Effectiveness of nirmatrelvir-ritonavir for the treatment of patients with mild to moderate COVID-19 and at high risk of hospitalization: Systematic review and meta-analyses of observational studies

Cost-effectiveness of outpatient COVID-19 antiviral treatment with nirmatrelvir/ritonavir versus usual care in Swedish patients with various risk factors

AIMS

Nirmatrelvir/ritonavir (NMV/r) is an orally administered antiviral indicated for the outpatient treatment of adult 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 54 patient cohorts, specified according to age, vaccination status and comorbidity burden.

MATERIALS AND METHODS

A previously published and validated cost-effectiveness model was utilized and adapted to the Swedish setting. The model used a short-term decision-tree (1 year) followed by a lifetime 2-state Markov model. The short-term decision-tree captured costs and outcomes associated with the primary infection. Post-acute COVID-19 syndrome was only considered in terms of quality-of-life decrements for one year. Baseline hospitalization and mortality risks were taken from a Swedish, nationwide, uniquely granular, Omicron-era, real-world study. 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 Swedish sources.

RESULTS

The incremental cost-effectiveness ratios (ICERs) showed a large variation ranging from almost nine million SEK for some of the youngest cohorts to being dominant (i.e. cost-saving with higher gains in quality-of-life vs standard of care) for twelve elderly cohorts. In general, higher age in combination with non-recent (>180 days) or no vaccination led to lower ICERs. Specifically, NMV/r was cost-effective for all but one patient cohorts at least 70 years old, and for most patient cohorts 60-69 years old.

LIMITATIONS

As the COVID-19 landscape changes, symptom burden and baseline risks constantly change. Thus, the cost-effectiveness of NMV/r will change with time. However, the future risks could be related to the risks in the current study, and thus remain useful for decision makers.

CONCLUSIONS

This study shows that NMV/r is a cost-effective or even cost-saving treatment option for many patient cohorts, including most elderly and not-recently vaccinated patients with at least some comorbidity burden.

Patient Experiences With Nirmatrelvir/Ritonavir for COVID-19 in a Collaborative Care Model: A Cross-Sectional Study on Self-Management, Information, and Medication Impact

In response to the COVID-19 pandemic, nirmatrelvir/ritonavir was approved as the first per os treatment to prevent severe disease progression. This study explores patients' self-management of nirmatrelvir/r and its impact on their long-term medications, and their experience of the information provided by pharmacists and physicians. Adults receiving nirmatrelvir/r from September 2022 to March 2023 were interviewed via a semistructured telephone survey. Sociodemographic, clinical data, and experience with nirmatrelvir/r and cotreatments were collected and analyzed descriptively. Of the 281 patients receiving nirmatrelvir/r, 100 (36%) participated in this study. Ninety (90%) adhered to nirmatrelvir/r, while 5 (5%) reported early discontinuation and 5 (5%) increased time between dosages. Information gaps regarding side effects, risks, benefits, and mechanisms of action were identified. Due to interactions with nirmatrelvir/r, 43% (n = 43/85) of cotreatments were temporarily interrupted, and 13% (n = 11/85) of doses were adjusted. Patient management of nirmatrelvir/r and cotreatments was successful, but satisfaction toward nirmatrelvir/r information could be improved. This study highlights the importance of ongoing efforts to ensure communication strategies, patient education, and interprofessional collaboration in providing treatments with drug-drug interactions.

Cost-effectiveness of nirmatrelvir/ritonavir in COVID-19 patient groups at high risk for progression to severe COVID-19 in the Netherlands

BACKGROUND

Nirmatrelvir/ritonavir is indicated for the treatment of COVID-19 in symptomatic adults with increased risk for severe illness, not requiring supplemental oxygen yet. From a Dutch societal perspective, a cost-utility assessment of nirmatrelvir/ritonavir versus best supportive care (BSC) was conducted in three patient groups: (a) immunocompromised patients, (b) patients aged at least 60 years with one comorbidity, (c) patients aged at least 70 years. Groups were selected considering their relevance as high-risk groups, as described in Dutch and international guidelines and recommendations.

