Rutin prevents EqHV-8 induced infection and oxidative stress via Nrf2/HO-1 signaling pathway.

Introduction: The Nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling pathway has been extensively studied for its role in regulating antioxidant and antiviral responses. The Equid herpesvirus type 8 (EqHV-8) poses a significant threat to the equine industry, primarily manifesting as respiratory disease, abortions, and neurological disorders in horses and donkeys. Oxidative stress is considered a key factor associated with pathogenesis of EqHV-8 infection. Unfortunately, there is currently a dearth of therapeutic interventions available for the effective control of EqHV-8. Rutin has been well documented for its antioxidant and antiviral potential. In current study we focused on the evaluation of Rutin as a potential therapeutic agent against EqHV-8 infection. Methods: For this purpose, we encompassed both in-vitro and in-vivo investigations to assess the effectiveness of Rutin in combatting EqHV-8 infection. Results and Discussion: The results obtained from in vitro experiments demonstrated that Rutin exerted a pronounced inhibitory effect on EqHV-8 at multiple stages of the viral life cycle. Through meticulous experimentation, we elucidated that Rutin's antiviral action against EqHV-8 is intricately linked to the Nrf2/HO-1 signaling pathway-mediated antioxidant response. Activation of this pathway by Rutin was found to significantly impede EqHV-8 replication, thereby diminishing the viral load. This mechanistic insight not only enhances our understanding of the antiviral potential of Rutin but also highlights the significance of antioxidant stress responses in combating EqHV-8 infection. To complement our in vitro findings, we conducted in vivo studies employing a mouse model. These experiments revealed that Rutin administration resulted in a substantial reduction in EqHV-8 infection within the lungs of the mice, underscoring the compound's therapeutic promise in vivo. Conclusion: In summation, our finding showed that Rutin holds promise as a novel and effective therapeutic agent for the prevention and control of EqHV-8 infections.

Study protocol for assessment of the efficacy of calcium dobesilate versus placebo on SARS-CoV-2 viral load in outpatients with COVID-19 (CADOVID study): a randomised, placebo-controlled, double-blind, monocentric phase II trial.

INTRODUCTION: SARS-CoV-2 mainly infects respiratory endothelial cells, which is facilitated through its spike protein binding to heparan sulphate. Calcium dobesilate (CaD) is a well-established, widely available vasoactive and angioprotective drug interacting with heparan sulphate, with the potential to interfere with the uptake of SARS-CoV-2 by epithelial cells. The CADOVID trial aims to evaluate the efficacy and safety of CaD in reducing the SARS-CoV-2 viral load in non-hospitalised adult patients diagnosed with COVID-19, confirmed by a positive SARS-CoV-2 PCR, including its efficacy to reduce the impact of persistent COVID-19 symptoms. METHODS AND ANALYSIS: This is a randomised, placebo-controlled, double-blind, monocentric phase II trial. Enrolment began in July 2022. A total of 74 adult patients will be randomly allocated to the CaD arm or the placebo group with a 1:1 ratio, respectively. Participants in the intervention arm will receive two capsules of CaD 500 mg two times per day and the placebo arm will receive two matching capsules of mannitol 312.5 mg two times per day, with a treatment period of 7 days for both arms, followed by a 77-day observational period without treatment administration. Participants will be asked to complete secured online questionnaires using their personal smartphone or other electronic device. These include a COVID-19 questionnaire (assessing symptoms, temperature measurement, reporting of concomitant medication and adverse events), a COVID-19 persistent symptoms' questionnaire and the Short Form 12-Item (SF-12) survey. SARS-CoV-2 PCR testing will be performed on nasopharyngeal swabs collected on days 1, 4, 8 and 21. The primary endpoint is the reduction from baseline of SARS-CoV-2 viral load determined by RT-PCR at day 4. ETHICS AND DISSEMINATION: This trial has received approval by the Geneva Regional Research Ethics Committee (2022-00613) and Swissmedic (701339). Dissemination of results will be through presentations at scientific conferences and publication in scientific journals. TRIAL REGISTRATION NUMBER: NCT05305508; Clinicaltrials.gov; Swiss National Clinical Portal Registry (SNCTP 000004938).

Inhibition of caspase pathways limits CD4+ T cell loss and restores host anti-retroviral function in HIV-1 infected humanized mice with augmented lymphoid tissue.

