Population Pharmacokinetics of Nirsevimab in Preterm and Term Infants

Nirsevimab, a monoclonal antibody with an extended half-life, is approved for the prevention of respiratory syncytial virus (RSV) disease in all infants in Canada, the EU, Great Britain, and the USA. A population pharmacokinetics (PK) model was built to describe the PK of nirsevimab in preterm and term infants, and to evaluate the influence of covariates, including body weight and age, in infants. Nirsevimab PK was characterized by a 2-compartment model with first-order clearance (CL) and first-order absorption following intramuscular (IM) administration. The typical CL in a 5 kg infant was 3.4 mL/day. Body weight and postmenstrual age were the primary covariates on CL, with minor effects for race, second RSV season, and antidrug antibody status (deemed not clinically relevant). Congenital heart disease (CHD) and chronic lung disease (CLD) did not significantly impact nirsevimab PK. The final population PK model, based on 8987 PK observations from 2683 participants across 5 clinical trials, successfully predicted PK in an additional cohort of 967 healthy infants. Weight-banded dosing (50 mg in infants <5 kg; 100 mg in infants ≥5 kg) was predicted to be appropriate for infants ≥1 kg in their first RSV season. Together, these data support weight-banded dosing of nirsevimab in all infants in their first RSV season, including in healthy infants, infants with CHD or CLD, and in infants born prematurely.

Physiologically Based Pharmacokinetic Modeling for Maribavir to Inform Dosing in Drug-Drug Interaction Scenarios with CYP3A4 Inducers and Inhibitors

Maribavir, an orally available antiviral agent, has been approved in multiple countries for the treatment of patients with refractory post-transplant cytomegalovirus (CMV) infection and/or disease. Maribavir is primarily metabolized by CYP3A4; coadministration with CYP3A4 inducers and inhibitors may significantly alter maribavir exposure, thereby affecting its efficacy and safety. The effect of CYP3A4 inducers and inhibitors on maribavir exposure was evaluated based on a drug-drug interaction (DDI) study and physiologically-based pharmacokinetic (PBPK) modeling. The effect of rifampin (a strong inducer of CYP3A4 and moderate inducer of CYP1A2), administered at a 600 mg dose once daily, on maribavir pharmacokinetics was assessed in a clinical phase 1 DDI study in healthy participants. A full PBPK model for maribavir was developed and verified using in vitro and clinical pharmacokinetic data from phase 1 studies. The verified PBPK model was then used to simulate maribavir DDI interactions with various CYP3A4 inducers and inhibitors. The DDI study results showed that coadministration with rifampin decreased the maribavir maximum plasma concentration (Cmax), area under the plasma concentration-time curve (AUC), and trough concentration (Ctrough) by 39%, 60%, and 82%, respectively. Based on the results from the clinical DDI study, the coadministration of maribavir with rifampin is not recommended. The PBPK model did not predict a clinically significant effect of CYP3A4 inhibitors on maribavir exposure; however, it predicted that strong or moderate CYP3A4 inducers, including carbamazepine, efavirenz, phenobarbital, and phenytoin, may reduce maribavir exposure to a clinically significant extent, and may prompt the consideration of a maribavir dosing increase, in accordance with local approved labels and/or regulations.

Oral administration of obeldesivir protects nonhuman primates against Sudan ebolavirus

Obeldesivir (ODV, GS-5245) is an orally administered prodrug of the parent nucleoside of remdesivir (RDV) and is presently in phase 3 trials for COVID-19 treatment. In this work, we show that ODV and its circulating parent nucleoside metabolite, GS-441524, have similar in vitro antiviral activity against filoviruses, including Marburg virus, Ebola virus, and Sudan virus (SUDV). We also report that once-daily oral ODV treatment of cynomolgus monkeys for 10 days beginning 24 hours after SUDV exposure confers 100% protection against lethal infection. Transcriptomics data show that ODV treatment delayed the onset of inflammation and correlated with antigen presentation and lymphocyte activation. Our results offer promise for the further development of ODV to control outbreaks of filovirus disease more rapidly.

An oral antiviral for Ebola disease

For those exposed to filovirus, such as Sudan virus and Ebola virus, a new study offers hope.

Oral Simnotrelvir for Adult Patients with Mild-to-Moderate Covid-19

BACKGROUND

Simnotrelvir is an oral 3-chymotrypsin-like protease inhibitor that has been found to have in vitro activity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and potential efficacy in a phase 1B trial.

METHODS

In this phase 2-3, double-blind, randomized, placebo-controlled trial, we assigned patients who had mild-to-moderate coronavirus disease 2019 (Covid-19) and onset of symptoms within the past 3 days in a 1:1 ratio to receive 750 mg of simnotrelvir plus 100 mg of ritonavir or placebo twice daily for 5 days. The primary efficacy end point was the time to sustained resolution of symptoms, defined as the absence of 11 Covid-19-related symptoms for 2 consecutive days. Safety and changes in viral load were also assessed.

RESULTS

A total of 1208 patients were enrolled at 35 sites in China; 603 were assigned to receive simnotrelvir and 605 to receive placebo. Among patients in the modified intention-to-treat population who received the first dose of trial drug or placebo within 72 hours after symptom onset, the time to sustained resolution of Covid-19 symptoms was significantly shorter in the simnotrelvir group than in the placebo group (180.1 hours [95% confidence interval {CI}, 162.1 to 201.6] vs. 216.0 hours [95% CI, 203.4 to 228.1]; median difference, -35.8 hours [95% CI, -60.1 to -12.4]; P = 0.006 by Peto-Prentice test). On day 5, the decrease in viral load from baseline was greater in the simnotrelvir group than in the placebo group (mean difference [±SE], -1.51±0.14 log10 copies per milliliter; 95% CI, -1.79 to -1.24). The incidence of adverse events during treatment was higher in the simnotrelvir group than in the placebo group (29.0% vs. 21.6%). Most adverse events were mild or moderate.

CONCLUSIONS

Early administration of simnotrelvir plus ritonavir shortened the time to the resolution of symptoms among adult patients with Covid-19, without evident safety concerns. (Funded by Jiangsu Simcere Pharmaceutical; ClinicalTrials.gov number, NCT05506176.).

Safety, tolerability, and pharmacokinetics of half-life extended SARS-CoV-2-neutralizing monoclonal antibodies AZD7442 (tixagevimab/cilgavimab) in healthy Japanese adults

INTRODUCTION

The aim of this study was to evaluate the safety, tolerability, pharmacokinetics, and pharmacodynamics of AZD7442 (tixagevimab/cilgavimab) in healthy Japanese adults.

METHODS

In this randomized, double-blind, placebo-controlled, phase 1 study, AZD7442 was administered intramuscularly (300 or 600 mg) or intravenously (300 or 1000 mg) to healthy Japanese adults. Primary endpoints were safety, tolerability, and pharmacokinetics. Anti-drug antibodies and neutralizing antibody activities were secondary endpoints.

RESULTS

A total of 40 participants were randomized to receive AZD7442 (n = 30) or placebo (n = 10). Adverse events (AEs) occurred in 12 (40%) and 3 (30%) participants, respectively; there were no deaths, serious AEs, or AEs leading to study withdrawal. Tixagevimab and cilgavimab had mean half-lives of 82.1-95.9 and 77.9-92.0 days, respectively, which were generally similar regardless of administration route. SARS-CoV-2-neutralizing antibody titers were >4-fold higher than baseline levels from Day 8 to Day 211 in participants receiving AZD7442.

CONCLUSIONS

AZD7442 was well tolerated in healthy Japanese adults, with predictable pharmacokinetics and an extended half-life, consistent with previous studies.

CLINICALTRIALS

gov, NCT04896541.

Virological safety of the UK blood supply in the era of individual risk assessments and HIV PrEP

A more individualised donor selection policy was implemented in the UK in 2021, which replaced the previous 3-month deferral for men who have sex with men (MSM). Other blood services have a variety of policies in place to ensure the virological safety of blood components, ranging from an indefinite ban on MSM, to a defined period of exclusion, or to an individualised risk assessment that is not based on gender or sexual orientation. Justification of these policies should be based on scientific evidence including assessment of lengths of virological window periods, infectious disease epidemiology within donor populations and donation screening assay sensitivities. Developments in molecular technology and assays which can detect both antibodies and antigens in the very early stages of infection have significantly reduced the risk in most developed countries. However, the increasing usage of pre-exposure prophylaxis (PrEP) to prevent acquisition of HIV infection after possible high-risk sexual contact within the UK blood donor population has been recently noted. It has brought with it new diagnostic challenges within blood screening, notably possible non-detection of HIV RNA and serological markers following PrEP use despite potential infectivity. The use of other testing strategies such as detection of HIV DNA and screening for non-declared PrEP usage should be investigated further.

