Safety Profile and Clinical and Virological Outcomes of Nirmatrelvir-Ritonavir Treatment in Patients With Advanced Chronic Kidney Disease and Coronavirus Disease 2019

Post-marketing surveillance study on the effectiveness and safety of molnupiravir in high-risk COVID-19 outpatients: a prospective case series study

BACKGROUND

Molnupiravir, approved for treating mild to moderate COVID-19 in adults, aims to reduce hospitalisation and mortality rates. Although it was withdrawn from the market after the present study was conducted, understanding its long-term effects remains pertinent. We aimed to assess the real-world effectiveness and safety of molnupiravir in high-risk COVID-19 outpatients.

METHODS

This prospective, multicenter, noninterventional, postmarketing cohort study enrolled high-risk COVID-19 outpatients with mild to moderate COVID-19, eligible under national prescribing criteria, who initiated molnupiravir within five days of symptom onset and were ineligible for first-line antiviral therapy. Patients were consecutively enrolled from eight Portuguese study sites and monitored for three months. Effectiveness was assessed by all-cause mortality and hospitalisation through day 29. Safety was evaluated by the incidence, severity, and causality of adverse events (AE), coded using MedDRA terminology and assessed via the WHO-UMC system. Data were collected through structured patient questionnaires and electronic health records. Statistical analysis was descriptive; proportions were reported with 95% confidence intervals (CI), and comparisons between groups were performed using appropriate statistical tests.

RESULTS

By day 29 post-treatment initiation, no deaths were reported (n = 0; 0%; 95%CI = [0,26]), and all patients were either at home or institutionalised, with favourable outcomes. Out of the 12 patients enrolled, eight (67%; 95%CI = [35,90]) reported at least one AE, with the median time to the first AE being five days (range 5-7 days). Half of the patients (n = 6; 95%CI = [21,79]) reported AE deemed possibly or probably related to molnupiravir, involving nausea (25%), dizziness (17%), bitter taste (17%), and headache (17%). These AE were more commonly observed in older individuals and those overweight, indicating a potential influence of these factors on AE occurrence.

CONCLUSIONS

Molnupiravir appears to show good safety and effectiveness, offering an alternative for high-risk COVID-19 outpatients ineligible for first-line therapy. Despite its market withdrawal, ongoing research into its long-term effects is crucial to potentially repurpose it for other viral infections.

Safety and Effectiveness of Nirmatrelvir-Ritonavir in Patients With Advanced Kidney Dysfunction and COVID-19

RATIONALE & OBJECTIVE

Nirmatrelvir-ritonavir prevents COVID-19 hospitalization among high-risk adults, but safety concerns limit its use in advanced kidney dysfunction. This study examined safety and effectiveness outcomes from its off-label use in patients with advanced kidney dysfunction.

STUDY DESIGN

Retrospective matched cohort study.

SETTING & PARTICIPANTS

Patients with estimated glomerular filtration rate (eGFR) 15-30mL/min/1.73m2 and COVID-19 between January 2022 and January 2023 cared for in Veterans Health Administration facilities.

EXPOSURE

Treatment with nirmatrelvir-ritonavir, no treatment with nirmatrelvir-ritonavir or molnupiravir, or treatment with molnupiravir.

OUTCOME

Incidence of cardiac events, stroke, acute kidney injury, liver injury, hypertension, and infection-related death, respiratory failure, pneumonia, severe infection, and hospitalization within 30-60 days of diagnosis with COVID-19.

ANALYTICAL APPROACH

Logistic regression for propensity matching, standardized mean differences for assessment of covariate balance, and conditional logistic regression for estimation of relative risk ratios comparing exposures for each outcome.

RESULTS

Among 4,020 patients with an eGFR of 15-30mL/min/1.73m2 and COVID-19, 117 (2.9%) were treated with nirmatrelvir-ritonavir: mean age, 75.6±12.2 (SD) years and eGFR 24.9±4.0 (SD) mL/min/1.73m2. Compared with no treatment with either nirmatrelvir-ritonavir or molnupiravir, treatment with nirmatrelvir-ritonavir was not detectably associated with different risks of cardiovascular events (eg, heart failure: risk ratio [RR], 1.0 [95% CI, 0.7-1.2]; liver injury: RR, 1.2 [95% CI, 0.7-1.7]; or acute kidney injury: RR, 1.0 [95% CI, 0.8-1.2]), but was associated with a lower risk of acute respiratory failure (RR, 0.5 [95% CI, 0.2-0.7]) and pneumonia (RR, 0.6 [95% CI, 0.3-0.8]). Compared with treatment with molnupiravir, treatment with nirmatrelvir-ritonavir was not detectably associated with different risks of cardiovascular events, acute respiratory failure, or pneumonia but was associated with a higher risk of acute kidney injury. Sensitivity analyses among patients with an eGFR of 15-35mL/min/1.73m2 yielded similar findings.

