RNA Decline Research Articles

Modelling hepatitis C therapy--predicting effects of treatment.

Mathematically modelling changes in HCV RNA levels measured in patients who receive antiviral therapy has yielded many insights into the pathogenesis and effects of treatment on the virus. By determining how rapidly HCV is cleared when viral replication is interrupted by a therapy, one can deduce how rapidly the virus is produced in patients before treatment. This knowledge, coupled with estimates of the HCV mutation rate, enables one to estimate the frequency with which drug resistant variants arise. Modelling HCV also permits the deduction of the effectiveness of an antiviral agent at blocking HCV replication from the magnitude of the initial viral decline. One can also estimate the lifespan of an HCV-infected cell from the slope of the subsequent viral decline and determine the duration of therapy needed to cure infection. The original understanding of HCV RNA decline under interferon-based therapies obtained by modelling needed to be revised in order to interpret the HCV RNA decline kinetics seen when using direct-acting antiviral agents (DAAs). There also exist unresolved issues involving understanding therapies with combinations of DAAs, such as the presence of detectable HCV RNA at the end of therapy in patients who nonetheless have a sustained virologic response.

Modelling the interaction between danoprevir and mericitabine in the treatment of chronic HCV infection.

Modelling HCV RNA decline kinetics under therapy has proven useful for characterizing treatment effectiveness. Here we model HCV viral kinetics (VK) in 72 patients given a combination of danoprevir, a protease inhibitor, and mericitabine, a nucleoside polymerase inhibitor, for 14 days in the INFORM-1 trial. A biphasic VK model with time-varying danoprevir and mericitabine effectiveness and Bliss independence for characterizing the interaction between both drugs provided the best fit to the VK data. The average final antiviral effectiveness of the drug combination varied between 0.998 for 100 mg three times daily of danoprevir and 500 mg twice daily of mericitabine and 0.9998 for 600 mg twice daily of danoprevir and 1,000 mg twice daily of mericitabine. Using the individual parameters estimated from the VK data collected over 2 weeks, we were not able to reproduce the low sustained virological response rates obtained in a more recent study where patients were treated with a combination of mericitabine and ritonavir-boosted danoprevir for 24 weeks. This suggests that drug-resistant viruses emerge after 2 weeks of treatment and that longer studies are necessary to provide accurate predictions of longer treatment outcomes.

P0858 : Early HCV RNA decline by baseline characteristics in HCV infected patients receiving sofosbuvir-based treatment: An Italian single center experience

P0858 : Early HCV RNA decline by baseline characteristics in HCV infected patients receiving sofosbuvir-based treatment: An Italian single center experience

Efficacy of Generic Highly Active Antiretroviral Therapy in HIV-1 Infected Individuals in Nigeria

CD4 T lymphocyte and plasma HIV RNA parameters have been used to monitor disease progression, and predict clinical course in HIV infection. Initial evaluation of these parameters was conducted in the western countries where accessible ARVs, circulating HIV subtypes and mode of transmission are different from the situation in Nigeria. This study appraised these parameters, and efficacy of generic ARVs. Consenting 106 HIV infected ARV naïve patients were enrolled. CD4 T lymphocyte and plasma HIV RNA levels were determined at interval for 24 months. Ninety eight (92.5%) of the patients who completed the follow up in strict adherence to therapy guideline were included in the analysis. Baseline median CD4 T lymphocyte increased from 114 (Range: 6–330) to highest 357 (Range: 15–1036) cells/μL at 18 months of therapy, while baseline median plasma viral RNA declined from 4.6 (Range: 2.6–6.0) Log10 copies/mL to undetectable level within three months of therapy. Significant CD4 T-cell restoration and plasma viral RNA decline in the study population demonstrate efficacy of the generic HAART. The importance of combined use of both parameters for evaluation of immunologic and virologic responses to ART was confirmed.

