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480 result(s) for "Hepatitis B Surface Antigens - pharmacology"
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Immunogenicity and Safety of a 3-Antigen Hepatitis B Vaccine vs a Single-Antigen Hepatitis B Vaccine
There is a need for improved immunogenicity of hepatitis B virus (HBV) vaccines among young adults with risk of infection. To demonstrate manufacturing equivalence of a 3-antigen (3A) HBV vaccine, evaluate noninferiority of seroprotection rate (SPR) of 3A-HBV vs single-antigen (1A) HBV after 2 and 3 vaccine doses, and compare safety and reactogenicity between 3A-HBV and 1A-HBV vaccines. This phase 3, double-blinded, randomized clinical trial included healthy adults aged 18 to 45 years randomized to 1 of three 3A-HBV groups or 1 control group receiving 1A-HBV. The trial was conducted at 37 community clinics and academic hospitals in Canada, Europe, the United Kingdom, and the United States between December 2017 and October 2019. Participants were followed up for 48 weeks after the first vaccination. Intramuscular administration of 3A-HBV (10 μg) or 1A-HBV (20 μg) on days 0, 28, and 168. Geometric mean concentration (GMC) of serum hepatitis B surface antibodies (anti-HBs) and proportion of participants achieving seroprotection. Of 2838 participants, 1638 (57.8%) were women, 2595 (91.5%) were White, and 161 (5.7%) were Black or African American. A total of 712 participants (25.1%) were randomized to the 1A-HBV group and 2126 (74.9%) to 3A-HBV. The mean (SD) age at informed consent was 33.5 (8.0) years. The study demonstrated 3A-HBV lot-to-lot consistency, as the 2-sided 95% CIs for each pairwise comparison for the anti-HBs GMC ratios were within 0.67 and 1.50 (eg, adjusted GMC ratio, lot A vs lot B: 0.82; 95% CI, 0.67-1.00; lot A vs lot C: 0.95; 95% CI, 0.78-1.15; lot B vs lot C: 1.16; 95% CI, 0.95-1.41). The SPR of the pooled 3A-HBV was noninferior to 1A-HBV and higher than 1A-HBV after 2 vaccinations at day 168 (90.4% [95% CI, 89.0%-91.8%] vs 51.6% [95% CI, 47.5%-55.6%]) and 3 vaccinations at day 196 (99.3% [95% CI, 98.7%-99.6%] vs 94.8% [95% CI, 92.7%-96.4%]). The mean GMC of anti-HBs with 3A-HBV was 7.9 times higher after 2 vaccinations at day 168 and 3.5 times higher after 3 vaccinations at day 196 compared with 1A-HBV (after 2 vaccinations, 3A-HBV: GMC, 118.7 mIU/mL; 95% CI, 108.0-129.0 mIU/mL; SE, 1.0 mIU/mL; 1A-HBV: GMC, 15.0 mIU/mL; 95% CI, 12.9-17.5 mIU/mL; SE, 1.0 mIU/mL; after 3 vaccinations, 3A-HBV: GMC, 5442.4 mIU/mL; 95% CI, 4967.0-5963.0 mIU/mL; SE, 1.0 mIU/mL; 1A-HBV: 1567.2 mIU/mL; 95% CI, 1338.0-1834.0 mIU/mL; SE, 1.0 mIU/mL). Rates of local and systemic reactogenicities were higher with 3A-HBV compared with 1A-HBV (local: 1805 of 2124 [85.0%] vs 469 of 712 [65.9%]; systemic: 1445 [68.0%] vs 428 [60.1%]). Vaccine discontinuation due to adverse events (AE) was uncommon, and serious AEs were infrequent, reported in 42 participants (2.0%) and 3 participants (0.4%) in the 3A-HBV and 1A-HBV groups, respectively. In this study, consistently higher antibody concentrations and SPRs were found with 3A-HBV after 2 and 3 doses vs 1A-HBV in adults aged 18 to 45 years old. The safety and efficacy of 3A-HBV shows its usefulness for the prevention of hepatitis B in young healthy adults. Clinicaltrials.gov Identifier: NCT03408730; EU Clinical Trials Number: 2017-001820-22.
