Ribavirin monotherapy for chronic hepatitis C

Utilization, reimbursement, and price trends for Hepatitis C virus medications in the US Medicaid programs: 2001-2021

Background

Hepatitis C Virus (HCV) remains a challenging health problem worldwide, with increasing incidence despite being curable with Direct Acting Antiviral (DAA) agents.

Objective

This study aimed to describe the utilization, reimbursement, and price trends of HCV treatments and evaluate the influence of treatment guidelines and policies.

Methods

A retrospective, descriptive drug utilization study conducted using the outpatient pharmacy data extracted from the Centers for Medicaid and Medicare Services State Drug Utilization Data between 2001 and 2021. All HCV treatments approved in the US were included, conventional therapy (CT), and DAA agents. The annual secular trends were calculated for each medication's total number of prescriptions, reimbursements, and prices. The average reimbursement per prescription was calculated and utilized as a proxy of prices. The HCV treatment guideline and policies and legislation were evaluated overtime to measure the impact on the trends.

Results

Despite CT having a higher total utilization, DAA agents commanded significantly greater reimbursements, with 4.1 billion USD for CT and 19.45 billion USD for DAA agents. CT utilization increased rapidly and dominated the market until 2011, peaking at 379,696 prescriptions in 2003 but declining afterward. DAA agents' utilization increased rapidly in their first year: i.e., sofosbuvir reached 50,377 prescriptions with 1.3 billion USD in 2014, while ledipasvir/sofosbuvir reached 79,387 prescriptions with 2 billion USD in 2015. The average price per prescription was high for the DAA agents, like 24,992 USD for sofosbuvir and 22,787 USD for ledipasvir/sofosbuvir, compared to CT medications ribavirin, around 500 USD, and pegINF, around 3000 USD. The new DAA agents replaced CT, and initiating market competition among DAA agents.

Conclusion

The introduction of multiple DAA agents slightly changed their prescription prices but remained high during the study period. The recent increase in HCV incidence cases indicates accessibility issues for costly and effective DAA agents, with treatment guidelines and policies playing a critical role in shaping these trends.

Therapeutic targeting of measles virus polymerase with ERDRP-0519 suppresses all RNA synthesis activity

Morbilliviruses, such as measles virus (MeV) and canine distemper virus (CDV), are highly infectious members of the paramyxovirus family. MeV is responsible for major morbidity and mortality in non-vaccinated populations. ERDRP-0519, a pan-morbillivirus small molecule inhibitor for the treatment of measles, targets the morbillivirus RNA-dependent RNA-polymerase (RdRP) complex and displayed unparalleled oral efficacy against lethal infection of ferrets with CDV, an established surrogate model for human measles. Resistance profiling identified the L subunit of the RdRP, which harbors all enzymatic activity of the polymerase complex, as the molecular target of inhibition. Here, we examined binding characteristics, physical docking site, and the molecular mechanism of action of ERDRP-0519 through label-free biolayer interferometry, photoaffinity cross-linking, and in vitro RdRP assays using purified MeV RdRP complexes and synthetic templates. Results demonstrate that unlike all other mononegavirus small molecule inhibitors identified to date, ERDRP-0519 inhibits all phosphodiester bond formation in both de novo initiation of RNA synthesis at the promoter and RNA elongation by a committed polymerase complex. Photocrosslinking and resistance profiling-informed ligand docking revealed that this unprecedented mechanism of action of ERDRP-0519 is due to simultaneous engagement of the L protein polyribonucleotidyl transferase (PRNTase)-like domain and the flexible intrusion loop by the compound, pharmacologically locking the polymerase in pre-initiation conformation. This study informs selection of ERDRP-0519 as clinical candidate for measles therapy and identifies a previously unrecognized druggable site in mononegavirus L polymerase proteins that can silence all synthesis of viral RNA.

The mononegavirus order contains major established and recently emerged human pathogens. Despite the threat to human health, antiviral therapeutics directed against this order remain understudied. The mononegavirus polymerase complex represents a promising drug target due to its central importance for both virus replication and viral mitigation of the innate host antiviral response. In this study, we have mechanistically characterized a clinical candidate small-molecule MeV polymerase inhibitor. The compound blocked all phosphodiester bond formation activity, a unique mechanism of action unlike all other known mononegavirus polymerase inhibitors. Photocrosslinking-based target site mapping demonstrated that this class-defining prototype inhibitor stabilizes a pre-initiation conformation of the viral polymerase complex that sterically cannot accommodate template RNA. Function-equivalent druggable sites exist in all mononegavirus polymerases. In addition to its direct anti-MeV impact, the insight gained in this study can therefore serve as a blueprint for indication spectrum expansion through structure-informed scaffold engineering or targeted drug discovery.

Prevalence of Hepatitis C virus genotypes in nine selected European countries: A systematic review

BACKGROUND

Hepatitis C virus (HCV) infection is a global health problem especially for its increasing level of mortality. Detailed knowledge of HCV genotypes prevalence has clinical relevance since the efficacy of therapies is impacted by genotypes and subtypes distribution. Moreover, HCV exhibits a great genetic variability regionally. To date, there are no published studies assessing HCV genotypes distribution in specific countries of the Mediterranean basin. The aim of this study was to review data published from 2000 to 2017 with the purpose to estimate genotypes distribution of HCV infection in nine European countries all located in the Mediterranean basin.

METHODS

A systematic research of peer-reviewed journals indexed in PubMed, Scopus, and EMBASE databases selected if containing data regarding distribution of HCV genotypes in nine selected European countries (Albania, Bosnia, Croatia, France, Greece, Italy, Montenegro, Slovenia, and Spain) was performed.

RESULTS

Genotype 1 is the most common (61.0%), ranging from 80.0% in Croatia to 46.0% in Greece, followed by genotype 3 (20.0%), varying from 38.0% in Slovenia to 7.0% and 8.0%, respectively, in Italy and in Albania and by genotype 4 (10.0%) that shows an increase of 1.1% with respect to data obtained till 2014 probably due to the increasing migrants arrivals to Southern Europe. G2, the fourth most frequent genotype (8.5%), particularly common in Italy (27.0%) and Albania (18.0%) might be probably introduced in Southern Italy as a result of Albanian campaign during Second World War and more and more increased by the migration flows from Albania to Italy in the 90s.