Pretreatment serum macrophage inflammatory protein (MIP)-1 levels predict sustained virological responses to re-treatment in patients with chronic hepatitis C virus infection

There are few predictors of the virological response in patients who are re-treated with antiviral therapies. In this study, we evaluated the levels of chemokines that bind to C-C chemokine receptor type 5 (CCR5) and their impact on combination therapy in both treatment-naïve and treatment-experienced patients chronically infected with hepatitis C virus (HCV). Longitudinal analysis of CCR5 chemokines was performed using the multiplex Bio-Rad 27-plex assay in 56 treatment-naïve and 24 treatment-experienced patients with chronic HCV infection during combination therapy with peginterferon alfa and ribavirin. A group of healthy donors was included as the control (n=11). The pretreatment level of macrophage inflammatory protein 1 (MIP-1) was determined to be an independent predictor, with an ideal predictive threshold for sustained virological response of 95.23 pg/ml. A rapid decline in HCV RNA was observed in patients with a pretreatment MIP-1 level of <95.23 pg/ml, while a slow reduction was measured in patients with levels of ≥95.23 pg/ml (p=0.014). Of note, the dynamics of MIP-1 further indicated that a lower level at baseline and at treatment week 12 was significantly associated with a favorable outcome of antiviral therapy (p=0.014), especially in treatment-experienced patients (p=0.04), while a higher level of MIP-1beta correlated with the elevation of transaminases. Serum MIP-1 is an independent and effective predictor of early and sustained virological response in chronically HCV-infected patients undergoing re-treatment.

Spontaneous pharyngeal Chlamydia trachomatis RNA clearance. A cross-sectional study followed by a cohort study of untreated STI clinic patients in Amsterdam, The Netherlands

ObjectivesPharyngeal Chlamydia trachomatis (chlamydia) might contribute to ongoing chlamydia transmission, yet data on spontaneous clearance duration are rare. We examined the prevalence, spontaneous clearance, chlamydial DNA concentration and genotypes of...

Efficacy of lead‐in silibinin and subsequent triple therapy in difficult‐to‐treat HIV/hepatitis C virus‐coinfected patients

The efficacy of current hepatitis C virus (HCV) triple therapy, including a protease inhibitor, is limited in HIV/HCV-coinfected patients with advanced liver fibrosis and nonresponse to previous peginterferon-ribavirin. These patients have a low chance (only 30%) of achieving a sustained virological response (SVR) during triple therapy and cannot wait for next-generation anti-HCV drugs. In a pilot study, we investigated the efficacy of a lead-in therapy with silibinin before triple therapy in difficult-to-treat patients. Inclusion criteria were HIV/HCV coinfection with advanced liver fibrosis and documented failure of previous peginterferon-ribavirin treatment. Intervention was lead-in therapy with intravenous silibinin 20 mg/kg/day for 14 days. Subsequently, peginterferon-ribavirin combined with telaprevir was initiated for 12 weeks, followed by peginterferon-ribavirin dual therapy until week 48 after initiation of triple therapy. The outcome measurements were HCV RNA after silibinin lead-in, at weeks 2, 4 and 12 of triple therapy, and SVR at week 24 after the end of treatment. We examined six HIV/HCV-coinfected patients (four infected with genotype 1a). All had fibrosis grade METAVIR ≥F3 and were on fully suppressive antiretroviral therapy. Mean HCV RNA decline after silibinin therapy was 2.6 log10 IU/mL (range 2-3 log10 IU/mL). Five of the six patients were virologically suppressed at weeks 2 and 4, and all six at week 12 of triple therapy. One experienced a viral breakthrough thereafter. Four of five patients (80%) showed an SVR 24. One patient had an SVR 12 but has not yet reached week 24. A lead-in with silibinin before triple therapy is highly effective and increases the probability of HCV treatment success in difficult-to-treat HIV/HCV-coinfected patients with advanced liver fibrosis and previous failure of peginterferon-ribavirin.

Randomized, placebo-controlled, single-ascending-dose study of BMS-791325, a hepatitis C virus (HCV) NS5B polymerase inhibitor, in HCV genotype 1 infection.

