What is the role of remdesivir in patients with COVID-19?

PURPOSE OF REVIEW: COVID-19 represents an unprecedented public health crisis caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The antiviral remdesivir is one component of treating COVID-19. Unfortunately, the trials evaluating remdesivir have reported mixed results, leading to uncertainty on when to use remdesivir. This review discusses the trials evaluating the efficacy of remdesivir for COVID-19 and other supporting data to help inform the role of remdesivir in patients with COVID-19. RECENT FINDINGS: Since the start of the pandemic, there have been four randomized trials of remdesivir in treating patients hospitalized with COVID-19. More recently, extensive observational studies have provided supportive data. SUMMARY: The majority of trials evaluating remdesivir suggest that remdesivir is effective in the treatment of patients hospitalized with COVID-19. Although there may be a benefit in some subgroups more than others, there is insufficient data to make definitive statements about benefits or lack of benefits in particular groups. Remdesivir has demonstrated clinical benefits such as decreased time in the hospital, lower progression to mechanical ventilation, and decreased utilization of other hospital resources; it is unclear if it reduces mortality, but one randomized controlled trial suggested possible survival benefits. Based on the data available, remdesivir has been approved (or authorized for early use) in 48 countries.

Energetic vs. entropic stabilization between a Remdesivir analogue and cognate ATP upon binding and insertion into the active site of SARS-CoV-2 RNA dependent RNA polymerase.

SARS-CoV-2 RNA dependent RNA polymerase (RdRp) serves as a highly promising antiviral drug target such as for a Remdesivir nucleotide analogue (RDV-TP or RTP). In this work, we mainly used alchemical all-atom simulations to characterize relative binding free energetics between the nucleotide analogue RTP and natural cognate substrate ATP upon initial binding and pre-catalytic insertion into the active site of SARS-CoV-2 RdRp. Natural non-cognate substrate dATP and mismatched GTP were also examined for computation control. We first identified significant differences in dynamical responses between nucleotide initial binding and subsequent insertion configurations to the open and closed active sites of the RdRp, respectively, though the RdRp protein conformational changes between the active site's open and closed states are subtle. Our alchemical simulations indicated that upon initial binding (active site open), RTP and ATP show similar binding free energies to the active sites while in the insertion state (active site closed), ATP is more stabilized (∼-2.4 kcal mol-1) than RTP in free energetics. Additional analyses show, however, that RTP is more stabilized in binding energetics than ATP, in both the insertion and initial binding states, with RTP more stabilized due to the electrostatic energy in the insertion state and due to vdW energy in the initial binding state. Hence, it appears that natural cognate ATP still excels at association stability with the RdRp active site due to that ATP maintains sufficient flexibilities e.g., in base pairing with the template, which exemplifies an entropic contribution to the cognate substrate stabilization. These findings highlight the importance of substrate flexibilities in addition to energetic stabilization in antiviral nucleotide analogue design.

Remdesivir for the Treatment of Covid-19 - Final Report.

BACKGROUND: Although several therapeutic agents have been evaluated for the treatment of coronavirus disease 2019 (Covid-19), no antiviral agents have yet been shown to be efficacious. METHODS: We conducted a double-blind, randomized, placebo-controlled trial of intravenous remdesivir in adults who were hospitalized with Covid-19 and had evidence of lower respiratory tract infection. Patients were randomly assigned to receive either remdesivir (200 mg loading dose on day 1, followed by 100 mg daily for up to 9 additional days) or placebo for up to 10 days. The primary outcome was the time to recovery, defined by either discharge from the hospital or hospitalization for infection-control purposes only. RESULTS: A total of 1062 patients underwent randomization (with 541 assigned to remdesivir and 521 to placebo). Those who received remdesivir had a median recovery time of 10 days (95% confidence interval [CI], 9 to 11), as compared with 15 days (95% CI, 13 to 18) among those who received placebo (rate ratio for recovery, 1.29; 95% CI, 1.12 to 1.49; P<0.001, by a log-rank test). In an analysis that used a proportional-odds model with an eight-category ordinal scale, the patients who received remdesivir were found to be more likely than those who received placebo to have clinical improvement at day 15 (odds ratio, 1.5; 95% CI, 1.2 to 1.9, after adjustment for actual disease severity). The Kaplan-Meier estimates of mortality were 6.7% with remdesivir and 11.9% with placebo by day 15 and 11.4% with remdesivir and 15.2% with placebo by day 29 (hazard ratio, 0.73; 95% CI, 0.52 to 1.03). Serious adverse events were reported in 131 of the 532 patients who received remdesivir (24.6%) and in 163 of the 516 patients who received placebo (31.6%). CONCLUSIONS: Our data show that remdesivir was superior to placebo in shortening the time to recovery in adults who were hospitalized with Covid-19 and had evidence of lower respiratory tract infection. (Funded by the National Institute of Allergy and Infectious Diseases and others; ACTT-1 ClinicalTrials.gov number, NCT04280705.).

