Hepatitis C virus treatment in the real world: optimising treatment and access to therapies

Hepatitis C infection: A multi-faceted systemic disease with clinical, patient reported and economic consequences

Hepatitis C virus infection (HCV) affects approximately 170-200 million individuals globally. HCV is one of the primary causes of hepatocellular carcinoma (HCC) and cirrhosis and has been identified as the leading indication for liver transplantation in most Western countries. Because HCV is a systemic disease with hepatic, extrahepatic, economic and patient reported consequences, it is important for healthcare practitioners to understand the comprehensive and multi-faceted picture of this disease. In this context, it is important to fully appreciate the impact of HCV on the individual patient and the society. With the recent advent of the new generation of direct antiviral agents, the long standing goal of eradicating HCV in most infected patients has been accomplished. Therefore, now more than ever, it is critical to assess the total benefits of sustained virological response in a comprehensive manner. This should not be limited to the clinical benefits of HCV cure, but also to account for the improvement of patient reported health and economic outcomes of HCV cure. It is only through this comprehensive approach to HCV and its treatment that we will understand the full impact of this disease and the tremendous gains that have been achieved with the new antiviral regimens.

Quantification of Core Antigen Monitors Efficacy of Direct-acting Antiviral Agents in Patients With Chronic Hepatitis C Virus Infection

BACKGROUND & AIMS

Widespread use of direct-acting antiviral (DAA) agents to treat patients with hepatitis C virus (HCV) infection has reduced the need for monitoring of HCV RNA levels, because viral kinetics do not predict sustained virologic response (SVR) to these drugs. However, the performance of cheaper tests such as the assay to quantify HCV core antigen (HCV Ag) has not been determined. We investigated the accuracy of the HCV Ag test in predicting which patients receiving DAAs will achieve SVRs at week 12 (SVR12).

METHODS

We performed a prospective study of 58 patients infected with HCV genotypes 1-5 (45% with HCV genotype 1, 72% with cirrhosis) receiving DAA therapy from the Liver Center at the Università degli Studi of Milan in Italy from January to March 2015. We collected blood samples and measured levels of HCV Ag and HCV RNA at baseline, after 2 and 4 weeks of treatment, the end of treatment, and 12 weeks after treatment ended. We compared the ability of these assays to predict which patients would have SVR12.

RESULTS

The median baseline level of HCV RNA was 5.79 log10 IU/mL (range, 3.51-7.31 log10 IU/mL) and of HCV Ag was 3226.87 fmol/L (range, 17.30-54,927.00 fmol/L). HCV Ag became undetectable in 71% of patients at week 2, 84% at week 4, and 93% at the end of treatment. HCV RNA became undetectable in 10% of patients at week 2, 43% at week 4, and 100% at the end of treatment (P < .0001). Concordance between the tests in identifying patients who would achieve SVR12 was 40% at week 2, 55% at week 4, and 95% at the end of treatment. Fifty-three of 58 patients (91%) achieved an SVR12; the test for HCV Ag identified 97% of these patients. The tests for HCV Ag and HCV RNA predicted which patients would have SVR12 with positive predictive values of 90% vs 83%, respectively, at week 2 and 89% vs 92%, respectively, at week 4.

CONCLUSIONS

Tests that measure HCV Ag monitor efficacy of DAA therapy for HCV infection as well as assays that measure HCV RNA and can be recommended for clinical practice. However, measurement of HCV RNA after treatment can rule out relapse in HCV Ag-positive patients.

Twelve-week ribavirin-free direct-acting antivirals for treatment-experienced Chinese with HCV genotype 1b infection including cirrhotic patients

BACKGROUND

Treatment-experienced chronic hepatitis C (CHC) genotype (GT) 1b represents a major medical burden in China. We evaluate the efficacy, safety and cost-effectiveness of ribavirin (RBV)-free pan-oral direct-acting antivirals (DAAs) in treatment-experienced Chinese with GT1b CHC, including patients with cirrhosis.

METHODS

One hundred forty treatment-experienced GT1b CHC Chinese with and without cirrhosis were included in this study. Ninety-four patients were treated with either daclatasvir (DCV, 60 mg)-sofosbuvir (SOF, 400 mg) (group 1, n = 46) or ledipasvir (LDV, 90 mg)-SOF (400 mg) (group 2, n = 48) for 12 weeks. Forty-six patients treated with pegylated interferon and RBV therapy for 72 weeks were enrolled as the control group (group 3). Patients were followed at 4-weekly intervals till 24 weeks after the end of treatment.