Monoclonal Antibody and Oral Antiviral Treatment of SARS-CoV-2 Infection in US Nursing Homes

This study examines the use of COVID-19 antiviral treatments in US nursing homes and the facility characteristics associated with use of oral antivirals and monoclonal antibodies.

Long-Term Impact of Direct-Acting Antivirals on Liver Fibrosis and Survival in HCV-Infected Liver Transplant Recipients

(1) Background: Little is known about the long-term impact of sustained virological response (SVR) on fibrosis progression and patient survival in liver transplantation (LT) recipients treated with direct-acting antivirals (DAAs). We investigated liver fibrosis evolution and patient survival in hepatitis C virus (HCV)-infected patients receiving DAAs after LT. (2) Methods: All consecutive HCV-infected patients treated with DAAs after LT between May 2014 and January 2019 were considered. The clinical and virological features were registered at the baseline and during the follow-up. The liver fibrosis was assessed by liver biopsy and/or transient elastography (TE) at the baseline and at least 1 year after the end of treatment (EoT). (3) Results: A total of 136 patients were included. The SVR12 was 78% after the first treatment and 96% after retreatment. After the SVR12, biochemical tests improved at the EoT and remained stable throughout the 3-year follow-up. Liver fibrosis improved after the SVR12 (p < 0.001); nearly half of the patients with advanced liver fibrosis experienced an improvement of an F ≤ 2. The factors associated with lower survival in SVR12 patients were the baseline platelet count (p = 0.04) and creatinine level (p = 0.04). (4) Conclusions: The long-term follow-up data demonstrated that SVR12 was associated with an improvement in hepatic function, liver fibrosis, and post-LT survival, regardless of the baseline liver fibrosis. The presence of portal hypertension before the DAAs has an impact on patient survival, even after SVR12.

A Phase 3, Randomized Trial of Bulevirtide in Chronic Hepatitis D

BACKGROUND

Coinfection with hepatitis D virus (HDV) accelerates the progression of liver disease associated with chronic hepatitis B. Bulevirtide inhibits the entry of HDV into hepatocytes.

METHODS

In this ongoing phase 3 trial, patients with chronic hepatitis D, with or without compensated cirrhosis, were randomly assigned, in a 1:1:1 ratio, to receive bulevirtide subcutaneously at 2 mg per day (2-mg group) or 10 mg per day (10-mg group) for 144 weeks or to receive no treatment for 48 weeks followed by bulevirtide subcutaneously at 10 mg per day for 96 weeks (control group). Patients will complete 96 weeks of additional follow-up after the end of treatment. The primary end point was a combined response at week 48 of an undetectable HDV RNA level, or a level that decreased by at least 2 log10 IU per milliliter from baseline, and normalization of the alanine aminotransferase (ALT) level. The key secondary end point was an undetectable HDV RNA level at week 48, in a comparison between the 2-mg group and the 10-mg group.

RESULTS

A total of 49 patients were assigned to the 2-mg group, 50 to the 10-mg group, and 51 to the control group. A primary end-point response occurred in 45% of patients in the 2-mg group, 48% in the 10-mg group, and 2% in the control group (P<0.001 for the comparison of each dose group with the control group). The HDV RNA level at week 48 was undetectable in 12% of patients in the 2-mg group and in 20% in the 10-mg group (P = 0.41). The ALT level normalized in 12% of patients in the control group, 51% in the 2-mg group (difference from control, 39 percentage points [95% confidence interval {CI}, 20 to 56]), and 56% in the 10-mg group (difference from control, 44 percentage points [95% CI, 26 to 60]). Loss of hepatitis B virus surface antigen (HBsAg) or an HBsAg level that decreased by at least 1 log10 IU per milliliter did not occur in the bulevirtide groups by week 48. Headache, pruritus, fatigue, eosinophilia, injection-site reactions, upper abdominal pain, arthralgia, and asthenia were more common in the 2-mg and 10-mg groups combined than in the control group. No treatment-related serious adverse events occurred. Dose-dependent increases in bile acid levels were noted in the 2-mg and 10-mg groups.

CONCLUSIONS

After 48 weeks of bulevirtide treatment, HDV RNA and ALT levels were reduced in patients with chronic hepatitis D. (Funded by Gilead Sciences; MYR 301 ClinicalTrials.gov number, NCT03852719.).

Letermovir vs Valganciclovir for Prophylaxis of Cytomegalovirus in High-Risk Kidney Transplant Recipients: A Randomized Clinical Trial

Importance

Valganciclovir for 200 days is standard care for cytomegalovirus (CMV) prophylaxis in high-risk CMV-seronegative kidney transplant recipients who receive an organ from a CMV-seropositive donor, but its use is limited by myelosuppression.

Objective

To compare the efficacy and safety of letermovir with valganciclovir for prevention of CMV disease in CMV-seronegative kidney transplant recipients who receive an organ from a CMV-seropositive donor.

Design, Setting, and Participants

Randomized, double-masked, double-dummy, noninferiority, phase 3 trial in adult CMV-seronegative kidney transplant recipients who received an organ from a CMV-seropositive donor at 94 participating sites between May 2018 and April 2021 (final follow-up in April 2022).

Interventions

Participants were randomized in a 1:1 ratio (stratified by receipt of lymphocyte-depleting induction immunosuppression) to receive letermovir, 480 mg, orally daily (with acyclovir) or valganciclovir, 900 mg, orally daily (adjusted for kidney function) for up to 200 days after transplant, with matching placebos.

Main Outcomes and Measures

The primary outcome was CMV disease, confirmed by an independent masked adjudication committee, through posttransplant week 52 (prespecified noninferiority margin, 10%). CMV disease through week 28 and time to onset of CMV disease through week 52 were secondary outcomes. Exploratory outcomes included quantifiable CMV DNAemia and resistance. The rate of leukopenia or neutropenia through week 28 was a prespecified safety outcome.

Results

Among 601 participants randomized, 589 received at least 1 dose of the study drug (mean age, 49.6 years; 422 [71.6%] men). Letermovir (n = 289) was noninferior to valganciclovir (n = 297) for prevention of CMV disease through week 52 (10.4% vs 11.8% of participants with committee-confirmed CMV disease; stratum-adjusted difference -1.4% [95% CI, -6.5% to 3.8%]). No participants who received letermovir vs 5 participants (1.7%) who received valganciclovir developed CMV disease through week 28. Time to onset of CMV disease was comparable between the groups (hazard ratio, 0.90 [95% CI, 0.56-1.47]). Quantifiable CMV DNAemia was detected in 2.1% of participants in the letermovir group vs 8.8% in the valganciclovir group by week 28. Of participants evaluated for suspected CMV disease or CMV DNAemia, none (0/52) who received letermovir and 12.1% (8/66) who received valganciclovir had resistance-associated substitutions. The rate of leukopenia or neutropenia through week 28 was lower with letermovir vs valganciclovir (26% vs 64%; difference, -37.9% [95% CI, -45.1% to -30.3%]; P < .001). Fewer participants in the letermovir group than the valganciclovir group discontinued prophylaxis due to adverse events (4.1% vs 13.5%) or drug-related adverse events (2.7% vs 8.8%).

Conclusion and Relevance

Among adult CMV-seronegative kidney transplant recipients who received an organ from a CMV-seropositive donor, letermovir was noninferior to valganciclovir for prophylaxis of CMV disease over 52 weeks, with lower rates of leukopenia or neutropenia, supporting its use for this indication.

Trial Registration

ClinicalTrials.gov Identifier: NCT03443869; EudraCT: 2017-001055-30.

Nirmatrelvir treatment of SARS-CoV-2-infected mice blunts antiviral adaptive immune responses

Alongside vaccines, antiviral drugs are becoming an integral part of our response to the SARS-CoV-2 pandemic. Nirmatrelvir-an orally available inhibitor of the 3-chymotrypsin-like cysteine protease-has been shown to reduce the risk of progression to severe COVID-19. However, the impact of nirmatrelvir treatment on the development of SARS-CoV-2-specific adaptive immune responses is unknown. Here, by using mouse models of SARS-CoV-2 infection, we show that nirmatrelvir administration blunts the development of SARS-CoV-2-specific antibody and T cell responses. Accordingly, upon secondary challenge, nirmatrelvir-treated mice recruited significantly fewer memory T and B cells to the infected lungs and mediastinal lymph nodes, respectively. Together, the data highlight a potential negative impact of nirmatrelvir treatment with important implications for clinical management and might help explain the virological and/or symptomatic relapse after treatment completion reported in some individuals.

High-dose valacyclovir to prevent congenital cytomegalovirus transmission in pregnancy: is it possible to reduce major side effects?

Linked article: This Correspondence comments on D'Antonio et al. Click here to view the article.