The study of HIV infection and pathogenicity in physical reservoirs requires a biologically relevant model. The human immune system (HIS) mouse is an established model of HIV infection, but defects in immune tissue reconstitution remain a challenge for examining pathology in tissues. We utilized exogenous injection of the human recombinant FMS-like tyrosine kinase 3 ligand (rFLT-3 L) into the hematopoietic stem cell (HSC) cord blood HIS mouse model to significantly expand the total area of lymph node (LN) and the number of circulating human T cells. The results enabled visualization and quantification of HIV infectivity, CD4 T cell depletion and other measures of pathogenesis in the secondary lymphoid tissues of the spleen and LN. Treatment with the Caspase-1/4 inhibitor VX-765 limited CD4+ T cell loss in the spleen and reduced viral load in both the spleen and axillary LN. In situ hybridization further demonstrated a decrease in viral RNA in both the spleen and LN. Transcriptomic analysis revealed that in vivo inhibition of caspase-1/4 led to an upregulation in host HIV restriction factors including SAMHD1 and APOBEC3A. These findings highlight the use of rFLT-3 L to augment human immune system characteristics in HIS mice to support investigations of HIV pathogenesis and test host directed therapies, though further refinements are needed to further augment LN architecture and cellular populations. The results further provide in vivo evidence of the potential to target inflammasome pathways as an avenue of host-directed therapy to limit immune dysfunction and virus replication in tissue compartments of HIV+ persons.

No Remdesivir Resistance Observed in the Phase 3 Severe and Moderate COVID-19 SIMPLE Trials.

Remdesivir (RDV) is a broad-spectrum nucleotide analog prodrug approved for the treatment of COVID-19 in hospitalized and non-hospitalized patients with clinical benefit demonstrated in multiple Phase 3 trials. Here we present SARS-CoV-2 resistance analyses from the Phase 3 SIMPLE clinical studies evaluating RDV in hospitalized participants with severe or moderate COVID-19 disease. The severe and moderate studies enrolled participants with radiologic evidence of pneumonia and a room-air oxygen saturation of ≤94% or >94%, respectively. Virology sample collection was optional in the study protocols. Sequencing and related viral load data were obtained retrospectively from participants at a subset of study sites with local sequencing capabilities (10 of 183 sites) at timepoints with detectable viral load. Among participants with both baseline and post-baseline sequencing data treated with RDV, emergent Nsp12 substitutions were observed in 4 of 19 (21%) participants in the severe study and none of the 2 participants in the moderate study. The following 5 substitutions emerged: T76I, A526V, A554V, E665K, and C697F. The substitutions T76I, A526V, A554V, and C697F had an EC50 fold change of ≤1.5 relative to the wildtype reference using a SARS-CoV-2 subgenomic replicon system, indicating no significant change in the susceptibility to RDV. The phenotyping of E665K could not be determined due to a lack of replication. These data reveal no evidence of relevant resistance emergence and further confirm the established efficacy profile of RDV with a high resistance barrier in COVID-19 patients.

HIV transmission dynamics and population-wide drug resistance in rural South Africa.

Despite expanded antiretroviral therapy (ART) in South Africa, HIV-1 transmission persists. Integrase strand transfer inhibitors (INSTI) and long-acting injectables offer potential for superior viral suppression, but pre-existing drug resistance could threaten their effectiveness. In a community-based study in rural KwaZulu-Natal, prior to widespread INSTI usage, we enroled 18,025 individuals to characterise HIV-1 drug resistance and transmission networks to inform public health strategies. HIV testing and reflex viral load quantification were performed, with deep sequencing (20% variant threshold) used to detect resistance mutations. Phylogenetic and geospatial analyses characterised transmission clusters. One-third of participants were HIV-positive, with 21.7% having detectable viral loads; 62.1% of those with detectable viral loads were ART-naïve. Resistance to older reverse transcriptase (RT)-targeting drugs was found, but INSTI resistance remained low (<1%). Non-nucleoside reverse transcriptase inhibitor (NNRTI) resistance, particularly to rilpivirine (RPV) even in ART-naïve individuals, was concerning. Twenty percent of sequenced individuals belonged to transmission clusters, with geographic analysis highlighting higher clustering in peripheral and rural areas. Our findings suggest promise for INSTI-based strategies in this setting but underscore the need for RPV resistance screening before implementing long-acting cabotegravir (CAB) + RPV. The significant clustering emphasises the importance of geographically targeted interventions to effectively curb HIV-1 transmission.

