Real-world use of nirmatrelvir-ritonavir in outpatients with COVID-19 during the era of omicron variants including BA.4 and BA.5 in Colorado, USA: a retrospective cohort study

Associations of nirmatrelvir-ritonavir treatment with death and clinical improvement in hospitalized patients with COVID-19 during the Omicron wave in Beijing, China: a multicentre, retrospective cohort study

BACKGROUND

The effectiveness of nirmatrelvir-ritonavir has mainly been shown in non-hospitalized patients with mild-to-moderate coronavirus disease 2019 (COVID-19). The real-world effectiveness of nirmatrelvir-ritonavir urgently needs to be determined using representative in-hospital patients with COVID-19 during the Omicron wave of the pandemic.

METHODS

We performed a multicentre, retrospective study in five Chinese PLA General Hospital medical centers in Beijing, China. Patients hospitalized with COVID-19 from 10 December 2022 to 20 February 2023 were eligible for inclusion. A 1:1 propensity score matching was performed between the nirmatrelvir-ritonavir group and the control group.

RESULTS

1010 recipients of nirmatrelvir-ritonavir and 1010 matched controls were finally analyzed after matching. Compared with matched controls, the nirmatrelvir-ritonavir group had a lower incidence rate of all-cause death (4.6/1000 vs. 6.3/1000 person-days, p = 0.013) and a higher incidence rate of clinical improvement (47.6/1000 vs. 45.8/1000 person-days, p = 0.012). Nirmatrelvir-ritonavir was associated with a 22% lower all-cause mortality and a 14% higher incidence of clinical improvement. Initiation of nirmatrelvir-ritonavir within 5 days after symptom onset was associated with a 50% lower mortality and a 26% higher clinical improvement rate. By contrast, no significant associations were identified among patients receiving nirmatrelvir-ritonavir treatment more than 5 days after symptom onset. Nirmatrelvir-ritonavir was also associated with a 50% increase in survival days and a 12% decrease in days to clinical improvement.

CONCLUSION

Among hospitalized patients with COVID-19 during the Omicron wave in Beijing, China, the early initiation of nirmatrelvir-ritonavir was associated with clinical benefits of lowering mortality and improving clinical recovery.

Nirmatrelvir/ritonavir or Molnupiravir for treatment of non-hospitalized patients with COVID-19 at risk of disease progression

BACKGROUND

In randomized controlled trials, Nirmatrelvir/ritonavir (NMV/r) and Molnupiravir (MPV) reduced the risk of severe/fatal COVID-19 disease. Real-world data are limited, particularly studies directly comparing the two agents.

METHODS

Using the VA National COVID-19 database, we identified previously uninfected, non-hospitalized individuals with COVID-19 with ≥1 risk factor for disease progression who were prescribed either NMV/r or MPV within 3 days of a positive test. We used inverse probability of treatment weights (IPTW) to account for providers' preferences for a specific treatment. Absolute risk difference (ARD) with 95% confidence intervals were determined for those treated with NMV/r vs. MPV. The primary outcome was hospitalization or death within 30 days of treatment prescription using the IPTW approach. Analyses were repeated using propensity-score matched groups.

RESULTS

Between January 1 and November 30, 2022, 9,180 individuals were eligible for inclusion (6,592 prescribed NMV/r; 2,454 prescribed MPV). The ARD for hospitalization/death for NMV/r vs MPV was -0.25 (95% CI -0.79 to 0.28). There was no statistically significant difference in ARD among strata by age, race, comorbidities, or symptoms at baseline. Kaplan-Meier curves did not demonstrate a difference between the two groups (p-value = 0.6). Analysis of the propensity-score matched cohort yielded similar results (ARD for NMV/r vs. MPV -0.9, 95% CI -2.02 to 0.23). Additional analyses showed no difference for development of severe/critical/fatal disease by treatment group.

CONCLUSION

We found no significant difference in short term risk of hospitalization or death among at-risk individuals with COVID-19 treated with either NMV/r or MPV.

Clinical Outcome and 7-Day Virological Clearance in High-Risk Patients with Mild-Moderate COVID-19 Treated with Molnupiravir, Nirmatrelvir/Ritonavir, or Remdesivir

INTRODUCTION

We compared the effectiveness and virological clearance (VC) at day 7 (T7) post-treatment with molnupiravir, nirmatrelvir/ritonavir, and remdesivir in SARS-CoV-2-infected patients at high risk (HR) for clinical progression.

METHODS

We conducted a retrospective study enrolling HR patients with mild-to-moderate COVID-19 (Jan-Oct 2022) treated with nirmatrelvir/ritonavir or molnupiravir or 3 days of remdesivir. We investigated clinical recovery at T7 (resolution of symptoms for ≥ 72 h or all-cause death), VC at T7 (PCR/antigenic negative nasopharyngeal swab), and median time to VC (days from symptom onset to the first negative swab). Factors associated with VC were investigated by logistic regression.

RESULTS

In the study, 92/376 (43.8%) patients received molnupiravir, 150/376 (24.7%) nirmatrelvir/ritonavir, and 134/376 (31.5%) remdesivir. Forty-nine (13%) patients were unvaccinated or incompletely vaccinated. Patients treated with nirmatrelvir/ritonavir were younger and presented immunodeficiencies more frequently; remdesivir was used more commonly in patients hospitalized for other diseases. A high proportion of patients obtained clinical recovery without differences among the therapies (97.5% for molnupiravir, 98.3% for nirmatrelvir/ritonavir, and 93.6% for remdesivir); 12 (3.7%) patients died. Nirmatrelvir/ritonavir was associated with a higher proportion of T7 VC and a shorter time to VC compared to molnupiravir/remdesivir, also after adjustment for age and immunodeficiency (AOR 0.445 RDV vs. NMV-r, 95% CI 0.240-0.826, p = 0.010; AOR 0.222 MNP vs. NMV-r, 95% CI 0.105-0.472, p < 0.001).

CONCLUSIONS

SARS-COV-2 antiviral treatments are an excellent therapeutic strategy in HR patients. Nirmatrelvir/ritonavir showed a higher proportion of VC as early as 7 days after treatment, confirming its likely superiority in indirect comparisons.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Effectiveness of nirmatrelvir/ritonavir and molnupiravir in non-hospitalized adults with COVID-19: systematic review and meta-analysis of observational studies

OBJECTIVE

To determine the effectiveness of nirmatrelvir/ritonavir and molnupiravir among vaccinated and unvaccinated non-hospitalized adults with COVID-19.

METHODS

Observational studies of nirmatrelvir/ritonavir or molnupiravir compared to no antiviral drug treatment for COVID-19 in non-hospitalized adults with data on vaccination status were included. We searched MEDLINE, EMBASE, Scopus, Web of Science, WHO COVID-19 Research Database and medRxiv for reports published between 1 January 2022 and 8 November 2023. The primary outcome was a composite of hospitalization or mortality up to 35 days after COVID-19 diagnosis. Risk of bias was assessed with ROBINS-I. Risk ratios (RR), hazard ratios (HR) and risk differences (RD) were separately estimated using random-effects models.

RESULTS

We included 30 cohort studies on adults treated with nirmatrelvir/ritonavir (n = 462 279) and molnupiravir (n = 48 008). Nirmatrelvir/ritonavir probably reduced the composite outcome (RR 0.62, 95%CI 0.55-0.70; I2 = 0%; moderate certainty) with no evidence of effect modification by vaccination status (RR Psubgroup = 0.47). In five studies, RD estimates against the composite outcome for nirmatrelvir/ritonavir were 1.21% (95%CI 0.57% to 1.84%) in vaccinated and 1.72% (95%CI 0.59% to 2.85%) in unvaccinated subgroups.Molnupiravir may slightly reduce the composite outcome (RR 0.75, 95%CI 0.67-0.85; I2 = 32%; low certainty). Evidence of effect modification by vaccination status was inconsistent among studies reporting different effect measures (RR Psubgroup = 0.78; HR Psubgroup = 0.08). In two studies, RD against the composite outcome for molnupiravir were -0.01% (95%CI -1.13% to 1.10%) in vaccinated and 1.73% (95%CI -2.08% to 5.53%) in unvaccinated subgroups.

CONCLUSIONS

Among cohort studies of non-hospitalized adults with COVID-19, nirmatrelvir/ritonavir is effective against the composite outcome of severe COVID-19 independent of vaccination status. Further research and a reassessment of molnupiravir use among vaccinated adults are warranted.

REGISTRATION

PROSPERO CRD42023429232.

Symptoms, Viral Loads, and Rebound Among COVID-19 Outpatients Treated With Nirmatrelvir/Ritonavir Compared With Propensity Score-Matched Untreated Individuals

BACKGROUND

Nirmatrelvir/ritonavir (N/R) reduces severe outcomes from coronavirus disease 2019 (COVID-19); however, rebound after treatment has been reported. We compared symptom and viral dynamics in individuals with COVID-19 who completed N/R treatment and similar untreated individuals.

METHODS

We identified symptomatic participants who tested severe acute respiratory syndrome coronavirus 2-positive and were N/R eligible from a COVID-19 household transmission study. Index cases from ambulatory settings and their households contacts were enrolled. We collected daily symptoms, medication use, and respiratory specimens for quantitative polymerase chain reaction for 10 days during March 2022-May 2023. Participants who completed N/R treatment (treated) were propensity score matched to untreated participants. We compared symptom rebound, viral load (VL) rebound, average daily symptoms, and average daily VL by treatment status measured after N/R treatment completion or 7 days after symptom onset if untreated.

