Efficacy of 12 or 18 weeks of elbasvir plus grazoprevir with ribavirin in treatment‐naïve,noncirrhotic HCV genotype 3‐infected patients

Elbasvir (EBR; HCV NS5A inhibitor) and grazoprevir (GZR; HCV NS3/4A protease inhibitor) are approved as a fixed‐dose combination to treat patients chronically infected with HCV genotypes 1 and 4. During the development programme and supported by in vitro potency, the efficacy of EBR+GZR was assessed in HCV GT3‐infected patients. This study's aim was to determine the efficacy and tolerability of 12 or 18 weeks of EBR+GZR with ribavirin (RBV) in treatment‐naïve, noncirrhotic HCV GT3‐infected patients. Randomized patients received open‐label EBR (50 mg once daily) + GZR (100 mg once daily) + RBV. The primary efficacy objective was to evaluate the sustained virologic response rates 12 weeks after the end of all study therapy (SVR12). SVR12 rates (95% confidence interval) were 45.0% (23.1, 68.5) and 57.1% (34.0, 78.2) after treatment with EBR+GZR+RBV for 12 weeks or 18 weeks, respectively. On‐treatment virologic failure was observed in 41% (17 of 41) of patients. At virologic failure, resistance‐associated substitutions (RASs) with a >five‐fold shift in potency occurred in the NS3 region in six (35%) patients and in the NS5A region in 16 (94%) patients. The most common RAS at virologic failure was Y93H in NS5A which was identified in 13 of 17 (76%) patients. The efficacy of EBR+GZR+RBV was suboptimal in HCV GT3‐infected patients due to a high rate of on‐treatment virologic failure and treatment‐emergent RASs which demonstrates an inadequate barrier to the development of GT3 resistance. However, rapid viral clearance demonstrated the antiviral activity of EBR+GZR+RBV in GT3‐infected patients.clinicaltrials.gov: NCT01717326.     

Efficacy and safety of 12 weeks of elbasvir ± grazoprevir ± ribavirin in participants with hepatitis C virus genotype 2, 4, 5 or 6 infection: The C‐SCAPE study

People with hepatitis C virus (HCV) infection other than genotype 1 represent a heterogeneous group. The aim of the phase 2 C‐SCAPE study was to evaluate elbasvir/grazoprevir (EBR/GZR), with or without ribavirin (RBV), in participants with HCV genotype 2, 4, 5 or 6 infection. This was a part randomised, open‐label, parallel‐group study (NCT01932762; PN047‐03) of treatment‐naive, noncirrhotic participants. Participants with HCV genotype 2 infection received GZR 100 mg + RBV ± EBR 50 mg for 12 weeks and those with genotype 4, 5 or 6 infection were randomized to receive EBR/GZR ± RBV for 12 weeks. The primary endpoint was sustained virological response 12 weeks after completion of treatment (SVR12; HCV RNA <25 IU/mL). Among participants with genotype 2 infection, SVR12 was achieved by 80% (24/30) of those receiving EBR/GZR + RBV and 73% (19/26) of those receiving GZR + RBV. SVR rates were high in participants with HCV genotype 4 infection receiving EBR/GZR with and without RBV (100% [10/10] and 90% [9/10]; respectively). In contrast, the addition of RBV to EBR/GZR appeared to increase SVR12 in participants with genotype 5 infection (EBR/GZR, 25%; EBR/GZR + RBV 100% [4/4]). In participants with genotype 6 infection, SVR12 was 75% (3/4) in both those receiving EBR/GZR and those receiving EBR/GZR + RBV. The safety profile was similar across treatment arms, with adverse events tending to occur more frequently among participants receiving RBV. In conclusion, these data support the inclusion of participants with genotype 4 or 6 infection in the EBR/GZR phase 3 studies. EBR/GZR ± RBV was unsatisfactory for participants with genotype 2 or 5 infection.     

Implications of HCV RNA level at week 4 of direct antiviral treatments for hepatitis C