Early Treatment with Pegylated Interferon Lambda for Covid-19

BACKGROUND

The efficacy of a single dose of pegylated interferon lambda in preventing clinical events among outpatients with acute symptomatic coronavirus disease 2019 (Covid-19) is unclear.

METHODS

We conducted a randomized, controlled, adaptive platform trial involving predominantly vaccinated adults with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in Brazil and Canada. Outpatients who presented with an acute clinical condition consistent with Covid-19 within 7 days after the onset of symptoms received either pegylated interferon lambda (single subcutaneous injection, 180 μg) or placebo (single injection or oral). The primary composite outcome was hospitalization (or transfer to a tertiary hospital) or an emergency department visit (observation for >6 hours) due to Covid-19 within 28 days after randomization.

RESULTS

A total of 933 patients were assigned to receive pegylated interferon lambda (2 were subsequently excluded owing to protocol deviations) and 1018 were assigned to receive placebo. Overall, 83% of the patients had been vaccinated, and during the trial, multiple SARS-CoV-2 variants had emerged. A total of 25 of 931 patients (2.7%) in the interferon group had a primary-outcome event, as compared with 57 of 1018 (5.6%) in the placebo group, a difference of 51% (relative risk, 0.49; 95% Bayesian credible interval, 0.30 to 0.76; posterior probability of superiority to placebo, >99.9%). Results were generally consistent in analyses of secondary outcomes, including time to hospitalization for Covid-19 (hazard ratio, 0.57; 95% Bayesian credible interval, 0.33 to 0.95) and Covid-19-related hospitalization or death (hazard ratio, 0.59; 95% Bayesian credible interval, 0.35 to 0.97). The effects were consistent across dominant variants and independent of vaccination status. Among patients with a high viral load at baseline, those who received pegylated interferon lambda had lower viral loads by day 7 than those who received placebo. The incidence of adverse events was similar in the two groups.

CONCLUSIONS

Among predominantly vaccinated outpatients with Covid-19, the incidence of hospitalization or an emergency department visit (observation for >6 hours) was significantly lower among those who received a single dose of pegylated interferon lambda than among those who received placebo. (Funded by FastGrants and others; TOGETHER ClinicalTrials.gov number, NCT04727424.).

VV116 versus Nirmatrelvir-Ritonavir for Oral Treatment of Covid-19

BACKGROUND

Nirmatrelvir-ritonavir has been authorized for emergency use by many countries for the treatment of coronavirus disease 2019 (Covid-19). However, the supply falls short of the global demand, which creates a need for more options. VV116 is an oral antiviral agent with potent activity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

METHODS

We conducted a phase 3, noninferiority, observer-blinded, randomized trial during the outbreak caused by the B.1.1.529 (omicron) variant of SARS-CoV-2. Symptomatic adults with mild-to-moderate Covid-19 with a high risk of progression were assigned to receive a 5-day course of either VV116 or nirmatrelvir-ritonavir. The primary end point was the time to sustained clinical recovery through day 28. Sustained clinical recovery was defined as the alleviation of all Covid-19-related target symptoms to a total score of 0 or 1 for the sum of each symptom (on a scale from 0 to 3, with higher scores indicating greater severity; total scores on the 11-item scale range from 0 to 33) for 2 consecutive days. A lower boundary of the two-sided 95% confidence interval for the hazard ratio of more than 0.8 was considered to indicate noninferiority (with a hazard ratio of >1 indicating a shorter time to sustained clinical recovery with VV116 than with nirmatrelvir-ritonavir).

RESULTS

A total of 822 participants underwent randomization, and 771 received VV116 (384 participants) or nirmatrelvir-ritonavir (387 participants). The noninferiority of VV116 to nirmatrelvir-ritonavir with respect to the time to sustained clinical recovery was established in the primary analysis (hazard ratio, 1.17; 95% confidence interval [CI], 1.01 to 1.35) and was maintained in the final analysis (median, 4 days with VV116 and 5 days with nirmatrelvir-ritonavir; hazard ratio, 1.17; 95% CI, 1.02 to 1.36). In the final analysis, the time to sustained symptom resolution (score of 0 for each of the 11 Covid-19-related target symptoms for 2 consecutive days) and to a first negative SARS-CoV-2 test did not differ substantially between the two groups. No participants in either group had died or had had progression to severe Covid-19 by day 28. The incidence of adverse events was lower in the VV116 group than in the nirmatrelvir-ritonavir group (67.4% vs. 77.3%).

CONCLUSIONS

Among adults with mild-to-moderate Covid-19 who were at risk for progression, VV116 was noninferior to nirmatrelvir-ritonavir with respect to the time to sustained clinical recovery, with fewer safety concerns. (Funded by Vigonvita Life Sciences and others; ClinicalTrials.gov number, NCT05341609; Chinese Clinical Trial Registry number, ChiCTR2200057856.).

Integrating network pharmacology and experimental validation to decipher the mechanism of the Chinese herbal prescription JieZe-1 in protecting against HSV-2 infection

CONTEXT

The Chinese herbal prescription JieZe-1 (JZ-1) is effective against HSV-2 (Herpes simplex virus type 2) infection. However, its mechanism remains unclear.

OBJECTIVE

To explore the mechanism of JZ-1 in protecting against HSV-2 infection.

MATERIALS AND METHODS

Using the methods of network pharmacology, the hub components and targets were screened and functionally enriched. We established a genital herpes (GH) mouse model and observe the disease characteristics. Then, the GH mice in different groups (10 per/group) were treated with 20 μL JZ-1 gel (2.5, 1.5, and 0.5 g/mL), acyclovir gel (0.03 g/mL), or plain carbomer gel twice a day. The symptom score, vulvar histomorphology, and virus load were measured. The critical proteins of caspase-1-dependent pyroptosis were analysed by microscopy, co-immunoprecipitation, western blotting, and ELISA. Molecular docking was also performed.

RESULTS

Network pharmacology analysis identified 388 JZ-1 targets related to HSV-2 infection, with 36 hub targets and 21 hub components screened. The TCID₅₀ of HSV-2 was 1 × 10^-7/0.1 mL. JZ-1 gel (2.5 g/mL) can effectively reduce the symptom score (81.23%), viral load (98.42%) and histopathological changes, and significantly inhibit the proteins expression of caspase-1-dependent pyroptosis in GH mice (p< 0.05). The molecular docking test showed a good binding potency between 11 components and caspase-1 or interleukin (IL)-1β.

DISCUSSION AND CONCLUSIONS

The present study demonstrated that JZ-1 protected mice from HSV-2 infection and inhibit the caspase-1-dependent pyroptosis in GH mice. It is of significance for the second development of JZ-1 and the exploration of new drugs.

The vital role of animal, marine, and microbial natural products against COVID-19

CONTEXT

Since the outbreak of SARS-CoV-2, researchers have been working on finding ways to prevent viral entry and pathogenesis. Drug development from naturally-sourced pharmacological constituents may be a fruitful approach to COVID-19 therapy.

OBJECTIVE

Most of the published literature has focussed on medicinal plants, while less attention has been given to biodiverse sources such as animal, marine, and microbial products. This review focuses on highlighting natural products and their derivatives that have been evaluated for antiviral, anti-inflammatory, and immunomodulatory properties.

METHODS

We searched electronic databases such as PubMed, Scopus, Science Direct and Springer Link to gather raw data from publications up to March 2021, using terms such as 'natural products', marine, micro-organism, and animal, COVID-19. We extracted a number of documented clinical trials of products that were tested in silico, in vitro, and in vivo which paid specific attention to chemical profiles and mechanisms of action.

RESULTS

Various classes of flavonoids, 2 polyphenols, peptides and tannins were found, which exhibit inhibitory properties against viral and host proteins, including 3CLpro, PLpro, S, hACE2, and NF-κB, many of which are in different phases of clinical trials.

DISCUSSION AND CONCLUSIONS

The synergistic effects of logical combinations with different mechanisms of action emphasizes their value in COVID19 management, such as iota carrageenan nasal spray, ermectin oral drops, omega-3 supplementation, and a quadruple treatment of zinc, quercetin, bromelain, and vitamin C. Though in vivo efficacy of these compounds has yet to be established, these bioproducts are potentially useful in counteracting the effects of SARS-CoV-2.

Intramuscular AZD7442 (Tixagevimab-Cilgavimab) for Prevention of Covid-19

BACKGROUND

The monoclonal-antibody combination AZD7442 is composed of tixagevimab and cilgavimab, two neutralizing antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that have an extended half-life and have been shown to have prophylactic and therapeutic effects in animal models. Pharmacokinetic data in humans indicate that AZD7442 has an extended half-life of approximately 90 days.

