variations in clinical practice. In this comparative effectiveness study, we investigated the effect of remdesivir treatment on inpatient mortality among immunocompromised patients hospitalized for COVID-19 across all variants of concern (VOC) periods.

METHODS

Data for immunocompromised patients hospitalized for COVID-19 between December 2020 and April 2022 were extracted from the US PINC AITM Healthcare Database. Patients who received remdesivir within 2 days of hospitalization were matched 1:1 using propensity score matching to patients who did not receive remdesivir. Additional matching criteria included admission month, age group, and hospital. Cox proportional hazards models were used to examine the effect of remdesivir on risk of 14- and 28-day mortality during VOC periods.

RESULTS

A total of 19 184 remdesivir patients were matched to 11 213 non-remdesivir patients. Overall, 11.1% and 17.7% of remdesivir patients died within 14 and 28 days, respectively, compared with 15.4% and 22.4% of non-remdesivir patients. Remdesivir was associated with a reduction in mortality at 14 (hazard ratio [HR], 0.70; 95% confidence interval, .62-.78) and 28 days (HR, 0.75; 95% CI, .68-.83). The survival benefit remained significant during the pre-Delta, Delta, and Omicron periods.

CONCLUSIONS

Prompt initiation of remdesivir in immunocompromised patients hospitalized for COVID-19 is associated with significant survival benefit across all variant waves. These findings provide much-needed evidence relating to the effectiveness of a foundational treatment for hospitalized COVID-19 patients among a high-risk population.

Remdesivir-Induced Bradycardia and Mortality in SARS-CoV-2 Infection, Potential Risk Factors Assessment: A Systematic Review and Meta-Analysis

Background: The efficacy of remdesivir in reducing disease severity among COVID-19-infected patients has been established, but concerns have emerged regarding the potential side effects of bradycardia. The aim of this study was to investigate the association between remdesivir-induced bradycardia and mortality, while also identifying the related risk factors. Materials and methods: The PubMed/Medline, Cochrane Central and ClinicalTrials.gov databases were searched. Randomized controlled trials and prospective or retrospective cohort studies were included (through 14 July 2023). The random-effects model was implemented using Comprehensive Meta-Analysis software version 3.0 to examine the outcomes. Results: A total of 12 prospective or retrospective studies involving 7674 patients were analyzed. The primary outcomes revealed a significant association between remdesivir administration and bradycardia development (Odds ratio = 2.556, 95% CI = 2.049-3.188, p < 0.001). However, no statistically significant increase in the mortality rate was observed among patients with bradycardia during remdesivir treatment (Odds ratio = 0.872, 95% CI = 0.483-1.576, p = 0.651). The secondary outcome demonstrated a significant association between chronic kidney disease (CKD) and remdesivir-induced bradycardia (OR: 1.251, 95% CI: 1.003-1.561, p = 0.047). Moreover, patients with obesity (OR = 1.347, 95% CI = 1.098-1.652, p = 0.004) were more likely to experience remdesivir-induced bradycardia. Conclusions: Although a higher risk of bradycardia occurred during remdesivir treatment, the occurrence of remdesivir-induced bradycardia did not lead to higher mortality. Our study also identified patients with obesity and CKD as high-risk subgroups for experiencing bradycardia during remdesivir treatment.

Remdesivir therapy for severe pediatric COVID-19 in Singapore: A single-center retrospective observational cohort study

Background and Aims

There is a paucity of information on remdesivir (RDV) use in severe pediatric coronavirus disease 2019 (COVID-19). We aimed to explore the effectiveness of RDV as the cumulative proportion of pediatric COVID-19 patients deescalated from Day 5 of high dependency or intensive care unit (HD/ICU).

Methods

All children ≤18 years admitted to Singapore's largest pediatric hospital from January 1, 2020 to March 18, 2022 were reviewed retrospectively. Patients were included if they were positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on reverse transcriptase polymerase chain reaction, required oxygen, and HD/ICU care. The characteristics and outcomes of those who received RDV or not (no-RDV) were compared.

Results

We reviewed 15 children with a median age of 2.5 years (interquartile range [IQR]: 0.8-11.0), of which 7 (46.7%) received RDV. There was no difference in cumulative proportion of children deescalated from Day 5 of HD/ICU care in the RDV versus the no-RDV group (5/7, 70% vs. 7/8, 87.5%, p = 0.57). The RDV versus no-RDV group had higher disease severity, that is, WHO Ordinal Scale scores (median 6, IQR: 5-7 vs. 5, IQR: 4-5, p = 0.03), higher procalcitonin levels (ug/L) (median 4.31, IQR: 0.8-24.2 vs. 0.12, IQR: 0.09-0.26, p = 0.02), and longer HD/ICU care days (median 5, IQR: 4-9, vs. 1, IQR: 1-4, p = 0.01). There was no significant difference in hospitalization days. There were no adverse events directly attributable to RDV. None died from COVID-19 infection.

