Real-world effectiveness of molnupiravir and nirmatrelvir plus ritonavir against mortality, hospitalisation, and in-hospital outcomes among community-dwelling, ambulatory patients with confirmed SARS-CoV-2 infection during the omicron wave in Hong Kong: an observational study

Real-World Effectiveness of Nirmatrelvir/Ritonavir on Coronavirus Disease 2019-Associated Hospitalization Prevention: A Population-based Cohort Study in the Province of Quebec, Canada

BACKGROUND

Nirmatrelvir/ritonavir has shown to reduce COVID-19 hospitalization and death before Omicron, but updated real-world evidence studies are needed. This study aimed to assess whether nirmatrelvir/ritonavir reduces the risk of COVID-19-associated hospitalization among high-risk outpatients.

METHODS

A retrospective cohort study of outpatients with SARS-CoV-2 between March 15 and 15 October 2022, using data from the Quebec clinico-administrative databases. Outpatients treated with nirmatrelvir/ritonavir were compared with infected ones not receiving nirmatrelvir/ritonavir using propensity-score matching. Relative risk (RR) of COVID-19-associated hospitalization within 30 days was assessed using a Poisson regression.

RESULTS

A total of 8402 treated outpatients were matched to controls. Regardless of vaccination status, nirmatrelvir/ritonavir treatment was associated with a 69% reduced RR of hospitalization (RR: .31; 95% CI: .28; .36; number needed to treat [NNT] = 13). The effect was more pronounced in outpatients with incomplete primary vaccination (RR: .04; 95% CI: .03; .06; NNT = 8), while no benefit was found in those with a complete primary vaccination (RR: .93; 95% CI: .78; 1.08). Subgroups analysis among high-risk outpatients with a complete primary vaccination showed that nirmatrelvir/ritonavir treatment was associated with a significant decrease in the RR of hospitalization in severely immunocompromised outpatients (RR: .66; 95% CI: .50; .89; NNT = 16) and in high-risk outpatients aged ≥70 years (RR: .50; 95% CI: .34; .74; NNT = 10) when the last dose of the vaccine was received at least 6 months ago.

CONCLUSIONS

Nirmatrelvir/ritonavir reduces the risk of COVID-19-associated hospitalization among incompletely vaccinated high-risk outpatients and among some subgroups of completely vaccinated high-risk outpatients.

Combating pan-coronavirus infection by indomethacin through simultaneously inhibiting viral replication and inflammatory response

Severe infections with coronaviruses are often accompanied with hyperinflammation, requiring therapeutic strategies to simultaneously tackle the virus and inflammation. By screening a safe-in-human broad-spectrum antiviral agents library, we identified that indomethacin can inhibit pan-coronavirus infection in human cell and airway organoids models. Combining indomethacin with oral antiviral drugs authorized for treating COVID-19 results in synergistic anti-coronavirus activity. Coincidentally, screening a library of FDA-approved drugs identified indomethacin as the most potent potentiator of interferon response through increasing STAT1 phosphorylation. Combining indomethacin with interferon-alpha exerted synergistic antiviral effects against multiple coronaviruses. The anti-coronavirus activity of indomethacin is associated with activating interferon response. In a co-culture system of lung epithelial cells with macrophages, indomethacin inhibited both viral replication and inflammatory response. Collectively, indomethacin is a pan-coronavirus inhibitor that can simultaneously inhibit virus-triggered inflammatory response. The therapeutic potential of indomethacin can be further augmented by combining it with oral antiviral drugs or interferon-alpha.

Application of clinical and CT imaging features in the evaluation of disease progression in patients with COVID-19

BACKGROUND

The Corona Virus Disease 2019(COVID-19) pandemic has strained healthcare systems worldwide, necessitating the early prediction of patients requiring critical care. This study aimed to analyze the laboratory examination indicators, CT features, and prognostic risk factors in COVID-19 patients.

METHODS

A retrospective study was conducted on 90 COVID-19 patients at the First Affiliated Hospital of Gannan Medical University between December 17, 2022, and March 17, 2023. Clinical data, laboratory examination results, and computed tomography (CT) imaging data were collected. Logistic multivariate regression analysis was performed to identify independent risk factors, and the predictive ability of each risk factor was assessed using the area under the receiver operating characteristic (ROC) curve.

RESULTS

Multivariate logistic regression analysis revealed that comorbid diabetes (odds ratio [OR] = 526.875, 95%CI = 1.384-1960.84, P = 0.053), lymphocyte count reduction (OR = 8.773, 95%CI = 1.432-53.584, P = 0.064), elevated D-dimer level (OR = 362.426, 95%CI = 1.228-984.995, P = 0.023), and involvement of five lung lobes (OR = 0.926, 95%CI = 0.026-0.686, P = 0.025) were risk factors for progression to severe COVID-19. ROC curve analysis showed the highest predictive value for 5 lung lobes (AUC = 0.782). Oxygen saturation was positively correlated with normally aerated lung volume and the proportion of normally aerated lung volume (P < 0.05).

CONCLUSIONS

The study demonstrated that comorbid diabetes, lymphocyte count reduction, elevated D-dimer levels, and involvement of the five lung lobes are significant risk factors for severe COVID-19. In CT lung volume quantification, normal aerated lung volume and the proportion of normal aerated lung volume correlated with blood oxygen saturation.

Impact of some antiviral drugs on health care utilization for patients with COVID-19: a systematic review and meta-analysis

BACKGROUND

We aimed to assess the impact of antiviral drugs (fluvoxamine,remdesivir, lopinavir/ritonavir (LPV/r), molnupiravir, andnirmatrelvir/ritonavir (NRV/r)) on health care utilization (HCU) inCOVID-19 patients. We summarized findings from randomized controlledtrials (RCTs) and observational studies.

METHODS

We systematically searched four medical databases (PubMed, Web of Science, Embase, Cochrane Library) for COVID-19 studies up to February 15, 2023. A comprehensive review, meta-analysis, sensitivity analysis, and subgroup analysis were conducted. Pooled effects with 95% confidence intervals (CIs) were calculated for antiviral drugs' impact on hospitalization, mechanical ventilation (MV), and intensive care unit (ICU) outcomes.

RESULTS

Our analysis included 34 studies (584,978 patients). Meta-analysisindicated potential benefits: remdesivir and molnupiravir potentiallyreduced MV risk, and NRV/r correlated with lower hospitalizationrates. However, LPV/r did not notably curb HCU. Remdesivir waspreferable for high-risk COVID-19 patients, while molnupiravir andNRV/r were recommended for those aged 60 and above.

CONCLUSION

Remdesivir, molnupiravir, and NRV/r may reduce HCU during the COVID-19 pandemic. However, due to limited study details and significant heterogeneity in effect estimates, further precise evidence is crucial, especially concerning emerging variants.

Bench-to-bedside: Innovation of small molecule anti-SARS-CoV-2 drugs in China

The ongoing COVID-19 pandemic has resulted in millions of deaths globally, highlighting the need to develop potent prophylactic and therapeutic strategies against SARS-CoV-2. Small molecule inhibitors (remdesivir, Paxlovid, and molnupiravir) are essential complements to vaccines and play important roles in clinical treatment of SARS-CoV-2. Many advances have been made in development of anti-SARS-CoV-2 inhibitors in China, but progress in discovery and characterization of pharmacological activity, antiviral mechanisms, and clinical efficacy are limited. We review development of small molecule anti-SARS-CoV-2 drugs (azvudine [approved by the NMPA of China on July 25, 2022], VV116 [approved by the NMPA of China on January 29, 2023], FB2001, WPV01, pentarlandir, and cepharanthine) in China and summarize their pharmacological activity, potential mechanisms of action, clinical trials and use, and important milestones in their discovery. The role of structural biology in drug development is also reviewed. Future studies should focus on development of diverse second-generation inhibitors with excellent oral bioavailability, superior plasma half-life, increased antiviral activity against SARS-CoV-2 and its variants, high target specificity, minimal side effects, reduced drug-drug interactions, and improved lung histopathology.

Nirmatrelvir or Molnupiravir Use and Severe Outcomes From Omicron Infections

Importance

Ritonavir-boosted nirmatrelvir and molnupiravir are currently used in the US and in other countries to treat nonhospitalized patients who have mild-to-moderate COVID-19 and who are at high risk for progression to severe disease. The associations of these 2 oral antiviral drugs with hospitalization and death resulting from infection with new SARS-CoV-2 Omicron subvariants, particularly BQ.1.1 and XBB.1.5, are unknown.

Objective

To assess the association of nirmatrelvir or molnupiravir use with the risks of hospitalization and death among patients infected with new Omicron subvariants.

Design, Setting, and Participants

This was a cohort study of patients who received a diagnosis of COVID-19 at Cleveland Clinic from April 1, 2022, to February 20, 2023 (during which the Omicron variant evolved from BA.2 to BA.4/BA.5, then to BQ.1/BQ.1.1, and finally to XBB/XBB.1.5) and who were at high risk of progressing to severe disease, with follow-up through 90 days after diagnosis. The final date for follow-up data collection was February 27, 2023.

Exposures

Treatment with ritonavir-boosted nirmatrelvir or molnupiravir.

Main Outcomes and Measures

The primary outcome was time to death. The secondary outcome was time to either hospitalization or death. The association of either nirmatrelvir or molnupiravir use with each outcome was measured by the hazard ratio (HR) adjusted for demographic factors, socioeconomic status, date of COVID-19 diagnosis, coexisting medical conditions, COVID-19 vaccination status, and previous SARS-CoV-2 infection.

