A network meta-analysis of the efficacy and safety of baloxavir marboxil versus neuraminidase inhibitors for the treatment of influenza in otherwise healthy patients

Rapid health technology assessment of the novel endonuclease inhibitor baloxavir for the treatment of influenza

Through a Rapid Health Technology Assessment (RHTA), we evaluated the efficacy, safety and cost-effectiveness of baloxavir in the treatment of influenza, providing the necessary scientific information and evidence-based basis for healthcare professionals and health insurance decision-makers in making rational selections. Through systematic searches of Pubmed, Embase, Web of Science, The Cochrane Register of Clinical Trials database and the official website of Health Technology Assessment (HTA) agencies, we collected systematic reviews (SR)/Meta-analysis, cost-effectiveness evaluations and HTA reports of baloxavir for influenza, with a search time frame of date of database establishment to July 31, 2022. We then performed data extraction, literature screening and quality evaluation on the literature that met our selection criteria, after which the results of the studies were pooled and qualitatively described for analysis. 10 studies were included, including 6 SR/Meta-analysis, three economics studies, and 1 HTA report. In terms of efficacy, baloxavir had an advantage over oseltamivir for all three types of influenza patients (otherwise healthy patients, high-risk patients, and patients are not separated into groups with and without underlying health conditions) concerning change in virus titer from baseline at 24 and 48 h; about otherwise healthy patients and high-risk patients, baloxavir had an advantage over peramivir; pertaining to high-risk patients, baloxavir had an advantage over laninamivir; the above differences between groups were all statistically significant. In terms of safety, in otherwise healthy patients and patients are not separated into groups with and without underlying health conditions, baloxavir significantly reduced the incidence of DRAEs and nausea compared with oseltamivir, as well as significantly reduced the incidence of DRAEs compared with laninamivir; in patients are not separated into groups with and without underlying health conditions, baloxavir significantly reduced the incidence of AEs and diarrhoea compared with oseltamivir; the differences between the above groups were all statistically significant. Economically, in Japanese adult influenza patients and high-risk populations, the Quality-Adjusted Life Years (QALY) of baloxavir slightly triumphed over that of laninamivir (Δ = 0.000112 and 0.00209 QALY per 1 patient, respectively); moreover, the incremental cost-effectiveness ratio (ICER: 2,231,260 and 68,855 yen/QALY, respectively) was below the willingness-to-pay (WTP) threshold (5,000,000 yen/QALY); in Chinese adult influenza patients without underlying diseases and adult high-risk influenza patients, baloxavir had a higher QALY compared with oseltamivir (Δ = 0.000246 and 0.000186 respectively), however, their ICER (12,230 and 64,956 RMB/QALY) was above the local WTP threshold (10,000 RMB/QALY) and thus did not provide a cost-effectiveness advantage. Baloxavir had a favorable efficacy and safety profile compared to neuraminidase inhibitors (NAIs), and the currently available evidence suggested that it had an economic advantage only in Japan.

Safety analysis of Oseltamivir and Baloxavir Marboxil after market approval: a pharmacovigilance study based on the FDA adverse event reporting system

BACKGROUND AND OBJECTIVES

Amidst limited influenza treatment options, evaluating the safety of Oseltamivir and Baloxavir Marboxil is crucial, particularly given their comparable efficacy. This study investigates post-market safety profiles, exploring adverse events (AEs) and their drug associations to provide essential clinical references.

METHODS

A meticulous analysis of FDA Adverse Event Reporting System (FAERS) data spanning the first quarter of 2004 to the fourth quarter of 2022 was conducted. Using data mining techniques like reporting odds ratio (ROR), proportional reporting ratio, Bayesian Confidence Propagation Neural Network, and Multiple Gamma Poisson Shrinkage, AEs related to Oseltamivir and Baloxavir Marboxil were examined. Venn analysis compared and selected specific AEs associated with each drug.

RESULTS

Incorporating 15,104 Oseltamivir cases and 1,594 Baloxavir Marboxil cases, Wain analysis unveiled 21 common AEs across neurological, psychiatric, gastrointestinal, dermatological, respiratory, and infectious domains. Oseltamivir exhibited 221 significantly specific AEs, including appendicolith [ROR (95% CI), 459.53 (340.88 ∼ 619.47)], acne infantile [ROR (95% CI, 368.65 (118.89 ∼ 1143.09)], acute macular neuroretinopathy [ROR (95% CI), 294.92 (97.88 ∼ 888.64)], proctitis [ROR (95% CI), 245.74 (101.47 ∼ 595.31)], and Purpura senile [ROR (95% CI), 154.02 (81.96 ∼ 289.43)]. designated adverse events (DMEs) associated with Oseltamivir included fulminant hepatitis [ROR (95% CI), 12.12 (8.30-17.72), n=27], ventricular fibrillation [ROR (95% CI), 7.68 (6.01-9.83), n=64], toxic epidermal necrolysis [ROR (95% CI), 7.21 (5.74-9.05), n=75]. Baloxavir Marboxil exhibited 34 specific AEs, including Melaena [ROR (95% CI), 21.34 (14.15-32.18), n = 23], cystitis haemorrhagic [ROR (95% CI), 20.22 (7.57-54.00), n = 4], ileus paralytic [ROR (95% CI), 18.57 (5.98-57.71), n = 3], and haemorrhagic diathesis [ROR (95% CI), 16.86 (5.43-52.40)), n = 3]. DMEs associated with Baloxavir Marboxil included rhabdomyolysis [ROR (95% CI), 15.50 (10.53 ∼ 22.80), n = 26].