BMS-791325 is a nonnucleoside inhibitor of hepatitis C virus (HCV) NS5B polymerase with low-nanomolar potency against genotypes 1a (50% effective concentration [EC50], 3 nM) and 1b (EC50, 7 nM) in vitro. BMS-791325 safety, pharmacokinetics, and antiviral activity were evaluated in a double-blind, placebo-controlled, single-ascending-dose study in 24 patients (interferon naive and experienced) with chronic HCV genotype 1 infection, randomized (5:1) to receive a single dose of BMS-791325 (100, 300, 600, or 900 mg) or placebo. The prevalence and phenotype of HCV variants at baseline and specific posttreatment time points were assessed. Antiviral activity was observed in all cohorts, with a mean HCV RNA decline of ≈2.5 log10 copies/ml observed 24 h after a single 300-mg dose. Mean plasma half-life among cohorts was 7 to 9 h; individual 24-hour levels exceeded the protein-adjusted EC90 for genotype 1 at all doses. BMS-791325 was generally well tolerated, with no serious adverse events or discontinuations. Enrichment for resistance variants was not observed at 100 to 600 mg. At 900 mg, variants (P495L/S) associated with BMS-791325 resistance in vitro were transiently observed in one patient, concurrent with an observed HCV RNA decline of 3.4 log10 IU/ml, but were replaced with wild type by 48 h. Single doses of BMS-791325 were well tolerated; demonstrated rapid, substantial, and exposure-related antiviral activity; displayed dose-related increases in exposure; and showed viral kinetic and pharmacokinetic profiles supportive of once- or twice-daily dosing. These results support its further development in combination with other direct-acting antivirals for HCV genotype 1 infection. (This trial has been registered at ClinicalTrials.gov under registration no. NCT00664625.).

Virological response to short-course maraviroc monotherapy does not predict viral tropism in HIV-1-infected treatment-naive patients

We aimed to evaluate whether virological response to a short course of maraviroc monotherapy could predict HIV-1 tropism. A clinical trial was performed in HIV-1 treatment-naive patients infected with R5- or non-R5-tropic virus determined using the Trofile(®) assay, with >1000 HIV-1 RNA copies/mL. Maraviroc was administered for 10 days. Viral load was measured at baseline and days 4, 7, 10 and 28. The main outcome measurement was the decline in HIV-1 RNA at day 10. The trial was registered in the ClinicalTrials.gov database (NCT01060618; TROPISMVC). Forty patients [30 R5 and 10 dual/mixed (D/M)] were recruited. There was a significant decrease in HIV-1 RNA after 10 days of maraviroc treatment in patients with R5-tropic virus (median 1.52 log10 RNA copies/mL; 95% CI 1.23-1.63; P < 0.0001), but also in patients with D/M-tropic virus (median 1.62 log(10) RNA copies/mL; 95% CI 0.33-1.88; P = 0.00024). The difference in the HIV-1 RNA decrease (-0.16 log(10) RNA copies/mL; 95% CI -0.53 to 0.22) was not significant (P = 0.410). A decrease >0.5 log(10) RNA copies/mL was found in 96.3% of patients with R5-tropic virus and in 70% of patients with D/M-tropic virus (P = 0.052). The differences were not significant when a decline of 1 log(10) RNA copies/mL was considered (92.6% versus 70%; P = 0.11). Treatment-naive patients infected with R5- or D/M-tropic virus have similar virological responses to a short course of maraviroc monotherapy. This clinical test thus cannot be used as a surrogate marker of viral tropism in this population.