We aimed to determine whether the HCV viral load after four weeks of treatment (W4VL) with direct‐acting antiviral agents (DAAs) predicts sustained virologic response (SVR) in a real‐world clinical setting. We identified 21 095 patients who initiated DAA‐based antiviral treatment in the national Veterans Affairs (VA) healthcare system from 01/01/2014 to 06/30/2015. Week 4 viral load was categorized as undetectable, detectable below quantification (DBQ), detectable above quantification (DAQ) with viral load ≤42 IU/mL and DAQ with viral load >42 IU/mL. Week 4 viral load was undetectable in 36.1%, detectable below quantification in 45.6%, DAQ ≤42 in 9.3%, DAQ >42 in 9.1%. Detectable above quantification was much more common and undetectable week 4 viral load much less common when tested with the Abbott RealTime HCV assay vs the Roche COBAS AmpliPrep/COBAS TaqMan Version 2 assay. Compared to patients with undetectable week 4 viral load (SVR=93.5%), those with detectable below quantification (SVR=91.8%, adjusted odds ratio [AOR] 0.79, P‐value=.001), DAQ ≤42 (SVR=90.0%, AOR 0.63, P‐value<.001) and DAQ >42 (SVR=86.2%, AOR 0.52, P‐value<.001) had progressively lower likelihood of achieving SVR after adjusting for baseline characteristics and treatment duration. Among genotype 1‐infected patients who were potentially eligible for 8‐week sofosbuvir/ledipasvir monotherapy, we did not find evidence that treatment for 12 weeks instead of 8 weeks was associated with higher SVR, even among those with detectable above quantification. In summary, DBQ and DAQ W4VL are very common in real‐world practice, contrary to what was reported in clinical trials, and strongly predict reduced SVR across genotypes and clinically relevant patient subgroups. Whether and how week 4 viral load results should influence treatment decisions requires further study.     

The safety and efficacy of elbasvir and grazoprevir in participants with hepatitis C virus genotype 1b infection

Background

Genotype 1b (GT1b) is the most common subtype of the hepatitis C virus (HCV). We present an integrated analysis of 1070 participants with HCV GT1b infection from 30 countries who received elbasvir/grazoprevir for 12 weeks.

Methods

This is a retrospective analysis of data from participants with chronic HCV GT1b infection enrolled in 11 phase II/III clinical trials. All participants received elbasvir 50 mg plus grazoprevir 100 mg once daily for 12 weeks. The primary end point of all studies was sustained virologic response 12 weeks after completion of therapy (SVR12, HCV RNA < 15 IU/ml).

Results

SVR12 was 97.2% (1040/1070). Of the 30 participants who failed to attain SVR12, 15 relapsed and 15 had nonvirologic failure. Among participant subgroups, SVR12 was high in those with compensated cirrhosis (188/189, 99.5%), HIV co-infection (51/54, 94.4%), and baseline viral load > 800,000 IU/ml (705/728, 96.8%). Resistance-associated substitutions (RASs) at NS5A positions 28, 30, 31, or 93 were present in 21.6% of participants at baseline. SVR12 was 99.6% (820/823) in participants without baseline NS5A RASs and 94.7% (215/227) in those with baseline NS5A RASs. Serious adverse events occurred in 3.2% (34/1070) of participants, nine of which occurred after study medication was completed.

Conclusions

Elbasvir/grazoprevir for 12 weeks represents an effective treatment option for participants with HCV GT1b infection. SVR12 was high in all participant subgroups, including those with compensated cirrhosis, HIV co-infection, and high baseline viral load.

ClinicalTrials.gov identifiers

The trials discussed in this paper were registered with Clinicaltrial.gov as the following: NCT02092350 (C-SURFER), NCT02105662 (C-EDGE Co-Infection), NCT02105467 (C-EDGE treatment-naive), NCT02105701 (C-EDGE treatment-experienced), NCT01717326 (C-WORTHy), NCT02251990 (C-CORAL), NCT02105688 (C-EDGE COSTAR), NCT02252016 (C-EDGE IBLD), NCT02115321 (C-SALT), NCT02203149 (Japan phase 2/3 study), NCT02358044 (C-EDGE Head-2-Head).

     

Peginterferon-alpha-2a (40KD) and ribavirin for 16 or 24 weeks in patients with genotype 2 or 3 chronic hepatitis C

BACKGROUND & AIMS: Standard therapy of patients with chronic hepatitis C virus (HCV) infected with HCV genotype-2 or -3 is the combination of pegylated interferon-alpha and ribavirin for 24 weeks. Whether shorter treatment durations are possible for these patients without compromising sustained virologic response rates is unknown. METHODS: Patients chronically infected with HCV-2 (n = 39), HCV-2/3 (n = 1), or HCV-3 (n = 113) were treated with peginterferon-alpha-2a (180 microg/wk) plus ribavirin 800-1200 mg/day. HCV RNA was quantitatively assessed after 4 weeks. Patients with a rapid virologic response (HCV RNA below 600 IU/mL) were randomized for a total treatment duration of 16 (group A) or 24 weeks (group B). All patients with HCV RNA > or =600 IU/mL at week 4 (group C) were treated for 24 weeks. End-of-treatment and sustained virologic response were assessed by qualitative RT-PCR (sensitivity 50 IU/mL). RESULTS: Only 11 of 153 patients (7%) were allocated to group C. End-of-treatment and sustained virologic response rates were 94% and 82%, (group A), 85% and 80% (group B), and 73% and 36% (group C), respectively. In patients infected with genotype HCV-3 and high viral load (>800,000 IU/mL), a significant lower sustained virologic response rate was found than in patients infected with HCV-3 and a viral load lower or equal to 800,000 IU/mL (59% vs 85%, respectively; P = .003). CONCLUSIONS: In HCV-2 and -3 (low viral load)-infected patients who have a rapid virologic response, treatment for 16 weeks with peginterferon-alpha-2a and ribavirin is sufficient. In patients infected by HCV-3 (high viral load), longer treatment may be necessary.     