Inhibition of ESCRT-independent extracellular vesicles biogenesis suppresses enterovirus 71 replication and pathogenesis in mice.

Enterovirus 71 (EV71) causes hand-foot-and-mouth disease (HFMD), neurological complications, and even fatalities in infants. Clinically, the increase of extracellular vesicles (EVs) in EV71 patients' serum was highly associated with the severity of HFMD. EV71 boosts EVs biogenesis in an endosomal sorting complex required for transport (ESCRT)-dependent manner to facilitate viral replication. Yet, the impact of EVs-derived from ESCRT-independent pathway on EV71 replication and pathogenesis is highly concerned. Here, we assessed the effects of EV71-induced EVs from ESCRT-independent pathway on viral replication and pathogenesis by GW4869, a neutral sphingomyelinase inhibitor. Detailly, in EV71-infected mice, blockade of the biogenesis of tissue-derived EVs in the presence of GW4869 restored body weight loss, attenuated clinical scores, and improved survival rates. Furthermore, GW4869 dampens EVs biogenesis to reduce viral load and pathogenesis in multiple tissues of EV71-infected mice. Consistently, GW4869 treatment in a human intestinal epithelial HT29 cells decreased the biogenesis of EVs, in which the progeny EV71 particle was cloaked, leading to the reduction of viral infection and replication. Collectively, GW4869 inhibits EV71-induced EVs in an ESCRT-independent pathway and ultimately suppresses EV71 replication and pathogenesis. Our study provides a novel strategy for the development of therapeutic agents in the treatment for EV71-associated HFMD.

Prophylactic Administration of Gut Microbiome Metabolites Abrogated Microglial Activation and Subsequent Neuroinflammation in an Experimental Model of Japanese Encephalitis.

Short-chain fatty acids (SCFAs) are gut microbial metabolic derivatives produced during the fermentation of ingested complex carbohydrates. SCFAs have been widely regarded to have a potent anti-inflammatory and neuro-protective role and have implications in several disease conditions, such as, inflammatory bowel disease, type-2 diabetes, and neurodegenerative disorders. Japanese encephalitis virus (JEV), a neurotropic flavivirus, is associated with life threatening neuro-inflammation and neurological sequelae in infected hosts. In this study, we hypothesize that SCFAs have potential in mitigating JEV pathogenesis. Postnatal day 10 BALB/c mice were intraperitoneally injected with either a SCFA mixture (acetate, propionate, and butyrate) or PBS for a period of 7 days, followed by JEV infection. All mice were observed for onset and progression of symptoms. The brain tissue was collected upon reaching terminal illness for further analysis. SCFA-supplemented JEV-infected mice (SCFA + JEV) showed a delayed onset of symptoms, lower hindlimb clasping score, and decreased weight loss and increased survival by 3 days (p < 0.0001) upon infection as opposed to the PBS-treated JEV-infected animals (JEV). Significant downregulation of inflammatory cytokines TNF-α, MCP-1, IL-6, and IFN-Υ in the SCFA + JEV group relative to the JEV-infected control group was observed. Inflammatory mediators, phospho-NF-kB (P-NF-kB) and iba1, showed 2.08 ± 0.1 and 3.132 ± 0.43-fold upregulation in JEV versus 1.19 ± 0.11 and 1.31 ± 0.11-fold in the SCFA + JEV group, respectively. Tissue section analysis exhibited reduced glial activation (JEV group─42 ± 2.15 microglia/ROI; SCFA + JEV group─27.07 ± 1.8 microglia/ROI) in animals that received SCFA supplementation prior to infection as seen from the astrocytic and microglial morphometric analysis. Caspase-3 immunoblotting showed 4.08 ± 1.3-fold upregulation in JEV as compared to 1.03 ± 0.14-fold in the SCFA + JEV group and TUNEL assay showed a reduced cellular death post-JEV infection (JEV-6.4 ± 1.5 cells/ROI and SCFA + JEV-3.7 ± 0.73 cells/ROI). Our study critically contributes to the increasing evidence in support of SCFAs as an anti-inflammatory and neuro-protective agent, we further expand its scope as a potential supplementary intervention in JEV-mediated neuroinflammation.

Treatment with inhaled aerosolised ethanol reduces viral load and potentiates macrophage responses in an established influenza mouse model.

