Interaction and Antiviral Treatment of Coinfection between SARS-CoV-2 and Influenza in Vitro

BACKGROUND

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has lasted for three years. Coinfection with seasonal influenza may occur resulting in more severe diseases. The interaction between these two viruses for infection and the effect of antiviral treatment remains unclear.

METHODS

A SARS-CoV-2 and influenza H1N1 coinfection model on Calu-3 cell line was established, upon which the simultaneous and sequential coinfection was evaluated by comparing the viral load. The efficacy of molnupiravir and baloxavir against individual virus and coinfection were also studied.

RESULTS

The replication of SARS-CoV-2 was significantly interfered when the influenza virus was infected simultaneously or in advance (p<0.05). On the contrary, the replication of the influenza virus was not affected by the SARS-CoV-2. Molnupiravir monotherapy had significant inhibitory effect on SARS-CoV-2 when the concentration reached to 6.25μM but did not show any significant anti-influenza activity. Baloxavir was effective against influenza within the dosage range and showed significant effect of anti-SARS-CoV-2 at 16μM. In the treatment of coinfection, molnupiravir had significant effect for SARS-CoV-2 from 6.25μM to 100μM and inhibited H1N1 at 100μM (p<0.05). The tested dosage range of baloxavir can inhibit H1N1 significantly (p<0.05), while at the highest concentration of baloxavir did not further inhibit SARS-CoV-2, and the replication of SARS-CoV-2 significantly increased in lower concentrations. Combination treatment can effectively inhibit influenza H1N1 and SARS-CoV-2 replication during coinfection. Compared with molnupiravir or baloxavir monotherapy, combination therapy was more effective in less dosage to inhibit the replication of both viruses.

CONCLUSIONS

In coinfection, the replication of SARS-CoV-2 would be interfered by influenza H1N1. Compared with molnupiravir or baloxavir monotherapy, treatment with a combination of molnupiravir and baloxavir should be considered for early treatment in patients with SARS-CoV-2 and influenza coinfection.

Assessing antiviral treatment efficacy and risk factors for severe COVID-19 in kidney transplant recipients during the Omicron subvariant-dominant period: a retrospective study

BACKGROUND

Kidney transplant recipients (KTRs) are at risk of severe coronavirus disease 2019 (COVID-19), and even now that Omicron subvariants have become dominant, cases of severe disease are certain to occur. The aims of this retrospective study were to evaluate the efficacy of antiviral treatment for COVID-19 and to identify risk factors for severe disease in KTRs during Omicron subvariant-dominant periods.

METHODS

A total of 65 KTRs diagnosed with COVID-19 who received antiviral treatment between July 2022 and September 2023 were analyzed. Mild cases received oral molnupiravir (MP) as outpatient therapy, while moderate or worse cases received intravenous remdesivir (RDV) as inpatient therapy. In principle, mycophenolate mofetil was withdrawn and switched to everolimus. We investigated the efficacy of antiviral treatment and compared the clinical parameters of mild/moderate and severe/critical cases to identify risk factors for severe COVID-19.

RESULTS

Among 65 cases, 49 were mild, 6 were moderate, 9 were severe, and 1 was of critical severity. MP was administered to 57 cases; 49 (86%) improved and 8 (14%) progressed. RDV was administered to 16 cases; 14 (87%) improved and 2 (13%) progressed. Seventeen (26%) cases required hospitalization, and none died. Comparisons of the severe/critical group (n = 10) with the mild/moderate group (n = 55) demonstrated that the severe/critical group had a significantly higher median age (64 vs. 53 years, respectively; p = 0.0252), prevalence of diabetes (70% vs. 22%, respectively; p = 0.0047) and overweight/obesity (40% vs. 11%, respectively; p = 0.0393), as well as a significantly longer median time from symptom onset to initial antiviral therapy (3 days vs. 1 day, respectively; p = 0.0026). Multivariate analysis showed that a longer time from symptom onset to initial antiviral treatment was an independent risk factor for severe COVID-19 (p = 0.0196, odds ratio 1.625, 95% confidence interval 1.081-2.441).

CONCLUSION

These findings suggest that a longer time from symptom onset to initial antiviral treatment is associated with a higher risk of severe COVID-19 in KTRs. Initiating antiviral treatment as early as possible is crucial for preventing severe outcomes; this represents a valuable insight into COVID-19 management in KTRs.

Chimeric antigen receptor T-cell therapy after COVID-19 in refractory high-grade B-cell lymphoma

Although chimeric antigen receptor T-cell (CAR-T) therapies have dramatically improved the outcomes of relapsed/refractory B-cell malignancies, recipients suffer from severe humoral immunodeficiencies. Furthermore, patients with coronavirus disease 2019 (COVID-19) have a poor prognosis, as noted in several case reports of recipients who had COVID-19 before the infusion. We report the case of a 70-year-old woman who developed COVID-19 immediately before CAR-T therapy for high-grade B-cell lymphoma. She received Tixagevimab-Cilgavimab chemotherapy and radiation therapy but never achieved remission. She was transferred to our hospital for CAR-T therapy, but developed COVID-19. Her symptoms were mild and she was treated with long-term molnupiravir. On day 28 post-infection, lymphodepleting chemotherapy was restarted after a negative polymerase chain reaction (PCR) test was confirmed. The patient did not experience recurrence of COVID-19 symptoms or severe cytokine release syndrome. Based on the analysis and comparison of the previous reports with this case, we believe that CAR-T therapy should be postponed until a negative PCR test is confirmed. In addition, Tixagevimab-Cilgavimab and long term direct-acting antiviral agent treatment can be effective prophylaxis for severe COVID-19 and shortening the duration of infection.

Joint analysis of vaccination effectiveness and antiviral drug effectiveness for COVID-19: a causal inference approach

OBJECTIVES

This study aims to estimate the causal effects of oral antivirals and vaccinations in the prevention of all-cause mortality and progression to severe COVID-19 in an integrative setting with both antivirals and vaccinations considered as interventions.

METHODS

We identified hospitalized adult patients (i.e. aged 18 or above) in Hong Kong with confirmed SARS-CoV-2 infection between March 16, 2022, and December 31, 2022. An inverse probability-weighted (IPW) Andersen-Gill model with time-dependent predictors was used to address immortal time bias and produce causal estimates for the protection effects of oral antivirals and vaccinations against severe COVID-19.

RESULTS

Given prescription is made within 5 days of confirmed infection, nirmatrelvir-ritonavir is more effective in providing protection against all-cause mortality and development into severe COVID-19 than molnupiravir. There was no significant difference between CoronaVac and Comirnaty in the effectiveness of reducing all-cause mortality and progression to severe COVID-19.

CONCLUSIONS

The use of oral antivirals and vaccinations causes lower risks of all-cause mortality and progression to severe COVID-19 for hospitalized SARS-CoV-2 patients.

Molnupiravir for the treatment of COVID-19 outpatients: An updated meta-analysis

BACKGROUND

The majority of available data on molnupiravir come from an unvaccinated COVID-19 population. Therefore, we conducted this meta-analysis to integrate evidence from recent randomized controlled trials (RCTs) as well as observational studies stratified by vaccination status to determine the clinical efficacy and safety of molnupiravir in COVID-19 outpatients.

METHODS

We searched PubMed, Embase, the Cochrane Library, medRxiv, and ClinicalTrials.gov from inception to November 2023. We conducted our meta-analysis using RevMan 5.4 with risk ratio (RR) as the effect measure.

RESULTS

We included 8 RCTs and 5 observational studies in our meta-analysis. Molnupiravir reduced the risk of all-cause mortality (RR 0.28; 95% CI: 0.20-0.79, I2 = 0%) but did not decrease the hospitalization rate (RR 0.67; 95% CI: 0.45-1.00, I2 = 53%) in the overall population; in the immunized population, no benefits were observed. Molnupiravir lowered the rate of no recovery (RR 0.78; 95% CI: 0.76-0.81, I2 = 0%) and increased virological clearance at day 5 (RR 2.68; 95% CI: 1.94-4.22, I2 = 85%). There was no increase in the incidence of adverse events.

CONCLUSIONS

Molnupiravir does not decrease mortality and hospitalization rates in immunized patients with COVID-19. However, it does shorten the disease course and increases the recovery rate. The use of molnupiravir will need to be considered on a case-by-case basis in the context of the prevailing social circumstances, the resource setting, drug costs, and the healthcare burden.

Molnupiravir inhibits human norovirus and rotavirus replication in 3D human intestinal enteroids

Human norovirus (HuNoV) and human rotavirus (HRV) are the leading causes of gastrointestinal diarrhea. There are no approved antivirals and rotavirus vaccines are insufficient to cease HRV associated mortality. Furthermore, treatment of chronically infected immunocompromised patients is limited to off-label compassionate use of repurposed antivirals with limited efficacy, highlighting the urgent need of potent and specific antivirals for HuNoV and HRV. Recently, a major breakthrough in the in vitro cultivation of HuNoV and HRV derived from the use of human intestinal enteroids (HIEs). The replication of multiple circulating HuNoV and HRV genotypes can finally be studied and both in the same non-transformed and physiologically relevant model. Activity of previously described anti-norovirus or anti-rotavirus drugs, such as 2'-C-methylcytidine (2CMC), 7-deaza-2'-C-methyladenosine (7DMA), nitazoxanide, favipiravir and dasabuvir, was assessed against clinically relevant human genotypes using 3D-HIEs. 2CMC showed the best activity against HuNoV GII.4, while 7DMA was the most potent antiviral against HRV. We identified the anti-norovirus and -rotavirus activity of molnupiravir and its active metabolite, N4-hydroxycytidine (NHC), a broad-spectrum antiviral used to treat coronavirus disease 2019 (COVID-19). Molnupiravir and NHC inhibit HuNoV GII.4, HRV G1P[8], G2P[4] and G4P[6] in 3D-HIEs with high selectivity and show a potency comparable to 2CMC against HuNoV. Moreover, molnupiravir and NHC block HRV viroplasm formation, but do not alter its size or subcellular localization. Taken together, molnupiravir inhibits both HuNoV and HRV replication, suggesting that the drug could be a candidate for the treatment of patients chronically infected with either one of these diarrhea causing viruses.

Virology and safety profile of Molnupiravir at three different doses for treatment of SARS-CoV-2: a systematic review and meta-analysis

Molnupiravir is incorporated into the viral genome, thereby increasing errors, mismatching, and misdirecting the viral polymerase thereby, halting viral RNA replication of SARS-CoV-2. Following PRISMA guidelines, a thorough literature search was performed on electronic and medical databases from December 2022 till January 2023. Molnupiravir 800 mg showed significance in creating viral RNA error rate at Day 5 (WMD: 4.91; 95% CI; [1.19, 8.63] p = 0.01; I2  = 0%). Similarly, at 400 mg, Molnupiravir creates an RNA error rate (WMD: 2.27; 95% CI; 2.27 [0.50, 4.65] p = 0.02; I2  = 0%). Furthermore, exhibit a significant outcome for mean change in SARS-CoV-2 RNA viral load from baseline in nasopharyngeal sample at 800 mg Molnupiravir on Day 3 (WMD: -0.22; 95% CI; [-0.35, -0.08] p = 0.002; I2  = 0%), Day 5 (WMD: -0.32; 95% CI; [-0.53, -0.11] p = 0.003; I2  = 24%) and overall pooled analysis (WMD: -0.17; 95% CI; [-0.29, 0.33] p = 0.003; I2  = 32%). Moreover, Molnupiravir 400 mg significantly reduced the incidence of death compared to the placebo group (RR: 0.17; 95% CI; [0.07, 0.43] p = 0.0002; I2  = 0%). Molnupiravir effectively treats SARS-CoV-2 patients by eliminating the virus from the host.