CONCLUSION

Epidemiology of HCV infection shows a high variability across the European countries that border the Mediterranean Sea. HCV genotyping is a relevant tool to monitor the dynamic process influenced by both evolving transmission trends and new migration flows on HCV scenario.

Prevalence of Hepatitis C virus genotypes in nine selected European countries: A systematic review

BACKGROUND

Hepatitis C virus (HCV) infection is a global health problem especially for its increasing level of mortality. Detailed knowledge of HCV genotypes prevalence has clinical relevance since the efficacy of therapies is impacted by genotypes and subtypes distribution. Moreover, HCV exhibits a great genetic variability regionally. To date, there are no published studies assessing HCV genotypes distribution in specific countries of the Mediterranean basin. The aim of this study was to review data published from 2000 to 2017 with the purpose to estimate genotypes distribution of HCV infection in nine European countries all located in the Mediterranean basin.

METHODS

A systematic research of peer-reviewed journals indexed in PubMed, Scopus, and EMBASE databases selected if containing data regarding distribution of HCV genotypes in nine selected European countries (Albania, Bosnia, Croatia, France, Greece, Italy, Montenegro, Slovenia, and Spain) was performed.

RESULTS

Genotype 1 is the most common (61.0%), ranging from 80.0% in Croatia to 46.0% in Greece, followed by genotype 3 (20.0%), varying from 38.0% in Slovenia to 7.0% and 8.0%, respectively, in Italy and in Albania and by genotype 4 (10.0%) that shows an increase of 1.1% with respect to data obtained till 2014 probably due to the increasing migrants arrivals to Southern Europe. G2, the fourth most frequent genotype (8.5%), particularly common in Italy (27.0%) and Albania (18.0%) might be probably introduced in Southern Italy as a result of Albanian campaign during Second World War and more and more increased by the migration flows from Albania to Italy in the 90s.

CONCLUSION

Epidemiology of HCV infection shows a high variability across the European countries that border the Mediterranean Sea. HCV genotyping is a relevant tool to monitor the dynamic process influenced by both evolving transmission trends and new migration flows on HCV scenario.

Ribavirin for treating Crimean Congo haemorrhagic fever

BACKGROUND

Crimean Congo haemorrhagic fever (CCHF) is a tick-borne disease that occurs in parts of Asia, Europe and Africa. Since 2000 the infection has caused epidemics in Turkey, Iran, Russia, Uganda and Pakistan. Good-quality general supportive medical care helps reduce mortality. There is uncertainty and controversy about treating CCHF with the antiviral drug ribavirin.

OBJECTIVES

To assess the effects of ribavirin for treating people with Crimean Congo haemorrhagic fever.

SEARCH METHODS

We searched the Cochrane Infectious Diseases Group Specialized Register; the Central Register of Controlled Trials (CENTRAL); MEDLINE (PubMed); Embase (OVID); Science Citation Index-Expanded, Social Sciences Citation index, conference proceedings (Web of Science); and CINAHL (EBSCOHost). We also searched the WHO International Clinical Trials Registry Platform (ICTRP) and ClinicalTrials.gov for trials in progress. We conducted all searches up to 16 October 2017. We also contacted experts in the field and obtained further studies from these sources.

SELECTION CRITERIA

We evaluated studies assessing the use of ribavirin in people with suspected or confirmed Crimean Congo haemorrhagic fever. We included randomised control trials (RCTs); non-randomised studies (NRSs) that included more than 10 participants designed as cohort studies with comparators; and case-control studies.

DATA COLLECTION AND ANALYSIS

Two review authors assessed eligibility, risk of bias, and extracted data. For non-randomized studies we used the ROBINS-I tool to assess risk of bias. The main effects analysis included all studies where we judged the risk of bias to be low, moderate or high. We summarized dichotomous outcomes using risk ratios (RRs) and continuous outcomes using mean differences (MDs), and used meta-analyses where appropriate. We carried out a subsidiary appraisal and analysis of studies with critical risk of bias for the primary outcome, as these are often cited to support using ribavirin.

MAIN RESULTS

For the main effects analysis, five studies met our inclusion criteria: one RCT with 136 participants and four non-randomized studies with 612 participants. We excluded 18 non-randomized studies with critical risk of bias, where none had attempted to control for confounding.We do not know if ribavirin reduces mortality (1 RCT; RR 1.13, 95% confidence interval (CI) 0.29 to 4.32; 136 participants; very low-certainty evidence; 3 non-randomized studies; RR 0.72, 95% CI 0.41 to 1.28; 549 participants; very low-certainty evidence). We do not know if ribavirin reduces the length of stay in hospital (1 RCT: mean difference (MD) 0.70 days, 95% CI -0.39 to 1.79; 136 participants; and 1 non-randomized study: MD -0.80, 95% CI -2.70 to 1.10; 50 participants; very low-certainty evidence). We do not know if it reduces the risk of patients needing platelet transfusions (1 RCT: RR 1.23, 95% CI 0.77 to 1.96; 136 participants; very low-certainty evidence). For adverse effects (including haemolytic anaemia and a need to discontinue treatment), we do not know whether there is an increased risk with ribavirin in people with CCHF as data are insufficient.We do not know if adding ribavirin to early supportive care improves outcomes. One non-randomized study assessed mortality in people receiving ribavirin and supportive care within four days or less from symptom onset compared to after four days since symptom onset: mortality was lower in the group receiving early supportive care and ribavirin, but it is not possible to distinguish between the effects of ribavirin and early supportive medical care alone.In the subsidiary analysis, 18 studies compared people receiving ribavirin with those not receiving ribavirin. All had a critical risk of bias due to confounding, reflected in the mortality point estimates favouring ribavirin.