Conclusion

Our observational analysis was unable to detect any clear benefit of RDV in terms of reducing duration in HD/ICU. RDV was well-tolerated in children with severe COVID-19.

Quantification of GS-441524 concentration in feline plasma using high performance liquid chromatography with fluorescence detection

The adenosine analogue GS-441524 has demonstrated efficacy in treatment of feline infectious peritonitis (FIP). With no commercially registered formulations of GS-441524 available, global focus shifted to its pro-drug remdesivir, as it became more accessible throughout the COVID-19 pandemic. This study developed and validated a simple liquid chromatography equipped with a fluorescence detector to quantify plasma concentrations of GS-441524 applicable for routine therapeutic monitoring of remdesivir or GS-441524 therapy for FIP infected cats. A Waters X-Bridge C18, 5 µm, 150 × 4.6 mm, column was used and mixtures of 20 mM ammonium acetate (pH 4.5) with acetonitrile of 5% and 70% were prepared for gradient mobile phase. With a simple protein precipitation using methanol to clean plasma sample, GS-441524 was monitored at excitation and emission wavelengths of 250 nm and 475 nm, respectively. Using an external standard, the lowest and highest limits of quantification were 19.5 ng/mL to 10,000 ng/mL, respectively. The intra- and inter day trueness of the quality controls (QCs) were within 10% of their nominal concentrations and intra- and inter day precision of the QCs (expressed as the coefficient of variation) ranged from 1.7 to 5.7%, This assay was able to quantify plasma trough levels of GS-441524 (23.7-190.1 ng/mL) after the administration of remdesivir (9.9-15.0 mg/kg BW, IV or SC) in FIP cats (n = 12). Accordingly, this study generated an alternative and cost-effective way to quantify GS-441524 in feline biological fluids at least up to 24 hr after administrations of remdesivir.

COVID-19 Mortality and Remdesivir - A Retrospective Cohort in Intensive Care Setting

BACKGROUND

Remdesivir is a broad-spectrum antiviral drug that received emergency use authorization in the first wave of the COVID-19 pandemic. However, its effectiveness in preventing mortality in COVID-19 patients who required intensive care was unclear.

PATIENTS AND METHODS

We retrospectively analyzed clinical data of 302 patients from intensive care units of a quaternary care center with moderate to severe COVID-19 illness and followed them until discharge between March 2020 and February 2021. Participants who received at least five doses of Remdesivir were compared against participants who received standard care. The primary outcome was all-cause mortality. Secondary outcomes included invasive mechanical ventilation, clinical worsening, and intensive care stay.

RESULTS

Remdesivir use was not associated with all-cause mortality in this cohort (age and sex-adjusted OR = 0.76, 95% CI 0.4 -1.5, p = 0.409). However, when stratified for clinical severity and steroid use, Remdesivir demonstrated a strong negative association with all-cause mortality in severely ill patients (OR 0.3, 95% CI 0.1 - 0.6, p = 0.003) or when used along with intravenous Methylprednisolone (Infusion/Bolus, OR 0.2/0.3, 95% CI 0.1 - 0.9 p = 0.06). Remdesivir use was not significantly associated with invasive mechanical ventilation or clinical worsening but with prolonged ICU stay.

CONCLUSION

While Remdesivir use may not affect all-cause mortality in moderate to severely ill COVID-19 ICU patients, it may still benefit severely ill patients or when used with intravenous steroids. However, the limitations of the present study necessitate a randomized controlled trial to test this combined intervention strategy.

Molecular docking analysis of quercetin with known CoVid-19 targets

Combat and care during CoVid-19 was non-trivial. Therefore, it is of interest to use the pharmacologically active plant component quercetin for the treatment of CoVid-19. Quercetin exhibits favourable ADMET values and abides by Lipinski's rule of five. When quercetin and remdesivir were positioned in relation to the CoVid-19 targets, quercetin exhibited a greater propensity for binding and H-bond interaction in their molecular interactions. Thus, the quercetin molecule can be used to manage CoVid-19.

Efficacy and Safety of Remdesivir in Hospitalized Pediatric COVID-19: A Retrospective Case-Controlled Study

Introduction

While most children experience mild coronavirus disease 2019 (COVID-19) infections, a minority of cases progress to severe or critical illness. This study aimed to assess the efficacy and safety of Remdesivir (RDV) therapy in children with moderate to severe COVID-19, enhancing clinical decision-making and expanding our understanding of antiviral treatments for pediatric patients.