METHODS

A one-year decision-tree, estimating costs and outcomes associated with a COVID-19 infection was coupled to a lifetime two-state Markov component simulating subsequent life-time survival and quality of life. Effectiveness estimates, informing the intervention preventing hospital admission or death, were based on real-world evidence by Lewnard and colleagues (2023) in a vaccinated population during a timeframe with predominance of the Omicron variant. Epidemiology relies on publicly available data, primarily sourced during the Omicron variant's era. In the decision tree, clinically relevant event-related disutilities per disease course were applied to adjusted age-dependent Dutch-specific utility levels. In the Markov component, a disutility was considered for post-ICU patients. Costs rely on Dutch pharmacoeconomic guidelines and public data sources. The incremental cost-effectiveness ratio (ICER) was analysed as the main outcome, with a positive ICER indicating the cost associated with each additional quality-adjusted life year (QALY) gained by adopting the intervention.

RESULTS

Nirmatrelvir/ritonavir was associated with an ICER of € 395 in the immunocompromised group (per patient: + 0.125 QALYs gained; + 0.130 life-years [LYs] gained; € 49 incremental cost), with an ICER of € 8700 in 60-plus patients with comorbidity (+ 0.054 QALYs; + 0.055 LYs; € 474 incremental cost), and with an ICER of € 13,021 among 70-plus patients (+ 0.053 QALYs; + 0.045 LYs; € 689 incremental cost). Results were most sensitive to the baseline hospitalization rates among high-risk individuals. Probabilistic sensitivity analyses indicate a high probability of being cost-effective (100, 94, 85% respectively), considering a willingness-to-pay threshold of € 20,000 per QALY.

CONCLUSIONS

From a Dutch societal perspective, over a lifetime horizon, nirmatrelvir/ritonavir is cost-effective versus BSC in the three groups analysed.

Open Innovation or Traditional Patenting Strategies to Efficiently Address Health Emergencies: How Patent Information was used Towards Effective Treatments for COVID-19

INTRODUCTION/OBJECTIVE

During the 1150 days of COVID-19 pandemic there were great efforts to develop efficient treatments for the disease. After this long time, some drugs emerged as treatment for COVID-19. Some of them are new drugs, most of them, known drugs. These developments were triggered by information already available in patent documents. Pharmaceutical companies, therefore, rushed to conduct drugs evaluations and trials in order to deliver to the world a reasonable treatment that could reach the majority of its population. However, it is not immediately clear how companies operated to reach their goals. The ability of open innovation to achieve results assertively and faster than closed innovation strategies is questioned and therefore, it is questioned whether pharmaceutical companies use open innovation to face COVID-19.

METHODS

In this work, data available on patent databases were mined to inform about the scientific and technological panorama of selected drugs tested for COVID-19 treatment and to understand the perspectives of such developments during the pandemic.

RESULTS

This study evidenced that most treatments were based on known drugs, that some of the initially promising drugs were abandoned during the pandemic, and that it was able to inform if open innovation and collaborations were explored strategies.

CONCLUSION

This study evidenced that the developments during COVID-19 were not based on open innovation by revealing a patent race towards the treatment development, but with practically no collaborations or information exchange between companies, universities, and research facilities.

Nationwide Target Trial Emulation Evaluating the Clinical Effectiveness of Oral Antivirals for COVID-19 in Korea

BACKGROUND

Despite the proven effectiveness of oral antivirals against severe acute respiratory syndrome coronavirus 2 in randomized trials, their clinical reevaluation is vital in the context of widespread immunity and milder prevalent variants. This study aimed to assess the effectiveness of oral antivirals for coronavirus disease 2019 (COVID-19).

METHODS

This retrospective cohort study utilized a target trial emulation framework to analyze patients with COVID-19 aged 60+ from January to December 2022. Data were obtained from the Korea Disease Control and Prevention Agency and Health Insurance Review and Assessment Service. The study involved 957,036 patients treated with nirmatrelvir/ritonavir and 243,360 treated with molnupiravir, each compared with the matched control groups. Primary outcome was progression to critical COVID-19 requiring advanced respiratory support. Secondary outcomes included progression to severe COVID-19, need for supplemental oxygen, and death within 30 days of the onset of COVID-19. Number needed to treat (NNT) derived from the absolute risk reduction.