AUTHORS' CONCLUSIONS

We do not know if ribavirin is effective for treating Crimean Congo haemorrhagic fever. Non-randomized studies are often cited as evidence of an effect, but the risk of bias in these studies is high.

Direct-acting antivirals for chronic hepatitis C

BACKGROUND

Millions of people worldwide suffer from hepatitis C, which can lead to severe liver disease, liver cancer, and death. Direct-acting antivirals (DAAs), e.g. sofosbuvir, are relatively new and expensive interventions for chronic hepatitis C, and preliminary results suggest that DAAs may eradicate hepatitis C virus (HCV) from the blood (sustained virological response). Sustained virological response (SVR) is used by investigators and regulatory agencies as a surrogate outcome for morbidity and mortality, based solely on observational evidence. However, there have been no randomised trials that have validated that usage.

OBJECTIVES

To assess the benefits and harms of DAAs in people with chronic HCV.

SEARCH METHODS

We searched for all published and unpublished trials in The Cochrane Hepato-Biliary Group Controlled Trials Register, CENTRAL, MEDLINE, Embase, Science Citation Index Expanded, LILACS, and BIOSIS; the Chinese Biomedical Literature Database (CBM), China Network Knowledge Information (CNKI), the Chinese Science Journal Database (VIP), Google Scholar, The Turning Research into Practice (TRIP) Database, ClinicalTrials.gov, European Medicines Agency (EMA) (www.ema.europa.eu/ema/), WHO International Clinical Trials Registry Platform (www.who.int/ictrp), the Food and Drug Administration (FDA) (www.fda.gov), and pharmaceutical company sources for ongoing or unpublished trials. Searches were last run in October 2016.

SELECTION CRITERIA

Randomised clinical trials comparing DAAs versus no intervention or placebo, alone or with co-interventions, in adults with chronic HCV. We included trials irrespective of publication type, publication status, and language.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Our primary outcomes were hepatitis C-related morbidity, serious adverse events, and health-related quality of life. Our secondary outcomes were all-cause mortality, ascites, variceal bleeding, hepato-renal syndrome, hepatic encephalopathy, hepatocellular carcinoma, non-serious adverse events (each reported separately), and SVR. We systematically assessed risks of bias, performed Trial Sequential Analysis, and followed an eight-step procedure to assess thresholds for statistical and clinical significance. We evaluated the overall quality of the evidence, using GRADE.

MAIN RESULTS

We included a total of 138 trials randomising a total of 25,232 participants. The trials were generally short-term trials and designed primarily to assess the effect of treatment on SVR. The trials evaluated 51 different DAAs. Of these, 128 trials employed matching placebo in the control group. All included trials were at high risk of bias. Eighty-four trials involved DAAs on the market or under development (13,466 participants). Fifty-seven trials administered DAAs that were discontinued or withdrawn from the market. Study populations were treatment-naive in 95 trials, had been exposed to treatment in 17 trials, and comprised both treatment-naive and treatment-experienced individuals in 24 trials. The HCV genotypes were genotype 1 (119 trials), genotype 2 (eight trials), genotype 3 (six trials), genotype 4 (nine trials), and genotype 6 (one trial). We identified two ongoing trials.We could not reliably determine the effect of DAAs on the market or under development on our primary outcome of hepatitis C-related morbidity or all-cause mortality. There were no data on hepatitis C-related morbidity and only limited data on mortality from 11 trials (DAA 15/2377 (0.63%) versus control 1/617 (0.16%); OR 3.72, 95% CI 0.53 to 26.18, very low-quality evidence). We did not perform Trial Sequential Analysis on this outcome.There is very low quality evidence that DAAs on the market or under development do not influence serious adverse events (DAA 5.2% versus control 5.6%; OR 0.93, 95% CI 0.75 to 1.15 , 15,817 participants, 43 trials). The Trial Sequential Analysis showed that there was sufficient information to rule out that DAAs reduce the relative risk of a serious adverse event by 20% when compared with placebo. The only DAA that showed a lower risk of serious adverse events when meta-analysed separately was simeprevir (OR 0.62, 95% CI 0.45 to 0.86). However, Trial Sequential Analysis showed that there was not enough information to confirm or reject a relative risk reduction of 20%, and when one trial with an extreme result was excluded, the meta-analysis result showed no evidence of a difference.DAAs on the market or under development may reduce the risk of no SVR from 54.1% in untreated people to 23.8% in people treated with DAA (RR 0.44, 95% CI 0.37 to 0.52, 6886 participants, 32 trials, low quality evidence). Trial Sequential Analysis confirmed this meta-analysis result.Only 1/84 trials on the market or under development assessed the effects of DAAs on health-related quality of life (SF-36 mental score and SF-36 physical score).There was insufficient evidence from trials on withdrawn or discontinued DAAs to determine their effect on hepatitis C-related morbidity and all-cause mortality (OR 0.64, 95% CI 0.23 to 1.79; 5 trials, very low-quality evidence). However, these DAAs seemed to increase the risk of serious adverse events (OR 1.45, 95% CI 1.22 to 1.73; 29 trials, very low-quality evidence). Trial Sequential Analysis confirmed this meta-analysis result.None of the 138 trials provided useful data to assess the effects of DAAs on the remaining secondary outcomes (ascites, variceal bleeding, hepato-renal syndrome, hepatic encephalopathy, and hepatocellular carcinoma).

AUTHORS' CONCLUSIONS

The evidence for our main outcomes of interest come from short-term trials, and we are unable to determine the effect of long-term treatment with DAAs. The rates of hepatitis C morbidity and mortality observed in the trials are relatively low and we are uncertain as to how DAAs affect this outcome. Overall, there is very low quality evidence that DAAs on the market or under development do not influence serious adverse events. There is insufficient evidence to judge if DAAs have beneficial or harmful effects on other clinical outcomes for chronic HCV. Simeprevir may have beneficial effects on risk of serious adverse event. In all remaining analyses, we could neither confirm nor reject that DAAs had any clinical effects. DAAs may reduce the number of people with detectable virus in their blood, but we do not have sufficient evidence from randomised trials that enables us to understand how SVR affects long-term clinical outcomes. SVR is still an outcome that needs proper validation in randomised clinical trials.

