Interferon free hepatitis C treatment regimens: the beginning of another era

Does Hepatitis C Treatment Adherence Affect Risk of Liver Transplantation? A Historical Cohort Study

BACKGROUND

Chronic hepatitis C virus (HCV) is the primary cause of liver failure leading to transplantation, and medication adherence is essential to the therapeutic efficacy of HCV treatments. While there is evidence linking poor adherence with increased utilization and cost, published literature lacks examination of the association between medication adherence and risk of liver transplant. In addition, the impact of HCV treatment on total costs of liver transplantation is not well documented.

OBJECTIVES

To compare (a) the relative risk of liver transplant by adherence in patients treated for HCV and (b) the total health care costs in treated and untreated patients who require liver transplant.

METHODS

This observational, historical cohort study was conducted using administrative data from the Humana Research Database. To be included, patients were required to have a documented HCV diagnosis or treatment between January 1, 2008, and June 30, 2013. Patients were excluded if they had a hepatitis B diagnosis, were not fully insured by a commercial or Medicare Advantage Prescription Drug plan, or were outside the age range of 19-89 years. No minimum pre- or post-index enrollment period was required, and patients were followed for their entire post-index enrollment through December 31, 2013. The study population was divided into treated and untreated groups and then subdivided by presence or absence of a liver transplant. Date of liver transplant was defined as the index date for untreated liver transplant patients; otherwise, the index date was defined as either the date of first observed HCV treatment or diagnosis date (if no treatment or liver transplant). Cox proportional hazards models were used to estimate the relative risk of liver transplant by level of treatment adherence (> 80%, 50%-79%, and < 50%) based on proportion of days covered. General linearized models with log link and gamma distribution were used to compare median total health care costs from index date until end of study period (or death/disenrollment, whichever came first) between treated and untreated liver transplant patients. All costs were converted to 2013 U.S. dollars and reported as total costs per patient and per patient per month (PPPM) to account for varying follow-up periods.

RESULTS

Of the 53,423 patients identified with HCV, 10,377 met exclusion criteria, leaving 43,046 patients (primarily Caucasian, males, mean age of 58 years) in the initial cohort. Only 6.29% (n = 2,708) of the total HCV cohort received HCV treatment, and less than 1% (n = 366, 0.8%) received a liver transplant. Although there were no significant differences in the risk of liver transplant by adherence level, there was an upwards trend in the rate of liver transplant as adherence worsened (> 80%: 1.25%; 50%-79%: 1.30%; and < 50%: 1.99%), and the average days to liver transplant was longer with higher adherence (> 80%: 683; 50%-79%: 623; < 50%: 454). Only 48 (13.11%) patients who received a liver transplant were treated for HCV. Adjusted median total and PPPM health care costs measured from index date until end of the study period were significantly higher for patients who received HCV treatment compared with those who did not (total=$231,139 vs. $86,167, adjusted P < 0.001; PPPM=$20,583 vs. $5,778, adjusted P = 0.008), driven by HCV-related medical costs and total pharmacy costs.

CONCLUSIONS

Adherence with HCV regimens did not affect risk of liver transplant, underscoring the need for further evidence linking treatment adherence to future liver transplant risk. HCV-treated patients who required liver transplant incurred significantly higher health care costs than those without HCV treatment before liver transplant. Introduction of newer all-oral direct-acting antiviral regimens, with higher acquisition costs, will require further research to more accurately assess medication adherence and its relationship with transplantation, as well as with total health care costs.

DISCLOSURES

No outside funding supported this research. Ems, Worley, Racsa, Gregory, Anderson, and Holt are employees of Humana. Brill has participated in a physician advisory board at Humana. The authors have no other financial disclosures to report. Study concept and design were contributed by Ems, Racsa, Worley, and Anderson, along with Gregory, Brill, and Holt. Racsa took the lead in data collection, along with Ems and Worley. All authors participated in data interpretation. Anderson, along with the other authors, wrote the manuscript, which was revised by Brill and Holt, with assistance from the other authors.

Naturally occurring resistance mutations to inhibitors of HCV NS5A region and NS5B polymerase in DAA treatment-naïve patients

Background

Direct-acting antiviral (DAA) agents target HCV proteins; some of these have already been approved for the treatment of HCV infection, while others are in development. However, selection of DAA-resistant viral variants may hamper treatment. The aim of this study was to illustrate potential natural DAA-resistance mutations in the HCV NS5A and NS5B regions of HCV genotypes 1a and 1b from DAA-naïve patients.

