Hepatitis C Virus (HCV) Direct-Acting Antiviral Therapy in Persons With Human Immunodeficiency Virus-HCV Genotype 1 Coinfection Resulting in High Rate of Sustained Virologic Response and Variable in Normalization of Soluble Markers of Immune Activation.

BACKGROUND: Hepatitis C virus (HCV) direct-acting antivirals are highly effective. Less is known about changes in markers of immune activation in persons with human immunodeficiency virus (HIV) in whom a sustained virologic response (SVR) is achieved. METHODS: We conducted a nonrandomized clinical trial of 12 or 24 weeks of paritaprevir-ritonavir-ombitasvir plus dasabuvir (PrOD) with or without ribavirin in persons with HCV-1/HIV coinfection suppressed with antiretroviral therapy. Plasma HCV, soluble CD14 (sCD14), interferon-inducible protein 10, soluble CD163 (sCD163), interleukin 6 (IL-6), interleukin 18, monocyte chemoattractant protein (MCP-1), autotaxin (ATX), and Mac2-binding protein (Mac2BP) were measured over 48 weeks. RESULTS: Participants were treated with PrOD for 12 (n = 9) or 24 (n = 36) weeks; the SVR rate at 12 weeks was 93%. At baseline, cirrhosis was associated with higher ATX and MCP-1, female sex with higher ATX and IL-6, older age with higher Mac2BP, higher body mass index with higher ATX, and HIV-1 protease inhibitor use with higher sCD14 levels. In those with SVR, interferon-inducible protein 10, ATX, and Mac2BP levels declined by week 2, interleukin 18 levels declined by the end of treatment, sCD14 levels did not change, and sCD163, MCP-1, and IL-6 levels changed at a single time point. CONCLUSIONS: During HIV/HCV coinfection, plasma immune activation marker heterogeneity is in part attributable to age, sex, cirrhosis, body mass index, and/or type of antiretroviral therapy. HCV treatment with paritaprevir-ritonavir-ombitasvir plus dasabuvir is highly effective and is associated with variable rate and magnitude of decline in markers of immune activation. CLINICAL TRIALS REGISTRATION: NCT02194998.

Intrahepatic Viral Kinetics During Direct-Acting Antivirals for Hepatitis C in Human Immunodeficiency Virus Coinfection: The AIDS Clinical Trials Group A5335S Substudy.

BACKGROUND: Direct-acting antivirals (DAAs) targeting hepatitis C virus (HCV) have revolutionized outcomes in human immunodeficiency virus (HIV) coinfection. METHODS: We examined early events in liver and plasma through A5335S, a substudy of trial A5329 (paritaprevir/ritonavir, ombitasvir, dasabuvir, with ribavirin) that enrolled chronic genotype 1a HCV-infected persons coinfected with suppressed HIV: 5 of 6 treatment-naive enrollees completed A5335S. RESULTS: Mean baseline plasma HCV ribonucleic acid (RNA) = 6.7 log10 IU/mL and changed by -4.1 log10 IU/mL by Day 7. In liver, laser capture microdissection was used to quantify HCV. At liver biopsy 1, mean %HCV-infected cells = 25.2% (95% confidence interval [CI], 7.4%-42.9%), correlating with plasma HCV RNA (Spearman rank correlation r = 0.9); at biopsy 2 (Day 7 in 4 of 5 participants), mean %HCV-infected cells = 1.0% (95% CI, 0.2%-1.7%) (P < .05 for change), and DAAs were detectable in liver. Plasma C-X-C motif chemokine 10 (CXCL10) concentrations changed by mean = -160 pg/mL per day at 24 hours, but no further after Day 4. CONCLUSIONS: We conclude that HCV infection is rapidly cleared from liver with DAA leaving <2% HCV-infected hepatocytes at Day 7. We extrapolate that HCV eradication could occur in these participants by 63 days, although immune activation might persist. Single-cell longitudinal estimates of HCV clearance from liver have never been reported previously and could be applied to estimating the minimum treatment duration required for HCV infection.