Direct-acting antivirals for chronic hepatitis C

BACKGROUND

Millions of people worldwide suffer from hepatitis C, which can lead to severe liver disease, liver cancer, and death. Direct-acting antivirals (DAAs) are relatively new and expensive interventions for chronic hepatitis C, and preliminary results suggest that DAAs may eradicate hepatitis C virus (HCV) from the blood (sustained virological response). However, it is still questionable if eradication of hepatitis C virus in the blood eliminates hepatitis C in the body, and improves survival and leads to fewer complications.

OBJECTIVES

To assess the benefits and harms of DAAs in people with chronic HCV.

SEARCH METHODS

We searched for all published and unpublished trials in The Cochrane Hepato-Biliary Group Controlled Trials Register, CENTRAL, MEDLINE, Embase, Science Citation Index Expanded, LILACS, and BIOSIS; the Chinese Biomedical Literature Database (CBM), China Network Knowledge Information (CNKI), the Chinese Science Journal Database (VIP), Google Scholar, The Turning Research into Practice (TRIP) Database, ClinicalTrials.gov, European Medicines Agency (EMA) (www.ema.europa.eu/ema/), WHO International Clinical Trials Registry Platform (www.who.int/ictrp), the Food and Drug Administration (FDA) (www.fda.gov), and pharmaceutical company sources for ongoing or unpublished trials. Searches were last run in October 2016.

SELECTION CRITERIA

Randomised clinical trials comparing DAAs versus no intervention or placebo, alone or with co-interventions, in adults with chronic HCV. We included trials irrespective of publication type, publication status, and language.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Our primary outcomes were hepatitis C-related morbidity, serious adverse events, and quality of life. Our secondary outcomes were all-cause mortality, ascites, variceal bleeding, hepato-renal syndrome, hepatic encephalopathy, hepatocellular carcinoma, non-serious adverse events (each reported separately), and sustained virological response. We systematically assessed risks of bias, performed Trial Sequential Analysis, and followed an eight-step procedure to assess thresholds for statistical and clinical significance. The overall quality of the evidence was evaluated using GRADE.

MAIN RESULTS

We included a total of 138 trials randomising a total of 25,232 participants. The 138 trials assessed the effects of 51 different DAAs. Of these, 128 trials employed matching placebo in the control group. All included trials were at high risk of bias. Eighty-four trials involved DAAs on the market or under development (13,466 participants). Fifty-seven trials administered withdrawn or discontinued DAAs. Trial participants were treatment-naive (95 trials), treatment-experienced (17 trials), or both treatment-naive and treatment-experienced (24 trials). The HCV genotypes were genotype 1 (119 trials), genotype 2 (eight trials), genotype 3 (six trials), genotype 4 (nine trials), and genotype 6 (one trial). We identified two ongoing trials.Meta-analysis of the effects of all DAAs on the market or under development showed no evidence of a difference when assessing hepatitis C-related morbidity or all-cause mortality (OR 3.72, 95% CI 0.53 to 26.18, P = 0.19, I² = 0%, 2,996 participants, 11 trials, very low-quality evidence). As there were no data on hepatitis C-related morbidity and very few data on mortality (DAA 15/2377 (0.63%) versus control 1/617 (0.16%)), it was not possible to perform Trial Sequential Analysis on hepatitis C-related morbidity or all-cause mortality.Meta-analysis of all DAAs on the market or under development showed no evidence of a difference when assessing serious adverse events (OR 0.93, 95% CI 0.75 to 1.15, P = 0.52, I² = 0%, 15,817 participants, 43 trials, very low-quality evidence). The Trial Sequential Analysis showed that the cumulative Z-score crossed the trial sequential boundary for futility, showing that there was sufficient information to rule out that DAAs compared with placebo reduced the relative risk of a serious adverse event by 20%. The only DAA that showed a significant difference on risk of serious adverse events when meta-analysed separately was simeprevir (OR 0.62, 95% CI 0.45 to 0.86). However, Trial Sequential Analysis showed that there was not enough information to confirm or reject a relative risk reduction of 20%, and when one trial with an extreme result was excluded, then the meta-analysis result showed no evidence of a difference.DAAs on the market or under development seemed to reduce the risk of no sustained virological response (RR 0.44, 95% CI 0.37 to 0.52, P < 0.00001, I² = 77%, 6886 participants, 32 trials, very low-quality evidence) and Trial Sequential Analysis confirmed this meta-analysis result.Only 1/84 trials on the market or under development assessed the effects of DAAs on health-related quality of life (SF-36 mental score and SF-36 physical score).Withdrawn or discontinued DAAs had no evidence of a difference when assessing hepatitis C-related morbidity and all-cause mortality (OR 0.64, 95% CI 0.23 to 1.79, P = 0.40, I² = 0%; 5 trials, very low-quality evidence). However, withdrawn DAAs seemed to increase the risk of serious adverse events (OR 1.45, 95% CI 1.22 to 1.73, P = 0.001, I² = 0%, 29 trials, very low-quality evidence), and Trial Sequential Analysis confirmed this meta-analysis result.Most of all outcome results were short-term results; therefore, we could neither confirm nor reject any long-term effects of DAAs. None of the 138 trials provided useful data to assess the effects of DAAs on the remaining secondary outcomes (ascites, variceal bleeding, hepato-renal syndrome, hepatic encephalopathy, and hepatocellular carcinoma).

AUTHORS' CONCLUSIONS

Overall, DAAs on the market or under development do not seem to have any effects on risk of serious adverse events. Simeprevir may have beneficial effects on risk of serious adverse event. In all remaining analyses, we could neither confirm nor reject that DAAs had any clinical effects. DAAs seemed to reduce the risk of no sustained virological response. The clinical relevance of the effects of DAAs on no sustained virological response is questionable, as it is a non-validated surrogate outcome. All trials and outcome results were at high risk of bias, so our results presumably overestimate benefit and underestimate harm. The quality of the evidence was very low.