AIM: Treatment options for viral lung infections are currently limited. We aimed to explore the safety and efficacy of inhaled ethanol in an influenza-infection mouse model. MATERIALS AND METHODS: In a safety and tolerability experiment, 80 healthy female BALB/c mice (20 per group) were exposed to nebulized saline (control) or three concentrations of ethanol (40/60/80% ethanol v/v in water) for 3x30-minute periods, with a two-hour break between exposures. In a separate subsequent experiment, 40 Female BALB/c mice were nasally inoculated with 104.5 plaque-forming units of immediate virulence "Mem71" influenza. Infection was established for 48-h before commencing treatment in 4 groups of 10 mice with either nebulized saline (control) or one of 3 different concentrations of ethanol (40/60/80% ethanol v/v in water) for 3x30-minute periods daily over three consecutive days. In both experiments, mouse behavior, clinical scores, weight change, bronchoalveolar lavage cell viability, cellular composition, and cytokine levels, were assessed 24-h following the final exposure, with viral load also assessed after the second experiment. RESULTS: In uninfected BALB/c mice, 3x30-minute exposures to nebulized 40%, 60%, and 80% ethanol resulted in no significant differences in mouse weights, cell counts/viability, cytokines, or morphometry measures. In Mem71-influenza infected mice, we observed a dose-dependent reduction in viral load in the 80%-treated group and potentiation of macrophage numbers in the 60%- and 80%-treated groups, with no safety concerns. CONCLUSIONS: Our data provides support for inhaled ethanol as a candidate treatment for respiratory infections.

Nicotinic Acetylcholine Receptor Alpha6 Contributes to Antiviral Immunity via IMD Pathway in Drosophila melanogaster.

Currently, insecticides that target nicotinic acetylcholine receptors (nAChR) are widely used. Studies on the sublethal effects of insecticides have found that they can affect the amount of virus in insects. The mechanism by which insecticides affect insect virus load remain unclear. Here, we show that nAChR targeting insecticide can affect viral replication through the immune deficiency (IMD) pathway. We demonstrate that a low dose of spinosad (6.8 ng/mL), acting as an antagonist to Drosophila melanogaster nicotinic acetylcholine receptor α6 (Dα6), significantly elevates Drosophila melanogaster sigmavirus (DMelSV) virus titers in adults of Drosophila melanogaster. Conversely, a high dose of spinosad (50 ng/mL), acting as an agonist to Dα6, substantially decreases viral load. This bidirectional regulation of virus levels is absent in Dα6-knockout flies, signifying the specificity of spinosad's action through Dα6. Furthermore, the knockdown of Dα6 results in decreased expression of genes in the IMD pathway, including dredd, imd, relish, and downstream antimicrobial peptide genes AttA and AttB, indicating a reduced innate immune response. Subsequent investigations reveal no significant difference in viral titers between relish mutant flies and Dα6-relish double mutants, suggesting that the IMD pathway's role in antiviral defense is dependent on Dα6. Collectively, our findings shed light on the intricate interplay between nAChR signaling and the IMD pathway in mediating antiviral immunity, highlighting the potential for nAChR-targeting compounds to inadvertently influence viral dynamics in insect hosts. This knowledge may inform the development of integrated pest management strategies that consider the broader ecological impact of insecticide use.

Favipiravir Treatment Prolongs Survival in a Lethal BALB/c Mouse Model of Ebinur Lake Virus Infection.

Orthobunyavirus is the largest and most diverse genus in the family Peribunyaviridae. Orthobunyaviruses are widely distributed globally and pose threats to human and animal health. Ebinur Lake virus (EBIV) is a newly classified Orthobunyavirus detected in China, Russia, and Kenya. This study explored the antiviral effects of two broad-spectrum antiviral drugs, favipiravir and ribavirin, in a BALB/c mouse model. Favipiravir significantly improved the clinical symptoms of infected mice, reduced viral titer and RNA copies in serum, and extended overall survival. The median survival times of mice in the vehicle- and favipiravir-treated groups were 5 and 7 days, respectively. Favipiravir significantly reduced virus titers 10- to 100-fold in sera at all three time points compared to vehicle-treated mice. And favipiravir treatment effectively reduced the virus copies by approximately 10-fold across the three time points, relative to vehicle-treated mice. The findings expand the antiviral spectrum of favipiravir for orthobunyaviruses in vivo.