Coronavirus disease 2019 management.

PURPOSE OF REVIEW: Coronavirus disease 2019 (COVID-19) is an acute multisystem disease caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Investigations are ongoing in the search for effective therapeutics, with clinical approaches evolving based upon such evidence. RECENT FINDINGS: The antiviral agent, remdesivir, and the immunomodulator, dexamethasone, are the first therapeutics for which there is evidence of efficacy from randomized trials. Subgroup analyses suggest remdesivir is beneficial in hospitalized patients whose severity of illness falls at the lower end of the spectrum, while dexamethasone is more beneficial in hospitalized patients whose severity of illness falls at the higher end of the spectrum. We recommend that inpatients who require supplemental oxygen but are not mechanically ventilated receive both remdesivir and dexamethasone, and inpatients who require mechanical ventilation receive dexamethasone monotherapy. Additional evidence regarding anti-SARS-CoV-2 antibodies, convalescent plasma, and a variety of antiinterleukin therapies is forthcoming. SUMMARY: The body of evidence related to COVID-19 therapeutics continues to evolve and, as a result, management is likely to change with time. As new evidence is generated and published, the optimal approach to managing patients with COVID-19 should be reconsidered.

USA stockpiling of remdesivir: How should the world respond?

The race to find an effective treatment for coronavirus disease 2019 (COVID-19) is still on, with only two treatment options currently authorized for emergency use and/or recommended for patients hospitalized with severe respiratory symptoms: low-dose dexamethasone and remdesivir. The USA decision to stockpile the latter has resulted in widespread condemnation and in similar action being taken by some other countries. In this commentary we discuss whether stockpiling remdesivir is justified in light of the currently available evidence.

Receptor-binding domain-based SARS-CoV-2 vaccine adjuvanted with cyclic di-adenosine monophosphate enhances humoral and cellular immunity in mice.

Novel adjuvants are highly desired to improve immune responses of SARS-CoV-2 vaccines. This work reports the potential of the stimulator of interferon genes (STING) agonist adjuvant, the cyclic di-adenosine monophosphate (c-di-AMP), in a SARS-CoV-2 vaccine based on the receptor binding domain (RBD). Here, mice immunized with two doses of monomeric RBD adjuvanted with c-di-AMP intramuscularly were found to exhibit stronger immune responses compared to mice vaccinated with RBD adjuvanted with aluminum hydroxide (Al(OH)3 ) or without adjuvant. After two immunizations, consistent enhancements in the magnitude of RBD-specific immunoglobulin G (IgG) antibody response were observed by RBD + c-di-AMP (mean: 15360) compared to RBD + Al(OH)3 (mean: 3280) and RBD alone (n.d.). Analysis of IgG subtypes indicated a predominantly Th1-biased immune response (IgG2c, mean: 14480; IgG2b, mean: 1040, IgG1, mean: 470) in mice vaccinated with RBD + c-di-AMP compared to a Th2-biased response in those vaccinated with RBD + Al(OH)3 (IgG2c, mean: 60; IgG2b: n.d.; IgG1, mean: 16660). In addition, the RBD + c-di-AMP group showed better neutralizing antibody responses as determined by pseudovirus neutralization assay and by plaque reduction neutralization assay with SARS-CoV-2 wild type. Moreover, the RBD + c-di-AMP vaccine promoted interferon-γ secretion of spleen cell cultures after RBD stimulation. Furthermore, evaluation of IgG-antibody titers in aged mice showed that di-AMP was able to improve RBD-immunogenicity at old age after 3 doses (mean: 4000). These data suggest that c-di-AMP improves immune responses of a SARS-CoV-2 vaccine based on RBD, and would be considered a promising option for future COVID-19 vaccines.