METHODS

In an ongoing phase 3 trial, we enrolled adults (≥18 years of age) who had an increased risk of an inadequate response to vaccination against coronavirus disease 2019 (Covid-19), an increased risk of exposure to SARS-CoV-2, or both. Participants were randomly assigned in a 2:1 ratio to receive a single dose (two consecutive intramuscular injections, one containing tixagevimab and the other containing cilgavimab) of either 300 mg of AZD7442 or saline placebo, and they were followed for up to 183 days in the primary analysis. The primary safety end point was the incidence of adverse events after a single dose of AZD7442. The primary efficacy end point was symptomatic Covid-19 (SARS-CoV-2 infection confirmed by means of reverse-transcriptase-polymerase-chain-reaction assay) occurring after administration of AZD7442 or placebo and on or before day 183.

RESULTS

A total of 5197 participants underwent randomization and received one dose of AZD7442 or placebo (3460 in the AZD7442 group and 1737 in the placebo group). The primary analysis was conducted after 30% of the participants had become aware of their randomized assignment. In total, 1221 of 3461 participants (35.3%) in the AZD7442 group and 593 of 1736 participants (34.2%) in the placebo group reported having at least one adverse event, most of which were mild or moderate in severity. Symptomatic Covid-19 occurred in 8 of 3441 participants (0.2%) in the AZD7442 group and in 17 of 1731 participants (1.0%) in the placebo group (relative risk reduction, 76.7%; 95% confidence interval [CI], 46.0 to 90.0; P<0.001); extended follow-up at a median of 6 months showed a relative risk reduction of 82.8% (95% CI, 65.8 to 91.4). Five cases of severe or critical Covid-19 and two Covid-19-related deaths occurred, all in the placebo group.

CONCLUSIONS

A single dose of AZD7442 had efficacy for the prevention of Covid-19, without evident safety concerns. (Funded by AstraZeneca and the U.S. government; PROVENT ClinicalTrials.gov number, NCT04625725.).

Oral Nirmatrelvir for High-Risk, Nonhospitalized Adults with Covid-19

BACKGROUND

Nirmatrelvir is an orally administered severe acute respiratory syndrome coronavirus 2 main protease (Mpro) inhibitor with potent pan-human-coronavirus activity in vitro.

METHODS

We conducted a phase 2-3 double-blind, randomized, controlled trial in which symptomatic, unvaccinated, nonhospitalized adults at high risk for progression to severe coronavirus disease 2019 (Covid-19) were assigned in a 1:1 ratio to receive either 300 mg of nirmatrelvir plus 100 mg of ritonavir (a pharmacokinetic enhancer) or placebo every 12 hours for 5 days. Covid-19-related hospitalization or death from any cause through day 28, viral load, and safety were evaluated.

RESULTS

A total of 2246 patients underwent randomization; 1120 patients received nirmatrelvir plus ritonavir (nirmatrelvir group) and 1126 received placebo (placebo group). In the planned interim analysis of patients treated within 3 days after symptom onset (modified intention-to treat population, comprising 774 of the 1361 patients in the full analysis population), the incidence of Covid-19-related hospitalization or death by day 28 was lower in the nirmatrelvir group than in the placebo group by 6.32 percentage points (95% confidence interval [CI], -9.04 to -3.59; P<0.001; relative risk reduction, 89.1%); the incidence was 0.77% (3 of 389 patients) in the nirmatrelvir group, with 0 deaths, as compared with 7.01% (27 of 385 patients) in the placebo group, with 7 deaths. Efficacy was maintained in the final analysis involving the 1379 patients in the modified intention-to-treat population, with a difference of -5.81 percentage points (95% CI, -7.78 to -3.84; P<0.001; relative risk reduction, 88.9%). All 13 deaths occurred in the placebo group. The viral load was lower with nirmatrelvir plus ritonavir than with placebo at day 5 of treatment, with an adjusted mean difference of -0.868 log10 copies per milliliter when treatment was initiated within 3 days after the onset of symptoms. The incidence of adverse events that emerged during the treatment period was similar in the two groups (any adverse event, 22.6% with nirmatrelvir plus ritonavir vs. 23.9% with placebo; serious adverse events, 1.6% vs. 6.6%; and adverse events leading to discontinuation of the drugs or placebo, 2.1% vs. 4.2%). Dysgeusia (5.6% vs. 0.3%) and diarrhea (3.1% vs. 1.6%) occurred more frequently with nirmatrelvir plus ritonavir than with placebo.

CONCLUSIONS

Treatment of symptomatic Covid-19 with nirmatrelvir plus ritonavir resulted in a risk of progression to severe Covid-19 that was 89% lower than the risk with placebo, without evident safety concerns. (Supported by Pfizer; ClinicalTrials.gov number, NCT04960202.).

Effect of Sotrovimab on Hospitalization or Death Among High-risk Patients With Mild to Moderate COVID-19: A Randomized Clinical Trial

IMPORTANCE

Older patients and those with comorbidities who are infected with SARS-CoV-2 may be at increased risk of hospitalization and death. Sotrovimab is a neutralizing antibody for the treatment of high-risk patients to prevent COVID-19 progression.

OBJECTIVE

To evaluate the efficacy and adverse events of sotrovimab in preventing progression of mild to moderate COVID-19 to severe disease.

DESIGN, SETTING, AND PARTICIPANTS

Randomized clinical trial including 1057 nonhospitalized patients with symptomatic, mild to moderate COVID-19 and at least 1 risk factor for progression conducted at 57 sites in Brazil, Canada, Peru, Spain, and the US from August 27, 2020, through March 11, 2021; follow-up data were collected through April 8, 2021.

INTERVENTIONS

Patients were randomized (1:1) to an intravenous infusion with 500 mg of sotrovimab (n = 528) or placebo (n = 529).

MAIN OUTCOMES AND MEASURES

The primary outcome was the proportion of patients with COVID-19 progression through day 29 (all-cause hospitalization lasting >24 hours for acute illness management or death); 5 secondary outcomes were tested in hierarchal order, including a composite of all-cause emergency department (ED) visit, hospitalization of any duration for acute illness management, or death through day 29 and progression to severe or critical respiratory COVID-19 requiring supplemental oxygen or mechanical ventilation.

RESULTS

Enrollment was stopped early for efficacy at the prespecified interim analysis. Among 1057 patients randomized (median age, 53 years [IQR, 42-62], 20% were ≥65 years of age, and 65% Latinx), the median duration of follow-up was 103 days for sotrovimab and 102 days for placebo. All-cause hospitalization lasting longer than 24 hours or death was significantly reduced with sotrovimab (6/528 [1%]) vs placebo (30/529 [6%]) (adjusted relative risk [RR], 0.21 [95% CI, 0.09 to 0.50]; absolute difference, -4.53% [95% CI, -6.70% to -2.37%]; P < .001). Four of the 5 secondary outcomes were statistically significant in favor of sotrovimab, including reduced ED visit, hospitalization, or death (13/528 [2%] for sotrovimab vs 39/529 [7%] for placebo; adjusted RR, 0.34 [95% CI, 0.19 to 0.63]; absolute difference, -4.91% [95% CI, -7.50% to -2.32%]; P < .001) and progression to severe or critical respiratory COVID-19 (7/528 [1%] for sotrovimab vs 28/529 [5%] for placebo; adjusted RR, 0.26 [95% CI, 0.12 to 0.59]; absolute difference, -3.97% [95% CI, -6.11% to -1.82%]; P = .002). Adverse events were infrequent and similar between treatment groups (22% for sotrovimab vs 23% for placebo); the most common events were diarrhea with sotrovimab (n = 8; 2%) and COVID-19 pneumonia with placebo (n = 22; 4%).

CONCLUSIONS AND RELEVANCE

Among nonhospitalized patients with mild to moderate COVID-19 and at risk of disease progression, a single intravenous dose of sotrovimab, compared with placebo, significantly reduced the risk of a composite end point of all-cause hospitalization or death through day 29. The findings support sotrovimab as a treatment option for nonhospitalized, high-risk patients with mild to moderate COVID-19, although efficacy against SARS-CoV-2 variants that have emerged since the study was completed is unknown.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04545060.

Nirsevimab for Prevention of RSV in Healthy Late-Preterm and Term Infants

BACKGROUND

Respiratory syncytial virus (RSV) is a major cause of lower respiratory tract infection and hospitalization in infants. Nirsevimab is a monoclonal antibody to the RSV fusion protein that has an extended half-life. The efficacy and safety of nirsevimab in healthy late-preterm and term infants are uncertain.

METHODS

We randomly assigned, in a 2:1 ratio, infants who had been born at a gestational age of at least 35 weeks to receive a single intramuscular injection of nirsevimab or placebo before the start of an RSV season. The primary efficacy end point was medically attended RSV-associated lower respiratory tract infection through 150 days after the injection. The secondary efficacy end point was hospitalization for RSV-associated lower respiratory tract infection through 150 days after the injection.