Results

There were 68 867 patients (29 386 [42.7%] aged ≥65 years; 26 755 [38.9%] male patients; 51 452 [74.7%] non-Hispanic White patients). Thirty of 22 594 patients treated with nirmatrelvir, 27 of 5311 patients treated with molnupiravir, and 588 of 40 962 patients who received no treatment died within 90 days of Omicron infection. The adjusted HRs of death were 0.16 (95% CI, 0.11-0.23) for nirmatrelvir and 0.23 (95% CI, 0.16-0.34) for molnupiravir. The adjusted HRs of hospitalization or death were 0.63 (95% CI, 0.59-0.68) for nirmatrelvir and 0.59 (95% CI, 0.53-0.66) for molnupiravir. The associations of both drugs with both outcomes were observed across subgroups defined by age, race and ethnicity, date of COVID-19 diagnosis, vaccination status, previous infection status, and coexisting conditions.

Conclusions and Relevance

These findings suggest that the use of either nirmatrelvir or molnupiravir is associated with reductions in mortality and hospitalization in patients infected with Omicron, regardless of age, race and ethnicity, virus strain, vaccination status, previous infection status, or coexisting conditions. Both drugs can, therefore, be used to treat nonhospitalized patients who are at high risk of progressing to severe COVID-19.

COVID-19: An Update on Epidemiology, Prevention and Treatment, September-2023

After a downward trend for more than 12 months, the incidence of COVID-19 has increased in the last months. Although COVID-19 is not as frequent as in the first years of the pandemic, case numbers are still very high, and it causes a significant number of deaths. COVID-19 is not seen with a predictable frequency, at least two times more deadly than the flu, continues as an epidemic, and has not reached the endemic level yet. Currently, the Omicron strains EG.5 and XBB.1.16 are dominant worldwide. Although BA.2.86 and FLip variants, including FL.1.5.1 are not widespread at the moment, both were shown to be highly immune-evasive and require close monitoring. Prevention of COVID-19 relies on vaccinations, surveillance, proper ventilation of enclosed spaces, isolation of patients, and mask usage. Currently, monovalent COVID-19 vaccines, including XBB.1.5 Omicron SARS-CoV-2, are recommended for both primary and booster vaccinations against COVID-19. Monovalent vaccines, including only original SARS-CoV-2 strain, and bivalent vaccines, including original virus plus BA4/5 variant, are no longer recommended against COVID-19. Booster vaccination with XBB.1.5 containing vaccine should be prioritized for patients at high risk for severe COVID-19. Bacillus Calmette-Guérin (BCG) vaccination does not seem to be effective in preventing COVID-19. At the current phase of the pandemic, nirmatrelvir/ritonavir, remdesivir, molnupiravir, sotrovimab (for patients from XBB.1.5 variant dominant settings), and convalescent plasma can be considered for the treatment of high-risk early-stage outpatients with COVID-19, while hospitalized patients with more severe disease can be treated with dexamethasone, anti cytokines including tocilizumab, sarilumab, baricitinib, and tofacitinib and antithrombotic agents including enoxaparin. Remdesivir oral analogues and ensitrelvir fumarate are promising agents for treating acute COVID-19, which are in phase trials now; however, ivermectin, fluvoxamine, and metformin were shown to be ineffective.

Early oral nutritional supplement improves COVID-19 outcomes among hospitalized older patients during the Omicron wave

OBJECTIVES

The effect of and optimal timing for initiating an oral nutritional supplement(ONS) in hospitalized older patients with the Omicron variant infection remain unclear. The aim of this study was to explore the associations between the ONS and clinical outcomes.

METHODS

This study used a retrospective cohort design as primary analysis and a case-control design as sensitivity analysis. We collected data from patients with confirmed coronavirus disease 2019 (COVID-19) between April 2022 and June 2022 at Shanghai Fourth People's Hospital, one of the designated medical centers for COVID-19 in Shanghai, China. Patients were identified as ONS users or non-ONS users, with the former defined as early ONS (ONS initiated within 48 h from hospital admission), and late ONS (ONS initiated after 48 h) users.

RESULTS

The study included 1181 hospitalized patients ≥60 y of age. The mean age of the cohort was 78 y, and most patients were women (57.7%). Mortalities after propensity-score matching were 1.2% and 4.3% in the ONS group and non-ONS groups, respectively (P = 0.032). Subgroup analysis results showed that median (IQR) hospital length of stay and the median (IQR) length from symptom onset to viral clearance were shorter for the early ONS than for the late ONS group (9 [6-13] d versus 14 [11 -18] d; P < 0.001, and 11 [8-17] d versus 17 [13-22] d; P < 0.001, respectively). The findings from the case-control analysis supported those from the primary analysis.

CONCLUSIONS

Early ONS might have significantly lowered risk for in-hospital death, as well as reduce hospital length of stay and days of viral clearance in older patients with COVID-19 during the Omicron wave.

Three to four mRNA COVID-19 vaccines in multiple sclerosis patients on immunosuppressive drugs: Seroconversion and variant neutralization

BACKGROUND AND PURPOSE

An enhanced severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine regimen could improve humoral vaccine response in patients with multiple sclerosis (MS) treated by anti-CD20. The aim was to evaluate the serological response and the neutralizing activity after BNT162b2 primary and booster vaccination in MS patients, including patients on anti-CD20 receiving a primary vaccine regimen enhanced with three injections.

METHODS

In this prospective longitudinal cohort study of 90 patients (47 on anti-CD20, 10 on fingolimod, 33 on natalizumab, dimethylfumarate or teriflunomide), anti-SARS-CoV-2 receptor binding domain (RBD) immunoglobulin G antibodies were quantified and their neutralization capacity was evaluated by enzyme-linked immunosorbent assay (GenScript) and a virus neutralization test against B.1 historical strain, Delta and Omicron variants, before and after three to four BNT162b2 injections.

RESULTS

After the primary vaccination scheme, the anti-RBD positivity rate was strongly decreased in patients on anti-CD20 (28% [15%; 44%] after two shots, 45% [29%; 62%] after three shots) and fingolimod (50% [16%; 84%]) compared to other treatments (100% [90%; 100%]). Neutralization activity was also decreased in patients on anti-CD20 and fingolimod, and notably low for the Omicron variant in all patients (0%-22%). Delayed booster vaccination was performed in 54 patients, leading to a mild increase of anti-RBD seropositivity in patients on anti-CD20 although it was still lower compared to other treatments (65% [43%; 84%] vs. 100% [87%; 100%] respectively). After a booster, Omicron neutralization activity remained low on anti-CD20 and fingolimod treated patients but was strongly increased in patients on other treatments (91% [72%; 99%]).

DISCUSSION

In MS patients on anti-CD20, an enhanced primary vaccination scheme moderately increased anti-RBD seropositivity and anti-RBD antibody titre, but neutralization activity remained modest even after a fourth booster injection.

TRIAL REGISTRATION INFORMATION

COVIVAC-ID, NCT04844489, first patient included on 20 April 2021.

Effectiveness of oral antiviral agents on long-term cardiovascular risk in nonhospitalized patients with COVID-19: A multicenter matched cohort study

Although a novel oral antiviral agent can improve short-term COVID-19 outcomes, its effects on the long-term outcomes, namely the risk of major adverse cardiovascular events (MACEs), remains unknown. This retrospective cohort study used the TriNetX research network to identify nonhospitalized adult patients with COVID-19 between March 1, 2020, and January 1, 2022. A propensity score matching method was used to form two matched cohorts with and without receiving nirmatrelvir-ritonavir (NMV-r) or molnupiravir. The primary outcome was the incidence of MACEs within a 30-day to 1-year period following a diagnosis of COVID-19. Two cohorts of each 80 888 patients with balanced baseline characteristics were formed using propensity score matching. During the follow-up period, 976 patients in the study group and 1609 patients in the control group developed MACE. Overall, the study group had a significantly lower risk of MACE than the control group (hazard ratio [HR], 0.683; 95% confidence interval: 0.630-0.739). The significantly lower HRs of overall MACEs were consistently observed in most subgroup analyses (age: >41-≤64 years: 0.60 [0.52-0.89]; age: ≥65 years: 0.68 [0.62-0.76]; women: 0.63 [0.57-0.71]; men: 0.62 [0.55-0.70]; vaccinated: 0.74 [0.63-0.88]; unvaccinated: 0.66 [0.60-0.73]; NMV-r; 0.65 [0.59-0.71]; and molnupiravir: 0.75 [0.61-0.92]). In conclusion, novel oral antiviral agents, namely NMV-r and molnupiravir, were effective in reducing long-term MACEs among nonhospitalized patients with COVID-19, particularly when treated with NMV-r or in patients aged ≥40 years. These findings suggest the potential role of novel antiviral agents as a preventive measure to reduce further adverse cardiovascular outcomes.

Efficacy and Safety of Molnupiravir Treatment for COVID-19: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

INTRODUCTION

There are currently some differences in the research results of molnupiravir. This study aimed to evaluate the efficacy and safety of molnupiravir in the treatment of COVID-19.

METHODS

PubMed, Embase, CENTRAL (Cochrane Central Register of Controlled Trials), ClinicalTrials.gov, ICTRP (International Clinical Trials Registry Platform) and medRxiv were searched to identify relevant randomised controlled trials (RCTs) from inception to 1 January 2023. The Cochrane risk of bias tool for randomised trials was used to assess the bias risk of the included studies. Revman 5.4 software was used for meta-analysis.