CONCLUSION

Monitoring fulminant hepatitis during Oseltamivir treatment, especially in patients with liver-related diseases, is crucial. Oseltamivir's potential to induce abnormal behavior, especially in adolescents, necessitates special attention. Baloxavir Marboxil, with lower hepatic toxicity, emerges as a potential alternative for patients with liver diseases. During Baloxavir Marboxil treatment, focused attention on the occurrence of rhabdomyolysis is advised, necessitating timely monitoring of relevant indicators for those with clinical manifestations. The comprehensive data aims to provide valuable insights for clinicians and healthcare practitioners, facilitating an understanding of the safety profiles of these influenza treatments in real-world scenarios.

Comparative Effectiveness of Baloxavir Marboxil and Oseltamivir Treatment in Reducing Household Transmission of Influenza: A Post Hoc Analysis of the BLOCKSTONE Trial

BACKGROUND

The transmission of influenza virus in households, especially by children, is a major route of infection. Prior studies suggest that timely antiviral treatment of ill cases may reduce infection in household contacts. The aim of the study was to compare the effects of oseltamivir (OTV) and baloxavir marboxil (BXM) treatment of index cases on the secondary attack rate (SAR) of influenza within household.

METHODS

A post hoc analysis was done in BLOCKSTONE trial-a placebo-controlled, double-blinded post-exposure prophylaxis of BXM. Data were derived from the laboratory-confirmed index cases' household contacts who received placebo in the trial and also from household members who did not participate in the trial but completed illness questionnaires. To assess the SAR of household members, multivariate analyses adjusted for factors including age, vaccination status, and household size were performed and compared between contacts of index cases treated with BXM or OTV.

RESULTS

In total, 185 index cases (116 treated with BXM and 69 treated with OTV) and 410 household contacts (201 from trial, 209 by questionnaire) were included. The Poisson regression modeling showed that the SAR in household contacts of index cases treated with BXM and OTV was 10.8% and 18.5%, respectively; the adjusted relative reduction in SAR was 41.8% (95% confidence interval: 1.0%-65.7%, p = 0.0456) greater with BXM than OTV. Similar reductions were found in contacts from the trial and those included by questionnaire.

CONCLUSION

BXM treatment of index cases appeared to result in a greater reduction in secondary household transmission than OTV treatment.

[Application of HS221GI in treatment of influenza and ARVI in adults: a new approach - managing virus-induced inflammation. Results of a double-blind, randomized, placebo-controlled, multicenter clinical trial]

AIM

Evaluation of the efficacy and safety of the drug Aterixen® (XC221GI, 1-[2-(1-methylimidazole-4-yl)-ethyl]perhydroazine-2,6-dione), in the treatment of uncomplicated forms of influenza and other ARVI in adults.

MATERIALS AND METHODS

The phase III clinical trial enrolled 260 people aged 18-65 years with mild and moderate forms of influenza or other ARVI. Patients were randomly assigned to two groups: in group 1 (n=130), patients were prescribed the drug Aterixen® in tablets of 100 mg 2 times a day for 5 days; in group 2 (n=130) - a placebo corresponding to the drug, in the same regimen. The primary endpoint of the efficacy assessment was the time in hours from the first administration of the drug to clinical improvement. The main efficacy analysis was performed in a population of patients with PCR-confirmed influenza or ARVI who completed the study according to the protocol (per protocol infected). Additionally, efficacy was evaluated in ITT and PP populations, including patients with both identified and undetected pathogen. The population for safety analysis included all patients, without exception, who were exposed to at least one exposure to the study drug or placebo.

RESULTS

A statistically significant superiority of the drug Aterixen® over placebo in primary endpoint was revealed in both the main and additional analysis in all studied populations: clinical improvement in the group of the studied drug occurred 24 hours faster compared with the placebo group. The evaluation of the effectiveness of secondary endpoints confirmed the superiority of the drug Aterixen® over placebo in terms of relief of catarrhal symptoms and symptoms of intoxication. A favorable safety profile of the drug has been demonstrated.

CONCLUSION

The drug has demonstrated a favorable safety profile for use in outpatient practice. Aterixen® is an effective and safe treatment for influenza and other ARVI in adults.

Factors associated with viral RNA shedding and evaluation of potential viral infectivity at returning to school in influenza outpatients after treatment with baloxavir marboxil and neuraminidase inhibitors during 2013/2014-2019/2020 seasons in Japan: an observational study

BACKGROUND

This study assessed the differences in daily virus reduction and the residual infectivity after the recommended home stay period in Japan in patients infected with influenza and treated with baloxavir (BA), laninamivir (LA), oseltamivir (OS), and zanamivir (ZA).