RESULTS

A total of 1490 infants underwent randomization: 994 were assigned to the nirsevimab group and 496 to the placebo group. Medically attended RSV-associated lower respiratory tract infection occurred in 12 infants (1.2%) in the nirsevimab group and in 25 infants (5.0%) in the placebo group; these findings correspond to an efficacy of 74.5% (95% confidence interval [CI], 49.6 to 87.1; P<0.001) for nirsevimab. Hospitalization for RSV-associated lower respiratory tract infection occurred in 6 infants (0.6%) in the nirsevimab group and in 8 infants (1.6%) in the placebo group (efficacy, 62.1%; 95% CI, -8.6 to 86.8; P = 0.07). Among infants with data available to day 361, antidrug antibodies after baseline were detected in 58 of 951 (6.1%) in the nirsevimab group and in 5 of 473 (1.1%) in the placebo group. Serious adverse events were reported in 67 of 987 infants (6.8%) who received nirsevimab and in 36 of 491 infants (7.3%) who received placebo.

CONCLUSIONS

A single injection of nirsevimab administered before the RSV season protected healthy late-preterm and term infants from medically attended RSV-associated lower respiratory tract infection. (Funded by MedImmune/AstraZeneca and Sanofi; MELODY ClinicalTrials.gov number, NCT03979313.).

An Open Label, Adaptive, Phase 1 Trial of High-Dose Oral Nitazoxanide in Healthy Volunteers: An Antiviral Candidate for SARS-CoV-2

Repurposing approved drugs may rapidly establish effective interventions during a public health crisis. This has yielded immunomodulatory treatments for severe coronavirus disease 2019 (COVID-19), but repurposed antivirals have not been successful to date because of redundancy of the target in vivo or suboptimal exposures at studied doses. Nitazoxanide is a US Food and Drug Administration (FDA) approved antiparasitic medicine, that physiologically-based pharmacokinetic (PBPK) modeling has indicated may provide antiviral concentrations across the dosing interval, when repurposed at higher than approved doses. Within the AGILE trial platform (NCT04746183) an open label, adaptive, phase I trial in healthy adult participants was undertaken with high-dose nitazoxanide. Participants received 1,500 mg nitazoxanide orally twice-daily with food for 7 days. Primary outcomes were safety, tolerability, optimum dose, and schedule. Intensive pharmacokinetic (PK) sampling was undertaken day 1 and 5 with minimum concentration (Cmin ) sampling on days 3 and 7. Fourteen healthy participants were enrolled between February 18 and May 11, 2021. All 14 doses were completed by 10 of 14 participants. Nitazoxanide was safe and with no significant adverse events. Moderate gastrointestinal disturbance (loose stools or diarrhea) occurred in 8 participants (57.1%), with urine and sclera discoloration in 12 (85.7%) and 9 (64.3%) participants, respectively, without clinically significant bilirubin elevation. This was self-limiting and resolved upon drug discontinuation. PBPK predictions were confirmed on day 1 but with underprediction at day 5. Median Cmin was above the in vitro target concentration on the first dose and maintained throughout. Nitazoxanide administered at 1,500 mg b.i.d. with food was safe with acceptable tolerability a phase Ib/IIa study is now being initiated in patients with COVID-19.

EDP-938, a Respiratory Syncytial Virus Inhibitor, in a Human Virus Challenge

BACKGROUND

Respiratory syncytial virus (RSV) infection causes substantial morbidity and mortality among infants, older adults, and immunocompromised adults. EDP-938, a nonfusion replication inhibitor of RSV, acts by modulating the viral nucleoprotein.

METHODS

In a two-part, phase 2a, randomized, double-blind, placebo-controlled challenge trial, we assigned participants who had been inoculated with RSV-A Memphis 37b to receive EDP-938 or placebo. Different doses of EDP-938 were assessed. Nasal-wash samples were obtained from day 2 until day 12 for assessments. Clinical symptoms were assessed by the participants, and pharmacokinetic profiles were obtained. The primary end point was the area under the curve (AUC) for the RSV viral load, as measured by reverse-transcriptase-quantitative polymerase-chain-reaction assay. The key secondary end point was the AUC for the total symptom score.

RESULTS

In part 1 of the trial, 115 participants were assigned to receive EDP-938 (600 mg once daily [600-mg once-daily group] or 300 mg twice daily after a 500-mg loading dose [300-mg twice-daily group]) or placebo. In part 2, a total of 63 participants were assigned to receive EDP-938 (300 mg once daily after a 600-mg loading dose [300-mg once-daily group] or 200 mg twice daily after a 400-mg loading dose [200-mg twice-daily group]) or placebo. In part 1, the AUC for the mean viral load (hours × log10 copies per milliliter) was 204.0 in the 600-mg once-daily group, 217.7 in the 300-mg twice-daily group, and 790.2 in the placebo group. The AUC for the mean total symptom score (hours × score, with higher values indicating greater severity) was 124.5 in the 600-mg once-daily group, 181.8 in the 300-mg twice-daily group, and 478.8 in the placebo group. The results in part 2 followed a pattern similar to that in part 1: the AUC for the mean viral load was 173.9 in the 300-mg once-daily group, 196.2 in the 200-mg twice-daily group, and 879.0 in the placebo group, and the AUC for the mean total symptom score was 99.3, 89.6, and 432.2, respectively. In both parts, mucus production was more than 70% lower in each EDP-938 group than in the placebo group. The four EDP-938 regimens had a safety profile similar to that of placebo. Across all dosing regimens, the EDP-938 median time to maximum concentration ranged from 4 to 5 hours, and the geometric mean half-life ranged from 13.7 to 14.5 hours.

CONCLUSIONS

All EDP-938 regimens were superior to placebo with regard to lowering of the viral load, total symptom scores, and mucus weight without apparent safety concerns. (ClinicalTrials.gov number, NCT03691623.).

Silymarin/curcumin loaded albumin nanoparticles coated by chitosan as muco-inhalable delivery system observing anti-inflammatory and anti COVID-19 characterizations in oleic acid triggered lung injury and in vitro COVID-19 experiment

Respiratory infected by COVID-19 represents a major global health problem at moment even after recovery from virus corona. Since, the lung lesions for infected patients are still sufferings from acute respiratory distress syndrome including alveolar septal edema, pneumonia, hyperplasia, and hyaline membranes Therefore, there is an urgent need to identify additional candidates having ability to overcome inflammatory process and can enhance efficacy in the treatment of COVID-19. The polypenolic extracts were integrated into moeties of bovine serum albumin (BSA) and then were coated by chitosan as a mucoadhesion polymer. The results of interleukin-6, and c-reactive protein showed significant reduction in group treated by Encap. SIL + CUR (64 ± 0.8 Pg/μL & 6 ± 0.5 μg/μL) compared to group treated by Cham. + CUR (102 ± 0.8 Pg/μL & 7 ± 0.5 μg/μL) respectively and free capsules (with no any drug inside) (148 ± 0.6 Pg/μL & 10 ± 0.6 μg/μL) respectively. Histopathology profile was improved completely. Additionally, encapsulating silymarin showed anti-viral activity in vitro COVID-19 experiment. It can be summarized that muco-inhalable delivery system (MIDS) loaded by silymarin can be used to overcome inflammation induced by oleic acid and to overcome COVID-19.

Hepatitis C Screening and Treatment Program in Hungarian Prisons in the Era of Direct Acting Antiviral Agents

A hepatitis C virus (HCV) screening and treatment program was conducted in Hungarian prisons on a voluntary basis. After HCV-RNA testing and genotyping for anti-HCV positives, treatments with direct-acting antiviral agents were commenced by hepatologists who visited the institutions monthly. Patients were supervised by the prisons’ medical staff. Data were retrospectively collected from the Hungarian Hepatitis Treatment Registry, from the Health Registry of Prisons, and from participating hepatologists. Eighty-four percent of Hungarian prisons participated, meaning a total of 5779 individuals (28% of the inmate population) underwent screening. HCV-RNA positivity was confirmed in 317/5779 cases (5.49%); 261/317 (82.3%) started treatment. Ninety-nine percent of them admitted previous intravenous drug use. So far, 220 patients received full treatment and 41 patients are still on treatment. Based on the available end of treatment (EOT) + 24 weeks timepoint data, per protocol sustained virologic response rate was 96.8%. In conclusion, the Hungarian prison screening and treatment program, with the active participation of hepatologists and the prisons’ medical staff, is a well-functioning model. Through the Hungarian experience, we emphasize that the “test-and-treat” principle is feasible and effective at micro-eliminating HCV in prisons, where infection rate, as well as history of intravenous drug usage, are high.

A short focus, azithromycin in the treatment of respiratory viral infection COVID-19: efficacy or inefficacy?