Viral clearance as a surrogate of clinical efficacy for COVID-19 therapies in outpatients: a systematic review and meta-analysis.

BACKGROUND: Surrogates of antiviral efficacy are needed for COVID-19. We aimed to investigate the relationship between the virological effect of treatment and clinical efficacy as measured by progression to severe disease in outpatients treated for mild-to-moderate COVID-19. METHODS: In this systematic review and meta-analysis, we searched PubMed, Scopus, and medRxiv from database inception to Aug 16, 2023, for randomised placebo-controlled trials that tested virus-directed treatments (ie, any monoclonal antibodies, convalescent plasma, or antivirals) in non-hospitalised individuals with COVID-19. We only included studies that reported both clinical outcomes (ie, rate of disease progression to hospitalisation or death) and virological outcomes (ie, viral load within the first 7 days of treatment). We extracted summary data from eligible reports, with discrepancies resolved through discussion. We used an established meta-regression model with random effects to assess the association between clinical efficacy and virological treatment effect, and calculated I2 to quantify residual study heterogeneity. FINDINGS: We identified 1718 unique studies, of which 22 (with a total of 16 684 participants) met the inclusion criteria, and were in primarily unvaccinated individuals. Risk of bias was assessed as low in 19 of 22 studies for clinical outcomes, whereas for virological outcomes, a high risk of bias was assessed in 11 studies, some risk in ten studies, and a low risk in one study. The unadjusted relative risk of disease progression for each extra log10 copies per mL reduction in viral load in treated compared with placebo groups was 0·12 (95% CI 0·04-0·34; p<0·0001) on day 3, 0·20 (0·08-0·50; p=0·0006) on day 5, and 0·53 (0·30-0·94; p=0·030) on day 7. The residual heterogeneity in our meta-regression was estimated as low (I2=0% [0-53] on day 3, 0% [0-71] on day 5, and 0% [0-43] on day 7). INTERPRETATION: Despite the aggregation of studies with differing designs, and evidence of risk of bias in some virological outcomes, this review provides evidence that treatment-induced acceleration of viral clearance within the first 5 days after treatment is a potential surrogate of clinical efficacy to prevent hospitalisation with COVID-19. This work supports the use of viral clearance as an early phase clinical trial endpoint of therapeutic efficacy. FUNDING: Australian Government Department of Health, Medical Research Future Fund, and Australian National Health and Medical Research Council.

Oral mouthwashes for asymptomatic to mildly symptomatic adults with COVID-19 and salivary viral load: a randomized, placebo-controlled, open-label clinical trial.

BACKGROUND: Recent randomized clinical trials suggest that the effect of using cetylpyridinium chloride (CPC) mouthwashes on the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral load in COVID-19 patients has been inconsistent. Additionally, no clinical study has investigated the effectiveness of on-demand aqueous chlorine dioxide mouthwash against COVID-19. METHODS: We performed a randomized, placebo-controlled, open-label clinical trial to assess for any effects of using mouthwash on the salivary SARS-CoV-2 viral load among asymptomatic to mildly symptomatic adult COVID-19-positive patients. Patients were randomized to receive either 20 mL of 0.05% CPC, 10 mL of 0.01% on-demand aqueous chlorine dioxide, or 20 mL of placebo mouthwash (purified water) in a 1:1:1 ratio. The primary endpoint was the cycle threshold (Ct) values employed for SARS-CoV-2 salivary viral load estimation. We used linear mixed-effects models to assess for any effect of the mouthwashes on SARS-CoV-2 salivary viral load. RESULTS: Of a total of 96 eligible participants enrolled from November 7, 2022, to January 19, 2023, 90 were accepted for the primary analysis. The use of 0.05% CPC mouthwash was not shown to be superior to placebo in change from baseline salivary Ct value at 30 min (difference vs. placebo, 0.640; 95% confidence interval [CI], -1.425 to 2.706; P = 0.543); 2 h (difference vs. placebo, 1.158; 95% CI, -0.797 to 3.112; P = 0.246); 4 h (difference vs. placebo, 1.283; 95% CI, -0.719 to 3.285; P = 0.209); 10 h (difference vs. placebo, 0.304; 95% CI, -1.777 to 2.385; P = 0.775); or 24 h (difference vs. placebo, 0.782; 95% CI, -1.195 to 2.759; P = 0.438). The use of 0.01% on-demand aqueous chlorine dioxide mouthwash was also not shown to be superior to placebo in change from baseline salivary Ct value at 30 min (difference vs. placebo, 0.905; 95% CI, -1.079 to 2.888; P = 0.371); 2 h (difference vs. placebo, 0.709; 95% CI, -1.275 to 2.693; P = 0.483); 4 h (difference vs. placebo, 0.220; 95% CI, -1.787 to 2.226; P = 0.830); 10 h (difference vs. placebo, 0.198; 95% CI, -1.901 to 2.296; P = 0.854); or 24 h (difference vs. placebo, 0.784; 95% CI, -1.236 to 2.804; P = 0.447). CONCLUSIONS: In asymptomatic to mildly symptomatic adults with COVID-19, compared to placebo, the use of 0.05% CPC and 0.01% on-demand aqueous chlorine dioxide mouthwash did not lead to a significant reduction in SARS-CoV-2 salivary viral load. Future studies of the efficacy of CPC and on-demand aqueous chlorine dioxide mouthwash on the viral viability of SARS-CoV-2 should be conducted using different specimen types and in multiple populations and settings.