Pharmacokinetics and renal safety of tenofovir alafenamide with boosted protease inhibitors and ledipasvir/sofosbuvir.

BACKGROUND: Ledipasvir/sofosbuvir increases tenofovir plasma exposures by up to 98% with tenofovir disoproxil fumarate (TDF), and exposures are highest with boosted PIs. There are currently no data on the combined use of the newer tenofovir prodrug, tenofovir alafenamide (TAF), boosted PIs and ledipasvir/sofosbuvir. OBJECTIVES: To compare the plasma and intracellular pharmacokinetics and renal safety of TAF with ledipasvir/sofosbuvir when co-administered with boosted PIs. METHODS: Persons with HIV between 18 and 70 years and on a boosted PI with TDF were eligible. The study was comprised of four phases: (1) TDF 300 mg with boosted PI; (2) TAF 25 mg with boosted PI; (3) TAF 25 mg with boosted PI and ledipasvir/sofosbuvir; and (4) TAF 25 mg with boosted PI. Pharmacokinetic sampling, urine biomarker collection [urine protein (UPCR), retinol binding protein (RBP) and ß2 microglobulin (ß2M) normalized to creatinine] and safety assessments occurred at the end of each phase. Plasma, PBMCs and dried blood spots were collected at each visit. RESULTS: Ten participants were enrolled. Plasma tenofovir exposures were 76% lower and tenofovir-diphosphate (TFV-DP) concentrations in PBMCs increased 9.9-fold following the switch to TAF. Neither of these measures significantly increased with ledipasvir/sofosbuvir co-administration, nor did TAF plasma concentrations. No significant changes in estimated glomerular filtration rate or UPCR occurred, but RBP:creatinine and ß2M:creatinine improved following the switch to TAF. CONCLUSIONS: Ledipasvir/sofosbuvir did not significantly increase plasma tenofovir or intracellular TFV-DP in PBMCs with TAF. These findings provide reassurance that the combination of TAF, boosted PIs and ledipasvir/sofosbuvir is safe in HIV/HCV-coinfected populations.

Raltegravir pharmacokinetics before and during treatment with ombitasvir, paritaprevir/ritonavir plus dasabuvir in adults with human immunodeficiency virus-1 and hepatitis C virus coinfection: AIDS Clinical Trials Group sub-study A5334s.

AIMS: AIDS Clinical Trials Group study A5334s evaluated the pharmacokinetics of raltegravir before and during combined administration of ombitasvir, paritaprevir/ritonavir, plus dasabuvir (OBV/PTV/r + DSV) and weight-based ribavirin in human immunodeficiency virus (HIV) and hepatitis C virus (HCV) coinfected adults. The pharmacokinetics of OBV/PTV/r + DSV during raltegravir coadministration were also characterized. METHODS: Adults living with HIV/HCV coinfection receiving steady-state raltegravir (400 mg twice daily) with 2 nucleos(t)ide analogues were enrolled. Pharmacokinetics of raltegravir were assessed prior to HCV therapy, and 4 weeks later following initiation of OBV/PTV/r (25/150/100 mg) once daily + DSV (250 mg) twice daily. Geometric mean ratios (GMRs) and 90% confidence intervals (CIs) were used to compare the following: raltegravir pharmacokinetics with HCV therapy (week 4) vs before HCV therapy (week 0); OBV/PTV/r and DSV pharmacokinetics vs historical healthy controls; raltegravir pharmacokinetics at week 0 vs historical control adults living with HIV. RESULTS: Eight of 11 participants had decreased raltegravir exposures after initiation of HCV therapy. The GMRs (90% CI) for maximum concentration and area under the concentration-time curve of raltegravir with vs without HCV therapy were 0.68 (0.38-1.19) and 0.82 (0.58-1.17), respectively. Comparing OBV/PTV/r pharmacokinetics in healthy controls, A5334s study participants demonstrated generally lower maximum concentration and area under the concentration-time curve values by 41-82% and 4-73%, respectively. Raltegravir exposures tended to be higher in A5334s study participants compared to adults living with HIV. CONCLUSIONS: The majority of participants' plasma raltegravir exposures were lower after initiation of HCV therapy in coinfected adults; however, confidence intervals were wide.