Azithromycin is a macrolide antibiotic. Recent evidence has demonstrated in vitro activity against a wide variety of respiratory tract viruses, including SARS-CoV-2 responsible for the current global pandemic COVID-19. A mechanism of action acting on different phases of the viral cycle is assumed. In addition to its in vitro antiviral properties, some evidence also suggests immunomodulatory and antifibrotic activity. These properties of azithromycin could be useful in the treatment of viral respiratory tract infections such as COVID-19. However, clinical data on the antiviral efficacy of azithromycin in the treatment of respiratory tract infections are inconsistent, both when used as monotherapy and in polypharmacological combination. In addition, cases of azithromycin-induced QT long and malignant arrhythmias are reported. In this short review, we attempt to determine the role of azithromycin in the treatment of viral respiratory tract infections such as COVID-19, therapeutic efficacy, or inefficacy?

A critical analysis of SARS-CoV-2 (COVID-19) complexities, emerging variants, and therapeutic interventions and vaccination strategies

Coronavirus is a family of viruses that can cause diseases such as the common cold, severe acute respiratory syndrome (SARS), and Middle East respiratory syndrome (MERS). The universal outbreak of coronavirus disease 2019 (COVID-19) caused by SARS coronaviruses 2 (SARS-CoV-2) has become a global pandemic. The β-Coronaviruses, which caused SARS-CoV-2 (COVID-19), have spread in more than 213 countries, infected over 81 million people, and caused more than 1.79 million deaths. COVID-19 symptoms vary from mild fever, flu to severe pneumonia in severely ill patients. Difficult breathing, acute respiratory distress syndrome (ARDS), acute kidney disease, liver damage, and multi-organ failure ultimately lead to death. Researchers are working on different pre-clinical and clinical trials to prevent this deadly pandemic by developing new vaccines. Along with vaccines, therapeutic intervention is an integral part of healthcare response to address the ongoing threat posed by COVID-19. Despite the global efforts to understand and fight against COVID-19, many challenges need to be addressed. This article summarizes the current pandemic, different strains of SARS-CoV-2, etiology, complexities, surviving medications of COVID-19, and so far, vaccination for the treatment of COVID-19.

Tenofovir alafenamide: An initial experience at Groote Schuur Hospital, Cape Town, South Africa

BACKGROUND

Hepatitis B virus (HBV) remains endemic in South Africa (SA), with a concomitantly high prevalence of HIV co-infection. Chronic kidney disease in these subpopulations also has a high prevalence. Tenofovir is an important component of management, but the associated risk of nephrotoxicity makes dosing a challenge in patients with impaired kidney function. A new formulation, tenofovir alafenamide fumarate (TAF), with a more favourable renal toxicity profile, is now available.

OBJECTIVES

To evaluate our initial experience of TAF use at Groote Schuur Hospital, Cape Town.

METHODS

We retrospectively reviewed patients with HBV mono-infection and HIV-HBV co-infection who were initiated on TAF since 2018. We recorded all relevant demographic, serological, virological and biochemical data from patient records. Adherence was documented by pill collection at the pharmacy.

RESULTS

A total of 26 patients were included in the evaluation, median (interquartile range (IQR)) age 48 (39 - 51) years, 73% (n=19) male, 27% (n=7) hepatitis B e-antigen-positive, and 46% (n=12) HIV co-infected. The median (IQR) duration of treatment with TAF was 13 (9 - 15) months. The median (IQR) baseline creatinine level was 180 (130 - 227) µmol/L, with significant improvement at 12 months, 122 (94 - 143) µmol/L; p=0.017. Reflecting this change, the estimated glomerular filtration rate improved significantly from baseline to month 12 (42 (25 - 52) and 51 (48 - 68) mL/min/1.73 m2, respectively; p=0.023). Similarly, serum alanine aminotransferase (ALT) normalised from a baseline of 33 (18 - 52) to 18 (15 - 24) U/L at month 12 (p=0.012). HBV DNA viral load also declined, from a baseline of log10 4.04 (2.5 - 7.8) IU/mL to a median of &lt;log10 1.3 IU/mL at month 12. HIV viral load was less than the lower level of quantification at months 6 and 12.

CONCLUSIONS

TAF was well tolerated, with stable and significantly improving kidney function throughout a 12-month follow-up period. Serum ALT normalised, mirrored by declining HBV viral load. HIV viral load remained undetectable at 6 and 12 months.

Insular cortex modulates social avoidance of sick rats

Avoidance of sick individuals is vital to the preservation of one's health and preventing transmission of communicable diseases. To do this successfully, one must identify social cues for sickness, which include sickness behaviors and chemosignals, and use this information to orchestrate social interactions. While many social species are highly capable with this process, the neural mechanisms that provide for social responses to sick individuals are only partially understood. To this end, we used a task in which experimental rats were allowed to investigate two conspecifics, one healthy and one sick. To imitate sickness, one conspecific received the viral mimic Polyinosinic:polycytidylic acid (Poly I:C) and the other saline. In a 5-minute social preference test, experimental male and female adult rats avoided Poly I:C treated adult conspecifics but did not adjust social interaction in response to Poly I:C treated juvenile conspecifics. Seeking a neural locus of this behavior, we inhibited the insular cortex, a region necessary for social behaviors directed toward conspecifics in distress. Insular cortex inactivation via administration of the GABAA agonist muscimol to experimental rats prior to social preference tests eliminated the preference to avoid sick adult conspecifics. These results suggest that some aspect of conspecific illness may be encoded in the insular cortex which is anatomically positioned to coordinate a situationally appropriate social response.

Subcutaneous remdesivir administration prevents interstitial pneumonia in rhesus macaques inoculated with SARS-CoV-2

The utility of remdesivir treatment in COVID-19 patients is currently limited by the necessity to administer this antiviral intravenously, which has generally limited its use to hospitalized patients. Here, we tested a novel, subcutaneous formulation of remdesivir in the rhesus macaque model of SARS-CoV-2 infection that was previously used to establish the efficacy of remdesivir against this virus in vivo. Compared to vehicle-treated animals, macaques treated with subcutaneous remdesivir from 12 h through 6 days post inoculation showed reduced signs of respiratory disease, a reduction of virus replication in the lower respiratory tract, and an absence of interstitial pneumonia. Thus, early subcutaneous administration of remdesivir can protect from lower respiratory tract disease caused by SARS-CoV-2.

miRNAs, from Evolutionary Junk to Possible Prognostic Markers and Therapeutic Targets in COVID-19

The COVID-19 pandemic has been a public health issue around the world in the last few years. Currently, there is no specific antiviral treatment to fight the disease. Thus, it is essential to highlight possible prognostic predictors that could identify patients with a high risk of developing complications. Within this framework, miRNA biomolecules play a vital role in the genetic regulation of various genes, principally, those related to the pathophysiology of the disease. Here, we review the interaction of host and viral microRNAs with molecular and cellular elements that could potentiate the main pulmonary, cardiac, renal, circulatory, and neuronal complications in COVID-19 patients. miR-26a, miR-29b, miR-21, miR-372, and miR-2392, among others, have been associated with exacerbation of the inflammatory process, increasing the risk of a cytokine storm. In addition, increased expression of miR-15b, -199a, and -491 are related to the prognosis of the disease, and miR-192 and miR-323a were identified as clinical predictors of mortality in patients admitted to the intensive care unit. Finally, we address miR-29, miR-122, miR-155, and miR-200, among others, as possible therapeutic targets. However, more studies are required to confirm these findings.

Machine learning prediction of antiviral-HPV protein interactions for anti-HPV pharmacotherapy

Persistent infection with high-risk types Human Papillomavirus could cause diseases including cervical cancers and oropharyngeal cancers. Nonetheless, so far there is no effective pharmacotherapy for treating the infection from high-risk HPV types, and hence it remains to be a severe threat to the health of female. Based on drug repositioning strategy, we trained and benchmarked multiple machine learning models so as to predict potential effective antiviral drugs for HPV infection in this work. Through optimizing models, measuring models' predictive performance using 182 pairs of antiviral-target interaction dataset which were all approved by the United States Food and Drug Administration, and benchmarking different models' predictive performance, we identified the optimized Support Vector Machine and K-Nearest Neighbor classifier with high precision score were the best two predictors (0.80 and 0.85 respectively) amongst classifiers of Support Vector Machine, Random forest, Adaboost, Naïve Bayes, K-Nearest Neighbors, and Logistic regression classifier. We applied these two predictors together and successfully predicted 57 pairs of antiviral-HPV protein interactions from 864 pairs of antiviral-HPV protein associations. Our work provided good drug candidates for anti-HPV drug discovery. So far as we know, we are the first one to conduct such HPV-oriented computational drug repositioning study.

