Safety and efficacy of combination therapy with peginterferon alfa-2a (40kD) and ribavirin in the outpatient setting: prospective analysis of 197 patients with chronic hepatitis C viral infection

Synergistic antiviral activity of Sofosbuvir and type-I interferons (α and β) against Zika virus

Zika virus (ZIKV) is transmitted by mosquitoes and causes Dengue-like illness, neurological symptoms such as Guillain-Barré Syndrome and microcephaly in children born to infected pregnant mothers. Recently, the World Health Organization (WHO) declared ZIKV infection as a Global Health Emergency. However, there are no known prophylactic or therapeutic measures against this virus. As a proof of concept toward combination therapeutic strategy against ZIKV, combinations of host-targeted (Interferon-α and Interferon-β) and direct acting (Sofosbuvir) antivirals were evaluated in a hepatic cell line (Huh7) using a Cytoprotection (CP) assay. The combination of these antivirals resulted in synergistic inhibition of ZIKV infection in the in vitro CP assay. Additional testing in a ZIKV yield assay demonstrated that combination treatment of these antivirals conferred >2-log reduction in the release of viral RNA. Measurement of ZIKV proteins in the cells infected with multiple ZIKV strains isolated from different geographical regions (Americas, Asia, and Africa) using an immunofluorescence assay confirmed the effective antiviral activity of this combination against ZIKV. These results demonstrate the in vitro proof of concept (POC) for using a combination approach utilizing the strengths of both virus and host-targeted antivirals. These results suggest the effectiveness of the combination strategy in combating ZIKV, in the in vitro systems. Further evaluation of such combination therapies in vivo might provide an impetus for the development of effective ZIKV therapeutic strategies.

Ribavirin and boceprevir are able to reduce Canine distemper virus growth in vitro

Canine distemper virus (CDV) is a major infectious disease of dogs. Although vaccines were successful to control CDV spread in canine population, the disease is still common and may pose a threat to unvaccinated dogs. In the attempt to develop specific anti-viral therapeutic tools, the efficacy of several molecules against CDV has been investigated in vitro. In this study the antiviral efficacy in vitro against CDV of ribavirin and boceprevir alone or in combination was evaluated. CDV growth in VERO cells was inhibited by ribavirin, by boceprevir and by a combination of the two molecules at non-cytotoxic concentrations, as evaluated by end-point viral titration in cell monolayers and by quantification of viral RNA using quantitative RT-PCR. By end-point titration, a statistically significant reduction in CDV replication was observed only using ribavirin and boceprevir in combination. By quantitative RT-PCR, a significant reduction of viral growth was observed either in cells treated with ribavirin or boceprevir or with both the two molecules. The association of ribavirin or boceprevir was able to decrease CDV growth by up to 3.4458 logs with respect to untreated infected cells, chiefly at the highest virus dilutions. The results obtained in this study may constitute an important basis for the development of CDV therapies.

Prediction of Sustained Virological Response to Peginterferon-based Therapy for Chronic Hepatitis C: Regression Analysis of a Cohort from Rio Grande do Sul, Brazil

Aim:

Peginterferon plus ribavirin (peg-IFN/RBV) is still the standard of care for treatment of hepatitis C virus (HCV) in many countries. Given the high toxicity of this regimen, our study aimed to develop a prediction tool that can identify which patients are unlikely to benefit from peg-IFN/RBV and could thus postpone treatment in favor of new-generation direct-acting antivirals.

Materials and methods:

Binary regression was performed using demographic, clinical, and laboratory covariates and sustained virological response (SVR) outcomes from a prospective cohort of individuals referred for therapy from 2003 to 2008 in a public HCV treatment center in Rio Grande do Sul, Brazil.

Results:

Of the 743 participants analyzed, 489 completed 48 weeks of treatment (65.8%). A total of 202 of those who completed peg-IFN/RBV therapy achieved SVR (27.2% responders), 196 did not (26.4%), and 91 had missing viral load (VL) at week 72 (12.2% loss to follow-up). The remainder discontinued therapy (n = 254 [34.2%]), 78 (30.7%) doing so due to adverse effects. Baseline covariates included in the regression model were sex, age, human immunodeficiency virus, infection status, aspartate transaminase, alanine transaminase, hemoglobin, platelets, serum creatinine, prothrombin time, pretreatment VL, cirrhosis on liver biopsy, and treatment naivety. A predicted SVR of 17.9% had 90.0% sensitivity for detecting true nonresponders. The negative likelihood ratio at a predicted SVR of 17.9% was 0.16, and the negative predictive value was 92.6%.