METHODS

We conducted an observational study on children and adults at 13 outpatient clinics in 11 prefectures in Japan during seven influenza seasons from 2013/2014 to 2019/2020. Virus samples were collected twice from influenza rapid test-positive patients at the first and second visit 4-5 days after the start of treatment. The viral RNA shedding was quantified using quantitative RT-PCR. Neuraminidase (NA) and polymerase acidic (PA) variant viruses that reduce susceptibility to NA inhibitors and BA, respectively, were screened using RT-PCR and genetic sequencing. Daily estimated viral reduction was evaluated using univariate and multivariate analyses for the factors such as age, treatment, vaccination status, or the emergence of PA or NA variants. The potential infectivity of the viral RNA shedding at the second visit samples was determined using the Receiver Operator Curve based on the positivity of virus isolation.

RESULTS

Among 518 patients, 465 (80.0%) and 116 (20.0%) were infected with influenza A (189 with BA, 58 with LA, 181 with OS, 37 with ZA) and influenza B (39 with BA, 10 with LA, 52 with OS, 15 with ZA). The emergence of 21 PA variants in influenza A was detected after BA treatment, but NA variants were not detected after NAIs treatment. Multiple linear regression analysis showed that the daily viral RNA shedding reduction in patients was slower in the two NAIs (OS and LA) than in BA, influenza B infection, aged 0-5 years, or the emergence of PA variants. The residual viral RNA shedding potentially infectious was detected in approximately 10-30% of the patients aged 6-18 years after five days of onset.

CONCLUSIONS

Viral clearance differed by age, type of influenza, choice of treatment, and susceptibility to BA. Additionally, the recommended homestay period in Japan seemed insufficient, but reduced viral spread to some extent since most school-age patients became non-infectious after 5 days of onset.

Preparing for the Next Influenza Season: Monitoring the Emergence and Spread of Antiviral Resistance

Purpose

The relaxation of pandemic restrictions in 2022 has led to a reemergence of respiratory virus circulation worldwide and anticipation of substantial influenza waves for the 2022/2023 Northern Hemisphere winter. Therefore, the antiviral susceptibility profiles of human influenza viruses circulating in Germany were characterized.

Methods

Between October 2019 (week 40/2019) and March 2022 (week 12/2022), nasal swabs from untreated patients with acute respiratory symptoms were collected in the national German influenza surveillance system. A total of 598 influenza viruses were isolated and analyzed for susceptibility to oseltamivir, zanamivir and peramivir, using a neuraminidase (NA) inhibition assay. In addition, next-generation sequencing was applied to assess molecular markers of resistance to NA, cap-dependent endonuclease (PA) and M2 ion channel inhibitors (NAI, PAI, M2I) in 367 primary clinical samples. Furthermore, a genotyping assay based on RT-PCR and pyrosequencing to rapidly assess the molecular resistance marker PA-I38X in PA genes was designed and established.

Results

While NAI resistance in the strict sense, defined by a ≥ 10-fold (influenza A) or ≥5-fold (influenza B) increase of NAI IC₅₀, was not detected, a subtype A(H1N1)pdm09 isolate displayed 2.3- to 7.5-fold IC₅₀ increase for all three NAI. This isolate carried the NA-S247N substitution, which is known to enhance NAI resistance induced by NA-H275Y. All sequenced influenza A viruses carried the M2-S31N substitution, which confers resistance to M2I. Of note, one A(H3N2) virus displayed the PA-I38M substitution, which is associated with reduced susceptibility to the PAI baloxavir marboxil. Pyrosequencing analysis confirmed these findings in the original clinical specimen and in cultured virus isolate, suggesting sufficient replicative fitness of this virus mutant.

Conclusion

Over the last three influenza seasons, the vast majority of influenza viruses in this national-level sentinel were susceptible to NAIs and PAIs. These findings support the use of antivirals in the upcoming influenza season.

An overview of the characteristics and methodological standards across systematic reviews with Meta-analysis of efficacy/effectiveness of influenza antiviral drugs

BACKGROUND

Influenza antiviral drugs remain controversial and it is not clear if conclusions on their efficacy/effectiveness are based on high quality systematic reviews (SRs). We systematically identified, critically appraised, and summarized the characteristics and adherence to methodological standards in SRs with meta-analysis of efficacy/effectiveness of influenza antiviral drugs for prevention and/or treatment of influenza.

METHODS

We searched MEDLINE, Embase, Scopus, CINAHL, Global Health, and CDSR for English-language SR publications up to July 2020. We summarized the characteristics, adherence to methodological standards and SR quality (AMSTAR 2).

RESULTS

From a total 3,898 citations after removal of duplicates from all identified citations, we included 24 SRs. Seventy-five percent (n = 18) were of a critically low quality, 8% (n = 2) of a low quality, 17% (n = 4) of a moderate quality, and none were of a high quality. Seventeen percent (n = 4) were industry-funded, 4% (n = 1) coauthored by industry employee(s), and 33% (n = 8) commissioned by an organization or authority. Only 33% percent (n = 8) reported protocol registration, 4% (n = 1) reported collaboration with a knowledge synthesis librarian/information specialist, and 17% (n = 4) utilized a systematic review reporting checklist.

CONCLUSIONS

The evidence suggests that SRs of efficacy/effectiveness of influenza antiviral drugs are mostly of critically low quality and do not follow current best SR practices. These findings are significant in view of the important role of SRs in decision-making and the controversies that surround the use of the influenza antiviral drugs. However, the findings should not be interpreted to mean curtailment/cessation of use of antiviral drugs for influenza.