Intranasal priming induces local lung-resident B cell populations that secrete protective mucosal antiviral IgA

Antibodies secreted at the mucosal surface play an integral role in immune defense by serving to neutralize the pathogen and promote its elimination at the site of entry. Secretory immunoglobulin A (IgA) is a predominant Ig isotype at mucosal surfaces whose epithelial cells express polymeric Ig receptor capable of transporting dimeric IgA to the lumen. Although the role of IgA in intestinal mucosa has been extensively studied, the cell types responsible for secreting the IgA that protects the host against pathogens in the lower respiratory tract are less clear. Here, using a mouse model of influenza virus infection, we demonstrate that intranasal, but not systemic, immunization induces local IgA secretion in the bronchoalveolar space. Using single-cell RNA sequencing, we found a heterogeneous population of IgA-expressing cells within the respiratory mucosa, including tissue-resident memory B cells, plasmablasts, and plasma cells. IgA-secreting cell establishment within the lung required CXCR3. An intranasally administered protein-based vaccine also led to the establishment of IgA-secreting cells in the lung, but not when given intramuscularly or intraperitoneally. Last, local IgA secretion correlated with superior protection against secondary challenge with homologous and heterologous virus infection than circulating antibodies alone. These results provide key insights into establishment of protective immunity in the lung based on tissue-resident IgA-secreting B cells and inform vaccine strategies designed to elicit highly effective immune protection against respiratory virus infections.

Huaier granule prevents the recurrence of early-stage hepatocellular carcinoma after thermal ablation: A cohort study

ETHNOPHARMACOLOGICAL RELEVANCE

Clinical trials have demonstrated that Trametes robinophila Murr (Huaier granule) can inhibit recurrence and metastasis after hepatocellular carcinoma (HCC) resection, but its efficacy as an adjuvant therapy after thermal ablation of early HCC is unknown.

AIM OF THE STUDY

To analyze the prognostic value and side effects of Huaier granules in HCC patients undergoing thermal ablation.

MATERIALS AND METHODS

Clinical information from 340 eligible subjects with early-stage HCC who were admitted to our department from September 1, 2008 to January 1, 2019 was extracted from the electronic medical record database. They were divided into the thermal ablation + TCM group and the thermal ablation group. Differences in their overall survival (OS), progression-free survival (PFS), extrahepatic metastatic rate (EMR), and therapeutic side effects (TSEs) between the two groups were compared. Beneficiaries of the integrated treatment and adequate treatment length were predicted.

RESULTS

The median follow-up was 32.5 months (range 2-122 months). The 1-year, 3-year and 5-year OS rates in the integrated treatment group and the control group were 93.2% vs. 92.6%, 54.5% vs. 51.4%, 23.5% vs. 19.7% (p = 0.110, HR 0.76(0.54-1.07)). The 1-year, 3-year and 5-year PFS rates were 78.8% vs. 69.4%, 50.6% vs. 40.6%, 35.3% vs. 26.5%, respectively (p = 0.020, HR 0.67(0.48-0.94)). The median OS (35 vs. 31 months) and PFS (24 vs. 12.5 months) were longer in the integrated treatment group. The EMR in the integrated treatment group was significantly lower than that in the control group (p = 0.018, HR 0.49 (0.27-0.89)). Patients with any two of the following three factors might be predicted to be beneficiaries of the integrated treatment, including younger than 65 years (p =0.039, HR 0.70 (0.50-0.98)), single tumor (p = 0.035, HR 0.70 (0.50-0.98), and tumor size ≤3 cm (p = 0.029, HR 0.69 (0.50-0.96). Patients with continuous oral administration of TCM following ablation had a lower probability of recurrence and metastasis within 2 years (p = 0.015, HR 0.67 (0.49-0.93)). Although the integrated treatment group reported a higher incidence of nausea and emesis, there were no significant differences between the two groups.

CONCLUSION

TCM following ablation may prolong PFS and suppress recurrence in patients with HCC, with continuous oral administration for more than 2 years maybe experience a greater benefit. The TSEs of the treatment are mild and can be tolerated.

REGEN-COV Antibody Combination and Outcomes in Outpatients with Covid-19

BACKGROUND

In the phase 1-2 portion of an adaptive trial, REGEN-COV, a combination of the monoclonal antibodies casirivimab and imdevimab, reduced the viral load and number of medical visits in patients with coronavirus disease 2019 (Covid-19). REGEN-COV has activity in vitro against current severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants of concern.

METHODS

In the phase 3 portion of an adaptive trial, we randomly assigned outpatients with Covid-19 and risk factors for severe disease to receive various doses of intravenous REGEN-COV or placebo. Patients were followed through day 29. A prespecified hierarchical analysis was used to assess the end points of hospitalization or death and the time to resolution of symptoms. Safety was also evaluated.

RESULTS

Covid-19-related hospitalization or death from any cause occurred in 18 of 1355 patients in the REGEN-COV 2400-mg group (1.3%) and in 62 of 1341 patients in the placebo group who underwent randomization concurrently (4.6%) (relative risk reduction [1 minus the relative risk], 71.3%; P<0.001); these outcomes occurred in 7 of 736 patients in the REGEN-COV 1200-mg group (1.0%) and in 24 of 748 patients in the placebo group who underwent randomization concurrently (3.2%) (relative risk reduction, 70.4%; P = 0.002). The median time to resolution of symptoms was 4 days shorter with each REGEN-COV dose than with placebo (10 days vs. 14 days; P<0.001 for both comparisons). REGEN-COV was efficacious across various subgroups, including patients who were SARS-CoV-2 serum antibody-positive at baseline. Both REGEN-COV doses reduced viral load faster than placebo; the least-squares mean difference in viral load from baseline through day 7 was -0.71 log10 copies per milliliter (95% confidence interval [CI], -0.90 to -0.53) in the 1200-mg group and -0.86 log10 copies per milliliter (95% CI, -1.00 to -0.72) in the 2400-mg group. Serious adverse events occurred more frequently in the placebo group (4.0%) than in the 1200-mg group (1.1%) and the 2400-mg group (1.3%); infusion-related reactions of grade 2 or higher occurred in less than 0.3% of the patients in all groups.

CONCLUSIONS

REGEN-COV reduced the risk of Covid-19-related hospitalization or death from any cause, and it resolved symptoms and reduced the SARS-CoV-2 viral load more rapidly than placebo. (Funded by Regeneron Pharmaceuticals and others; ClinicalTrials.gov number, NCT04425629.).

Pharmacokinetics-based identification of pseudoaldosterogenic compounds originating from Glycyrrhiza uralensis roots (Gancao) after dosing LianhuaQingwen capsule

LianhuaQingwen capsule, prepared from an herbal combination, is officially recommended as treatment for COVID-19 in China. Of the serial pharmacokinetic investigations we designed to facilitate identifying LianhuaQingwen compounds that are likely to be therapeutically important, the current investigation focused on the component Glycyrrhiza uralensis roots (Gancao). Besides its function in COVID-19 treatment, Gancao is able to induce pseudoaldosteronism by inhibiting renal 11β-HSD2. Systemic and colon-luminal exposure to Gancao compounds were characterized in volunteers receiving LianhuaQingwen and by in vitro metabolism studies. Access of Gancao compounds to 11β-HSD2 was characterized using human/rat, in vitro transport, and plasma protein binding studies, while 11β-HSD2 inhibition was assessed using human kidney microsomes. LianhuaQingwen contained a total of 41 Gancao constituents (0.01-8.56 μmol/day). Although glycyrrhizin (1), licorice saponin G2 (2), and liquiritin/liquiritin apioside (21/22) were the major Gancao constituents in LianhuaQingwen, their poor intestinal absorption and access to colonic microbiota resulted in significant levels of their respective deglycosylated metabolites glycyrrhetic acid (8), 24-hydroxyglycyrrhetic acid (M2D; a new Gancao metabolite), and liquiritigenin (27) in human plasma and feces after dosing. These circulating metabolites were glucuronized/sulfated in the liver and then excreted into bile. Hepatic oxidation of 8 also yielded M2D. Circulating 8 and M2D, having good membrane permeability, could access (via passive tubular reabsorption) and inhibit renal 11β-HSD2. Collectively, 1 and 2 were metabolically activated to the pseudoaldosterogenic compounds 8 and M2D. This investigation, together with such investigations of other components, has implications for precisely defining therapeutic benefit of LianhuaQingwen and conditions for its safe use.

Noninvasive Assessment of Fibrosis Regression after Direct-acting Antiviral Treatment in Hepatitis C Virus Patients

BACKGROUND

New direct acting antiviral agent (DAA) therapies are associated with a high sustained virological response rate (SVR) in hepatitis C virus (HCV) patients. The understanding of the impact of SVR on fibrosis stage is limited.

OBJECTIVES

To determine the effect of treatment with the DAAs on long-term liver fibrosis stages, as determined by shear-wave elastography (SWE) or FibroTest.