Conclusion:

Easily obtainable variables can identify patients that will likely not benefit from peg-IFN-based therapy. This prediction model might be useful to clinicians.

Clinical significance:

To our knowledge, this is the only prediction tool that can reliably help clinicians to postpone peg-IFN/RBV therapy for HCV genotype 1 patients.

How to cite this article: Picon RV, Fendt L, Amaral K, Picon PD. Prediction of Sustained Virological Response to Peginterferon-based Therapy for Chronic Hepatitis C: Regression Analysis of a Cohort from Rio Grande do Sul, Brazil. Euroasian J Hepato-Gastroenterol 2017;7(1):27-33.

Interferon for interferon nonresponding and relapsing patients with chronic hepatitis C

BACKGROUND

The widely-accepted treatment outcome for chronic hepatitis C is the sustained viral response (that is, no measurable viral RNA in blood six months after treatment). However, this surrogate outcome (as well as the previously employed biochemical and histologic ones) has never been validated. This situation exists because there are very few randomized clinical trials that have used clinical events (mortality or manifestations of decompensated cirrhosis) as outcomes, because those clinical events only occur after many years of infection. Patients in whom initial therapy fails to produce sustained viral responses do become potential candidates for retreatment; some of these individuals are not candidates for ribavirin or protease inhibitors and consideration could be given to retreatment with interferon alone.

OBJECTIVES

To assess the benefits and harms of interferon monotherapy retreatment in chronic hepatitis C patients and to validate the currently employed surrogate outcomes in this group of patients.

SEARCH METHODS

We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, and Science Citation Index Expanded until 16 August 2012.

SELECTION CRITERIA

Randomized trials comparing interferon versus placebo or no treatment in chronic hepatitis C nonresponders and relapsers to previous interferon.

DATA COLLECTION AND ANALYSIS

The primary outcomes were mortality (all-cause and hepatic), quality of life, and adverse events. Secondary outcomes were liver-related morbidity, sustained viral responses, biochemical responses, histologic improvements, and costs. We used both fixed-effect and random-effects model meta-analyses, reporting only the former if no difference existed.

MAIN RESULTS

Seven trials were identified. Two of them were at low risk of bias (the HALT-C and EPIC3 trials) and included 1676 patients. Both of these trials addressed the role of long-term low-dose pegylated interferon therapy in patients with severe fibrosis (demonstrated on liver biopsy) and were designed to assess the clinical outcomes. The remaining five trials included 300 patients and were at high risk of bias. Based on all trials reporting the outcomes, no significant difference was observed in either all-cause mortality (78/843 (9.3%) versus 62/867 (7.2%); risk ratio (RR) 1.30, 95% confidence interval (CI) 0.95 to 1.79; 3 trials) or hepatic mortality (41/532 (7.7%) versus 40/552 (7.2%); RR 1.07, 95% CI 0.70 to 1.63; 2 trials); however, when only the two trials at low risk of bias were combined, all-cause mortality was significantly higher in the recipients of the pegylated interferon (78/828 (9.4%) versus 57/848 (6.7%); RR 1.41, 95% CI 1.02 to 1.96) although trial sequential analysis could not exclude the possibility of random error. There was less variceal bleeding in the recipients of the interferon (4/843 (0.5%) versus 18/867 (2.1%); RR 0.24, 95% CI 0.09 to 0.67; 3 trials), although again trial sequential analysis could not exclude the presence of a type I error and the effect could not be confirmed in a random-effects model meta-analysis. No significant differences were seen with regard to the development of ascites, encephalopathy, hepatocellular carcinoma, or the need for liver transplantation. One trial reported quality of life data; the pain score was significantly worse in the recipients of the pegylated interferon. Adverse effects tended to be more common in the interferon recipients; the ones that were significantly more common included hematologic complications, infections, flu-like symptoms, and rash. The recipients of interferon had significantly more sustained viral responses (20/557 (3.6%) versus 1/579 (0.2%); RR 15.38, 95% CI 2.93 to 80.71; 4 trials) and a type I error was excluded by trial sequential analysis. The METAVIR activity score also improved (36/55 (65%) versus 20/46 (43.5%); RR 1.49, 95% CI 1.02 to 2.18; 2 trials). No significant differences were seen with regard to histologic fibrosis assessments.