RESULTS

All patients in group 1 (46/46, 100 %) and 2 (48/48, 100 %) had achieved sustained virologic response at 24 weeks after the end of treatment (SVR 24), which was significantly higher than that of group 3 (13/46, 28.3 %) (p < 0.001). The SVR 24 rates of cirrhotic patients in group 1 (27/27, 100 %) and 2 (27/27, 100 %) were also significantly higher than that of group 3 (3/25, 12 %) (p < 0.001). Twelve weeks of RBV-free LDV-SOF and DCV-SOF was either cost-saving or cost-effective. Adverse events were significantly lower in group 1 and 2 compared with group 3 (p < 0.001).

CONCLUSION

Compared with standard therapies, 12 weeks of RBV-free DAA therapies is highly effective, well tolerated and cost-effective in treatment-experienced Chinese with GT1b CHC including patients with cirrhosis.

Biochemical Characterization of the Active Anti-Hepatitis C Virus Metabolites of 2,6-Diaminopurine Ribonucleoside Prodrug Compared to Sofosbuvir and BMS-986094

Ribonucleoside analog inhibitors (rNAI) target the hepatitis C virus (HCV) RNA-dependent RNA polymerase nonstructural protein 5B (NS5B) and cause RNA chain termination. Here, we expand our studies on β-d-2'-C-methyl-2,6-diaminopurine-ribonucleotide (DAPN) phosphoramidate prodrug 1 (PD1) as a novel investigational inhibitor of HCV. DAPN-PD1 is metabolized intracellularly into two distinct bioactive nucleoside triphosphate (TP) analogs. The first metabolite, 2'-C-methyl-GTP, is a well-characterized inhibitor of NS5B polymerase, whereas the second metabolite, 2'-C-methyl-DAPN-TP, behaves as an adenosine base analog. In vitro assays suggest that both metabolites are inhibitors of NS5B-mediated RNA polymerization. Additional factors, such as rNAI-TP incorporation efficiencies, intracellular rNAI-TP levels, and competition with natural ribonucleotides, were examined in order to further characterize the potential role of each nucleotide metabolite in vivo Finally, we found that although both 2'-C-methyl-GTP and 2'-C-methyl-DAPN-TP were weak substrates for human mitochondrial RNA (mtRNA) polymerase (POLRMT) in vitro, DAPN-PD1 did not cause off-target inhibition of mtRNA transcription in Huh-7 cells. In contrast, administration of BMS-986094, which also generates 2'-C-methyl-GTP and previously has been associated with toxicity in humans, caused detectable inhibition of mtRNA transcription. Metabolism of BMS-986094 in Huh-7 cells leads to 87-fold higher levels of intracellular 2'-C-methyl-GTP than DAPN-PD1. Collectively, our data characterize DAPN-PD1 as a novel and potent antiviral agent that combines the delivery of two active metabolites.

Drug Pricing Evolution in Hepatitis C

Objective

We aimed to determine the association between the stepwise increase in the sustained viral response (SVR) and Swiss and United States (US) market prices of drug regimens for treatment-naive, genotype 1 chronic hepatitis C virus (HCV) infection in the last 25 years. We identified the following five steps in the development of HCV treatment regimens: 1) interferon (IFN)-α monotherapy in the early '90s, 2) IFN-α in combination with ribavirin (RBV), 3) pegylated (peg) IFN-α in combination with RBV, 4) the first direct acting antivirals (DAAs) (telaprevir and boceprevir) in combination with pegIFN-α and RBV, and 5) newer DAA-based regimens, such as sofosbuvir (which is or is not combined with ledipasvir) and fixed-dose combination of ritonavir-boosted paritaprevir and ombitasvir in combination with dasabuvir.

Design

We performed a linear regression and mean cost analysis to test for an association between SVRs and HCV regimen prices. We conducted a sensitivity analysis using US prices at the time of US drug licensing. We selected randomized clinical trials of drugs approved for use in Switzerland from 1997 to July 2015 including treatment-naïve patients with HCV genotype 1 infection.

Results

We identified a statistically significant positive relationship between the proportion of patients achieving SVRs and the costs of HCV regimens in Switzerland (with a bivariate ordinary least square regression yielding an R2 measure of 0.96) and the US (R2 = 0.95). The incremental cost per additional percentage of SVR was 597.14 USD in Switzerland and 1,063.81 USD in the US.