Remdesivir-induced conduction abnormalities: A molecular model-based explanation.

Purpose: Remdesivir use in COVID-19 is associated with cardiac conduction abnormalities from unclear mechanisms. A proposed mechanism is the bioaccumulation of the intermediate metabolite GS-441524 resulting in exogenous activation of cardiac adenosine A1 due to the structural similarity between adenosine and GS-441524. The prolonged half-life of GS-441524 can result in sustained activation of adenosine A1 receptors. In this study, we used molecular modeling of adenosine, GS-441524 and the adenosine A1 receptor to assess the potential mechanistic association of the proposed mechanism. Methods: Adenosine and GS-441524 structures were acquired from the PubChem database. Ligand docking was carried out using UCSF Chimera. Models were chosen based on greatest binding affinity and minimum root mean square deviation. Figures of resulting structural models were prepared using UCSF Chimera or PyMOL 2.3.5. Results: By modeling the interaction between the A1 G protein complex and both adenosine and GS-441524, we found that the proposed mechanism of exogenous A1 receptor activation is feasible based on docking compatibility. Conclusion: The proposed mechanism of exogenous cardiac A1 receptor activation from bioaccumulation of GS-441524 as a cause of observed cardiac conduction abnormalities with the use of remdesivir in COVID-19 is viable. Further studies are needed to assess causality.

Remdesivir and corticosteroids in the treatment of hospitalized COVID-19 patients.

Coronavirus disease 2019 (COVID-19) is a pandemic infection caused by the newly discovered severe acute respiratory syndrome coronavirus 2. Remdesivir (RDV) and corticosteroids are used mainly in COVID-19 patients with acute respiratory failure. The main objective of the study was to assess the effectiveness of remdesivir with and without corticosteroids in the treatment of COVID-19 patients. We conducted a prospective observational study, including adult patients consecutively hospitalized with confirmed COVID-19 and acute respiratory failure. Patients were divided according to treatment strategy: RDV alone versus RDV with corticosteroids. The primary outcome was the time to recovery in both treatment groups. We included 374 COVID-19 adult patients, 184 were treated with RDV, and 190 were treated with RDV and corticosteroid. Patients in the RDV group had a shorter time to recovery in comparison with patients in the RDV plus corticosteroids group at 28 days after admission [11 vs. 16 days (95% confidence Interval 9.7-12.8; 14.9-17.1; p = .016)]. Patients treated with RDV alone had a shorter length of hospital stay. The use of corticosteroids as adjunctive therapy of RDV was not associated with improvement in mortality of COVID-19 patients.

Early administration of remdesivir plus convalescent plasma therapy is effective to treat COVID-19 pneumonia in B-cell depleted patients with hematological malignancies.