LIMITATIONS

Retrospective analysis, predominantly men in the study cohort.

CONCLUSIONS

Nirmatrelvir-ritonavir use in the setting of advanced kidney dysfunction was associated with a reduced risk of acute respiratory failure and pneumonia and no detectable differences in non-respiratory adverse outcomes compared with no treatment with either nirmatrelvir-ritonavir or molnupiravir.

PLAIN-LANGUAGE SUMMARY

COVID-19 can cause severe complications in patients with advanced kidney disease, yet nirmatrelvir-ritonavir, one of the first-line antiviral therapies, is not recommended in such patients due to safety concerns. We examined its safety and effectiveness among patients with advanced (stage IV) kidney disease. Using Veterans Health Administration records, we compared patients who received nirmatrelvir-ritonavir with those who were not treated with it nor with molnupiravir (a second-line therapy). We also compared treatment with nirmatrelvir-ritonavir with treatment with molnupiravir. We found that nirmatrelvir-ritonavir was associated with a reduced risk of serious lung problems without any evidence of increased risks of heart, liver, or kidney problems compared with not being treated with nirmatrelvir-ritonavir nor molnupiravir. The effectiveness and safety of nirmatrelvir-ritonavir were similar to that of molnupiravir. This study provides real-world evidence supporting nirmatrelvir-ritonavir use for patients with advanced kidney disease.

Efficacy and safety of antiviral therapies for the treatment of persistent COVID-19 in immunocompromised patients since the Omicron surge: a systematic review

BACKGROUND

Persistent COVID-19 (pCOVID-19) in immunocompromised patients is characterized by unspecific symptoms and pulmonary infiltrates due to ongoing severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) replication. Treatment options remain unclear, leading to different approaches, including combination therapy and extended durations. The purpose of this study was to assess the efficacy and safety of antiviral therapies for pCOVID-19 in immunocompromised patients since the Omicron surge.

METHODS

We searched MEDLINE and Scopus from 1 January 2022 to 6 August 2024 for cohort studies and case series on nirmatrelvir/ritonavir, remdesivir, ensitrelvir and molnupiravir. Evidence certainty was rated using Grading of Recommendations Assessment, Development, and Evaluation for outcomes including viral clearance, recurrence/relapse, mortality, adverse events (AEs) and symptom resolution.

RESULTS

Thirteen studies involving 127 cases were included. Evidence certainty was very low. In combination therapy with at least two direct antiviral agents, viral clearance was 79%, with a 16% recurrence rate. All-cause mortality was 9%, and mortality was 6% while SARS-CoV-2 positive. In 47 cases, AEs were reported in 11%. Symptom resolution ranged from 3 to 6 days in two studies. In combination therapy with one direct antiviral agent and passive immunization, viral clearance was 89%, with an 11% recurrence rate and no deaths. In four documented cases, no AEs were observed. In monotherapy, viral clearance was 100%, with a 15% recurrence rate. One death, unrelated to SARS-CoV-2, occurred. In 12 documented cases, no AEs were observed.

CONCLUSIONS

Based on very low certainty evidence, combining one direct antiviral with passive immunization resulted in high rates of viral clearance and few recurrences. AEs occurred in cases treated with at least two direct antivirals. Controlled studies are needed.

The Effect of Nirmatrelvir-Ritonavir on Short- and Long-term Adverse Outcomes From COVID-19 Among Patients With Kidney Disease: A Propensity Score-Matched Study

Background

Patients with kidney disease are at high risk for adverse outcomes after coronavirus disease 2019 (COVID-19) despite vaccination. Because patients with advanced chronic kidney disease (CKD) and kidney failure were excluded from registrational trials, the impact of the protease inhibitor nirmatrelvir-ritonavir in patients with kidney disease is unknown.