Early predictors of antiviral treatment response in liver transplant recipients with recurrent hepatitis C genotype 1

The success of current antiviral treatment for hepatitis C virus (HCV) recurrence in liver transplant (LT) recipients remains limited. We aimed at evaluating the value of IL28B genotype and early viral kinetics to predict response to standard treatment in the transplant setting. We retrospectively evaluated 104 LT recipients treated for HCV genotype 1 recurrence between 2001 and 2010. Baseline variables, including IL28B genotype, and early viral kinetics were compared among patients who did or did not achieve a sustained virological response (SVR). Logistic regression analyses of candidate variables were conducted to generate a reliable predictive model based on the minimum set of variables. Twenty-nine (28%) achieved an SVR. On multivariate analysis, the magnitude of HCV RNA decline at 4 weeks (OR: 3.74, 95% CI: 1.64-9.39; P = 0.003) and treatment compliance (OR: 35.27, 95% CI: 3.35-365.54; P = 0.003) were the only independent predictors of SVR. Favourable recipient IL28B genotype significantly correlates with virological response at week 4 (OR 3.23; 95% CI, 1.12-9.15; P = 0.03). By logistic regression analysis, a model including donor age, recipient rs12979860 genotype and viral load at 4 weeks showed the best predictive value for SVR with an area under the receiver operating curve of 0.861. Favourable recipient IL28B genotype strongly correlates with the viral response at week 4 which is the strongest predictor of response. The combination of recipient IL28B genotype and donor age with the week 4 response reliably estimates the probability of SVR early on-treatment and may facilitate therapeutic strategies incorporating new antiviral agents.

Effect of scavenger receptor B-I antagonist, ITX5061, on early hepatitis C virus kinetics in liver transplantation: results of a phase 1b clinical trial

BackgroundPrevention of recurrent hepatitis C virus (HCV) infection after liver transplantation is a major unmet clinical need. ITX5061 is a small molecule antagonist of scavenger receptor B-I that prevents HCV entry and infection in vitro. The aim of this phase 1 study was to determine safety and efficacy of ITX5061 to prevent HCV allograft infection. MethodsIn this phase 1b single-centre, prospective, open-label study, we included 23 consecutive patients with HCV infection (21 male) undergoing liver transplantation. The first 13 patients did not receive study drug (controls). The subsequent ten patients received ITX5061 150 mg orally immediately before liver transplantation, after transplantation, and daily for 1 week. Plasma HCV RNA was measured at 13 predefined time-points during the first week and weekly thereafter for the first month, allowing detailed viral kinetic monitoring. Plasma samples were collected to determine ITX5061 before and after transplantation and measured with liquid chromatography and mass spectrometry. This trial is registered with ClinicalTrials.gov, number NCT01292824. Findings13 recipients were infected with HCV genotype 1. There was no significant difference between untreated and treated patients at baseline and all patients survived 1 month after liver transplantation. ITX5061 treatment was well tolerated with no difference in the nature or frequency of adverse events between the treated and untreated patients. Oral absorption of ITX5061 was demonstrated, with measurable plasma concentrations before transplatation and daily for 1 week after transplantation. HCV RNA concentrations decreased during the first 24 h but remained detectable for all patients at all times during treatment and follow-up. Compared with values measured during the anhepatic phase of surgery, the median reduction in HCV RNA was greater for treated patients at all timepoints (∼ 1 log10 difference during 7 days' treatment). The maximum decline in HCV RNA was greater than 2 log10 in eight of ten treated patients compared with six of 13 untreated patients. In patients with genotype 1 disease (n=6), treatment was associated with a sustained reduction in HCV RNA titre (all >2 log10) during 7 days compared with the control group (n=7), none of whom achieved a 2 log10 reduction at any time. After withdrawal of treatment, HCV RNA increased in all patients. InterpretationOur findings show that treatment with ITX5061, an inhibitor of HCV entry, is safe and well tolerated in liver transplantation. ITX5061 affects plasma HCV RNA kinetics, and a substantial reduction in plasma HCV RNA during treatment was recorded. These findings support further investigation into the efficacy of ITX5061 in HCV- infected patients undergoing liver transplantation. FundingiTherX, Inc., NIHR Birmingham Liver Biomedical Research Unit.

