Reinventing HCV Treatment: Past and Future Perspectives

Improving Access to High-Value, High-Cost Medicines: The Use of Subscription Models to Treat Hepatitis C Using Direct-Acting Antivirals in the United States

State payers may face financial incentives to restrict use of high-cost medications. Yet, restrictions on access to high-value medications may have deleterious effects on population health. Direct-acting antivirals (DAAs), available since 2013, can cure chronic infection with hepatitis C virus (HCV). With prices upward of $90,000 for a treatment course, states have struggled to ensure access to DAAs for Medicaid beneficiaries and the incarcerated, populations with a disproportionate share of HCV. Advance purchase commitments (APCs), wherein a payer commits to purchase a certain quantity of medications at lower prices, offer payers incentives to increase access to high-value medications while also offering companies guaranteed revenue. This article discusses the use of subscription models, a type of APC, to support increased access to high-value DAAs for treating HCV. First, the authors provide background information about HCV, its treatment, and state financing of prescription medications. They then review the implementation of HCV subscription models in two states, Louisiana and Washington, and the early evidence of their impact. The article discusses challenges to evaluating state-sponsored subscription models, and it concludes by discussing implications of subscription models that target DAAs and other high-value, high-cost medicines.

Seroprevalence, Genotyping, and Monitoring of Hepatitis C Viral Loads in Patients on Antivirals in Burkina Faso

Introduction

Hepatitis C virus (HCV) infection remains a major public health problem worldwide. In Burkina Faso, nearly 720,000 people are living with HCV, and each year about 900 people die from complications of cirrhosis or hepatocellular carcinoma. This study was planned to determine the HCV seroprevalence, characterize circulating genotypes, and monitor HCV viral loads in patients under treatment with antivirals.

Methods

A total of 4,124 individuals and 167 patients in the pre-therapy program were recruited. The “SD Bioline HCV” kit was used for rapid screening of anti-HCV antibodies. Viral load and genotyping were performed in 167 HCV patients on antivirals using the “Iontek HCV Quant” and “Iontek genotyping” kits.

Results

Prevalence of HCV was 1.65% (68/4,124), and the median viral load of participants was 5.37 log10/mL (1.32–7.67 log10/mL). Genotype 2 was predominant with a frequency of 86.23% (144/167) and appeared to be more active with higher viral load compared to 13.77% (23/167) for genotype 1 (p < 0.001). After 24 weeks of pan-genotypic direct-acting antivirals, such as sofosbuvir/daclatasvir and sofosbuvir/velpatasvir, the viral loads of all patients became undetectable.

Conclusion

The responses to antivirals by the circulating genotypes indicate that the results are very satisfactory. Therefore, the prevalence of HCV in the population can be reduced through identification of cases and treatment.

The design and statistical aspects of VIETNARMS: a strategic post-licensing trial of multiple oral direct-acting antiviral hepatitis C treatment strategies in Vietnam

BACKGROUND

Eliminating hepatitis C is hampered by the costs of direct-acting antiviral treatment and the need to treat hard-to-reach populations. Access could be widened by shortening or simplifying treatment, but limited research means it is unclear which approaches could achieve sufficiently high cure rates to be acceptable. We present the statistical aspects of a multi-arm trial designed to test multiple strategies simultaneously and a monitoring mechanism to detect and stop individual randomly assigned groups with unacceptably low cure rates quickly.

METHODS

The VIETNARMS trial will factorially randomly assign patients to two drug regimens, three treatment-shortening strategies or control, and adjunctive ribavirin or no adjunctive ribavirin with shortening strategies (14 randomly assigned groups). We will use Bayesian monitoring at interim analyses to detect and stop recruitment into unsuccessful strategies, defined by more than 0.95 posterior probability that the true cure rate is less than 90% for the individual randomly assigned group (non-comparative). Final comparisons will be non-inferiority for regimens (margin 5%) and strategies (margin 10%) and superiority for adjunctive ribavirin. Here, we tested the operating characteristics of the stopping guideline for individual randomly assigned groups, planned interim analysis timings and explored power at the final analysis.