RESULTS

Treated (n = 130) and untreated participants (n = 241) had similar baseline characteristics. After treatment completion, treated participants had greater occurrence of symptom rebound (32% vs 20%; P = .009) and VL rebound (27% vs 7%; P < .001). Average daily symptoms were lower among treated participants without symptom rebound (1.0 vs 1.6; P < .01) but not statistically lower with symptom rebound (3.0 vs 3.4; P = .5). Treated participants had lower average daily VLs without VL rebound (0.9 vs 2.6; P < .01) but not statistically lower with VL rebound (4.8 vs 5.1; P = .7).

CONCLUSIONS

Individuals who completed N/R treatment experienced fewer symptoms and lower VL but rebound occured more often compared with untreated individuals. Providers should prescribe N/R, when indicated, and communicate rebound risk to patients.

Paxlovid™ reduces the incidence of pneumonia, hospitalization, and death in a cohort of COVID-19 patients from northeast Mexico

BACKGROUND

Information on Paxlovid™ effectiveness must be monitored and updated in real world scenarios. Our research question was what is the effectiveness of Paxlovid™ in adult patients with COVID-19? Therefore, we investigated the effectiveness of Paxlovid™ on reducing the incidence of pneumonia, hospitalization, and mortality in a cohort of COVID-19 positive adult patients from northeast Mexico.

METHODS

A retrospective cohort study of COVID-19 positive adult patients from Nuevo Leon, Mexico from December 2020 to May 2023 (after Omicron BA-5 circulation) was performed. Paxlovid™ use was authorized in September 2022. Therefore, we analyzed effectiveness in patients with confirmed diagnosis who met selection criteria between September 2022 and May 2023 (n = 20,799; 5,673 with and 15,126 without Paxlovid™).

RESULTS

The pneumonia (0.1% vs. 0.4%, p < 0.0001), hospitalization (0.1% vs. 1.2%, p < 0.0001), and death rates (0.04% vs. 0.2%, p < 0.0001) were lower in patients with Paxlovid™ treatment independently of age, sex, comorbidity, and COVID-19 and pneumococcal vaccination history. Effectiveness was 88.2%, 95.9% y 91.9% for pneumonia, hospitalization, and death, respectively.

CONCLUSIONS

Paxlovid™ reduces the presentation of pneumonia, hospitalization, and death secondary to COVID-19. It is recommended to continue monitoring Paxlovid™ effectiveness, as other SARS-CoV-2 variants continue to emerge.

Viral clearance as a surrogate of clinical efficacy for COVID-19 therapies in outpatients: a systematic review and meta-analysis

BACKGROUND

Surrogates of antiviral efficacy are needed for COVID-19. We aimed to investigate the relationship between the virological effect of treatment and clinical efficacy as measured by progression to severe disease in outpatients treated for mild-to-moderate COVID-19.

METHODS

In this systematic review and meta-analysis, we searched PubMed, Scopus, and medRxiv from database inception to Aug 16, 2023, for randomised placebo-controlled trials that tested virus-directed treatments (ie, any monoclonal antibodies, convalescent plasma, or antivirals) in non-hospitalised individuals with COVID-19. We only included studies that reported both clinical outcomes (ie, rate of disease progression to hospitalisation or death) and virological outcomes (ie, viral load within the first 7 days of treatment). We extracted summary data from eligible reports, with discrepancies resolved through discussion. We used an established meta-regression model with random effects to assess the association between clinical efficacy and virological treatment effect, and calculated I2 to quantify residual study heterogeneity.

FINDINGS

We identified 1718 unique studies, of which 22 (with a total of 16 684 participants) met the inclusion criteria, and were in primarily unvaccinated individuals. Risk of bias was assessed as low in 19 of 22 studies for clinical outcomes, whereas for virological outcomes, a high risk of bias was assessed in 11 studies, some risk in ten studies, and a low risk in one study. The unadjusted relative risk of disease progression for each extra log10 copies per mL reduction in viral load in treated compared with placebo groups was 0·12 (95% CI 0·04-0·34; p<0·0001) on day 3, 0·20 (0·08-0·50; p=0·0006) on day 5, and 0·53 (0·30-0·94; p=0·030) on day 7. The residual heterogeneity in our meta-regression was estimated as low (I2=0% [0-53] on day 3, 0% [0-71] on day 5, and 0% [0-43] on day 7).

INTERPRETATION

Despite the aggregation of studies with differing designs, and evidence of risk of bias in some virological outcomes, this review provides evidence that treatment-induced acceleration of viral clearance within the first 5 days after treatment is a potential surrogate of clinical efficacy to prevent hospitalisation with COVID-19. This work supports the use of viral clearance as an early phase clinical trial endpoint of therapeutic efficacy.

FUNDING

Australian Government Department of Health, Medical Research Future Fund, and Australian National Health and Medical Research Council.

The Management of Patients at High Risk of Serious COVID-19 Disease: Optimising the Patient Pathway in the Middle East, Africa, and Eastern Europe

Introduction For patients at high risk of severe COVID-19 disease, antiviral therapeutic options are available to reduce the risk of hospitalization or death. Although many countries have developed national guidelines for COVID-19 management that include use of antiviral agents, it is unclear how these guidelines are used in daily clinical practice. This study aims to assess the management of high-risk COVID-19 patients in the Middle East, Africa, and Eastern Europe, with a focus on understanding current practices, challenges, and potential strategies for improvement. Methods Healthcare professionals (HCPs) from the Middle East, Africa, and Eastern Europe came together at a regional summit in February 2023 to share perspectives on the therapeutic management of patients at high risk of serious COVID-19 disease in the community. Summit participants represented diverse medical specialties, geographical regions, and healthcare settings. Key insights gathered during the summit were supplemented with evidence from the published literature via a non-systematic literature search of MEDLINE and online sources such as government reports since the start of 2020 to identify articles on disease burden, unmet needs, treatment access, antiviral therapy, guidelines related to individuals with COVID-19 at high-risk for poor outcomes in low- and middle-income countries (LMICs). Together, these sources were used by the authors to generate their recommendations for future priorities and optimal care pathways globally. Results Specific insights gathered from the summit were that participants reported that primary care is the first point of contact for high-risk patients, but the role of primary care physicians (PCPs) in treatment is uncertain. Additionally, participants highlighted that between-country differences in the care pathway for high-risk patients are due to variations in local treatment practices, healthcare system structures, and resourcing. In line with the published literature, participants agreed that HCP education is needed to support the identification, counseling, and appropriate management of high-risk patients and that pharmacists have a critical role to play in identifying clinically important potential interactions with antiviral treatment and recommending appropriate adjustments. Furthermore, patient hesitancy can result in late presentation, delayed treatment, and potential progression of symptoms. HCPs should proactively counsel high-risk patients, so they are aware of their risk and its implications and understand what to do if they experience symptoms of COVID-19. Targeted educational initiatives for patients are needed to mitigate reluctance to undergo COVID-19 testing and counter COVID-19 misinformation. Conclusion Collaboration among stakeholders is essential to optimize COVID-19 management for high-risk patients globally, ensuring effective implementation of guidelines and improving outcomes.

Effectiveness of Nirmatrelvir-Ritonavir for the Prevention of COVID-19-Related Hospitalization and Mortality: A Systematic Literature Review

BACKGROUND

Nirmatrelvir/ritonavir (NMV/r) is an oral antiviral drug used to treat mild-to-moderate coronavirus disease 2019 (COVID-19) in patients aged 12 years or older at high risk of progression to severe disease (eg, hospitalization and death). Despite being the preferred option for outpatient treatment in the majority of countries worldwide, NMV/r is currently underutilized in real-world clinical practice.

AREAS OF UNCERTAINTY

As numerous real-world studies have described patient outcomes following treatment with NMV/r, this systematic literature review provides a comprehensive summary of evidence on NMV/r effectiveness against hospitalization and mortality further organized by clinically meaningful categories, such as acute versus longer-term follow-up, age, underlying health conditions, and vaccination status, to help inform health care decision making.

DATA SOURCES

We searched Embase and PubMed (December 22, 2021-March 31, 2023) and congress abstracts (December 1, 2021-December 31, 2022) for reports describing NMV/r effectiveness.

THERAPEUTIC ADVANCES

In total, 18 real-world studies met final selection criteria. The evidence showed that NMV/r significantly reduced postinfection risk of all-cause and COVID-19-related hospitalization and mortality in both acute (≤30 days) (21%-92%) and longer-term (>30 days) (1%-61%) follow-up. The reduction in postinfection risk was higher when treatment was received within 5 days of symptom onset. Real-world effectiveness of NMV/r treatment was observed regardless of age, underlying high-risk conditions, and vaccination status.

CONCLUSION

The systematic literature review findings demonstrated the effectiveness of NMV/r against hospitalization and mortality during the Omicron period among individuals at high risk of progression to severe COVID-19 disease.

Real-world application of nirmatrelvir/ritonavir in hospitalized COVID-19 patients with onset of symptoms beyond 5 days: a comparative study

PURPOSE

Physicians may administer Nirmatrelvir-ritonavir to patients who have been symptomatic for more than 5 days. There is currently no clear evidence to support this approach.