Analysis of Hepatitis C Viral Kinetics during Administration of Two Nucleotide Analogues: Sofosbuvir (Gs-7977) and Gs-0938

Sofosbuvir (GS-7977) and GS-0938 are nucleotide analogue HCV polymerase inhibitors, with sofosbuvir being a pyrimidine and GS-0938 being a purine. Mathematical modelling has provided important insights for characterizing HCV RNA decline and for estimating the in vivo effectiveness of single direct-acting antiviral agents (DAAs); however it has not been used to characterize viral kinetics with combination DAA therapy. We evaluated the antiviral activity of sofosbuvir and GS-0938 given alone and in combination for 14 days in 32 HCV genotype 1 treatment-naive patients (P2938-0212; NUCLEAR study). Viral load declined rapidly in a biphasic manner in all subjects and could be well fitted by assuming that both drugs had a similar and additive level of effectiveness in reducing viral production equal to 99.96%, on average. The model predicted that this level of effectiveness was not reached until 0.6 and 2 days for GS-0938 and sofosbuvir, respectively, and likely represents the time needed to accumulate intracellular triphosphates. Subsequently, both drugs led to a rapid second phase of viral decline with a mean rate of 0.35 d(-1). No effect of IL28B-polymorphism was found on viral kinetic parameters. Both sofosbuvir and GS-0938 are highly effective at blocking viral production from HCV-infected cells. Both drugs led to a rapid and consistent second phase viral decline and exhibited no breakthroughs or other signs of resistance. From a kinetics perspective, because both drugs were of the same class there was little benefit in combining them, suggesting that future DAA combinations should consider utilizing drugs with different modes of action.

Lymphocytes Degranulation in Liver in Hepatitis C Virus Carriers Is Associated With IFNL4 Polymorphisms and ALT Levels

The polymorphisms of IFNL4 are strongly associated with both spontaneous hepatitis C virus (HCV) clearance and response to peg-IFN-α/ribavirin treatment. To further establish the biological effects of the IFNL4 and rs1297860 variations, we studied the activity of liver immune cells. Fresh liver samples were collected from HCV-infected patients before any treatment and from NASH patients as controls. Degranulation activity of each lymphocyte type was assessed by the surface expression of CD107a. IFNL4 polymorphisms and HCV genotypes were determined. In the liver, frequency of CD107a(+) immune cells was significantly higher in HCV patients compared to NASH patients. Higher degranulation activity was observed in lymphocytes of HCV patients with favorable IFNL4 genotypes compared to patients with unfavorable genotypes. Multivariate regression analyses indicated that serum ALT levels were dependent on both Metavir activity score and frequency of CD107a positive NKT cells. The high level of degranulation activity observed before treatment was associated with a high HCV RNA decline at the early stage of peg-IFN-α/ribavirin treatment in patients with favorable genotypes. These data underline that intrahepatic lymphocyte degranulation activity in HCV-infected patients is associated with IFNL4 polymorphisms and contributes to the clearance of HCV in patients with favorable genotypes under antiviral therapy.

Patterns of viral load decline with telaprevir-based therapy in patients with genotype 1 chronic HCV infection

BackgroundTelaprevir-based therapy is associated with rapid decline in HCV RNA, enabling the application of early futility rules. ObjectivesTo familiarize physicians with this paradigm, a comprehensive analysis of the most frequent HCV viral load profiles observed during treatment with telaprevir/Peg-IFN/RBV in Phase III trials is provided. DesignHCV RNA profiles were analyzed from 320 HCV genotype 1 treatment-naïve patients enrolled in the ADVANCE study, and 225 prior Peg-IFN/RBV treatment-experienced patients enrolled in the REALIZE study. Patients received 12 weeks of telaprevir with either 24 or 48 weeks of Peg-IFN alfa-2a/RBV. Patients with missing SVR assessments during follow-up, detectable HCV RNA at end of treatment but who did not have viral breakthrough (vBT), or with early vBT who discontinued telaprevir before time of failure were excluded. ResultsAll analyzed patients experienced a rapid decline in HCV RNA (>2.0 log10) by Day 14, irrespective of baseline characteristics and/or prior response to Peg-IFN/RBV (relapse, partial response and null response). Subsequently, HCV RNA continued to decline to undetectable levels in most patients. These patients went on to have one of the following outcomes: sustained virologic response, late vBT (after Week 12, i.e. during the Peg-IFN/RBV phase), or relapse. In the small subset of patients with early vBT or meeting a futility rule before Week 12, HCV RNA usually never became undetectable and/or increased rapidly after reaching the nadir. ConclusionsHCV RNA profiles with telaprevir/Peg-IFN/RBV are different from those with Peg-IFN/RBV alone. It is important that clinicians understand these HCV RNA profiles and monitor patient viral load in order to apply futility rules correctly.