Methods

The study included 60 patients, 38 receiving RDV treatment and 22 serving as the control group. Data was collected retrospectively from January 2021 to January 2022 through electronic hospital records.

Results

Regarding the main clinical symptoms reported, most patients experienced Upper Respiratory Tract Infections (93.3%), indicating respiratory involvement. Additional symptoms included Central Nervous System (11.7%) and Gastrointestinal (10.0%). Among the 38 cases in the RDV group included in the study, the adverse effects associated with using RDV: Hypoalbuminemia in 19 cases (50.0%) and anemia in 18 cases (47.4%), making them the most common adverse effects. Only one case in the RDV group experienced non-RDV-related death with a different clinical diagnosis. The results showed that RDV treatment was well-tolerated in pediatric patients, with no significant differences in hospital stay and oxygen treatment compared to the control group with P values (0.2, 0.18), respectively.

Conclusion

The outcomes indicate that Remdesivir may represent a safe and therapeutic choice for children with coronavirus disease 2019 (COVID-19).

Remdesivir Derivative VV116 Is a Potential Broad-Spectrum Inhibitor of Both Human and Animal Coronaviruses

Coronaviruses represent a significant threat to both human and animal health, encompassing a range of pathogenic strains responsible for illnesses, from the common cold to more severe diseases. VV116 is a deuterated derivative of Remdesivir with oral bioavailability that was found to potently inhibit SARS-CoV-2. In this work, we investigated the broad-spectrum antiviral activity of VV116 against a variety of human and animal coronaviruses. We examined the inhibitory effects of VV116 on the replication of the human coronaviruses HCoV-NL63, HCoV-229E, and HCoV-OC43, as well as the animal coronaviruses MHV, FIPV, FECV, and CCoV. The findings reveal that VV116 effectively inhibits viral replication across these strains without exhibiting cytotoxicity, indicating its potential for safe therapeutic use. Based on the results of a time-of-addition assay and an rNTP competitive inhibition assay, it is speculated that the inhibitory mechanism of VV116 against HCoV-NL63 is consistent with its inhibition of SARS-CoV-2. Our work presents VV116 as a promising candidate for broad-spectrum anti-coronavirus therapy, with implications for both human and animal health, and supports the expansion of its therapeutic applications as backed by detailed experimental data.

Clinical Antiviral Efficacy of Remdesivir in Coronavirus Disease 2019: An Open-Label, Randomized Controlled Adaptive Platform Trial (PLATCOV)

BACKGROUND

Uncertainty over the therapeutic benefit of parenteral remdesivir in coronavirus disease 2019 (COVID-19) has resulted in varying treatment guidelines.

METHODS

In a multicenter open-label, controlled, adaptive, pharmacometric platform trial, low-risk adult patients with early symptomatic COVID-19 were randomized to 1 of 8 treatment arms including intravenous remdesivir (200 mg followed by 100 mg daily for 5 days) or no study drug. The primary outcome was the rate of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) clearance (estimated under a linear model fit to the daily log10 viral densities, days 0-7) in standardized duplicate oropharyngeal swab eluates, in a modified intention-to-treat population. This ongoing adaptive trial is registered at ClinicalTrials.gov (NCT05041907).

RESULTS

The 2 study arms enrolled 131 patients (remdesivir n = 67, no study drug n = 64) and estimated viral clearance rates from a median of 18 swab samples per patient (a total of 2356 quantitative polymerase chain reactions). Under the linear model, compared with the contemporaneous control arm (no study drug), remdesivir accelerated mean estimated viral clearance by 42% (95% credible interval, 18%-73%).

CONCLUSIONS

Parenteral remdesivir accelerates viral clearance in early symptomatic COVID-19. Pharmacometric assessment of therapeutics using the method described can determine in vivo clinical antiviral efficacy rapidly and efficiently.

Multidrug-resistant mutations to antiviral and antibody therapy in an immunocompromised patient infected with SARS-CoV-2

BACKGROUND

Antiviral and antibody therapies for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are being recommended for high-risk patients, but the potential for the development of multidrug-resistant mutations in immunocompromised patients is unclear.

METHODS

To investigate the treatment course in cases of prolonged viral shedding in an immunocompromised patient with SARS-CoV-2 infection, we conducted longitudinal measurements of laboratory tests, chest computed tomography (CT) image evaluations, antibody titers, and antigen levels in nasopharyngeal swabs. Furthermore, we performed whole-genome sequencing and digital PCR analysis to examine the mechanisms of drug resistance.