Efficacy and safety of single-dose antiviral drugs for influenza treatment: A systematic review and network meta-analysis

To conduct network meta-analysis (NMA) of clinical efficacy and safety of single-dose antiviral drugs, grouped by dosage, in treatment of influenza. Systematic retrievals were conducted in databases, including Pubmed, Embase, Web of Science, the Cochrane Register of Clinical Trials and from the website ClinicalTrials.gov, for clinical trials recorded between the interception of the databases and March 31, 2021. Randomized controlled trials (RCTs) of influenza treatment in which single-dose antiviral drugs were administered were selected according to preset inclusion and exclusion criteria by two researchers who screened the literature independently from each other. The quality of the included studies was assessed using the Cochrane bias risk assessment tool. Software such as Stata 16.0 and Review Manager 5.3 was adopted for statistical analysis. Pairwise meta-analysis and NMA were carried out under the random-effects model. For both binary and continuous variables, odds ratio (OR), mean difference (MD) and their 95% confidence intervals (CI) were used to rank treatment efficiencies and analyze the differences. A total of 12 RCTs involving 7296 participants were included in the analysis. According to the NMA results, peramivir 300 mg (MD = -17.68, 95% CI: [-34.05, -1.32]), peramivir 600 mg (MD = -16.15, 95% CI: [-29.35, -2.95]), baloxavir (MD = -14.67, 95% CI: [-26.75, -2.58]) and laninamivir 40 mg (MD = -12.42, 95% CI: [-22.53, -2.31]) remarkably outperformed laninamivir 20 mg in time to alleviation of symptoms (TTAS). However, no intervention statistically outperform others in antipyretic time, virus titer variations against the baseline 24 and 48 h after medication and adverse events (AEs). The efficacy rankings were: peramivir 300 mg (the surface under the cumulative ranking curve [SUCRA] = 80.3%) > peramivir 600 mg (SUCRA = 76.2%) > baloxavir (SUCRA = 68.4%) > laninamivir 40 mg (SUCRA = 55.0%) > laninamivir 20 mg (SUCRA = 16.6%) for TTAS; baloxavir (SUCRA = 76.3%) > peramivir 600 mg (SUCRA = 67.8%) > laninamivir 40 mg (SUCRA = 47.2%) > laninamivir 20 mg (SUCRA = 40.0%) for antipyretic time; baloxavir (SUCRA = 96.7%) > peramivir 300 mg (SUCRA = 64.5%) ≈ peramivir 600 mg (SUCRA = 63.2%), baloxavir (SUCRA = 93.2%) > peramivir 600 mg (SUCRA = 64.0%) ≈ peramivir 300 mg (SUCRA = 55.0%), for virus titer variations against the baseline 24 and 48 h after medication, respectively; and baloxavir (SUCRA = 83.4%) > peramivir 300 mg (SUCRA = 71.4%) > laninamivir 20 mg (SUCRA = 62.4%) > peramivir 600 mg (SUCRA = 56.2%) > laninamivir 40 mg (SUCRA = 36.8%) for adverse events. Among the single-dose anti-influenza virus drugs compared, peramivir is superior to baloxavir and laninamivir in TTAS, whereas baloxavir has the best efficacy in antipyretic time, virus titer variations against the baseline 24 and 48 h after medication and AEs. This study has been registered in the International Prospective Register of Systematic Reviews (PROSPERO), with a registration number of CRD42021238220.

Comparison of intra-familial transmission of influenza virus from index patients treated with baloxavir marboxil or oseltamivir using an influenza transmission model and a health insurance claims database

Background

Influenza affects approximately a billion people globally, including > 10 million Japanese individuals every year. Baloxavir marboxil (baloxavir [BXM]; a selective cap-dependent endonuclease inhibitor) is approved for influenza treatment in Japan. We compared the incidence of intra-familial transmission of influenza between BXM and oseltamivir (OTV) treatments using a simulation model.

Methods

Using the JMDC Claims Database, we identified index case (IC) as the first family member diagnosed with influenza during the 2018–19 influenza season, and classified the families into BXM or OTV group per the drug dispensed to ICs. Using a novel influenza intra-familial infection model, we simulated the duration of influenza infection in ICs based on agent-specific virus shedding periods. Intra-familial infections were defined as non-IC family members infected during the agent-specific viral shedding period in ICs. The virus incubation periods in the non-IC family members were considered to exclude secondary infections from potentially external exposure. The primary endpoint was proportion of families with intra-familial infections. For between-group comparisons, we used a multivariate logistic regression model.

Results

The median proportion of families with intra-familial transmission was 9.57% and 19.35% in the BXM (N = 84 672) and OTV (N = 62 004) groups, respectively. The multivariate odds ratio of 1.73 (2.5th–97.5th percentiles, 1.68–1.77) indicated a substantially higher incidence of intra-familial infections in the OTV group versus the BXM group. Subgroup analyses by ICs’ age category, virus type, and month of onset revealed similar trends favoring BXM.

Conclusions

BXM treatment of ICs may contribute to a greater reduction in intra-familial influenza transmission than OTV treatment.

