Postexposure prophylactic effect of hepatitis B virus (HBV)-active antiretroviral therapy against HBV infection

An ultralong-acting tenofovir ProTide nanoformulation achieves monthslong HBV suppression

Treatment of chronic hepatitis B virus (HBV) requires lifelong daily therapy. However, suboptimal adherence to the existing daily therapy has led to the need for ultralong-acting antivirals. A lipophilic and hydrophobic ProTide was made by replacing the alanyl isopropyl ester present in tenofovir alafenamide (TAF) with a docosyl phenyl alanyl ester, now referred to as M1TFV. NM1TFV and nanoformulated TAF (NTAF) nanocrystals were formulated by high-pressure homogenization. A single intramuscular injection of NM1TFV, but not NTAF, delivered at a dose of TFV equivalents (168 milligrams per kilogram) demonstrated monthslong antiviral activities in both HBV-transgenic and human hepatocyte transplanted TK-NOG mice. The suppression of HBV DNA in blood was maintained for 3 months. Laboratory experiments on HBV-transfected HepG2.2.15 cells affirmed the animal results and the critical role of docosanol in the sustained NM1TFV antiviral responses. These results provide clear "proof of concept" toward an emerging therapeutic paradigm for the treatment and prevention of HBV infection.

CROI 2022: advances in antiviral therapy for HIV, COVID-19, and viral hepatitis

The 2022 Conference on Retroviruses and Opportunistic Infections provided a rich source of new data and comprehensive reviews on antiviral therapy. For COVID-19, intramuscular sotrovimab was noninferior to intravenous sotrovimab, serostatus did not predict the efficacy of sotrovimab, and molnupiravir appeared safe and modestly effective in decreasing hospitalization rates. Trials from low- and middle-income countries provided data to support transitioning those on first-line therapy with or without virologic suppression and those virologically suppressed on second-line therapy to dolutegravir-based regimens. Additional data supported the use of lenacapavir as a long-acting antiretroviral drug. Data across the United States demonstrate the negative impact of the COVID-19 pandemic on the HIV care continuum, although enhanced outreach efforts and decentralization of antiretroviral therapy delivery were associated with improvements in care engagement outcomes. Researchers described potential mechanisms for the emergence of integrase strand transfer inhibitor resistance. Studies on proviral genotyping high-lighted the limitations of its use in predicting clinically significant resistance. Several studies looked at the epidemiology and treatment of hepatitis C and B and the status of current hepatitis C virus elimination efforts. Data presented on HIV, COVID-19, and maternal and pediatric health included 2-year virologic outcome data of very early antiretroviral therapy in potentially reducing the latent HIV reservoir in infants with HIV. Data presented on COVID-19 and HIV therapeutics in children included SARS-CoV-2-neutralizing monoclonal antibodies in children younger than 12 years of age, remdesivir in hospitalized infants and children, and long-acting therapies for HIV treatment in children.

Modeling the population-level impact of treatment on COVID-19 disease and SARS-CoV-2 transmission

Different COVID-19 treatment candidates are under development, and some are becoming available including two promising drugs from Merck and Pfizer. This study provides conceptual frameworks for the effects of three types of treatments, both therapeutic and prophylactic, and to investigate their population-level impact, to inform drug development, licensure, decision-making, and implementation. Different drug efficacies were assessed using an age-structured mathematical model describing SARS-CoV-2 transmission and disease progression, with application to the United States as an illustrative example. Severe and critical infection treatment reduces progression to COVID-19 severe and critical disease and death with small number of treatments needed to avert one disease or death. Post-exposure prophylaxis treatment had a large impact on flattening the epidemic curve, with large reductions in infection, disease, and death, but the impact was strongly age dependent. Pre-exposure prophylaxis treatment had the best impact and effectiveness, with immense reductions in infection, disease, and death, driven by the robust control of infection transmission. Effectiveness of both pre-exposure and post-exposure prophylaxis treatments was disproportionally larger when a larger segment of the population was targeted than a specific age group. Additional downstream potential effects of treatment, beyond the primary outcome, enhance the population-level impact of both treatments. COVID-19 treatments are an important modality in controlling SARS-CoV-2 disease burden. Different types of treatment act synergistically for a larger impact, for these treatments and vaccination.

Incident Hepatitis B Virus Infection in HIV-Infected and HIV-Uninfected Men Who Have Sex With Men From Pre-HAART to HAART Periods: A Cohort Study

BACKGROUND

Men who have sex with men (MSM) are at high risk for hepatitis B virus (HBV) infection. Data on the effect of highly active antiretroviral therapy (HAART) on incident HBV infection in HIV-infected and HIV-uninfected MSM are limited.

OBJECTIVE

To determine predictors of incident HBV infection in MSM during pre-HAART and HAART periods.

DESIGN

Observational cohort study.

SETTING

Cohort of MSM who have, or are at risk for, HIV infection.

PATIENTS

2375 HBV-uninfected MSM in the Multicenter AIDS Cohort Study.

MEASUREMENTS

Poisson regression was used to compare incidence rates of HBV infection in the pre-HAART and HAART eras and to identify factors associated with incidence of HBV infection.

RESULTS

In 25,322 person-years of follow-up, 244 incident HBV infections occurred. The unadjusted incidence rate was higher in HIV-infected MSM than in HIV-uninfected MSM (incidence rate ratio [IRR], 1.9 [95% CI, 1.5 to 2.4]) and was significantly lower in the HAART era than in the pre-HAART era among HIV-infected (IRR, 0.2 [CI, 0.1 to 0.4]) and HIV-uninfected (IRR, 0.3 [CI, 0.2 to 0.4]) MSM. Age younger than 40 years (IRR, 2.3 [CI, 1.7 to 3.0]), more than 1 recent sexual partner (IRR, 3.1 [CI, 2.3 to 4.2]), and HIV infection (IRR, 2.4 [CI, 1.8 to 3.1]) were independently associated with higher incidence of HBV infection, whereas HBV vaccination was protective (IRR, 0.3 [CI, 0.2 to 0.4]). Highly active antiretroviral therapy with HIV RNA levels less than 400 copies/mL was associated with protection (IRR, 0.2 [CI, 0.1 to 0.5]), but HAART in those with HIV RNA levels of 400 copies/mL or greater was not.

LIMITATION

The observational nature limits inferences about causality.

CONCLUSION

Effective HAART is associated with lower incidence of HBV infection; however, even in the HAART era, incidence of HBV infection remains high among MSM.

PRIMARY FUNDING SOURCE

National Institute of Allergy and Infectious Diseases.