Glecaprevir/Pibrentasvir in patients with chronic HCV genotype 3 infection: An integrated phase 2/3 analysis.

Glecaprevir coformulated with pibrentasvir (G/P) is approved to treat hepatitis C virus (HCV) infection and was highly efficacious in phase 2 and 3 studies. Treating HCV genotype (GT) 3 infection remains a priority, as these patients are harder to cure and at a greater risk for liver steatosis, fibrosis progression and hepatocellular carcinoma. Data were pooled from five phase 2 or 3 trials that evaluated 8-, 12- and 16-week G/P in patients with chronic HCV GT3 infection. Patients without cirrhosis or with compensated cirrhosis were either treatment-naïve or experienced with interferon- or sofosbuvir-based regimens. Safety and sustained virologic response 12 weeks post-treatment (SVR12) were assessed. The analysis included 693 patients with GT3 infection. SVR12 was achieved by 95% of treatment-naïve patients without cirrhosis receiving 8-week (198/208) and 12-week (280/294) G/P. Treatment-naïve patients with cirrhosis had a 97% (67/69) SVR12 rate with 12-week G/P. Treatment-experienced, noncirrhotic patients had SVR12 rates of 90% (44/49) and 95% (21/22) with 12- and 16-week G/P, respectively; 94% (48/51) of treatment-experienced patients with cirrhosis treated for 16 weeks achieved SVR12. No serious adverse events (AEs) were attributed to G/P; AEs leading to study drug discontinuation were rare (<1%). G/P was well-tolerated and efficacious for patients with chronic HCV GT3 infection, regardless of cirrhosis status or prior treatment experience. Eight- and 12-week durations were efficacious for treatment-naïve patients without cirrhosis and with compensated cirrhosis, respectively; 16-week G/P was efficacious in patients with prior treatment experience irrespective of cirrhosis status.

Daclatasvir plus Sofosbuvir for HCV in Patients Coinfected with HIV-1.

BACKGROUND: The combination of daclatasvir, a hepatitis C virus (HCV) NS5A inhibitor, and the NS5B inhibitor sofosbuvir has shown efficacy in patients with HCV monoinfection. Data are lacking on the efficacy and safety of this combination in patients coinfected with human immunodeficiency virus type 1 (HIV-1). METHODS: This was an open-label study involving 151 patients who had not received HCV treatment and 52 previously treated patients, all of whom were coinfected with HIV-1. Previously untreated patients were randomly assigned in a 2:1 ratio to receive either 12 weeks or 8 weeks of daclatasvir at a standard dose of 60 mg daily (with dose adjustment for concomitant antiretroviral medications) plus 400 mg of sofosbuvir daily. Previously treated patients were assigned to undergo 12 weeks of therapy at the same doses. The primary end point was a sustained virologic response at week 12 after the end of therapy among previously untreated patients with HCV genotype 1 who were treated for 12 weeks. RESULTS: Patients had HCV genotypes 1 through 4 (83% with genotype 1), and 14% had compensated cirrhosis; 98% were receiving antiretroviral therapy. Among patients with genotype 1, a sustained virologic response was reported in 96.4% (95% confidence interval [CI], 89.8 to 99.2) who were treated for 12 weeks and in 75.6% (95% CI, 59.7 to 87.6) who were treated for 8 weeks among previously untreated patients and in 97.7% (95% CI, 88.0 to 99.9) who were treated for 12 weeks among previously treated patients. Rates of sustained virologic response across all genotypes were 97.0% (95% CI, 91.6 to 99.4), 76.0% (95% CI, 61.8 to 86.9), and 98.1% (95% CI, 89.7 to 100), respectively. The most common adverse events were fatigue, nausea, and headache. There were no study-drug discontinuations because of adverse events. HIV-1 suppression was not compromised. CONCLUSIONS: Among previously untreated HIV-HCV coinfected patients receiving daclatasvir plus sofosbuvir for HCV infection, the rate of sustained virologic response across all genotypes was 97.0% after 12 weeks of treatment and 76.0% after 8 weeks. (Funded by Bristol-Myers Squibb; ALLY-2 ClinicalTrials.gov number, NCT02032888.).