Ombitasvir plus paritaprevir plus ritonavir with or without ribavirin in treatment-naive and treatment-experienced patients with genotype 4 chronic hepatitis C virus infection (PEARL-I): a randomised, open-label trial

BACKGROUND

Hepatitis C virus (HCV) genotype 4 accounts for about 13% of global HCV infections. Because interferon-containing treatments for genotype 4 infection have low efficacy and poor tolerability, an unmet need exists for effective all-oral regimens. We examined the efficacy and safety of an all-oral interferon-free regimen of ombitasvir, an NS5A inhibitor, and paritaprevir (ABT-450), an NS3/4A protease inhibitor dosed with ritonavir (ombitasvir plus paritaprevir plus ritonavir), given with or without ribavirin.

METHODS

In this multicentre ongoing phase 2b, randomised, open-label combination trial (PEARL-I), patients were recruited from academic, public, and private hospitals and clinics in France, Hungary, Italy, Poland, Romania, Spain, Turkey, and the USA. Eligible participants were aged 18-70 years with non-cirrhotic, chronic HCV genotype 4 infection (documented ≥6 months before screening) and plasma HCV RNA levels higher than 10,000 IU/mL. Previously untreated (treatment-naive) patients were randomly assigned (1:1) by computer-generated randomisation lists to receive once-daily ombitasvir (25 mg) plus paritaprevir (150 mg) plus ritonavir (100 mg) with or without weight-based ribavirin for 12 weeks. Previously treated (treatment-experienced) patients who had received pegylated interferon plus ribavirin all received the ribavirin-containing regimen. The primary endpoint was a sustained virological response (HCV RNA <25 IU/mL) 12 weeks after the end of treatment (SVR12). Analysis was by intention to treat. This study is registered with ClinicalTrials.gov, number NCT01685203.

FINDINGS

Between Aug 14, 2012, and Nov 19, 2013, 467 patients with HCV infection were screened, of whom 174 were infected with genotype 4. 135 patients were randomly assigned to treatment and received at least one dose of study medication; 86 patients were treatment-naive, of whom 44 received ombitasvir plus paritaprevir plus ritonavir and 42 received ombitasvir plus paritaprevir plus ritonavir with ribavirin, and 49 treatment-experienced patients received the ribavirin-containing regimen. In previously untreated patients, SVR12 rates were 100% (42/42 [95% CI 91·6-100]) in the ribavirin-containing regimen and 90·9% (40/44 [95% CI 78·3-97·5]) in the ribavirin-free regimen. No statistically significant differences in SVR12 rates were noted between the treatment-naive groups (mean difference -9·16% [95% CI -19·61 to 1·29]; p=0·086). All treatment-experienced patients achieved SVR12 (49/49; 100% [95% CI 92·7-100]). In the ribavirin-free group, two (5%) of 42 treatment-naive patients had virological relapse, and one (2%) of 44 had virological breakthrough; no virological failures were recorded in the ribavirin-containing regimen. The most common adverse event was headache (14 [29%] of 49 treatment-experienced patients and 14 [33%] of 42 treatment-naive patients). No adverse event-related discontinuations or dose interruptions of study medications, including ribavirin, were noted, and only four patients (4%) of 91 receiving ribavirin required dose modification for haemoglobin less than 100 g/L or anaemia.

INTERPRETATION

An interferon-free regimen of ombitasvir plus paritaprevir plus ritonavir with or without ribavirin achieved high sustained virological response rates at 12 weeks after the end of treatment and was generally well tolerated, with low rates of anaemia and treatment discontinuation in non-cirrhotic previously untreated and previously treated patients with HCV genotype 4 infection.

FUNDING

AbbVie.

Ribavirin induced hemolysis: A novel mechanism of action against chronic hepatitis C virus infection

Hepatitis C virus (HCV) is not usually cleared by our immune system, leading to the development of chronic hepatitis C infection. Chronic HCV induces the production of various cytokines, predominantly by Kupffer cells (KCs), and creates a pro-inflammatory state in the liver. The chronic dysregulated production of interferon (IFN) and other cytokines by KCs also promotes innate immune tolerance. Ribavirin (RBV) monotherapy has been shown to decrease inflammation in liver of patients with chronic hepatitis C. Sustained virological response (SVR) is significantly higher when IFN is combined with RBV in chronic HCV (cHCV) infection. However, the mechanism of their synergy remains unclear. Previous theories have attempted to explain the anti-HCV effect based on direct action of RBV alone on the virus or on the immune system; however, these theories have serious shortcomings. We propose that hemolysis, which universally occurs with RBV therapy and which is considered a limiting side effect, is precisely the mechanism by which the anti-HCV effect is exerted. Passive hemolysis results in anti-inflammatory/antiviral actions within the liver that disrupt the innate immune tolerance, leading to the synergy of RBV with IFN-α. Ribavirin-induced hemolysis floods the hepatocytes and KCs with heme, which is metabolized and detoxified by heme oxygenase-1 (HMOX1) to carbon monoxide (CO), biliverdin and free iron (which induces ferritin). These metabolites of heme possess anti-inflammatory and antioxidant properties. Thus, HMOX1 plays an extremely important anti-oxidant, anti-inflammatory and cytoprotective role, particularly in KCs and hepatocytes. HMOX1 has been noted to have anti-viral effects in hepatitis C infected cell lines. Additionally, it has been shown to enhance the response to IFN-α by restoring interferon-stimulated genes (ISGs). This mechanism can be clinically corroborated by the following observations that have been found in patients undergoing RBV/IFN combination therapy for cHCV: (1) SVR rates are higher in patients who develop anemia; (2) once anemia (due to hemolysis) occurs, the SVR rate does not depend on the treatment utilized to manage anemia; and (3) ribavirin analogs, such as taribavirin and levovirin, which increase intrahepatic ribavirin levels and which produce lesser hemolysis, are inferior to ribavirin for treating cHCV. This mechanism can also explain the observed RBV synergy with direct antiviral agents. This hypothesis is testable and may lead to newer and safer medications for treating cHCV infection.