RESULTS

Nirmatrelvir/ritonavir was significantly associated with a reduced risk of severe (adjusted odds ratio [aOR], 0.823; 95% confidence interval [CI], 0.803-0.843), critical (aOR, 0.560; 95% CI, 0.503-0.624), and fatal COVID-19 (aOR, 0.694; 95% CI, 0.647-0.744). Similarly, molnupiravir reduced the risk of severe (aOR, 0.895; 95% CI, 0.856-0.937), critical (aOR, 0.672; 95% CI, 0.559-0.807), and fatal cases (aOR, 0.679; 95% CI, 0.592-0.779). NNTs for nirmatrelvir/ritonavir were 203.71 (severe), 1,230.12 (critical), and 691.50 (death); for molnupiravir, they were 352.70 (severe), 1,398.62 (critical), and 862.98 (death). Higher effectiveness was associated with older adults, unvaccinated individuals, and the late pandemic phase.

CONCLUSION

Nirmatrelvir/ritonavir and molnupiravir are effective in preventing progression to severe disease in elderly adults with COVID-19.

A Phase III Randomized Controlled Trial of Plitidepsin, a Marine-Derived Compound, in Hospitalized Adults With Moderate COVID-19

BACKGROUND

Plitidepsin has shown potent preclinical activity against severe acute respiratory syndrome coronavirus 2 and was generally well tolerated in a phase I trial of hospitalized patients with coronavirus disease 2019 (COVID-19). NEPTUNO, a phase III, multicenter, randomized, controlled trial, was designed to evaluate the efficacy and safety of plitidepsin in the management of moderate COVID-19 in hospitalized adult patients.

METHODS

Included patients had documented severe acute respiratory syndrome coronavirus 2 infection, required oxygen therapy, and had adequate organ function. The planned sample size was 609 patients. Patients were randomized 1:1:1 to at least 3 days of dexamethasone plus either plitidepsin (1.5 mg/day or 2.5 mg/day, for 3 days) or standard of care (control). The primary endpoint was the time to sustained withdrawal of supplemental oxygen. Secondary endpoints included time to sustained hospital discharge, clinical status, duration of oxygen support, percentage of patients requiring admission to the intensive care unit, and safety.

RESULTS

After randomizing 205 patients, NEPTUNO was discontinued due to a notable drop in COVID-19-related hospitalizations. Available data suggest a 2-day improvement in the median time to sustained oxygen therapy discontinuation (5 vs 7 days) favoring both plitidepsin arms (hazard ratio, 1.37; 95% confidence interval, .96-1.96; P = .08 for plitidepsin 1.5 mg vs control; hazard ratio, 1.06; 95% confidence interval, .73-1.53; P = .78 for plitidepsin 2.5 mg vs control). Plitidepsin was generally well tolerated.

CONCLUSIONS

Despite the trial limitations, these results suggest that plitidepsin may have a positive benefit-risk ratio in the management of patients requiring oxygen therapy. Further studies with plitidepsin, including those in immunosuppressed patients, are warranted.Results from this phase III trial suggest that plitidepsin, a first-in-class antiviral, may have a positive benefit-risk ratio in the management of hospitalized patients requiring oxygen therapy for moderate COVID-19.

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.

Cardiovascular Drug Interactions with Nirmatrelvir/Ritonavir for COVID-19: Considerations for Daily Practice

Cardiovascular disease is associated with progression to severe COVID-19 and patients with the condition are among those in whom early antiviral therapy should be warranted. The combination of nirmatrelvir/ritonavir (Paxlovid®) has been approved for clinical use by the Food and Drug Administration and European Medicines Agency. Because patients with cardiovascular disease are often on polypharmacy, physicians need to be aware of potential drug-drug interactions (DDIs) when treating COVID-19 with nirmatrelvir/ritonavir. Guidance is given for avoiding DDIs, emphasising that preventing and managing potential DDIs with nirmatrelvir/ritonavir requires thorough assessment and knowledge. The present review summarises the clinical pharmacology of nirmatrelvir/ritonavir and provides details on potential DDIs with a focus on daily practice in patients with cardiovascular disease. Particular attention is needed for drugs that are predominantly metabolised by cytochrome P450 3A4, are substrates of P-glycoprotein and have a narrow therapeutic index. Proper management of potential DDIs must balance the benefit of nirmatrelvir/ ritonavir to prevent severe disease with the risk of serious adverse events.

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.

Nirmatrelvir/Ritonavir Regimen for Mild/Moderately Severe COVID-19: A Rapid Review With Meta-Analysis and Trial Sequential Analysis

BACKGROUND

The efficacy, effectiveness, and safety of the approved nirmatrelvir/ritonavir regimen for treatment of laboratory-confirmed mild/moderately severe COVID-19 remains unclear.