METHODS

A real-world study was conducted to investigate the potential relationship between the administration of Nirmatrelvir-ritonavir and the rates of intubation or in-hospital mortality among COVID-19 patients who experienced symptoms for more than 5 days. The end point was a composite event of intubation or in-hospital mortality. The outcomes between those patients who received Nirmatrelvir-ritonavir and those who did not were compared.

RESULTS

A total of 847 patients were included in the analysis. Among them, 312 patients (36.84%) received Nirmatrelvir-ritonavir. Within the entire population, 86 patients (10.15%) experienced intubation or in-hospital mortality. The main analysis indicated that there was a significant association between the application of Nirmatrelvir-ritonavir and intubation or in-hospital mortality, with an odds ratio of 0.50 (95% confidence interval, 0.28 to 0.87; P = 0.0153) using inverse probability of treatment weighting. The finding was consistent with multiple sensitivity analyses.

CONCLUSIONS

The application of Nirmatrelvir-ritonavir was associated with a significantly reduced risk of intubation or death in hospitalized COVID-19 patients who experienced symptoms for more than 5 days as compared to those who did not receive the treatment.

COVID-19 hospitalization risk after outpatient nirmatrelvir/ritonavir use, January to August 2022, North Carolina

BACKGROUND

In the USA, nirmatrelvir/ritonavir is authorized for the treatment of mild-to-moderate COVID-19 in patients at least 12 years of age, at high risk for progression to severe COVID-19.

OBJECTIVES

To estimate the impact of outpatient nirmatrelvir/ritonavir on COVID-19 hospitalization risk in a US healthcare system.

METHODS

We conducted a cohort study using electronic health records among outpatients with a positive SARS-CoV-2 PCR test between January and August 2022. We evaluated the association of nirmatrelvir/ritonavir therapy with time to hospitalization by estimating adjusted HRs and assessed the impact of nirmatrelvir/ritonavir on predicted COVID-19 hospitalizations using machine-learning methods.

RESULTS

Among 44 671 patients, 4948 (11%) received nirmatrelvir/ritonavir, and 201 (0.4%) were hospitalized within 28 days of COVID-19 diagnosis. Nirmatrelvir/ritonavir recipients were more likely to be older, white, vaccinated, have comorbidities and reside in areas with higher average socioeconomic status. The 28 day cumulative incidence of hospitalization was 0.06% (95% CI: 0.02%-0.17%) among nirmatrelvir/ritonavir recipients and 0.52% (95% CI: 0.46%-0.60%) among non-recipients. For nirmatrelvir/ritonavir versus no therapy, the age-adjusted HR was 0.08 (95% CI: 0.03-0.26); the fully adjusted HR was 0.16 (95% CI: 0.05-0.50). In the machine-learning model, the primary features reducing predicted hospitalization risk were nirmatrelvir/ritonavir, younger age, vaccination, female gender and residence in a higher socioeconomic status area.

CONCLUSIONS

COVID-19 hospitalization risk was reduced by 84% among nirmatrelvir/ritonavir recipients in a large, diverse healthcare system during the Omicron wave. These results suggest that nirmatrelvir/ritonavir remained highly effective in a setting substantially different than the original clinical trials.

Managing acute COVID-19 in immunocompromised pediatric patients

INTRODUCTION

SARS-CoV-2 infection is a potentially life-threatening infection in immunocompromised pediatric patients, and its management has rapidly evolved during the pandemic. To control SARS-CoV-2 infection over time, the scenario changed for the better with the introduction of specific treatments such as antiviral drugs, vaccines, and monoclonal antibodies, together with drugs blocking the inflammatory cytokine cascade and improvements in supportive care.

AREAS COVERED

This paper discusses the therapeutic strategies to apply for patients affected by COVID-19 in the pediatric population, with a focus on the immunocompromised patients.

EXPERT OPINION

Treatment in pediatric patients retraces the therapies investigated and approved in adults and must be calibrated on the basis of the severity of the infection (anti-spike monoclonal antibody, antivirals, anti-inflammatory drugs, and immunomodulators). Transmission prevention policies and vaccination reduce the risk of infection, while early intervention in the immunocompromised patients at high-risk of progression to severe-critical COVID-19 may reduce the period of viral shedding and the need for hospitalization, intensive care admission, and death. In hemato-oncological patients, the delayed treatment of SARS-CoV-2 infection or COVID-19 disease represents a frequent complication and its impact on the patient outcome remains a matter of research for the next few years.

Predictors of nirmatrelvir-ritonavir receipt among COVID-19 patients in a large US health system

A clear understanding of real-world uptake of nirmatrelvir-ritonavir for treatment of SARS-CoV-2 can inform treatment allocation strategies and improve interpretation of effectiveness studies. We used data from a large US healthcare system to describe nirmatrelvir-ritonavir dispenses among all SARS-CoV-2 positive patients aged ≥ 12 years meeting recommended National Institutes of Health treatment eligibility criteria for the study period between 1 January and 31 December, 2022. Overall, 10.9% (N = 34,791/319,900) of treatment eligible patients with SARS-CoV-2 infections received nirmatrelvir-ritonavir over the study period. Although uptake of nirmatrelvir-ritonavir increased over time, by the end of 2022, less than a quarter of treatment eligible patients with SARS-CoV-2 infections had received nirmatrelvir-ritonavir. Across patient demographics, treatment was generally consistent with tiered treatment guidelines, with dispenses concentrated among patients aged ≥ 65 years (14,706/63,921; 23.0%), and with multiple comorbidities (10,989/54,431; 20.1%). However, neighborhoods of lower socioeconomic status (upper third of neighborhood deprivation index [NDI]) had between 12% (95% CI: 7-18%) and 28% (25-32%) lower odds of treatment dispense over the time periods studied compared to the lower third of NDI distribution, even after accounting for demographic and clinical characteristics. A limited chart review (N = 40) confirmed that in some cases a decision not to treat was appropriate and aligned with national guidelines to use clinical judgement on a case-by-case basis. There is a need to enhance patient and provider awareness on the availability and benefits of nirmatrelvir-ritonavir for the treatment of COVID-19 illness.

Intensive Care Unit Mortality Trends during the First Two Years of the COVID-19 Pandemic in Greece: A Multi-Center Retrospective Study

Data on COVID-19 mortality among patients in intensive care units (ICUs) from Eastern and/or Southern European countries, including Greece, are limited. The purpose of this study was to evaluate the ICU mortality trends among critically ill COVID-19 patients during the first two years of the pandemic in Greece and to further investigate if certain patients' clinical characteristics contributed to this outcome. We conducted a multi-center retrospective observational study among five large university hospitals in Greece, between February 2020 and January 2022. All adult critically ill patients with confirmed COVID-19 disease who required ICU admission for at least 24 h were eligible. In total, 1462 patients (66.35% males) were included in this study. The mean age of this cohort was 64.9 (±13.27) years old. The 28-day mortality rate was 35.99% (n = 528), while the overall in-hospital mortality was 50.96% (n = 745). Cox regression analysis demonstrated that older age (≥65 years old), a body mass index within the normal range, and a delay in ICU admission from symptom onset, as well as worse baseline clinical severity scores upon ICU admission, were associated with a greater risk of death. Mortality of critically ill COVID-19 patients was high during the first two years of the pandemic in Greece but comparable to other countries. Risk factors for death presented in this study are not different from those that have already been described for COVID-19 in other studies.

Guidance for prevention and management of COVID-19 in children and adolescents: A consensus statement from the Pediatric Infectious Diseases Society Pediatric COVID-19 Therapies Taskforce

BACKGROUND

Since November 2019, the SARS-CoV-2 pandemic has created challenges for preventing and managing COVID-19 in children and adolescents. Most research to develop new therapeutic interventions or to repurpose existing ones has been undertaken in adults, and although most cases of infection in pediatric populations are mild, there have been many cases of critical and fatal infection. Understanding the risk factors for severe illness and the evidence for safety, efficacy, and effectiveness of therapies for COVID-19 in children is necessary to optimize therapy.

METHODS

A panel of experts in pediatric infectious diseases, pediatric infectious diseases pharmacology, and pediatric intensive care medicine from 21 geographically diverse North American institutions was re-convened. Through a series of teleconferences and web-based surveys and a systematic review with meta-analysis of data for risk factors, a guidance statement comprising a series of recommendations for risk stratification, treatment, and prevention of COVID-19 was developed and refined based on expert consensus.

RESULTS

There are identifiable clinical characteristics that enable risk stratification for patients at risk for severe COVID-19. These risk factors can be used to guide the treatment of hospitalized and non-hospitalized children and adolescents with COVID-19 and to guide preventative therapy where options remain available.