Aminoadamantanes versus other antiviral drugs for chronic hepatitis C

BACKGROUND

Hepatitis C virus infection affects around 3% of the world population or approximately 160 million people. A variable proportion (5% to 40%) of the infected people develop clinical symptoms. Hence, hepatitis C virus is a leading cause of liver-related morbidity and mortality with hepatic fibrosis, end-stage liver cirrhosis, and hepatocellular carcinoma as the dominant clinical sequelae. Combination therapy with pegylated (peg) interferon-alpha and ribavirin achieves sustained virological response (that is, undetectable hepatitis C virus RNA in serum by sensitivity testing six months after the end of treatment) in approximately 40% to 80% of treated patients, depending on viral genotype. Recently, a new class of drugs have emerged for hepatitis C infection, the direct acting antivirals, which in combination with standard therapy or alone can lead to sustained virological response in 80% or more of treated patients. Aminoadamantanes, mostly amantadine, are antiviral drugs used for the treatment of patients with chronic hepatitis C. We have previously systematically reviewed amantadine versus placebo or no intervention and found no significant effects of the amantadine on all-cause mortality or liver-related morbidity and on adverse events in patients with hepatitis C. Overall, we did not observe a significant effect of amantadine on sustained virological response. In this review, we systematically review aminoadamantanes versus other antiviral drugs.

OBJECTIVES

To assess the beneficial and harmful effects of aminoadamantanes versus other antiviral drugs for patients with chronic hepatitis C virus infection by conducting a systematic review with meta-analyses and trial sequential analyses of randomised clinical trials.

SEARCH METHODS

The Cochrane Hepato-Biliary Group Controlled Trials Register (1996 to December 2013), the Cochrane Central Register of Controlled Trials (CENTRAL) (Issue 11 of 12, 2013), MEDLINE (1946 to December 2013), EMBASE (1974 to December 2013), Science Citation Index EXPANDED (1900 to December 2013), the WHO International Clinical Trials Registry Platform (www.who.int/ictrp), Google Scholar, and Eudrapharm up to December 2013. Furthermore, full text searches were conducted until December 2013.

SELECTION CRITERIA

Randomised clinical trials assessing aminoadamantanes in participants with chronic hepatitis C virus infection.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data. RevMan Analysis was used for statistical analysis of dichotomous data using risk ratio (RR) with 95% confidence intervals (CI). Methodological domains were used to assess the risk of systematic errors ('bias'). We used trial sequential analysis to assess risk of random errors ('play of chance').

MAIN RESULTS

Six randomised clinical trials with 581 participants with chronic hepatitis C were included. All trials had high risk of bias. The included trials compared amantadine versus other antiviral drugs: ribavirin, mycophenolate mofetil, interferon-alpha, or interferon-gamma. Standard antiviral therapy (interferon-alpha, interferon-alpha plus ribavirin, or peg interferon alpha) was administered equally to the intervention and the control groups in five trials, depending on when the trial was conducted. Four trials compared amantadine versus ribavirin. There were no deaths or liver-related morbidity in the two intervention groups (0/216 (0%) versus 0/211 (0%); 4 trials; very low quality of the evidence). The lower estimated risk for (serious) adverse events leading to treatment discontinuation with amantadine was imprecise (RR 0.56, 95% CI 0.27 to 1.16; based on 10/216 (5%) versus 18/211 (9%) participants in 4 trials; very low quality of the evidence). There were more participants with failure of sustained virological response in the amantadine group than in the ribavirin group (206/216 (96%) versus 176/211 (84%); RR 1.14, 95% CI 1.07 to 1.22, 4 trials; low quality of the evidence). Amantadine versus ribavirin more often failed to achieve end-of follow-up biochemical response (41/46 (89%) versus 31/46 (67%); RR 1.31, 95% CI 1.05 to 1.63; 2 trials; very low quality of the evidence). One trial compared amantadine versus mycophenolate mofetil. There were no significant differences between the two treatment groups, except that amantadine was inferior to mycophenolate mofetil regarding the outcome failure to achieve end-of treatment virological response (low quality of evidence). One trial each compared amantadine versus interferon-alpha or interferon-gamma. Both comparisons showed no significant differences in the treatment outcomes (very low quality of the evidence). The observed effects could be due to real effects, systematic errors (bias), or random errors (play of chance). This possible influence on the observed effect by play of chance is due to the fact that trial sequential analyses could not confirm our findings. We were not able to perform meta-analyses on failure of histological improvement and quality of life due to lack of valid data in all trial comparisons.

AUTHORS' CONCLUSIONS

This systematic review has identified evidence of very low quality for the key outcomes of all-cause mortality or liver-related morbidity and adverse events in people with chronic hepatitis C when treated with amantadine compared with ribavirin, mycophenolate, interferon-alpha, or interferon-gamma. The timeframe for measuring the composite outcome was insufficient in the included trials. There was low quality evidence that amantadine led to more participants who failed to achieve sustained virological response compared with ribavirin. This observation may be real or caused by systematic errors (bias), but it does not seem to be caused by random error (play of chance). Due to the low quality of the evidence, we are unable to determine definitively whether amantadine is less effective than other antivirals in patients with chronic hepatitis C. As it appears less likely that future trials assessing amantadine or potentially other aminoadamantanes for patients with chronic hepatitis C would show strong benefits, it is probably better to focus on the assessments of other direct acting antiviral drugs. We found no evidence assessing other aminoadamantanes in randomised clinical trials in order to recommend or refute their use.