Patients with hematological malignancies (HMs) are at a higher risk of developing severe form and protracted course of COVID-19 disease. We investigated whether the combination of viral replication inhibition with remdesivir and administration of anti-SARS-CoV-2 immunoglobulins with convalescent plasma (CP) therapy might be sufficient to treat B-cell-depleted patients with COVID-19. We enrolled 20 consecutive patients with various HMs with profound B-cell lymphopenia and COVID-19 pneumonia between December 2020 and May 2021. All patients demonstrated undetectable baseline anti-SARS-CoV-2 immunoglobulin levels before CP. Each patient received at least a complete course of remdesivir and at least one unit of CP. Previous anti-CD20 therapy resulted in a more prolonged SARS-CoV-2 PCR positivity compared to other causes of B-cell lymphopenia (p = 0.004). Timing of CP therapy showed a significant impact on the clinical outcome. Simultaneous use of remdesivir and CP reduced time period for oxygen weaning after diagnosis (p = 0.017), length of hospital stay (p = 0.007), and PCR positivity (p = 0.012) compared to patients who received remdesivir and CP consecutively. In addition, time from the diagnosis to CP therapy affected the length of oxygen dependency (p < 0.001) and hospital stay (p < 0.0001). In those cases where there were at least 10 days from the diagnosis to plasma administration, oxygen dependency was prolonged vs. patients with shorter interval (p = 0.006). In conclusion, the combination of inhibition of viral replication with passive immunization was proved to be efficient and safe. Our results suggest the clear benefit of early, combined administration of remdesivir and CP to avoid protracted COVID-19 disease among patients with HMs and B-cell lymphopenia.

Remdesivir.

Remdesivir, marketed under the brand name Veklury, is an antiviral drug with a broad spectrum of activity. There were various countries where the use of Remdesivir for the treatment of COVID-19 was authorized during the pandemic. Remdesivir was first designed to treat hepatitis C, but it was later tested for Ebola virus sickness and Marburg virus infections. Remdesivir is a prodrug designed to facilitate the intracellular transport of GS-441524 monophosphate and its subsequent biotransformation into GS-441524 triphosphate, a ribonucleotide analogue inhibitor of viral RNA polymerase. The objective of this chapter is to provide a comprehensive review of Remdesivir (GS-5734), including its nomenclature, physiochemical properties, preparation methods, identification procedures, numerous qualitative and quantitative analytical techniques, ADME profiles, and pharmacological effects. In addition, the chapter provides a variety of chromatographic and spectroscopic techniques for separating brimonidine from other drugs in combination formulations.

Remdésivir chez les patients hospitalisés pour la COVID-19 au Canada: essai clinique randomisé et contrôlé.

CONTEXTE: Le rôle du remdésivir dans le traitement des patients hospitalisés pour la COVID-19 reste imprécis dans un contexte international. L'essai randomisé et contrôlé (ERC) Solidarity de l'Organisation mondiale de la Santé a évalué le remdésivir chez des patients de nombreux pays; le Canada a inscrit des patients dans un protocole élargi de collecte de données: l'essai CATCO (Canadian Treatments for COVID-19). Nous faisons état des observations canadiennes, des données démographiques, des caractéristiques et des indicateurs cliniques qui témoignent de la variabilité des effets d'un système de santé à l'autre. MÉTHODES: Nous avons procédé à un ERC pragmatique à étiquetage en clair dans les hôpitaux canadiens, en collaboration avec l'essai Solidarity. Nous avons procédé à une attribution aléatoire des patients à 10 jours au remdésivir (200 mg par voie intraveineuse [IV] au jour 0, suivis de 100 mg IV par jour) en plus du traitement standard, ou au traitement standard seulement. L'indicateur principal était la mortalité perhospitalière. Les indicateurs secondaires incluaient les modifications de la gravité de l'état clinique, le nombre de jours sans oxygénothérapie et sans ventilation (à 28 jours), l'incidence d'un nouveau recours à l'oxygénothérapie et à la ventilation mécanique, la durée du séjour hospitalier et les taux d'effets indésirables. Nous avons effectué des analyses de sous-groupes préspécifiés selon la durée des symptômes avant le recrutement, l'âge, le sexe, et la gravité des symptômes à l'arrivée. RÉSULTATS: Parmi 52 hôpitaux canadiens, entre le 14 août 2020 et le 1er avril 2021, nous avons procédé à une attribution aléatoire de 1282 patients au remdésivir (n = 634) ou au traitement standard (n = 648). Parmi ces patients, 15 ont retiré leur consentement ou étaient encore hospitalisés, pour un échantillon total de 1267 patients. Parmi les patients auxquels on a attribué le remdésivir, la mortalité perhospitalière a été de 18,7 %, contre 22,6 % chez les patients sous traitement standard (risque relatif [RR] 0,83, intervalle de confiance [IC] de 95 % 0,67­1,03 et la mortalité à 60 jours a été de 24,8 % et 28,2 %, respectivement (IC de 95 % 0,72­1,07). Pour les patients non ventilés mécaniquement au départ; le recours à la ventilation mécanique a été de 8,0 % chez les patients qui recevaient le remdésivir et de 15,0 % chez ceux sous traitement standard (RR 0,53, IC de 95 % 0,38­0,75). Le nombre moyen de jours sans oxygénothérapie ni ventilation au jour 28 étaient de 15,9 (± écart-type [É.T.] 10,5) et 21,4 (± É.-T. 11,3) chez les patients sous remdésivir et de 14,2 (± É.-T. 11) et 19,5 (± É.-T. 12,3) chez les patients sous traitement standard (p = 0,006 et 0,007, respectivement). On n'a noté aucune différence quant à l'innocuité (p. ex., recours à la dialyse, changement du taux de créatinine, ou nouveaux cas d'insuffisance hépatique) entre les 2 groupes. INTERPRÉTATION: Comparativement au traitement standard, le remdésivir a eu un effet modeste, mais significatif sur certains indicateurs importants pour les patients et pour les systèmes de santé, tels que le recours à la ventilation mécanique. NUMÉRO D'ENREGISTREMENT DE LA RECHERCHE: ClinicalTrials.gov, no. NCT04330690.