Boceprevir is highly effective in treatment-experienced hepatitis C virus-positive genotype-1 menopausal women.

To investigate the safety/efficacy of Boceprevir-based triple therapy in hepatitis C virus (HCV)-G1 menopausal women who were historic relapsers, partial-responders and null-responders. In this single-assignment, unblinded study, we treated fifty-six menopausal women with HCV-G1, 46% F3-F4, and previous PEG-α/RBV failure (7% null, 41% non-responder, and 52% relapser) with 4 wk lead-in with PEG-IFNα2b/RBV followed by PEG-IFNα2b/RBV+Boceprevir for 32 wk, with an additional 12 wk of PEG-IFN-α-2b/RBV if patients were HCV-RNA-positive by week 8. In previous null-responders, 44 wk of triple therapy was used. The primary objective of retreatment was to verify whether a sustained virological response (SVR) (HCV RNA undetectable at 24 wk of follow-up) rate of at least 20% could be obtained. The secondary objective was the evaluation of the percent of patients with negative HCV RNA at week 4 (RVR), 8 (RVR BOC), 12 (EVR), or at the end-of-treatment (ETR) that reached SVR. To assess the relationship between SVR and clinical and biochemical parameters, multiple logistic regression analysis was used. After lead-in, only two patients had RVR; HCV-RNA was unchanged in all but 62% who had ≤ 1 log10 decrease. After Boceprevir, HCV RNA became undetectable at week 8 in 32/56 (57.1%) and at week 12 in 41/56 (73.2%). Of these, 53.8% and 52.0%, respectively, achieved SVR. Overall, SVR was obtained in 25/56 (44.6%). SVR was achieved in 55% previous relapsers vs. 41% non-responders (P = 0.250), in 44% F0-F2 vs 54% F3-F4 (P = 0.488), and in 11/19 (57.9%) of patients with cirrhosis. At univariate analysis for baseline predictors of SVR, only previous response to antiviral therapy (OR = 2.662, 95%CI: 0.957-6.881, P = 0.043), was related with SVR. When considering "on treatment" factors, 1 log10 HCV RNA decline at week 4 (3.733, 95%CI: 1.676-12.658, P = 0.034) and achievement of RVR BOC (7.347, 95%CI: 2.156-25.035, P = 0.001) were significantly related with the SVR, although RVR BOC only (6.794, 95%CI: 1.596-21.644, P = 0.010) maintained significance at multivariate logistic regression analysis. Anemia and neutropenia were managed with Erythropoietin and Filgrastim supplementation, respectively. Only six patients discontinued therapy. Boceprevir obtained high SVR response independent of previous response, RVR or baseline fibrosis or cirrhosis. RVR BOC was the only independent predictor of SVR.

IL28B polymorphism genotyping as predictor of rapid virologic response during interferon plus ribavirin treatment in hepatitis C virus genotype 1 patients.