RESULTS

A beta (4.5, 0.5) prior for the true cure rate produces less than 0.05 probability of incorrectly stopping an individual randomly assigned group with a true cure rate of more than 90%. Groups with very low cure rates (<60%) are very likely (>0.9 probability) to stop after about 25% of patients are recruited. Groups with moderately low cure rates (80%) are likely to stop (0.7 probability) before overall recruitment finishes. Interim analyses 7, 10, 13 and 18 months after recruitment commences provide good probabilities of stopping inferior individual randomly assigned groups. For an overall true cure rate of 95%, power is more than 90% to confirm non-inferiority in the regimen and strategy comparisons, regardless of the control cure rate, and to detect a 5% absolute difference in the ribavirin comparison.

CONCLUSIONS

The operating characteristics of the stopping guideline are appropriate, and interim analyses can be timed to detect individual randomly assigned groups that are highly likely to have suboptimal performance at various stages. Therefore, our design is suitable for evaluating treatment-shortening or -simplifying strategies.

TRIAL REGISTRATION

ISRCTN registry: ISRCTN61522291. Registered on 4 October 2019.

The Role of PD-1 in Acute and Chronic Infection

PD-1 as an immune checkpoint molecule down-regulates T cell activity during immune responses in order to prevent autoimmune tissue damage. In chronic infections or tumors, lasting antigen-exposure leads to permanent PD-1 expression that can limit immune-mediated clearance of pathogens or degenerated cells. Blocking PD-1 can enhance T cell function; in cancer treatment PD-1 blockade is already used as a successful therapy. However, the role of PD-1 expression and blocking in the context of acute and chronic infections is less defined. Building on its success in cancer therapy leads to the hypothesis that blocking PD-1 in infectious diseases is also beneficial in acute or chronic infections. This review will focus on the role of PD-1 expression in acute and chronic infections with virus, bacteria, and parasites, with a particular focus on recent studies regarding PD-1 blockade in infectious diseases.

Real life efficacy and safety of direct-acting antiviral therapy for treatment of patients infected with hepatitis C virus genotypes 1, 2 and 3 in northwest China

BACKGROUND

Regimens involving direct-acting antiviral agents (DAAs) are recommended for the treatment of infection with hepatitis C virus (HCV) genotypes 1, 2 and 3. But real-world data is still not enough, especially in Asia.

AIM

To investigate the efficacy and safety of DAA-based regimens in a real-life setting in China.

METHODS

This study included 366 patients infected with HCV genotypes 1, 2 and 3, with or without cirrhosis, who were observed between May 2015 and December 2018. They were treated with ledipasvir and sofosbuvir (SOF) (genotype 1) with or without ribavirin (RBV), SOF and RBV (genotype 2), or SOF and daclatasvir (genotype 3), with or without RBV, for 12 or more wk. The participants’ sustained virological responses (SVR) at post-treatment week 12 (SVR12) was the primary endpoint. The occurrence of adverse events and drug-drug interactions were recorded.

RESULTS

In the 366 patients, genotype 1 (59.0%) was the most common genotype, followed by genotypes 2 (34.4%) and 3 (6.6%). Liver cirrhosis was diagnosed in 154 (42.1%) patients. Fifty (13.7%) patients were treatment-experienced. Intention-to-treat analysis revealed that SVR12 was 86.3% (316/366). For modified intention-to-treat analysis, SVR12 was achieved in 96.6% of overall patients (316/327), 96.3% in patients with genotype 1, 97.5% in those with genotype 2, and 95.0% in those with genotype 3. Most of the treatment failures were due to lack of follow-up (3 cases had non-responses, 1 had virological breakthrough, 11 relapsed and 36 did not participate in the follow-up). There was no significant difference in SVR between different genotypes and liver statuses (P < 0.05). Patients with lower alanine aminotransferase levels at baseline who achieved an end of treatment response were more likely to achieve SVR12 (P < 0.05). High SVR was observed regardless of age, gender, liver status, alpha-fetoprotein, HCV RNA levels or history of antiviral therapy (P > 0.05 for all). The cumulative hepatocellular carcinoma occurrence and recurrence rate after using the DAAs was 0.9%. Most of the adverse events were mild. We found two cases of special adverse events. One case involved facial and bilateral lower extremity edema, and the other case showed an interesting change in lipid levels while on medication. No severe adverse events were noted.