Methods

This was a cohort study evaluating adverse outcomes in patients with kidney disease who developed COVID-19. Patients prescribed nirmatrelvir-ritonavir for COVID-19 between March 16, 2022, and November 30, 2022, were propensity score-matched to comparators diagnosed with COVID-19 between July 15, 2021, and March 15, 2022 (before the use of nirmatrelvir-ritonavir in our health care network). We determined the association between nirmatrelvir-ritonavir and short- and long-term outcomes using Fine-Gray subdistribution hazard and Cox proportional hazard models, adjusting for potential confounders. Outcomes included 30-day risk of hospitalization and 1-year risk of a major adverse cardiovascular event (MACE), CKD progression, and death.

Results

A total of 1095 nirmatrelvir-ritonavir-treated patients were matched to 584 comparators. Patients who received nirmatrelvir-ritonavir patients were less likely to be hospitalized within 30 days of diagnosis (adjusted subdistribution hazard ratio [sHR], 0.44; 95% CI, 0.26-0.73; P < .01). At 1 year, nirmatrelvir-ritonavir-treated patients had a lower risk of hospitalization for MACE (adjusted sHR, 0.49; 95% CI, 0.36-0.67; P < .01) and death (adjusted hazard ratio, 0.37; 95% CI, 0.21-0.65; P < .01). Use of nirmatrelvir-ritonavir was not associated with decreased risk of CKD progression or attenuation of estimated glomerular filtration rate decline slope in the year following infection.

Conclusions

Nirmatrelvir-ritonavir was associated with decreased risk of hospitalization within 30 days and 1-year risk of MACE and death in patients with CKD and kidney failure.

Comparative effectiveness of combination therapy with nirmatrelvir-ritonavir and remdesivir versus monotherapy with remdesivir or nirmatrelvir-ritonavir in patients hospitalised with COVID-19: a target trial emulation study

BACKGROUND

Remdesivir (Veklury, Gilead Sciences, Foster City, CA, USA) and nirmatrelvir-ritonavir (Paxlovid, Pfizer, New York, NY, USA) were reported to improve the outcome of patients with mild-to-moderate COVID-19 symptoms. Preclinical data suggest that nirmatrelvir-ritonavir might be more effective than remdesivir alone or in combination with nirmatrelvir-ritonavir for people at high risk of severe COVID-19. We aimed to assess the safety and effectiveness of combining remdesivir and nirmatrelvir-ritonavir compared with using each drug alone for adults hospitalised with COVID-19.

METHODS

In this target trial emulation study, we used electronic health records of patients aged 18 years or older who received either combination treatment of nirmatrelvir-ritonavir and remdesivir or monotherapy of either drug between March 16 and Dec 31, 2022, within 5 days of hospitalisation for COVID-19 in Hong Kong. Inverse probability of treatment weighting was applied to balance baseline patient characteristics across the treatment groups. The primary outcome was all-cause mortality. Cox proportional hazards regression adjusting weighting was used to compare the risk of all-cause mortality, intensive care unit (ICU) admission, or ventilatory support for 90 days of follow-up between groups.

FINDINGS

Between March 16 and Dec 31, 2022, 18 196 participants were identified from electronic health records and assigned to receive remdesivir (n=4232), nirmatrelvir-ritonavir (n=13 656), or nirmatrelvir-ritonavir and remdesivir (n=308). By applying an inverse probability of treatment weighting, a weighted sample composed of 18 410 recipients of nirmatrelvir-ritonavir and remdesivir combination treatment, 18 178 recipients of remdesivir monotherapy, and 18 287 recipients of nirmatrelvir-ritonavir monotherapy was obtained. After a median follow-up of 84 days (IQR 45-90), risk of mortality was lower in patients who received nirmatrelvir-ritonavir monotherapy (hazard ratio [HR] 0·18 [95% CI 0·15 to 0·20]; absolute risk reduction [ARR] -16·33% [95% CI -16·98 to -15·68]) or remdesivir and nirmatrelvir-ritonavir combination therapy (HR 0·66 [95% CI 0·49 to 0·89]; ARR -6·52% [95% CI -7·29 to -5·74]) than in patients who received remdesivir monotherapy. Similar results were observed for ICU admission or ventilatory support (nirmatrelvir-ritonavir monotherapy: HR 0·09 [95% CI 0·07 to 0·11]; ARR -10·04% [95% CI -10·53 to -9·56]; combination therapy: HR 0·68 [95% CI 0·42 to 1·12]; ARR -3·24% [95% CI -3·84 to -2·64]). Compared with combination therapy, nirmatrelvir-ritonavir monotherapy was associated with lower risk of mortality (HR 0·27 [95% CI 0·20 to 0·37]; ARR -9·81% [95% CI -10·39 to -9·24]) and ICU admission or ventilatory support (HR 0·13 [95% CI 0·08 to 0·22]; ARR -6·80% [95% CI -7·22 to -6·39]).