COVID-19 prophylaxis, diagnostics, and treatment in patients with rheumatic diseases. The Polish experts panel opinion

As severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) evolves, infection management in vulnerable populations requires formalized guidance. Although low-virulence variants of SARS-CoV-2 remain predominant, they pose an increased risk of severe illness in adults with rheumatic and musculoskeletal diseases (RMDs). Several disease-specific (chronic long-grade inflammation, concomitant immunosuppression) and individual (advanced age, multimorbidity, pregnancy, vaccination status) factors contribute to excess risk in RMD populations. Various post-COVID-19 manifestations are also increasingly reported and appear more commonly than in the general population. At a pathogenetic level, complex interplay involving innate and acquired immune dysregulation, viral persistence, and genetic predisposition shapes a unique susceptibility profile. Moreover, incident cases of SARS-CoV-2 infection as a trigger factor for the development of autoimmune conditions have been reported. Vaccination remains a key preventive strategy, and encouraging active education and awareness will be crucial for rheumatologists in the upcoming years. In patients with RMDs, COVID-19 vaccines' benefits outweigh the risks. Derivation of specialized diagnostic and therapeutic protocols within a comprehensive COVID-19 care plan represents an ideal scenario for healthcare system organization. Vigilance for symptoms of infection and rapid diagnosis are key for introducing antiviral treatment in patients with RMDs in a timely manner. This review provides updated guidance on optimal immunization, diagnosis, and antiviral treatment strategies.

Resilience to emerging infectious diseases and the importance of scientific innovation

This opinion piece emphasies the critical role of translational research in enhancing the UK's resilience against future pandemics. The COVID-19 pandemic demonstrated the lifesaving potential of scientific innovation, including genomic tracking of SARS-CoV-2, vaccine development, data linkage, modelling, and new treatments. These advances, achieved through collaborations between academic institutions, industry, government, public health bodies, and the NHS, occurred at an unprecedented pace. However, the UK's pandemic preparedness planning, as reflected in the 2016 Exercise Cygnus report, notably lacked provision for scientific innovation. This oversight highlights the necessity of integrating innovation and research into future preparedness strategies, not as a luxury but as a vital component of the healthcare infrastructure. The COVID-19 pandemic has underlined the importance of surge capacity for diagnostic labs, vaccine development and deployment strategies, real-time research embedded within the NHS, efficient data sharing, clear public communication, and the use of genomic tools for outbreak surveillance and monitoring pathogen response. Despite world-leading aspects of some of the UK's research response, the need to build much of the infrastructure in real-time led to avoidable delays. A proactive approach in incorporating research and innovation into the NHS's operational framework will be needed to ensure swift, evidence-based responses to future pandemics.

Real-world use of nirmatrelvir-ritonavir in COVID-19 outpatients during BQ.1, BQ.1.1., and XBB.1.5 predominant omicron variants in three U.S. health systems: a retrospective cohort study

Background

Ritonavir-boosted Nirmatrelvir (NMV-r), a protease inhibitor with in vitro activity against SARS-CoV-2, can reduce risk of progression to severe COVID-19 among high-risk individuals infected with earlier variants, but less is known about its effectiveness against omicron variants BQ.1/BQ.1.1/XBB.1.5. We sought to evaluate effectiveness of NMV-r in BQ.1/BQ.1.1/XBB.1.5 omicron variants by comparing hospitalisation rates to NMV-r treated patients during a previous omicron phase and to contemporaneous untreated patients.

Methods

We conducted a retrospective observational cohort study of non-hospitalised adult patients with SARS-CoV-2 infection using real-world data from three health systems in Colorado and Utah, and compared hospitalisation rates in NMV-r-treated patients in a BA.2/BA.2.12.1/BA.4/BA.5 variant-predominant (first) phase (April 3, 2022-November 12, 2022), with a BQ.1/BQ.1.1/XBB.1.5 variant-predominant (second) phase (November 13, 2022-March 7, 2023). In the primary analysis, we used Firth logistic regression with a two-segment (phase) linear time model, and pre-specified non-inferiority bounds for the mean change between segments. In a pre-specified secondary analysis, we inferred NMV-r effectiveness in a cohort of treated and untreated patients infected during the second phase. For both analyses, the primary outcome was 28-day all-cause hospitalisation. Subgroup analyses assessed treatment effect heterogeneity.

Findings

In the primary analysis, 28-day all-cause hospitalisation rates in NMV-r treated patients in the second phase (n = 12,061) were non-inferior compared to the first phase (n = 25,075) (198 [1.6%] vs. 345 [1.4%], adjusted odds ratio (aOR): 0.76 [95% CI 0.54-1.06]), with consistent results among secondary endpoints and key subgroups. Secondary cohort analyses revealed additional evidence for NMV-r effectiveness, with reduced 28-day hospitalisation rates among treated patients compared to untreated patients during a BQ.1/BQ.1.1/XBB.1.5 predominant phase (198/12,061 [1.6%] vs. 376/10,031 [3.7%], aOR 0.34 [95% CI 0.30-0.38), findings robust to additional sensitivity analyses.

Interpretation

Real-world evidence from major US healthcare systems suggests ongoing NMV-r effectiveness in preventing hospitalisation during a BQ.1/BQ.1.1/XBB.1.5-predominant phase in the U.S, supporting its continued use in similar patient populations.

Funding

U.S. National Institutes of Health.

Cost-effectiveness of nirmatrelvir/ritonavir for high-risk adult outpatients with COVID-19 in Japan

INTRODUCTION

This study aimed to evaluate the cost-effectiveness of nirmatrelvir/ritonavir (Nir/Rit) for adult outpatients with COVID-19 from the perspective of a Japanese public healthcare payer.

METHODS

A cost-effectiveness simulation was conducted comparing Nir/Rit for the outpatient treatment of high-risk COVID-19 patients to best supportive care (BSC) without antiviral or antibody drugs. The analytical model was divided into two phases: the treatment phase, lasting 35 days from the start of COVID-19 treatment, and the post-treatment phase. Patients who survived the treatment phase were assumed to follow a general population survival curve. Expected costs and expected quality-adjusted life years (QALYs) for both BSC and Nir/Rit were calculated for ages 40 to 80 to obtain the incremental cost-effectiveness ratio (ICER). The robustness of the results was evaluated through deterministic and probabilistic sensitivity analysis (PSA).

RESULTS

The ICERs for patients aged 40, 50, 60, 70, and 80 were 18,854,276 Japanese Yen (JPY)/QALY, 8,482,034 JPY/QALY, 4,976,612 JPY/QALY, 2,636,096 JPY/QALY, and 1,597,783 JPY/QALY, respectively. In the deterministic sensitivity analysis, both the mortality risk during the treatment phase and the relative mortality risk with Nir/Rit had a high impact on ICER across all ages. In the PSA, when the willingness-to-pay (WTP) threshold was set at 5 million JPY/QALY, the probability of the ICER being below the WTP threshold was 0%, 0.2%, 45.4%, 99.9%, and 100% at ages 40, 50, 60, 70, and 80, respectively.

CONCLUSION

Nir/Rit is cost-effective for older individuals aged 60 and over but not for younger age groups.

Oral COVID-19 Antiviral Uptake Among a Highly Vaccinated US Cohort of Adults With SARS-CoV-2 Infection Between December 2021 and October 2022

Background

We described the oral nirmatrelvir/ritonavir (NMV/r) and molnupiravir (MOV) uptake among a subgroup of highly vaccinated adults in a US national prospective cohort who were infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) between 12/2021 and 10/2022.

Methods

We estimate antiviral uptake within 5 days of SARS-CoV-2 infection, as well as age- and gender-adjusted antiviral uptake prevalence ratios by antiviral eligibility (based on age and comorbidities), sociodemographic characteristics, and clinical characteristics including vaccination status and history of long coronavirus disease 2019 (COVID).

Results

NMV/r uptake was 13.6% (95% CI, 11.9%-15.2%) among 1594 participants, and MOV uptake was 1.4% (95% CI, 0.8%-2.1%) among 1398 participants. NMV/r uptake increased over time (1.9%; 95% CI, 1.0%-2.9%; between 12/2021 and 3/2022; 16.5%; 95% CI, 13.0%-20.0%; between 4/2022 and 7/2022; and 25.3%; 95% CI, 21.6%-29.0%; between 8/2022 and 10/2022). Participants age ≥65 and those who had comorbidities for severe COVID-19 had higher NMV/r uptake. There was lower NMV/r uptake among non-Hispanic Black participants (7.2%; 95% CI, 2.4%-12.0%; relative to other racial/ethnic groups) and among individuals in the lowest income groups (10.6%; 95% CI, 7.3%-13.8%; relative to higher income groups). Among a subset of 278 participants with SARS-CoV-2 infection after 12/2021 who also had a history of prior SARS-CoV-2 infection, those with (vs without) a history of long COVID reported greater NMV/r uptake (22.0% vs 7.9%; P = .001). Among those prescribed NMV/r (n = 216), 137 (63%; 95% CI, 57%-70%) reported that NMV/r was helpful for reducing COVID-19 symptoms.

Conclusions

Despite proven effectiveness against severe outcomes, COVID-19 antiviral uptake remains low among those with SARS-CoV-2 infection in the United States. Further outreach to providers and patients to improve awareness of COVID-19 oral antivirals and indications is needed.

Effectiveness of subcutaneous monoclonal antibody treatment in emergency department outpatients with COVID-19

Objectives

To evaluate whether subcutaneous neutralizing monoclonal antibody (mAb) treatment given in the emergency department (ED) setting was associated with reduced hospitalizations, mortality, and severity of disease when compared to nontreatment among mAb-eligible patients with coronavirus disease 2019 (COVID-19).

Methods

This retrospective observational cohort study of ED patients utilized a propensity score-matched analysis to compare patients who received subcutaneous casirivimab and imdevimab mAb to nontreated COVID-19 control patients in November-December 2021. The primary outcome was all-cause hospitalization within 28 days, and secondary outcomes were 90-day hospitalization, 28- and 90-day mortality, and ED length of stay (LOS).