CONCLUSION

The DAA-based regimens tested in this study have excellent effectiveness and safety in all patients infected with HCV genotypes 1, 2 and 3, including those with cirrhosis.

Hepatitis C Virus among Female Sex Workers: A Cross-Sectional Study Conducted along Rivers and Highways in the Amazon Region

Background: Previous studies found a high prevalence of pathogens among female sex workers (FSWs) in the Amazon region, and established their parenteral and sexual transmission. This study estimated the prevalence of hepatitis C virus (HCV) infection and associated risk factors, and the frequency of HCV genotypes and resistance-associated substitutions (RASs) in this vulnerable group. Methods: Distinct sampling methods were used to access 412 FSWs in cities and riverside communities in the Amazon region from 2015 to 2018. Three methods for HCV diagnosis were used to determine infection status. HCV genotypes and RASs were identified by sequencing and nucleotide fragment analysis. An association between HCV infection and exposure factors was determined by bivariate and multivariate analysis. Results: In total, 44 (10.7%) FSWs were exposed to HCV, and 32 (7.8%) of them had active infection. Nine socioeconomic characteristics and risky sexual behaviors were associated with HCV exposure, particularly unprotected sex and condom exemption for the clients who paid extra money. Genotype 1 (81.3%) and 3 (18.7%) were detected. The frequency of FSWs with RASs was 23.1% (6/26) for grazoprevir related to the occurrence of substitutions Y56F and S122G. Conclusions: HCV infection among FSWs is highly prevalent and dominated by genotype I. Urgent preventive and treatment measures are required to reduce HCV infection in FSWs and the general population.

Incidence of hepatocellular carcinoma among older Americans attributable to hepatitis C and hepatitis B: 2001 through 2013

BACKGROUND

In the United States, incidence and mortality rates of hepatocellular carcinoma (HCC) are increasing in older individuals. Chronic infection with hepatitis C virus (HCV) and hepatitis B virus (HBV) are important causes of HCC; however, the contribution of viral hepatitis to recent trends in HCC incidence among older Americans is unclear.

METHODS

Data from the Surveillance, Epidemiology, and End Results-Medicare linkage (SEER-Medicare) for the years 2001 through 2013 were used to identify HCC cases among individuals aged ≥66 years and Medicare files were used to assess the HCV and HBV status of these HCC cases. Age-standardized incidence rates of HCV-attributable, HBV-attributable, and HCV/HBV-unrelated HCC were estimated overall and by age group, sex, and race/ethnicity. The authors also calculated annual percent changes (APCs) in HCC incidence.

RESULTS

Between 2001 and 2013, a total of 15,300 HCC cases occurred in this population. Overall HCC rates increased 43% from 16.3 to 23.3 per 100,000 population (APC, 3.40% per year), whereas HCV-attributable HCC rates nearly doubled from 4.2 to 8.2 per 100,000 population (APC, 5.62% per year). HCC rates increased more slowly for HBV-attributable HCC (1.3 to 1.8 per 100,000 population; APC, 3.17% per year) and HCV/HBV-unrelated HCC (11.3 to 14.1 per 100,000 population; APC, 2.35% per year). The percentage of HCC cases with evidence of HCV infection increased from 25.7% in 2001 through 2004 to 32.3% in 2011 through 2013, whereas the percentage with HBV remained stable at 8%. In 2013, higher rates for both HCV-attributable and HBV-attributable HCC were noted among individuals aged 66 to 75 years, men, and individuals of Asian ancestry.

CONCLUSIONS

Among Americans aged ≥66 years, HCC rates increased rapidly between 2001 and 2013. Although HCV-attributable cases contributed substantially to this increase, rates of HBV-attributable and HCV/HBV-unrelated HCC also rose during this period.