Glecaprevir and pibrentasvir yield high response rates in patients with HCV genotype 1-6 without cirrhosis.

BACKGROUND & AIMS: Hepatitis C virus (HCV) therapy that is highly efficacious, pangenotypic, with a high barrier to resistance and short treatment duration is desirable. The efficacy and safety of 8- and 12-week treatments with glecaprevir (ABT-493; NS3/4A protease inhibitor) and pibrentasvir (ABT-530; NS5A inhibitor) were evaluated in non-cirrhotic patients with chronic HCV genotype 1-6 infection. METHODS: SURVEYOR-I and SURVEYOR-II were phase II, open-label, multicenter, dose-ranging trials including patients with chronic HCV genotype 1-6 infection who were either previously untreated or treated with pegylated interferon plus ribavirin. Patients received once-daily glecaprevir plus pibrentasvir at varying doses with or without ribavirin for 8 or 12weeks. The primary efficacy endpoint was the percentage of patients with a sustained virologic response at post-treatment week 12 (SVR12). RESULTS: Of the 449 patients who received varying doses of glecaprevir plus pibrentasvir, 25%, 29%, 39%, and 8% had HCV genotype 1, 2, 3, and 4-6 infection, respectively. Twelve-week treatment achieved SVR12 in 97-100%, 96-100%, 83-94%, and 100% in genotypes 1, 2, 3, and 4-6, respectively. Eight-week treatment with 300mg glecaprevir plus 120mg pibrentasvir in genotype 1-, 2-, or 3-infected patients yielded 97-98% SVR12 with no virologic failures. Three (0.7%) patients discontinued treatment due to adverse events; most events were mild (grade 1) in severity. No post-nadir alanine aminotransferase elevations were observed. CONCLUSIONS: Glecaprevir plus pibrentasvir was well tolerated and achieved high sustained virologic response rates in HCV genotypes 1-6-infected patients without cirrhosis following 8- or 12-week treatment durations. LAY SUMMARY: The combination of direct-acting antivirals glecaprevir and pibrentasvir comprise a once-daily, all-oral, pangenotypic treatment for HCV genotype 1-6 infection. This article describes results from two phase II trials investigating a range of doses at treatment durations of 8 or 12weeks in 449 patients without cirrhosis. Efficacy of the optimal dose, as determined by rates of sustained virologic response at post-treatment week 12, ranged from 92%-100%; treatment was well tolerated and significant laboratory abnormalities were rare. CLINICAL TRIAL REGISTRATION: clinicaltrials.gov Identifiers: NCT02243280 and NCT02243293. http://www.clinicaltrials.gov/show/NCT02243280, http://www.clinicaltrials.gov/show/NCT01939197.

High Efficacy of ABT-493 and ABT-530 Treatment in Patients With HCV Genotype 1 or 3 Infection and Compensated Cirrhosis.