AUTHORS' CONCLUSIONS

The clinical data were limited to patients with histologic evidence of severe fibrosis who were retreated with pegylated interferon. In this scenario, retreatment with interferon did not appear to provide significant clinical benefit and, when only the trials at low risk of bias were considered, retreatment for several years may even have increased all-cause mortality. Such treatment also produced adverse events. On the other hand, the treatment did result in improvement in some surrogate outcomes, namely sustained viral responses and histologic evidence of inflammation. Interferon monotherapy retreatment cannot be recommended for these patients. No clinical data are available for patients with less severe fibrosis. The sustained viral response cannot be used as a surrogate marker for hepatitis C treatment in this clinical setting with low sustained viral response rates and needs to be validated in others in which higher sustained viral response rates are reported.

Evaluation of pharmacokinetics, user handling, and tolerability of peginterferon alfa-2a (40 kDa) delivered via a disposable autoinjector device

BACKGROUND

Peginterferon alfa-2a (40 kDa) is currently administered using a prefilled syringe. The peginterferon alfa-2a disposable autoinjector is a new safety-engineered device designed to facilitate injection and reduce the risk of needlestick injuries. The analysis of two open-label Phase I trials evaluated the pharmacokinetics, successful administration, and tolerability of peginterferon alfa-2a when using the autoinjector. The studies were performed to support the filing and registration of the autoinjector device.

METHODS

In trial 1, 50 healthy adult subjects received one 180 μg dose of peginterferon alfa-2a via the autoinjector. Serial blood samples were collected predose, up to 336 hours following drug administration, and at follow-up (28 ± 3 days post-dosing) for noncompartmental pharmacokinetic analysis. Trial 2 randomized 60 adult patients with chronic hepatitis C to 180 μg peginterferon alfa-2a once weekly by the autoinjector or prefilled syringe for 3 weeks followed by the alternative device (prefilled syringe or autoinjector, respectively) for 3 weeks. Patients also received ribavirin. Administration by the devices was evaluated under direct observation by a study staff member and by patient subjective assessment.

RESULTS

In trial 1, following a single dose of peginterferon alfa-2a, the maximum plasma concentration was 16.1 ± 5.3 ng/mL (mean ± standard deviation), and area under the concentration time curve (0-168 hours) was 1996 ± 613 ng · hour/mL, similar to that reported using a vial/syringe or prefilled syringe. In trial 2, few patients showed handling difficulties with either device. Generally, patients were observed to be more satisfied and confident, followed instructions better, and successfully initiated injection with the autoinjector versus the prefilled syringe. Patients reported the autoinjector to be more convenient and easier to use. No pain or discomfort was experienced using the autoinjector. The autoinjector safety profile was consistent with that known for peginterferon alfa-2a/ribavirin.

CONCLUSION

These results indicate that peginterferon alfa-2a can be successfully and safely delivered via the autoinjector and that the device is easy to handle.

Side effects of the therapy with peginterferon and ribavirin in chronic hepatitis C: a small audit

This study sought to decribe, quantify, and classify any adverse reactions occurring in patients with chronic hepatitis C treated with peginterferon and ribavirin, as well as verify the occurrence of potential medication interactions. The most prevalent reactions were fatigue (84.8%), fever (83%), weight loss (80%), irritability (74%), and body pain (72%). Most of the reactions were classified as mild (95%), whereas 4.5% were classified as moderate and 0.4% as severe. Adverse reactions led to the rearrangement of therapy for 9 patients (20%), where there was a reduction in dose for 7 (15%), temporary interruption of treatment for 5 (11%), and permanent discontinuation for 3 patients (7%). A total of 11 potential medication interactions were identified in 9 patients (20%), with the most frequent between peginterferon-α2a and captopril (45%). Given the above, it is observed that the treatment of chronic hepatitis C is marked by several adverse reactions of varying severity, which can interfere with the patient's quality of life or in treatment compliance, and that can be aggravated by potential drug-drug interactions.