Results

Of 1340 patients included in the analysis, 490 received subcutaneous casirivimab and imdevimab, and 850 did not received them. There was no difference observed for 28-day hospitalization (8.4% vs. 10.6%; adjusted odds ratio [aOR] 0.79, 95% confidence intervals [CI] 0.53-1.17) or 90-day hospitalization (11.6% vs. 12.5%; aOR 0.93, 95% CI 0.65-1.31). However, mortality at both the 28-day and 90-day timepoints was substantially lower in the treated group (28-day 0.6% vs. 3.1%; aOR 0.18, 95% CI 0.08-0.41; 90-day 0.6% vs. 3.9%; aOR 0.14, 95% CI 0.06-0.36). Among hospitalized patients, treated patients had shorter hospital LOS (5.7 vs. 11.4 days; adjusted rate ratio [aRR] 0.47, 95% CI 0.33-0.69), shorter intensive care unit LOS (3.8 vs. 10.2 days; aRR 0.22, 95% CI 0.14-0.35), and the severity of hospitalization was lower (aOR 0.45, 95% CI 0.21-0.97) compared to untreated.

Conclusions

Among ED patients who presented for symptomatic COVID-19 during the Delta variant phase, ED subcutaneous casirivimab/imdevimab treatment was not associated with a decrease in hospitalizations. However, treatment was associated with lower mortality at 28 and 90 days, hospital LOS, and overall severity of illness.

Effectiveness of nirmatrelvir-ritonavir on severe outcomes of COVID-19 in the era of vaccination and Omicron: An updated meta-analysis

Nirmatrelvir-ritonavir (NR) was approved to treat SARS-CoV-2 positive outpatients at high risk of progression to severe disease, based on a randomized trial in unvaccinated patients. Effectiveness in vaccinated patients and against Omicron has not yet been confirmed by clinical trial data, but a recent meta-analysis suggested good real-world effectiveness based on 12 studies. We updated this meta-analysis by searching Medline and Embase databases for studies assessing effectiveness of NR on mortality, hospitalization, composite outcome of hospitalization and/or death, and progression to severe disease, published between October 1, 2022 and May 22, 2023. Random effects meta-analysis and subgroup analysis for vaccinated patients was performed. A total of 32 studies were included in the meta-analysis. Pooled RR for the effect of NR on mortality, hospitalization, hospitalization and/or mortality, and progression to severe disease were 0.36 (95% confidence interval [CI]: 0.25-0.52), 0.43 (CI: 0.37-0.51), 0.52 (CI: 0.45-0.61) and 0.54 (CI: 0.41-0.73), respectively. A subgroup analysis on vaccinated patients indicated lower effectiveness of NR on mortality (RR: 0.55, CI: 0.45-0.68), but similar effectiveness for hospitalization, hospitalization and/or mortality, or progression to severe disease (RR: 0.52, 0.58, and 0.66, respectively). This updated meta-analysis robustly confirms the protective effects of NR on severe COVID-19 outcomes.

Cost-Effectiveness of Oral Nirmatrelvir/Ritonavir in Patients at High Risk for Progression to Severe COVID-19 in the United States

OBJECTIVES

Nirmatrelvir/ritonavir (NMV/r) is an orally administered antiviral indicated for the outpatient treatment of patients with mild-to-moderate COVID-19 at high risk for disease progression to severe illness. We estimated the cost-effectiveness of NMV/r versus best supportive care for patients with mild-to-moderate COVID-19 at high risk for progression to severe illness from a US health sector perspective.

METHODS

A cost-effectiveness model was developed using a short-term decision-tree (1 year) followed by a lifetime 2-state Markov model (alive and dead). The short-term decision-tree captured costs and outcomes associated with the primary infection and healthcare utilization; survivors of the short-term decision-tree were followed until death assuming US quality-adjusted life years (QALYs), adjusted in the short-term for survivors of mechanical ventilation. Baseline rate of hospitalization and NMV/r effectiveness were taken from an Omicron-era US real-world study. Remaining inputs were informed by previous COVID-19 studies and publicly available US sources. Sensitivity analyses were conducted for all model inputs to test the robustness of model results.

RESULTS

NMV/r was found to decrease COVID-19 related hospitalizations (-0.027 per infected case) increase QALYs (+0.030), decrease hospitalization costs (-$1110), and increase total treatment cost (+$271), resulting in an incremental cost-effectiveness ratio of $8931/QALY. Results were most sensitive to baseline risk of hospitalization and NMV/r treatment effectiveness parameters. The probabilistic analysis indicated that NMV/r has a >99% probability of being cost-effective at a $100 000 willingness-to-pay threshold.

CONCLUSIONS

NMV/r is cost-effective vs best supportive care for patients at high risk for severe COVID-19 from a US health sector perspective.

Exploring Paxlovid Efficacy in COVID-19 Patients with MAFLD: Insights from a Single-Center Prospective Cohort Study

This study investigates the intricate interplay between Metabolic-associated Fatty Liver Disease (MAFLD) and COVID-19, exploring the impact of MAFLD on disease severity, outcomes, and the efficacy of the antiviral agent Paxlovid (nirmatrelvir/ritonavir). MAFLD, affecting a quarter of the global population, emerges as a potential risk factor for severe COVID-19, yet the underlying pathophysiological mechanisms remain elusive. This study focuses on the clinical significance of Paxlovid, the first orally bioavailable antiviral agent granted Emergency Use Authorization in the United States. Notably, outcomes from phase II/III trials exhibit an 88% relative risk reduction in COVID-19-associated hospitalization or mortality among high-risk patients. Despite conflicting data on the association between MAFLD and COVID-19 severity, this research strives to bridge the gap by evaluating the effectiveness of Paxlovid in MAFLD patients with COVID-19, addressing the scarcity of relevant studies.

Real-world effectiveness of nirmatrelvir-ritonavir versus azvudine in hospitalized patients with COVID-19 during the omicron wave in Beijing: a multicenter retrospective cohort study

BACKGROUND AND AIM

Two oral antivirals (Nirmatrelvir- ritonavir and Azvudine) are widely used in China practice during the Omicron wave of the pandemic. However, little evidence regarding the real-world effectiveness of these two oral antivirals in in-hospital patients. We aimed to evaluate the clinical effectiveness of nirmatrelvir-ritonavir versus azvudine among adult hospitalized patients with COVID-19.

METHODS

This retrospective cohort study used data from three Chinese PLA General Hospital medical centres. Hospitalized patients with COVID-19 treated with azvudine or nirmatrelvir-ritonavir from Dec 10, 2022, to February 20, 2023, and did not require invasive ventilation support on admission were eligible for inclusion.

RESULTS

After exclusions and propensity-score matching, the final analysis included 486 azvudine recipients and 486 nirmatrelvir-ritonavir recipients. By 28 days of initiation of the antivirus treatment, the crude incidence rate of all-cause death was similar in both types of antivirus treatment (nirmatrelvir-ritonavir group 2.8 events 1000 person-days [95% CI, 2.1-3.6] vs azvudine group 3.4 events/1000 person-days [95% CI, 2.6-4.3], P = 0.38). Landmark analysis showed that all-cause death was lower in the nirmatrelvir-ritonavir (3.5%) group than the azvudine (6.8%, P = 0.029) within the initial 10-day admission period, while no significant difference was observed for results between 10 and 28 days follow-up. There was no significant difference between the nirmatrelvir-ritonavir group and the azvudine group in cumulative incidence of the composite disease progression event (8.6% with nirmatrelvir-ritonavir vs. 10.1% with azvudine, HR, 1.22; 95% CI 0.80-1.86, P = 0.43).

CONCLUSION

Among patients hospitalized with COVID-19 during the omicron wave in Beijing, similar in-hospital clinical outcomes on 28 days were observed between patients receiving nirmatrelvir-ritonavir and azvudine. However, it is worth noticing that nirmatrelvir-ritonavir appears to hold an advantage over azvudine in reducing early mortality. Further randomized controlled trials are needed to verify the efficacy of those two antivirus medications especially in early treatment.

Clinical Risk and Outpatient Therapy Utilization for COVID-19 in the Medicare Population

Importance

Multiple therapies are available for outpatient treatment of COVID-19 that are highly effective at preventing hospitalization and mortality. Although racial and socioeconomic disparities in use of these therapies have been documented, limited evidence exists on what factors explain differences in use and the potential public health relevance of these differences.

Objective

To assess COVID-19 outpatient treatment utilization in the Medicare population and simulate the potential outcome of allocating treatment according to patient risk for severe COVID-19.

Design, Setting, and Participants

This cross-sectional study included patients enrolled in Medicare in 2022 across the US, identified with 100% Medicare fee-for-service claims.

Main Outcomes and Measures

The primary outcome was any COVID-19 outpatient therapy utilization. Secondary outcomes included COVID-19 testing, ambulatory visits, and hospitalization. Differences in outcomes were estimated based on patient demographics, treatment contraindications, and a composite risk score for mortality after COVID-19 based on demographics and comorbidities. A simulation of reallocating COVID-19 treatment, particularly with nirmatrelvir, to those at high risk of severe disease was performed, and the potential COVID-19 hospitalizations and mortality outcomes were assessed.