Methods

Direct sequencing of HCV NS5A and NS5B regions was performed in 32 patients infected with HCV genotype 1a and 30 patients infected with HCV genotype 1b; all subjects were naïve to DAAs.

Results

In genotype 1a strains, resistance mutations in NS5A (M28V, L31M and H58P) were observed in 4/32 (12.5%) patients, and resistance mutations in NS5B (V321I, M426L, Y448H, Y452H) were observed in 4/32 (12.5%) patients. In genotype 1b, resistance mutations in NS5A (L28V, L31M, Q54H, Y93H and I280V) were observed in 16/30 (53.3%) patients, while resistance mutations in NS5B (L159F, V321I, C316N, M426L, Y452H, R465G and V499A) were observed in 27/30 (90%) patients.

Conclusions

Mutations conferring DAA resistance were detected in NS5A and NS5B of HCV genotypes 1a and 1b from DAA-naïve patients. Although some mutations confer only a low level of resistance, the presence at baseline of mutated HCV variants should be taken into consideration in the context of DAA therapy.

In vitro characterization of GSK2485852, a novel hepatitis C virus polymerase inhibitor

GSK2485852 (referred to here as GSK5852) is a hepatitis C virus (HCV) NS5B polymerase inhibitor with 50% effective concentrations (EC50s) in the low nanomolar range in the genotype 1 and 2 subgenomic replicon system as well as the infectious HCV cell culture system. We have characterized the antiviral activity of GSK5852 using chimeric replicon systems with NS5B genes from additional genotypes as well as NS5B sequences from clinical isolates of patients infected with HCV of genotypes 1a and 1b. The inhibitory activity of GSK5852 remained unchanged in these intergenotypic and intragenotypic replicon systems. GSK5852 furthermore displays an excellent resistance profile and shows a <5-fold potency loss across the clinically important NS5B resistance mutations P495L, M423T, C316Y, and Y448H. Testing of a diverse mutant panel also revealed a lack of cross-resistance against known resistance mutations in other viral proteins. Data from both the newer 454 sequencing method and traditional population sequencing showed a pattern of mutations arising in the NS5B RNA-dependent RNA polymerase in replicon cells exposed to GSK5852. GSK5852 was more potent than HCV-796, an earlier inhibitor in this class, and showed greater reductions in HCV RNA during long-term treatment of replicons. GSK5852 is similar to HCV-796 in its activity against multiple genotypes, but its superior resistance profile suggests that it could be an attractive component of an all-oral regimen for treating HCV.

Retreatment with peg-interferon and ribavirin in patients with chronic hepatitis C virus genotype 2 or 3 infection with prior relapse

OBJECTIVES

Uncertainty remains regarding the efficacy of retreatment with current standard-of-care peg-interferon (peg-IFN) and ribavirin among patients infected with hepatitis C virus (HCV) genotypes 2 or 3 with relapse after prior therapy.

MATERIALS AND METHODS

Seventy-one patients with chronic HCV genotype 2/3 with prior relapse were enrolled in a phase III multicenter study. Patients were retreated with peg-IFNα-2a 180 μg per week and ribavirin 1000/1200 mg daily. Patients having received previous therapy for 24 weeks were retreated for 48 weeks (Group A), whereas patients having received at least 12 weeks but less than 24 weeks of treatment were allocated to either 48 (Group B) or 24 weeks (Group C) on the basis of whether they had achieved rapid virological response (RVR).

RESULTS

Sustained virological response (SVR) rates of 53%, 81% and 75% were achieved in groups A, B and C, respectively. Patients with favorable baseline characteristics, e.g., less advanced liver fibrosis, age <40 years, duration of infection <20 years, or BMI < 25 kg/m(2), tended to have more favorable outcomes. All patients achieving HCV RNA below 1000 IU/mL day 6 achieved SVR in contrast to none of the patients with detectable HCV RNA at week 12.

CONCLUSIONS

Retreatment with peg-IFN and ribavirin for 24-48 weeks entails SVR among the majority of HCV genotype 2/3 infected patients with prior relapse. However, in light of the prolonged treatment duration, moderate effect and considerable side effects, deterring therapy until new options are available may be preferential, particularly in patients previously treated for 24 weeks.