Sofosbuvir/Velpatasvir/Voxilaprevir: A Review in Chronic Hepatitis C

A fixed-dose combination of the hepatitis C virus (HCV) NS5B polymerase inhibitor sofosbuvir, the HCV NS5A inhibitor velpatasvir and the HCV NS3/4A protease inhibitor voxilaprevir (sofosbuvir/velpatasvir/voxilaprevir; Vosevi^®) is approved in the EU for the treatment of chronic HCV genotype 1, 2, 3, 4, 5 or 6 infection in adults. In the phase III POLARIS trials, in patients who had HCV genotype 1-6 infection with or without compensated cirrhosis, overall rates of sustained virological response at 12 weeks post-treatment (SVR₁₂) with sofosbuvir/velpatasvir/voxilaprevir were high after 8 weeks of treatment in direct-acting antiviral (DAA)-naïve patients and 12 weeks of treatment in DAA-experienced patients. However, 8 weeks of sofosbuvir/velpatasvir/voxilaprevir was inferior to 12 weeks of sofosbuvir/velpatasvir in cirrhotic or non-cirrhotic DAA-naïve patients with HCV genotype 1, 2, 4, 5 or 6 infection and non-cirrhotic DAA-naïve patients with HCV genotype 3 infection, mostly due to an insufficient treatment period. Sofosbuvir/velpatasvir/voxilaprevir was generally well tolerated, with most adverse events being of mild or moderate intensity. The most common adverse events included headache, fatigue, nausea and diarrhoea. In conclusion, sofosbuvir/velpatasvir/voxilaprevir is an important and effective option for the treatment of HCV genotype 1-6 infection in adults, especially those who have previously failed a DAA therapy with or without an HCV NS5A inhibitor.

Retrospective Cohort Study: Ledipasvir-Sofosbuvir With/Without Ribavirin for Chronic Hepatitis C Post–Liver Transplant in a Real-World Population

Background: Liver damage caused by hepatitis C virus (HCV) is the number one indication for liver transplantation in the United States and Europe. Patients with a detectable HCV level at time of transplant will universally develop a recurrent infection, which can lead to increased morbidity and mortality. Objective: To assess the sustained virologic response rate post end-of-treatment (SVR) in HCV-infected, post–liver transplant patients at the University of Washington Medical Center (UWMC) treated with ledipasvir-sofosbuvir (LDV/SOF). Methods: This retrospective, cohort study of HCV-positive, genotype 1 or 4 infected, post–liver transplant patients treated with LDV/SOF was conducted at a large academic medical center affiliated clinic. Patients treated with 12 weeks of LDV/SOF with or without ribavirin were included in the 12-week group, and patients treated with 24 weeks of LDV/SOF without ribavirin were included in the 24-week group. Results: Twenty-nine patients with recurrent HCV post–liver transplant receiving 12 weeks of LDV/SOF with or without ribavirin and 32 patients receiving 24 weeks of LDV/SOF alone were assessed. SVR was achieved by 100% (29/29) of patients in the 12-week group and 100% (32/32) of patients in the 24-week group. Conclusion: Post–liver transplant patients at UWMC treated with LDV/SOF for recurrent HCV achieved high rates of SVR.

HIV and hepatitis C virus infections in Quebec's provincial detention centres: comparing prevalence and related risky behaviours between 2003 and 2014-2015

OBJECTIVES

To compare the prevalence of HIV, hepatitis C virus (HCV) infections, and related risky behaviours among inmates in Quebec's provincial prisons between 2003 and 2014-2015.

METHODS

Cross-sectional data were anonymously collected from May 2014 to March 2015 for men (n = 1315) and women (n = 250) and combined with data collected in 2003 to evaluate trends in the last decade. Participants completed a questionnaire and provided saliva samples. The data from the 2003 and 2014-2015 surveys were merged for statistical analysis.

