Pitfalls in Valganciclovir Prophylaxis Dose Adjustment Based on Renal Function in Kidney Transplant Recipients.

Valganciclovir (VGC) is administered as prophylaxis to kidney transplant recipients (KTR) CMV donor (D)+/recipient (R)- and CMV R+ after thymoglobulin-induction (R+/TG). Although VGC dose adjustments based on renal function are recommended, there is paucity of real-life data on VGC dosing and associations with clinical outcomes. This is a retrospective Swiss Transplant Cohort Study-embedded observational study, including all adult D+/R- and R+/TG KTR between 2010 and 2020, who received prophylaxis with VGC. The primary objective was to describe the proportion of inappropriately (under- or over-) dosed VGC week-entries. Secondary objectives included breakthrough clinically significant CMV infection (csCMVi) and potential associations between breakthrough-csCMVi and cytopenias with VGC dosing. Among 178 KTR, 131 (73.6%) patients had ≥2 week-entries for the longitudinal data of interest and were included in the outcome analysis, with 1,032 VGC dose week-entries. Overall, 460/1,032 (44.6%) were appropriately dosed, while 234/1,032 (22.7%) and 338/1,032 (32.8%) were under- and over-dosed, respectively. Nineteen (14.5%) patients had a breakthrough-csCMVi, without any associations identified with VCG dosing (p = 0.44). Unlike other cytopenias, a significant association between VGC overdosing and lymphopenia (OR 5.27, 95% CI 1.71-16.22, p = 0.004) was shown. VGC prophylaxis in KTR is frequently inappropriately dosed, albeit without meaningful clinical associations, neither in terms of efficacy nor safety.

Population pharmacokinetics and dose rationale for aciclovir in term and pre-term neonates with herpes.

Aciclovir is considered the first-line treatment against Herpes simplex virus (HSV) infections in new-borns and infants. As renal excretion is the major route of elimination, in renally-impaired patients, aciclovir doses are adjusted according to the degree of impairment. However, limited attention has been given to the implications of immature renal function or dysfunction due to the viral disease itself. The aim of this investigation was to characterize the pharmacokinetics of aciclovir taking into account maturation and disease processes in the neonatal population. Pharmacokinetic data obtained from 2 previously published clinical trials (n = 28) were analyzed using a nonlinear mixed effects modeling approach. Post-menstrual age (PMA) and creatinine clearance (CLCR) were assessed as descriptors of maturation and renal function. Simulation scenarios were also implemented to illustrate the use of pharmacokinetic data to extrapolate efficacy from adults. Aciclovir pharmacokinetics was described by a one-compartment model with first-order elimination. Body weight and diagnosis (systemic infection) were statistically significant covariates on the volume of distribution, whereas body weight, CLCR and PMA had a significant effect on clearance. Median clearance varied from 0.2 to 1.0 L/h in subjects with PMA <34 or ≥34 weeks, respectively. Population estimate for volume of distribution was 1.93 L with systemic infection increasing this value by almost 3-fold (2.67 times higher). A suitable model parameterization was identified, which discriminates the effects of developmental growth, maturation, and organ function. Exposure to aciclovir was found to increase with decreasing PMA and renal function (CLCR), suggesting different dosing requirement for pre-term neonates.

Predicting lung exposure of intramuscular niclosamide as an antiviral agent: Power-law based pharmacokinetic modeling.

Niclosamide, a potent anthelmintic agent, has emerged as a candidate against COVID-19 in recent studies. Its formulation has been investigated extensively to address challenges related to systemic exposure. In this study, niclosamide was formulated as a long-acting intramuscular injection to achieve systemic exposure in the lungs for combating the virus. To establish the dose-exposure relationship, a hamster model was selected, given its utility in previous COVID-19 infection studies. Pharmacokinetic (PK) analysis was performed using NONMEM and PsN. Hamsters were administered doses of 55, 96, 128, and 240 mg/kg with each group comprising five animals. Two types of PK models were developed, linear models incorporating partition coefficients and power-law distributed models, to characterize the relationship between drug concentrations in the plasma and lungs of the hamsters. Numerical and visual diagnostics, including basic goodness-of-fit and visual predictive checks, were employed to assess the models. The power-law-based PK model not only demonstrated superior numerical performance compared with the linear model but also exhibited better agreement in visual diagnostic evaluations. This phenomenon was attributed to the nonlinear relationship between drug concentrations in the plasma and lungs, reflecting kinetic heterogeneity. Dose optimization, based on predicting lung exposure, was conducted iteratively across different drug doses, with the minimum effective dose estimated to be ~1115 mg/kg. The development of a power-law-based PK model proved successful and effectively captured the nonlinearities observed in this study. This method is expected to be applicable for investigating the drug disposition of specific formulations in the lungs.