The effect of molnupiravir and nirmatrelvir on SARS-CoV-2 genome diversity in infected and immune suppressed mice

Objectives

Immunocompromised individuals are susceptible to severe COVID-19 and potentially contribute to the emergence of variants with altered pathogenicity due to persistent infection. This study investigated the impact of immunosuppression on SARS-CoV-2 infection in k18-hACE2 mice and the effectiveness of antiviral treatments in this context.

Methods

Mice were immunosuppressed using cyclophosphamide and infected with a B lineage of SARS-CoV-2. Molnupiravir and nirmatrelvir, alone and in combination, were administered and viral load and viral sequence diversity was assessed.

Results

Treatment of infected but immune compromised mice with both compounds either singly or in combination resulted in decreased viral loads and pathological changes compared to untreated animals. Treatment also abrogated infection of neuronal tissue. However, no consistent changes in the viral consensus sequence were observed, except for the emergence of the S:H655Y mutation. Molnupiravir, but not nirmatrelvir or immunosuppression alone, increased the transition/transversion (Ts/Tv) ratio, representative of A>G and C>U mutations and this increase was not altered by the co-administration of nirmatrelvir with molnupiravir.Notably, immunosuppression itself did not appear to promote the emergence of mutational characteristic of variants of concern (VOCs).

Conclusions

Further investigations are warranted to fully understand the role of immunocompromised individuals in VOC development and to inform optimised public health strategies. It is more likely that immunodeficiency promotes viral persistence but does not necessarily lead to substantial consensus-level changes in the absence of antiviral selection pressure. Consistent with mechanisms of action, molnupiravir showed a stronger mutagenic effect than nirmatrelvir in this model.

Determining and Comparing the Real-World Effectiveness of Molnupiravir and Nirmatrelvir-Ritonavir in Patients Hospitalized With COVID-19

BACKGROUND

Current guidelines recommend using nirmatrelvir-ritonavir for coronavirus disease 2019 (COVID-19) treatment, but its potential drug interactions and contraindications limit its applicability in certain categories of patients. The aim of the study was to evaluate the real-world effectiveness of molnupiravir and nirmatrelvir-ritonavir in managing COVID-19 among hospitalized patients.

METHODS

We conducted a retrospective cohort study among hospitalized COVID-19 patients who received molnupiravir or nirmatrelvir-ritonavir and did not require baseline supplemental oxygen from February 2022 to January 2023. We compared the effectiveness of molnupiravir and nirmatrelvir-ritonavir with a focus on disease progression.

RESULTS

The study included 401 high-risk, hospitalized adult COVID-19 patients who received molnupiravir or nirmatrelvir-ritonavir. No significant difference was found in disease progression, the composite outcome of disease progression (4.0% vs. 1.4%, P = 0.782), and O2 supplementation via nasal prong (21.8% vs. 14.8%, P = 0.115) between the patients treated with molnupiravir and those treated with nirmatrelvir-ritonavir. This finding was similar after 1:1 propensity-score matching. In the multivariate analysis, molnupiravir treatment was not significantly associated with progression to severe disease.

CONCLUSION

In conclusion, our findings suggest that similar to nirmatrelvir-ritonavir, molnupiravir has a distinct potential role in COVID-19 treatment, transcending its current perceived status as only a secondary option.

Comparison of azvudine, molnupiravir, and nirmatrelvir/ritonavir in adult patients with mild-to-moderate COVID-19: a retrospective cohort study

This study aimed to explore the effectiveness and safety of azvudine, nirmatrelvir/ritonavir, and molnupiravir in adult patients with mild-to-moderate COVID-19. This retrospective cohort study included patients with mild-to-moderate COVID-19 (asymptomatic, mild, and common types) at the First Hospital of Changsha (Hunan Province, China) between March and November 2022. Eligible patients were classified into the azvudine, nirmatrelvir/ritonavir, or molnupiravir groups according to the antiviral agents they received. The outcomes were the times to nucleic acid negative conversion (NANC). This study included 157 patients treated with azvudine (n = 66), molnupiravir (n = 66), or nirmatrelvir/ritonavir (n = 25). There were no statistically significant differences in the time from diagnosis to NANC among the azvudine, molnupiravir, and nirmatrelvir/ritonavir groups [median, 9 (95% CI 9-11) vs. 11 (95% CI 10-12) vs. 9 (95% CI 8-12) days, P = 0.15], time from administration to NANC [median, 9 (95% CI 8-10) vs. 10 (95% CI 9.48-11) vs. 8.708 (95% CI 7.51-11) days, P = 0.50], or hospital stay [median, 11 (95% CI 11-13) vs. 13 (95% CI 12-14) vs. 12 (95% CI 10-14) days, P = 0.14], even after adjustment for sex, age, COVID-19 type, comorbidities, Ct level, time from diagnosis to antiviral treatment, and number of symptoms. The cumulative NANC rates in the azvudine, molnupiravir, and nirmatrelvir/ritonavir groups were 15.2%/12.3%/16.0% at day 5 (P = 0.858), 34.8%/21.5%/32.0% at day 7 (P = 0.226), 66.7%/52.3%/60.0% at 10 days (P = 0.246), and 86.4%/86.2%/80.0% at day 14 (P = 0.721). No serious adverse events were reported. Azvudine may be comparable to nirmatrelvir/ritonavir and molnupiravir in adult patients with mild-to-moderate COVID-19 regarding time to NANC, hospital stay, and AEs.

Enhancement efficiency delivery of antiviral Molnupiravir-drug via the loading with self-assembly nanoparticles of pycnogenol and cellulose which are decorated by zinc oxide nanoparticles for COVID-19 therapy

The target of the study is to modify the efficiency of Molnupiravir-drug (MOL) for COVID-19 therapy via the rearrangement of the building engineering of MOL-drug by loading it with self-assembly biomolecules nanoparticles (NPs) of pycnogenol (Pyc) and cellulose (CNC) which are decorated by zinc oxide nanoparticles. The synthesis and characterization of the modified drug are performing successfully, the loading and release process of the MOL drug on a nano surface is measured by UV-Vis spectroscopy under room temperature and different pH. The release efficiency of the MOL drug is calculated to be 65% (pH 6.8) and 69% (pH 7.4). The modified MOL drug displays 71% (pH 6.8) and 78% (pH 7.4) for CNC@Pyc.MOL nanocomposite, while CNC@Pyc.MOL.ZnO nanocomposite gave values at 76% (pH 6.8) and 78% (pH 7.4), the efficiency recorded after 19 h. The biological activity of the MOL-drug and modified MOL-drug is measured, and the cytotoxicity is performed by SRB technique, where the self-assembly (CNC@Pyc) appears to be a safe healthy, and high viability against the examined cell line. The antioxidant activity and anti-inflammatory are evaluated, where the nanocomposite that has ZnO NPs (CNC@Pyc.MOL.ZnO) gave high efficiency compared to the composite without ZnO NPs. The CPE-inhibition assay is used to identify potential antivirals against CVID-19 (229E virus), the viral inhibition (%) was reported at 37.6 % (for 800 µg/ml) and 18.02 % (for 400 µg/ml) of CNC@Pyc.MOL.ZnO. So, the modified MOL-drug was suggested as a replacement drug for the therapy of COVID-19 compared to MOL-drug, but the results need clinical trials.

Antiviral therapy of coronavirus disease 2019 (COVID-19)

The coronavirus disease 2019 (COVID-19) pandemic has reached a turning point. The non-pharmaceutical interventions for preventing COVID-19 are lifting. Vaccination uptake is increasing in general, but this strategy is continuously challenged by the rapid evolution of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Of note, the Omicron subvariants spread globally for at least one year, and the most recently developed subvariants show strong immune evasion to preexisting immunity, either from previous infection, vaccination or both. Therefore, early and appropriate antiviral agents to treat patients at risk for severe COVID-19 or death is crucial to decrease morbidities and mortalities, to restore the healthcare capacities and to facilitate a return to the new normal. Current antiviral therapy for COVID-19 consist of neutralizing monoclonal antibodies (mAbs) and direct antiviral agents. Each agent has been proved for early ambulatory treatment of COIVD-19, but suffer from variable effectiveness and limitations due to patients' comorbidities, drug properties, or antiviral resistance. Besides, some specific mAbs are indicated for prophylaxis of COVID-19 before or after close contact with confirmed COVID-19 patients. This review article summarizes the evidence and unmet needs of the currently available antiviral agents for management of COVID-19 in the context of the Omicron subvariants.

Effect of pre-hospitalization use of oral antiviral agents on reducing critical illness and mortality for patients with COVID-19 pneumonia

OBJECTIVES

This study aimed to evaluate the effect of administering nirmatrelvir/ritonavir and molnupiravir before hospitalisation on subsequent critical illness among patients with COVID-19 pneumonia.

METHODS

This retrospective cohort study included patients with COVID-19 pneumonia who required hospitalisation between 1 January 1 2022 and 31 August 2022. The primary outcomes were the development of critical illness, including intensive care unit admission, use of mechanical ventilation, or mortality. A multivariate logistic regression analysis was conducted to assess the varying risks of critical illness and mortality. A total of 1,011 COVID-19 patients were analysed. Among them, 304 (30.1%) received molnupiravir and 131 (13.0%) received nirmatrelvir/ritonavir before hospitalisation.

RESULTS

There were significant reductions for critical illness (adjusted odds ratio 0.29, 95% confidence interval 0.21-0.39, P < 0.001) and mortality (adjusted odds ratio 0.40, 95% confidence interval 0.27-0.59, P < 0.001) in patients receiving oral antivirals compared with those who did not. No significant differences in critical illness were observed between molnupiravir and nirmatrelvir/ritonavir. The combination of COVID-19 vaccines and oral antivirals can further reduce the risk of critical illness in high-risk populations.

CONCLUSION

Administering molnupiravir and nirmatrelvir/ritonavir before hospitalisation reduced the risk of COVID-19 patients with moderate to severe pneumonia progressing to critical illness and mortality.

Safety and Effectiveness of Molnupiravir in Japanese Patients with COVID-19: Final Report of Post-marketing Surveillance in Japan

INTRODUCTION

Molnupiravir is an orally available prodrug of N-hydroxycytidine that received special approval for emergency treatment of coronavirus disease 2019 (COVID-19) in Japan in December 2021 and full approval in April 2023. To assess the real-world safety and effectiveness of molnupiravir in Japanese patients with COVID-19, we conducted nationwide post-marketing surveillance to collect data at registered institutions in Japan.

METHODS

The surveillance data were collected from December 27, 2021, to May 2, 2023. All reported adverse events were collected for safety analysis. Adverse drug reactions (ADRs) were assessed by the treating physicians. Effectiveness was assessed by the composite of hospitalization or all-cause death in outpatients and the composite of oxygen/mechanical ventilation initiation or all-cause death in inpatients. The observation period was from molnupiravir initiation through day 29.