RESULTS

HIV prevalence was stable between 2003 and 2014-2015 for men (2.4% vs. 1.8%, p = 0.4), whereas it decreased for women (8.8% vs. 0.8%, p < 0.001). HCV prevalence decreased between 2003 and 2014-2015 for both men (16.6% vs. 11.9%, p < 0.001) and women (29.2% vs. 19.2%, p = 0.02). HIV and HCV prevalence were higher among people who inject drugs (PWID), for both sexes and both studies. PWID-specific prevalence did not change between 2003 and 2014-2015, except for a decrease in HIV prevalence in PWID women. However, the proportion of prisoners reporting a history of injection drug use outside prison was lower in 2014-2015 than in 2003 for men (19.8% vs. 27.7%, p < 0.0001) and women (28.6% vs. 42.6%, p = 0.002).

CONCLUSION

The lower proportion of PWID inmates in 2014-2015 compared to 2003 explained in large part the decrease in HIV and HCV prevalence. Despite the decrease in prevalence, HIV and HCV infections among incarcerated individuals still represent a major public health problem due to the sizable increase of individuals in Quebec's correctional system over the same period.

The 5BSL3.2 Functional RNA Domain Connects Distant Regions in the Hepatitis C Virus Genome

Viral genomes are complexly folded entities that carry all the information required for the infective cycle. The nucleotide sequence of the RNA virus genome encodes proteins and functional information contained in discrete, highly conserved structural units. These so-called functional RNA domains play essential roles in the progression of infection, which requires their preservation from one generation to the next. Numerous functional RNA domains exist in the genome of the hepatitis C virus (HCV). Among them, the 5BSL3.2 domain in the cis-acting replication element (CRE) at the 3' end of the viral open reading frame has become of particular interest given its role in HCV RNA replication and as a regulator of viral protein synthesis. These functionalities are achieved via the establishment of a complex network of long-distance RNA-RNA contacts involving (at least as known to date) the highly conserved 3'X tail, the apical loop of domain IIId in the internal ribosome entry site, and/or the so-called Alt region upstream of the CRE. Changing contacts promotes the execution of different stages of the viral cycle. The 5BSL3.2 domain thus operates at the core of a system that governs the progression of HCV infection. This review summarizes our knowledge of the long-range RNA-RNA interaction network in the HCV genome, with special attention paid to the structural and functional consequences derived from the establishment of different contacts. The potential implications of such interactions in switching between the different stages of the viral cycle are discussed.

Avasimibe: A novel hepatitis C virus inhibitor that targets the assembly of infectious viral particles

Direct-acting antivirals (DAAs), which target hepatitis C virus (HCV) proteins, have exhibited impressive efficacy in the management of chronic hepatitis C. However, the concerns regarding high costs, drug resistance mutations and subsequent unexpected side effects still call for the development of host-targeting agents (HTAs) that target host factors involved in the viral life cycle and exhibit pan-genotypic antiviral activity. Given the close relationship between lipid metabolism and the HCV life cycle, we investigated the anti-HCV activity of a series of lipid-lowering drugs that have been approved by government administrations or proven safety in clinical trials. Our results showed that avasimibe, an inhibitor of acyl coenzyme A:cholesterol acyltransferase (ACAT), exhibited marked pan-genotypic inhibitory activity and superior inhibition against HCV when combined with DAAs. Moreover, avasimibe significantly impaired the assembly of infectious HCV virions. Mechanistic studies demonstrated that avasimibe induced downregulation of microsomal triglyceride transfer protein expression, resulting in reduced apolipoprotein E and apolipoprotein B secretion. Therefore, the pan-genotypic antiviral activity and clinically proven safety endow avasimibe exceptional potential as a candidate for combination therapy with DAAs. In addition, the discovery of the antiviral properties of ACAT inhibitors also suggests that inhibiting the synthesis of cholesteryl esters might be an additional target for the therapeutic intervention for chronic HCV infection.

Efficacy of a 3C-like protease inhibitor in treating various forms of acquired feline infectious peritonitis

Objectives

The safety and efficacy of the 3C-like protease inhibitor GC376 was tested on a cohort of client-owned cats with various forms of feline infectious peritonitis (FIP).

