baloxavir marboxil / Generic mfg. - LARVOL DELTA

Baloxavir marboxil versus oseltamivir phosphate: Efficacy, safety, and economics in patients with influenza. (PubMed, Int J Clin Pharmacol Ther) - "Baloxavir marboxil is superior to oseltamivir in efficacy, safety, and cost-effectiveness for influenza."

Journal • Infectious Disease • Influenza • Respiratory Diseases

Perspectives for pharmaceutical screening at XFEL sources using the example of Lassa virus endonuclease. (PubMed, Acta Crystallogr D Struct Biol) - "We collected serial fixed-target X-ray diffraction data at Linac Coherent Light Source and at the synchrotron source PETRA III for comparison and solved the crystal structures of 2,4-dioxo-4-phenylbutanoic acid (DPBA) and baloxavir acid (BXA) binding to the active site of LASVendoN...To analyse the sample throughput in a compound-screening experiment at an XFEL, we further present data for the bacterial fosfomycin-resistance protein A with six ligands previously identified in a synchrotron screening experiment. In summary, the XFEL and synchrotron data-collection approaches have proven to be useful for compound screening with minor differences in achievable data quality and resolution. The individual experimental setup, detector and potentially the use of beam sweeping at XFELs at close-to-physiological temperatures combined with reasonable sample consumption and minimized radiation damage are considered to be advantageous for high-throughput drug development."

Journal • Infectious Disease

Baloxavir marboxil versus oseltamivir for influenza A in children aged 5 years and older: a community-based prospective cohort study. (PubMed, BMC Infect Dis) - "In community-dwelling children with influenza A, baloxavir marboxil was associated with more rapid fever resolution than oseltamivir. Exploratory findings suggested potential benefits regarding viral clearance, complications, healthcare utilization, and tolerability. Because treatment selection was preference-based and open-label, and because influenza A subtype and reduced-susceptibility substitutions were not evaluated, these findings should be interpreted as hypothesis-generating rather than causal."

Journal • Observational data • Infectious Disease • Influenza • Pediatrics • Respiratory Diseases • CD4 • CD8

A Cluster of Influenza A(H3N2) Viruses in 2024 From Tasmania, Australia, With Reduced Susceptibility to Baloxavir. (PubMed, Influenza Other Respir Viruses) - "When the PA-A37T and PA-I38T substitutions were combined and tested in IRINA assay, eightfold higher inhibition was seen compared to PA-I38T alone. On-going monitoring of influenza viruses for reduced susceptibility to antivirals remains an important part of seasonal and zoonotic influenza surveillance."

Journal • Infectious Disease • Influenza • Respiratory Diseases

Anti-influenza and anti-COVID-19 drugs promote bacterial antibiotic cross-resistance through drug-specific adaptive pathways. (PubMed, Environ Pollut) - "Here, we investigated the antibacterial off-target effects of four clinically used anti-IFV/COV drugs-baloxavir acid (BXA), favipiravir (FAV), nirmatrelvir/ritonavir (NMV/r), and oseltamivir phosphate (OSV)-and their potential to influence bacterial stress responses and antibiotic cross-resistance in Escherichia coli, Bacillus subtilis, and Pseudomonas aeruginosa PAO1. Comparative transcriptomic analysis further revealed that cross-resistance did not arise from a universal resistance pathway, but from drug-specific adaptive remodeling, including transporter and metabolic responses under BXA, sporulation/biofilm-associated developmental responses under NMV/r, and a more limited response to OSV. Together, this study provides initial systematic evidence that clinically used anti-IFV/COV drugs can directly perturb bacterial physiology and promote antibiotic cross-resistance under both elevated and environmentally relevant exposure scenarios, identifying antiviral..."