RESULTS

Of 3214 patients enrolled in the survey, 3179 were analyzed for safety. At baseline, 52.31% (1663/3179) of patients were male, the median (range) age was 69.0 (18-107) years, 82.38% (2619/3179) received COVID-19 vaccines, and 95.72% (3043/3179) had risk factors for severe COVID-19 illness. COVID-19 severity at baseline was mild in 86.44% (2748/3179) and moderate I in 10.22% (325/3179). A total of 205 ADRs occurred in 5.50% (175/3179) of patients; ADRs that occurred in > 0.5% of patients were diarrhea (1.86% [59/3179]) and rash (0.69% [22/3179]). Seven serious ADRs were reported in seven patients. In the effectiveness analysis population, the incidence of all-cause death through day 29 was 1.14% (34/2988), and the incidence of death through day 29 related to COVID-19 was 0.40% (12/2988). The cumulative incidence of the composite endpoint was 2.34% (47/2006) in outpatients and 4.60% (38/826) in inpatients.

CONCLUSIONS

This large-scale survey showed that molnupiravir was safe and effective in real-world settings in highly vaccinated Japanese patients with COVID-19, including older patients and those with comorbidities.

Design and study of bioisosteric analogues of the drug Molnupiravir as potential therapeutics against SARS-COV-2: an in silico approach

The ongoing SARS-CoV-2 pandemic has created an urgent need for effective antiviral drugs that can be rapidly developed and utilized to treat patients infected with the virus. Molnupiravir, a direct-acting oral antiviral, has shown promising results in reducing viral infections with SARS-CoV-2. Nonetheless, there is still a need for the development of more efficacious analogues with enhanced interaction with the specific target, the RNA dependent RNA polymerase (RdRp) and better physico-chemical profile. Our study is based on a rational design strategy, known as "bioisosterism", to design some analogues. The pool of bioisosteric structural analogues was further enriched using the "SwissBioisostere" database. Only structures with a Tanimoto score more than 0.85 (calculated using the Maximum Common Substructure scoring method) and with ΔlogP (lipophilicity) ± 1 and ΔPSA (Polar Surface Area) ± 10 Å were retained. Next, molecular docking studies were conducted using AutoDock Vina®. Ligand and receptor preparation and molecular interaction analysis were performed using UCSF Chimera® and Biovia Discovery Studio®, respectively. The three-dimensional structure of the RdRp of SARS-CoV-2 (6M71) was sourced from RCSB PDB®. Ligands were prepared in 3D, and the receptor underwent solvent removal, elimination of alternative positions, hydrogen atom addition, and partial charge assignment. Binding pocket coordinates were determined, and utilized for AutoDock Vina® docking. Parallelly, the druglikeness of our molecules was predicted using the website ADME-SWISS: http://www.swissadme.ch/, based on Lipinski and Weber scores. Docking outcomes, combined to druglikeness prediction results, identified two fluorinated analogues with superior binding affinity (lowest score and an RMSD ≤ 2 Å) and improved physico-chemical properties (no violation of Lipinsky and Veber rules). This study contributes to the development of more effective antiviral drugs by providing insights into potential uegs with enhanced interactions with RNA polymerase and better druglikeness profile.

Graphical abstract

Virologic Outcomes with Molnupiravir in Non-hospitalized Adult Patients with COVID-19 from the Randomized, Placebo-Controlled MOVe-OUT Trial

INTRODUCTION

The randomized, placebo-controlled, double-blind MOVe-OUT trial demonstrated molnupiravir (800 mg every 12 h for 5 days) as safe and effective for outpatient treatment of mild-to-moderate COVID-19, significantly reducing the risk of hospitalization/death in high-risk adults. At the time of that report, virologic assessments from the trial were partially incomplete as a result of their time-intensive nature. Here we present final results from all prespecified virology endpoints in MOVe-OUT based on the full trial dataset.

METHODS

Nasopharyngeal swabs were collected at baseline (day 1, prior to first dose) and days 3, 5 (end-of-treatment visit), 10, 15, and 29. From these samples, change from baseline in SARS-CoV-2 RNA titers (determined by quantitative PCR), detection of infectious SARS-CoV-2 (by plaque assay), and SARS-CoV-2 viral error induction (determined by whole genome next-generation sequencing) were assessed as exploratory endpoints.

RESULTS

Molnupiravir was associated with greater mean reductions from baseline in SARS-CoV-2 RNA than placebo (including 50% relative reduction at end-of-treatment) through day 10. Among participants with infectious virus detected at baseline (n = 96 molnupiravir, n = 97 placebo) and evaluable post-baseline samples, no molnupiravir-treated participant had infectious SARS-CoV-2 by day 3, whereas infectious virus was recovered from 21% of placebo-arm participants on day 3 and 2% at end-of-treatment. Consistent with molnupiravir's mechanism of action, sequence analysis demonstrated that molnupiravir was associated with an increased number of low-frequency transition errors randomly distributed across the SARS-CoV-2 RNA genome compared with placebo (median 143.5 molnupiravir, 15 placebo), while transversion errors were infrequent overall (median 2 in both arms). Outcomes were consistent regardless of baseline SARS-CoV-2 clade, presence of SARS-CoV-2-specific immune response, or viral load.

CONCLUSIONS

A 5-day course of orally administered molnupiravir demonstrated a consistently greater virologic effect than placebo, including rapidly eliminating infectious SARS-CoV-2, in high-risk outpatients with mild-to-moderate COVID-19.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT04575597.

Effectiveness of Molnupiravir Treatment in Patients with COVID-19 in Korea: A Propensity Score Matched Study

BACKGROUND

The MOVe-OUT (efficacy and safety of molnupiravir [MK-4482] in non-hospitalized adult participants with COVID-19 [MK-4482-002]) trial reported that the administration of molnupiravir in unvaccinated patients with coronavirus disease 2019 (COVID-19) before the Omicron epidemic showed a preventive effect of 31% against hospitalization and death. However, studies on the preventive effect of molnupiravir against progression to severe disease and death in patients with COVID-19 during the Omicron epidemic are limited. This study aimed to evaluate the preventive effect of molnupiravir against severe/critical illness or death and death in Korean patients with COVID-19 who were vaccinated mostly during the Omicron epidemic.

MATERIALS AND METHODS

This study used large-scale retrospective cohort data to select patients with COVID-19 who were either treated or not treated with molnupiravir, between August 2022 and March 2023, at a ratio of 1 : 4 using the propensity score matching method. In total, 762,768 patients comprised the non- administered group, and 190,692 patients comprised the molnupiravir-administered group. The preventive effect of molnupiravir against severe/critical illness or death and death was analyzed using logistic regression analysis.

RESULTS

The preventive effect of molnupiravir against severe/critical illness or death and death, represented by the odds ratio (OR) and 95% confidence interval (CI), in the molnupiravir-administered and non-administered group was (OR: 0.714; CI: 0.667 - 0.764) and (OR: 0.749; CI: 0.682 - 0.823), respectively. As age increased, the preventive effect against severe/critical illness or death and death increased. The preventive effect against severe/critical illness or death at ≥60 years was (OR: 0.669; CI: 0.624 - 0.717), at ≥70 years was (OR: 0.614; CI: 0.570 - 0.661), and at ≥80 years was (OR: 0.563; CI: 0.515 - 0.615). The preventive effect against death at ≥60 years was (OR: 0.729; CI: 0.663 - 0.802), at ≥70 years was (OR: 0.676; CI: 0.612 - 0.747), and at ≥80 years was (OR: 0.622; CI: 0.554 - 0.698).

CONCLUSION

Although molnupiravir showed a relatively weak preventive effect against severe/critical illness or death (29%) and death (25%) among patients with COVID-19, it exhibited a stronger protective effect in older patients than in younger patients. In particular, the preventive effect against severe/critical illness or death (44%) and death (38%) in those aged ≥80 years was pronounced. This study strongly suggests that molnupiravir administration can alleviate the burden on the medical system, and treat patients with COVID-19 effectively by reducing its progression to severe disease and death.

A sensitive UPLC-MS/MS method for the simultaneous assay and trace level genotoxic impurities quantification of SARS-CoV-2 inhibitor-Molnupiravir in its pure and formulation dosage forms using fractional factorial design

Two potential genotoxic impurities were identified (PGTIs)-viz. 4-amino-1-((2R,3R,4S,5R)-3,4-dihydroxy-5-(hydroxymethyl)tetrahydrofuran-2-yl)pyrimidin-2(1H)-one (PGTI-1), and 1-(2R,3R,4S,5R)-3,4-dihydroxy-5-(hydroxymethyl)tetrahydrofuran-2-yl)pyrimidin-2,4(1H,3H)-one (PGTI-II) in the Molnupiravir (MOPR) synthetic routes. COVID-19 disease was treated with MOPR when mild to moderate symptoms occurred. Two (Q)-SAR methods were used to assess the genotoxicity, and projected results were positive and categorized into Class-3 for both PGTIs. A simple, accurate and highly sensitive ultra-performance liquid chromatography-mass spectrometry (UPLC-MS/MS) method was optimized for the simultaneous quantification of the assay, and these impurities in MOPR drug substance and formulation dosage form. The multiple reaction monitoring (MRM) technique was utilized for the quantification. Prior to the validation study, the UPLC-MS method conditions were optimised using fractional factorial design (FrFD). The optimized Critical Method Parameters (CMPs) include the percentage of Acetonitrile in MP B, Concentration of Formic acid in MP A, Cone Voltage, Capillary Voltage, Collision gas flow and Desolvation temperature were determined from the numerical optimization to be 12.50 %, 0.13 %, 13.6 V, 2.6 kV, 850 L/hr and 375 °C, respectively. The optimized chromatographic separation achieved on Waters Acquity HSS T3 C18 column (100 mm × 2.1 mm, 1.8 µm) in a gradient elution mode with 0.13% formic acid in water and acetonitrile as mobile phases, column temperature kept at 35 °C and flow rate at 0.5 mL/min. The method was successfully validated as per ICH guidelines, and demonstrated excellent linearity over the concentration range of 0.5-10 ppm for both PGTIs. The Pearson correlation coefficient of each impurity and MOPR was found to be higher than 0.999, and the recoveries were in between the range of 94.62 to 104.05% for both PGTIs and 99.10 to 100.25% for MOPR. It is also feasible to utilise this rapid method to quantify MOPR accurately in biological samples.

Effectiveness and Adverse Events of Nirmatrelvir/Ritonavir Versus Molnupiravir for COVID-19 in Outpatient Setting: Multicenter Prospective Observational Study

BACKGROUND

In this study, we aimed to compare the effectiveness and adverse reactions of nirmatrelvir/ritonavir and molnupiravir in high-risk outpatients with coronavirus disease 2019 (COVID-19).

METHODS

This multicenter prospective observational study evaluated the rate of hospitalization, death, and adverse events within 28 days of oral antiviral agent prescription (molnupiravir, n = 240; nirmatrelvir/ritonavir, n = 240) to 480 nonhospitalized adult patients with COVID-19 from August 2, 2022 to March 31, 2023.