Hepatitis C virus treatment and liver transplantation in the era of new antiviral therapies

PURPOSE OF REVIEW

The new standard-of-care treatment for genotype 1 hepatitis C virus infection is a combination of PEG-interferon (PEG-IFN), ribavirin (RBV) and a protease inhibitor - telaprevir or boceprevir. As triple therapy is not yet approved for use in decompensated cirrhotics and liver transplant recipients, we examine the efficacy and safety of PEG-IFN, RBV and protease inhibitors in nontransplant populations to inform the current and future treatment paradigms for transplant candidates and recipients.

RECENT FINDINGS

Protease inhibitor-based triple therapy is more efficacious than PEG-IFN and RBV in nontransplant genotype 1 patients, so sustained virologic response rates are predicted to be higher in waitlisted candidates and transplant recipients treated with protease inhibitor-triple therapy. Because of the need to use a backbone of PEG-IFN and RBV, tolerability of therapy will remain a major challenge. Anemia, a well recognized side-effect with PEG-IFN and RBV, will be especially common with protease inhibitor-triple therapy. Both protease inhibitors can modify the levels of drugs metabolized by the CYP3A/4 pathway, and in posttransplant patients, the protease inhibitors increase the levels of cyclosporine and tacrolimus, with the magnitude of the drug-drug interactions varying with protease inhibitor and type of calcineurin inhibitor (CNI).

SUMMARY

Given the complexities of treatment, it is best undertaken by experienced clinicians and only after a detailed discussion of risks-benefits with the patient. To maximize the benefit while minimizing risk, only Child-Turcott-Pugh A (CPT-A) cirrhotics should be considered for pretransplant protease inhibitor-triple therapy. For transplant recipients, very close monitoring and adjustment of CNI levels is critical during protease inhibitor-triple therapy. Cytopenias, especially anemia, will require aggressive management.

Physical, social, and psychological consequences of treatment for hepatitis C : a community-based evaluation of patient-reported outcomes

BACKGROUND

Hepatitis C virus (HCV) antiviral therapy entails a long treatment course, as well as significant side effects that can lead to medication non-adherence and premature termination of treatment. Few large studies have comprehensively examined patient perspectives on the treatment experience, particularly the social and personal effects.

OBJECTIVE

We sought to understand how a diverse group of patients' lives were affected during HCV treatment, and to obtain suggestions about how to better support patients during treatment.

METHODS

On average, 13 months after therapy we interviewed by telephone a consecutive sample of 200 patients treated for hepatitis C with ribavirin and pegylated interferon in a comprehensive, integrated health plan in the years 2008-2010. Mixed (quantitative and qualitative) survey methods were used.

RESULTS

The response rate was 68.9 %. Mean age at treatment was 51 years; 63.0 % were men; and Black, Hispanic, Asian, and White non-Hispanic racial/ethnic groups were similarly represented. Patients whose treatment was managed by nurses or clinical pharmacists (vs. physicians) were more likely to report their providers as being part of their support system (83.5 % vs. 58.9 %; p < 0.001). Most patients reported flu-like symptoms (93.5 %) and psychiatric problems (84.5 %), and 42.5 % reported side effects lasted up to 6 months after treatment. Black patients reported discontinuing treatment prematurely due to side effects more often than non-Blacks (29.4 % vs. 12.1 %; p < 0.001). Physical side effects (69.5 % of patients), psychiatric issues (43.5 %), and employment (27.4 %) were ranked among the three most difficult challenges. Patients desired help in anticipating and arranging work modifications during treatment. Most patients rated peer support, nutritional guidance, and weekly provider contact by telephone as potentially helpful resources for future patients undergoing HCV treatment.

CONCLUSIONS

Patient perspectives can help formulate and refine HCV treatment support programs. Effective support programs for diverse populations are crucial as the complexities and costs of HCV treatment increase. The call for greater support from peers, providers, and employers demands new systems such as patient-centered care teams.

The future developments in hepatology: no need for a jaundiced view

There have been major advances in the diagnosis and management of all forms of liver disease since the British Society of Gastroenterology first came into existence 75 years ago. In this review some of the exciting developments that are likely to enter into routine clinical practice over the next 5 years are highlighted. It is suggested that some critical changes need to take place in UK hepatology over the next decade to ensure that the management of liver disease in this country continues to be among the best in the world.