[Antiviral drugs : Potent agents, promising therapies for COVID‑19 and therapeutic limitations]

Antiviral drugs inhibit viral replication by interaction with specific elements of the viral replication cycle. Directly acting antiviral agents have revolutionized the therapeutic options for chronic infections with human immunodeficiency virus (HIV), hepatitis B virus (HBV) and hepatitis C virus (HCV). Pharmacological developments constantly improve therapeutic and prophylactic options for diseases caused by herpes viruses, which is of particular relevance for immunocompromised patients. While infections with persistent viruses, such as HIV, HBV or herpes viruses principally so far cannot be cured, complete elimination of viruses that cause acute infections is possible; however, acute infections, such as influenza or coronavirus disease 2019 (COVID-19) offer only a small therapeutic window for antiviral strategies due to their pathophysiological dynamics. The optimal time point for antiviral agents is immediately after exposure to the virus, which frequently limits its application in practice. An effective pre-exposure or postexposure prophylaxis has been established for infections with HIV and influenza A/B and also gains relevance for infections with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

Antiviral Treatments for Influenza

Influenza is an acute respiratory illness caused by the influenza A, B, and C viruses. It can occur in local outbreaks or seasonal epidemics, with possibility to spread worldwide in a pandemic when a novel strain with significant antigenic differences emerges. During the past years, several new drugs have become available, with different accessibility related to specific countries' approval. We have conducted a review of literature, analyzing the most recent data on efficacy and safety of drugs currently available to treat influenza, with a particular attention toward special populations. Efficacy and safety profile of neuraminidase inhibitors (oseltamivir, zanamivir, laninamivir, peramivir) and recently approved cap-dependent endonuclease inhibitor baloxavir marboxil are reported in literature, but still little information is available about special populations such as critically ill patients and patients with a history of chronic respiratory disease. Moreover, the emergence of strains with reduced or no susceptibility to current drugs is a matter of concern, suggesting the need of constant monitoring of viral variants.

Coumarin Derivative N6 as a Novel anti-hantavirus Infection Agent Targeting AKT

Hantaviruses are globally emerging zoonotic viruses that can cause hemorrhagic fever with renal syndrome (HFRS) in Asia and Europe, which is primarily caused by Hantaan virus (HTNV) infection, results in profound morbidity and mortality. However, no specific treatment is available for this disease. Coumarin derivatives have been reported as antiviral molecules, while studies about the bioactivity of coumarin derivatives against HTNV infection are limited. To study the potential antiviral activity of coumarin derivatives, 126 coumarin derivatives are synthesized, and their inhibitory activity against HTNV is analyzed in vitro. Among these compounds, N6 inhibits HTNV with relatively high selectivity index at 10.9, and the viral titer of HTNV is reduced significantly after 5, 10, and 20 μM N6 treatments. Furthermore, the administration of N6 at the early stage of HTNV infection can inhibit the replication and production of infectious HTNV in host cell, this therapeutic efficacy is confirmed in HTNV-infected newborn mice at the early stage of infection. The molecular docking results show that N6 forms interactions with the key amino acid residues at its active site, and reveals several molecular interactions responsible for the observed affinity, and the treatment of N6 can inhibit the expression of p (Ser473)Akt and HTNV nucleocapsid protein significantly. As such, these observations demonstrate that coumarin derivative N6 might be used as a potential agent against HTNV infection.

Comparative effectiveness of neuraminidase inhibitors in patients with influenza: A systematic review and network meta-analysis

The aim of this study was to use a network meta-analysis (NWA) to evaluate the relative efficacy and safety of various neuraminidase inhibitors (NAIs) in reducing the duration of influenza symptoms, and thereby, informing the selection of suitable therapeutic regimens for patients with influenza. We conducted a systematic review of randomized controlled trials comparing the clinical effects of four NAIs administered to patients with influenza and placebo. Relevant studies were found in the PubMed and Cochrane databases. Unpublished studies were collected from the ClinicalTrials.gov registry and through hand searching. We carried out NWA to compare the different regimens with each other and across subgroups of age and medical status (high-risk patients). A total of 58 two-arm studies were identified. Five regimens were efficacious in reducing the time to alleviation of influenza symptoms in all populations; this efficacy was comparable. No significant improvements were seen in combination therapy groups. The mean difference in the time to alleviation of symptoms ranged from 12.78 to 19.51 h. According to the summarized mean difference and surface under the cumulative ranking curve (SUCRA), peramivir (SUCRA = 82.6%), zanamivir (SUCRA = 64%), and oseltamivir (SUCRA = 55.1%) were the three top-ranking drugs for treating influenza. Zanamivir and peramivir were the preferred pharmacologic intervention among all investigated interventions based on the calculated "value preference of SUCRA." This study is a network meta-analysis to explore the therapeutic effects of NAIs in patients with influenza. Peramivir might be the best choice for reducing the time to alleviation of symptoms.

Comparison of Antiviral Agents for Seasonal Influenza Outcomes in Healthy Adults and Children: A Systematic Review and Network Meta-analysis

IMPORTANCE

Antiviral treatment of influenza is recommended for patients with influenza-like illness during periods of community cocirculation of influenza viruses and SARS-CoV-2; however, questions remain about which treatment is associated with the best outcomes and fewest adverse events.

OBJECTIVE

To compare the efficacy and safety of neuraminidase inhibitors and the endonuclease inhibitor for the treatment of seasonal influenza among healthy adults and children.

DATA SOURCES

Medline, Embase, and the Cochrane Register of Clinical Trials were searched from inception to January 2020 (the last search was updated in October 2020).