RESULTS

Nine RCTs were included, including 31 573 COVID-19 patients, of whom 15 846 received molnupiravir. The meta-analysis results showed that the molnupiravir group had a higher proportion in terms of clinical improvement (Day 5 RR 2.41, 95% CI 1.18-4.92; Day 10 RR 1.45, 95% CI 1.04-2.01) and real-time polymerase chain reaction negativity (Day 5 RR 2.78, 95% CI 1.38-5.62; Day 10 RR 1.18, 95% CI 1.07-1.31). However, no significant difference was observed between the two groups in terms of mortality, hospitalisation, adverse events and serious adverse events.

CONCLUSIONS

Molnupiravir can accelerate the rehabilitation of COVID-19 patients, but it does not significantly reduce mortality and hospitalisation.

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.

Is Azvudine Comparable to Nirmatrelvir-Ritonavir in Real-World Efficacy and Safety for Hospitalized Patients with COVID-19? A Retrospective Cohort Study

INTRODUCTION

Azvudine and nirmatrelvir-ritonavir are more extensively used to treat COVID-19 in China due to their earlier approval by the National Medical Products Administration. However, there has been a scarcity of research directly comparing the clinical outcomes between azvudine and nirmatrelvir-ritonavir till now. We aimed to make a head-to-head comparison of the efficacy and safety of azvudine or nirmatrelvir-ritonavir in hospitalized patients with COVID-19 in China.

METHODS

This retrospective cohort study was conducted using data collected from Tongde Hospital of Zhejiang Province between December 2022 and January 2023. All-cause mortality, risk of progressing to a critical condition, proportion with nucleic-acid negative conversion (PNANC), time to first nucleic-acid negative conversion (TFNANC), length of hospital stay and incidence of adverse events were systematically assessed as outcomes. Multi-model regression analysis, propensity-score-matching analysis, subgroup analysis and several sensitivity analyses were applied to compare these outcomes.

RESULTS

This study included a total of 1571 hospitalized patients with COVID-19, among whom 272 received nirmatrelvir-ritonavir and 156 received azvudine. We found no significant differences in all-cause mortality (HR 1.41; 95% CI 0.56-3.56; P = 0.471), risk of progressing to critical COVID-19 (HR 1.67; 95% CI 0.78-3.60; P = 0.189), PNANC (HR 0.87; 95% CI 0.69-1.09; P = 0.220), length of stay (β - 0.82; 95% CI - 2.78 to 1.15; P = 0.414) and adverse event rate (3.21% vs. 4.41%, P = 0.538) between the two groups, although azvudine was slightly less effective than nirmatrelvir-ritonavir. Meanwhile, the azvudine group exhibited a significantly longer TFNANC (β 2.53; 95% CI 0.76-4.29; P = 0.005) than the nirmatrelvir-ritonavir group. Results were similar for propensity-score matching and multiple sensitivity analyses.

CONCLUSION

Azvudine probably possessed comparable efficacy and safety to nirmatrelvir-ritonavir, although it was less effective than nirmatrelvir-ritonavir for some outcomes.

Nirmatrelvir plus ritonavir remains effective in vaccinated patients at risk of progression with COVID-19: A systematic review and meta-analysis

Background

The efficacy of nirmatrelvir plus ritonavir (NMV-r) for vaccinated COVID-19 patients at high risk of progression is not adequately recognised. To address this gap, we conducted a systematic review and meta-analysis of current literature.

Methods

We searched PubMed, Web of Science, Embase, Cochrane Library, and medRxiv for articles published up to 8 January 2023 on NMV-r in outpatients. At least two researchers screened articles, extracted data, and assessed the quality of selected studies. We evaluated the results via risk ratios (RRs) with 95% confidence intervals (CIs) and tested for heterogeneity using I² statistics.

Results

We included seven observational cohort studies comprising 224 238 vaccinated patients. According to our meta-analysis, NMV-r reduced 47% incidence of all-cause death or hospitalisation within 30 days for vaccinated patients (RR = 0.53; 95% CI = 0.40-0.70; I² = 81%). After excluding the most influential result by sensitivity analysis, NMV-r still reduced risk of all-cause death or hospitalisation by 38% (RR = 0.62; 95% CI = 0.56-0.69; I² = 0%). In our secondary outcome, NMV-r also showed its benefits in reducing all-cause death in vaccinated patients (RR = 0.40; 95% CI = 0.19-0.85; I² = 23%).

Conclusions

We found positive evidence for the use of NMV-r for vaccinated patients at high-risk of progression with mild to moderate COVID-19. However, large-scale RCTs are needed to confirm these findings.

Registration

PROSPERO CRD42023391349.

A retrospective study of Reyanning mixture in elderly patients infected with SARS-CoV-2 Omicron variant

Objective: Reyanning mixture has been demonstrated to be effective in treating infected patients during the outbreak pandemic of SARS-CoV-2 Omicron variant of Coronavirus disease 2019 (COVID-19) in Shanghai 2022. The aim of this study is to further investigate the role of Reyanning mixture specifically in the treatment of elderly patients. Methods: This study enrolled 1,102 elderly patients who were infected with SARS-CoV-2 Omicron variant. Of these, 291 patients received Reyanning mixture in conjunction with conventional Western medicine treatment were assigned to the treatment group, while 811 patients only received conventional Western medicine treatment were assigned to the control group. Clinical parameters including hospitalization duration, viral shedding time, and Cycle Threshold (Ct) values of novel coronavirus nucleic acid tests, as well as adverse events were recorded and analyzed in both groups. Results: There was no significant difference in baseline characteristics between two groups. In comparison to the control group, the treatment group demonstrated a substantial difference in hospitalization duration (median: 8 days vs. 10 days, HR: 0.638, 95% CI: 0.558-0.731, p < 0.001). The treatment group also showed a significantly shorter viral shedding time compared to the control group (median: 7 days vs. 8 days, HR: 0.754, 95% CI: 0.659-0.863, p < 0.001). Multivariate Cox proportional-hazards model analysis indicated that the use of Reyanning mixture was closely associated with a reduction in hospitalization duration (HR: 1.562, 95% CI: 1.364-1.789, p < 0.001) and viral shedding time (HR: 1.335, 95% CI: 1.166-1.528, p < 0.001). In addition, during the treatment process, no serious adverse event occurred in either group. Conclusion: The improvement of clinical parameters in the treatment group indicate a promising therapeutic benefit of Reyanning mixture for elderly patients infected with SARS-CoV-2 Omicron variant in the present study. Further investigations are required to validate this finding by examining the underlying mechanism and function of Reyanning mixture.

Your Outpatient has Coronavirus Disease 2019: What Are the Treatment Options in the Current Severe Acute Respiratory Syndrome Coronavirus 2 Variant Climate?

Mutations accumulated by novel Severe Acute Respiratory Syndrome Coronavirus 2 Omicron sublineages contribute to evasion of previously effective monoclonal antibodies for treatment or prevention of Coronavirus Disease 2019 (COVID-19). Other authorized or approved antiviral drugs such as nirmatrelvir/ritonavir, remdesivir, and molnupiravir are, however, predicted to maintain activity against these sublineages and are key tools to reduce severe COVID-19 outcomes in vulnerable populations. A stepwise approach may be taken to target the appropriate antiviral drug to the appropriate patient, beginning with identifying whether a patient is at high risk for hospitalization or other complications of COVID-19. Among higher risk individuals, patient profile (including factors such as age, organ function, and comedications) and antiviral drug access inform suitable antiviral drug selection. When applied in targeted fashion, these therapies serve as a complement to vital ongoing nonpharmaceutical interventions and vaccination strategies that reduce morbidity and maximize protection against COVID-19.

Effectiveness of nirmatrelvir-ritonavir in preventing hospital admissions and deaths in people with COVID-19: a cohort study in a large US health-care system

BACKGROUND

In the USA, oral nirmatrelvir-ritonavir is authorised for use in patients aged 12 years or older with mild-to-moderate COVID-19 who are at risk of progression to severe disease and hospitalisation. We aimed to establish the effectiveness of nirmatrelvir-ritonavir in preventing hospital admissions and death in people with COVID-19 in an outpatient prescribing context in the USA.

METHODS

In this matched observational outpatient cohort study in the Kaiser Permanente Southern California (CA, USA) health-care system, data were extracted from electronic health records of non-hospitalised patients aged 12 years or older who received a positive SARS-CoV-2 PCR test result (their index test) between April 8 and Oct 7, 2022, and had not received another positive test result within the preceding 90 days. We compared outcomes between people who received nirmatrelvir-ritonavir and those who did not receive nirmatrelvir-ritonavir by matching cases by date, age, sex, clinical status (including care received, the presence or absence of acute COVID-19 symptoms at testing, and time from symptom onset to testing), vaccination history, comorbidities, health-care seeking during the previous year, and BMI. Our primary endpoint was the estimated effectiveness of nirmatrelvir-ritonavir in preventing hospital admissions or death within 30 days of a positive test for SARS-CoV-2.

FINDINGS

7274 nirmatrelvir-ritonavir recipients and 126 152 non-recipients with positive SARS-CoV-2 tests were included in our study. 5472 (75·2%) treatment recipients and 84 657 (67·1%) non-recipients were tested within 5 days of symptom onset. Nirmatrelvir-ritonavir had an overall estimated effectiveness of 53·6% (95% CI 6·6-77·0) in preventing hospital admission or death within 30 days of a positive test for SARS-CoV-2, which increased to 79·6% (33·9-93·8) when nirmatrelvir-ritonavir was dispensed within 5 days of symptom onset. Within the subgroup of patients tested within 5 days of symptom onset and whose treatment was dispensed on the day of their test, the estimated effectiveness of nirmatrelvir-ritonavir was 89·6% (50·2-97·8).