BACKGROUND & AIMS: The combination of ABT-493 (NS3/4A protease inhibitor) plus ABT-530 (NS5A inhibitor) has shown high rates of sustained virologic response at post-treatment week 12 (SVR12) in noncirrhotic patients infected with hepatitis C virus (HCV) genotypes (GTs) 1-6. We describe 2 open-label phase 2 studies investigating the efficacy and safety of ABT-493 plus ABT-530 with or without ribavirin (RBV) in GT1- or GT3-infected patients with compensated cirrhosis. METHODS: Patients with GT1 infection received 200 mg ABT-493 plus 120 mg ABT-530 for 12 weeks. Patients with GT3 infection were randomized 1:1 to receive 300 mg ABT-493 plus 120 mg ABT-530 with or without once-daily 800 mg RBV for 12 weeks; treatment-experienced patients who were not treated with RBV received 16 weeks of therapy. Efficacy was measured by SVR12, defined as an HCV-RNA level less than 25 IU/mL. Adverse events and laboratory parameters were evaluated throughout the study. RESULTS: Twenty-seven patients with GT1 infection and 55 patients with GT3 infection were enrolled. The majority were treatment-naive (84%) and male (65%). In patients with GT1 infection, SVR12 was achieved by 96% (26 of 27; 95% confidence interval [CI], 82-99) of patients, with 1 relapse. Among GT3-infected patients, SVR12 was achieved in 96% (27 of 28; 95% CI, 82-99) of patients in the RBV-free arm (1 relapse), and in 100% (27 of 27; 95% CI, 88-100) in the RBV-containing arm. The most common adverse events were headache, fatigue, and nausea. Laboratory abnormalities were rare; no patient discontinued treatment. CONCLUSIONS: In cirrhotic HCV GT1- or GT3-infected patients, ABT-493 plus ABT-530 with or without RBV achieved SVR12 rates of 96%-100% and was well tolerated. ClinicalTrials.gov identifiers NCT02243280 and NCT02243293.

Resistance to DAAs: When to Look and When It Matters.

PURPOSE OF REVIEW: This review provides an overview of HCV resistance-associated substitutions (RASs) with a focus on NS3 protease and NS5A inhibitor resistance. Treatment approaches for managing resistance are also covered including the use of newly approved therapies with improved resistance profiles. RECENT FINDINGS: HCV RASs are frequently selected if the patient is not cured during treatment; NS5A RASs persist for prolonged periods of time (years) after treatment failure and may adversely impact retreatment responses. Newly approved regimens with improved potency and resistance profiles are less impacted by resistance and provide the best retreatment options for patients who previously failed DAA therapy. The clinical impact of HCV RASs has been lessened significantly with the introduction of new DAA treatment regimens. Routine testing for resistance is unlikely to impact retreatment approaches if newer regimens are accessible. Knowledge of factors, such as the presence of cirrhosis and prior treatment regimens, remain as the key to optimizing retreatment approaches.

Functional conservation despite structural divergence in ligand-responsive RNA switches.

An internal ribosome entry site (IRES) initiates protein synthesis in RNA viruses, including the hepatitis C virus (HCV). We have discovered ligand-responsive conformational switches in viral IRES elements. Modular RNA motifs of greatly distinct sequence and local secondary structure have been found to serve as functionally conserved switches involved in viral IRES-driven translation and may be captured by identical cognate ligands. The RNA motifs described here constitute a new paradigm for ligand-captured switches that differ from metabolite-sensing riboswitches with regard to their small size, as well as the intrinsic stability and structural definition of the constitutive conformational states. These viral RNA modules represent the simplest form of ligand-responsive mechanical switches in nucleic acids.

Management of Hepatitis C/HIV Coinfection in the Era of Highly Effective Hepatitis C Virus Direct-Acting Antiviral Therapy.

The increased life expectancy of persons infected with human immunodeficiency virus (HIV) treated with antiretroviral therapy (ART) has resulted in renewed attention to non-HIV-related diseases exacerbated by HIV infection. Coinfection with hepatitis C virus (HCV) is a particular area of concern, as the global prevalence has been estimated at 2.5-5 million people. In this article, we discuss the epidemiology of HCV infection and reinfection, HCV-related liver disease progression in the era of effective ART, and the efficacy of emerging HCV treatment strategies in persons with HIV/HCV coinfection. New data regarding treatment of persons with HIV/HCV coinfection suggest that HCV treatment should be a priority in those with HIV. Results from recent studies using all-oral HCV regimens have shown high rates of sustained virologic response in both clinical trials and real-world settings. A multidisciplinary approach to HCV treatment in those with HIV is recommended for optimal patient management. Following HCV cure, practitioners also need to be mindful of the risks for HCV reinfection and educate patients on protective measures.