RESULTS

Patients receiving molnupiravir had a higher prevalence of comorbidities (85.8% vs. 70.4%; P < 0.001) and a higher Charlson comorbidity index (2.8 ± 1.4 vs. 2.5 ± 1.5; P = 0.009) than those receiving nirmatrelvir/ritonavir. Three patients required hospitalization (nirmatrelvir/ritonavir group, n = 1 [0.4%]; molnupiravir group, n = 2 [0.8%]; P = 1.000). Nirmatrelvir/ritonavir was associated with a higher risk of adverse events than molnupiravir (odds ratio [OR], 1.96; 95% confidence interval [CI], 1.27-3.03), especially for patients aged 65 years and older (OR, 3.04; 95% CI, 1.71-5.39). The severity of adverse events in both groups was mild to moderate and improved after discontinuation of medication. In the molnupiravir group, age ≥ 65 years (OR, 0.43 95% CI, 0.22-0.86) and appropriate vaccination (OR, 0.37; 95% CI, 0.15-0.91) reduced the occurrence of adverse events.

CONCLUSION

The rates of hospitalization and death were low and not significantly different between high-risk patients who received either nirmatrelvir/ritonavir or molnupiravir. Although adverse events were more frequent with nirmatrelvir/ritonavir than with molnupiravir, none were severe. Nirmatrelvir/ritonavir can be safely used to treat COVID-19, while molnupiravir could be considered as an alternative treatment option for high-risk groups.

Comparative docking and molecular dynamics studies of molnupiravir (EIDD-2801): implications for novel mechanisms of action on influenza and SARS-CoV-2 protein targets

Molnupiravir (EIDD-2801) (MLN) is an oral antiviral drug for COVID-19 treatment, being integrated into viral RNA through RNA-dependent RNA polymerase (RdRp). Upon ingestion, MLN is transformed into two active metabolites: β-d-N4-hydroxycytidine (NHC) (EIDD-1931) in the host plasma, and EIDD-1931-triphosphate (MTP) within the host cells. However, recent studies provide increasing evidence of MLN's interactions with off-target proteins beyond the viral genome, suggesting that the complete mechanisms of action of MLN remain unclear. The aim of this study was therefore to investigate the molecular interactions of MLN in the form of NHC and MTP with the non-RNA structural components of avian influenza (hemagglutinin, neuraminidase) and SARS-CoV-2 (spike glycoprotein, Mpro, and RdRp) viruses and to elucidate whether these two metabolites possess the ability to form stable complexes with these major viral components. Molecular docking of NHC and MTP was performed using AutoDock 4.2.6 and the obtained protein-drug complexes were submitted to 200-ns molecular dynamics simulations in triplicate with subsequent free energy calculations using GROMACS. Docking scores, molecular dynamics and MM/GBSA results showed that MTP was tightly bound within the active site of SARS-CoV-2 RdRp and remained highly stable throughout the 200-ns simulations. Besides, it was also shown that NHC and MTP formed moderately-to-highly stable molecular complexes with off-target receptors hemagglutinin, neuraminidase and Mpro, but rather weak interactions with spike glycoprotein. Our computational findings suggest that NHC and MTP may directly inhibit these receptors, and propose that additional studies on the off-target effects of MLN, i.e. real-time protein binding assays, should be performed.Communicated by Ramaswamy H. Sarma.

Favipiravir and Ribavirin protect immunocompetent mice from lethal CCHFV infection

Crimean-Congo hemorrhagic fever virus (CCHFV) causes Crimean-Congo hemorrhagic fever (CCHF) in humans with high morbidity and mortality. Currently, there is neither an approved antiviral drug nor a vaccine against CCHFV. In this study, we describe a lethal model of CCHFV infection using a mouse-adapted strain of CCHFV (MA-CCHFV) in adult wild-type male mice. Infected mice developed high viral loads, tissue pathology, and inflammatory immune responses before ultimately succumbing to the infection. We used the model to evaluate the protective efficacy of nucleoside analogs monulpiravir, favipiravir, ribavirin, the antibiotic tigecycline and the corticosteroids dexamethasone and methylprednisolone against lethal CCHFV infection. Tigecycline, monulpiravir and the corticosteroids failed to protect mice from lethal MA-CCHFV infection. In contrast, favipiravir and ribavirin protected animals from clinical disease and death even when treatment was delayed. Despite demonstrating uniform protection, CCHFV RNA persisted in survivors treated with favipiravir and ribavirin. Nevertheless, the study demonstrated the anti-CCHFV efficacy of favipiravir and ribavirin in a model with intact innate immunity and establishes this model for continued development of CCHFV countermeasures.

A matched-paired analysis from the EPICOVIDEHA registry

INTRODUCTION

Molnupiravir and nirmatrelvir/ritonavir are antivirals used to prevent progression to severe SARS-CoV-2 infections and decrease hospitalisation and mortality rates. Nirmatrelvir/ritonavir was authorised in Europe in December 2021, whereas molnupiravir is not yet licensed in Europe as of February 2022. Molnupiravir may be an alternative to nirmatrelvir/ritonavir because it is associated with fewer drug-drug interactions and contraindications. A caveat for molnupiravir is the mode of action induces viral mutations. Mortality rate reduction with molnupiravir was less pronounced than that with nirmatrelvir/ritonavir in patients without haematological malignancy. Little is known about the comparative efficacy of the two drugs in patients with haematological malignancy at high-risk of severe COVID-19. Thus, molnupiravir and nirmatrelvir/ritonavir were compared in a cohort of patients with haematological malignancies.

METHODS

Clinical data from patients treated with molnupiravir or nirmatrelvir/ritonavir monotherapy for COVID-19 were retrieved from the EPICOVIDEHA registry. Patients treated with molnupiravir were matched by sex, age (±10 years), and severity of baseline haematological malignancy to controls treated with nirmatrelvir/ritonavir.

RESULTS

A total of 116 patients receiving molnupiravir for the clinical management of COVID-19 were matched to an equal number of controls receiving nirmatrelvir/ritonavir. In each of the groups, 68 (59%) patients were male; with a median age of 64 years (interquartile range [IQR] 53-74) for molnupiravir recipients and 64 years (IQR 54-73) for nirmatrelvir/ritonavir recipients; 56.9% (n=66) of the patients had controlled baseline haematological malignancy, 12.9% (n=15) had stable disease, and 30.2% (n=35) had active disease at COVID-19 onset in each group. During COVID-19 infection, one third of patients from each group were admitted to hospital. Although a similar proportion of patients in the two groups were vaccinated (molnupiravir n=77, 66% vs. nirmatrelvir/ritonavir n=87, 75%), more of those treated with nirmatrelvir/ritonavir had received four vaccine doses (n=27, 23%) compared with those treated with molnupiravir (n=5, 4%) (P<0.001). No differences were detected in COVID-19 severity (P=0.39) or hospitalisation (P=1.0). No statistically significant differences were identified in overall mortality rate (P=0.78) or survival probability (d30 P=0.19, d60 P=0.67, d90 P=0.68, last day of follow up P=0.68). Deaths were either attributed to COVID-19, or the infection was judged by the treating physician to have contributed to death.

CONCLUSIONS

Hospitalisation and mortality rates with molnupiravir were comparable to those with nirmatrelvir/ritonavir in high-risk patients with haematological malignancies and COVID-19. Molnupiravir is a plausible alternative to nirmatrelvir/ritonavir for COVID-19 treatment in patients with haematological malignancy.

Effectiveness of molnupiravir vs nirmatrelvir-ritonavir in non-hospitalised and hospitalised patients with COVID-19: a target trial emulation study

Background

Molnupiravir and nirmatrelvir-ritonavir have emerged as promising options for COVID-19 treatment, but direct comparisons of their effectiveness have been limited. This study aimed to compare the effectiveness of these two oral antiviral drugs in non-hospitalised and hospitalised patients with COVID-19.

Methods

In this target trial emulation study, we used data from a territory-wide electronic health records database on eligible patients aged ≥18 years infected with COVID-19 who were prescribed either molnupiravir or nirmatrelvir-ritonavir within five days of infection between 16 March 2022 and 31 December 2022 in the non-hospitalised and hospitalised settings in Hong Kong. A sequence trial approach and 1:1 propensity score matching was applied based on age, sex, number of COVID-19 vaccine doses received, Charlson comorbidity index, comorbidities, and drug use within past 90 days. Cox regression adjusted with patients' characteristics was used to compare the risk of effectiveness outcomes (all-cause mortality, intensive care unit (ICU) admission or ventilatory support and hospitalisation) between groups. Subgroup analyses included age (<70; ≥70 years); sex, Charlson comorbidity index (<4; ≥4), and number of COVID-19 vaccine doses received (0-1; ≥2 doses).

Findings

A total of 63,522 non-hospitalised (nirmatrelvir-ritonavir: 31,761; molnupiravir: 31,761) and 11,784 hospitalised (nirmatrelvir-ritonavir: 5892; molnupiravir: 5892) patients were included. In non-hospitalised setting, 336 events of all-cause mortality (nirmatrelvir-ritonavir: 71, 0.22%; molnupiravir: 265, 0.83%), 162 events of ICU admission or ventilatory support (nirmatrelvir-ritonavir: 71, 0.22%; molnupiravir: 91, 0.29%), and 4890 events of hospitalisation (nirmatrelvir-ritonavir: 1853, 5.83%; molnupiravir: 3037, 9.56%) were observed. Lower risks of all-cause mortality (absolute risk reduction (ARR) at 28 days: 0.61%, 95% CI: 0.50-0.72; HR: 0.43, 95% CI: 0.33-0.56) and hospital admission (ARR at 28 days: 3.73%, 95% CI: 3.31-4.14; HR: 0.72, 95% CI: 0.67-0.76) were observed in nirmatrelvir-ritonavir users compared to molnupiravir users. In hospitalised setting, 509 events of all-cause mortality (nirmatrelvir-ritonavir: 176, 2.99%; molnupiravir: 333, 5.65%), and 50 events of ICU admission or ventilatory support (nirmatrelvir-ritonavir: 26, 0.44%; molnupiravir: 24, 0.41%) were observed. Risk of all-cause mortality was lower for nirmatrelvir-ritonavir users than for molnupiravir users (ARR at 28 days: 2.66%, 95% CI: 1.93-3.40; HR: 0.59, 95% CI: 0.49-0.71). In both settings, there was no difference in the risk of intensive care unit admission or ventilatory support between groups. The findings were consistent across all subgroup's analyses.

Interpretation

Our analyses suggest that nirmatrelvir-ritonavir was more effective than molnupiravir in reducing the risk of all-cause mortality in both non-hospitalised and hospitalised patients. When neither drug is contraindicated, nirmatrelvir-ritonavir may be considered the more effective option.

Funding

HMRF Research on COVID-19, The Hong Kong Special Administrative Region (HKSAR) Government; Collaborative Research Fund, University Grants Committee, the HKSAR Government; and Research Grant from the Food and Health Bureau, the HKSAR Government; the Laboratory of Data Discovery for Health (D24H) funded by the AIR@InnoHK administered by Innovation and Technology Commission.