Methods

Twenty cats from 3.3–82 months of age (mean 10.4 months) with various forms of FIP were accepted into a field trial. Fourteen cats presented with wet or dry-to-wet FIP and six cats presented with dry FIP. GC376 was administered subcutaneously every 12 h at a dose of 15 mg/kg. Cats with neurologic signs were excluded from the study.

Results

Nineteen of 20 cats treated with GC376 regained outward health within 2 weeks of initial treatment. However, disease signs recurred 1–7 weeks after primary treatment and relapses and new cases were ultimately treated for a minimum of 12 weeks. Relapses no longer responsive to treatment occurred in 13 of these 19 cats within 1–7 weeks of initial or repeat treatment(s). Severe neurologic disease occurred in 8/13 cats that failed treatment and five cats had recurrences of abdominal lesions. At the time of writing, seven cats were in disease remission. Five kittens aged 3.3–4.4 months with wet FIP were treated for 12 weeks and have been in disease remission after stopping treatment and at the time of writing for 5–14 months (mean 11.2 months). A sixth kitten was in remission for 10 weeks after 12 weeks of treatment, relapsed and is responding to a second round of GC376. The seventh was a 6.8-year-old cat with only mesenteric lymph node involvement that went into remission after three relapses that required progressively longer repeat treatments over a 10 month period. Side effects of treatment included transient stinging upon injection and occasional foci of subcutaneous fibrosis and hair loss. There was retarded development and abnormal eruption of permanent teeth in cats treated before 16–18 weeks of age.

Conclusions and relevance

GC376 showed promise in treating cats with certain presentations of FIP and has opened the door to targeted antiviral drug therapy.

Resistance Mechanisms in Hepatitis C Virus: implications for Direct-Acting Antiviral Use

Multiple direct-acting antiviral (DAA)-based regimens are currently approved that provide one or more interferon-free treatment options for hepatitis C virus (HCV) genotypes (G) 1-6. The choice of a DAA regimen, duration of therapy, and use of ribavirin depends on multiple viral and host factors, including HCV genotype, the detection of resistance-associated amino acid (aa) substitutions (RASs), prior treatment experience, and presence of cirrhosis. In regard to viral factors that may guide the treatment choice, the most important is the infecting genotype because a number of DAAs are genotype-designed. The potency and the genetic barrier may also impact the choice of treatment. One important and debated possible virologic factor that may negatively influence the response to DAAs is the presence of baseline RASs. Baseline resistance testing is currently not routinely considered or recommended for initiating HCV treatment, due to the overall high response rates (sustained virological response >90%) obtained. Exceptions are patients infected by HCV G1a when initiating treatment with simeprevir and elbasvir/grazoprevir or in those with cirrhosis prior to daclatasvir/sofosbuvir treatment because of natural polymorphisms demonstrated in sites of resistance. On the basis of these observations, first-line strategies should be optimized to overcome treatment failure due to HCV resistance.

Efficacy of 8 Weeks of Sofosbuvir, Velpatasvir, and Voxilaprevir in Patients With Chronic HCV Infection: 2 Phase 3 Randomized Trials

BACKGROUND & AIMS

Patients with chronic hepatitis C virus (HCV) infection have high rates of sustained virologic response (SVR) after 12 weeks of treatment with the nucleotide polymerase inhibitor sofosbuvir combined with the NS5A inhibitor velpatasvir. We assessed the efficacy of 8 weeks of treatment with sofosbuvir and velpatasvir plus the pangenotypic NS3/4A protease inhibitor voxilaprevir (sofosbuvir-velpatasvir-voxilaprevir).

METHODS

In 2 phase 3, open-label trials, patients with HCV infection who had not been treated previously with a direct-acting antiviral agent were assigned randomly to groups given sofosbuvir-velpatasvir-voxilaprevir for 8 weeks or sofosbuvir-velpatasvir for 12 weeks. POLARIS-2, which enrolled patients infected with all HCV genotypes with or without cirrhosis, except patients with genotype 3 and cirrhosis, was designed to test the noninferiority of 8 weeks of sofosbuvir-velpatasvir-voxilaprevir to 12 weeks of sofosbuvir-velpatasvir using a noninferiority margin of 5%. POLARIS-3, which enrolled patients infected with HCV genotype 3 who had cirrhosis, compared rates of SVR in both groups with a performance goal of 83%.