Aminoadamantanes for chronic hepatitis C

BACKGROUND

Around 3% of the world's population (approximately 160 million people) are chronically infected with hepatitis C virus. The proportion of infected people who develop clinical symptoms varies between 5% and 40%. Combination therapy with pegylated interferon-alpha plus ribavirin eradicates the virus from the blood six months after treatment (sustained virological response) in approximately 40% to 80% of infected patients, depending on the viral genotype. New antiviral agents, such as boceprevir and telaprevir, in combination with standard therapy, can increase sustained virological response in genotype 1 infected patients to at least 70%. There is therefore an unmet need for drugs that can achieve a higher proportion of sustained virological response. Aminoadamantanes are antiviral drugs used for treatment of patients with chronic hepatitis C.

OBJECTIVES

To assess the beneficial and harmful effects of aminoadamantanes for patients with chronic hepatitis C infection by conducting a systematic review with meta-analyses of randomised clinical trials, as well as trial sequential analyses.

SEARCH METHODS

We conducted electronic searches of the Cochrane Hepato-Biliary Group Controlled Trials Register (1996 to December 2013), the Cochrane Central Register of Controlled Trials (CENTRAL) 2013, Issue 11 of 12 (1995 to December 2013), MEDLINE (1946 to December 2013), EMBASE (1974 to December 2013), Science Citation Index EXPANDED (1900 to December 2013), the WHO International Clinical Trials Registry Platform (www.who.int/ictrp), Google Scholar, and Eudrapharm up to December 2013 and checked the reference lists of identified publications.

SELECTION CRITERIA

Randomised clinical trials assessing aminoadamantanes in patients with chronic hepatitis C infection.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data. We assessed for risks of systematic errors ('bias') using the 'Risk of bias' tool. We analysed dichotomous data with risk ratio (RR) and continuous data with mean difference (MD) or standardised mean difference (SMD), both with 95% confidence intervals (CI). We used trial sequential analysis to assess the risk of random errors ('play of chance'). We assessed quality using the GRADE system.

MAIN RESULTS

We included 41 randomised clinical trials with 6193 patients with chronic hepatitis C. All trials had high risk of bias. All included trials compared amantadine versus placebo or no intervention. Standard antiviral therapy was administered equally to the intervention and the control groups in 40 trials. The standard antiviral therapy, which was administered to both intervention groups, was interferon-alpha, interferon-alpha plus ribavirin, and peg interferon-alpha plus ribavirin, depending on the time when the trial was conducted.When we meta-analysed all trials together, the overall results demonstrated no significant effects of amantadine, when compared with placebo or no intervention, on our all-cause mortality or liver-related morbidity composite outcome (5/2353 (0.2%) versus 6/2264 (0.3%); RR 0.90, 95% CI 0.38 to 2.17; I² = 0%; 32 trials; very low quality). There was also no significant effect on adverse events (288/2869 (10%) versus 293/2777 (11%); RR 0.98, 95% CI 0.84 to 1.14; I² = 0%; 35 trials; moderate quality). We used both fixed-effect and random-effects meta-analyses. Amantadine, when compared with placebo or no intervention, did not significantly influence the number of patients who failed to achieve a sustained virological response (1821/2861 (64%) versus 1737/2721 (64%); RR 0.98, 95% CI 0.95 to 1.02; I² = 35%; 35 trials; moderate quality). However, in the subgroup using interferon plus ribavirin, amantadine decreased the number of patients who failed to achieve a sustained virological response (422/666 (63%) versus 447/628 (71%); RR 0.89, 95% CI 0.83 to 0.96; I² = 41%; 11 trials; low quality). Similar results were found for failure to achieve an end of treatment virological response. Amantadine, when compared with placebo or no intervention, significantly decreased the number of patients without normalisation of alanine aminotransferase (ALT) serum levels at the end of treatment (671/1141 (59%) versus 732/1100 (67%); RR 0.88, 95% CI 0.83 to 0.94; I² = 47%; 19 trials; low quality). Amantadine, when compared with placebo or no intervention, did not significantly influence the end of follow-up biochemical response (1133/1896 (60%) versus 1151/1848 (62%); RR 0.95, 95% CI 0.91 to 1.00; I² = 49%; 21 trials; low quality).The observed beneficial effects could be true effects but could also be due to both systematic errors (bias) and random errors (play of chance). The latter is due to the fact that trial sequential analyses could not confirm or refute our findings. We were not able to perform meta-analyses for failure of histological improvement or quality of life due to a lack of valid data.

AUTHORS' CONCLUSIONS

This systematic review does not demonstrate any significant effects of amantadine on all-cause mortality or liver-related morbidity composite outcome and on adverse events in patients with hepatitis C; however, the median trial duration was 12 months, with a median follow-up of six months, which is not long enough to assess the composite outcome sufficiently. Overall, we did not see an effect of amantadine on failure to achieve a sustained virological response. Subgroup analyses demonstrated that the combination of amantadine plus interferon-alpha and ribavirin seems to increase the number of patients achieving a sustained virological response. This finding may be caused by both systematic errors (bias) and risks of random errors (play of chance), but it could also be real. Based on the results of the overall evidence, it appears less likely that future trials assessing amantadine for patients with chronic hepatitis C will show strong benefits. Therefore, it is probably advisable to wait for the results of trials assessing other direct-acting antiviral drugs. In the absence of convincing evidence of benefit, the use of amantadine is justified in the context of randomised clinical trials assessing the effects of combination therapy. We found a lack of evidence on other aminoadamantanes than amantadine.

Nitazoxanide for chronic hepatitis C

BACKGROUND

Hepatitis C infection is a disease of the liver caused by the hepatitis C virus. The estimated number of chronically infected people with hepatitis C virus worldwide is about 150 million people. Every year, another three to four million people acquire the infection. Chronic hepatitis C is a leading cause of liver-related mortality and morbidity. It is estimated that around 5% to 20% of people with the infection will develop liver cirrhosis, which increases the risk of hepatocellular carcinoma and liver failure. Until 2011, the combination therapy of pegylated interferon-alpha (peginterferon) and ribavirin was the approved standard treatment for chronic hepatitis C. In 2011, first-generation direct-acting antivirals have been licensed, for use in combination with peginterferon and ribavirin for treating hepatitis C virus genotype 1 infection. Nitazoxanide is another antiviral drug with broad antiviral activity and may have potential as an effective alternative, or an addition to standard treatment for the treatment of the hepatitis C virus.