METHODS

We systematically identified randomized controlled trials (RCTs) and real-world studies (RWS; observational studies) of the efficacy/effectiveness and/or safety of the approved nirmatrelvir/ritonavir regimen for COVID-19. We pooled appropriate data (adjusted estimates for RWS) using an inverse variance, random-effects model. We calculated statistical heterogeneity using the I 2 statistic. Results are presented as relative risk (RR) with associated 95% CI. We further assessed risk of bias/study quality and conducted trial sequential analysis of the evidence from RCTs.

RESULTS

We included 4 RCTs (4,070 persons) and 16 RWS (1,925,047 persons) of adults (aged ≥18 years). One and 3 RCTs were of low and unclear risk of bias, respectively. The RWS were of good quality. Nirmatrelvir/ritonavir significantly decreased COVID-19 hospitalization compared with placebo/no treatment (RR = 0.17; 95% CI, 0.10-0.31; I 2 = 77.2%; 2 RCTs, 3,542 persons), but there was no significant difference for decrease of worsening severity (RR = 0.82; 95% CI, 0.66-1.01; I 2 = 47.5%; 3 RCTs, 1,824 persons), viral clearance (RR = 1.19; 95% CI, 0.93-1.51; I 2 = 82%; 2 RCTs, 528 persons), adverse events (RR = 1.41; 95% CI, 0.92-2.14; I 2 = 70.6%; 4 RCTs, 4,070 persons), serious adverse events (RR = 0.82; 95% CI, 0.41-1.62; I 2 = 0%; 3 RCTs, 3,806 persons), and all-cause mortality (RR = 0.27; 95% CI, 0.04-1.70; I 2 = 49.9%; 3 RCTs, 3,806 persons), although trial sequential analysis suggested that the current total sample sizes for these outcomes were not large enough for conclusions to be drawn. Real-world studies also showed significantly decreased COVID-19 hospitalization (RR = 0.48; 95% CI, 0.37-0.60; I 2 = 95.0%; 11 RWS, 1,421,398 persons) and all-cause mortality (RR = 0.24; 95% CI, 0.14-0.34; I 2 = 65%; 7 RWS, 286,131 persons) for nirmatrelvir/ritonavir compared with no treatment.

CONCLUSIONS

Nirmatrelvir/ritonavir appears to be promising for preventing hospitalization and potentially decreasing all-cause mortality for persons with mild/moderately severe COVID-19, but the evidence is weak. More studies are needed.

Effectiveness and safety of azvudine in COVID-19: A systematic review and meta-analysis

OBJECTIVE

The aim of this study was to assess the effectiveness and safety of azvudine in treating coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-COV-2).

METHODS

A search was carried out in PubMed, Cochrane Library, Web of Science, medRxiv, and Google Scholar until October 20, 2023. The Cochrane risk of bias tools were used to assess the quality of included studies. Comprehensive Meta-Analysis software was used to analyze data.

RESULTS

Twenty-one studies including 10,011 patients were examined. The meta-analysis results showed that azvudine and standard of care/placebo (SOC/PBO) were significantly different concerning mortality rate (risk ratio [RR] = 0.48, 95% confidence interval [CI]: 0.40 to 0.57) and negative polymerase chain reaction (PCR) conversion time (standard mean difference = - 0.75, 95% CI: -1.29 to-0.21). However, the two groups did not show significant differences concerning hospital stay, intensive care unit (ICU) admission, and need for mechanical ventilation (P > 0.05). On the other hand, azvudine and nirmatrelvir-ritonavir were significantly different in mortality rate (RR = 0.73, 95% CI: 0.58 to 0.92), ICU admission (RR = 0.41, 95% CI: 0.21 to 0.78), and need for mechanical ventilation (RR = 0.67, 95% CI: 0.51 to 0.89), but the two treatments were not significantly different in negative PCR conversion time, and hospital stay (P > 0.05). The incidence of adverse events between groups was not significant (P > 0.05). The certainty of evidence was rated as low or moderate.

CONCLUSIONS

The antiviral effectiveness of azvudine against SARS-COV-2 is questionable with regard to the certainty of evidence. Further research should be conducted to establish the effectiveness and safety of azvudine in COVID-19.

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.