Evaluation of the Efficacy and Safety of Tenofovir Disoproxil Fumarate in Intercepting Mother-to-Child Transmission of Hepatitis B Virus.

Vertical transmission of hepatitis B virus (HBV), especially in Asia, is a key target in the global elimination of HBV. This study assessed the effects of tenofovir disoproxil fumarate (TDF) in pregnant women for mother-to-infant transmission of HBV. A total of 122 pregnant women at our hospital met the inclusion criteria for high HBV DNA viral loads. They were randomly divided into TDF-treatment (n=70) and placebo (n=52) groups. Maternal liver function and serum HBV DNA load were tested before and after treatment. Clinical and laboratory data of infants were assayed at delivery and 7-months post-partum visit and compared between the two groups. There was no difference in clinical characteristics of participants between the two groups. There were no significant differences in liver function markers, including alanine aminotransferase, total bilirubin, blood creatinine, and blood urea nitrogen levels before and after TDF treatment. The serum HBV DNA viral load of the TDF-treated group became significantly lower than those of the control group and their own pre-medication levels. Infants showed no significant difference in body growth, including weight, height, head size, and five-min Apgar score. At 7 months after birth, 94.29% of infants in the TDF group and 86.54% of control-group infants had protective HBsAb levels ≥ 10 mIU/ml (p>0.05). The HBV infection rate of infants in the TDF-treated group was lower than that in the non-treated group. In high-HBV-DNA-load pregnant women, TDF administered from 28 weeks gestational age to delivery was associated with a lower risk of mother-to-infant transmission of HBV.

Non-suppressible viraemia during HIV-1 therapy: a challenge for clinicians.

In individuals receiving antiretroviral therapy (ART), persistent low-level viraemia not attributed to suboptimal ART adherence, detrimental pharmacological interactions, or drug resistance is referred to as non-suppressible viraemia (NSV). This Review presents recent findings in the virological characterisation of NSV, revealing that it consists of one or a few identical populations of plasma viruses without signs of evolution. This finding suggests that NSV originates from virus production by expanded HIV-infected cell clones, reflecting the persistence of the HIV reservoir despite ART. We discuss knowledge gaps regarding the management and the clinical consequences of NSV. The prevalence of NSV remains to be precisely determined and there is very little understanding of its effects on virological failure, HIV transmission, secondary inflammation, morbidity, and mortality. This issue, along with the absence of specific recommendations for the management of NSV in HIV clinical guidelines, underscores the complexities involved in treating individuals with NSV.

Pharmacokinetics and safety of coformulated bictegravir, emtricitabine, and tenofovir alafenamide in children aged 2 years and older with virologically suppressed HIV: a phase 2/3, open-label, single-arm study.