METHODS

Fibrosis stage was determined at baseline and at 6-month intervals after end of treatment (EOT), using two-dimensional SWE or FibroTest©; APRI and FIB-4 scores.

RESULTS

The study comprised 133 SVR12 patients. After a median follow-up of 15 months (range 6-33), liver fibrosis stage decreased by at least 1 stage in 75/133 patients (56%). Cirrhosis reversal was observed in 24/82 (29%). Repeated median liver stiffness SWE values in cirrhotic patients were 15.1 kPa at baseline (range 10.5-100), 13.4 kPa (range 5.5-51) at 6 months, and 11.4 kPa (range 6.1-35.8) at 12 months after EOT, P = 0.01. During the second year after EOT, no statistically significant differences in liver fibrosis stage in 12, 18, and 24 months were found. Splenomegaly was the only significant negative predictor of liver fibrosis regression during all time points of repetitive noninvasive assessment.

CONCLUSIONS

Following successful DAA treatment, the majority of our HCV patients with advanced fibrosis demonstrated significant improvement, as assessed by non-invasive methods. Advanced fibrosis stage was a negative predictor of fibrosis regression. Longer follow-up periods are required to further establish the impact of DAAs treatment in HCV patients with advanced fibrosis.

18β-Glycyrrhetinic acid inhibits the apoptosis of cells infected with rotavirus SA11 via the Fas/FasL pathway

CONTEXT

18β-Glycyrrhetinic acid (18β-GA), a pentacyclic triterpenoid saponin metabolite of glycyrrhizin, exhibits several biological activities.

OBJECTIVE

We investigated the effects of 18β-GA on MA104 cells infected with rotavirus (RV) and its potential mechanism of action.

MATERIALS AND METHODS

Cell Counting Kit-8 was used to assess tissue culture infective dose 50 (TCID₅₀) and 50% cellular cytotoxicity (CC₅₀) concentration. MA104 cells infected with RV SA11 were treated with 18β-GA (1, 2, 4, and 8 μg/mL, respectively). Cytopathic effects were observed. The virus inhibition rate, concentration for 50% of maximal effect (EC₅₀), and selection index (SI) were calculated. Cell cycle, cell apoptosis, and mRNA and protein expression related to the Fas/FasL pathway were detected.

RESULTS

TCID₅₀ of RV SA11 was 10^-4.47/100 µL; the CC₅₀ of 18β-GA on MA104 cells was 86.92 µg/mL. 18β-GA showed significant antiviral activity; EC₅₀ was 3.14 μg/mL, and SI was 27.68. The ratio of MA104 cells infected with RV SA11 in the G0/G1 phase and the G2/M phase decreased and increased, respectively, after 18β-GA treatment. 18β-GA significantly induced apoptosis in the infected cells. Furthermore, after 18β-GA treatment, the mRNA and protein expression levels of Fas, FasL, caspase 3, and Bcl-2 decreased, whereas the expression levels of Bax increased.

DISCUSSION AND CONCLUSIONS

The study demonstrates that 18β-GA may be a promising candidate for the treatment of RV SA11 infection and provides theoretical support for the clinical development of glycyrrhizic acid compounds for the treatment of RV infection.

SARS-CoV-2 infection and disease outcomes in non-human primate models: advances and implications

SARS-CoV-2 has been the causative pathogen of the pandemic of COVID-19, resulting in catastrophic health issues globally. It is important to develop human-like animal models for investigating the mechanisms that SARS-CoV-2 uses to infect humans and cause COVID-19. Several studies demonstrated that the non-human primate (NHP) is permissive for SARS-CoV-2 infection to cause typical clinical symptoms including fever, cough, breathing difficulty, and other diagnostic abnormalities such as immunopathogenesis and hyperplastic lesions in the lung. These NHP models have been used for investigating the potential infection route and host immune response to SARS-CoV-2, as well as testing vaccines and drugs. This review aims to summarize the benefits and caveats of NHP models currently available for SARS-CoV-2, and to discuss key topics including model optimization, extended application, and clinical translation.

Role of microRNAs in COVID-19 with implications for therapeutics

COVID-19 is a pneumonia-like disease with highly transmittable and pathogenic properties caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which infects both animals and humans. Although many efforts are currently underway to test possible therapies, there is no specific FDA approved drug against SARS-CoV-2 yet. miRNA-directed gene regulation controls the majority of biological processes. In addition, the development and progression of several human diseases are associated with dysregulation of miRNAs. In this regard, it has been shown that changes in miRNAs are linked to severity of COVID-19 especially in patients with respiratory diseases, diabetes, heart failure or kidney problems. Therefore, targeting these small noncoding-RNAs could potentially alleviate complications from COVID-19. Here, we will review the roles and importance of host and RNA virus encoded miRNAs in COVID-19 pathogenicity and immune response. Then, we focus on potential miRNA therapeutics in the patients who are at increased risk for severe disease.

A Pragmatic, Randomized Controlled Trial of Oral Antivirals for the Treatment of Chronic Hepatitis C: The PRIORITIZE Study

BACKGROUND AND AIMS

Multiple direct-acting antiviral (DAA) regimens are available to treat HCV genotype 1 infection. However, comparative effectiveness from randomized controlled trials of DAA regimens is unavailable.

APPROACH AND RESULTS

We conducted a pragmatic randomized controlled trial (NCT02786537) to compare the effectiveness of DAAs for HCV genotype 1a or 1b on viral response, safety, tolerability, and medication nonadherence. Adults with compensated liver disease, HCV genotype 1, not pregnant or breastfeeding, and with health insurance likely to cover ledipasvir/sofosbuvir (LDV/SOF) were recruited from 34 US viral hepatitis clinics. Participants were randomized (± ribavirin) to LDV/SOF, elbasvir/grazoprevir (EBR/GZR), and paritaprevir/ritonavir/ombitasvir+dasabuvir (PrOD; treatment arm stopped early). Primary outcomes included sustained viral response at 12 weeks (SVR12), clinician-recorded adverse events, patient-reported symptoms, and medication nonadherence. Between June 2016 and March 2018, 1,609 participants were randomized. Among 1,128 participants who received ≥1 dose of EBR/GZR or LDV/SOF (± ribavirin), SVR12 was 95.2% (95% CI, 92.8%-97.6%) and 97.4% (95% CI, 95.5%-99.2%), respectively, with a difference estimate of 2.2% (-0.5% to 4.7%), falling within the "equivalence" interval (-5% to 5%). While most (56%) participants experienced adverse events, few were serious (4.2%) or severe (1.8%). In the absence of ribavirin, discontinuations due to adverse events were rare. Patient-reported symptoms and medication nonadherence were similar. Study limitations were dropout due to insurance denial and loss to follow-up after treatment, limiting the ability to measure SVR12.

CONCLUSIONS

This pragmatic trial demonstrated high SVR12 for participants treated with EBR/GZR and LDV/SOF with few adverse effects. Overall, the two regimens were equivalent in effectiveness. The results support current HCV guidelines that do not distinguish between ribavirin-free EBR/GZR and LDV/SOF.

Effect of delayed palivizumab administration on respiratory syncytial virus infection-related hospitalisation: A retrospective, observational study

Respiratory syncytial virus (RSV) infection is an important cause of hospitalization in infants and young children. Monthly administration of palivizumab during the RSV season is effective in preventing severe infections in children with comorbidities. However, determining the onset of the RSV season for starting palivizumab is often challenging. The present study aimed to evaluate the ideal timing to start palivizumab and its effect on hospitalization in the real world.We performed a retrospective, observational study to identify the relationship between the timing of the first dose of palivizumab administration and RSV-related hospitalization. Medical records from 2015 to 2019 were reviewed. We included patients who had indications for palivizumab as of July 1 in each year. We counted the proportion of children receiving palivizumab and the number of RSV infection-related hospitalizations each month. We also evaluated the differences in background and underlying disease between children with and without hospitalization.A total of 498 patients were included, and 105 (21.0%) completed the first dose in July when the RSV season usually begins in Japan. Twenty-three (4.6%) patients were hospitalized for RSV infection during the observation period, with 13 (56.5%) hospitalizations before their first dose of palivizumab. The remaining 10 patients were hospitalized after receiving 1 or more doses of palivizumab. Children living with siblings and children with cyanosis originating from congenital heart disease had a higher risk of RSV with odds ratios of 5.1 (95% confidence interval 1.48-17.6, P < .01) and 3.3 (95% confidence interval 1.33-7.94, P < .01), respectively.Delays in administering palivizumab at the beginning of the season increases the rate of RSV infection-related hospitalization. To maximize prophylactic effectiveness, administering the first dose as early as possible in the RSV season is crucial, with priority for cyanotic children or those with siblings.