Accumulation of refractory factors for pegylated interferon plus ribavirin therapy in older female patients with chronic hepatitis C

Why highly effective drugs are not enough: the need for an affordable solution to eliminating HCV

INTRODUCTION

Because of the rapid pace of development of new direct-acting antiviral (DAA) drugs, chronic hepatitis C virus (HCV) infection is now increasingly considered curable. However, the emphasis on DAA therapies disregards key issues related to cost, availability, and antiviral resistance. Areas covered: This perspective provides an overview of current HCV therapies and the development of DAAs, followed by a discussion of the limitations of DAA therapy. A literature search was used to select relevant studies, and a web search for relevant news articles and press releases was conducted. Expert commentary: Despite cure rates exceeding 90%, now is not the time to declare victory against HCV but to reinforce recent progress by addressing the issues of cost and availability as well as by developing strategies to manage antiviral resistance. Future drug development efforts should place greater emphasis on targeting host factors required for HCV replication, for which the barrier to resistance is higher, and effort should continue to develop a vaccine against HCV. Finally, efforts should be made to facilitate large-scale screening in endemic areas to identify and treat patients as early as possible to reduce long-term risks of advanced liver disease and their attendant costs of management.

The practical management of chronic hepatitis C infection in Japan - dual therapy of daclatasvir + asunaprevir

Without treatment, many of the 200 million people worldwide with chronic hepatitis C virus (HCV) infection will develop cirrhosis or liver cancer. Japan was the first nation to approve an interferon-free therapy for HCV, and sustained viral response (SVR) rates >90% have been achieved with asunaprevir, a protease inhibitor, plus daclatasvir, an inhibitor of the non-structural 5A (NS5A) protein. Areas covered: This review provides an overview of the results from both clinical trials and real world experience with asunaprevir and daclatasvir therapy focused primarily on Japan. A literature search using the keywords 'asunaprevir,' 'daclatasvir,' 'interferon-free therapy,' and 'direct-acting antiviral drugs' was initially used to select relevant literature for inclusion in the review. Expert commentary: While not approved in the United States, dual therapy with asunaprevir plus daclatasvir has already been successfully used in Japan and throughout East Asia to treat many thousands of patients. Pre-existing or treatment-emergent NS5A-Y93 or -L31 resistance-associated variants (RAVs) may lead to viral breakthrough, and alternative therapies should be considered for these patients, but patients who harbor NS5A RAVs only at low frequency are likely to achieve SVR. The therapy has also been shown to be safe and effective with renal dysfunction or liver cirrhosis.

HCV Drug Resistance Challenges in Japan: The Role of Pre-Existing Variants and Emerging Resistant Strains in Direct Acting Antiviral Therapy

Sustained virological response (SVR) rates have increased dramatically following the approval of direct acting antiviral (DAA) therapies. While individual DAAs have a low barrier to resistance, most patients can be successfully treated using DAA combination therapy. However, DAAs are vulnerable to drug resistance, and resistance-associated variants (RAVs) may occur naturally prior to DAA therapy or may emerge following drug exposure. While most RAVs are quickly lost in the absence of DAAs, compensatory mutations may reinforce fitness. However, the presence of RAVs does not necessarily preclude successful treatment. Although developments in hepatitis C virus (HCV) therapy in Asia have largely paralleled those in the United States, Japan’s July 2014 approval of asunaprevir plus daclatasvir combination therapy as the first all-oral interferon-free therapy was not repeated in the United States. Instead, two different combination therapies were approved: sofosbuvir/ledipasvir and paritaprevir/ritonavir/ombitasvir/dasabuvir. This divergence in treatment approaches may lead to differences in resistance challenges faced by Japan and the US. However, the recent approval of sofosbuvir plus ledipasvir in Japan and the recent submissions of petitions for approval of paritaprevir/ritonavir plus ombitasvir suggest a trend towards a new consensus on emerging DAA regimens.

Optimizing triple therapy and IFN/RBV-free regimens for hepatitis C virus infection

Treatment of chronic hepatitis C virus infection has substantially improved following the advent of direct acting antiviral (DAA) agents. Although the first generation protease inhibitors telaprevir and boceprevir improved sustained viral response (SVR) rates, adverse events remain severe and immature termination of the therapy is frequent; however, intensive dose modification has improved completion and SVR rates. Interferon-free DAA combination therapies, such as asunaprevir and daclatasvir dual therapy are under development and promise higher SVR rates with fewer adverse events. Resistance monitoring and modification of DAA therapy based on pre-existing or de novo resistance variants should be considered. Future therapies are expected to have pan-genotypic activity with shorter duration and improved tolerability, even among cirrhotic and liver transplant patients.