Journal • Infectious Disease • Influenza • Novel Coronavirus Disease • Respiratory Diseases

Pearlstone: A Study to Confirm Efficacy of a Single Dose of Baloxavir Marboxil in the Post-exposure Prophylaxis (PEP) of Influenza Virus Infection in Chinese Participants (clinicaltrials.gov) - P3 | N=325 | Not yet recruiting | Sponsor: Hoffmann-La Roche

New P3 trial • Infectious Disease • Influenza • Respiratory Diseases

Small molecule inhibition of the mitochondrial lipid transfer protein STARD7 attenuates influenza viral replication. (PubMed, PLoS Pathog) - "Combining M4 with baloxavir enhances antiviral efficacy in a murine infection model, providing in vivo support for a host-directed therapeutic strategy. Together, these results identify STARD7 as a metabolic checkpoint licensing vRNP nuclear export and they establish a proof of concept for therapeutic intervention with small molecule inhibitors."

Journal • Infectious Disease • Influenza • Respiratory Diseases

Clinical Impact of Baloxavir-Induced PA I38T/M Substitutions in Diverse Influenza Populations: A Systematic Review and Meta-Analysis. (PubMed, Virus Res) - "PA I38T/M substitutions are associated with noteworthy virological rebound and delayed clinical recovery, predominantly in pediatric populations. These findings emphasize the requirement for age-specific resistance monitoring and support the evaluation of combination antiviral therapies to mitigate resistance emergence."

Journal • Retrospective data • Infectious Disease • Influenza • Pediatrics • Respiratory Diseases

Baloxavir marboxil-related information on Douyin and Xiaohongshu: a cross-sectional analysis of content, misinformation, and user engagement. (PubMed, Naunyn Schmiedebergs Arch Pharmacol) - "Future efforts should focus on characterizing misinformation related to baloxavir marboxil on short video platforms. Additionally, social media platforms should establish policies to review and monitor health education content to ensure the public receives accurate and trustworthy health information."

Journal • Infectious Disease • Influenza • Respiratory Diseases

Association of Baloxavir Treatment Timing with Serial Interval and Household Transmission of Influenza through a Likelihood-Based Analysis. (PubMed, Int J Infect Dis) - "Our findings highlight that baloxavir treatment is associated with a shorter serial interval and lower estimated secondary household transmission risk. We provide model-based estimates suggesting that earlier administration is associated with a greater reduction in serial interval density and estimated transmission risk, which may inform public health strategies for infection control."

Journal • Infectious Disease • Influenza • Respiratory Diseases

Report on influenza viruses received and tested by the Melbourne WHO Collaborating Centre for Reference and Research on Influenza during 2025. (PubMed, Commun Dis Intell (2018)) - "Of 3,307 samples tested for susceptibility to the neuraminidase inhibitors oseltamivir and zanamivir, 37 A(H1N1)pdm09 viruses showed highly reduced inhibition by oseltamivir and no influenza viruses tested showed highly reduced inhibition by zanamivir. Of 5,080 samples with sequencing of the polymerase acidic (PA) gene, no genetic markers associated with highly reduced susceptibility to baloxavir marboxil were identified."

Journal • Infectious Disease • Influenza • Respiratory Diseases

Discovery of small-molecule inhibitors of influenza M1 protein assembly | Poster Board #1233 (ACS-Fall 2026) - "Current influenza antivirals pose significant side effects and face antiviral resistance from pandemic influenza, as seen in oseltamivir and baloxavir. However, there is a new emerging class of capsid-inhibiting antivirals that has demonstrated efficacy in HIV treatment, as exemplified by Lenacapavir...Primary cytotoxicity tests revealed three nontoxic compounds; pharmacokinetic profiling demonstrated low clearance and no observable toxicity in preliminary in vivo assessment. This study establishes M1 conformational modulation as a viable antiviral strategy, supporting the development of capsid-targeting therapeutics with the potential of overcoming resistance associated with current influenza antivirals."

Human Immunodeficiency Virus • Infectious Disease • Influenza • Respiratory Diseases

COMbination therapy with baloxavir and oseltamivir 1 for hospitalized patients with influenza: The pragmatic COMBO 1 randomized controlled trial. (PubMed, Antivir Ther) - "Median TCVS with quantitative PCR (RT-qPCR) was 115.6 and 34.4 hours (p=0.24); % achieving viral negative by RT-qPCR was 33.3% and 75.0% (p=0.28), respectively.ConclusionsCombination therapy with oseltamivir and a single dose of baloxavir was inconclusive with non-significant trends towards shorter median TCVS vs. monotherapy with oseltamivir in hospitalized patients with influenza. Interpretation is limited by small sample size and early termination."