INTERPRETATION

In a setting with high levels of COVID-19 vaccine uptake, nirmatrelvir-ritonavir effectively reduced the risk of hospital admission or death within 30 days of a positive outpatient SARS-CoV-2 test.

FUNDING

US Centers for Disease Control and Prevention and US National Institutes of Health.

Antiviral Activity Against SARS-CoV-2 Variants Using in Silico and in Vitro Approaches

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emergence in 2019 led to global health crises and the persistent risk of viral mutations. To combat SARS-CoV-2 variants, researchers have explored new approaches to identifying potential targets for coronaviruses. This study aimed to identify SARS-CoV-2 inhibitors using drug repurposing. In silico studies and network pharmacology were conducted to validate targets and coronavirus-associated diseases to select potential candidates, and in vitro assays were performed to evaluate the antiviral effects of the candidate drugs to elucidate the mechanisms of the viruses at the molecular level and determine the effective antiviral drugs for them. Plaque and cytopathic effect reduction were evaluated, and real-time quantitative reverse transcription was used to evaluate the antiviral activity of the candidate drugs against SARS-CoV-2 variants in vitro. Finally, a comparison was made between the molecular docking binding affinities of fenofibrate and remdesivir (positive control) to conventional and identified targets validated from protein-protein interaction (PPI). Seven candidate drugs were obtained based on the biological targets of the coronavirus, and potential targets were identified by constructing complex disease targets and PPI networks. Among the candidates, fenofibrate exhibited the strongest inhibition effect 1 h after Vero E6 cell infection with SARS-CoV-2 variants. This study identified potential targets for coronavirus disease (COVID-19) and SARS-CoV-2 and suggested fenofibrate as a potential therapy for COVID-19.

Expert Consensus: Main Risk Factors for Poor Prognosis in COVID-19 and the Implications for Targeted Measures against SARS-CoV-2

The clinical evolution of patients infected with the Severe Acute Respiratory Coronavirus type 2 (SARS-CoV-2) depends on the complex interplay between viral and host factors. The evolution to less aggressive but better-transmitted viral variants, and the presence of immune memory responses in a growing number of vaccinated and/or virus-exposed individuals, has caused the pandemic to slowly wane in virulence. However, there are still patients with risk factors or comorbidities that put them at risk of poor outcomes in the event of having the coronavirus infectious disease 2019 (COVID-19). Among the different treatment options for patients with COVID-19, virus-targeted measures include antiviral drugs or monoclonal antibodies that may be provided in the early days of infection. The present expert consensus is based on a review of all the literature published between 1 July 2021 and 15 February 2022 that was carried out to establish the characteristics of patients, in terms of presence of risk factors or comorbidities, that may make them candidates for receiving any of the virus-targeted measures available in order to prevent a fatal outcome, such as severe disease or death. A total of 119 studies were included from the review of the literature and 159 were from the additional independent review carried out by the panelists a posteriori. Conditions found related to strong recommendation of the use of virus-targeted measures in the first days of COVID-19 were age above 80 years, or above 65 years with another risk factor; antineoplastic chemotherapy or active malignancy; HIV infection with CD4+ cell counts < 200/mm³; and treatment with anti-CD20 immunosuppressive drugs. There is also a strong recommendation against using the studied interventions in HIV-infected patients with a CD4+ nadir <200/mm³ or treatment with other immunosuppressants. Indications of therapies against SARS-CoV-2, regardless of vaccination status or history of infection, may still exist for some populations, even after COVID-19 has been declared to no longer be a global health emergency by the WHO.

Mercapto-pyrimidines are reversible covalent inhibitors of the papain-like protease (PLpro) and inhibit SARS-CoV-2 (SCoV-2) replication

The papain-like protease (PLpro) plays a critical role in SARS-CoV-2 (SCoV-2) pathogenesis and is essential for viral replication and for allowing the virus to evade the host immune response. Inhibitors of PLpro have great therapeutic potential, however, developing them has been challenging due to PLpro's restricted substrate binding pocket. In this report, we screened a 115 000-compound library for PLpro inhibitors and identified a new pharmacophore, based on a mercapto-pyrimidine fragment that is a reversible covalent inhibitor (RCI) of PLpro and inhibits viral replication in cells. Compound 5 had an IC50 of 5.1 μM for PLpro inhibition and hit optimization yielded a derivative with increased potency (IC50 0.85 μM, 6-fold higher). Activity based profiling of compound 5 demonstrated that it reacts with PLpro cysteines. We show here that compound 5 represents a new class of RCIs, which undergo an addition elimination reaction with cysteines in their target proteins. We further show that their reversibility is catalyzed by exogenous thiols and is dependent on the size of the incoming thiol. In contrast, traditional RCIs are all based upon the Michael addition reaction mechanism and their reversibility is base-catalyzed. We identify a new class of RCIs that introduces a more reactive warhead with a pronounced selectivity profile based on thiol ligand size. This could allow the expansion of RCI modality use towards a larger group of proteins important for human disease.

Viral burden rebound in hospitalised patients with COVID-19 receiving oral antivirals in Hong Kong: a population-wide retrospective cohort study

BACKGROUND

Viral rebound after nirmatrelvir-ritonavir treatment has implications for the clinical management and isolation of patients with COVID-19. We evaluated an unselected, population-wide cohort to identify the incidence of viral burden rebound and associated risk factors and clinical outcomes.

METHODS

We did a retrospective cohort study of hospitalised patients with a confirmed diagnosis of COVID-19 in Hong Kong, China, for an observation period from Feb 26 to July 3, 2022 (during the omicron BA.2.2 variant wave). Adult patients (age ≥18 years) admitted 3 days before or after a positive COVID-19 test were selected from medical records held by the Hospital Authority of Hong Kong. We included patients with non-oxygen-dependent COVID-19 at baseline receiving either molnupiravir (800 mg twice a day for 5 days), nirmatrelvir-ritonavir (nirmatrelvir 300 mg with ritonavir 100 mg twice a day for 5 days), or no oral antiviral treatment (control group). Viral burden rebound was defined as a reduction in cycle threshold (Ct) value (≥3) on quantitative RT-PCR test between two consecutive measurements, with such decrease sustained in an immediately subsequent Ct measurement (for those patients with ≥3 Ct measurements). Logistic regression models were used to identify prognostic factors for viral burden rebound, and to assess associations between viral burden rebound and a composite clinical outcome of mortality, intensive care unit admission, and invasive mechanical ventilation initiation, stratified by treatment group.

FINDINGS

We included 4592 hospitalised patients with non-oxygen-dependent COVID-19 (1998 [43·5%] women and 2594 [56·5%] men). During the omicron BA.2.2 wave, viral burden rebound occurred in 16 of 242 patients (6·6% [95% CI 4·1-10·5]) receiving nirmatrelvir-ritonavir, 27 of 563 (4·8% [3·3-6·9]) receiving molnupiravir, and 170 of 3787 (4·5% [3·9-5·2]) in the control group. The incidence of viral burden rebound did not differ significantly across the three groups. Immunocompromised status was associated with increased odds of viral burden rebound, regardless of antiviral treatment (nirmatrelvir-ritonavir: odds ratio [OR] 7·37 [95% CI 2·56-21·26], p=0·0002; molnupiravir: 3·05 [1·28-7·25], p=0·012; control: 2·21 [1·50-3·27], p<0·0001). Among patients receiving nirmatrelvir-ritonavir, the odds of viral burden rebound were higher in those aged 18-65 years (vs >65 years; 3·09 [1·00-9·53], p=0·050), those with high comorbidity burden (score >6 on the Charlson Comorbidity Index; 6·02 [2·09-17·38], p=0·0009), and those concomitantly taking corticosteroids (7·51 [1·67-33·82], p=0·0086); whereas the odds were lower in those who were not fully vaccinated (0·16 [0·04-0·67], p=0·012). In patients receiving molnupiravir, those aged 18-65 years (2·68 [1·09-6·58], p=0·032) or on concomitant corticosteroids (3·11 [1·23-7·82], p=0·016) had increased odds of viral burden rebound. We found no association between viral burden rebound and occurrence of the composite clinical outcome from day 5 of follow-up (nirmatrelvir-ritonavir: adjusted OR 1·90 [0·48-7·59], p=0·36; molnupiravir: 1·05 [0·39-2·84], p=0·92; control: 1·27 [0·89-1·80], p=0·18).

INTERPRETATION

Viral burden rebound rates are similar between patients with antiviral treatment and those without. Importantly, viral burden rebound was not associated with adverse clinical outcomes.

FUNDING

Health and Medical Research Fund, Health Bureau, The Government of the Hong Kong Special Administrative Region, China.

TRANSLATION

For the Chinese translation of the abstract see Supplementary Materials section.