Assessment of effectiveness and impact of universal prophylaxis with nirsevimab for prevention of hospitalizations due to respiratory syncytial virus in infants. The NIRSE-GAL study protocol.

Nirsevimab has been recently licensed for universal RSV prophylaxis in infants. NIRSE-GAL is a three-year population-based study initiated in Galicia in September 2023. It aims to evaluate nirsevimab effectiveness against RSV-related hospitalizations lower respiratory tract infections (LRTI), severe RSV, all-cause LRTI, and all-cause hospitalization. NIRSE-GAL also aims to estimate nirsevimab impact on primary healthcare use in the short and mid-term, children's wheezing and asthma, and medical prescriptions for RSV. The immunization campaigns will be scheduled based on the expected start week for the RSV season and will last the whole season. Immunization will be offered to: i) infants born during the campaign (seasonal), ii) infants < 6 months at the start of the campaign (catch-up), and iii) infants with high-risk factors, aged 6-24 months at the start of the campaign (high-risk). The follow-up period will start: i) the immunization date for all immunized infants, ii) the start of the campaign, for the non-immunized catch-up or high-risk groups, or iii) the birthdate for the non-immunized seasonal group. Infants will be followed up until outcome occurrence, death, or end of study. Nirsevimab effectiveness will be estimated using Poisson and Cox regression models. Sensitivity and stratified analyses will be undertaken. The number of averted cases and the number needed to immunize will be estimated. Immunization failure and nirsevimab safety will be monitored. NIRSE-GAL was approved by the ethics committee of Galicia (CEIC 2023-377) and registered in ClinicalTrials.gov (ID: NCT06180993). Findings will be mainly shared via peer-reviewed publications and scientific conferences.

[Results of a randomized double-blind multicenter clinical trial of the efficacy and safety of the drug riamilovir for the prevention of COVID-19].

AIM: Evaluation of the efficacy and safety of riamilovir as a drug for the prevention of coronavirus infection (COVID-19) in adults who have constant contact with COVID-19 patients as a result of living together. MATERIALS AND METHODS: The study included 750 adult participants living with patients with confirmed polymerase chain reaction method COVID-19, who had a negative polymerase chain reaction result for the SARS-CoV-2 virus at the initial level, met the criteria for inclusion, non-inclusion and exclusion, and signed a voluntary informed consent to participate in a clinical trial. RESULTS: The efficacy, good tolerability and safety of the drug riamilovir for the prevention of COVID-19 infection among people who have come into contact with COVID-19 patients in a family focus of infection have been established. CONCLUSION: As a result of a multicenter randomized double-blind clinical trial, the effectiveness of the drug riamilovir for the prevention of COVID-19 infection was established. It was shown that the relative risk of disease in the group taking riamilovir for prophylaxis was 88.96% lower than in the control group. Based on the results of a clinical trial, in October 2023 Ministry of Health of the Russian Federation approved the inclusion of a new indication (prophylaxis of COVID-19 infection) in the instructions for the medical use of the drug riamilovir (trade name - Triazavirin®).

Olgotrelvir as a Single-Agent Treatment of Nonhospitalized Patients with Covid-19.