An active metabolite of the anti-COVID-19 drug molnupiravir impairs mouse preimplantation embryos at clinically relevant concentrations

Molnupiravir is a nucleoside analog antiviral that is authorized for use in the treatment of COVID-19. For its therapeutic action, molnupiravir is converted after ingestion to the active metabolite N4-hydroxycytidine, which is incorporated into the viral genome to cause lethal mutagenesis. Molnupiravir is not recommended for use during pregnancy, because preclinical animal studies suggest that it is hazardous to developing embryos. However, the mechanisms underlying the embryotoxicity of molnupiravir are currently unknown. To gain mechanistic insights into its embryotoxic action, the effects of molnupiravir and N4-hydroxycytidine were examined on the in vitro development of mouse preimplantation embryos. Molnupiravir did not prevent blastocyst formation even at concentrations that were much higher than the therapeutic plasma levels. By contrast, N4-hyroxycytidine exhibited potent toxicity, as it interfered with blastocyst formation and caused extensive cell death at concentrations below the therapeutic plasma levels. The adverse effects of N4-hydroxycytidine were dependent on the timing of exposure, such that treatment after the 8-cell stage, but not before it, caused embryotoxicity. Transcriptomic analysis of N4-hydroxycytidine-exposed embryos, together with the examination of eIF-2a protein phosphorylation level, suggested that N4-hydroxycytidine induced the integrated stress response. The adverse effects of N4-hydroxycytidine were significantly alleviated by the co-treatment with S-(4-nitrobenzyl)-6-thioinosine, suggesting that the embryotoxic potential of N4-hydroxycytidine requires the activity of nucleoside transporters. These findings show that the active metabolite of molnupiravir impairs preimplantation development at clinically relevant concentrations, providing mechanistic foundation for further studies on the embryotoxic potential of molnupiravir and other related nucleoside antivirals.

Real-world clinical outcomes of treatment with molnupiravir for patients with mild-to-moderate coronavirus disease 2019 during the Omicron variant pandemic

It is unclear whether molnupiravir has a beneficial effect on vaccinated patients infected with the Omicron variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We here evaluated the efficacy of molnupiravir in patients with mild-to-moderate coronavirus disease 2019 (COVID-19) during the Omicron variant surge in Fukushima Prefecture, Japan. We enrolled patients with mild-to-moderate COVID-19 who were admitted to hospitals between January and April, 2022. Clinical deterioration after admission was compared between molnupiravir users (n = 230) and non-users (n  = 690) after 1:3 propensity score matching. Additionally, we performed forward stepwise multivariate logistic regression analysis to evaluate the association between clinical deterioration after admission and molnupiravir treatment in the 1:3 propensity score-matched subjects. The characteristics of participants in both groups were balanced as indicated by covariates with a standardized mean difference of < 0.1. Regarding comorbidities, there was no imbalance between the two groups, except for the presence of hypertension, dyslipidemia, diabetes mellitus, and cardiac disease. The clinical deterioration rate was significantly lower in the molnupiravir users compared to the non-users (3.90% vs 8.40%; P = 0.034). Multivariate logistic regression analysis demonstrated that receiving molnupiravir was a factor for preventing deterioration (odds ratio 0.448; 95% confidence interval 0.206-0.973; P = 0.042), independent of other covariates. This real-world study demonstrates that molnupiravir contributes to the prevention of deterioration in COVID-19 patients after hospitalization during the Omicron variant phase.

Molnupiravir for the treatment of COVID-19 in immunocompromised participants: efficacy, safety, and virology results from the phase 3 randomized, placebo-controlled MOVe-OUT trial

PURPOSE

Immunocompromised patients have a potentially increased risk for progression to severe COVID-19 and prolonged replication of SARS-CoV-2. This post hoc analysis examined outcomes among immunocompromised participants in the MOVe-OUT trial.

METHODS

In phase 3 of MOVe-OUT, non-hospitalized at-risk adults with mild-to-moderate COVID-19 were randomized to receive molnupiravir 800 mg or placebo twice daily for 5 days. Immunocompromised participants were identified based on prior/concomitant medications and/or medical history. All-cause hospitalization/death, adverse events, SARS-CoV-2 titers, infectivity, and RNA sequences were compared between immunocompromised participants who received molnupiravir or placebo and with non-immunocompromised participants.

RESULTS

Fifty-five of 1408 participants were considered immunocompromised. Compared to placebo, fewer molnupiravir-treated immunocompromised participants were hospitalized/died through Day 29 (22.6% [7/31] vs. 8.3% [2/24]), with fewer adverse events (45.2% [14/31] vs. 25.0% [6/24]). A larger mean change from baseline in SARS-CoV-2 RNA was observed with molnupiravir compared to placebo in non-immunocompromised participants (least squares mean [LSM] difference Day 5:  - 0.31, 95% confidence interval [CI]  - 0.47 to  - 0.15), while the mean change was comparable between treatment groups in immunocompromised participants (LSM difference Day 5: 0.23, 95% CI  - 0.71 to 1.17). Molnupiravir treatment was associated with increased clearance of infectious virus. Increased errors in viral nucleotide sequences in post-baseline samples compared to placebo support molnupiravir's mechanism of action and were not associated with observation of novel treatment-emergent amino acid substitutions in immunocompromised participants.

CONCLUSION

Although the study population was small, these data suggest that molnupiravir treatment for mild-to-moderate COVID-19 in non-hospitalized immunocompromised adults is efficacious and safe and quickly reduces infectious SARS-CoV-2.

CLINICALTRIALS

GOV REGISTRATION NUMBER

NCT04575597.

Real life experience of molnupiravir as a treatment of SARS-CoV-2 infection in vaccinated and unvaccinated patients: a letter on its effectiveness at preventing hospitalization

BACKGROUND

The SARS-CoV-2 pandemic has prompted clinicians to develop an early and effective treatment of viral infections. To date, vaccines, monoclonal antibodies, and antivirals are the cornerstone of therapy for SARS-CoV-2. AIFA approved the prescription of molnupiravir on 30/12/2021. Molnupiravir is a prodrug that causes the accumulation of errors in the viral genome.

METHODS

We prescribed molnupiravir to a total of 74 patients in a range between 26 and 96 years old and followed-up them for 30 days. 10 patients affected by idiopathic pulmonary fibrosis (IPF) were treated.

RESULTS

The follow-up showed that all of the treated patients presented a regression of symptoms. No patients were hospitalized and/or showed sequelae after the infection by SARS-CoV-2, even though the examined population was older and with more co-morbidities than other patients treated with different antivirals.

CONCLUSION

Molnupiravir is safe and well-tolerated by patients with high-risk of progression to severe COVID. No patients were hospitalized or showed sequelae, including all patients affected by IPF.

Hospitalization Among Patients Treated With Molnupiravir: A Retrospective Study of Administrative Data

PURPOSE

Molnupiravir is an oral antiviral agent authorized for emergency use to treat mild to moderate cases of coronavirus disease 2019 (COVID-19) in adults at high risk for progression to severe clinical outcomes. This study aimed to describe patient characteristics and health outcomes in a cohort of adult patients treated with molnupiravir in an outpatient setting in the United States.

METHODS

This was a retrospective cohort study of adults identified in the HealthVerity database with a pharmacy claim for molnupiravir between December 24, 2021, and April 14, 2022. Hospitalization and health care use were assessed over the 28 days after the molnupiravir pharmacy claim.

FINDINGS

Among 26,554 patients identified, 71.1% were aged ≥50 years and 58.9% were female. A total of 8794 patients (33.1%) had received at least 1 dose of the COVID-19 vaccine. The most prevalent risk factors for severe COVID-19 identified were hypertension (45.1%), steroid and/or immunosuppressant use (39.6%), and being obese or overweight (24.6%), with 79.1% of patients having ≥1 risk factor. The majority (61.0%) of patients were prescribed comedications contraindicated with or had the potential for major drug-drug interactions with ritonavir-containing regimens. Within 28 days after initiating molnupiravir, 3.3% of patients were hospitalized for any cause and 1.7% for COVID-19-related reasons. Among all hospitalized patients, 9.2% were admitted to an intensive care unit, 3.9% received oxygen, and 3.8% required mechanical ventilation.

IMPLICATIONS

The majority of patients treated with molnupiravir in early 2022 had at least one risk factor for severe COVID-19 and had comedications that could require treatment modification or monitoring if given a ritonavir-containing regimen. Hospitalization was uncommon after treatment with molnupiravir, with COVID-19-related inpatient admission in <2% of patients. Among those hospitalized, patient use of intensive care and oxygen-based resources was infrequent. The study design, however, does not permit any conclusions regarding the effectiveness of molnupiravir.

Biotransformation and brain distribution of the anti-COVID-19 drug molnupiravir and herb-drug pharmacokinetic interactions between the herbal extract Scutellaria formula-NRICM101

The aim of this study was to explore the effects of herbal drug pharmacokinetic interactions on the biotransformation of molnupiravir and its metabolite β-D-N4-hydroxycytidine (NHC) in the blood and brain. To investigate the biotransformation mechanism, a carboxylesterase inhibitor, bis(4-nitrophenyl)phosphate (BNPP), was administered. Not only molnupiravir but also the herbal medicine Scutellaria formula-NRICM101 is potentially affected by coadministration with molnupiravir. However, the herb-drug interaction between molnupiravir and the Scutellaria formula-NRICM101 has not yet been investigated. We hypothesized that the complex bioactive herbal ingredients in the extract of the Scutellaria formula-NRICM101, the biotransformation and penetration of the bloodbrain barrier of molnupiravir are altered by inhibition of carboxylesterase. To monitor the analytes, ultrahigh-performance liquid chromatography tandem mass spectrometry (UHPLCMS/MS) coupled with the microdialysis method was developed. Based on the dose transfer from humans to rats, a dose of molnupiravir (100 mg/kg, i.v.), molnupiravir (100 mg/kg, i.v.) + BNPP (50 mg/kg, i.v.), and molnupiravir (100 mg/kg, i.v.) + the Scutellaria formula-NRICM101 extract (1.27 g/kg, per day, for 5 consecutive days) were administered. The results showed that molnupiravir was rapidly metabolized to NHC and penetrated into the brain striatum. However, when concomitant with BNPP, NHC was suppressed, and molnupiravir was enhanced. The blood-to-brain penetration ratios were 2% and 6%, respectively. In summary, the extract of the Scutellaria formula-NRICM101 provides a pharmacological effect similar to that of the carboxylesterase inhibitor to suppress NHC in the blood, and the brain penetration ratio was increased, but the concentration is also higher than the effective concentration in the blood and brain.

Transfer and biotransformation of the COVID-19 prodrug molnupiravir and its metabolite β-D-N4-hydroxycytidine across the blood-placenta barrier

BACKGROUND

Molnupiravir is an orally bioavailable prodrug of the nucleoside analogue β-D-N4-hydroxycytidine (NHC) and is used to treat coronavirus disease 2019 (COVID-19). However, the pharmacokinetics and transplacental transfer of molnupiravir in pregnant women are still not well understood. In the present study, we investigated the hypothesis that molnupiravir and NHC cross the blood-placenta barrier into the fetus.

METHODS

A multisite microdialysis coupled with a validated ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC‒MS/MS) system was developed to monitor the dialysate levels of molnupiravir and NHC in maternal rat blood and conceptus (the collective term for the fetus, placenta, and amniotic fluid). Molnupiravir was administered intravenously (100 mg/kg, i.v.) on gestational day 16. To investigate the mechanism of transport of molnupiravir across the blood-placenta barrier, we coadministered nitrobenzylthioinosine (NBMPR, 10 mg/kg, i.v.) to inhibit equilibrative nucleoside transporter (ENT).

FINDINGS

We report that molnupiravir is rapidly metabolized to NHC and then rapidly transformed in the fetus, placenta, amniotic fluid, and maternal blood. Our pharmacokinetics analysis revealed that the area under the concentration curve (AUC) for the mother-to-fetus ratio (AUCfetus/AUCblood) of NHC was 0.29 ± 0.11. Further, we demonstrated that the transport of NHC in the placenta may not be subject to modulation by the ENT.

