Comparison of Hospitalization Incidence in Influenza Outpatients Treated With Baloxavir Marboxil or Neuraminidase Inhibitors: A Health Insurance Claims Database Study

Discovery of natural multi-targets neuraminidase inhibitor glycosides compounds against influenza A virus through network pharmacology, virtual screening, molecular dynamics simulation, and in vitro experiment

Influenza virus continually challenges both human and animal health. Moreover, influenza viruses are easy to mutate. In a certain degree, vaccines may not catch up with rapid mutant paces of viruses. Anti-influenza drugs NIs (neuraminidase inhibitors) are one of the best choices. Therefore, based on ADMET properties, eight optimal natural multi-targets NIs glycosides compounds (IC50  = 0.094-97.275 μM) are found from radix glycyrrhizae, flos sophorae, caulis spatholobi, radix astragali, radix glycyrrhizae, semen astragali complanati, and common fenugreek seed through network pharmacology, molecular docking, dynamics simulation, quantum chemistry, and in vitro experiment. Moreover, mechanism research illustrates these natural compounds treat influenza A virus through key targets TLR4, TNF, and IL6 (high fever, acute respiratory distress syndrome), MAPK1, and MAPK3 (MAPK signaling pathway, viral RNP export, and viral protein expression), IL1B (NOD-like receptor signaling pathway, suppressed maturation of pro-IL-1β and pro-IL-18), CASP3 (apoptosis), AKT1 (inhibited premature apoptosis), and EP300 (viral myocarditis, chemoattraction of monocytes and macrophages, T-cell activation antibody response).

Treatment and prevention of influenza in geriatric patients

INTRODUCTION

Older adults are the most vulnerable population to the effects of influenza. These patients have age-related characteristics that make response to both infection and therapeutics different than younger patients.

AREAS COVERED

Influenza vaccination and antiviral therapy are the foundational approaches to preventing and treating influenza in geriatric patients. Older adults should receive one of the three enhanced vaccines before influenza season beings. There are five antivirals used in influenza. Geriatric patients have been under-enrolled in antiviral studies but have been included in small numbers. Oseltamivir has the most abundant evidence, including in the hospital and long-term care (LTC) facilities, and the strongest evidence for reducing mortality and complications. Peramivir offers the shortest time for symptom alleviation, while baloxavir is best tolerated.

EXPERT OPINION

Oseltamivir has the most versatility in preventing and treating influenza in geriatric patients. Parenteral peramivir and zanamivir are second-line alternatives for complicated influenza when oseltamivir cannot be used. Single-dose peramivir and baloxavir are attractive alternatives to oseltamivir in uncomplicated influenza but will not increase in utilization until more evidence is available regarding mortality and complications, particularly in hospitalized and LTC patients. More studies, including comparative trials, are required to elucidate the role in therapy for each therapeutic in the geriatric population.

Factors Associated With the Development of Bacterial Pneumonia Related to Seasonal Influenza Virus Infection: A Study Using a Large-scale Health Insurance Claim Database

Background

Influenza-related bacterial pneumonia is a leading complication of influenza infection. However, the differences in the incidence rates and risk factors associated with concomitant viral/bacterial pneumonia (CP) and secondary bacterial pneumonia following influenza (SP) remain unclear. This study aimed to clarify the incidence rates of CP and SP following seasonal influenza and identify factors associated with their development.

Methods

This retrospective cohort study was conducted using the JMDC Claims Database, a health insurance claims database in Japan. All patients aged <75 years who developed influenza during 2 consecutive epidemic seasons, 2017/2018 and 2018/2019, were analyzed. CP was defined as bacterial pneumonia diagnosed between 3 days before and 6 days after the date of influenza diagnosis, and SP was defined as pneumonia diagnosed 7-30 days after the date of diagnosis. Multivariable logistic regression analyses were performed to identify factors associated with the development of CP and SP.

Results

Among the 10 473 014 individuals registered in the database, 1 341 355 patients with influenza were analyzed. The average age at diagnosis (SD) was 26.6 (18.6) years. There were 2901 (0.22%) and 1262 (0.09%) patients who developed CP and SP, respectively. Age 65-74 years, asthma, chronic bronchitis/emphysema, cardiovascular disease, renal disease, malignant tumor, and immunosuppression were significant risk factors for both CP and SP, whereas cerebrovascular disease, neurological disease, liver disease, and diabetes were risk factors specific to CP development.

Conclusions

The results determined the incidence rates of CP and SP and identified their risk factors, such as older age and comorbidities.

Influenza antivirals and their role in pandemic preparedness

Effective antivirals provide crucial benefits during the early phase of an influenza pandemic, when vaccines are still being developed and manufactured. Currently, two classes of viral protein-targeting drugs, neuraminidase inhibitors and polymerase inhibitors, are approved for influenza treatment and post-exposure prophylaxis. Resistance to both classes has been documented, highlighting the need to develop novel antiviral options that may include both viral and host-targeted inhibitors. Such efforts will form the basis of management of seasonal influenza infections and of strategic planning for future influenza pandemics. This review focuses on the two classes of approved antivirals, their drawbacks, and ongoing work to characterize novel agents or combination therapy approaches to address these shortcomings. The importance of these topics in the ongoing process of influenza pandemic planning is also discussed.

Baloxavir Treatment Delays Influenza B Virus Transmission in Ferrets and Results in Limited Generation of Drug-Resistant Variants

Clinical efficacy of the influenza antiviral baloxavir marboxil (baloxavir) is compromised by treatment-emergent variants harboring a polymerase acidic protein I38T (isoleucine-38-threonine) substitution. However, the fitness of I38T-containing influenza B viruses (IBVs) remains inadequately defined. After the pharmacokinetics of the compound were confirmed in ferrets, animals were injected subcutaneously with 8 mg/kg of baloxavir acid (BXA) at 24 h postinoculation with recombinant BXA-sensitive (BXA-Sen, I38) or BXA-resistant (BXA-Res, I38T) B/Brisbane/60/2008 (Victoria lineage) virus. BXA treatment of donor ferrets reduced virus replication and delayed transmission of the BXA-Sen but not the BXA-Res IBV. The I38 genotype remained dominant in the BXA-Sen-infected animals, even with BXA treatment. In competitive-mixture experiments, no transmission to aerosol contacts was seen from BXA-treated donors coinfected with the BXA-Sen and BXA-Res B/Brisbane/60/2008 viruses. However, in parallel mixed infections with the B/Phuket/3073/2013 (Yamagata lineage) virus background, BXA treatment failed to block airborne transmission of the BXA-Res virus, and the I38T genotype generally predominated. Therefore, the relative fitness of BXA-Res IBVs is complex and dependent on the virus backbone and within-host virus competition. BXA treatment of single-virus-infected ferrets hampers aerosol transmission of the BXA-Sen virus and does not readily generate BXA-Res variants, whereas mixed infections may result in propagation of BXA-Res IBVs of the Yamagata lineage. Our findings confirm the antiviral potency of baloxavir against IBVs, while supporting optimization of the dosing regimen to maximize clinical benefit.

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.