INTERPRETATION

Our study highlighted the potential for reduced risk of mortality, ICU admission, or the need for ventilatory support in patients hospitalised with COVID-19 treated with nirmatrelvir-ritonavir as a monotherapy compared with treatment regimens based on nirmatrelvir-ritonavir and remdesivir combination therapy or remdesivir monotherapy. Further randomised controlled trials are needed to support the validity of the current results.

FUNDING

The Health and Medical Research Fund Commissioned Research on COVID-19.

TRANSLATION

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

COVID-19 therapeutics

SUMMARYSince the emergence of COVID-19 in 2020, an unprecedented range of therapeutic options has been studied and deployed. Healthcare providers have multiple treatment approaches to choose from, but efficacy of those approaches often remains controversial or compromised by viral evolution. Uncertainties still persist regarding the best therapies for high-risk patients, and the drug pipeline is suffering fatigue and shortage of funding. In this article, we review the antiviral activity, mechanism of action, pharmacokinetics, and safety of COVID-19 antiviral therapies. Additionally, we summarize the evidence from randomized controlled trials on efficacy and safety of the various COVID-19 antivirals and discuss unmet needs which should be addressed.

Comparison of safety and efficacy between Nirmatrelvir-ritonavir and molnupiravir in the treatment of COVID-19 infection in patients with advanced kidney disease: a retrospective observational study

Background

Nirmatrelvir-ritonavir is used in patients with coronavirus disease 2019 (COVID-19) with normal or mild renal impairment (eGFR ≥30 ml/min per 1.73 m2). There is limited data regarding its use in advanced kidney disease (eGFR <30 ml/min per 1.73 m2). We performed a retrospective territory-wide observational study evaluating the safety and efficacy of nirmatrelvir-ritonavir when compared with molnupiravir in the treatment of patients with COVID-19 with advanced kidney disease.

Methods

We adopted target trial emulation using data from a territory-wide electronic health record database on eligible patients aged ≥18 years with advanced kidney disease (history of eGFR <30 ml/min per 1.73 m2) who were infected with COVID-19 and were prescribed with either molnupiravir or nirmatrelvir-ritonavir within five days of infection during the period from 16 March 2022 to 31 December 2022. A sequence trial approach and 1:4 propensity score matching was applied based on the baseline covariates including age, sex, number of COVID-19 vaccine doses received, Charlson comorbidity index (CCI), hospitalisation, eGFR, renal replacement therapy, comorbidities (cancer, respiratory disease, myocardial infarction, ischaemic stroke, diabetes, hypertension), and drug use (renin-angiotensin-system agents, beta blockers, calcium channel blockers, diuretics, nitrates, lipid lowering agents, insulins, oral antidiabetic drugs, antiplatelets, immuno-suppressants, corticosteroids, proton pump inhibitors, histamine H2 receptor antagonists, monoclonal antibody infusion) within past 90 days. Individuals were followed up from the index date until the earliest outcome occurrence, death, 90 days from index date or the end of data availability. Stratified Cox proportional hazards regression adjusted with baseline covariates was used to compare the risk of outcomes between nirmatrelvir-ritonavir recipients and molnupiravir recipients which include (i) all-cause mortality, (ii) intensive care unit (ICU) admission, (iii) ventilatory support, (iv) hospitalisation, (v) hepatic impairment, (vi) ischaemic stroke, and (vii) myocardial infarction. Subgroup analyses included age (<70; ≥70 years); sex, Charlson comorbidity index (≤5; >5), and number of COVID-19 vaccine doses received (0-1; ≥2 doses).