STUDY SELECTION

Included studies were randomized clinical trials conducted among patients of all ages with influenza treated with neuraminidase inhibitors (ie, oseltamivir, peramivir, zanamivir, or laninamivir) or an endonuclease inhibitor (ie, baloxavir) compared with other active agents or placebo.

DATA EXTRACTION AND SYNTHESIS

Two investigators identified studies and independently abstracted data. Frequentist network meta-analyses were performed; relative ranking of agents was conducted using P-score probabilities. Quality of evidence was assessed using the Grading of Recommendations, Assessment, Development and Evaluations criteria. Data were analyzed in October 2020.

MAIN OUTCOMES AND MEASURES

The time to alleviation of influenza symptoms (TTAS), complications of influenza, and adverse events (total adverse events, nausea, and vomiting).

RESULTS

A total of 26 trials were identified that investigated antiviral drugs at high or low doses; these trials included 11 897 participants, among whom 6294 (52.9%) were men and the mean (SD) age was 32.5 (16.9) years. Of all treatments comparing with placebo in efficacy outcomes, high-quality evidence indicated that zanamivir was associated with the shortest TTAS (hazard ratio, 0.67; 95% CI, 0.58-0.77), while baloxavir was associated with the lowest risk of influenza-related complications (risk ratio [RR], 0.51; 95% CI, 0.32-0.80) based on moderate-quality evidence. In safety outcomes, baloxavir was associated with the lowest risk of total adverse events (RR, 0.84; 95% CI, 0.74-0.96) compared with placebo based on moderate-quality evidence. There was no strong evidence of associations with risk of nausea or vomiting among all comparisons, except for 75 mg oseltamivir, which was associated with greater occurrence of nausea (RR, 1.82; 95% CI, 1.38-2.41) and vomiting (RR, 1.88; 95% CI, 1.47-2.41).

CONCLUSIONS AND RELEVANCE

In this systematic review and network meta-analysis, all 4 antiviral agents assessed were associated with shortening TTAS; zanamivir was associated with the shortest TTAS, and baloxavir was associated with reduced rate of influenza-related complications.

Baloxavir Marboxil: A Review in Acute Uncomplicated Influenza

Baloxavir marboxil (Xofluza^®; hereafter referred to as baloxavir), the prodrug of baloxavir acid, is a first-in-class, small molecule inhibitor of the polymerase acidic (PA) protein subunit of the influenza virus polymerase complex. Baloxavir (after conversion to baloxavir acid) acts to block influenza virus replication by inhibiting the cap-dependent endonuclease activity of the PA protein. Taken orally as a single dose, baloxavir is approved in the USA for the treatment of acute uncomplicated influenza in patients ≥ 12 years of age who have been symptomatic for ≤ 48 h. Data from randomized, double-blind, placebo- and oseltamivir-controlled phase III trials have shown that baloxavir is efficacious in improving influenza symptoms both in otherwise healthy adolescents and adults and in those at high risk of influenza complications, displaying similar efficacy to that of oseltamivir. Furthermore, there is evidence that baloxavir can reduce influenza viral load more rapidly than oseltamivir. Baloxavir has activity against influenza A and B viruses (including strains resistant to neuraminidase inhibitors) and is well tolerated. Evidence of the emergence and likely human-to-human transmission of variant viruses with reduced susceptibility to baloxavir highlights the importance of monitoring and surveillance for changes in influenza virus drug susceptibility patterns. However, currently available evidence suggests that baloxavir, with the benefits of a single oral dose regimen, provides a useful alternative to neuraminidase inhibitors for the treatment of acute uncomplicated influenza in adolescents and adults.

Prophylaxis and treatment of influenza: options, antiviral susceptibility, and existing recommendations

Influenza viruses of types A and B attack 5-10% of adults and 20-30% of children, thereby causing millions of acute respiratory infections in Germany annually. A significant number of these infections are associated with complications such as pneumonia and bacterial superinfections that need hospitalization and might lead to death. In addition to vaccines, drugs were developed that might support influenza prevention and that can be used to treat influenza patients. The timely application of anti-influenza drugs can inhibit virus replication, help reduce and shorten the symptoms, and prevent death as well as virus transmission. This review concisely describes the mechanism of action, the potential for prophylactic and therapeutic use, and the knowledge on resistance of anti-influenza drugs approved today. However, the main aim is to give an overview on the recommendations available in Germany for the proper use of these drugs. In doing so, the recommendations published in statements and guidelines of medical societies as well as the German influenza pandemic preparedness plan are summarized with the consideration of specific circumstances and groups of patients.

Clinical efficacy and safety of baloxavir marboxil in the treatment of influenza: A systematic review and meta-analysis of randomized controlled trials

PURPOSE

The aim of this meta-analysis is to compare the clinical efficacy and safety of baloxavir with other anti-influenza agents or placebo in the treatment of influenza.

METHODS

PubMed, Embase, Web of Science, Google Scholar, Scopus, CINAHL, Cochrane databases and clinical registration were searched from inception until February 15 2021 for relevant randomized controlled trials (RCTs). Only phase 3 RCTs evaluating the usefulness of baloxavir in the treatment of influenza were included.