RESULTS

In POLARIS-2, 95% (95% confidence interval [CI], 93%-97%) of patients had an SVR to 8 weeks of sofosbuvir-velpatasvir-voxilaprevir; this did not meet the criterion to establish noninferiority to 12 weeks of sofosbuvir-velpatasvir, which produced an SVR in 98% of patients (95% CI, 96%-99%; difference in the stratum-adjusted Mantel-Haenszel proportions of -3.2%; 95% CI, -6.0% to -0.4%). The difference in the efficacy was owing primarily to a lower rate of SVR (92%) among patients with HCV genotype 1a infection receiving 8 weeks of sofosbuvir-velpatasvir-voxilaprevir. In POLARIS-3, 96% of patients (95% CI, 91%-99%) achieved an SVR in both treatment groups, which was significantly superior to the performance goal. Overall, the most common adverse events were headache, fatigue, diarrhea, and nausea; diarrhea and nausea were reported more frequently by patients receiving voxilaprevir. In both trials, the proportion of patients who discontinued treatment because of adverse events was low (range, 0%-1%).

CONCLUSIONS

In phase 3 trials of patients with HCV infection, we did not establish that sofosbuvir-velpatasvir-voxilaprevir for 8 weeks was noninferior to sofosbuvir-velpatasvir for 12 weeks, but the 2 regimens had similar rates of SVR in patients with HCV genotype 3 and cirrhosis. Mild gastrointestinal adverse events were associated with treatment regimens that included voxilaprevir. ClinicalTrials.gov numbers: POLARIS-2, NCT02607800; and POLARIS-3, NCT02639338.

Sofosbuvir-velpatasvir-voxilaprevir with or without ribavirin in direct-acting antiviral-experienced patients with genotype 1 hepatitis C virus

The optimal retreatment strategy for hepatitis C virus (HCV) genotype 1-infected patients who fail direct-acting antiviral (DAA)-based regimens remains unknown. In this phase 2, open-label study conducted at a single center in the United States, patients with HCV genotype 1 infection who previously failed to achieve sustained virological response (SVR) on a DAA-based regimen were randomized to receive treatment with a fixed-dose combination tablet of sofosbuvir-velpatasvir-voxilaprevir with or without ribavirin (RBV) for 12 weeks. Patients were stratified by their cirrhosis and past nonstructural protein (NS) 5A inhibitor exposure. The primary efficacy endpoint was the proportion of patients with SVR at 12 weeks after treatment (SVR12). SVR12 was achieved by 24 of 24 patients (100%; 95% confidence interval [CI], 86-100) receiving sofosbuvir-velpatasvir-voxilaprevir alone and 24 of 25 (96%; 95% CI, 80-100) receiving the same treatment with RBV. None of the patients discontinued sofosbuvir-velpatasvir-voxilaprevir therapy because of an adverse event (AE). The most commonly reported AEs with sofosbuvir-velpatasvir-voxilaprevir alone were diarrhea and bronchitis; and with sofosbuvir-velpatasvir-voxilaprevir plus RBV were fatigue, anemia, gastroenteritis, and nausea.

CONCLUSION

A fixed-dose combination of sofosbuvir-velpatasvir-voxilaprevir was well tolerated and effective at achieving virological response in patients with HCV genotype 1 infection and past DAA treatment experience. (Hepatology 2017;65:1803-1809).

Functional RNA structures throughout the Hepatitis C Virus genome

The single-stranded Hepatitis C Virus (HCV) genome adopts a set of elaborate RNA structures that are involved in every stage of the viral lifecycle. Recent advances in chemical probing, sequencing, and structural biology have facilitated analysis of RNA folding on a genome-wide scale, revealing novel structures and networks of interactions. These studies have underscored the active role played by RNA in every function of HCV and they open the door to new types of RNA-targeted therapeutics.