INTERPRETATION

Our results show that NHC is the predominant bioactive metabolite of molnupiravir and rapidly crosses the blood-placenta barrier in pregnant rats. The NHC concentration in maternal blood and conceptus was above the average median inhibitory concentration (IC50) for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), suggesting a therapeutic effect. These findings support the use of molnupiravir in pregnant patients infected with COVID.

FUNDING

This study was supported in part by research grants from the National Science and Technology Council of Taiwan (NSTC 111-2113-M-A49-018 and NSTC 112-2321-B-A49-005).

Real-life comparison of mortality in patients with SARS-CoV-2 infection at risk for clinical progression treated with molnupiravir or nirmatrelvir plus ritonavir during the Omicron era in Italy: a nationwide, cohort study

Background

Comparative data on mortality in COVID-19 patients treated with molnupiravir or with nirmatrelvir plus ritonavir are inconclusive. We therefore compared all-cause mortality in community-dwelling COVID-19 patients treated with these drugs during the Omicron era.

Methods

Data collected in the nationwide, population-based, cohort of patients registered in the database of the Italian Medicines Agency (AIFA) were used. To increase completeness of the recorded deaths and date correctness, a cross-check with the National Death Registry provided by the Ministry of the Interior was performed. We included in this study all patients infected by SARS-CoV-2 treated within 5 days after the test date and symptom onset between February 8 and April 30, 2022. All-cause mortalities by day 28 were compared between the two treatment groups after balancing for baseline characteristics using weights obtained from a gradient boosting machine algorithm.

Findings

In the considered timeframe, 17,977 patients treated with molnupiravir and 11,576 patients with nirmatrelvir plus ritonavir were included in the analysis. Most patients (25,617/29,553 = 86.7%) received a full vaccine course including the booster dose. A higher crude incidence rate of all-cause mortality was found among molnupiravir users (51.83 per 100,000 person-days), compared to nirmatrelvir plus ritonavir users (22.29 per 100,000 person-days). However, molnupiravir-treated patients were older than those treated with nirmatrelvir plus ritonavir and differences between the two populations were found as far as types of co-morbidities were concerned. For this reason, we compared the weight-adjusted cumulative incidences using the Aalen estimator and found that the adjusted cumulative incidence rates were 1.23% (95% CI 1.07%-1.38%) for molnupiravir-treated and 0.78% (95% CI 0.58%-0.98%) for nirmatrelvir plus ritonavir-treated patients (adjusted log rank p = 0.0002). Moreover, the weight-adjusted mixed-effect Cox model including Italian regions and NHS centers as random effects and treatment as the only covariate confirmed a significant reduced risk of death in patients treated with nirmatrelvir plus ritonavir. Lastly, a significant reduction in the risk of death associated with nirmatrelvir plus ritonavir was confirmed in patient subgroups, such as in females, fully vaccinated patients, those treated within day 2 since symptom onset and patients without (haemato)-oncological diseases.

Interpretation

Early initiation of nirmatrelvir plus ritonavir was associated for the first time with a significantly reduced risk of all-cause mortality by day 28 compared to molnupiravir, both in the overall population and in patient subgroups, including those fully vaccinated with the booster dose.

Funding

This study did not receive funding.

Molnupiravir for treatment of adults with mild or moderate COVID-19: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

The effects of molnupiravir in treating patients with non-severe COVID-19 remain uncertain.

OBJECTIVES

To evaluate the efficacy and safety of molnupiravir in adult patients with mild or moderate COVID-19.

DATA SOURCES

PubMed, Embase, CENTRAL, Web of Science, and WHO COVID-19 database up to 27 December 2022.

STUDY ELIGIBILITY CRITERIA

Randomized controlled trials with no language restrictions.

PARTICIPANTS

Adults with mild or moderate COVID-19.

INTERVENTIONS

Molnupiravir against standard care or placebo.

ASSESSMENT OF RISK OF BIAS

We used a revision of RoB-2 criteria.

METHODS OF DATA SYNTHESIS

Outcomes were mortality, hospital admission, viral clearance, time to viral clearance, time to symptom resolution or clinical improvement, any adverse events, and serious adverse events. We performed DerSimonian-Laird random-effects meta-analyses to summarize the evidence and evaluated the certainty of evidence using the Grading of Recommendations Assessment, Development, and Evaluation approach.

RESULTS

Nine randomized controlled trials enrolling 30 472 patients proved eligible. Majority of patients were outpatients, with a mean age ranging from 35 to 56.6 years. In adult patients with mild or moderate COVID-19, molnupiravir probably reduces mortality (relative risk [RR], 0.43; 95% CI, 0.20-0.94; risk difference [RD], 0.1% fewer; moderate certainty) and the risk of hospital admission (RR, 0.67; 95% CI, 0.45-0.99; RD, 1.4% fewer; moderate certainty) and may reduce time to viral clearance (mean difference, -1.81 days; 95% CI, -3.31 to -0.31; low certainty) and time to symptom resolution or clinical improvement (mean difference, -2.39 days; 95% CI, -3.71 to -1.07; low certainty). Molnupiravir probably increases the rate of viral clearance (RR, 3.47; 95% CI, 2.43-4.96; RD 16.1% more; moderate certainty) at 7 days (±3 days) and likely does not increase serious adverse events (RR, 0.84; 95% CI, 0.61-1.15; RD 0.1% fewer; moderate certainty).

CONCLUSIONS

In adult patients with mild or moderate COVID-19, molnupiravir likely reduces mortality and risk of hospital admission probably without increasing serious adverse events.

Efficacy and safety of Molnupiravir in COVID-19 patients: a systematic review

BACKGROUND

Molnupiravir is an oral antiviral drug that received Emergency Use Authorization in three countries for the treatment of mild COVID-19. The aim of this systematic review was to find out the safety and efficacy of Molnupiravir in SARS-COV-2 infections.

METHODS

The electronic databases such as PubMed, MedRxiv, BioRxiv, FDA, ClinicalTrials.Gov, ctri.nic.in and Google Scholar were searched for articles from January 2021 to March 2022 using the keywords such as "Molnupiravir", "COVID-19", "Oral antiviral pill", "MK-4482", "EIDD-280", "Efficacy" and "Safety". Details of published, unpublished with interim reports and ongoing studies of Molnupiravir in COVID-19 were retrieved, and a systematic review was performed.

RESULTS

A total of 6 articles and 18 ongoing trials data were collected. Out of these, data from 4 published and 2 unpublished with interim reports were extracted. After review of these studies, it was observed that the daily dose of 1600 mg Molnupiravir for 5 days was safe and tolerable with nausea, diarrhea and headache as the common adverse effects. The results also showed significant decrease in time to viral clearance with 800 mg twice daily in mild patients and reduction in the risk of hospitalization or death by 50% in non-hospitalized COVID-19 patients.

CONCLUSION

Evidence from clinical studies showed that Molnupiravir caused significant reduction in the risk of hospitalization or death in high-risk mild COVID-19 patients. Molnupiravir was also found to be well tolerated and safe without any major adverse events on short-term use. For confirmative use of this drug in mild-to-moderate COVID-19 disease, further studies are required in vaccinated COVID-19 patients and against emerging variants.

Estimation of Intangible Costs for Factors Associated with Oral Antiviral Drugs for COVID-19 Treatment: A Conjoint Analysis in Japan

INTRODUCTION

During the recent coronavirus disease 2019 (COVID-19) pandemic, preferences for factors associated with vaccines have been evaluated. Three oral antiviral drugs have been approved in Japan for patients with mild-to-moderate I COVID-19 symptoms. Although preferences for the drugs may also depend on various factors, these have not been fully evaluated.

METHODS

A conjoint analysis was performed based on an online survey in August 2022 to estimate the intangible costs of factors associated with oral antiviral drugs for COVID-19. Respondents were individuals aged 20-69 across Japan. The attributes included the company (Japanese/foreign) that developed the drug, formulation and size of the drug, frequency of administration per day, number of tablets/capsules per dose, number of days until no longer infectious to others, and out-of-pocket expenses. A logistic regression model was applied to estimate the utility of each level for each attribute. The intangible costs were calculated by comparing the utility to the out-of-pocket attribute.

RESULTS

Responses were collected from 11,303 participants. The difference between levels was the largest for companies that developed a drug; the intangible costs were JPY 5390 higher for the foreign company than for the Japanese company. The next largest difference was in the number of days until one is no longer infectious. For the same formulation, the intangible cost was lower for small sizes than large sizes. For similar-sized tablets and capsules, the intangible cost was lower for tablets than capsules. These tendencies were similar regardless of COVID-19 infection history and the presence of risk factors for severe COVID-19 in the respondents.

CONCLUSION

Intangible costs for factors associated with oral antiviral drugs among the Japanese population were estimated. The results may change as the number of people with a history of COVID-19 infection increases and significant progress is made regarding treatments.

Assessment of the frequency of SARS-CoV-2 Omicron variant escape from RNA-dependent RNA polymerase inhibitors and 3C-like protease inhibitors

The emergence and spread of antiviral-resistant SARS-CoV-2 is of great concern. In this study, we evaluated the propensity of Omicron variants to escape from RNA-dependent RNA polymerase (RdRP) inhibitors and 3C-like protease (3CLpro) inhibitors. SARS-CoV-2 Delta and Omicron variants were serially passaged in vitro in the presence of RdRP inhibitors (remdesivir and molnupiravir) and 3CLpro inhibitors (nirmatrelvir and lufotrelvir) to detect SARS-CoV-2 escape mutants. After five passages with 3CLpro inhibitors, mutant viruses that escaped from 3CLpro inhibitors emerged; however, in the presence of RdRP inhibitors all variants disappeared within 2-4 passages. Our findings suggest that the frequency of SARS-CoV-2 mutant escape from RdRP inhibitors is lower than that from 3CLpro inhibitors. We also found that Delta variants were more likely to acquire amino acid substitutions associated with resistance to 3CLpro inhibitors under the selective pressure of this drug compared with Omicron variants.

Interactions of the Anti-SARS-CoV-2 Agents Molnupiravir and Nirmatrelvir/Paxlovid with Human Drug Transporters

Orally administered small molecules may have important therapeutic potential in treating COVID-19 disease. The recently developed antiviral agents, Molnupiravir and Nirmatrelvir, have been reported to be efficient treatments, with only moderate side effects, especially when applied in the early phases of this disease. However, drug-drug and drug-transporter interactions have already been noted by the drug development companies and in the application notes. In the present work, we have studied some of the key human transporters interacting with these agents. The nucleoside analog Molnupiravir (EIDD-2801) and its main metabolite (EIDD-1931) were found to inhibit CNT1,2 in addition to the ENT1,2 nucleoside transporters; however, it did not significantly influence the relevant OATP transporters or the ABCC4 nucleoside efflux transporter. The active component of Paxlovid (PF-07321332, Nirmatrelvir) inhibited the function of several OATPs and of ABCB1 but did not affect ABCG2. However, significant inhibition was observed only at high concentrations of Nirmatrelvir and probably did not occur in vivo. Paxlovid, as used in the clinic, is a combination of Nirmatrelvir (viral protease inhibitor) and Ritonavir (a "booster" inhibitor of Nirmatrelvir metabolism). Ritonavir is known to inhibit several drug transporters; therefore, we have examined these compounds together, in relevant concentrations and ratios. No additional inhibitory effect of Nirmatrelvir was observed compared to the strong transporter inhibition caused by Ritonavir. Our current in vitro results should help to estimate the potential drug-drug interactions of these newly developed agents during COVID-19 treatment.