Results

In 2022, 6.0% of 20 026 910 beneficiaries received outpatient COVID-19 treatment, 40.5% of which had no associated COVID-19 diagnosis within 10 days. Patients with higher risk for severe disease received less outpatient treatment, such as 6.4% of those aged 65 to 69 years compared with 4.9% of those 90 years and older (adjusted odds ratio [aOR], 0.64 [95% CI, 0.62-0.65]) and 6.4% of White patients compared with 3.0% of Black patients (aOR, 0.56 [95% CI, 0.54-0.58]). In the highest COVID-19 severity risk quintile, 2.6% were hospitalized for COVID-19 and 4.9% received outpatient treatment, compared with 0.2% and 7.5% in the lowest quintile. These patterns were similar among patients with a documented COVID-19 diagnosis, those with no claims for vaccination, and patients who are insured with Medicare Advantage. Differences were not explained by variable COVID-19 testing, ambulatory visits, or treatment contraindications. Reallocation of 2022 outpatient COVID-19 treatment, particularly with nirmatrelvir, based on risk for severe COVID-19 would have averted 16 503 COVID-19 deaths (16.3%) in the sample.

Conclusion

In this cross-sectional study, outpatient COVID-19 treatment was disproportionately accessed by beneficiaries at lower risk for severe infection, undermining its potential public health benefit. Undertreatment was not driven by lack of clinical access or treatment contraindications.

Antiviral therapy of coronavirus disease 2019 (COVID-19)

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

Optimal timing of nirmatrelvir/ritonavir treatment after COVID-19 symptom onset or diagnosis: target trial emulation

Reports of symptomatic rebound and/or test re-positivity among COVID-19 patients following the standard five-day treatment course of nirmatrelvir/ritonavir have sparked debates regarding optimal treatment timing and dosage. It is unclear whether initiating nirmatrelvir/ritonavir immediately after symptom onset would improve clinical outcomes and/or lead to post-treatment viral burden rebound due to inadequate viral clearance during treatment. Here we show that, by emulating a randomized target trial using real-world electronic medical record data from all 87,070 adult users of nirmatrelvir/ritonavir in Hong Kong between 16th March 2022 and 15th January 2023, early initiation of nirmatrelvir/ritonavir treatment (0 to 1 days after symptom onset or diagnosis) significantly reduced the incidence of 28-day all-cause mortality and hospitalization compared to delayed initiation (2 or more days) (absolute risk reduction [ARR]: 1.50% (95% confidence interval 1.17-1.80%); relative risk [RR]: 0.77 (0.73, 0.82)), but may be associated with a significant elevated risk of viral burden rebound (ARR: -1.08% (-1.55%, -0.46%)), although the latter estimates were associated with high uncertainty due to limited sample sizes. As such, patients should continue to initiate nirmatrelvir/ritonavir early after symptom onset or diagnosis to better protect against the more serious outcomes of hospitalization and mortality.

Evaluation of the efficacy and safety of nirmatrelvir/ritonavir co-administration inpatients with rheumatic disease infected with SARS-CoV-2: a real-world study

Background: The breakthrough development of novel severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) vaccines and oral antivirals have played a critical role in curtailing the spread of the pandemic and dramatically reducing the morbidity and mortality rates among those infected. Among these oral antivirals, nirmatrelvir/ritonavir (NR) has been repurposed successfully for use against coronavirus disease-2019 (COVID-19) and is now readily available on the market with promising therapeutic effects. The availability of convenient and effective NR treatments for COVID-19 greatly mitigates the severity of the epidemic and contributes to an early end to the pandemic. Furthermore, certain patient subgroups, specifically those with rheumatic disease (RD) who are currently undergoing intensive immunodeficiency and/or immunosuppressive treatments, continue to be vulnerable and at a higher risk of experiencing severe consequences from COVID-19. Additionally, it has also been observed that NR exhibited prevalent drug-drug interactions of clinical significance, and more instances of COVID-19 rebound were being recognized with increasing frequency. Methods: A retrospective cohort study was conducted on a real-world RD population who were infected with SARS-CoV-2 and treated with NR. The time of symptom resolution, length of hospitalization, and response rate were assessed. Results were compared among the standard regimen and non-standard regimen groups, early NR regimen and late NR regimen groups, and the NR indication regimen and NR non-indication regimen groups. During the course, all grades of adverse drug reactions (ADRs) directly associated with NR administration and associated with drug-drug interactions (DDIs) were also monitored. Results: A total of 32 patients with RD, who were infected with SARS-CoV-2 and received NR, were retrospectively identified and divided into different groups. We found that the standard regimen group and the early NR regimen group had a shorter median time of symptom resolution compared to the control group [9.0 (interquartile range [IQR], 8.3-11.3) vs. 21.5 (IQR16.0-24.0) days, p < 0.001 and 9.0 (IQR 8.3-11.3) vs. 23.0 (IQR 18.0-24.0) days, p = 0.0]. We further found that even if the NR administration time exceeds 5 days, patients with RD who receive the NR indication regimen can still derive certain benefits from it. The proportion of patients who showed symptom improvement was higher in the NR indication regimen compared to the NR non-indication regimen group (n = 13/17 vs. 3/6, 76.5% vs. 50.0%) at the end of follow-up, and there was a statistical difference (p = 0.0) in the response rate of patients between the two groups. We also analyzed the effect of comorbidities on patient response rates and found that the percentage of patients who showed symptom improvement was higher in the group with <4 comorbidities compared to the group with ≥ 4 comorbidities (n = 7/7 vs. 16/25, 100.0% vs. 64.0%) at the end of follow-up. During the course, all grades of ADRs and grade ≥3ADRs directly associated with NR administration were not observed in any of the 32 cases. Despite discontinuing warfarin prior to NR application (using NR immediately on the first day of warfarin withdrawal), one patient still experienced an increased international normalized ratio [INR, 5.32(0.90-1.20)] and coagulation disorders (weak positive fecal occult blood test) on the second day after using NR. The INR levels decreased to nearly normal values, and coagulation disorders returned to normal after 2 days of discontinuing NR (the seventh day after the initial administration of NR). Conclusion: We showed NR therapy to be associated with a favorable outcome and an acceptable safety profile in an immunosuppressed population with RD during the Omicron surge. Early use of NR (within 5 days of symptom onset) could improve the prognosis of patients. NR administration for symptoms and confirmed SARS-CoV-2 infection after >5 days may also mitigate progression to severe disease and is a viable strategy. Our results highlight the importance of early utilization and/or NR indication, which may yield clinical advantages for patients with RD infected with SARS-CoV-2.

Small-molecule anti-COVID-19 drugs and a focus on China's homegrown mindeudesivir (VV116)

The coronavirus disease 2019 (COVID-19) pandemic has stimulated tremendous efforts to develop therapeutic agents that target severe acute respiratory syndrome coronavirus 2 to control viral infection. So far, a few small-molecule antiviral drugs, including nirmatrelvir-ritonavir (Paxlovid), remdesivir, and molnupiravir have been marketed for the treatment of COVID-19. Nirmatrelvir-ritonavir has been recommended by the World Health Organization as an early treatment for outpatients with mild-to-moderate COVID-19. However, the existing treatment options have limitations, and effective treatment strategies that are cost-effective and convenient for tackling COVID-19 are still needed. To date, four domestically developed oral anti-COVID-19 drugs have been granted conditional market approval in China. These drugs include azvudine, simnotrelvir-ritonavir (Xiannuoxin), leritrelvir, and mindeudesivir (VV116). Preclinical and clinical studies have explored the efficacy and tolerability of mindeudesivir and supported its early use in mild-to-moderate COVID-19 cases at high risk for progression. In this review, we discuss the most recent findings regarding the pharmacological mechanism and therapeutic effects focusing on mindeudesivir and other small-molecule antiviral agents for COVID-19. These findings will expand our understanding and highlight the potential widespread application of China's homegrown anti-COVID-19 drugs.

Association between nirmatrelvir plus ritonavir and the outcomes of non-hospitalized obese patients with COVID-19

OBJECTIVE

To investigate the association between nirmatrelvir plus ritonavir (NMV-r) and the outcomes of non-hospitalized obese patients with coronavirus disease 2019 (COVID-19).

METHODS

This retrospective cohort study used the TriNetX research network to identify non-hospitalized obese adult patients with COVID-19 between 1 January 2022 and 30 June 2023. Propensity score matching was used to match patients receiving NMV-r (NMV-r group) with those not receiving NMV-r (control group). The primary outcome was the compositive outcome of all-cause emergency department (ED) visits, hospitalization or death during the 30-day follow-up period.

RESULTS

Using propensity score matching methods, two cohorts of 30,969 patients each with balanced baseline characteristics were identified. During the follow-up period, the NMV-r group had a lower risk of all-cause ED visits, hospitalization or death [4.80% (n=1489) vs 5.50% (n=1705); hazard ratio (HR) 0.900, 95% confidence interval (CI) 0.839-0.965]. Compared with the control group, the NMV-r group had a lower risk of all-cause ED visits (HR 0.812, 95% CI 0.740-0.891) and all-cause mortality (HR 0.089, 95% CI 0.027-0.288). The lower risk in the NMV-r group compared with the control group was observed consistently in most subgroup analyses according to body mass index (30.0-34.9 kg/m2: HR 0.68, 95% CI 0.55-0.82; 35.0-39.9 kg/m2: HR 0.67, 95% CI 0.52-0.87), age (4-64 years: HR 0.83, 95% CI 0.75-0.92; ≥65 years: HR 0.88, 95% CI 0.79-0.98), sex (men: HR 0.69, 95% CI 0.60-0.79; women: HR 0.69, 95% CI 0.63-0.76) and vaccination status (unvaccinated: HR 0.75, 95% CI 0.70-0.81).