To clarify the association of interleukin-28B (IL28B) single nucleotide polymorphisms (SNPs) with hepatitis C virus (HCV) viremia changes for assessment of interferon (IFN) response. A cohort of 118 Caucasian treatment-naïve HCV-G1 infected patients, treated with pegylated-IFN alpha 2a or 2b associated with ribavirin (53 responders, 65 non-responders) during the period 2010-2012, were genotyped for IL28B SNPs rs12979860 C>T and rs8099917 T>G. Genotyping was performed by real-time allelic discrimination assay. Serum HCV RNA levels were assayed at 2, 4, 12, 24 and 48 wk during therapy. Correlation between IL28B genotypes and serum HCV RNA kinetics was investigated. Multivariable logistic regression analysis was performed to identify predictors of null-response. Twenty-six out of 118 patients (22%) had no HCV RNA decline ≥ 1 log IU/mL at therapy week 4 (null-responders). IL28B genotype was rs8099917 (G)/rs1297860 in 21/26 (80%) of null-responder patients. Using multivariate analysis, it was shown that the presence of the rs8099917 G allele was the best predictor of null-response (OR = 7.9, 95%CI: 1.99-31.18). The presence of at least one favorable genotype showed a positive predictive value of above 90% for HCV RNA reduction ≥ log at week 4. Analysis of the HCV RNA kinetics during 12 wk of therapy in patients with IL28B rs12979860 CT heterozygosis (n = 73), according to their rs8099917 status, showed that the viremia reduction was significantly different in patients carrying the rs8099917 G allele compared to those with favorable homozygosis. Our findings emphasize the association of the IL28B rs8099917 G allele with HCV. Genotyping for both IL28B SNPs is useful in clinical practice for thorough patient risk stratification based on IFN responsiveness.

Boceprevir for chronic HCV genotype 1 infection in patients with prior treatment failure to peginterferon/ribavirin, including prior null response

Boceprevir with peginterferon/ribavirin (BOC/PR) leads to significantly higher sustained virological response (SVR) rates in patients with chronic hepatitis C and partial response or relapse after prior treatment with peginterferon/ribavirin. We studied the efficacy of BOC/PR in patients with prior treatment failure, including those with a null response (<2-log10 decline in HCV RNA), to peginterferon/ribavirin. Patients in the control arms of boceprevir Phase 2/3 studies who did not achieve SVR were re-treated with BOC/PR for up to 44 weeks. Patients enrolling >2 weeks after end-of-treatment in the prior study received PR for 4 weeks before adding boceprevir. Of 168 patients enrolled, four discontinued from the PR lead-in and 164 received BOC/PR. Baseline viral load was >800,000 IU/ml in 77% of patients; 62% had HCV genotype 1a, and 10% were cirrhotic. In the ITT analysis (all 168 patients), SVR was achieved in 20 (38%) of 52 patients with prior null response, 57 (67%) of 85 with prior partial response, and 27 (93%) of 29 with prior relapse. In the mITT analysis (164 BOC/PR-treated patients), SVR rates were 41% (20/49), 67% (57/85), and 96% (27/28), respectively. SVR was achieved by 48% of patients with <1-log10 decline in HCV-RNA after lead-in and 76% of those with ⩾ 1-log10 decline or undetectable HCV-RNA after lead-in. The most common adverse events were anemia (49%), fatigue (48%), and dysgeusia (35%); 8% of patients discontinued due to adverse events. Re-treatment with BOC/PR improved SVR rates in all patient subgroups, including those with prior null response.

Pretreatment Predictive Factors for Hepatitis C Therapy Outcome: Relevance of Anti-E1E2 Antibodies Compared to Ip-10 and Il28B Genotypes

Unique serum anti-E1E2 antibodies were shown to be associated with spontaneous recovery or predictive of sustained virological response (SVR) in patients with chronic hepatitis C receiving pegylated interferon/ribavirin (PEG-IFN/RBV) therapy. The objectives were to establish the relationship between pretreatment anti-E1E2 titres and HCV RNA kinetics during PEG-IFN/RBV therapy, and to examine whether the combined determination of interleukin (IL)28B rs12979860 and rs8099917, pretreatment inducible protein (IP)-10 levels and/or anti-E1E2 improved the prediction of SVR. Sera from 26 treatment-naive consecutive HCV patients treated with PEG-IFN/RBV for 48 weeks were analysed. Serum anti-E1E2 titres and pretreatment IP-10 levels were measured by enzyme-linked immunosorbent assays. The IL28B variants were determined using genotyping real-time polymerase chain reaction method. Viral decline was measured at weeks (W) 4 and 12 and SVR assessed 6 months after the end of therapy. Baseline anti-E1E2 titres were correlated with HCV RNA decline at W4 and W12 and were highly predictive of SVR with 100% of patients negative for anti-E1E2 failing to achieve SVR. Receiver operating characteristic curve analyses indicate that the best prediction of SVR (AUC 0.990) was obtained with the combination of anti-E1E2 and IP-10 levels. Predictive values were better than those obtained with IP-10 alone or in combination with IL28B variants. Pretreatment serum anti-E1E2 response predicts HCV RNA clearance kinetics and treatment outcome. The combination of anti-E1E2 and IP-10 significantly improved the prediction of treatment response. This warrants further investigation and validation on larger cohorts of patients in the context of new therapeutic strategies.