FINDINGS

We present a case of a 65-year-old man with a history of malignant lymphoma who was treated with multiple antiviral and antibody therapies, including sotrovimab, remdesivir, paxlovid (nirmatrelvir/ritonavir), and molnupiravir. Initially, viral antigen levels decreased after treatments. However, after the virus rebounded, the patient showed no virologic response. The viral genome analysis revealed a single Omicron subvariant (BA.1.1), which evolved within the host during the disease progression. The viruses had acquired multiple resistance mutations to nirmatrelvir (3 chymotrypsin-like protease [3CLpro] E166 A/V), sotrovimab (spike P337L and E340K), and remdesivir (RNA-dependent RNA polymerase [RdRp] V166L).

CONCLUSIONS

Our results indicate that viruses with multidrug-resistant mutations and survival fitness persist in the infected subpopulation after drug selection pressure.

FUNDING

This study was supported by the JSPS KAKENHI Early-Career Scientists 18K16292 (Y.H.), Grant-in-Aid for Scientific Research (B) 20H03668 and 23H02955 (Y.H.), the YASUDA Medical Foundation (Y.H.), the Uehara Memorial Foundation (Y.H.), the Takeda Science Foundation (Y.H.), and Kato Memorial Bioscience Foundation (Y.H.).

Y-site Injection Physical Compatibility of Remdesivir with Select Intravenous Drugs Used in Palliative Care and for Treating Coronavirus Disease 2019

BACKGROUND

No compatibility tests are available for remdesivir other than 0.9% sodium chloride. In this study, we aimed to evaluate the physical compatibility of remdesivir with drugs used in palliative care and COVID-19 treatment.

METHODS

Remdesivir was tested for compatibility with 10 different drugs (fentanyl, morphine, hydromorphone, oxycodone, heparin, furosemide, octreotide, acetated Ringer's injection, 2-in-1 peripheral parenteral nutrition, and 2-in-1 total parenteral nutrition). Remdesivir was formulated to a final concentration of 1 mg/mL, and the other drugs were prepared at clinical concentrations. Three test solutions were used for compatibility testing, with remdesivir and the target drugs compounded in a 1:1 ratio. Appearance measurements, including Tyndall effect, turbidity, and pH, were performed immediately after mixing and at 1 h and 4 h after mixing. Changes in appearance, including the Tyndall effect, turbidity (turbidity change of ≥ 0.5 nephelometric turbidity unit [NTU] based on control solution for each test drug), and pH (a change of ≥ 10% based on the pH immediately after mixing) were used to determine physical compatibility.

RESULTS

All the drugs tested were compatible with remdesivir. The combination of remdesivir and furosemide produced the highest turbidity (0.23 ± 0.03 NTU) 1 h after mixing. The lowest and highest pH values were observed at 4 h after mixing for the combinations of remdesivir and morphine (3.23 ± 0.02) and remdesivir and furosemide (8.81 ± 0.06).

CONCLUSIONS

The drugs tested in this study show Y-site physical compatibility with remdesivir.

Viral Resistance Analyses From the Remdesivir Phase 3 Adaptive COVID-19 Treatment Trial-1 (ACTT-1)

BACKGROUND

Remdesivir is approved for treatment of coronavirus disease 2019 (COVID-19) in nonhospitalized and hospitalized adult and pediatric patients. Here we present severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) resistance analyses from the phase 3 ACTT-1 randomized placebo-controlled trial conducted in adult participants hospitalized with COVID-19.

METHODS

Swab samples were collected at baseline and longitudinally through day 29. SARS-CoV-2 genomes were sequenced using next-generation sequencing. Phenotypic analysis was conducted directly on participant virus isolates and/or using SARS-CoV-2 subgenomic replicons expressing mutations identified in the Nsp12 target gene.

RESULTS

Among participants with both baseline and postbaseline sequencing data, emergent Nsp12 substitutions were observed in 12 of 31 (38.7%) and 12 of 30 (40.0%) participants in the remdesivir and placebo arms, respectively. No emergent Nsp12 substitutions in the remdesivir arm were observed in more than 1 participant. Phenotyping showed low to no change in susceptibility to remdesivir relative to wild-type Nsp12 reference for the substitutions tested: A16V (0.8-fold change in EC50), P323L + V792I (2.2-fold), C799F (2.5-fold), K59N (1.0-fold), and K59N + V792I (3.4-fold).

CONCLUSIONS

The similar rate of emerging Nsp12 substitutions in the remdesivir and placebo arms and the minimal change in remdesivir susceptibility among tested substitutions support a high barrier to remdesivir resistance development in COVID-19 patients. Clinical Trials Registration. NCT04280705.