Temporal dynamics of inflammatory cytokines/chemokines during sofosbuvir and ribavirin therapy for genotype 2 and 3 hepatitis C infection.

UNLABELLED: The analysis of inflammatory cytokines and chemokines produced during hepatitis C virus (HCV) infection has advanced our understanding of viral-host interactions and identified predictors of treatment response. Administration of interferons (IFNs) made it difficult to interpret biomarkers of immune activation during treatment. Direct-acting antiviral (DAA) regimens without IFN are now being used to treat HCV with excellent efficacy. To gain insight into HCV-host interactions occurring before, during, and after HCV treatment, we performed a case-control study that measured serial plasma levels of IFN-γ-inducible protein 10 (IP-10), monocyte chemoattractant protein 1 (MCP-1), macrophage inflammatory protein 1 beta (MIP-1ß), and interleukin-18 (IL-18) in 131 patients with chronic HCV treated with sofosbuvir (SOF) plus ribavirin (RBV). A linear regression analysis using baseline factors identified strong positive associations between elevated alanine aminotransferase and pretreatment IP-10 and between the presence of cirrhosis and elevated pretreatment IL-18. Mean IP-10, MCP-1, MIP-1ß, and IL-18 levels all decline on therapy, but display different dynamics late in treatment and after cessation of therapy. On treatment, IP-10 and MIP-1ß levels were significantly higher in individuals who achieved sustained virological response (SVR). Logistic regression analyses examining treatment response in all patients demonstrated significant associations between higher baseline MIP-1ß levels and smaller decreases in MIP-1ß early in treatment and SVR. Higher early MIP-1ß levels were also significantly associated with SVR in subsets of patients with cirrhosis and individuals with genotype 3 (GT3) infection, two factors associated with decreased responsiveness to treatment. CONCLUSION: Changes in IP-10 levels mirror HCV RNA, suggesting that IP-10 is an indicator of innate immune viral recognition. MIP-1ß levels remain elevated in GT2/3 patients who achieved SVR, suggesting differential immune activation in those who respond to SOF/RBV therapy and a potential role in predicting treatment responses.

Sofosbuvir With Velpatasvir in Treatment-Naive Noncirrhotic Patients With Genotype 1 to 6 Hepatitis C Virus Infection: A Randomized Trial.

BACKGROUND: Effective, pangenotypic treatments for hepatitis C virus (HCV) infection are needed. OBJECTIVE: To assess the safety and efficacy of sofosbuvir with velpatasvir in patients infected with HCV genotypes 1 to 6. DESIGN: Randomized, phase 2, open-label study. (ClinicalTrials.gov: NCT01858766). SETTING: 48 U.S. sites. PATIENTS: 377 treatment-naive noncirrhotic patients. In part A, patients infected with HCV genotypes 1 to 6 were randomly assigned to sofosbuvir, 400 mg, with velpatasvir, 25 or 100 mg, for 12 weeks. In part B, patients with genotype 1 or 2 HCV infection were randomly assigned to sofosbuvir, 400 mg, and velpatasvir, 25 or 100 mg, with or without ribavirin for 8 weeks. MEASUREMENTS: Sustained virologic response at 12 weeks (SVR12). RESULTS: In part A, SVR12 rates were 96% (26 of 27) with velpatasvir, 25 mg, and 100% (28 of 28) with velpatasvir, 100 mg, for genotype 1; 93% (25 of 27) in both groups for genotype 3; and 96% (22 of 23) with velpatasvir, 25 mg, and 95% (21 of 22) with velpatasvir, 100 mg, for genotypes 2, 4, 5, and 6. In part B, for genotype 1, SVR12 rates were 87% (26 of 30) with velpatasvir, 25 mg; 83% (25 of 30) with velpatasvir, 25 mg, plus ribavirin; 90% (26 of 29) with velpatasvir, 100 mg; and 81% (25 of 31) with velpatasvir, 100 mg, plus ribavirin. For genotype 2, SVR12 rates were 77% (20 of 26) with velpatasvir, 25 mg; 88% (22 of 25) with velpatasvir, 25 mg, plus ribavirin; 88% (23 of 26) with velpatasvir, 100 mg; and 88% (23 of 26) with velpatasvir, 100 mg, plus ribavirin. Adverse events included fatigue (21%), headache (20%), and nausea (12%). One patient committed suicide. LIMITATION: The study was open-label, no inferential statistics were planned, and sample sizes were small. CONCLUSION: Twelve weeks of sofosbuvir, 400 mg, and velpatasvir, 100 mg, was well-tolerated and resulted in high SVR in patients infected with HCV genotypes 1 to 6. PRIMARY FUNDING SOURCE: Gilead Sciences.