Findings

A total of 4886 patients were included (nirmatrelvir-ritonavir: 1462; molnupiravir: 3424). There were 347 events of all-cause mortality (nirmatrelvir-ritonavir: 74, 5.06%; molnupiravir: 273, 7.97%), 10 events of ICU admission (nirmatrelvir-ritonavir: 4, 0.27%; molnupiravir: 6, 0.18%), 48 events of ventilatory support (nirmatrelvir-ritonavir: 13, 0.89%; molnupiravir: 35, 1.02%), 836 events of hospitalisation (nirmatrelvir-ritonavir: 218, 23.98%; molnupiravir: 618, 28.14%), 1 event of hepatic impairment (nirmatrelvir-ritonavir: 0, 0%; molnupiravir: 1, 0.03%), 8 events of ischaemic stroke (nirmatrelvir-ritonavir: 3, 0.22%; molnupiravir: 5, 0.16%) and 9 events of myocardial infarction (nirmatrelvir-ritonavir: 2, 0.15%; molnupiravir: 7, 0.22%). Nirmatrelvir-ritonavir users had lower rates of all-cause mortality (absolute risk reduction (ARR) at 90 days 2.91%, 95% CI: 1.47-4.36%) and hospitalisation (ARR at 90 days 4.16%, 95% CI: 0.81-7.51%) as compared with molnupiravir users. Similar rates of ICU admission (ARR at 90 days -0.09%, 95% CI: -0.4 to 0.2%), ventilatory support (ARR at 90 days 0.13%, 95% CI: -0.45 to 0.72%), hepatic impairment (ARR at 90 days 0.03%, 95% CI: -0.03 to 0.09%), ischaemic stroke (ARR at 90 days -0.06%, 95% CI: -0.35 to 0.22%), and myocardial infarction (ARR at 90 days 0.07%, 95% CI: -0.19 to 0.33%) were found between nirmatrelvir-ritonavir and molnupiravir users. Consistent results were observed in relative risk adjusted with baseline characteristics. Nirmatrelvir-ritonavir was associated with significantly reduced risk of all-cause mortality (HR: 0.624, 95% CI: 0.455-0.857) and hospitalisation (HR: 0.782, 95% CI: 0.64-0.954).

Interpretation

Patients with COVID-19 with advanced kidney disease receiving nirmatrelvir-ritonavir had a lower rate of all-cause mortality and hospital admission when compared with molnupiravir. Other adverse clinical outcomes were similar in both treatment groups.

Funding

Health and Medical Research Fund (COVID1903010), Health Bureau, The Government of the Hong Kong Special Administrative Region, China.

Effectiveness and safety of nirmatrelvir-ritonavir in kidney transplant recipients with severe kidney dysfunction infected with COVID-19

Transplant patients face an elevated risk of coronavirus disease 2019 (COVID-19) morbidity and mortality and commonly encounter renal dysfunction. Nirmatrelvir is primarily excreted through the kidneys. The dosage of nirmatrelvir/ritonavir (NR) needs to be adjusted according to the degree of renal function impairment. Nevertheless, NR is not recommended for patients with severe renal impairment (estimated glomerular filtration rate < 30 mL/min) due to a dearth of associated research. In this study, we focus on kidney transplant patients and document and analyze the experiences of using NR in individuals with severe kidney dysfunction. This was a retrospective multicenter study that included transplant recipients hospitalized for COVID-19 in five major tertiary hospitals in China from December 2022 to June 2023. The outcomes consisted of the disease progression rate by day 28, individual disease progression events, safety outcomes, information on adverse events (AEs), and the blood drug concentrations of immunosuppressants. Data were presented with descriptive statistics. All analyses were performed using SPSS version 22. In total, 40 patients were included in the analysis. Considering the potential interaction between drugs, all patients temporarily discontinued their immunosuppressants during the NR treatment. None of the 32 moderate patients experienced disease progression. However, among the eight patients with critical COVID-19, unfortunately, two of them died. During the medication period, four patients experienced a total of six AEs associated with NR. None of them experienced AEs with a maximum grade of ≥3. Blood drug concentrations of immunosuppressants were monitored in 22 of 40 patients, and the blood drug concentrations of immunosuppressants did not show a significant increase, but some patients experienced lower blood drug concentrations. Our findings supported the use of NR therapy for the treatment of COVID-19 in transplant patients with severe renal insufficiency. A modified dose of NR was well-tolerated.

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.