Clinical effectiveness of oral antiviral agents in older patients with COVID-19 based on real-world data

Several randomized controlled trials and real-world cohort studies have demonstrated the efficacies of nirmatrelvir plus ritonavir (NMV-r) and molnupiravir (MOV) in at-risk patients with COVID-19; however, the effectiveness of antisevere acute respiratory syndrome-coronavirus 2 treatments on older patients (≥65 years) remains unclear. This retrospective cohort study aimed to assess the clinical effectiveness of the oral antiviral agents, MOV and NMV-r, in older patients (≥65 years) infected with severe acute respiratory syndrome-coronavirus 2. Nonhospitalized older patients with COVID-19 between January 1, 2022, and December 31, 2022, were recruited from the TriNetX Research Network. Propensity score matching (PSM) was used to match patients who received either NMV-r or MOV treatment with those who did not receive any oral antiviral agents. Hazard ratios (HRs) for composite all-cause hospitalization or death during the 30-day follow-up period were calculated. PSM revealed two cohorts with 28 824 patients each having balanced baseline characteristics. The antiviral group was associated with significantly lower risk of the primary composite outcome of all-cause hospitalization or death than the control group (241 vs. 801; HR, 0.307; 95% confidence interval (CI), 0.27-0.36) during the follow-up period. For the secondary outcome, the antiviral group had a significantly lower risk of all-cause hospitalization (288 vs. 725; HR, 0.322; 95% CI, 0.28-0.37) and mortality (16 vs. 94; HR, 0.176; 95% CI, 0.10-0.30) than the control group. Moreover, the reduced risk of all-cause hospitalization or death remained consistent in patients receiving NMV-r (HR, 0.279; 95% CI, 0.24-0.33) and MOV (HR, 0.279; 95% CI, 0.21-0.38). Our results revealed that NMV-r and MOV decreased the all-cause hospitalization and death rates among older patients with COVID-19, supporting the use of antivirals in this vulnerable population.

Effectiveness of COVID-19 Treatment With Nirmatrelvir-Ritonavir or Molnupiravir Among U.S. Veterans: Target Trial Emulation Studies With One-Month and Six-Month Outcomes

BACKGROUND

Information about the effectiveness of oral antivirals in preventing short- and long-term COVID-19-related outcomes in the setting of Omicron variant transmission and COVID-19 vaccination is limited.

OBJECTIVE

To measure the effectiveness of nirmatrelvir-ritonavir and molnupiravir for outpatient treatment of COVID-19.

DESIGN

Three retrospective target trial emulation studies comparing matched cohorts of nirmatrelvir-ritonavir versus no treatment, molnupiravir versus no treatment, and nirmatrelvir-ritonavir versus molnupiravir.

SETTING

Veterans Health Administration (VHA).

PARTICIPANTS

Nonhospitalized veterans in VHA care who were at risk for severe COVID-19 and tested positive for SARS-CoV-2 during January through July 2022.

INTERVENTION

Nirmatrelvir-ritonavir or molnupiravir pharmacotherapy.

MEASUREMENTS

Incidence of any hospitalization or all-cause mortality at 30 days and from 31 to 180 days.

RESULTS

Eighty-seven percent of participants were male; the median age was 66 years, and 18% were unvaccinated. Compared with matched untreated control participants, those treated with nirmatrelvir-ritonavir (n = 9607) had lower 30-day risk for hospitalization (22.07 vs. 30.32 per 1000 participants; risk difference [RD], -8.25 [95% CI, -12.27 to -4.23] per 1000 participants) and death (1.25 vs. 5.47 per 1000 participants; RD, -4.22 [CI, -5.45 to -3.00] per 1000 participants). Among persons alive at day 31, reductions were seen in 31- to 180-day incidence of death (hazard ratio, 0.66 [CI, 0.49 to 0.89]) but not hospitalization (subhazard ratio, 0.90 [CI, 0.79 to 1.02]). Molnupiravir-treated participants (n = 3504) had lower 30-day and 31- to 180-day risks for death (3.14 vs. 13.56 per 1000 participants at 30 days; RD, -10.42 [CI, -13.49 to -7.35] per 1000 participants; hazard ratio at 31 to 180 days, 0.67 [CI, 0.48 to 0.95]) but not hospitalization. A difference in 30-day or 31- to 180-day risk for hospitalization or death was not observed between matched nirmatrelvir- or molnupiravir-treated participants.

LIMITATION

The date of COVID-19 symptom onset for most veterans was unknown.

CONCLUSION

Nirmatrelvir-ritonavir was effective in reducing 30-day hospitalization and death. Molnupiravir was associated with a benefit for 30-day mortality but not hospitalization. Further reductions in mortality from 31 to 180 days were observed with both antivirals.

PRIMARY FUNDING SOURCE

U.S. Department of Veterans Affairs.

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.

An explanation for SARS-CoV-2 rebound after Paxlovid treatment

In a fraction of SARS-CoV-2 infected individuals treated with the oral antiviral Paxlovid, the virus rebounds following treatment. The mechanism driving rebound is not understood. Here, we show that viral dynamic models based on the hypothesis that Paxlovid treatment near the time of symptom onset halts the depletion of target cells, but may not fully eliminate the virus, which can lead to viral rebound. We also show that the occurrence of viral rebound is sensitive to model parameters, and the time treatment is initiated, which may explain why only a fraction of individuals develop viral rebound. Finally, the models are used to test the therapeutic effects of two alternative treatment schemes. These findings also provide a possible explanation for rebounds following other antiviral treatments for SARS-CoV-2.

Long-term post-acute sequelae of COVID-19 infection: a retrospective, multi-database cohort study in Hong Kong and the UK

Background

Evidence on post-acute sequelae of SARS-CoV-2 (PASC) has shown inconsistent findings. This study aimed to generate coherent evidence on the post-acute sequelae of COVID-19 infection using electronic healthcare records across two regions.

Methods

In this retrospective, multi-database cohort study, patients with COVID-19 aged 18 or above between April 1st 2020 and May 31st 2022 from the Hong Kong Hospital Authority (HKHA) and March 16th 2020 and May 31st 2021 from the UK Biobank (UKB) databases and their matched controls were followed for up to 28 and 17 months, respectively. Covariates between patients with COVID-19 and non-COVID-19 controls were adjusted using propensity score-based inverse probability treatment weighting. Cox proportional regression was used to estimate the hazard ratio (HR) of clinical sequelae, cardiovascular, and all-cause mortality 21 days after COVID-19 infection.

Findings

A total of 535,186 and 16,400 patients were diagnosed with COVID-19 from HKHA and UKB, of whom 253,872 (47.4%) and 7613 (46.4%) were male, with a mean age (±SD) of 53.6 (17.8) years and 65.0 (8.5) years, respectively. Patients with COVID-19 incurred greater risk of heart failure (HR 1.82; 95% CI 1.65, 2.01), atrial fibrillation (1.31; 1.16, 1.48), coronary artery disease (1.32; 1.07, 1.63), deep vein thrombosis (1.74; 1.27, 2.37), chronic pulmonary disease (1.61; 1.40, 1.85), acute respiratory distress syndrome (1.89; 1.04, 3.43), interstitial lung disease (3.91; 2.36, 6.50), seizure (2.32; 1.12, 4.79), anxiety disorder (1.65; 1.29, 2.09), post-traumatic stress disorder (1.52; 1.23, 1.87), end-stage renal disease (1.76; 1.31, 2.38), acute kidney injury (2.14; 1.69, 2.71), pancreatitis (1.42; 1.10, 1.83), cardiovascular (2.86; 1.25, 6.51) and all-cause mortality (4.16; 2.11, 8.21) mortality during their post-acute phase of infection.

Interpretation

The consistent greater risk of PASC highlighted the need for sustained multi-disciplinary care for COVID-19 survivors.

Funding

Health Bureau, The Government of the Hong Kong Special Administrative Region, Collaborative Research Fund, The Government of the Hong Kong Special Administrative Region and AIR@InnoHK, administered by the Innovation and Technology Commission, The Government of the Hong Kong Special Administrative Region.

Comparative efficacy and safety of nirmatrelvir/ritonavir and molnupiravir for COVID-19: A systematic review and meta-analysis

This study aimed to compare the efficacy and safety of nirmatrelvir/ritonavir (Paxlovid) with molnupiravir in the treatment of coronavirus disease 2019 (COVID-19). To end this, PubMed, Cochrane Library, Web of Science, medRxiv, and Google Scholar were systematically searched to collect relevant evidence up to February 15, 2023. The risk of bias was evaluated using the risk of bias in nonrandomized studies of interventions tool. Data were analyzed using Comprehensive Meta-Analysis software. Eighteen studies involving 57 659 patients were included in the meta-analysis. The meta-analysis showed a significant difference between nirmatrelvir/ritonavir and molnupiravir in terms of all-cause mortality rate (odds ratio [OR] = 0.54, 95% confidence interval [CI]: 0.44-0.67), all-cause hospitalization rate (OR = 0.61, 95% CI: 0.54-0.69), death or hospitalization rate (OR = 0.61, 95% CI: 0.38-0.99), and negative polymerase chain reaction conversion time (mean difference = -1.55, 95% CI: -1.74 to -1.37). However, no significant difference was observed between the two groups in terms of COVID-19 rebound (OR = 0.87, 95% CI: 0.71-1.07). In terms of safety, although the incidence of any adverse events was higher in the nirmatrelvir/ritonavir group (OR = 2.52, 95% CI: 1.57-4.06), no significant difference was observed between the two treatments in terms of adverse events leading to treatment discontinuation (OR = 1.18, 95% CI: 0.69-2.00). The present meta-analysis demonstrated the significant superiority of nirmatrelvir/ritonavir over molnupiravir in improving clinical efficacy in COVID-19 patients during the prevalence of Omicron variant. These findings, however, need to be further confirmed.