Safety and Efficacy of Combination Therapy of Remdesivir, Baricitinib, and High-dose Steroids in Patients Hospitalized with Moderate to Severe COVID-19

Objective Dexamethasone, remdesivir (REM), and baricitinib (BAR) are commonly used to treat coronavirus disease 2019 (COVID-19). High-dose steroids have also been reported to be well tolerated, even when used in combination with multiple drugs. In this retrospective study, we assessed the safety and therapeutic efficacy of a three-drug combination of high-dose steroids, REM, and BAR in hospitalized COVID-19 patients. Methods We retrospectively evaluated the safety and efficacy of three-drug combination therapy. Patients We evaluated 107 patients hospitalized with moderate or severe COVID-19 who underwent 3-drug combination therapy with high-dose steroids (80 mg of methylprednisolone or more, REM, and BAR) in our institution from December 2020 to June 2021. The mean age was 62.1±13.7 years old, and 71.2% were men. The severity of the study patients was as follows: 18 (16.8%) with an 8-category ordinal score of 4, 84 (78.5%) with a score of 5, and 5 (4.7%) with a score of 6. Results The frequency of high-grade adverse events was low, except for hyperglycemia (n=59, 45.8%). The median duration from symptom onset to the start of three-drug combination therapy was eight days. All but one of the patients treated with the combination therapy improved. The median time to improvement by 1 category of the eight-category ordinal score was 6 days, and the 28-day mortality was 0.9%. Conclusion This study showed the safety profile of three-drug combination therapy of high-dose steroids, REM, and BAR in moderate to severe COVID-19 patients. The three-drug combination therapy is well tolerated and has the potential to prevent exacerbation of severity.

The Burden of COVID-19 in Adult Patients With Hematological Malignancies: A Single-center Experience After the Implementation of Mass-vaccination Programs Against SARS-CoV-2

BACKGROUND/AIM

Despite the widespread mass-vaccination programs worldwide and the continuing evolution of COVID-19 therapeutics, the burden of SARS-CoV-2 infection in patients with hematological malignancies (HM) remains elusive. The aim of the present study was to assess the clinical characteristics, outcomes and therapeutic strategies applied in HM patients hospitalized during the post-vaccine period in Greece.

PATIENTS AND METHODS

From June 2021 to October 2022, 60 HM patients with COVID-19 were retrospectively analyzed. Exploratory end-points included the incidence of intubation, probability of recovery, mortality, and duration of remdesivir (RDV) administration.

RESULTS

Overall, mechanical ventilation (MV) was required for five patients and crude mortality was 8.3%. HM of lymphocytic origin (p=0.035) and obesity (p=0.03) were the main determinants of the risk of intubation and among several laboratory markers, only LDH>520 IU/l was proven to be an independent MV predictor (p=0.038). The number of co-existing comorbidities (p=0.05) and disease severity on admission (p<0.001) were found to rule the probability of recovery, and dexamethasone was associated with worse prognosis, particularly in patients with mild/moderate COVID-19. RDV was administered to the entire cohort, of whom 38 were managed with an extended course. In the multivariate analysis, patients with HM of lymphocytic origin were more likely to receive RDV for more than five days (p=0.002).

CONCLUSION

Our study emphasizes the frailty of HM patients, even in the era of Omicron-variant predominance, and underlines the need to optimize therapy.

Remdesivir inhibits Porcine epidemic diarrhea virus infection in vitro

Porcine Epidemic Diarrhea Virus (PEDV) is a highly contagious and pathogenic virus that causes symptoms such as diarrhea, vomiting, weight loss, and even death in piglets. Due to its high transmission rate, PEDV has resulted in significant global losses. Although some vaccines have been developed and utilized to prevent PEDV, their effectiveness is limited due to the virus's mutations. Therefore, it is imperative to investigate new strategies to combat PEDV. Remdesivir, a classic antiviral drug for coronaviruses, has been proven in our experiment to effectively suppress PEDV replication in Vero and LLC-PK1 cells. Additionally, the cell experiment demonstrated its direct inhibition of PEDV RNA-dependent RNA polymerase (RdRp) enzyme activity. Molecular docking simulations were employed to predict the binding site of remdesivir and PEDV RdRp. Moreover, we observed that remdesivir does not impact the production of inflammatory factors and exhibits antagonistic effects with exogenous nucleosides. Furthermore, we conducted RNA-Seq analysis to investigate the global changes in transcriptome of infected cells treated with remdesivir. Overall, our findings indicate that remdesivir holds promise as a potential candidate for the treatment of PEDV infection.