Emerging Therapies for Chronic Hepatitis B and the Potential for a Functional Cure
Worldwide, an estimated 296 million people are living with chronic hepatitis B virus (HBV) infection, with a significant risk of morbidity and mortality. Current therapy with pegylated interferon (Peg-IFN) and indefinite or finite therapy with nucleoside/nucleotide analogues (Nucs) are effective in HBV suppression, hepatitis resolution, and prevention of disease progression. However, few achieve hepatitis B surface antigen (HBsAg) loss (functional cure), and relapse often occurs after the end of therapy (EOT) because these agents have no direct effect on durable template: covalently closed circular DNA (cccDNA) and integrated HBV DNA. Hepatitis B surface antigen loss rate increases slightly by adding or switching to Peg-IFN in Nuc-treated patients and this loss rate greatly increases up to 39% in 5 years with finite Nuc therapy with currently available Nuc(s). For this, great effort has been made to develop novel direct-acting antivirals (DAAs) and immunomodulators. Among the DAAs, entry inhibitors and capsid assembly modulators have little effect on reducing HBsAg levels; small interfering RNA, antisense oligonucleotides, and nucleic acid polymers in combination with Peg-IFN and Nuc may reduce HBsAg levels significantly, even a rate of HBsAg loss sustained for > 24 weeks after EOT up to 40%. Novel immunomodulators, including T-cell receptor agonists, check-point inhibitors, therapeutic vaccines, and monoclonal antibodies may restore HBV-specific T-cell response but not sustained HBsAg loss. The safety issues and the durability of HBsAg loss warrant further investigation. Combining agents of different classes has the potential to enhance HBsAg loss. Compounds directly targeting cccDNA would be more effective but are still in the early stage of development. More effort is required to achieve this goal.
Enhancing protective immunity to malaria with a highly immunogenic virus-like particle vaccine
The leading malaria vaccine in development is the circumsporozoite protein (CSP)-based particle vaccine, RTS,S, which targets the pre-erythrocytic stage of Plasmodium falciparum infection. It induces modest levels of protective efficacy, thought to be mediated primarily by CSP-specific antibodies. We aimed to enhance vaccine efficacy by generating a more immunogenic CSP-based particle vaccine and therefore developed a next-generation RTS,S-like vaccine, called R21. The major improvement is that in contrast to RTS,S, R21 particles are formed from a single CSP-hepatitis B surface antigen (HBsAg) fusion protein, and this leads to a vaccine composed of a much higher proportion of CSP than in RTS,S. We demonstrate that in BALB/c mice R21 is immunogenic at very low doses and when administered with the adjuvants Abisco-100 and Matrix-M it elicits sterile protection against transgenic sporozoite challenge. Concurrent induction of potent cellular and humoral immune responses was also achieved by combining R21 with TRAP-based viral vectors and protective efficacy was significantly enhanced. In addition, in contrast to RTS,S, only a minimal antibody response to the HBsAg carrier was induced. These studies identify an anti-sporozoite vaccine component that may improve upon the current leading malaria vaccine RTS,S. R21 is now under evaluation in Phase 1/2a clinical trials.
Hepatitis B virus reactivation in patients undergoing immune checkpoint inhibition: systematic review with meta-analysis
Purpose Immune checkpoint inhibitors (ICIs) have been explored as first-line treatment in various types of previously untreatable malignancies, while limited evidence is available on the management of hepatitis B virus (HBV) in patients undergoing immunotherapy. We systematically reviewed data concerning challenges of hepatic adverse events including HBV reactivation and hepatitis in patients with chronic HBV infection undergoing immunotherapy. Methods A systematic search was conducted in Medline, web of science, Embase and Cochrane library up to May 31, 2022. Studies reporting the safety profile of ICIs in patients with HBV infection were eligible. Meta-analyses were conducted to generate odds ratios (ORs) with 95% confidence intervals (CIs). Results A total of 13 studies including 2561 patients were included for meta-analysis. The overall incidence rates of HBV reactivation in patients with chronic HBV infection and past HBV infection were 1.0% (95% CI 0–3%) and 0% (95% CI 0–0%), respectively. Among patients with chronic HBV infection, the incidence rates of HBV reactivation were 1.0% (95% CI 0–2%) and 10.0% (95% CI 4–18%) for patients with and without antiviral prophylaxis, respectively. Patients with chronic HBV infection were at a higher risk of HBV reactivation compared with those with past HBV infection [OR = 8.69, 95% CI (2.16–34.99)]. Antiviral prophylaxis significantly reduced the risk of HBV reactivation [OR = 0.12, 95% CI (0.02–0.67)] and HBV-associated hepatitis [OR = 0.05, 95% CI (0.01–0.28)] in patients with chronic HBV infection. Conclusions Prophylactic antiviral therapy should be administered to patients with chronic HBV infection undergoing anticancer immunotherapy. Patients with past HBV infection are at lower risk of HBV reactivation compared with those with chronic HBV infection, they could be initiated with antiviral prophylaxis or monitored with the intent of on-demand antiviral therapy.