RESULTS

Three RCTs enrolling 3771 patients (baloxavir group, n = 1451; oseltamivir group, n = 1288; placebo group, n = 1032) were included. Compared with oseltamivir, baloxavir had an insignificantly shorter time to the alleviation of symptoms (mean difference [MD], -1.29 h; 95% CI, -6.80 to 4.21; I² = 0%). In contrast, baloxavir had a significantly shorter time to the alleviation of symptoms than placebo (MD, -26.32 h; 95% CI, -33.78 to -18.86; I² = 0%). Baloxavir was associated with a significant decline in influenza virus titers and viral RNA load compared to oseltamivir and placebo. Baloxavir was associated with a lower risk of any adverse events than oseltamivir (OR, 0.82; 95% CI, 0.69-0.98; I² = 0%) and placebo (OR, 0.79; 95% CI, 0.66-0.96; I² = 0%).

CONCLUSIONS

The findings of this meta-analysis suggested that baloxavir is superior to placebo in the treatment of influenza in both clinical outcome and virological response. Moreover, baloxavir was found to have a better virological response than oseltamivir and to be as effective as oseltamivir clinically. Compared with oseltamivir and placebo, baloxavir appears to be a relatively safe anti-influenza agent.

Neuraminidase inhibitors and single dose baloxavir are effective and safe in uncomplicated influenza: a meta-analysis of randomized controlled trials

BACKGROUND

Scarce evidence verifying the clinical impact of baloxavir on influenza complications is found.

METHODS

PubMed, Cochrane Library, and Web of Science databases were searched through December 2020. Randomized-controlled trials (RCT) that enrolled patients with laboratory-confirmed influenza receiving neuraminidase inhibitors (NAI) or baloxavir comparing to placebo were assessed. PROSPERO Registration-number: CRD42021226854.

RESULTS

Twenty-one RCTs (11,697 patients) were included. Antiviral administration significantly reduced time to clinical resolution (mean difference: -21.3 hours) and total influenza-related complications (OR:0.55, 95%CI: 0.42-0.73). Specifically, antivirals significantly decreased bronchitis (OR:0.54, 95%CI: 0.38-0.75), sinusitis (OR:0.51, 95%CI: 0.33-0.78), acute otitis media (OR:0.48, 95%CI: 0.30-0.77), and antibiotic prescription (OR:0.62; 95%CI: 0.48-0.80). A positive trend favored antivirals administration to reduce pneumonia (OR:0.47, 95%CI: 0.16-1.33), or hospitalization rates (OR:0.65; 95%CI: 0.34-1.24) compared to placebo, but did not reach statistical significance. Adverse events (AE) were reported in 11%, 8.9%, and 5.1% of NAIs, placebo and baloxavir recipients, respectively. Compared with NAIs, administration of baloxavir showed non-significantly reduced AEs (OR:0.74, 95%CI: 0.53-1.04).

CONCLUSIONS

Single-dose baloxavir and NAIs were superior to placebo to reduce complications in uncomplicated influenza, with 40% significant reduction in antibiotic prescription. Safety and efficacy of single-dose baloxavir were non-inferior to NAIs.

Efficacy and safety of baloxavir marboxil versus neuraminidase inhibitors in the treatment of influenza virus infection in high-risk and uncomplicated patients - a Bayesian network meta-analysis

OBJECTIVES

Previous network meta-analysis (NMA) demonstrated advantageous or similar efficacy of baloxavir marboxil (baloxavir) over neuraminidase inhibitors in otherwise healthy (OwH) influenza patients. This analysis assessed the efficacy and safety of baloxavir in the subgroup of high-risk (HR) patients and in the population of uncomplicated influenza consisting of OwH and HR patients with influenza.

METHODS

A systematic literature review (SLR) was performed in Medline, Embase, CENTRAL and ICHUSHI up to August 8th, 2018. A Bayesian NMA was conducted to compare baloxavir with oseltamivir, zanamivir, laninamivir and peramivir in HR patients and all uncomplicated patients.

RESULTS

Based on the SLR, a total of 32 studies were identified as pertinent for the analysis, including 7 studies on HR patients, 13 trials on OwH patients and 14 studies on OwH + HR population. NMA of 10 trials assessing HR patients demonstrated comparable time to alleviation of symptoms for all treatments. Mean decline in virus titer from baseline at 24 h after treatment was significantly greater for baloxavir compared with oseltamivir and peramivir. The risks of total complications and drug-related adverse events were comparable between baloxavir and zanamivir, oseltamivir and laninamivir. These findings were highly consistent with results of the NMA using pooled evidence on the uncomplicated population of OwH and HR patients.

Conclusions: Baloxavir was significantly more effective than placebo regarding all outcomes except for the risk of pneumonia. Besides, baloxavir was associated with similar clinical efficacy and safety, and superior antiviral activity compared to other antivirals in HR patients, as well as in the entire population of uncomplicated patients with influenza.

[Pharmacotherapy for acute respiratory infections caused by influenza viruses: current possibilities]

Routinely the influenza virus significantly contributes to the formation of the annual incidence of acute respiratory infections, with a peak in winter season. The high level of mutagenic potential of influenza viruses is a standard factor determining the complexity of the rational choice of pharmacotherapy. The upcoming epidemiological season 20202021 brings additional challenges for health care practitioners mediated by the widespread prevalence in the human population of a new infection caused by the SARS-CoV-2 virus affecting the respiratory system among many organs and systems. An adequate choice of pharmacotherapy tools should be based on high efficiency and safety of drugs, with a possible reduction in such negative factors as polypharmacy. This review includes comparative pharmacological characteristics of drugs with activity against RNA viruses, along with parameters of their clinical efficacy.