Conclusion

The pricing of drugs for HCV regimens follows a value-based model, which has a stable ratio of costs per achieved SVR over 25 years. Health care systems are struggling with the high resource use of these new agents despite their obvious long-term advantages for the overall health of the population. Therefore, the pharmaceutical industry, health care payers and other stakeholders are challenged with finding new drug pricing schemes to treat the entire population infected with HCV.

Hepatitis C virus genotype 3: Meta-analysis on sustained virologic response rates with currently available treatment options

AIM: To address the therapeutic efficacy of various treatment regimens in genotype 3 selecting randomized clinical trials and prospective National Cohort Studies.

METHODS: (1) PEG-INF-based therapy including sofosbuvir (SOF) + RBV for 12 wk vs SOF + RBV 24 wk; (2) SOF + RBV therapy 12 wk/16 wk vs 24 wk; and (3) the role of RBV in SOF + daclatasvir (DCV) and SOF + ledipasvir (LDV) combinations. This meta-analysis provides robust information with the intention of addressing treatment strategy for hepatitis C virus genotype 3.

RESULTS: A combination treatment including SOF + RBV + PEG-IFN for 12 wk notes better SVR than with only SOF + RBV for 12 wk, although its association with more frequent adverse effects may be a limiting factor. Longer duration therapy with SOF + RBV (24 wk) has achieved higher SVR rates than shorter durations (12 or 16 wk). SOF + LDV are not an ideal treatment for genotype 3.

CONCLUSION: Lastly, SOF + DCV combination is probably the best oral therapy option and the addition of RBV does not appear to be needed to increase SVR rates substantially.

Dual therapy with peg-interferon and ribavirin in thalassemia major patients with chronic HCV infection: Is there still an indication?

BACKGROUND

Iron overload and hepatitis C virus (HCV) infection together can lead to chronic liver damage in thalassemia major (TM) patients.

AIMS

We investigated viral, genetic, and disease factors influencing sustained virological response (SVR) after peg-interferon and ribavirin therapy in TM patients with HCV infection.

METHODS

We analyzed 230 TM patients with HCV infection (mean age 36.0±6.3 years; 59.1% genotype 1; 32.2% genotype 2; 3.4% genotype 3; and 5.3% genotype 4; 28.7% carried CC allele of rs12979860 in IL28B locus; 79.6% had chronic hepatitis and 20.4% cirrhosis; 63.5% naive and 36.5% previously treated with interferon alone) treated in 14 Italian centers.

RESULTS

By multivariate regression analysis SVR was independently associated with CC allele of IL28B SNP (OR 2.98; CI 95% 1.29-6.86; p=0.010) and rapid virologic response (OR 11.82; CI 95% 3.83-36.54; p<0.001) in 136 genotype 1 patients. Combining favorable variables the probability of SVR ranged from 31% to 93%. In genotype 2 patients, only RVR (OR 8.61; CI 95% 2.85-26.01; p<0.001) was associated with SVR higher than 80%. In 3 patients with cirrhosis a decompensation of liver or heart disease were observed. Over 50% of patients increased blood transfusions.

CONCLUSION

Dual therapy in TM patients with chronic HCV infection is efficacious in patients with the best virological, genetic and clinical predictors. Patients with cirrhosis have an increased risk of worsening liver or heart disease.

How have the recent advances in antiviral therapy impacted the management of virus-related hepatocellular carcinoma?

INTRODUCTION

Whether the recent advances in antiviral therapy including nucleos(t)ide analogue (NA) or interferon (IFN) impacts the management of patients with virus-related hepatocellular carcinoma (HCC) remains unclear.

AREA COVERED

The beneficial effects of antiviral therapy on HCC patients receiving curative treatment, transhepatic arterial chemoembolization (TACE), or radiotherapy are reviewed and discussed.

EXPERT OPINION

For patients with HCV-related HCC after curative treatment, interferon (IFN)-based therapy has been shown to improve the survival and reduces the risk of HCC recurrence. However, it carries the risk of adverse effects, especially in cirrhotic patients. Therefore, the benefit of IFN should be weighted against its risk in each individual. For patients with HBV-related HCC after curative treatments, antiviral treatment with NA has been found to improve liver function, overall survival, and possibly reduce the risk of HCC recurrence. In contrast, these benefits were not consistently observed in those receiving IFN treatment. In HCC patients receiving palliative TACE or radiotherapy, HBV reactivation occurs in a small proportion of them, and preemptive NA treatment can reduce the risk of hepatitis flare due to viral reactivation. Therefore, NA treatment after curative treatments or TACE is strongly recommended for HCC patients with high viral load (HBV DNA> 2000 IU/mL).