All-oral combination of ledipasvir, vedroprevir, tegobuvir, and ribavirin in treatment-naïve patients with genotype 1 HCV infection.

UNLABELLED: This phase II trial assessed the efficacy and safety of a combination regimen of the nonstructural protein (NS)5A inhibitor ledipasvir (LDV), NS3 protease inhibitor vedroprevir (VDV), non-nucleoside NS5B inhibitor tegobuvir (TGV), and ribavirin (RBV) in treatment-naïve patients with chronic hepatitis C virus (HCV) genotype 1 without cirrhosis. Patients were randomized 1:2 to LDV 30 mg once daily (QD; Arm 1; n = 46) or LDV 90 mg QD (Arm 2; n = 94); patients in both arms also received VDV 200 mg QD, TGV 30 mg twice-daily, and RBV 1,000-1,200 mg/day. Patients in Arm 2 with vRVR, defined as HCV RNA below the lower limit of quantification (LLOQ) from treatment weeks 2 to 10, were randomized 1:1 to stop treatment at 12 weeks or continue for 24 weeks. Sustained virologic response 12 weeks after treatment (SVR12) was higher in patients receiving 90 mg of LDV for 24 weeks (63%), compared with LDV 90 mg for 12 weeks (54%) and LDV 30 mg for 24 weeks (48%). In patients with very rapid virologic response (vRVR) in Arm 2, SVR12 was achieved by 68% and 81% of patients treated for 12 and 24 weeks, respectively. Virologic breakthrough was more common in patients with HCV genotype 1a and was associated with resistance-associated variants for all three direct-acting antiviral agents (DAAs); however, in all but 1 patient who relapsed, resistance-associated variants directed against only one or two of the DAAs were detected. The most common adverse events were fatigue, headache, nausea, rash, and diarrhea. CONCLUSION: In patients with HCV genotype 1, an interferon-free regimen containing LDV/VDV/TGV/RBV was well tolerated and led to SVR12 in up to 63% of patients. LDV 90 mg is currently being investigated in combination with the nucleotide polymerase inhibitor, sofosbuvir.

Structure of a hepatitis C virus RNA domain in complex with a translation inhibitor reveals a binding mode reminiscent of riboswitches.

The internal ribosome entry site (IRES) in the hepatitis C virus (HCV) RNA genome is essential for the initiation of viral protein synthesis. IRES domains adopt well-defined folds that are potential targets for antiviral translation inhibitors. We have determined the three-dimensional structure of the IRES subdomain IIa in complex with a benzimidazole translation inhibitor at 2.2 Å resolution. Comparison to the structure of the unbound RNA in conjunction with studies of inhibitor binding to the target in solution demonstrate that the RNA undergoes a dramatic ligand-induced conformational adaptation to form a deep pocket that resembles the substrate binding sites in riboswitches. The presence of a well-defined ligand-binding pocket within the highly conserved IRES subdomain IIa holds promise for the development of unique anti-HCV drugs with a high barrier to resistance.