BACKGROUND: Coformulated bictegravir, emtricitabine, and tenofovir alafenamide is a single-tablet regimen and was efficacious and well tolerated in children and adolescents with HIV (aged 6 years to <18 years) in a 48-week phase 2/3 trial. In this study, we report data from children aged at least 2 years and weighing 14 kg to less than 25 kg. METHODS: We conducted this open-label, multicentre, multicohort, single-arm study in South Africa, Thailand, Uganda, and the USA. Participants were virologically suppressed children with HIV, aged at least 2 years, weighing 14 kg to less than 25 kg. Participants received bictegravir (30 mg), emtricitabine (120 mg), and tenofovir alafenamide (15 mg) once daily, switching to bictegravir (50 mg), emtricitabine (200 mg), and tenofovir alafenamide (25 mg) upon attaining a bodyweight of at least 25 kg. The study included pharmacokinetic evaluation at week 2 to confirm the dose of coformulated bictegravir, emtricitabine, and tenofovir alafenamide for this weight band by comparing with previous adult data. Primary outcomes were bictegravir area under the curve over the dosing interval (AUCtau) and concentration at the end of the dosing interval (Ctau) at week 2, and incidence of treatment-emergent adverse events and laboratory abnormalities until the end of week 24 in all participants who received at least one dose of bictegravir, emtricitabine, and tenofovir alafenamide. This study is registered with ClinicalTrials.gov, NCT02881320. FINDINGS: Overall, 22 participants were screened (from Nov 14, 2018, to Jan 11, 2020), completed treatment with bictegravir, emtricitabine, and tenofovir alafenamide (until week 48), and entered an extension phase. The geometric least squares mean (GLSM) ratio for AUCtau for bictegravir was 7·6% higher than adults (GLSM ratio 107·6%, 90% CI 96·7-119·7); Ctau was 34·6% lower than adults (65·4%, 49·1-87·2). Both parameters were within the target exposure range previously found in adults, children, or both". Grade 3-4 laboratory abnormalities occurred in four (18%) participants by the end week 24 and six (27%) by the end of week 48. Drug-related adverse events occurred in three participants (14%) by the end of week 24 and week 48; none were severe. No Grade 3-4 adverse events, serious adverse events, or adverse events leading to discontinuation occurred by the end of week 24 and week 48. INTERPRETATION: Data support the use of single-tablet coformulated bictegravir (30 mg), emtricitabine (120 mg), and tenofovir alafenamide (15 mg) for treatment of HIV in children aged at least 2 years and weighing 14 kg to less than 25 kg. FUNDING: Gilead Sciences.

Modeling the emergence of viral resistance for SARS-CoV-2 during treatment with an anti-spike monoclonal antibody.

To mitigate the loss of lives during the COVID-19 pandemic, emergency use authorization was given to several anti-SARS-CoV-2 monoclonal antibody (mAb) therapies for the treatment of mild-to-moderate COVID-19 in patients with a high risk of progressing to severe disease. Monoclonal antibodies used to treat SARS-CoV-2 target the spike protein of the virus and block its ability to enter and infect target cells. Monoclonal antibody therapy can thus accelerate the decline in viral load and lower hospitalization rates among high-risk patients with variants susceptible to mAb therapy. However, viral resistance has been observed, in some cases leading to a transient viral rebound that can be as large as 3-4 orders of magnitude. As mAbs represent a proven treatment choice for SARS-CoV-2 and other viral infections, evaluation of treatment-emergent mAb resistance can help uncover underlying pathobiology of SARS-CoV-2 infection and may also help in the development of the next generation of mAb therapies. Although resistance can be expected, the large rebounds observed are much more difficult to explain. We hypothesize replenishment of target cells is necessary to generate the high transient viral rebound. Thus, we formulated two models with different mechanisms for target cell replenishment (homeostatic proliferation and return from an innate immune response antiviral state) and fit them to data from persons with SARS-CoV-2 treated with a mAb. We showed that both models can explain the emergence of resistant virus associated with high transient viral rebounds. We found that variations in the target cell supply rate and adaptive immunity parameters have a strong impact on the magnitude or observability of the viral rebound associated with the emergence of resistant virus. Both variations in target cell supply rate and adaptive immunity parameters may explain why only some individuals develop observable transient resistant viral rebound. Our study highlights the conditions that can lead to resistance and subsequent viral rebound in mAb treatments during acute infection.

Design of a SARS-CoV-2 papain-like protease inhibitor with antiviral efficacy in a mouse model.