Dual effects of NV-CoV-2 biomimetic polymer: An antiviral regimen against COVID-19.

Remdesivir (RDV) is the only antiviral drug approved for COVID-19 therapy by the FDA. Another drug LAGEVRIO™ (molnupiravir) though has not been approved yet by FDA but has been authorized on December 23, 2021, for emergency use to treat adults with mild-to moderate COVID-19 symptoms and for whom alternative COVID-19 treatment options are not clinically appropriate. The fact is that the efficacy of RDV is, however, limited in vivo though it is highly promising in vitro against SARS-CoV-2 virus. In this paper we are focusing on the action mechanism of RDV and how it can be improved in vivo. The stability of RDV alone and on encapsulation with our platform technology based polymer NV-387 (NV-CoV-2), were compared in presence of plasma in vitro and in vivo. Furthermore, a non-clinical pharmacology study of NV-CoV-2 (Polymer) and NV CoV-2 (Polymer encapsulated Remdesivir) in both NL-63 infected and uninfected rats was done. In addition, the antiviral activity of NV-CoV-2 and NV-CoV-2-R was compared with RDV in a cell culture study. The results are (i) NV-CoV-2 polymer encapsulation protects RDV from plasma-mediated catabolism in both in vitro and in vivo, studies; (ii) Body weight measurements of the normal (uninfected) rats after administration of the test materials (NV-CoV-2 and NV-CoV-2-R) showed no toxic effects. (iii) Body weight measurements and survival rates of the NL-63 infected rats were similar to the uninfected rats after treatment with NV-CoV-2 and NV-CoV-2-R. Overall, the efficacy as an antiviral regimens were found in this order as below; NV-CoV-2-R > NV-CoV-2 > RDV. Our platform technology based NV-387-encapsulated-RDV (NV-CoV-2-R) drug has a dual effect against different variants of the coronaviruses. First, NV-CoV-2 is an antiviral regimen. Secondly, RDV is protected from plasma-mediated degradation in transit. All together, NV-CoV-2-R is the safest and efficient regimen against COVID-19.

Remdesivir Plus Dexamethasone Versus Dexamethasone Alone for the Treatment of Coronavirus Disease 2019 (COVID-19) Patients Requiring Supplemental O2 Therapy: A Prospective Controlled Nonrandomized Study.