Clinical • Journal • Infectious Disease • Influenza • Respiratory Diseases

Parameterization of the PA endonuclease catalytic center reveals the dynamics of clinically relevant mutations | Poster Board #1002 (ACS-Fall 2026) - "Baloxavir marboxil (BXM), a prodrug of baloxavir acid (BXA), is a first-line antiviral for IAV that targets the highly conserved PA N-terminal endonuclease domain (PAN) of the viral polymerase, blocking the cap-snatching process necessary to prime viral transcription...Our results reveal how resistance mutations remodel PAN conformational dynamics to weaken BXA binding. These findings provide both methodological guidance for metalloprotein modeling and mechanistic insights into antiviral resistance, informing the rational design of next-generation anti-influenza agents."

Clinical • Infectious Disease • Influenza • Respiratory Diseases

A randomised, open-label clinical study on the efficacy of baloxavir marboxil and oseltamivir for post-exposure prevention of influenza in a hospital setting: a study protocol. (PubMed, BMJ Open) - P=N/A | "The full protocol, de-identified participant data and statistical code will be openly available in a public repository within 12 months after trial completion. NCT06762587."

Clinical protocol • Journal • Infectious Disease • Influenza • Respiratory Diseases

Adaptive Platform Trial of Treatments for Respiratory Infections in Community Settings (TreatResp) (clinicaltrials.gov) - P3 | N=264 | Recruiting | Sponsor: Unity Health Toronto | Not yet recruiting ➔ Recruiting | Initiation date: Jan 2026 ➔ Apr 2026

Enrollment open • Trial initiation date • Infectious Disease • Influenza • Respiratory Diseases

Emergence and Genomic Characterisation of Influenza Virus A(H3N2) Subclade K in Saudi Arabia: Dominant Circulation With Fixed HA1 Substitutions and High-Frequency HA-NA Clade Association, 2025-2026. (PubMed, J Med Virol) - "No neuraminidase-inhibitor or baloxavir resistance markers were detected. These data document a K-clade-predominant epidemic with persistent J.2.4 co-circulation, within-season HA-NA reassortment, and marked HA1 divergence from the vaccine reference, against a background of fully susceptible antiviral genotypes."

Journal • Infectious Disease • Influenza • Respiratory Diseases

Whole genome sequencing of influenza virus transmission pairs confirms the efficacy of baloxavir in reducing household transmission. (PubMed, Clin Infect Dis) - "Application of a stringent, sequence-based cutoff for defining true household pairs supports the outcome of the primary endpoint of CENTERSTONE. Baloxavir treatment of influenza cases can reduce influenza virus transmission in households."

Journal • Infectious Disease • Influenza • Respiratory Diseases

From neuraminidase inhibitors to novel mechanisms: expanding therapeutic strategies against influenza. (PubMed, Front Cell Infect Microbiol) - "Suraxavir marboxil, ZX-7101A, and the first approved polymerase basic protein 2 (PB2) inhibitor, onradivir, confirm that scaffold-level optimization (incremental structural refinement within an existing drug class) can meaningfully reduce resistance emergence rates. For H5N1, preparedness relies on a single observationally supported drug class; baloxavir is absent from most national stockpiles, and no randomized trial data exists for any antiviral in human H5N1 infection. Adaptive trial infrastructure, diversified stockpiling to include next-generation CENIs, and equitable global antiviral access are the most urgent priorities in influenza therapeutics."

Journal • Review • Infectious Disease • Influenza • Respiratory Diseases

Detection and characterization of antiviral-resistant viruses during the influenza season of 2024-25. (PubMed, Microbiol Spectr) - "In the US, three oseltamivir-resistant A(H3N2) viruses had treatment-emergent neuraminidase (NA) mutations, either E119V or R292K...Influenza polymerase acidic (PA) mutations conferring 4- to 92-fold decreased baloxavir susceptibility were detected in nine influenza A viruses...However, CDC laboratory is the only laboratory in the US conducting phenotypic testing of circulating viruses needed to confirm the outcomes of sequence-based analysis and to identify new molecular markers of resistance. Data gathered through virologic surveillance give much-needed information on drug susceptibility of influenza viruses which are used to guide recommendations on antiviral use."