Emerging treatments for chronic hepatitis C

Advances in understanding the hepatitis C virus (HCV) life cycle and the urgent need to find complementary direct-acting antiviral (DAA) therapies has led to substantial advancements in treating chronic hepatitis C. The introduction of telaprevir and boceprevir in 2011 increased the sustained virological response (SVR) rate from approximately 50% to > 70%, but this therapy further restricted patient eligibility and is only approved for treating HCV genotype 1 infection. Interferon has long remained the backbone of HCV therapy and helps prevent viral breakthrough. However, interferon has limited effectiveness and is associated with severe adverse effects and toxicity, especially among cirrhotic patients. Moving to interferon-free therapies should greatly improve SVR rates and offer new treatments for other HCV genotypes and for ineligible patients or patients failing to respond to prior therapies. However, without the relative safety of interferon to suppress viral escape, vigilance will be required to select appropriate therapies and monitor resistance. Several DAAs are currently undergoing clinical trials and will soon undergo the approval process. Goals of future HCV clinical research will be to identify combinations of DAAs with high genetic barriers, investigate optimal treatment doses and durations, and determine the role of ribavirin in DAA therapies.

Serum apolipoprotein B-100 concentration predicts the virological response to pegylated interferon plus ribavirin combination therapy in patients infected with chronic hepatitis C virus genotype 1b

Host lipoprotein metabolism is associated closely with the life cycle of hepatitis C virus (HCV), and serum lipid profiles have been linked to the response to pegylated interferon (Peg-IFN) plus ribavirin (RBV) therapy. Polymorphisms in the human IL28B gene and amino acid substitutions in the core and interferon sensitivity-determining region (ISDR) in NS5A of HCV genotype 1b (G1b) were also shown to strongly affect the outcome of Peg-IFN plus RBV therapy. In this study, an observational cohort study was performed in 247 HCV G1b-infected patients to investigate whether the response to Peg-IFN and RBV combination therapy in these patients is independently associated with the level of lipid factors, especially apolipoprotein B-100 (apoB-100), an obligatory structural component of very low density lipoprotein and low density lipoprotein. The multivariate logistic analysis subsequently identified apoB-100 (odds ratio (OR), 1.602; 95% confidence interval (CI), 1.046-2.456), alpha-fetoprotein (OR, 0.764; 95% CI, 0.610-0.958), non-wild-type ISDR (OR, 5.617; 95% CI, 1.274-24.754), and the rs8099917 major genotype (OR, 34.188; 95% CI, 10.225-114.308) as independent factors affecting rapid initial virological response (decline in HCV RNA levels by ≥3-log10 at week 4). While lipid factors were not independent predictors of complete early or sustained virological response, the serum apoB-100 level was an independent factor for sustained virological response in patients carrying the rs8099917 hetero/minor genotype. Together, we conclude that serum apoB-100 concentrations could predict virological response to Peg-IFN plus RBV combination therapy in patients infected with HCV G1b, especially in those with the rs8099917 hetero/minor genotype.

Treatment of chronic hepatitis C virus infection in Japan: update on therapy and guidelines

Hepatitis C virus (HCV) infection is a serious health problem leading to cirrhosis, liver failure and hepatocellular carcinoma. The recent introduction of telaprevir, which was approved in November 2011, in combination with peg-interferon and ribavirin is expected to markedly improve the eradication rate of the virus. However, side effects of triple therapy may be severe. In a phase three III clinical trial, 2250 mg of telaprevir, which is the same dosage used in clinical trials in Western countries, was given to Japanese patients. As this dosage is considered to be relatively high for Japanese patients, who typically have lower weight than patients in Western countries, reduction of telaprevir is recommended in the 2012 revision of the guidelines established by the Study Group for the Standardization of Treatment of Viral Hepatitis Including Cirrhosis published by the Ministry of Health, Labour and Welfare of Japan. Other protease inhibitors with fewer side effects are now in clinical trials in Japan. Alternatively, treatment of patients with combination of direct acting antivirals without interferon has been reported. In this review we summarize current treatment options in Japan and discuss how we treat patients with chronic HCV infection.

Association of visceral obesity with high viral load and histological findings in elderly patients with genotype 1 chronic hepatitis C

OBJECTIVE

Genotype 1 chronic hepatitis C (G1CHC) is generally accompanied by metabolic disturbances related to visceral obesity, such as insulin resistance, steatosis, or dyslipidemia. Because these abnormalities negatively influence the clinical course of G1CHC, we sought to clarify the effect of visceral obesity on the pathophysiology of G1CHC.