BACKGROUND: Olgotrelvir is an oral antiviral with dual mechanisms of action targeting severe acute respiratory syndrome coronavirus 2 main protease (i.e., Mpro) and human cathepsin L. It has potential to serve as a single-agent treatment of coronavirus disease 2019 (Covid-19). METHODS: We conducted a phase 3, double-blind, randomized, placebo-controlled trial to evaluate the efficacy and safety of olgotrelvir in 1212 nonhospitalized adult participants with mild to moderate Covid-19, irrespective of risk factors, who were randomly assigned to receive orally either 600 mg of olgotrelvir or placebo twice daily for 5 days. The primary and key secondary end points were time to sustained recovery of a panel of 11 Covid-19-related symptoms and the viral ribonucleic acid (RNA) load. The safety end point was incidence of treatment-emergent adverse events. RESULTS: The baseline characteristics of 1212 participants were similar in the two groups. In the modified intention-to-treat population (567 patients in the placebo group and 558 in the olgotrelvir group), the median time to symptom recovery was 205 hours in the olgotrelvir group versus 264 hours in the placebo group (hazard ratio, 1.29; 95% confidence interval [CI], 1.13 to 1.46; P<0.001). The least squares mean (95% CI) changes of viral RNA load from baseline were -2.20 (-2.59 to -1.81) log10 copies/ml in olgotrelvir-treated participants and -1.40 (-1.79 to -1.01) in participants receiving placebo at day 4. Skin rash (3.3%) and nausea (1.5%) were more frequent in the olgotrelvir group than in the placebo group; there were no treatment-related serious adverse events, and no deaths were reported. CONCLUSIONS: Olgotrelvir as a single-agent treatment significantly improved symptom recovery. Adverse effects were not dose limiting. (Funded by Sorrento Therapeutics, a parent company of ACEA Therapeutics; ClinicalTrials.gov number, NCT05716425.).

A cost analysis of a simplified model for HCV screening and treatment at a tertiary hospital in Zimbabwe.

BACKGROUND: The treatment of chronic hepatitis C virus (HCV) infection using directly acting antivirals was recently adopted in the treatment guidelines of Zimbabwe. The objectives of this study were to design a simplified model of HCV care and estimate the cost of screening and treatment of hepatitis C infection at a tertiary hospital in Zimbabwe. METHODS: We developed a model of care for HCV using WHO 2018 guidelines for the treatment of HCV infection and expert opinion. We then performed a micro-costing to estimate the costs of implementing the model of care from the healthcare sector perspective. Deterministic and probabilistic sensitivity analyses were performed to explore the impact of uncertainty in input parameters on the estimated total cost of care. RESULTS: The total cost of screening and treatment was estimated to be US$2448 (SD=$290) per patient over a 12-week treatment duration using sofosbuvir/velpatasvir. The cost of directly acting antivirals contributed 57.5% to the total cost of care. The second largest cost driver was the cost of diagnosis, US$819, contributing 34.6% to the total cost of care. CONCLUSION: Screening and treatment of HCV-infected individuals using directly acting antivirals at a tertiary hospital in Zimbabwe may require substantial financial resources.

Four weeks of off-treatment follow-up is sufficient to determine virologic responses at off-treatment week 12 in patients with hepatitis C virus infection receiving fixed-dose pangenotypic direct-acting antivirals.

Early confirmation of sustained virologic response (SVR) or viral relapse after direct-acting antivirals (DAAs) for hepatitis C virus (HCV) infection is essential based on public health perspectives, particularly for patients with high risk of nonadherence to posttreatment follow-ups. A total of 1011 patients who achieved end-of-treatment virologic response, including 526 receiving fixed-dose pangenotypic DAAs, and 485 receiving other types of DAAs, who had available off-treatment weeks 4 and 12 serum HCV RNA data to confirm SVR at off-treatment week 12 (SVR12) or viral relapse were included. The positive predictive value (PPV) and negative predictive value (NPV) of SVR4 to predict patients with SVR12 or viral relapse were reported. Furthermore, we analyzed the proportion of concordance between SVR12 and SVR24 in 943 patients with available SVR24 data. The PPV and NPV of SVR4 to predict SVR12 were 98.5% (95% confidence interval [CI]: 98.0-98.9) and 100% (95% CI: 66.4-100) in the entire population. The PPV of SVR4 to predict SVR12 in patients receiving fixed-dose pangenotypic DAAs was higher than those receiving other types of DAAs (99.8% [95% CI: 98.9-100] vs. 97.1% [95% CI: 96.2-97.8], p < 0.001). The NPVs of SVR4 to predict viral relapse were 100%, regardless of the type of DAAs. Moreover, the concordance between SVR12 and SVR24 was 100%. In conclusion, an off-treatment week 4 serum HCV RNA testing is sufficient to provide an excellent prediction power of SVR or viral relapse at off-treatment week 12 among patients with HCV who are treated with fixed-dose pangenotypic DAAs.

Sustained release delivery of favipiravir through statistically optimized, chemically cross-linked, pH-sensitive, swellable hydrogel.