Potential herb‒drug interactions between anti-COVID-19 drugs and traditional Chinese medicine

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has spread worldwide. Effective treatments against COVID-19 remain urgently in need although vaccination significantly reduces the incidence, hospitalization, and mortality. At present, antiviral drugs including Nirmatrelvir/Ritonavir (Paxlovid^TM), Remdesivir, and Molnupiravir have been authorized to treat COVID-19 and become more globally available. On the other hand, traditional Chinese medicine (TCM) has been used for the treatment of epidemic diseases for a long history. Currently, various TCM formulae against COVID-19 such as Qingfei Paidu decoction, Xuanfei Baidu granule, Huashi Baidu granule, Jinhua Qinggan granule, Lianhua Qingwen capsule, and Xuebijing injection have been widely used in clinical practice in China, which may cause potential herb-drug interactions (HDIs) in patients under treatment with antiviral drugs and affect the efficacy and safety of medicines. However, information on potential HDIs between the above anti-COVID-19 drugs and TCM formulae is lacking, and thus this work seeks to summarize and highlight potential HDIs between antiviral drugs and TCM formulae against COVID-19, and especially pharmacokinetic HDIs mediated by metabolizing enzymes and/or transporters. These well-characterized HDIs could provide useful information on clinical concomitant medicine use to maximize clinical outcomes and minimize adverse and toxic effects.

Comparison of the acceptability and safety of molnupiravir in COVID-19 patients aged over and under 80 years

Background

Molnupiravir is being widely used as a treatment for coronavirus disease 2019 (COVID-19); however, its acceptability and safety in older patients aged ≥ 80 years in real-world clinical practice is not well understood.

Methods

We conducted a single-centre retrospective study and assessed the outcome of patients with COVID-19 treated with molnupiravir according to the following criteria: (A) discontinuation rate of molnupiravir; (B) type, frequency, and severity of adverse events; (C) all-cause mortality within 30 days of the diagnosis of COVID-19.

Results

Forty-seven patients (46.1%) were aged ≥ 80 years (older patients) and 55 (53.9%) were aged < 80 years (younger patients). There were no significant differences in coexisting diseases and history of vaccination for COVID-19 between older and younger patients. Older patients were significantly more likely to have moderate disease (moderate 1 and 2) according to the Japanese Ministry of Health, Labour and Welfare classification than younger patients. During treatment, 8.5% of older patients and 1.8% of younger patients stopped taking molnupiravir, but the difference was not significant. Adverse events were observed in 39/102 (38.2%) patients. The most common adverse events were diarrhoea (9.8%), exacerbation of coexisting diseases (6.9%), bone marrow suppression (6.9%), liver dysfunction (5.9%), and loss of appetite (4.9%). Most adverse events were minor, ranging from grades 1 to 3. The all-cause mortality rate was 10.8%, and no molnupiravir-related deaths were observed.

Conclusions

Molnupiravir treatment is acceptable and safe in older patients with COVID-19 aged ≥ 80 years.

Evaluation of antiviral drugs against newly emerged SARS-CoV-2 Omicron subvariants

Ongoing emergence of SARS-CoV-2 Omicron subvariants and their rapid worldwide spread pose a threat to public health. From November 2022 to February 2023, newly emerged Omicron subvariants, including BQ.1.1, BF.7, BA.5.2, XBB.1, XBB.1.5, and BN.1.9, became prevalent global strains (>5% global prevalence). These Omicron subvariants are resistant to several therapeutic antibodies. Thus, the antiviral activity of current drugs such as remdesivir, molnupiravir, and nirmatrelvir, which target highly conserved regions of SARS-CoV-2, against newly emerged Omicron subvariants need to be evaluated. We assessed the antiviral efficacy of the drugs using the half-maximal inhibitory concentration (IC50) against human isolates of 23 Omicron subvariants and four former SARS-CoV-2 variants of concern (VOCs) and compared it with the antiviral efficacy of these drugs against the SARS-CoV-2 reference strain (hCoV/Korea/KCDC03/2020). Maximal IC50-fold changes of remdesivir, molnupiravir, and nirmatrelvir were 1.9 (BA.2.75.2), 1.2 (B.1.627.2), and 1.4 (BA.2.3), respectively, compared to median IC50 values of the reference strain. Moreover, median IC50-fold changes of remdesivir, molnupiravir, and nirmatrelvir against the Omicron variants were 0.96, 0.4, and 0.62, respectively, similar to the 1.02, 0.88, and 0.67, respectively, median IC50-fold changes for previous VOCs. Although K90R and P132H in Nsp 5, and P323L, A529V, G671S, V405F, and ins823D in Nsp 12 mutations were identified, these amino acid substitutions did not affect drug antiviral activity. These results indicate that current antivirals retain antiviral efficacy against newly emerged Omicron subvariants. It is important to continue active surveillance and testing of new variants for drug resistance to enable early identification of drug-resistant strains.

Antiviral Treatment of Coronavirus Disease-2019 Pneumonia

Direct acting antivirals and monoclonal antibodies reduce morbidity and mortality associated with severe acute respiratory syndrome coronavirus 2 infection. Persons at higher risk for disease progression and hospitalized patients with coronavirus disease-2019 (COVID-19) benefit most from available therapies. Following an emphasis on inpatient treatment of COVID-19 during the early pandemic, several therapeutic options were developed for outpatients with COVID-19. Additional clinical trials and real-world studies are needed to keep pace with the evolving pandemic.

Sustainable Stability-Indicating spectra manipulations for the concurrent quantification of a novel Anti-COVID-19 drug and its active Metabolite: Green profile assessment

Millions of individuals have lost their lives and changed their routines as a direct consequence of exposure to the coronavirus (Covid-19). Molnupiravir (MOL) is an orally bioavailable tiny molecule antiviral prodrug that is effective for curing the coronavirus that produces serious acute respiratory disorder (SARS-CoV-2). Fully green-assessed stability-indicating simple spectrophotometric methods have been developed and fully validated as per ICH criteria. The potential impact of degradation products of drug components on the safety and efficacy of a medication's shelf life is likely to be negligible. The field of pharmaceutical analysis necessitates various stability testing under different conditions. The conduct of such inquiries affords the prospect of predicting the most probable routes of degradation and ascertaining the inherent stability characteristics of the active drugs. Consequently, a surge in demand arose for the creation of an analytical methodology that could consistently measure the degradation products and/or impurities that may be present in pharmaceuticals. Herein, five smart and simple spectrophotometric data manipulation techniques have been produced for the concurrent estimation of MOL and its active metabolite as its possible acid degradation product namely; N-hydroxycytidine (NHC). Structure confirmation of NHC build-up through IR, MS and NMR analyses. All current techniques verified linearity ranging from 10 to 150 μg/ml and 10-60 μg/ml for MOL and NHC, respectively. The limit of quantitation (LOQ) values were in the range of 4.21-9.59 μg/ml, while the limit of detection (LOD) values were ranging from 1.38 - 3.16 μg/ml. The current methods were evaluated in terms of greenness by four assessing methods and confirmed to be green. The significant novelty of these methods depends on their being the first environmentally soundness stability-indicating spectrophotometric approaches for the concurrent estimation of MOL and its active metabolite, NHC. Also, the preparation of purified NHC delivers significant cost savings, instead of purchasing an expensive ingredient. These smart methods were utilized for analyzing the pharmaceutical dosage form which may be of great benefit to the pharmaceutical market.

Molnupiravir, Nirmatrelvir/Ritonavir, or Sotrovimab for High-Risk COVID-19 Patients Infected by the Omicron Variant: Hospitalization, Mortality, and Time until Negative Swab Test in Real Life

Background. Several drugs which are easy to administer in outpatient settings have been authorized and endorsed for high-risk COVID-19 patients with mild-moderate disease to prevent hospital admission and death, complementing COVID-19 vaccines. However, the evidence on the efficacy of COVID-19 antivirals during the Omicron wave is scanty or conflicting. Methods. This retrospective controlled study investigated the efficacy of Molnupiravir or Nirmatrelvir/Ritonavir (Paxlovid®) or Sotrovimab against standard of care (controls) on three different endpoints among 386 high-risk COVID-19 outpatients: hospital admission at 30 days; death at 30 days; and time between COVID-19 diagnosis and first negative swab test result. Multivariable logistic regression was employed to investigate the determinants of hospitalization due to COVID-19-associated pneumonia, whereas time to first negative swab test result was investigated by means of multinomial logistic analysis as well as Cox regression analysis. Results. Only 11 patients (overall rate of 2.8%) developed severe COVID-19-associated pneumonia requiring admission to hospital: 8 controls (7.2%); 2 patients on Nirmatrelvir/Ritonavir (2.0%); and 1 on Sotrovimab (1.8%). No patient on Molnupiravir was institutionalized. Compared to controls, hospitalization was less likely for patients on Nirmatrelvir/Ritonavir (aOR = 0.16; 95% CI: 0.03; 0.89) or Molnupiravir (omitted estimate); drug efficacy was 84% for Nirmatrelvir/Ritonavir against 100% for Molnupiravir. Only two patients died of COVID-19 (rate of 0.5%), both were controls, one (a woman aged 96 years) was unvaccinated and the other (a woman aged 72 years) had adequate vaccination status. At Cox regression analysis, the negativization rate was significantly higher in patients treated with both antivirals-Nirmatrelvir/Ritonavir (aHR = 1.68; 95% CI: 1.25; 2.26) or Molnupiravir (aHR = 1.45; 95% CI: 1.08; 1.94). However, COVID-19 vaccination with three (aHR = 2.03; 95% CI: 1.51; 2.73) or four (aHR = 2.48; 95% CI: 1.32; 4.68) doses had a slightly stronger effect size on viral clearance. In contrast, the negativization rate reduced significantly in patients who were immune-depressed (aHR = 0.70; 95% CI: 0.52; 0.93) or those with a Charlson index ≥5 (aHR = 0.63; 0.41; 0.95) or those who had started the respective treatment course 3+ days after COVID-19 diagnosis (aOR = 0.56; 95% CI: 0.38; 0.82). Likewise, at internal analysis (excluding patients on standard of care), patients on Molnupiravir (aHR = 1.74; 95% CI: 1.21; 2.50) or Nirmatrelvir/Ritonavir (aHR = 1.96; 95% CI: 1.32; 2.93) were more likely to turn negative earlier than those on Sotrovimab (reference category). Nonetheless, three (aHR = 1.91; 95% CI: 1.33; 2.74) or four (aHR = 2.20; 95% CI: 1.06; 4.59) doses of COVID-19 vaccine were again associated with a faster negativization rate. Again, the negativization rate was significantly lower if treatment started 3+ days after COVID-19 diagnosis (aHR = 0.54; 95% CI: 0.32; 0.92). Conclusions. Molnupiravir, Nirmatrelvir/Ritonavir, and Sotrovimab were all effective in preventing hospital admission and/or mortality attributable to COVID-19. However, hospitalizations also decreased with higher number of doses of COVID-19 vaccines. Although they are effective against severe disease and mortality, the prescription of COVID-19 antivirals should be carefully scrutinized by double opinion, not only to contain health care costs but also to reduce the risk of generating resistant SARS-CoV-2 strains. Only 64.7% of patients were in fact immunized with 3+ doses of COVID-19 vaccines in the present study. High-risk patients should prioritize COVID-19 vaccination, which is a more cost-effective approach than antivirals against severe SARS-CoV-2 pneumonia. Likewise, although both antivirals, especially Nirmatrelvir/Ritonavir, were more likely than standard of care and Sotrovimab to reduce viral shedding time (VST) in high-risk SARS-CoV-2 patients, vaccination had an independent and stronger effect on viral clearance. However, the effect of antivirals or COVID-19 vaccination on VST should be considered a secondary benefit. Indeed, recommending Nirmatrelvir/Ritonavir in order to control VST in high-risk COVID-19 patients is rather questionable since other cheap, large spectrum and harmless nasal disinfectants such as hypertonic saline solutions are available on the market with proven efficacy in containing VST.