OBJECTIVES

To assess the benefits and harms of nitazoxanide in people with chronic hepatitis C virus infection.

SEARCH METHODS

We searched The Cochrane Hepato-Biliary Group Controlled Trials Register (last searched April 2013), The Cochrane Central Register of Controlled Trials (CENTRAL) (2013, Issue 3), MEDLINE (Ovid SP, 1948 to April 2013), EMBASE (Ovid SP, 1980 to April 2013), LILACS (1983 to April 2013), and Science Citation Index EXPANDED (ISI Web of Knowledge, 1900 to April 2013), using the search strategies and the expected time spans. We also scanned reference lists of identified studies.We also searched ClinicalTrials.gov and the World Health Organization's International Clinical Trials Registry Platform search portal for registered trials, either completed or ongoing (April 2013).

SELECTION CRITERIA

We included randomised clinical trials that examined the effects of nitazoxanide versus placebo, no intervention, or any other intervention in patients with chronic hepatitis C. We considered any co-intervention, including standard treatment, if delivered to all intervention groups of the randomised trial concerned.

DATA COLLECTION AND ANALYSIS

Two review authors extracted data independently. We assessed the risk of systematic errors ('bias') by evaluation of bias risk domains. We used Review Manager 5.2 for the statistical analyses of dichotomous outcome data with risk ratio (RR) and of continuous outcome data with mean difference (MD). For meta-analyses, we used a fixed-effect model and a random-effects model, along with an assessment of heterogeneity. We assessed risk of random errors ('play of chance') using trial sequential analysis. We assessed the quality of the evidence using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system to present review results in 'Summary of findings' tables.

MAIN RESULTS

We included seven randomised clinical trials with a total of 538 participants with chronic hepatitis C. Participants were 18 years of age or older, all diagnosed with chronic hepatitis C genotype 1 or 4. All of the trials had a high risk of bias. All of the trials compared nitazoxanide with placebo or no intervention, and six out of seven of the trials included different antiviral co-interventions administered equally to all intervention groups. Only one trial, comparing nitazoxanide plus peginterferon and ribavirin versus no intervention plus peginterferon and ribavirin, provided information that there were no deaths due to any cause or due to chronic hepatitis C (100 participants, very low quality evidence). The relative effect of nitazoxanide versus placebo or no intervention on adverse events was uncertain (37 out of 179 (21%) versus 30 out of 152 (20%); RR 1.10; 95% CI 0.71 to 1.71; I(2) = 65%; four trials; very low quality evidence). Nitazoxanide decreased the risk of failure to achieve sustained virological response when compared with placebo or no intervention (159 out of 290 (55%) versus 133 out of 208 (64%); RR 0.85; 95% CI 0.75 to 0.97; I(2) = 0%; seven trials; low quality evidence) and also the risk of failure to achieve virological end-of-treatment response (125 out of 290 (43%) versus 110 out of 208 (53%); RR 0.81; 95% CI 0.69 to 0.96; I(2) = 46%; seven trials; low quality evidence). Trial sequential analysis supported the meta-analysis result for sustained virological response, but not the meta-analysis for virological end-of-treatment response. Meta-analysis also showed that nitazoxanide did not decrease the number of participants who showed no improvement in alanine aminotransferase and aspartate aminotransferase serum levels when compared with placebo or no intervention (52 out of 97 (54%) versus 47 out of 95 (49%); RR 1.09; 95% CI 0.84 to 1.42; I(2) = 0%; three trials; very low quality evidence). None of the included trials assessed the effects of nitazoxanide on morbidity or on quality of life. Histological changes were only reported on a subset of three participants out of thirteen participants included in a long term-follow-up trial.

AUTHORS' CONCLUSIONS

We found very low quality, or no, evidence on nitazoxanide for clinically- or patient-relevant outcomes, such as all-cause mortality, chronic hepatitis C-related mortality, morbidity, and adverse events in participants with chronic hepatitis C genotype 1 or 4 infection. Our results of no improvement in alanine aminotransferase and aspartate aminotransferase serum levels were also uncertain. No conclusion could be drawn about liver histology because of a lack of data. Our results indicate that nitazoxanide might have an effect on sustained virological response and virological end-of-treatment response. However, both results could be influenced by systematic errors because all the trials included in the review had a high risk of bias. Furthermore, only the beneficial effect on number of participants achieving sustained virological response was supported when we applied trial sequential analysis. The results on virological end-of-treatment response might, therefore, be caused by a random error. We totally lack information on the effects of nitazoxanide in participants with chronic hepatitis C genotypes 2 or 3 infection. More randomised clinical trials with a low risk of bias are needed to assess the effects of nitazoxanide for chronic hepatitis C.

Update on combinations of DAAs with and without pegylated-interferon and ribavirin: triple and quadruple therapy more than doubles SVR

Monotherapy is an ineffective way to treat hepatitis C and it leads to rapid development of resistance. An increasing number of drugs are currently being developed for the treatment of hepatitis C. This allows combination strategies that can overcome the development of resistance and improve sustained virologic response rates. This article focuses on the 2 main strategies in development: quadruple combination therapies, including pegylated-interferon and triple/quadruple pegylated-interferon free combination therapies. If the first combinations are leading to extremely high sustained virologic responses, the second ones offer hope that the era of pegylated-interferon will end soon.

Current treatment of choice for chronic hepatitis C infection

More than three million Americans have chronic hepatitis C infection, and the disease remains one of the most common blood-borne infections in the US. Treatment is focused on the chronic form of the disease, because the acute one tends to be self-limiting. In this article, we review the recent literature regarding the most effective therapy against hepatitis C infection, to confirm the current treatment of choice for the disease. We conclude that combination therapy with pegylated interferon and ribavirin remains the initial treatment of choice. New research focusing on adjuvant therapies, such as protease and polymerase inhibitors, has yielded early data that appear to be promising.