Association of Molnupiravir and Nirmatrelvir-Ritonavir with reduced mortality and sepsis in hospitalized omicron patients: a territory-wide study

This study evaluates the association between antivirals (Molnupiravir and Nirmatrelvir-Ritonavir) and all-cause and respiratory mortality and organ dysfunction among high-risk COVID-19 patients during an Omicron outbreak. Two cohorts, Nirmatrelvir-Ritonavir versus control and Molnupiravir versus control, were constructed with inverse probability treatment weighting to balance baseline characteristics. Cox proportional hazards models evaluated the association of their use with all-cause mortality, respiratory mortality, and all-cause sepsis (a composite of circulatory shock, respiratory failure, acute liver injury, coagulopathy, and acute liver impairment). Patients recruited were hospitalized and diagnosed with the COVID-19 Omicron variant between February 22, 2022 and April 15, 2022, and followed up until May 15, 2022. The study included 17,704 patients. There were 4.67 and 22.7 total mortalities per 1000 person-days in the Nirmatrelvir-Ritonavir and control groups respectively before adjustment (weighted incidence rate ratio, - 18.1 [95% CI - 23.0 to - 13.2]; hazard ratio, 0.18 [95% CI, 0.11-0.29]). There were 6.64 and 25.9 total mortalities per 1000 person-days in the Molnupiravir and control groups respectively before adjustment (weighted incidence rate ratio per 1000 person-days, - 19.3 [95% CI - 22.6 to - 15.9]; hazard ratio, 0.23 [95% CI 0.18-0.30]). In all-cause sepsis, there were 13.7 and 35.4 organ dysfunction events per 1000 person-days in the Nirmatrelvir-Ritonavir and control groups respectively before adjustment (weighted incidence rate ratio per 1000 person-days, - 21.7 [95% CI - 26.3 to - 17.1]; hazard ratio, 0.44 [95% CI 0.38-0.52]). There were 23.7 and 40.8 organ dysfunction events in the Molnupiravir and control groups respectively before adjustment (weighted incidence ratio per 1000 person-days, - 17.1 [95% CI, - 20.6 to - 13.6]; hazard ratio, 0.63 [95% CI 0.58-0.69]). Among COVID-19 hospitalized patients, use of either Nirmatrelvir-Ritonavir or Molnupiravir compared with no antiviral use was associated with a significantly lower incidence of 28-days all-cause and respiratory mortality and sepsis.

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.

Effectiveness of nirmatrelvir plus ritonavir treatment for patients with chronic lymphocytic leukemia during the Omicron surge

Patients with chronic lymphoid leukemia (CLL), even in the Omicron era and after vaccination, suffer from persistent COVID-19 infection, higher complications, and mortality compared with the general population. In this study, we evaluated retrospectively the effectiveness of nirmatrelvir + ritonavir among 1080 patients with CLL who were infected with severe acute respiratory syndrome coronavirus 2. Nirmatrelvir administration was associated with a reduction in COVID-19-related hospitalization or death by day 35. Specifically, the rate of COVID-19-related hospitalization or death in the treated group compared with the untreated group was 4.8% (14 out of 292) vs 10.2% (75 out of 733), respectively. Moreover, we report a 69% relative risk reduction in COVID-19-related hospitalization or death in patients with CLL at the age of ≥65 years. Multivariate analysis indicates that patients aged >65 years, patients who received heavy treatment (>2 previous treatments), patients with recent hospitalizations, intravenous immunoglobulin (IVIG) treatment, and comorbidity had significant improvement outcomes after treatment with nirmatrelvir.

Management of patients with multiple myeloma and COVID-19 in the post pandemic era: a consensus paper from the European Myeloma Network (EMN)

In the post-pandemic COVID-19 period, human activities have returned to normal and COVID-19 cases are usually mild. However, patients with multiple myeloma (MM) present an increased risk for breakthrough infections and severe COVID-19 outcomes, including hospitalization and death. The European Myeloma Network has provided an expert consensus to guide patient management in this era. Vaccination with variant-specific booster vaccines, such as the bivalent vaccine for the ancestral Wuhan strain and the Omicron BA.4/5 strains, is essential as novel strains emerge and become dominant in the community. Boosters should be administered every 6-12 months after the last vaccine shot or documented COVID-19 infection (hybrid immunity). Booster shots seem to overcome the negative effect of anti-CD38 monoclonal antibodies on humoral responses; however, anti-BCMA treatment remains an adverse predictive factor for humoral immune response. Evaluation of the immune response after vaccination may identify a particularly vulnerable subset of patients who may need additional boosters, prophylactic therapies and prevention measures. Pre-exposure prophylaxis with tixagevimab/cilgavimab is not effective against the new dominant variants and thus is no longer recommended. Oral antivirals (nirmatrelvir/ritonavir and molnupiravir) and remdesivir are effective against Omicron subvariants BA.2.12.1, BA.4, BA.5, BQ.1.1 and/or XBB.1.5 and should be administered in MM patients at the time of a positive COVID-19 test or within 5 days post symptoms onset. Convalescent plasma seems to have low value in the post-pandemic era. Prevention measures during SARS-CoV-2 outbreaks, including mask wearing and avoiding crowded places, seem prudent to continue for MM patients.

Drug treatment of COVID-19 infection

PURPOSE OF REVIEW

COVID-19 pandemic has caused more than 6.6 million deaths globally. Tremendous efforts have been committed for the development of new and repurposed drugs for the treatment of COVID-19. Although different international and national guidelines share consensus in the management of COVID-19 disease with different levels of severity, new challenges have emerged, steering the need for ongoing research in advancing the clinical management of COVID-19.

RECENT FINDINGS

This review focuses on recent data from randomized trials and postmarketing real-world evidence for the treatment of mild to moderate disease in the outpatient setting and patients hospitalized for COVID-19 with varying level of severity. Relevant data for treatment of the latest omicron sub-variants in people who received vaccination are presented. Challenges in special populations, including immunocompromised hosts, patients with renal failure and pregnant women, are also discussed.

SUMMARY

Treatment of COVID-19 should be personalized according to host characteristics, degree of severity and available treatment options.

Vaccines and therapeutics for immunocompromised patients with COVID-19

The COVID-19 pandemic has disproportionately impacted immunocompromised patients. This diverse group is at increased risk for impaired vaccine responses, progression to severe disease, prolonged hospitalizations and deaths. At particular risk are people with deficiencies in lymphocyte number or function such as transplant recipients and those with hematologic malignancies. Such patients' immune responses to vaccination and infection are frequently impaired leaving them more vulnerable to prolonged high viral loads and severe complications of COVID-19. Those in turn, have implications for disease progression and persistence, development of immune escape variants and transmission of infection. Data to guide vaccination and treatment approaches in immunocompromised people are generally lacking and extrapolated from other populations. The large clinical trials leading to authorisation and approval of SARS-CoV-2 vaccines and therapeutics included very few immunocompromised participants. While experience is accumulating, studies focused on the special circumstances of immunocompromised patients are needed to inform prevention and treatment approaches.

Oral Azvudine for hospitalised patients with COVID-19 and pre-existing conditions: a retrospective cohort study

Background

As the COVID-19 pandemic continues to spread, the number of associated deaths continues to increase, especially among those with pre-existing conditions. Azvudine is recommended as a priority treatment for patients with COVID-19, but its efficacy in patients with pre-existing conditions is unknown.

Methods

This is a single-centre, retrospective cohort study between December 5, 2022 and January 31, 2023 in Xiangya Hospital of Central South University in China to evaluate the clinical efficacy of Azvudine in hospitalised patients with COVID-19 and pre-existing conditions. Patients with Azvudine and controls were propensity score-matched (1:1) for age, gender, vaccination status, time from symptom onset to treatment exposure, severity at admission, concomitant treatments initiated at admission. The primary outcome was a composite outcome of disease progression, and the secondary outcome was each of these individual disease progression outcomes. The univariate Cox regression model was used to estimate a hazard ratio (HR) with 95% confidence interval (CI) for each result between the groups.

Findings

We identified 2118 hospitalised patients with COVID-19 during the study period, with a follow-up of up to 38 days. After exclusions and propensity score matching, we included 245 Azvudine recipients and 245 matched controls. Azvudine recipients had lower crude incidence rate of composite disease progression outcome compared with matched controls (7.125/1000 person-days vs. 16.004/1000 person-days, P = 0.018). There was no significant difference in all-cause death between these two groups (1.934/1000 person-days vs. 4.128/1000 person-days, P = 0.159). Azvudine treatment was associated with significantly lower risks of composite disease progression outcome compared with matched controls (HR: 0.49; 95% CI: 0.27-0.89, P = 0.016). A significant difference in all-cause death was not found (HR: 0.45; 95% CI: 0.15-1.36, P = 0.148).

Interpretation

These findings indicate that Azvudine therapy showed substantial clinical benefits in hospitalised patients with COVID-19 and pre-existing conditions, and should be considered for this population of patients.

Funding

This work was supported by the National Natural Science Foundation of China (Grant Nos. 82103183 to F. Z., 82102803, 82272849 to G. D.), National Natural Science Foundation of Hunan Province (Grant Nos. 2022JJ40767 to F. Z., 2021JJ40976 to G. D.), Huxiang Youth Talent Program (Grant Nos. 2022RC1014 to M.S.) and Ministry of Industry and Information Technology of China (Grant Nos. TC210804V to M.S.).

