Pegylated IFN-alpha2b plus ribavirin for treatment-naive patients coinfected with HCV and HIV

Highlights of the Structure-Activity Relationships of Benzimidazole Linked Pyrrolidines Leading to the Discovery of the Hepatitis C Virus NS5A Inhibitor Pibrentasvir (ABT-530)

Curative interferon and ribavirin sparing treatments for hepatitis C virus (HCV)-infected patients require a combination of mechanistically orthogonal direct acting antivirals. A shared component of these treatments is usually an HCV NS5A inhibitor. First generation FDA approved treatments, including the component NS5A inhibitors, do not exhibit equivalent efficacy against HCV virus genotypes 1-6. In particular, these first generation NS5A inhibitors tend to select for viral drug resistance. Ombitasvir is a first generation HCV NS5A inhibitor included as a key component of Viekira Pak for the treatment of patients with HCV genotype 1 infection. Since the launch of next generation HCV treatments, functional cure for genotype 1-6 HCV infections has been achieved, as well as shortened treatment duration across a wider spectrum of genotypes. In this paper, we show how we have modified the anchor, linker, and end-cap architecture of our NS5A inhibitor design template to discover a next generation NS5A inhibitor pibrentasvir (ABT-530), which exhibits potent inhibition of the replication of wild-type genotype 1-6 HCV replicons, as well as improved activity against replicon variants demonstrating resistance against first generation NS5A inhibitors.

Proteome-wide anti-hepatitis C virus (HCV) and anti-HIV antibody profiling for predicting and monitoring the response to HCV therapy in HIV-coinfected patients

We quantified antibody responses to the hepatitis C virus (HCV) proteome that are associated with sustained virologic response (SVR) in human immunodeficiency virus (HIV)/HCV-coinfected patients treated with pegylated interferon and ribavirin. Analysis of pre- and posttreatment samples revealed significant decreases in the combined anti-core, anti-E1, and anti-NS4 HCV antibody titers in those with SVRs but not in those who experienced relapse or who did not respond. Furthermore, anti-HIV p24 antibody titers inversely correlated with treatment response. These results suggest that profiling anti-HCV antibody is useful for monitoring HCV therapy, especially in discriminating between those who experience relapse and those who have SVRs at 48 weeks.

HIV/Hepatitis C virus-coinfected virologic responders to pegylated interferon and ribavirin therapy more frequently incur interferon-related adverse events than nonresponders do

BACKGROUND

This study aimed to assess the relationship between interferon (IFN)-related adverse effects and Hepatitis C virus (HCV) virologic response in HIV/HCV-coinfected individuals treated with pegylated interferon and ribavirin.

METHODS

We conducted 2 prospective, open-label trials treating HIV/HCV-coinfected individuals with pegylated interferon alpha-2b or alpha-2a and ribavirin for 48 weeks. Safety laboratories, HCV RNA, psychiatric, and ophthalmologic evaluations were performed at baseline and monthly until week 72.

RESULTS

Responders were defined as those with HCV RNA decline of > or = 2-log drop from baseline and nonresponders were those who did not. Remarkably, of the 27 patients (50%) who developed psychiatric toxicities, 26 patients were responders, although only 1 of 14 virologic nonresponders experienced psychiatric toxicity. Other adverse effects, such as anemia and ophthalmologic toxicities, were also more frequent in responders compared with nonresponders. Decline in CD4 T-cell counts strongly correlated with HCV viral decline.

CONCLUSIONS

Our study demonstrates coupling of antiviral effect and occurrence of adverse events in HIV/HCV-coinfected patients. These patients with IFN-related adverse effects need a multidisciplinary treatment approach, hence, they are more likely to achieve sustained virologic response. Future studies are needed to evaluate the factors that predict the development of IFN-alpha-dependent adverse events before therapy.

Pathogenesis of 1918 pandemic and H5N1 influenza virus infections in a guinea pig model: antiviral potential of exogenous alpha interferon to reduce virus shedding

Although highly pathogenic avian influenza H5N1 viruses have yet to acquire the ability to transmit efficiently among humans, the increasing genetic diversity among these viruses and continued outbreaks in avian species underscore the need for more effective measures for the control and prevention of human H5N1 virus infection. Additional small animal models with which therapeutic approaches against virulent influenza viruses can be evaluated are needed. In this study, we used the guinea pig model to evaluate the relative virulence of selected avian and human influenza A viruses. We demonstrate that guinea pigs can be infected with avian and human influenza viruses, resulting in high titers of virus shedding in nasal washes for up to 5 days postinoculation (p.i.) and in lung tissue of inoculated animals. However, other physiologic indicators typically associated with virulent influenza virus strains were absent in this species. We evaluated the ability of intranasal treatment with human alpha interferon (alpha-IFN) to reduce lung and nasal wash titers in guinea pigs challenged with the reconstructed 1918 pandemic H1N1 virus or a contemporary H5N1 virus. IFN treatment initiated 1 day prior to challenge significantly reduced or prevented infection of guinea pigs by both viruses, as measured by virus titer determination and seroconversion. The expression of the antiviral Mx protein in lung tissue correlated with the reduction of virus titers. We propose that the guinea pig may serve as a useful small animal model for testing the efficacy of antiviral compounds and that alpha-IFN treatment may be a useful antiviral strategy against highly virulent strains with pandemic potential.