A French prospective observational study of the treatment of chronic hepatitis C in drug abusers

The objective of this prospective, multicenter, observational study was to evaluate healthcare for hepatitis C virus (HCV)-infected drug abusers in France and to determine predictors of successful therapeutic intervention. A total of 170 drug users were recruited from 40 French centers. Three centers recruited 66 participants (38.8%), and one to eight patients each were enrolled from 37 other centers (n=104). A sustained viral response (SVR) was seen in 65 (38.2%) patients. SVR rates were significantly higher in compliant than in non-compliant patients (43.5% versus 23.9%; P=0.019), in patients from high- rather than low-recruiting centers (54.5% versus 27.9%; P<0.001) and in patients receiving Buprenorphine rather than methadone (48.1% versus 21.8%; P=0.001). In patients, who completed both the treatment and follow-up (n=94), SVR rate was 57.4%. Buprenorphine substitution therapy and genotypes 2 or 3 HCV infection were associated with significantly higher rates of SVR (P<0.01, for both comparisons). In conclusion, successful care of hepatitis requires an active treatment policy of every center toward drug addicts. Additional studies are needed to explore the difference in SVR with methadone versus Buprenorphine therapy.

[Results of pegylated interferon and ribavirin for the treatment of chronic hepatitis C in clinical practice: a 5-year experience]

INTRODUCTION

Numerous clinical trials have demonstrated the efficacy of treatment with pegylated interferon and ribavirin but little is known about the results obtained in clinical practice.

OBJECTIVE

To evaluate treatment response and factors influencing the treatment of chronic hepatitis C in clinical practice.

MATERIAL AND METHODS

Between August 2001 and December 2005, we treated 219 patients with pegylated interferon (alpha 2a -fixed dose, or alpha 2b, according to weight) and ribavirin. Patients with genotype 1 or 4 received treatment with pegylated interferon alpha 2a (180 microg/week) and ribavirin (1000 mg/day if body weight was <75 kg or 1200 mg/day if body weight was >75 kg) or interferon alpha 2b (1.5 microg/kg/week) and ribavirin (10.6 mg/kg/day) for 48 weeks. Patients with genotype 2 or 3 were treated for 24 weeks with the same regimen of pegylated interferon alpha-2a or alpha-2b, but with 800 mg of ribavirin divided in two daily doses. Sustained viral response was defined as absence of HCV-RNA 6 months after the end of treatment.

RESULTS

A total of 219 patients were included (69% men; mean age 44+/-10). As epidemiological antecedents, 22.4% of the treated patients had previously consumed drugs parenterally and 22.4% had received blood transfusions before 1992. Forty-seven percent of the patients with liver biopsy had fibrosis bridges or established liver cirrhosis. The genotype was distributed as follows: 69.8% genotype 1, 4.1% genotype 2, 17.8% genotype 3, and 8.2% genotype 4. Of the 219 patients, 76 (35%) were treated with pegylated interferon alpha 2a and 143 (65%) with interferon alpha 2b. Analysis of response by genotype revealed that sustained viral response was obtained in 46% genotype 1, 88.9% genotype 2, 78.9% genotype 3, and 33.3% genotype 4. Univariate analysis showed that the only variable influencing sustained viral response was genotype.

CONCLUSION

Treatment with pegylated interferon and ribavirin in clinical practice shows a similar pattern of sustained viral response to that obtained in clinical research. The main variable correlated with sustained viral response continues to be viral genotype.

In vitro efficacy of ribavirin against canine distemper virus

Despite vaccination, canine distemper virus (CDV) remains one of the important pathogen of dogs with worldwide distribution. Ribavirin (RIB) inhibits replication of measles virus (MV), a morbillivirus closely related to CDV, both in vitro and in vivo. In this report the antiviral activity of RIB against CDV in cell cultures was assessed. Quantitative real-time RT-PCR was used to measure viral RNA in VERO cells infected by CDV and to evaluate the inhibitory effects of RIB. RIB caused a dose- and time-dependent decrease in accumulation of CDV RNA when added after virus adsorption. RIB was highly effective in preventing CDV replication at low concentrations with 50% virus-inhibitory concentrations ranging from 0.02 to 0.05 mM. Such low values were comparable to values displayed by highly susceptible strains of MV. In addition, CDV was passaged sequentially in VERO cell monolayers in the presence of RIB to trigger viral extinction. The virus was no longer detected after three passages, suggesting that error catastrophe is one of the modes of action of RIB against CDV. These findings suggest RIB as a promising tool for the therapy of CD in dogs.