METHODS

We evaluated 180G1CHC patients for the presence of visceral obesity on the basis of computed tomography findings. Multivariate analysis was performed to estimate the relationship between visceral obesity and demographic, viral, and biochemical characteristics of patients. The associations of visceral obesity with histological findings and serum adipokine levels were also analyzed.

RESULTS

Multiple logistic regression analysis revealed that visceral obesity was independently associated with metabolic syndrome, platelet count, high-density lipoprotein level, and serum viral load in elderly patients (≥65 years). Multiple linear regression analysis confirmed the association between visceral obesity and high viral load. However, visceral obesity was not correlated with viral load in non-elderly patients (<65 years). Histological data (160 patients) demonstrated the significant association between visceral obesity and steatosis. Furthermore, patients with visceral obesity showed increase in the severity of fibrosis with advancing age. However, age-associated fibrosis progression was not evident in patients without visceral obesity. The serum adiponectin level was significantly low in patients with visceral obesity, whereas those of leptin, tumor necrosis factor-α, and interleukin-6 were not affected significantly.

CONCLUSION

Visceral obesity was associated with high viral load and histological damage in elderly patients with reduced adiponectin levels.

Raloxifene hydrochloride is an adjuvant antiviral treatment of postmenopausal women with chronic hepatitis C: a randomized trial

BACKGROUND & AIMS

Early menopause in women with chronic hepatitis C virus (HCV) infection is associated with a low likelihood of a sustained virological response (SVR) in conjunction with their antiviral treatment. This is potentially related to their reduced estrogen secretion. The study was done to determine whether selective estrogen receptor modulator administration might improve the efficacy of the current standard of care (SOC) treatment, pegylated interferon (PegIFN) α2a plus ribavirin (RBV), for postmenopausal women.

METHODS

One hundred and twenty-three postmenopausal women with genotype 1b chronic hepatitis C were randomly assigned to one of two treatment groups: raloxifene hydrochloride (RLX) (60 mg/day) plus SOC (PegIFNα2a 180 μg/week and RBV 600-1,000 mg/day) (n=62) or SOC only (n=61). Genotyping was performed of the polymorphism in the interleukin-28B (IL28B) gene region (rs8099917) of DNA collected from each patient.

RESULTS

One RLX-treated patient discontinued RLX because of a systemic rash following 2 weeks of treatment. Twenty-four weeks after treatment, the SVR rate was significantly higher for RLX plus SOC patients (61.3%) than for SOC only patients (34.4%) (p=0.0051). Further, the SVR rate was significantly higher for RLX plus SOC patients with IL28B TT (72.5%) than for SOC only patients with IL28B TT (39.2%) (p=0.0014), but no such relationship was observed in patients carrying the minor IL28B allele.

CONCLUSIONS

RLX improved the efficacy of SOC in the treatment of postmenopausal women with chronic hepatitis C. RLX shows promise as an adjuvant to the standard antiviral treatment of such patients.

Baseline serum cholesterol is associated with a response to pegylated interferon alfa-2b and ribavirin therapy for chronic hepatitis C genotype 2

Background. HCV infection is associated with lipid disorders because this virus utilizes the host lipid metabolism to sustain its life cycle. Several studies have indicated that higher concentrations of serum cholesterol and LDL before treatment are important predictors of higher rates of sustained virological response (SVR). However, most of these studies involved patients infected with HCV genotype 1. Thus, we performed a multi-institutional clinical study to evaluate the impact of lipid profiles on SVR rates in patients with HCV genotype 2. Methods. A total of 100 chronic hepatitis C patients with HCV genotype 2 who received peg-IFN alfa-2b and ribavirin therapy were consecutively enrolled. The significance of age, sex, BMI, AST level, ALT level, WBC, hemoglobin, platelet count, gamma-glutamyltransferase, total cholesterol level (TC), LDL level, HCV RNA, and histological evaluation was examined for SVR using logistic regression analysis. Results. The 100 patients infected with HCV genotype 2 were divided into 2 groups, an SVR group and a non-SVR group. Characteristics of each group were subsequently compared. There was no significant difference in the level of HCV RNA, BMI, platelet, TG, or stage of fibrosis between the groups. However, there were significant differences in the levels of TC and LDL-C. In multivariate logistic regression analysis using baseline characteristics, high TC level was an independent and significant risk factor (relative risk 18.59, P = 0.015) for SVR. Conclusion. Baseline serum total cholesterol levels should be considered when assessing the likelihood of sustained treatment response following the course of peg-IFN and ribavirin therapy in patients with chronic HCV genotype 2 infection.