Interferon γ-induced protein 10 kinetics in treatment-naive versus treatment-experienced patients receiving interferon-free therapy for hepatitis C virus infection: implications for the innate immune response.

We measured interferon γ-induced protein 10 (IP-10) levels in 428 patients at baseline, week 1, and week 2 of all-oral treatment for hepatitis C virus (HCV) infection. An increased baseline IP-10 level was associated with a T allele in the IL28B gene, an increased alanine aminotransferase level in treatment-naive but not experienced patients, and an increased body mass index. At week 1, the mean decline in plasma IP-10 levels was the same in treatment-naive and treatment-experienced patients (-49%), whereas during week 2 the mean decline in IP-10 levels in treatment-naive patients (-14%) was significantly larger than in treatment-experienced patients (-2%; P = .0176). IP-10 thus may be a surrogate marker of the rate of intracellular viral replication complex decay.

Infrequent development of resistance in genotype 1-6 hepatitis C virus-infected subjects treated with sofosbuvir in phase 2 and 3 clinical trials.

BACKGROUND: Sofosbuvir is a chain-terminating nucleotide analogue inhibitor of the hepatitis C virus (HCV) NS5B RNA polymerase that is efficacious in subjects with HCV genotype 1-6 infection. Sofosbuvir resistance is primarily conferred by the S282T substitution in NS5B. METHODS: NS5B sequencing and susceptibility testing of HCV from subjects infected with genotypes 1-6 who participated in phase 2 and 3 sofosbuvir clinical trials was performed. RESULTS: No NS5B variants present at baseline among 1645 sofosbuvir-treated subjects were associated with treatment failure; sofosbuvir susceptibility was within 2-fold of reference. Among 282 subjects who did not achieve sustained virologic response, no novel sofosbuvir resistance-associated variants were identified, and the NS5B changes observed did not confer significant reductions in sofosbuvir susceptibility. In 1 subject with S282T observed at relapse 4 weeks after sofosbuvir monotherapy, the resistant variant (13.5-fold reduced sofosbuvir susceptibility, replication capacity <2% of control) became undetectable by deep sequencing 12 weeks after treatment. L159F and V321A were identified as treatment-emergent variants but did not confer resistance to sofosbuvir in the replicon system. CONCLUSIONS: These data demonstrate a uniform susceptibility of subject-derived HCV to sofosbuvir, and also show that selection of sofosbuvir-resistant HCV is exceedingly rare and is associated with a significant reduction in viral fitness.

Early identification and linkage to care of persons with chronic hepatitis B virus infection--three U.S. sites, 2012-2014.

In the United States, an estimated 0.8-1.4 million persons are living with chronic hepatitis B virus (HBV) infection. Among these persons, as many as 70% were born in countries of Asia, Africa, or other regions where HBV is moderately or highly endemic (hepatitis B surface antigen [HBsAg] prevalence ≥2%). HBV-associated cirrhosis and liver cancer are major health problems for these populations. Most persons with HBV were infected at birth or during early childhood and are asymptomatic until advanced liver disease develops. To address these concerns, CDC recommends HBsAg testing for all persons born in these areas and linkage to medical care and preventive services for those who are infected. In 2012, CDC awarded funds to nine sites to implement this recommendation. This report describes programs at three sites (New York, New York; Minneapolis-St. Paul, Minnesota; and San Diego, California) that conducted HBV testing, in clinical or community settings, and referred for medical evaluation and care those persons whose HBsAg test results were positive. During October 2012-March 2014, the three sites tested 4,727 persons for HBV infection; 310 (6.6%) were HBsAg-positive. Among the HBsAg-positive persons, 94% were informed of their results, 90% were counseled, 86% were referred for care, and 66% attended their scheduled first medical visit. These projects demonstrate that community-based programs can identify infected persons among populations with a high prevalence of HBV infection and refer HBsAg-positive persons for care. Individualized efforts to assist patients with accessing and receiving health-care services ("patient navigation services") can increase the number of persons who follow up on referrals and receive recommended care.