CONCLUSION

NMV-r is associated with reduced risk of all-cause ED visits, hospitalization and death for non-hospitalized obese patients with COVID-19. Accordingly, these findings support the use of NMV-r in obese patients.

Budget impact of oral nirmatrelvir/ritonavir in adults at high risk for progression to severe COVID-19 in the United States

BACKGROUND

Nirmatrelvir/ritonavir (NMV/r) is indicated for the treatment of mild-to-moderate COVID-19 in adults who are at high risk for progression to severe COVID-19. NMV/r has also been authorized for emergency use by the US Food and Drug Administration for the treatment of mild-to-moderate COVID-19 in pediatric patients (aged 226512 years and weighing at least 40 kg) who are at high risk for progression to severe COVID-19. Understanding the budget impact of introducing NMV/r for the treatment of adults with COVID-19 is of key interest to US payers.

OBJECTIVE

To estimate the annual budget impact of introducing NMV/r in a US commercial health plan setting in the current Omicron COVID-19 era.

METHODS

A budget impact model was developed to assess the impact of NMV/r on health care costs in a hypothetical 1-million-member commercial health insurance plan over a 1-year period in the US population; clinical and cost inputs were derived from published literature with a focus on studies in the recent COVID-19 era that included vaccinated population and predominance of the Omicron variant. In the base-case analysis, it was assumed the only effect of NMV/r was a reduction in incidence (not severity) of hospitalization or death; its potential effect on post-COVID conditions was assessed in a scenario analysis. Outcomes included the number of hospitalizations, total cost, per patient per year (PPPY) costs, and per member per month (PMPM) costs. Sensitivity and scenario analyses were conducted to assess uncertainty around key model inputs.

RESULTS

An estimated 29,999 adults were eligible and sought treatment with oral antiviral for COVID-19 over 1 year. The availability of NMV/r was estimated to reduce the number of hospitalizations by 647 with a total budget impact of $2,733,745, $91 PPPY, and $0.23 PMPM. NMV/r was cost saving when including post-COVID conditions with a -$1,510,780 total budget impact, a PPPY cost of -$50, and a PMPM cost of -$0.13. Sensitivity analyses indicated results were most sensitive to the risk of hospitalization under supportive care, risk of hospitalization with NMV/r treatment and cost of NMV/r.

CONCLUSIONS

Treatment with NMV/r in the current COVID-19 era is estimated to result in substantial cost offsets because of reductions in hospitalization and modest budget impact to potential overall cost savings.

Effectiveness of Nirmatrelvir-Ritonavir Against the Development of Post-COVID-19 Conditions Among U.S. Veterans : A Target Trial Emulation

BACKGROUND

COVID-19 has been linked to the development of many post-COVID-19 conditions (PCCs) after acute infection. Limited information is available on the effectiveness of oral antivirals used to treat acute COVID-19 in preventing the development of PCCs.

OBJECTIVE

To measure the effectiveness of outpatient treatment of COVID-19 with nirmatrelvir-ritonavir in preventing PCCs.

DESIGN

Retrospective target trial emulation study comparing matched cohorts receiving nirmatrelvir-ritonavir versus no treatment.

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 treatment for acute COVID-19.

MEASUREMENTS

Cumulative incidence of 31 potential PCCs at 31 to 180 days after treatment or a matched index date, including cardiac, pulmonary, renal, thromboembolic, gastrointestinal, neurologic, mental health, musculoskeletal, endocrine, and general conditions and symptoms.

RESULTS

Eighty-six percent of the participants were male, with a median age of 66 years, and 17.5% were unvaccinated. Baseline characteristics were well balanced between participants treated with nirmatrelvir-ritonavir and matched untreated comparators. No differences were observed between participants treated with nirmatrelvir-ritonavir (n = 9593) and their matched untreated comparators in the incidence of most PCCs examined individually or grouped by organ system, except for lower combined risk for venous thromboembolism and pulmonary embolism (subhazard ratio, 0.65 [95% CI, 0.44 to 0.97]; cumulative incidence difference, -0.29 percentage points [CI, -0.52 to -0.05 percentage points]).

LIMITATIONS

Ascertainment of PCCs using International Classification of Diseases, 10th Revision, codes may be inaccurate. Evaluation of many outcomes could have resulted in spurious associations with combined thromboembolic events by chance.

CONCLUSION

Out of 31 potential PCCs, only combined thromboembolic events seemed to be reduced by nirmatrelvir-ritonavir.

PRIMARY FUNDING SOURCE

U.S. Department of Veterans Affairs.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Oral Molnupiravir and Nirmatrelvir/Ritonavir for the Treatment of COVID-19: A Literature Review with a Focus on Real-World Evidence

Vaccines remain the cornerstone of medical prevention and are highly effective in reducing the risk of severe disease and death due to coronavirus disease 2019 (COVID-19). In the context of expanding the therapeutic armamentarium against COVID-19, molnupiravir (Lagevrio) and ritonavir-boosted nirmatrelvir (Paxlovid) were developed, constituting the first effective oral treatments against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In this narrative review, we retrospectively inquired into the clinical trials and real-world studies investigating the efficacy of these agents. Overall, clinical trials and real-world studies have demonstrated the efficacy of both agents in reducing hospitalization and death rates in COVID-19 patients. As per current recommendations, their use is suggested in patients with mild to moderate symptoms who are at high risk of developing severe disease. Nevertheless, limited data exist regarding their efficacy in specific subpopulations, such as immunocompromised patients, those with severe kidney disease, pregnant women, and children.

EuCARE-hospitalised study protocol: a cohort study of patients hospitalised with COVID-19 in the EuCARE project

BACKGROUND

Severe acute respiratory syndrome coronavirus 2 (SARS CoV-2), the virus responsible for coronavirus disease 2019 (COVID-19), can lead to hospitalisation, particularly in elderly, immunocompromised, and non-vaccinated or partially vaccinated individuals. Although vaccination provides protection, the duration of this protection wanes over time. Additional doses can restore immunity, but the influence of viral variants, specific sequences, and vaccine-induced immune responses on disease severity remains unclear. Moreover, the efficacy of therapeutic interventions during hospitalisation requires further investigation. The study aims to analyse the clinical course of COVID-19 in hospitalised patients, taking into account SARS-CoV-2 variants, viral sequences, and the impact of different vaccines. The primary outcome is all-cause in-hospital mortality, while secondary outcomes include admission to intensive care unit and length of stay, duration of hospitalisation, and the level of respiratory support required.

METHODS

This ongoing multicentre study observes hospitalised adult patients with confirmed SARS-CoV-2 infection, utilising a combination of retrospective and prospective data collection. It aims to gather clinical and laboratory variables from around 35,000 patients, with potential for a larger sample size. Data analysis will involve biostatistical and machine-learning techniques. Selected patients will provide biological material. The study started on October 14, 2021 and is scheduled to end on October 13, 2026.

DISCUSSION

The analysis of a large sample of retrospective and prospective data about the acute phase of SARS CoV-2 infection in hospitalised patients, viral variants and vaccination in several European and non-European countries will help us to better understand risk factors for disease severity and the interplay between SARS CoV-2 variants, immune responses and vaccine efficacy. The main strengths of this study are the large sample size, the long study duration covering different waves of COVID-19 and the collection of biological samples that allows future research.

TRIAL REGISTRATION

The trial has been registered on ClinicalTrials.gov. The unique identifier assigned to this trial is NCT05463380.

Comparison between available early antiviral treatments in outpatients with SARS-CoV-2 infection: a real-life study

PURPOSE

To investigate the clinical impact of three available antivirals for early COVID-19 treatment in a large real-life cohort.

METHODS

Between January and October 2022 all outpatients tested positive for SARS-CoV-2 referring to IRCCS S. Orsola hospital treated with an early antiviral therapy were enrolled. A comparison between patients treated with nirmatrelvir/ritonavir (NTV/r), molnupiravir (MPV) and remdesivir (RDV) was conducted in term of indications and outcome. To account for differences between treatment groups a propensity score analysis was performed. After estimating the weights, we fitted a survey-weighted Cox regression model with inverse-probability weighting with hospital admission/death versus clinical recovery as the primary outcome.

RESULTS

Overall 1342 patients were enrolled, 775 (57.8%), 360 (26.8%) and 207 (15.4%) in MPV, NTV/r and RDV group, respectively. Median age was 73 (59-82) years, male sex was 53.4%. Primary indication was immunosuppression (438, 32.6%), the median time from symptom onset to drug administration was 3 [2-4] days. Overall, clinical recovery was reached in 96.9% of patients, with hospital admission rate of 2.6%. No significant differences were found in clinical recovery nor hospitalization. Cox regression showed a decreased probability of hospital admission/ death among prior vaccinated patients compared with unvaccinated (HR 0.31 [95%CI 0.14-0.70], p = 0.005]). No difference in hospitalization rates in early treatment compared to late treatment were found.

CONCLUSIONS

No differences among MPV, NTV/r and RDV in terms of clinical recovery or hospitalization were found. Patients not vaccinated had a significant increased risk of hospitalization.