Treatment extension may benefit female genotype 1 chronic hepatitis C patients with complete early virological response to peginterferon-alpha-2b and ribavirin combination therapy

AIM

  Little is known about the appropriate use of peginterferon-α-2b (PEG IFN-α-2b) or ribavirin (RBV) in genotype 1 chronic hepatitis C (CH-C) patients with complete early virological response (cEVR). Female patients, especially the older, are known to experience inferior treatment outcomes.

METHOD

  A total of 150 CH-C patients with cEVR treated for 48 weeks (n = 104) or 52-64 weeks (n = 46) with PEG IFN-α-2b and RBV combination therapy were retrospectively analyzed to evaluate the benefits of extended treatment.

RESULTS

  In the 48-week group, patients without a sustained virological response (SVR) were more often female (P = 0.004) and had received a significantly lower total RBV dose (P = 0.003) than those with SVR. The SVR rate in these female patients was similar to males with hepatitis C virus (HCV) RNA negativity at treatment week 8 (P = 0.413); however, it was lower than that in males with HCV RNA negativity at treatment week 12 (P = 0.005). In the 52-64-week group, although the total RBV dose (mg/kg) after treatment week 48 was less in females than in males (P = 0.027), the SVR rate in females was equivalent to that in males (P = 0.604).

CONCLUSION

  Genotype 1 CH-C patients treated with PEG IFN-α-2b and RBV combination therapy without SVR were more often female and had received a lower total RBV dose than males. The smaller SVR rate in female patients with cEVR compared to males may be overcome by extending treatment even if the RBV dose is lowered due to anemia.

Hepatocellular carcinoma: towards personalized medicine

Over the past several years, the success of genome-wide association studies (GWAS) and pharmacogenomics has gradually begun to enable personalized medicine in some fields. In the field of liver diseases, host genetic factors are now very useful in clinical practice for predicting treatment outcome and adverse reactions for pegylated interferon plus ribavirin combination therapy against chronic hepatitis C virus (HCV) infection. Recently, three virus-related hepatocellular carcinoma (HCC) GWAS were reported from Asia. One study examined hepatitis B virus-related HCC in China, where hepatitis B is very prevalent, and the other two examined HCV-related HCC in Japan. We identified a common variant in the DEPDC5 locus associated with HCV-related HCC, and another group identified an association involving the MICA locus. In this review, we compare the results of these GWAS and earlier candidate gene studies. Further research is needed to determine the role of these single nucleotide polymorphisms on HCC risk, but identification of these markers could make it possible to assess the magnitude of the risk of cancer based on each patient's genetic background. Consideration of the genetic background of the patients will likely play a role in personalized medicine for HCC, and understanding the mechanism underlying the association could suggest novel promising therapeutic targets in the future.

Serum PAI-1 is a novel predictor for response to pegylated interferon-α-2b plus ribavirin therapy in chronic hepatitis C virus infection

Obesity and insulin resistance have been reported as negative predictors for sustained virological response (SVR) in hepatitis C virus (HCV) genotype 1 infected patients treated with pegylated interferon-α plus ribavirin. They are also known to affect serum levels of several cytokines including adipocytokines. But the association between these cytokines and treatment outcome has not been fully elucidated. We examined pretreatment serum levels of 14 cytokines among 190 patients who were treated with pegylated interferon-α-2b plus ribavirin for chronic HCV-1b infection with high viral load (≥ 5 log IU/mL) and analyzed their contribution to treatment response. Plasminogen activator inhibitor-1 (PAI-1), vascular endothelial growth factor, and 11 clinical factors showed significant association with SVR in univariate logistic regression analysis. Four significant factors in multivariate analysis; serum PAI-1 (odds ratio [OR] = 15.42), body mass index (OR = 4.56), rs8099917 (OR = 4.95) and fibrosis stage (OR = 5.18) were identified as independent predictors. We constructed a simple and minimally invasive prediction score for SVR based on the presence of these factors except for fibrosis stage. The accuracy of this score was 73%, and was confirmed using an independent validation cohort consisting of 31 patients (68%). The strongest correlation was between PAI-1 level and platelet count (r = 0.38, P = 1.8 × 10(-7)), and PAI-1 level was inversely correlated with fibrosis stage. Serum PAI-1 is a novel predictor for the response to combination therapy against chronic HCV-1b infection and may be associated with liver fibrosis.