Therapeutic efficacy of potent neutralizing HIV-1-specific monoclonal antibodies in SHIV-infected rhesus monkeys

HIV-1-specific monoclonal antibodies (mAbs) with extraordinary potency and breadth have recently been described. In humanized mice, combinations of mAbs have been shown to suppress viremia, but the therapeutic potential of these mAbs has not yet been evaluated in primates with an intact immune system. Here we show that administration of a cocktail of HIV-1-specific mAbs, as well as the single glycan-dependent mAb PGT121, resulted in a rapid and precipitous decline of plasma viremia to undetectable levels in rhesus monkeys chronically infected with the pathogenic virus SHIV-SF162P3. A single mAb infusion afforded up to a 3.1 log decline of plasma viral RNA in 7 days and also reduced proviral DNA in peripheral blood, gastrointestinal mucosa, and lymph nodes without the development of viral resistance. Moreover, following mAb administration, host Gag-specific T lymphocyte responses exhibited improved functionality. Virus rebounded in the majority of animals after a median of 56 days when serum mAb titers had declined to undetectable levels, although a subset of animals maintained long-term virologic control in the absence of further mAb infusions. These data demonstrate a profound therapeutic effect of potent neutralizing HIV-1-specific mAbs in SHIV-infected rhesus monkeys as well as an impact on host immune responses. Our findings strongly encourage the investigation of mAb therapy for HIV-1 in humans.

Randomized trial of daclatasvir and asunaprevir with or without PegIFN/RBV for hepatitis C virus genotype 1 null responders

Patients with chronic hepatitis C virus (HCV) infection and prior null response (<2 log HCV RNA decline after ⩾ 12 weeks of PegIFN/RBV) have limited options. We evaluated daclatasvir plus once- or twice-daily asunaprevir in non-cirrhotic genotype 1 null responders. In this randomized, phase 2a, open-label, 24-week treatment study, 101 patients received daclatasvir (60 mg) once-daily. In addition, 38 genotype 1b patients received asunaprevir (200mg) twice- (DUAL A1) or once-daily (DUAL A2); 36 genotype 1a and 5 genotype 1b patients received asunaprevir twice- (QUAD B1) or once-daily (QUAD B2) plus PegIFN/RBV; and 18 genotype 1a and 4 genotype 1b patients received asunaprevir twice-daily plus ribavirin (TRIPLE B3). The primary endpoint was undetectable HCV RNA 12 weeks post-treatment (sustained virologic response, SVR12). Across all groups, mean HCV RNA was ⩾ 6 log IU/ml, and 99% of patients had a non-CC IL28B genotype. SVR12 rates were 78% (A1), 65% (A2), 95% (B1), and 95% (B2). In B3, most genotype 1a patients experienced virologic breakthrough. The most common adverse events were headache, diarrhea, and asthenia. Grade 3-4 aminotransferase elevations were infrequent and not treatment-limiting. In genotype 1 null responders, daclatasvir plus twice-daily asunaprevir DUAL therapy is effective for most genotype 1b patients, and daclatasvir, asunaprevir, and PegIFN/RBV QUAD therapy is effective for nearly all genotype 1a and 1b patients; but neither DUAL nor TRIPLE therapy is effective for genotype 1a patients. Interferon-free regimens including daclatasvir and twice-daily asunaprevir for genotype 1 null responders should be tailored to subtype.