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

Background

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

Methods

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

Findings

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

Interpretation

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

Funding

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

Real-world effectiveness of nirmatrelvir/ritonavir against COVID-19 hospitalizations and severe COVID-19 in community-dwelling elderly Singaporeans during Omicron BA.2, BA.4/5, and XBB transmission

OBJECTIVES

Real-world data on continued effectiveness of nirmatrelvir/ritonavir against hospitalization and severe COVID-19 in the context of widespread booster mRNA vaccine uptake and more immune-evasive Omicron sub-variants are lacking. We conducted a retrospective cohort study in adult Singaporeans aged ≥60 years presenting to primary care with SARS-CoV-2 infection, during waves of Omicron BA.2/4/5/XBB transmission.

METHODS

Binary logistic regression was used to estimate the effect of treatment (receiving nirmatrelvir/ritonavir) on outcomes (hospitalization, severe COVID-19). Additional sensitivity analyses, including inverse-probability-of-treatment-weighting-adjusted analysis and adjustment using overlap weights, were performed to account for observed differences in baseline characteristics among treated/untreated cohorts.

RESULTS

We included 3959 nirmatrelvir/ritonavir recipients and 139 379 untreated controls. Almost 95% received ≥3 doses of mRNA vaccines; 5.4% had preceding infection. Overall 26.5% of infections occurred during the Omicron XBB period and 1.7% were hospitalized. On multivariable logistic regression, receipt of nirmatrelvir/ritonavir was independently associated with lower odds of hospitalization (adjusted odds ratio [aOR] = 0.65, 95% CI = 0.50-0.85). Consistent estimates were obtained after inverse-probability-of-treatment-weighting adjustment (aOR for hospitalization = 0.60, 95% CI = 0.48-0.75) and adjustment using overlap weights (aOR for hospitalization = 0.64, 95% CI = 0.51-0.79). Although receipt of nirmatrelvir/ritonavir was associated with lower odds of severe COVID-19, it was not statistically significant.

DISCUSSION

Outpatient usage of nirmatrelvir/ritonavir was independently associated with reduced odds of hospitalization amongst boosted older community-dwelling Singaporeans during successive waves of Omicron transmission, including Omicron XBB; however, it did not significantly reduce the already low risk of severe COVID-19 in a highly vaccinated population.

Outpatient Treatment of Confirmed COVID-19: Living, Rapid Practice Points From the American College of Physicians (Version 2)

DESCRIPTION

Evidence for the use of outpatient treatments in adults with confirmed COVID-19 continues to evolve with new data. This is version 2 of the American College of Physicians (ACP) living, rapid practice points focusing on 22 outpatient treatments for COVID-19, specifically addressing the dominant SARS-CoV-2 Omicron variant.

METHODS

The Population Health and Medical Science Committee (formerly the Scientific Medical Policy Committee) developed this version of the living, rapid practice points on the basis of a living, rapid review done by the ACP Center for Evidence Reviews at Cochrane Austria at the University for Continuing Education Krems (Danube University Krems). This topic will be maintained as living and rapid by continually monitoring and assessing the impact of new evidence.

PRACTICE POINT 1

Consider molnupiravir to treat symptomatic patients with confirmed mild to moderate COVID-19 in the outpatient setting who are within 5 days of the onset of symptoms and at a high risk for progressing to severe disease.

PRACTICE POINT 2

Consider nirmatrelvir-ritonavir combination therapy to treat symptomatic patients with confirmed mild to moderate COVID-19 in the outpatient setting who are within 5 days of the onset of symptoms and at a high risk for progressing to severe disease.

PRACTICE POINT 3

Do not use ivermectin to treat patients with confirmed mild to moderate COVID-19 in the outpatient setting.

PRACTICE POINT 4

Do not use sotrovimab to treat patients with confirmed mild to moderate COVID-19 in the outpatient setting.

Outpatient Treatment of Confirmed COVID-19: A Living, Rapid Evidence Review for the American College of Physicians (Version 2)

BACKGROUND

Clinicians and patients want to know the benefits and harms of outpatient treatment options for the Omicron variant of SARS-CoV-2.

PURPOSE

To assess the benefits and harms of 22 different COVID-19 treatments.

DATA SOURCES

The Epistemonikos COVID-19 L·OVE platform, the iSearch COVID-19 portfolio, and the World Health Organization (WHO) COVID-19 Research Database from 26 November 2021 to 2 March 2023.

STUDY SELECTION

Two reviewers independently screened abstracts and full texts against a priori-defined criteria.

DATA EXTRACTION

One reviewer extracted the data and assessed the risk of bias and certainty of evidence (COE). A second reviewer verified the data abstraction and assessments.

DATA SYNTHESIS

Two randomized controlled trials and 6 retrospective cohort studies were included. Nirmatrelvir-ritonavir was associated with a reduction in hospitalization due to COVID-19 (for example, 0.7% vs. 1.2%; moderate COE) and all-cause mortality (for example, <0.1% vs. 0.2%; moderate COE). Molnupiravir led to a higher recovery rate (31.8% vs. 22.6%; moderate COE) and reduced time to recovery (9 vs. 15 median days; moderate COE) but had no effect on all-cause mortality (0.02% vs. 0.04%; moderate COE) and the incidence of serious adverse events (0.4% vs. 0.3%; moderate COE). Ivermectin had no effect on time to recovery (moderate COE) and resulted in no difference in adverse events compared with placebo (low COE). Sotrovimab resulted in no difference in all-cause mortality compared with no treatment (low COE). No eligible studies for all other treatments of interest were identified.

LIMITATION

Evidence for nirmatrelvir-ritonavir and sotrovimab is based on nonrandomized studies only.

CONCLUSION

Nirmatrelvir-ritonavir and molnupiravir probably improve outcomes for outpatients with mild to moderate COVID-19.

PRIMARY FUNDING SOURCE

American College of Physicians. (PROSPERO: CRD42023406456).

Real-world nirmatrelvir-ritonavir outpatient treatment in reducing hospitalization for high-risk patients with COVID-19 during Omicron BA.4, BA.5 and XBB subvariants dominance in Malaysia: A retrospective cohort study

OBJECTIVE

To determine if nirmatrelvir-ritonavir 300mg/100mg treatment for 5 days in high-risk outpatients with mild to moderate COVID-19 symptoms was associated with a reduction in hospitalization, intensive care unit (ICU) admission, and death.

METHODS

This 1:1 propensity score matched cohort study from 647 public health clinics in Malaysia included all patients with COVID-19 with positive tests aged 18 years and older, who were eligible for nirmatrelvir-ritonavir treatment within 5 days of illness from July 14, 2022, to November 14, 2022. The exposed group was patients with COVID-19 initiated with nirmatrelvir-ritonavir treatment, whereas those not initiated with the drug served as the control group. Data was analyzed from July 14, 2022 to December 31, 2022.

RESULTS

A total of 20,966 COVID-19 high-risk outpatients (n = 10,483 for nirmatrelvir-ritonavir group and n = 10,483 for control group) were included in the study. Nirmatrelvir-ritonavir treatment was associated with a 36% reduction (adjusted hazard ratio 0.64 [95% CI 0.43, 0.94]) in hospitalization compared with those not given the drug. There was a single ICU admission for the control group and one death each was reported in the nirmatrelvir-ritonavir and control group, respectively.

CONCLUSIONS

Nirmatrelvir-ritonavir treatment was associated with reduced hospitalization in high-risk patients with COVID-19 even in highly vaccinated populations.

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.

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.

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.

Nirmatrelvir-ritonavir use among adults hospitalized with COVID-19 during the Omicron phase of the COVID-19 pandemic, Canadian Nosocomial Infection Surveillance Program

Background

Recent studies have demonstrated the effectiveness of nirmatrelvir-ritonavir in reducing the risk of progression to severe disease among outpatients with mild to moderate coronavirus disease 2019 (COVID-19); however, data are limited regarding the use and role of nirmatrelvir-ritonavir among hospitalized patients. This study describes the use and outcomes of nirmatrelvir-ritonavir among adults hospitalized with COVID-19 in a sentinel network of Canadian acute care hospitals during the Omicron variant phase of the pandemic.

Methods

The Canadian Nosocomial Infection Surveillance Program conducts surveillance of hospitalized patients with COVID-19 in acute care hospitals across Canada. Demographic, clinical, treatment and 30-day outcome data were collected by chart review by trained infection control professionals using standardized questionnaires.

Results

From January 1 to December 31, 2022, 13% (n=490/3,731) of adult patients (18 years of age and older) hospitalized with COVID-19 in 40 acute care hospitals received nirmatrelvir-ritonavir either at admission or during hospitalization. Most inpatients who received nirmatrelvir-ritonavir, 79% of whom were fully vaccinated, had at least one pre-existing comorbidity (97%) and were of advanced age (median=79 years). Few were admitted to an intensive care unit (2.3%) and among the 490 nirmatrelvir-ritonavir treated inpatients, there were 13 (2.7%) deaths attributable to COVID-19.

Conclusion

These findings from a large sentinel network of Canadian acute-care hospitals suggest that nirmatrelvir-ritonavir is being used to treat adult COVID-19 patients at admission who are at risk of progression to severe disease or those who acquired COVID-19 in hospital. Additional research on the efficacy and indications for nirmatrelvir-ritonavir use in hospitalized patients is warranted to inform future policies and guidelines.