Efficacy of Molnupiravir for the Treatment of Mild or Moderate COVID-19 in Adults: A Meta-Analysis

The aim of this meta-analysis is to evaluate the efficacy of molnupiravir among mild or moderate COVID-19 patients. This meta-analysis was reported according to the guidelines of Preferred Reporting Items for Systematic Reviews and Meta-Analyses. Two authors independently performed a comprehensive search for relevant studies in PubMed, Cochrane Library, and Web of Science. The keywords used to search for relevant records were "Molnupiravir," "COVID-19," and "efficacy." This meta-analysis included studies that compared the effectiveness of molnupiravir with a placebo for COVID-19 treatment. The primary outcome assessed in this meta-analysis was the composite of hospitalization and all-cause mortality (30 days). In addition, we assessed all-cause mortality and hospitalization separately and the number of patients who tested negative for viral RNA on day five. A total of 10 studies were included in the meta-analysis. Among the 10 studies, five were randomized controlled trials and five were observational studies. Based on the results presented in the meta-analysis, it can be concluded that molnupiravir has a significant impact on reducing all-cause mortality and improving the proportion of patients who test negative for viral RNA on day five. The risk of hospitalization and composite outcome was also lower in molnupiravir-treated patients, although the difference was statistically insignificant. The subgroup analysis showed consistent results across all subgroups, indicating that the effect of molnupiravir is consistent regardless of patient characteristics.

Recent Advances in Covalent Drug Discovery

In spite of the increasing number of biologics license applications, the development of covalent inhibitors is still a growing field within drug discovery. The successful approval of some covalent protein kinase inhibitors, such as ibrutinib (BTK covalent inhibitor) and dacomitinib (EGFR covalent inhibitor), and the very recent discovery of covalent inhibitors for viral proteases, such as boceprevir, narlaprevir, and nirmatrelvir, represent a new milestone in covalent drug development. Generally, the formation of covalent bonds that target proteins can offer drugs diverse advantages in terms of target selectivity, drug resistance, and administration concentration. The most important factor for covalent inhibitors is the electrophile (warhead), which dictates selectivity, reactivity, and the type of protein binding (i.e., reversible or irreversible) and can be modified/optimized through rational designs. Furthermore, covalent inhibitors are becoming more and more common in proteolysis, targeting chimeras (PROTACs) for degrading proteins, including those that are currently considered to be 'undruggable'. The aim of this review is to highlight the current state of covalent inhibitor development, including a short historical overview and some examples of applications of PROTAC technologies and treatment of the SARS-CoV-2 virus.

Effectiveness, Tolerability and Prescribing Choice of Antiviral Molecules Molnupiravir, Remdesivir and Nirmatrelvir/r: A Real-World Comparison in the First Ten Months of Use

In 2022, three antiviral drugs-molnupiravir, remdesivir and nirmatrelvir/ritonavir-were introduced for treatment of mild-to-moderate COVID-19 in high-risk patients. The aim of this study is the evaluation of their effectiveness and tolerability in a real-life setting. A single-center observational study was set up, with the involvement of 1118 patients, with complete follow-up data, treated between the 5th of January and the 3rd of October 2022 at Santa Maria Goretti's hospital in Latina, Central Italy. A univariable and a multivariable analysis were performed on clinical and demographic data and composite outcome, the persistence of symptoms at 30 days and time to negativization, respectively. The three antivirals showed a similar effectiveness in containing the progression of the infection to severe COVID-19 and a good tolerability in the absence of serious adverse effects. Persistence of symptoms after 30 days was more common in females than males and less common in patients treated with molnupiravir and nirmatrelvir/r. The availability of different antiviral molecules is a strong tool and, if correctly prescribed, they can have a significant role in changing the natural history of infection for frail persons, in which vaccination could be not sufficient for the prevention of severe COVID-19.

The Antiviral Effect of Nirmatrelvir/Ritonavir during COVID-19 Pandemic Real-World Data

INTRODUCTION

Vaccination against SARS-CoV-2 and the prevalence of Omicron variants have reduced the risk of the severe clinical progress of COVID-19. However, the risk of breakthrough infections has increased, and early administration of an effective antiviral treatment is significant in order to prevent the severe progression of COVID-19 in vulnerable patients with comorbidities.

PATIENTS AND METHODS

Adults with confirmed SARS-CoV-2 infection were included in a matched-pair retrospective study based on age, gender, comorbidities and vaccination status. They were divided into two groups: group A (n = 200) consisted of outpatients at increased risk of severe clinical progress who were treated with nirmatrelvir/ritonavir and group B (n = 200) consisted of non-hospitalized patients who did not receive antiviral treatment. Demographic data, clinical outcome (death, intubation), days of hospitalization, time for recovery, adverse events and treatment compliance were reported.

RESULTS

The median age (75.24 ± 13.12 years in the study group and 76.91 ± 14.02 years in the comparison group) and the proportion of males (59% vs. 60.5%, respectively) were similar between the two groups. A total of 6.5% of patients in group A and 10.5% in group B were unvaccinated against SARS-CoV-2. Three patients from group A (1.5%) and one hundred eleven (55.5%) from group B required hospitalization. The duration of hospitalization (3 days vs. 10 days in group B, p < 0.001) and the total time needed for recovery (5 days vs. 9 days, p < 0.001) was shorter in the study group. A rebound of SARS-CoV-2 infection within 8-12 days after diagnosis was documented in 6.5% of patients in group A and 8% of patients in group B.

CONCLUSION

Oral treatment with nirmatrelvir/ritonavir in high-risk non-hospitalized patients was safe and effective in preventing the severe clinical progress of COVID-19 pneumonia. Early administration of antiviral agents in vulnerable outpatients combined with a full vaccination scheme is significant in order to avoid hospitalization and severe clinical outcomes.

Nirmatrelvir and risk of hospital admission or death in adults with covid-19: emulation of a randomized target trial using electronic health records

OBJECTIVE

To estimate the effectiveness of nirmatrelvir, compared with no treatment, in reducing admission to hospital or death at 30 days in people infected with the SARS-CoV-2 virus and at risk of developing severe disease, according to vaccination status and history of previous SARS-CoV-2 infection.

DESIGN

Emulation of a randomized target trial with electronic health records.

SETTING

Healthcare databases of the US Department of Veterans Affairs PARTICIPANTS: 256 288 participants with a SARS-CoV-2 positive test result and at least one risk factor for developing severe covid-19 disease, between 3 January and 30 November 2022. 31 524 were treated with nirmatrelvir within five days of testing positive for SARS-CoV-2 and 224 764 received no treatment.

MAIN OUTCOME MEASURES

The effectiveness of starting nirmatrelvir within five days of a positive SARS-CoV-2 test result versus no treatment in reducing the risk of admission to hospital or death at 30 days was estimated in those who were not vaccinated, in those who received one or two doses of vaccine, and those who received a vaccine booster and, separately, in participants with a primary SARS-CoV-2 infection or reinfection. The inverse probability weighting method was used to balance personal and health characteristics between the groups. Relative risk and absolute risk reduction were computed from cumulative incidence at 30 days, estimated by weighted Kaplan-Meier estimator.

RESULTS

Among people who were not vaccinated (n=76 763; 5338 nirmatrelvir and 71 425 no treatment), compared with no treatment, the relative risk of nirmatrelvir in reducing admission to hospital or death at 30 days was 0.60 (95% confidence interval 0.50 to 0.71); the absolute risk reduction was 1.83% (95% confidence interval 1.29% to 2.49%). The relative risk and absolute risk reduction, compared with no treatment, were 0.65 (0.57 to 0.74) and 1.27% (0.90% to 1.61%), respectively, in people who received one or two doses of vaccine (n=84 620; 7989 nirmatrelvir and 76 631 no treatment); 0.64 (0.58 to 0.71) and 1.05% (0.85% to 1.27%) in individuals who received a booster dose of vaccine (n=94 905; 18 197 nirmatrelvir and 76 708 no treatment); 0.61 (0.57 to 0.65) and 1.36% (1.19% to 1.53%) in participants with a primary SARS-CoV-2 infection (n=228 081; 26 350 nirmatrelvir and 201 731 no treatment); and 0.74 (0.63 to 0.87) and 0.79% (0.36% to 1.18%) in participants who were reinfected with the SARS-CoV-2 virus (n=28 207; 5174 nirmatrelvir and 23 033 no treatment). Nirmatrelvir was associated with a reduced risk of admission to hospital or death in those aged ≤65 years and > 65 years; in men and women; in black and white participants; in those with 1-2, 3-4, and ≥5 risk factors for progression to severe covid-19 illness; and in those infected during the omicron BA.1 or BA.2 predominant era, and the BA.5 predominant era.

CONCLUSIONS

In people with SARS-CoV-2 infection who were at risk of developing severe disease, compared with no treatment, nirmatrelvir was associated with a reduced risk of admission to hospital or death at 30 days in people who were not vaccinated, vaccinated, and had received a booster vaccine, and in those with a primary SARS-CoV-2 infection and reinfection.

Antiviral medications for mild-to-moderate COVID-19 in Japan: a gap of timing between clinical trials and real-world scenarios in a fast-changing pandemic

The rapid spread of a novel type of coronavirus infection, coronavirus disease 2019 (COVID-19) has made it difficult to implement the results of clinical trials in real-world situations. After the emergence of the Omicron variant and messenger RNA vaccine, a combination of less virulent but more contagious viruses and more people with protective immunity has resulted in a larger number of patients with less severe, mild-to-moderate COVID-19. Many patients with severe conditions did not have extensive viral pneumonia frequently seen in the "pre-Omicron" era but had serious complications due to aggravation of underlying comorbidities or secondary bacterial infections. Most clinical trials for new antiviral drugs were conducted in the "pre-Omicron" period based on a different set of background patient characteristics than the ones seen in the Omicron period. Understanding situational differences due to the gap in the timing between clinical trials and the practical use of drugs for COVID-19 will assist in developing an effective treatment strategy in real-world practice. In this seminar, we reviewed antiviral treatments for mild-to-moderate COVID-19 from the viewpoint of the difference in patient backgrounds between clinical trials and real-world studies, focusing on drugs currently used in Japan.