Potential RNA-dependent RNA polymerase (RdRp) inhibitors as prospective drug candidates for SARS-CoV-2

The SARS-CoV-2 pandemic is considered as one of the most disastrous pandemics for human health and the world economy. RNA-dependent RNA polymerase (RdRp) is one of the key enzymes that control viral replication. RdRp is an attractive and promising therapeutic target for the treatment of SARS-CoV-2 disease. It has attracted much interest of medicinal chemists, especially after the approval of Remdesivir. This study highlights the most promising SARS-CoV-2 RdRp repurposed drugs in addition to natural and synthetic agents. Although many in silico predicted agents have been developed, the lack of in vitro and in vivo experimental data has hindered their application in drug discovery programs.

Safety and Effectiveness of Molnupiravir (LAGEVRIO®) Capsules in Japanese Patients with COVID-19: Interim Report of Post-marketing Surveillance in Japan

INTRODUCTION

Molnupiravir is an oral antiviral drug that received special approval for emergency use in Japan on December 24 2021 for infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This post-marketing surveillance (PMS) is underway to investigate the safety and effectiveness of molnupiravir in daily clinical practice in Japan. The interim PMS data collected from December 27 2021 to June 15 2022 are reported in this publication.

METHODS

This survey included adult Japanese patients treated with molnupiravir. For safety, adverse drug reactions (ADR) were assessed by physicians. Effectiveness was assessed by the composite endpoint of (1) hospitalization or (2) death in outpatients and by the composite endpoint of (3) death or (4) initiation of oxygen administration/mechanical ventilation in inpatients hospitalized for any reasons and without oxygen administration at the start of molnupiravir administration. The observation period was through 29 days from the start of molnupiravir administration.

RESULTS

Of the 1031 patients in the safety analysis set, 68 (6.60%) patients reported ADRs and four (0.39%) patients reported serious ADRs. The main ADRs observed were diarrhoea [26 patients (2.52%)], rash [six patients (0.58%)], dizziness [five patients (0.48%)], and faeces soft [four patients (0.39%)]. In the effectiveness analysis from the start date of molnupiravir administration to day 29, there were 16/612 (2.61%) hospitalizations and no deaths. Oxygen administration was newly initiated in 9/199 (4.52%) inpatients after the initiation of molnupiravir administration; 2/199 (1.01%) inpatients died.

CONCLUSION

This interim analysis of molnupiravir in daily clinical practice use in Japan supports the safety and effectiveness profile of molnupiravir under pandemic conditions in which Omicron was the dominant SARS-CoV-2 variant. The results of this PMS will provide valuable information for daily clinical practice use.

Earth-friendly-assessed silver-nanoparticles spectrophotometric method for rapid and sensitive analysis of Molnupiravir, an FDA-approved candidate for COVID-19: application on pharmaceutical formulation and dissolution test

Molnupiravir is the first oral direct-acting antiviral prodrug recently approved for the COVID-19 pandemic. Here and for the first time, we present a novel, sensitive, robust, and simple silver-nanoparticles spectrophotometric technique for molnupiravir analysis in its capsules and dissolution media. This spectrophotometric technique involved silver-nanoparticles synthesis through a redox reaction between the reducing agent (molnupiravir) and the oxidizing agent (silver nitrate) in presence of polyvinylpyrrolidone as a stabilizing agent. The produced silver-nanoparticles have an intense surface plasmon resonance peak at 416 nm where the measured absorbance values were utilized for the quantitative analysis of molnupiravir. The produced silver-nanoparticles were recognized by using the transmission electron microscope. Under optimal conditions, a good linear rapport was accomplished between molnupiravir concentrations and the corresponding absorbance values in a range of (100-2000) ng/mL with a detection limit of 30 ng/mL. Greenness assessment was implemented using eco-scale scoring and GAPI disclosing the excellent greenness of the suggested technique. The suggested silver-nanoparticles technique was authenticated according to recommendations of the ICH and statistically assessed with the reported liquid chromatographic method without significant differences regarding accuracy or precision. Accordingly, the suggested technique is deemed a green and cheap alternative for assaying molnupiravir due to its reliance primarily on water. Furthermore, the suggested technique's high sensitivity can be employed for investigating molnupiravir bioequivalence in future studies.

Characteristics and outcomes of US Veterans at least 65 years of age at high risk of severe SARS-CoV-2 infection with or without receipt of oral antiviral agents

OBJECTIVES

Molnupiravir and nirmatrelvir/ritonavir each became available in the United States (US) through the Food and Drug Administration (FDA) emergency use authorization (EUA) in December 2021 after their respective initial prospective randomized controlled trials demonstrated efficacy for patients with mild-to-moderate SARS-CoV-2 active infection considered to be at high risk for progression of disease and hospitalization. Although sufficiently powered for this wide group, the mean age for patients in these studies was only 43 and 46 years of age, respectively. We sought to compare outcomes of US Veterans 65 years and older who received either of these oral antivirals to those who did not receive oral antivirals for mild-to-moderate SARS-CoV-2 active infection.

METHODS

The current project was a retrospective, observational, nationwide propensity-matched analysis comparing outcomes of US Veterans 65 years and older who received either of these oral antivirals to US Veterans 65 years and older who did not receive oral antivirals for mild-to-moderate SARS-CoV-2 active infection.

RESULTS

The composite primary outcome of admission or death within 30 days of diagnosis was reached less often in those receiving either molnupiravir or nirmatrelvir/ritonavir versus those that received no antiviral (65/1370 [4.75%] vs. 139/1370 [10.2%]; odds ratio 0.44, 95% confidence interval 0.32-0.60, p<0.0001). Baseline differences between Veterans selected for molnupiravir vs. nirmatrelvir/ritonavir therapy were noted, particularly in the number of concomitant medications with cautions or contraindications with nirmatrelvir/ritonavir.

CONCLUSIONS

Our findings support the use of molnupiravir or nirmatrelvir/ritonavir in patients 65 years of age and older. Patients with higher medication caution and contraindication burdens to nirmatrelvir/ritonavir are selected for molnupiravir therapy, which in the absence of a prospective head-to-head trial, may limit any efforts to compare the effectiveness of the two drugs.

Current and Emerging Therapies for COVID-19 in Lung Transplantation

Purpose of Review

The landscape of the coronavirus disease 2019 (COVID-19) pandemic has rapidly changed over the past 3 years. Paralleling this evolution, the scientific and medical communities have reported many novel findings relating to the infection's epidemiology, transmission, diagnosis, and treatment. We review pertinent studies of COVID-19 therapeutics with an emphasis on their application to lung transplant recipients.

Recent Findings

Agents that have been well-studied for treating COVID-19 include antivirals (remdesivir, nirmatrelvir/ritonavir, molnupiravir), monoclonal antibodies, and immunomodulators (for example, corticosteroids and tocilizumab).

Summary

Remdesivir remains an essential therapy for managing mild-moderate COVID-19. Though highly efficacious for mild-moderate COVID-19 for outpatient therapy, ritonavir-boosted nirmatrelvir has limited use in lung transplant recipients due to significant drug-drug interactions. Monoclonal antibodies, though useful, are the most affected by the emergence of new viral variants.

Effectiveness of Favipiravir monotherapy in the treatment of COVID-19: Real world data analysis from Thailand

Background

Previous studies showed that Favipiravir, a selective viral ribonucleic acid dependent-ribonucleic acid polymerase inhibitor, exhibited a trend of clinical improvement within 14 days and promoted viral clearance by day 7, without reduction of mortality rate in COVID-19.

Methods

During the COVID-19 pandemic, Department of Medical Services (Thailand) formulated National Clinical Treatment Guidelines for COVID-19 and approved Favipiravir to eight medical centres. After treatment with Favipiravir monotherapy, we compared real-world data analysis to supportive treatment without antiviral agents.

Findings

We analysed 12,888 COVID-19 patients between June 1, 2021, and July 31, 2021. This group study excluded 66 asymptomatic and 4,634 COVID-19 patients treated with other antiviral agents. The 4,896 mild, 2,357 moderate, and 1,393 severe COVID-19 patients were analysed. All patients neither had previous SARS-CoV-2 infection nor received an mRNA vaccine during study period. Favipiravir monotherapy reduced the 28-day mortality risk in severe COVID-19 by relative risk (RR) = 0.72 (95% CI 0.58-0.91 P=0.006) after adjustment for aging and hypertension. However, in mild and moderate COVID-19, Favipiravir monotherapy did not significantly reduce 28-day mortality risk by RR = 0.59 (95% CI 0.06- 5.43 P=0.65) after adjustment for aging, and RR = 0.60 (95% CI 0.32-1.13 P=0.11) after adjustment for aging and obesity, respectively. In the patient with recovery, Favipiravir monotherapy exhibited a shortening time to recovery when compared to supportive treatment without antiviral agents (mean + SD by 9.6+ 7.1 vs. 12.9 +7.6 days: P<0.0001, 10.0+5.9 vs. 12.4 + 5.3 days: P<0.0001, and 11.2 +7.8 vs. 13.1+ 8.0 days: P<0.0001 in mild, moderate, and severe COVID-19 respectively).

Interpretation

Real-world data analysis showed that favipiravir monotherapy was superior to supportive treatment without antiviral agents in shortening the recovery time in surviving patients and significantly reducing 28-day mortality risk in severe COVID-19.

Funding

Department of Medical Services, Ministry of Public Health, Thailand.

SARS-CoV-2 RdRp uses NDPs as a substrate and is able to incorporate NHC into RNA from diphosphate form molnupiravir

The coronavirus disease 2019 has been ravaging throughout the world for three years and has severely impaired both human health and the economy. The causative agent, severe acute respiratory syndrome coronavirus 2 employs the viral RNA dependent RNA polymerase (RdRp) complex for genome replication and transcription, making RdRp an appealing target for antiviral drug development. Systematic characterization of RdRp will undoubtedly aid in the development of antiviral drugs targeting RdRp. Here, our research reveals that RdRp can recognize and utilize nucleoside diphosphates as a substrate to synthesize RNA with an efficiency of about two thirds of using nucleoside triphosphates as a substrate. Nucleoside diphosphates incorporation is also template-specific and has high fidelity. Moreover, RdRp can incorporate β-d-N4-hydroxycytidine into RNA while using diphosphate form molnupiravir as a substrate. This incorporation results in genome mutation and virus death. It is also observed that diphosphate form molnupiravir is a better substrate for RdRp than the triphosphate form molnupiravir, presenting a new strategy for drug design.