Host interleukin-28B genetic variants versus viral kinetics in determining responses to standard-of-care for Asians with hepatitis C genotype 1

BACKGROUND

Both interleukin-28B genetic variants and on-treatment virological responses are factors predictive of treatment outcome in hepatitis C virus genotype 1 (HCV-1) patients. We aimed to compare the clinical significance of the two factors.

METHODS

Rs8099917 genotype and on-treatment responses were determined in 182 HCV-1 patients with 48-week peginterferon/ribavirin.

RESULTS

Comparing to patients with rs8099917 TG/GG genotype, those with TT genotype had significantly higher rapid virological response (RVR, 46.2% vs. 19.2%, P=0.01) and sustained virological response (SVR, 85.3% vs. 42.3%, P<0.001) rates. Logistic regression analysis revealed that the strongest factor predictive of a RVR was the carriage of rs8099917 TT genotype (odds ratio/95% confidence intervals [OR/CI]: 4.25/1.39-13.01). The most important factor predictive of an SVR was the attainment of a RVR (OR/CI: 57.22/6.23-525.37), followed by the carriage of rs8099917 TT genotype (OR/CI: 10.06/3.12-32.44). However, while on-treatment factors were taken into account, the cEVR was the most important determinant to an SVR (OR/CI:54.98/9.07-333.38), whereas the influence of rs8099917 genotype became non-significant in non-RVR patients.

CONCLUSIONS

Rs8099917 TT genotype is significantly independently predictive of on-treatment virological responses, which were the major determinants of an SVR, in Asian HCV-1 patients.

Cholesterol and chronic hepatitis C virus infection

Cholesterol is an essential molecule for the life cycle of the hepatitis C virus (HCV). This review focuses on the roles of cholesterol in HCV infection and introduces HCV events related to cholesterol metabolism and applications for cholesterol metabolism as a therapeutic target. HCV appears to alter host lipid metabolism into its preferable state, which is clinically recognized as steatosis and hypocholesterolemia. While hepatic fatty acid and triglyceride syntheses are upregulated in chronic hepatitis C patients, no direct evidence of increased hepatic de novo cholesterol biosynthesis has been obtained. Impaired VLDL secretion from hepatocytes is suggested to increase intracellular cholesterol concentrations, which may lead to hypocholesterolemia. Clinically, lower serum cholesterol levels are associated with lower rates of sustained virological responses (SVR) to pegylated-interferon plus ribavirin therapy, but the reason remains unclear. Clinical trials targeting HMG-CoA reductase, the rate-limiting enzyme in the cholesterol biosynthetic pathway, are being conducted using statins. Anti-HCV actions by statins appear to be caused by the inhibition of geranylgeranyl pyrophosphate synthesis rather than their cholesterol lowering effects. Other compounds that block various steps of cholesterol metabolic pathways have also been studied to develop new strategies for the complete eradication of this virus.

Impact of ribavirin dose reduction on the efficacy of pegylated interferon plus ribavirin combination therapy for elderly patients infected with genotype 1b and high viral loads

AIM

  To examine the impact of ribavirin dose reduction on the efficacy of pegylated interferon (PEG IFN) plus ribavirin combination therapy for elderly patients infected with genotype 1b and high viral loads.

METHODS

  A total of 72 patients, over 65 years old, were recruited for this study. Patients were divided into groups receiving either 600-800 mg of ribavirin according to bodyweight (Group 1, n = 36) or 400 mg of ribavirin (Group 2, n = 36) plus 1.5 µg/kg (range: 1.3-2.0 µg/kg) of PEG IFN-α-2b for 48 weeks.

RESULTS

  Total ribavirin doses were administrated at 9.80 ± 2.39 mg/kg per day (3.29 ± 0.80 g/kg) for Group 1 and 5.87 ± 1.82 mg/kg per day (1.97 ± 0.61 g/kg) for Group 2 (P < 0.001). According to the total clearance (CL/F) of ribavirin, 34 of 36 patients in Group 1 received over-doses of ribavirin. In contrast, numbers of those receiving equivalent doses of ribavirin were two of 36 patients in Group 1 and 36 of 36 patients in Group 2, respectively (P < 0.001). End-of-treatment response (ETR) rates were observed in 23 of 36 patients (63.9%) in the standard ribavirin dose protocol and in 23 of 36 patients (63.9%) in the reduction ribavirin dose protocol (NS). Sustained virological response (SVR) rates were observed in 11 of 36 patients (30.6%) in the standard ribavirin dose protocol, and in 13 of 36 patients (36.1%) in the reduced ribavirin dose protocol (NS).

CONCLUSION

  Reduction of ribavirin doses for elderly patients did not affect the outcome for the 48-week combination therapy.