Journal • Infectious Disease • Influenza • Respiratory Diseases

Identification of related substances in baloxavir marboxil using 2D-LC-Q-TOF/MS. (PubMed, J Pharm Biomed Anal) - "Furthermore, a preliminary genotoxicity assessment of the characterized impurities was conducted in accordance with the ICH M7(R2) guideline using in-silico (Q)SAR prediction approaches, and revealed that these related substances did not exhibit genotoxic structural alerts. The determined impurity profile of baloxavir marboxil and the evaluated impurities' potential safety risks can provide a valuable reference for its impurity control, stability evaluation, and quality risk management."

Journal • Infectious Disease • Influenza • Respiratory Diseases

Baloxavir marboxil, favipiravir, or oseltamivir in patients with non-severe symptomatic seasonal influenza (AD ASTRA): a phase 2, open-label, adaptive, randomised controlled trial. (PubMed, Lancet Infect Dis) - P2 | "Oral baloxavir, favipiravir, and oseltamivir accelerated influenza viral clearance rates in adults with early non-severe seasonal influenza at low risk of progression to severe disease. Baloxavir had the greatest in-vivo antiviral efficacy, followed by favipiravir and oseltamivir. These antivirals shortened fever duration but showed no clear effects on time to complete symptom resolution. This pharmacometric approach can inform prioritisation of antiviral agents for further study and potential inclusion in pandemic stockpiles."

Journal • P2 data • CNS Disorders • Infectious Disease • Influenza • Respiratory Diseases

The global demand and potential public health impact of oral antiviral treatment stockpile for influenza pandemics. (PubMed, Proc Natl Acad Sci U S A) - "We find that baloxavir marboxil (BXM), due to its transmission-reducing potential, could avert 37 to 68% of mean pandemic deaths in the first epidemic wave, approximately double the impact of oseltamivir, while requiring a mean stockpile approximately 5 to 10% smaller (7 to 34% of the population, compared to 28 to 36% for oseltamivir). Although drug rationing for high-mortality populations (e.g., elderly) can substantially reduce BXM demand, doing so leads to greater total pandemic deaths. Critically, each week of delay in initiating antiviral distribution erodes impact by up to 3% of averted deaths, meaning that antiviral stockpiles must be accompanied by rapid deployment infrastructure to deliver their potential impact."

Journal • Infectious Disease • Influenza • Novel Coronavirus Disease • Respiratory Diseases

Parameterization of the PA Endonuclease Bimetallic Center Reveals the Dynamics of Clinically Relevant Mutations. (PubMed, J Chem Theory Comput) - "As the latest addition to anti-influenza therapy, baloxavir marboxil (BXM) targets the highly conserved PA N-terminal endonuclease domain (PAN), blocking the cap-snatching process essential for viral transcription initiation...Identification of reliable parametrization schemes enabled MD simulations of five clinically relevant mutants, I38T/F/M, A36V, and E23K, revealing how each reshapes the conformational landscape to modulate drug-binding modes. Together, our results provide a path toward modeling complex sites in metalloenzymes and a mechanistic foundation for vulnerabilities in PAN to guide structure-based optimization of next-generation inhibitors."

Journal • Infectious Disease • Influenza • Respiratory Diseases

Antiviral Dispensing for Influenza Outpatients Younger Than 65 Years With Comorbidities: A Retrospective Cohort Study. (PubMed, Open Forum Infect Dis) - "Antiviral treatment was defined as dispensing of oseltamivir, peramivir, zanamivir, or baloxavir within 7 days of the encounter...About half of higher-risk influenza outpatients received antivirals. Overall dispensing was similar by insurance type, but Medicaid patients and those with multiple UMCs had greater delays."

Journal • Retrospective data • Infectious Disease • Influenza • Pulmonary Disease • Respiratory Diseases