In the current work, favipiravir (an antiviral drug) loaded pH-responsive polymeric hydrogels were developed by the free redical polymerization technique. Box-Behnken design method via Design Expert version 11 was employed to furnish the composition of all hydrogel formulations. Here, polyethylene glycol (PEG) has been utilized as a polymer, acrylic acid (AA) as a monomer, and potassium persulfate (KPS) and methylene-bisacrylamide (MBA) as initiator and cross-linker, respectively. All networks were evaluated for in-vitro drug release (%), sol-gel fraction (%), swelling studies (%), porosity (%), percentage entrapment efficiency, and chemical compatibilities. According to findings, the swelling was pH sensitive and was shown to be greatest at a pH of 6.8 (2500%). The optimum gel fraction offered was 97.8%. A sufficient porosity allows the hydrogel to load a substantial amount of favipiravir despite its hydrophobic behavior. Hydrogels exhibited maximum entrapment efficiency of favipiravir upto 98%. The in-vitro release studies of drug-formulated hydrogel revealed that the drug release from hydrogel was between 85 to 110% within 24 h. Drug-release kinetic results showed that the Korsmeyer Peppas model was followed by most of the developed formulations based on the R2 value. In conclusion, the hydrogel-based technology proved to be an excellent option for creating the sustained-release dosage form of the antiviral drug favipiravir.

Interim analysis of the PARADISE study: Benefits of add-on peginterferon-α in NA-treated patients with CHB.

This study aimed to investigate whether peginterferon-α (IFN) add-on nucleos(t)ide analogs(NAs) can further reduce hepatocellular carcinoma(HCC) risk compared with NAs monotherapy in NA-treated patients with chronic hepatitis B(CHB). In this multi-center randomized controlled trial "PARADISE study" (NCT05671315), CHB patients with intermediate to high risk of HCC after more than 24-week NAs pretreatment were recruited, randomized to two groups at a ratio of 1:2 and followed up for 240 weeks. NAs group maintained NAs monotherapy, while IFN + NAs group received IFN add-on NAs therapy for 48 weeks, then switched to NAs monotherapy. Totally, 196 patients were included in interim analysis (NAs group 68, IFN + NAs group 128). The 96-week cumulative HCC incidence was lower in IFN + NAs group than NAs group (0% vs. 4.5%, p < 0.05). Compared with NAs group, IFN + NAs group had significantly higher rates of HBsAg loss at week 48 and 96 (22.7% vs. 0%; 16.7% vs. 0%, both p < 0.05). A new scoring system was established to predict HBsAg decline >2log10 IU/ml, HBsAg <10 IU/ml or HBsAg loss at the end of 48-week IFN treatment. The area under ROC curve was 0.914, 0.922 or 0.905 in the original cohort (n = 128) and 0.896, 0.896 or 0.864 in the external validation cohort (n = 162) for the aforementioned three outcomes, respectively. IFN add-on NAs therapy may suggest the dual benefits of reducing HCC development and facilitating HBsAg loss among NA-treated CHB patients with intermediate to high risk of HCC. The new scoring system helps to make the most of IFN treatment for a higher cost-effectiveness in healthcare.

Valacyclovir or valganciclovir for cytomegalovirus prophylaxis: A randomized controlled trial in adult and pediatric kidney transplant recipients.

BACKGROUND: Valganciclovir (valG), a cytomegalovirus (CMV) prophylactic agent, has dose-limiting side effects. The tolerability and effectiveness of valacyclovir (valA) as CMV prophylaxis is unknown. METHODS: We conducted a randomized, open-label, single-center trial of valA versus valG for all posttransplant CMV prophylaxis in adult and pediatric kidney recipients. Participants were randomly assigned to receive valA or valG. Primary endpoints were the incidence of CMV viremia and side-effect related drug reduction with secondary assessment of incidence of EBV viremia. RESULTS: Of the 137 sequential kidney transplant recipients enrolled, 26 % were positive and negative for CMV antibody in donor and recipient respectively. The incidence of CMV viremia (4 of 71 [6 %]; 8 of 67 [12 %] P = 0.23), time to viremia (P = 0.16) and area under CMV viral load time curve (P = 0.19) were not significantly different. ValG participants were significantly more likely to require side-effect related dose reduction (15/71 [21 %] versus 1/66 [2 %] P = 0.0003). Leukopenia was the most common reason for valG dose reduction and granulocyte-colony stimulating factor was utilized for leukopenia recovery more frequently (25 % in valG vs 5 % in valA: P = 0.0007). Incidence of EBV viremia was not significantly different. CONCLUSIONS: ValA has significantly less dose-limiting side effects than valG. In our study population, a significant increase in CMV viremia was not observed, in adults and children after kidney transplant, compared to valG. TRIAL REGISTRATION NUMBER: NCT01329185.