Hepatitis Virus Reactivation in Patients with Psoriasis Treated with Secukinumab in a Real-World Setting of Hepatitis B or Hepatitis C Infection
Background and Objective Biologics for psoriasis, especially anti-tumor necrosis factor-α therapies, may reactivate hepatitis B virus (HBV) or hepatitis C virus (HCV) infections, as well in inactive carriers or patients with occult infection. However, some biologics, including anti-interleukin-17 therapies such as secukinumab, seem to be less likely to cause hepatitis reactivation. This study assessed the safety of secukinumab treatment in patients with psoriasis with HBV or HBC infection. Methods This was a retrospective cohort study of patients with moderate-to-severe psoriasis treated with secukinumab at seven Italian centers. Patients serologically positive for one or more of the following viral hepatitis markers were included: HCV antibody (± HCV-RNA positivity) and/or hepatitis B surface antigen, and/or HBV core antibody and/or HBV surface antibody (± HBV-DNA positivity). Patients received secukinumab 300 mg subcutaneously at week 0/1/2/3/4 then every 4 weeks; prophylactic therapy before starting secukinumab was prescribed where indicated. The primary study endpoint was the reactivation of hepatitis viral infection, defined as conversion to HBV-DNA or HCV-RNA positivity, with or without elevation of transaminases. Results Sixty patients (17 with concomitant psoriatic arthritis) were included. Thirteen subjects were hepatitis B surface antigen positive, 19 were HBV core antibody positive, and 30 were positive for the HCV antibody; however, all were HCV-RNA negative. After 53.5 ± 37.5 weeks of secukinumab therapy, hepatitis reactivation occurred in only one patient, who had a reactivation of both hepatitis B and hepatitis C. This patient had not undergone hepatitis B prophylaxis or hepatitis C treatment before secukinumab. Conclusions These real-world data support the safety of secukinumab in patients with positive markers of HBV or HCV infection, when administered together with dedicated prophylaxis. Plain Language Summary In this retrospective cohort study, 60 patients with moderate-to-severe psoriasis were treated with secukinumab at seven Italian centers. Secukinumab is a fully human monoclonal antibody targeting interleukin-17A, a key cytokine associated with the development of psoriatic disease. All patients had markers of hepatitis B and/or C. Where appropriate, patients received prophylactic antiviral therapy before starting secukinumab at the standard dose for treating psoriasis in Italy. Secukinumab was administered at the labeled dose. After a mean duration treatment of 53.5 weeks, hepatitis reactivation (both B and C) occurred in one patient. This patient had not undergone hepatitis B prophylaxis or hepatitis C treatment before receiving secukinumab. The study is important, as some biologics for psoriasis, especially anti-tumor necrosis factor-α therapies, have been shown to reactivate both hepatitis B virus or hepatitis C virus infections in inactive carriers, patients with occult hepatitis B virus infection, or patients with hepatitis C virus infections. However, there is evidence that second-generation biologic therapies, including those with anti-interleukin-17 activity, are less likely to cause hepatitis reactivation. This study supports the safety of secukinumab treatment in patients with psoriasis with hepatitis B and/or C.