BACKGROUND: Remdesivir is an antiviral used to treat coronavirus disease 2019 (COVID-19), which improves some clinical outcomes. Dexamethasone has been shown to be effective in reducing mortality. It has been hypothesized that combination of these two drugs can improve mortality. We evaluated the effect of combination on mortality of COVID-19 patients requiring O2 therapy. METHODS: A prospective quasi-experimental study, including two independent, sequential controlled cohorts, one received remdesivir-dexamethasone and the other dexamethasone alone, was designed. All COVID-19 patients requiring supplemental O2 therapy were enrolled consecutively. The sample size to power mortality was a priori calculated. The primary endpoints were 30-day mortality and viral clearance differences. Secondary endpoints were differences in hospitalization times, improvement in respiratory failure (PO2/FiO2) and inflammatory indices (fibrinogen, CRP, neutrophil/lymphocyte ratio, D-Dimer). Kaplan-Meier curves and the log-rank test were used to evaluate significant differences in mortality between groups. RESULTS: In total, 151 COVID-19 patients were enrolled (remdesivir/dexamethasone group, 76, and dexamethasone alone, 75). No differences in demographic, clinical, and laboratory characteristics were observed between the 2 groups at baseline. Faster viral clearance occurred in the remdesivir/dexamethasone group compared to dexamethasone alone (median 6 vs 16 days; P < .001). The 30-day mortality in the remdesivir/dexamethasone group was 1.3%, whereas in dexamethasone alone was 16% (P < .005). In the remdesivir/dexamethasone group compared to dexamethasone alone there was a reduction in hospitalization days (P < .0001) and a faster improvement in both respiratory function and inflammatory markers. CONCLUSIONS: Remdesivir/dexamethasone treatment is associated with significant reduction in mortality, length of hospitalization, and faster SARS-CoV-2 clearance, compared to dexamethasone alone.

Patients with moderate to severe COVID-19 outcomes on remdesivir according to baseline 4C mortality score.

BACKGROUND: Remdesivir was the first antiviral to show clinical benefit in patients with moderate-to-severe COVID-19. Previous trials demonstrated a faster time to recovery in hospitalized patients treated with remdesivir vs placebo. Current guidelines recommend treatment with remdesivir based on hospitalization status, oxygen requirements, and time from symptom onset. However, other factors may be evaluated to determine disease severity and risk for progression. The 4C mortality score is a validated, eight variable score that may be used to categorize patients by mortality risk at the time of hospital admission for COVID pneumonia. The objective of this study was to determine if the 4C mortality score may be used to predict which patients with moderate to severe COVID-19 would benefit the most from remdesivir at the time of hospital admission. METHODS: This was a single-center retrospective cohort study comparing time to recovery among hospitalized patients with moderate-to-severe COVID-19 who were treated with remdesivir compared to those who were treated with standard of care (SOC). The primary outcome was time to recovery, defined as discharge from the hospital or no longer requiring supplemental oxygen, stratified by the 4C mortality score risk group. Secondary outcomes included in-hospital mortality, hospital length of stay, and time to recovery in patients who were started on remdesivir within 7 days from symptom onset vs after 7 days from symptom onset. A survival analysis was used to analyze time to recovery outcomes. RESULTS: Data was collected and analyzed for a total of 300 patients, of which 200 received remdesivir and 100 received SOC. Patients in the remdesivir group had a longer time to recovery compared to patients in the SOC group (6 days vs 4 days). This finding was driven by patients who were categorized to the intermediate risk and high risk mortality groups. Additionally, patients who received remdesivir had a longer length of hospital stay compared to those who received SOC (12 days vs 9 days). Remdesivir was not associated with an increased rate of adverse events. CONCLUSIONS: This study of patients admitted with moderate-to-severe COVID-19 found that patients who were treated with remdesivir had a longer time to recovery and a longer length of stay compared to those who received SOC. These findings add to the body of evidence questioning the benefit of remdesivir therapy among patients hospitalized with COVID-19.