The emergence of SARS-CoV-2 variants and drug-resistant mutants calls for additional oral antivirals. The SARS-CoV-2 papain-like protease (PLpro) is a promising but challenging drug target. We designed and synthesized 85 noncovalent PLpro inhibitors that bind to a recently discovered ubiquitin binding site and the known BL2 groove pocket near the S4 subsite. Leads inhibited PLpro with the inhibitory constant Ki values from 13.2 to 88.2 nanomolar. The co-crystal structures of PLpro with eight leads revealed their interaction modes. The in vivo lead Jun12682 inhibited SARS-CoV-2 and its variants, including nirmatrelvir-resistant strains with EC50 from 0.44 to 2.02 micromolar. Oral treatment with Jun12682 improved survival and reduced lung viral loads and lesions in a SARS-CoV-2 infection mouse model, suggesting that PLpro inhibitors are promising oral SARS-CoV-2 antiviral candidates.

Rilpivirine and cabotegravir trough concentrations in people with HIV on long-term treatment with long-acting injectable antiretrovirals.

OBJECTIVE: Large inter-individual variability in the pharmacokinetics of rilpivirine and cabotegravir has been reported in the first weeks after starting long-acting injectable (LAI) therapy. Here, we assessed the distribution of rilpivirine and cabotegravir trough concentrations in people with HIV (PWH) on long-term LAI treatment. METHODS: Adult PWH treated with LAI for at least 32 weeks with an assessment of drug plasma trough concentrations were considered. The proportion of rilpivirine and cabotegravir plasma trough concentrations below four-times the protein-adjusted concentrations required for 90% inhibition of viral replication (4×PA-IC90) was estimated. RESULTS: Sixty-seven PWH were identified. LAI treatment duration was 216 ±â€Š80 weeks (range 32-320 weeks). Cabotegravir concentrations were associated with lower inter-individual variability compared with rilpivirine (45% versus 84%; P < 0.05). No differences were found in rilpivirine (160 ±â€Š118 versus 189 ±â€Š81 ng/mL; P = 0.430) and cabotegravir (1758 ±â€Š807 versus 1969 ±â€Š802 ng/mL; P = 0.416) trough concentrations in males (n = 55) versus females (n = 12). A non-significant trend for lower cabotegravir concentrations was found in PWH with a body mass index >30 kg/m2 (n = 9) versus non-obese participants (1916 ±â€Š905 versus 1606 ±â€Š576 ng/mL; P = 0.131). Three out of the 67 PWH had at least one drug concentration <4×PA-IC90: 100% of PWH had undetectable HIV viral load. CONCLUSIONS: At steady state, optimal systemic exposure of cabotegravir and rilpivirine was found in most PWH; cabotegravir trough concentrations were associated with lower inter-individual variability compared with rilpivirine. The study was not powered to assess the contribution of sex and/or body weight on LAI exposure due to the small number of females and obese PWH included.

Drug resistance and influencing factors in HIV-1-infected individuals under antiretroviral therapy in Guangxi, China.

OBJECTIVES: To assess the profiles and determinants of drug resistance in HIV-1-infected individuals undergoing ART in Guangxi. METHODS: Samples and data were collected from HIV-1-infected individuals experiencing virological failure post-ART from 14 cities in Guangxi. Sequencing of the HIV-1 pol gene was conducted, followed by analysis for drug resistance mutations using the Stanford University HIV Drug Resistance Database. Logistic regression was employed to identify potential risk factors associated with both HIV drug resistance and mortality. RESULTS: A total of 8963 individuals with pol sequences were included in this study. The overall prevalence of HIV-1 drug resistance (HIVDR) was 42.43% (3808/8963), showing a decrease from 59.62% to 41.40% from 2016 to 2023. Factors such as being aged ≥50 years, male, Han nationality, lower education levels, occupations including workers, peasants and children, AIDS, pre-treatment CD4 T cell counts <200 cells/mm3, infection with CRF01_AE and CRF55_01B subtypes, and ART regimen lamivudine/zidovudine/nevirapine were associated with higher susceptibility to HIVDR. The common mutations were M184V (17.38%) and K103N (22.14%). Additionally, the prevalence of M184V, S68G, M41L and G190A were different between the Han and Zhuang populations. Factors including age, gender, ethnicity, education level, occupation, infectious route, clinical stage, viral load, subtype, ART regimen and HIVDR showed significant associations with mortality. CONCLUSIONS: The factors contributing to drug resistance in the HIV-1 ART individuals in Guangxi appear to be notably intricate. Continuous reinforcement of drug resistance surveillance is imperative, accompanied by the optimization of ART regimens to mitigate virological failures effectively.