Hepatotoxicity associated with PD-1 blockade antibodies in cancer patients co-infected with hepatitis B virus
The use of anti-programmed cell death-1 (PD-1) antibodies in treating malignancies is increasing; however, most registered clinical trials on anti-PD-1 antibodies exclude patients infected with hepatitis B virus (HBV). This retrospective study aimed to assess hepatotoxicity in cancer patients infected with HBV undergoing anti-PD1 antibody therapy and identify the associated risk factors. A total of 301 cancer patients positive for hepatitis B core antibodies (HbcAb) (negative or positive hepatitis B surface antigen [HBsAg]) who received PD-1 inhibitors were enrolled. The primary and secondary endpoints were the incidence rate of hepatotoxicity related to PD-1 inhibitor treatment, and risk factors associated with hepatic toxicity, respectively. Of the enrolled analyzed, 16.9% (n = 51) developed any grade and 4.7% (n = 14) developed grade 3–4 hepatotoxicity, respectively. Higher risk for any-grade hepatotoxicity development was associated with sero-positive HBsAg (OR = 6.30; P = 0.020), existence of liver involvement (OR = 2.10; P = 0.030), and detectable baseline HBV DNA levels (OR = 2.39; P = 0.012). Patients with prophylactic antiviral therapy decreased hazard for the incidence of grade 3–4 hepatotoxicity (OR = 0.10; P = 0.016). Our results suggested chronic (HBsAg-positive)/resolved (HBsAg-negative and HBcAb-positive) HBV-infected cancer patients are at an increased risk of hepatotoxicity following PD-1 inhibitor therapy. Cancer patients should be tested for HBsAg/HBcAb prior to the commencement of immune checkpoint inhibitor therapy. For patients with chronic/resolved HBV infection, ALT/AST and HBV DNA should be closely monitored during the whole immunotherapy period.
Hepatitis D Virus and HBsAg Dynamics in the era of new Antiviral Treatments
Purpose of Review Hepatitis D virus (HDV) infection is the most severe form of chronic viral hepatitis, with no FDA-approved therapy. Progress in the development of effective HDV treatments is accelerating. This review highlights how mathematical modeling is improving understanding of HDV-HBsAg-host dynamics during antiviral therapy and generating insights into the efficacy and modes of action (MOA) of new antiviral agents. Recent Findings Clinical trials with pegylated-interferon-λ, bulevertide, nucleic acid polymers, and/or lonafarnib against various steps of the HDV-life cycle have revealed new viral-kinetic patterns that were not observed under standard treatment with pegylated-interferon-α. Modeling indicated that the half-lives of circulating HDV and HBsAg are ~ 1.7 d and ~ 1.3 d, respectively, estimated the relative response of HDV and HBsAg during different antiviral therapies, and provided insights into the efficacy and MOA of drugs in development for treating HDV, which can inform response-guided therapy to individualize treatment duration. Summary Mathematical modeling of HDV and HBsAg kinetics provides a window into the HDV virus lifecycle, HDV-HBsAg-host dynamics during antiviral therapy, and the MOA of new drugs for HDV.
NLRX1 can counteract innate immune response induced by an external stimulus favoring HBV infection by competitive inhibition of MAVS-RLRs signaling in HepG2-NTCP cells
Introduction This study is aimed at the determination of the effect of the immune-regulatory factor NLRX1 on the antiviral activity of hepatocytes against an external stimuli favoring hepatitis B virus infection, and to explore its mechanism of action. Methods A HepG2-NTCP model was established using the LV003 lentivirus. Cells were transfected using an overexpression vector and NLRX1 siRNA to achieve overexpression and interference of NLRX1 expression (OV-NLRX1, si-NLRX1). Levels of HBsAg and HBcAg were determined using Western blotting analysis and immunohistochemical analysis. The levels of hepatitis B virus DNA and hepatitis B virus cccDNA were determined by real-time quantitative polymerase chain reaction. The expression and transcriptional activity of IFN-α, IFN-β, and IL-6 were measured using real-time quantitative polymerase chain reaction, enzyme-linked immunosorbent assay, and promoter-luciferase reporter plasmids. Co-immunoprecipitation was used to determine the effect of NLRX1 on the interaction between MAVS and RIG-1. Western blotting was used to obtain the phosphorylation of essential proteins in the MAVS-RLRs signaling pathways. Results NLRX1 promoted HepG2-NTCP cell hepatitis B virus infection. Compared to the control group, the levels of HBsAg, HBcAg, hepatitis B virus cccDNA, and hepatitis B virus DNA increased in the OV-NLRX1 group and decreased in the si-NLRX1. Co-immunoprecipitation results showed that NLRX1 competitively inhibited the interaction between MAVS and RIG-1, and inhibited the phosphorylation of p65, IRF3, and IRF7. Additionally, NLRX1 reduced the transcription activity and expression levels of the final products: IFN-α, IFN-β, and IL-6. Conclusions NLRX1 can counteract innate immune response induced by an external stimuli favoring hepatitis B virus infection by competitive inhibition of MAVS-RLRs signaling in HepG2-NTCP cells. Inhibition of the MAVS-RLR-mediated signaling pathways leads to a decline in the expression levels of I-IFN and IL-6.