Nanostructured lipid carriers loaded with essential oils: a strategy against SARS-CoV-2.

This work aimed to investigate the effectiveness of Lippia sidoides and Syzygium aromaticum essential oils (EOs) encapsulated in nanostructured lipid carriers (NLCs) as SARS-CoV-2 inhibitors through virucidal activity assessment. We developed anionic and cationic NLCs loaded with the EOs and assessed their physicochemical properties and SARS-CoV-2 virucidal activity, focusing on the effects of EO type and the NLCs composition. The NLCs exhibited particle sizes of 141.30 to 160.53 nm for anionic and 109.30 to 138.60 nm for cationic types, with PDIs between 0.16 and 0.25. High zeta potentials (>29.0 in modulus) indicated stable formulations. The NLCs effectively encapsulated the EOs, achieving encapsulation efficiencies between 84.6 to 100% w/w of marker compound. The EOs-loaded NLCs reduced the SARS-CoV-2 virion count, exceeding 2 logs over the control. NLCs loaded with Lippia sidoides and Syzygium aromaticum EOs represent an innovative strategy for combating SARS-CoV-2.

Throat spray formulated with virucidal pharmaceutical excipients as an effective early prophylactic or treatment strategy against pharyngitis post-exposure to SARS-CoV-2.

Our study aimed to develop a virucidal throat spray using bioactive compounds and excipients, focusing on the preparation of Curcumin (CUR) in a self-nano emulsifying drug delivery system (SNEDDS). Two molecular docking studies against SARS-CoV-2 targets guided the selection of proper oil, surfactant, co-surfactant, and natural bioactive that would maximize the antiviral activity of the throat spray. Two self-nanoemulsifying formulas that were diluted with different vehicles to prepare eight CUR-loaded SNESNS (self-nanoemulsifying self-nanosuspension) formulas. In vitro characterization studies and in vitro anti-SARS-CoV-2 effect revealed that the optimal formula, consisted of 20 % Anise oil, 70 % Tween 80, 10 % PEG 400, and 0.1 %w/w CUR, diluted with DEAE-Dx. Preclinical toxicity tests on male rats confirmed the safety of a mild throat spray dose (5 µg/mL CUR). In a rat model of acute pharyngitis induced by ammonia, post-treatment with the optimal formula of CUR loaded SNESNS for one week significantly reduced elevated proinflammatory markers (TNF-α, IL6, MCP1, and IL8). In conclusion, our CUR-loaded SNESNS formula, at 5 µg/mL concentration, shows promising effect as a prophylactic throat spray against SARS-CoV-2 and as a treatment for pharyngitis.

Phlorizin Limits Bovine Viral Diarrhea Virus Infection in Mice via Regulating Gut Microbiota Composition.

Phlorizin (PHZ) is one of the main pharmacologically active ingredients in Lithocarpus polystachyus. We have previously shown that PHZ inhibits the replication of bovine viral diarrhea virus (BVDV), but the exact antiviral mechanism, especially in vivo, is still unknown. Here, we further confirm that PHZ has good protective effects in BVDV-infected mice. We analyzed BVDV-induced CD3+, CD4+, and CD8+ T cells among peripheral blood lymphocytes and found that PHZ significantly restored their percentage. Metagenomic analyses revealed that PHZ markedly improved the richness and diversity of intestinal microbiota and increased the abundance of potentially health-related microbes (families Lachnosipiraceae, Ruminococcaceae, and Oscillospiraceae). Specifically, the relative abundance of short chain fatty acid (SCFA)-producing bacteria, including Lachnospiraceae_UCG-006, unclassified_f_Ruminococcaceae, Oscillibacter, Intestinimonas, Blautia, and Lachnoclostridium increased significantly after PHZ treatment. Interestingly, BVDV-infected mice that received fecal microbiota from PHZ-treated mice (PHZ-FMT) had a significantly lower viral load in the duodenum and jejunum than untreated mice. Pathological lesions of duodenum and jejunum were also greatly reduced in the PHZ-FMT group, confirming a significant antiviral effect. These findings show that gut microbiota play an important role in PHZ's antiviral activity and suggest that their targeted intervention might be a promising endogenous strategy to prevent and control BVDV.