COVID-19 Therapeutics: An Update on Effective Treatments Against Infection With SARS-CoV-2 Variants

The coronavirus disease 2019 (COVID-19) pandemic is one of the most consequential global health crises in over a century. Since its discovery in 2019, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to mutate into different variants and sublineages, rendering previously potent treatments and vaccines ineffective. With significant strides in clinical and pharmaceutical research, different therapeutic strategies continue to be developed. The currently available treatments can be broadly classified based on their potential targets and molecular mechanisms. Antiviral agents function by disrupting different stages of SARS-CoV-2 infection, while immune-based treatments mainly act on the human inflammatory response responsible for disease severity. In this review, we discuss some of the current treatments for COVID-19, their mode of actions, and their efficacy against variants of concern. This review highlights the need to constantly evaluate COVID-19 treatment strategies to protect high risk populations and fill in the gaps left by vaccination.

Effectiveness of Molnupiravir and Nirmatrelvir-Ritonavir in Hospitalized Patients With COVID-19 : A Target Trial Emulation Study

BACKGROUND

Whether hospitalized patients benefit from COVID-19 oral antivirals is uncertain.

OBJECTIVE

To examine the real-world effectiveness of molnupiravir and nirmatrelvir-ritonavir in hospitalized patients with COVID-19 during the Omicron outbreak.

DESIGN

Target trial emulation study.

SETTING

Electronic health databases in Hong Kong.

PARTICIPANTS

The molnupiravir emulated trial included hospitalized patients with COVID-19 aged 18 years or older between 26 February and 18 July 2022 (n = 16 495). The nirmatrelvir-ritonavir emulated trial included hospitalized patients with COVID-19 aged 18 years or older between 16 March and 18 July 2022 (n = 7119).

INTERVENTION

Initiation of molnupiravir or nirmatrelvir-ritonavir within 5 days of hospitalization with COVID-19 versus no initiation of molnupiravir or nirmatrelvir-ritonavir.

MEASUREMENTS

Effectiveness against all-cause mortality, intensive care unit (ICU) admission, or use of ventilatory support within 28 days.

RESULTS

The use of oral antivirals in hospitalized patients with COVID-19 was associated with a lower risk for all-cause mortality (molnupiravir: hazard ratio [HR], 0.87 [95% CI, 0.81 to 0.93]; nirmatrelvir-ritonavir: HR, 0.77 [CI, 0.66 to 0.90]) but no significant risk reduction in terms of ICU admission (molnupiravir: HR, 1.02 [CI, 0.76 to 1.36]; nirmatrelvir-ritonavir: HR, 1.08 [CI, 0.58 to 2.02]) or the need for ventilatory support (molnupiravir: HR, 1.07 [CI, 0.89 to 1.30]; nirmatrelvir-ritonavir: HR, 1.03 [CI, 0.70 to 1.52]). There was no significant interaction between drug treatment and the number of COVID-19 vaccine doses received, thereby supporting the effectiveness of oral antivirals regardless of vaccination status. No significant interaction between nirmatrelvir-ritonavir treatment and age, sex, or Charlson Comorbidity Index was observed, whereas molnupiravir tended to be more effective in older people.

LIMITATION

The outcome of ICU admission or need for ventilatory support may not capture all severe COVID-19 cases; unmeasured confounders, such as obesity and health behaviors, may exist.

CONCLUSION

Molnupiravir and nirmatrelvir-ritonavir reduced all-cause mortality in both vaccinated and unvaccinated hospitalized patients. No significant reduction in ICU admission or the need for ventilatory support was observed.

PRIMARY FUNDING SOURCE

Health and Medical Research Fund Research on COVID-19, Government of the Hong Kong Special Administrative Region; Research Grants Council, Collaborative Research Fund; and Health Bureau, Government of the Hong Kong Special Administrative Region.

Efficacy of nirmatrelvir and ritonavir for post-acute COVID-19 sequelae beyond 3 months of SARS-CoV-2 infection

The effect of nirmatrelvir plus ritonavir (NMV-r) on post-acute COVID-19 sequelae beyond 3 months of SARS-CoV-2 infection remains unknown. This retrospective cohort study utilized data from the TriNetX Research Network. We identified nonhospitalized adult patients with COVID-19 receiving a diagnosis between January 1 and July 31, 2022. Propensity score matching (PSM) was used to create two matched cohorts: NMV-r and non-NMV-r groups, respectively. We measured the primary outcomes using a composite of all-cause emergency room (ER) visits or hospitalization and a composite of post-COVID-19 symptoms according to the WHO Delphi consensus, which also stated that post COVID-19 condition occurs usually 3 months from the onset of COVID-19, during the follow-up period between 90 days after the index diagnosis of COVID-19 and the end of follow-up (180 days). Initially, we identified 12 247 patients that received NMV-r within 5 days of diagnosis and 465 135 that did not. After PSM, 12 245 patients remained in each group. During the follow-up period, patients treated with NMV-r had a lower risk of all-cause hospitalization and ER visits compared with untreated patients (659 vs. 955; odds ratio [OR], 0.672; 95% confidence interval [CI], 0.607-0.745; p < 0.0001). However, the overall risk of post-acute COVID-19 symptoms did not significantly differ between the two groups (2265 vs. 2187; OR, 1.043; 95% CI, 0.978-1.114; p = 0.2021). The reduced risk of all-cause ER visits or hospitalization in the NMV-r group and the similarities in the risk of post-acute COVID-19 symptoms between the two groups were consistent in the subgroups stratified by sex, age, and vaccination status. Early NMV-r treatment of nonhospitalized patients with COVID-19 was associated with reduced risk of hospitalization and ER visits during the period of 90-180 days after diagnosis compared with no NMV-r treatment; however, post-acute COVID-19 symptoms and mortality risk did not differ significantly between the groups.

Nirmatrelvir-ritonavir compared with other antiviral drugs for the treatment of COVID-19 patients: A systematic review and meta-analysis

At present, there are some differences in the research results of nirmatrelvir-ritonavir compared with other antiviral drugs for the treatment of COVID-19 patients. We aimed to evaluate the efficacy and safety of nirmatrelvir-ritonavir compared with other antiviral drugs and the impact of different antiviral drugs on the short- and long-term effects of COVID-19. PubMed, Embase, CENTRAL (Cochrane Central Register of Controlled Trials), Web of Science, Google Scholar, and MedRxiv were searched to identify relevant studies from inception to March 30, 2023. We conducted a meta-analysis to estimate the effects of nirmatrelvir-ritonavir compared with other antiviral drugs for the treatment of COVID-19 patients and safety outcomes. The RoB1 and ROBINS-I were used to assess the bias risk of the included studies. Revman 5.4 software was used for meta-analysis (PROSPERO Code No: CRD42023397816). Twelve studies were included, including 30 588 COVID-19 patients, of whom 13 402 received nirmatrelvir-ritonavir. The meta-analysis results showed that the nirmatrelvir-ritonavir group had a lower proportion of patients than the control group in terms of long-term mortality (odds ratio [OR] = 0.29, 95% confidence interval [CI]: 0.13-0.66), hospitalization (OR = 0.44, 95% CI: 0.37-0.53, short term; OR = 0.52, 95% CI: 0.36-0.77, long term), and disease progression (OR = 0.56, 95% CI: 0.38-0.83, short term; OR = 0.60, 95% CI: 0.48-0.74, long term), and nirmatrelvir ritonavir showed little difference in safety compared to the control group. Nirmatrelvir-ritonavir can reduce the mortality and hospitalization of COVID-19 patients compared with other antiviral drugs. Further large-scale studies remain to validate these findings.

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.

The Impact of Nirmatrelvir-Ritonavir in Reducing Hospitalizations Among High-Risk Patients with SARS-Cov-2 During the Omicron Predominant Era

BACKGROUND

The coronavirus disease 2019 (COVID-19) pandemic has caused significant morbidity and mortality in high-risk populations. Several therapeutics have been developed to reduce the risk of COVID-19 related complications, hospitalizations, and death. In several studies, nirmatrelvir-ritonavir (NR) was reported to reduce the risk of hospitalizations and death. We aimed to evaluate the efficacy of NR in preventing hospitalizations and death during the Omicron predominant period.

METHODS

We retrospectively evaluated patients from June 1, 2022, through September 26, 2022. There was a total of 25,939 documented COVID-19 cases. Using propensity matching, we matched 5,754 NR treated patients with untreated patients.

RESULTS

Post-matching, the median age of the nirmatrelvir-ritonavir (NR) treated group was 58 years (interquartile range [IQR], 43-70 years) and 42% were vaccinated. Post-matching composite outcome of the 30-day hospitalization and mortality in the NR treated group were 0.9% (95%: CI 0.7% to 1.2%) vs. 2.1% (95% CI: 1.8% to 2.5%) in the matched control group, with a difference of -1.2 (-1.7, -0.8), P-value <0.01. The difference rates (NR vs. control) in 30-day all-cause hospitalizations and mortality were -1.2% (95% CI: -1.6% to -0.7%, p-value <0.01) and-0.1% (95% CI, -0.2% to 0.0%, P value= 0.29), respectively. We found similar finding across different age groups (≥65 vs. <65) and the vaccinated group.

CONCLUSION

We report a significant benefit with the use of NR in reducing hospitalizations among various high-risk COVID-19 groups during the Omicron BA.5 predominant period.