Long-term follow-up of treatment-naïve HBeAg-negative patients with chronic hepatitis B
Background/aims We aimed to explore long-term results of oral antiviral agents in treatment-naïve “HBeAg negative chronic hepatitis B (CHB)” and determine the factors affecting the complete virological response. Method Patients with HBeAg-negative CHB who used oral antiviral agents for at least 3 years were evaluated retrospectively. Results A total of 173 patients were recorded. The mean duration of treatment was 62.2 ± 28.9 months. Complete virological responses (CVR) were 82.8% ( n  = 53/64) in tenofovir disoproxil fumarate (TDF), 84.4% ( n  = 49/58) in lamivudine (LAM), 83.9% ( n  = 26/31) in entecavir (ETV), 95% in telbivudine (LdT) ( n  = 19/20) ( p  = 0.290). Multivariate analysis revealed age ≤ 40 ( p  = 0.012, 95%CI = 1.38–13.76, OR = 4.36) and baseline HBV DNA value ( p  = 0.003, 95%CI = 1.23–2.63, OR = 1.78) as independent factors for CVR. Virological breakthrough was detected in 29 (50%) patients on LAM therapy, two (6.4%) patients on ETV therapy, and two (10%) patients on LdT therapy. Treatment was switched to another antiviral agent due to osteoporosis in four patients in the TDF group, muscle pain in nine patients in the LDT group, and headache in one patient in the ETV group. Hepatocelluler cancer was detected in five patients. HBsAg seroclearance developed in two patients. Anti-HBs seroconversion was not detected. Conclusion CVR was achieved at similar rates with all four antiviral agents, while younger age (≤ 40) and low baseline viral load were the main factors for virological response. However, drug resistance and virological breakthrough in the LAM group and side effects in the LdT group were detected during the long-term follow-up. Moreover, HBsAg seroclearance was achieved at very low rates with oral antiviral agents.
Effects of Hepatitis B Virus S Protein Exposure on Sperm Membrane Integrity and Functions
Hepatitis B is a public health problem worldwide. Viral infection can affect a man's fertility, but only scant information about the influence of hepatitis B virus (HBV) infection on sperm quality is available. The purpose of this study was to investigate the effect of hepatitis B virus S protein (HBs) on human sperm membrane integrity and functions. Reactive oxygen species (ROS), lipid peroxidation (LP), total antioxidant capacity (TAC) and phosphatidylserine (PS) externalization were determined. The terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assays and flow cytometric analyses were performed. (1) After 3 h incubation with 25 µg/ml of HBs, the average rates of ROS positive cells, annexin V-positive/propidium iodide (PI)-negative cells, Caspases-3,-8,-9 positive cells and TUNEL-positive cells were significantly increased in the test groups as compared to those in the control groups, while TAC level was decreased when compared with the control. The level of malondialdehyde (MDA) in the sperm cells exposed to 50 µg/ml of HBs for 3 h was significantly higher than that in the control (P<0.05-0.01). (2) HBs increased the MDA levels and the numbers of ROS positive cells, annexin V-positive/PI-negative cells, caspases-3, -8, -9 positive cells and TUNEL-positive cells in a dose-dependent manner. (3) HBs monoclonal antibody (MAb) and N-Acetylcysteine (NAC) reduced the number of ROS-positive sperm cells. (4) HBs decreased the TAC levels in sperm cells in a dose-dependent manner. HBs exposure could lead to ROS generation, lipid peroxidation, TAC reduction, PS externalization, activation of caspases, and DNA fragmentation, resulting in increased apoptosis of sperm cells and loss of sperm membrane integrity and causing sperm dysfunctions.