Estimation of the value of convenience in taking influenza antivirals in Japanese adult patients between baloxavir marboxil and neuraminidase inhibitors using a conjoint analysis

AIMS

Estimating the monetary value of the convenience of using influenza antivirals approved in Japan from a patient perspective using a conjoint analysis.

METHODS

An online survey (August 2020) was performed on individuals aged 20-64 years living in Japan who had taken oral or inhalant antivirals for influenza treatment in the 2018/19 or 2019/20 seasons. Efficacy and safety were assumed to be equivalent among the antivirals. The attributes for the conjoint analysis included route (oral or inhalant), duration, frequency of administration, and out-of-pocket expenses. A conditional logit model was applied as a baseline model. The monetary value of each attribute was calculated by comparing the same utility of the linearly interpolated level of the out-of-pocket attribute. Another survey to determine the experiences of the latest antiviral intake was also conducted on the same respondents.

RESULTS

Of the respondents, 1,550 were men and 1,587 were women. The monetary value for oral antivirals was estimated to be higher, saving JPY 741 (USD 7.06, as of August 2020), compared with inhalant. Regarding the length and frequency of administration, five days corresponds to an increase of JPY 2,072, compared with one day, and twice a day corresponds to a JPY 574 increase compared to once a day.

CONCLUSIONS

The results suggest that - among the antivirals approved in Japan - the monetary value of the utility is the highest in the single dose oral antiviral, baloxavir marboxil (baloxavir). Although the drug cost was highest in baloxavir among the brand antivirals, the difference in the value of utility for influenza patient was estimated to be larger than the difference in the drug costs.

LIMITATIONS

Although individuals with diverse attributes from all over the country were included in the survey, they are not necessarily a representative population of the Japanese society.

Baloxavir treatment of ferrets infected with influenza A(H1N1)pdm09 virus reduces onward transmission

Influenza viruses cause seasonal outbreaks and pose a continuous pandemic threat. Although vaccines are available for influenza control, their efficacy varies each season and a vaccine for a novel pandemic virus manufactured using current technology will not be available fast enough to mitigate the effect of the first pandemic wave. Antivirals can be effective against many different influenza viruses but have not thus far been used extensively for outbreak control. Baloxavir, a recently licensed antiviral drug that targets the influenza virus endonuclease, has been shown to reduce virus shedding more effectively than oseltamivir, a widely used neuraminidase inhibitor drug. Thus it is possible that treatment with baloxavir might also interrupt onward virus transmission. To test this, we utilized the ferret model, which is the most commonly used animal model to study influenza virus transmission. We established a subcutaneous baloxavir administration method in ferrets which achieved similar pharmacokinetics to the approved human oral dose. Transmission studies were then conducted in two different locations with different experimental setups to compare the onward transmission of A(H1N1)pdm09 virus from infected ferrets treated with baloxavir, oseltamivir or placebo to naïve sentinel ferrets exposed either indirectly in adjacent cages or directly by co-housing. We found that baloxavir treatment reduced infectious viral shedding in the upper respiratory tract of ferrets compared to placebo, and reduced the frequency of transmission amongst sentinels in both experimental setups, even when treatment was delayed until 2 days post-infection. In contrast, oseltamivir treatment did not substantially affect viral shedding or transmission compared to placebo. We did not detect the emergence of baloxavir-resistant variants in treated animals or in untreated sentinels. Our results support the concept that antivirals which decrease viral shedding could also reduce influenza transmission in the community.

Curative efficacy and safety of peramivir in the treatment of children suspected with influenza

The data from a total of 200 children with suspected influenza virus infection were assessed at the febrile clinic of Women and Children’s hospital in Ganzhou of Jiangxi province from January 2018 to March 2019, and the patients were belonged to two groups (peramivir treatment group and oseltamivir treatment group). At the same time, 100 patients without special treatment were evaluated as the control group. We observed the patients’ fever relief time, pharyngeal pain relief time, nasal congestion relief time, runny nose symptoms relief time, days of hospitalization, days of medication, cost of medication, and adverse reactions in the three groups. We analyzed and compared the efficacy and adverse reactions of peramivir and oseltamivir in the treatment of children suspected with influenza. The recovery of body temperature, relief of cough, days of medication, and hospitalization period in the peramivir group were significantly shorter compared to the oseltamivir and control groups. The mean times to alleviation of fever in the three groups were 18.28 ± 17.74 h (peramivir group), 48.20 ± 34.28 h (oseltamivir group), and 72.56 ± 25.78 h (control group). The mean times to alleviation of cough in the three groups were 49.77 ± 27.58 h (peramivir group), 68.53 ± 32.54 h (oseltamivir group), and 59.38 ± 31.26 (control group). The cost of the peramivir group was significantly higher than that of the oseltamivir and control groups. The incidence of drug reactions in the peramivir group was significantly lower than that in the oseltamivir group. The rate of antibiotic usage in the peramivir group was significantly lower than that in the oseltamivir and control groups. Peramivir can significantly alleviate symptoms and reduce the use of antibiotics in children with suspected influenza. Peramivir has demonstrated good efficacy, high safety, and good compliance in treating children with suspected influenza infection.