Cost‐effectiveness of elbasvir/grazoprevir use in treatment‐naive and treatment‐experienced patients with hepatitis C virus genotype 1 infection and chronic kidney disease in the United States

Among patients with chronic kidney disease (CKD) in the United States, HCV infection causes significant morbidity and mortality and results in substantial healthcare costs. A once‐daily oral regimen of elbasvir/grazoprevir (EBR/GZR) for 12 weeks was found to be a safe and efficacious treatment for HCV in patients with CKD. We evaluated the cost‐effectiveness of EBR/GZR in treatment‐naïve and treatment‐experienced CKD patients compared with no treatment (NoTx) and pegylated interferon plus ribavirin (peg‐IFN/RBV) using a computer‐based model of the natural history of chronic HCV genotype 1 infection, CKD and liver disease. Data on baseline characteristics of the simulated patients were obtained from NHANES, 2000–2010. Model inputs were estimated from published studies. Cost of treatment with EBR/GZR and peg‐INF/RBV were based on wholesale acquisition cost. All costs were from a third‐party payer perspective and were expressed in 2015 U.S. dollars. We estimated lifetime incidence of liver‐related complications, liver transplantation, kidney transplantation, end‐stage live disease mortality and end‐stage renal disease mortality; lifetime quality‐adjusted life years (QALY); and incremental cost‐utility ratios (ICUR). The model predicted that EBR/GZR will significantly reduce the incidence of liver‐related complications and prolong life in patients with chronic HCV genotype 1 infection and CKD compared with NoTx or use of peg‐IFN/RBV. EBR/GZR‐based regimens resulted in higher average remaining QALYs and higher costs (11.5716, $191 242) compared with NoTx (8.9199, $156 236) or peg‐INF/RBV (10.2857, $186 701). Peg‐IFN/RBV is not cost‐effective, and the ICUR of EBR/GZR compared with NoTx was $13 200/QALY. Treatment of a patient on haemodialysis with EBR/GZR resulted in a higher ICUR ($217 000/QALY). Assuming a threshold of $100 000 per QALY gained for cost‐effectiveness, use of elbasvir/grazoprevir to treat an average patient with CKD can be considered cost‐effective in the United States.     

Efficacy of 8 weeks elbasvir/grazoprevir regimen for naïve-genotype 1b,HCV infected patients with or without glucose abnormalities: Results of the EGG18 study

Background and aimDirect Acting Antivirals(DAAs) achieve the highest rate of sustained viral response(SVR) in patients with genotype-1b(G1b) Hepatitis C virus(HCV) infection. Reducing treatment duration can simplify the management and improve adherence of therapy.Patients and methodsThe study evaluates the efficacy of 8 weeks of elbasvir/grazoprevir regimen in 75 treatment-naïve(TN), G1b patients with mild-moderate fibrosis(Liver Stiffness by Fibroscan® <9.0 kPa). Viral load(VL) has been evaluated by Roche TaqMan RT-PCR(LLOQ<15 IU/ml).ResultsMean age was 61.0 ± 14.2 years, 44% were male, mean LS by Fibroscan® was 6.1 ± 1.8 kPa. Twenty-eight patients(37.3%) had an HOMA>2.5. Two patients were excluded from analysis(one dropped out and the other one had diagnosed genotype 2c at genotyping by sequencing performed after relapse).At 8 weeks(EOT), 71 out of 73 patients(97.3%) had undetectable HCV-RNA, while in two cases HCV-RNA was detectable but with VL<15 IU/ml. Both of them achieved SVR. Two G1b patients relapsed at 12 weeks of follow-up, both with baseline VL>800,000 IU/ml and HOMA score 1.3 and 3.8 respectively. Both had undetectable HCV VL at 4th week and at the EOT. Modified intention-to-treat SVR12 for G1b patients was 71/73(97.3%).ConclusionIn naïve, genotype-1b HCV-infected patients with mild/moderate liver fibrosis, short course of 8 weeks of EBR/GZR appears to achieve high efficacy regardless of features of insulin resistance.     

Quasispecies as Predictive Response Factors for Antiviral Treatment in Patients with Chronic Hepatitis C

The object of this study was to evaluate the viral factor, especially the quasispecies, as predictive of sustained virologic response. We studied the quasispecies, genotype, viral load, and hepatitis C (HCV) cAg in 41 patients with chronic hepatitis C treated with interferon and in 84 with interferon and ribavirin. In the interferon group, responders presented a lower viral load. From logistic regression analysis of patients treated with interferon plus ribavirin, independent predictors for sustained virologic response were genotype 3a, a low baseline viral load and ≤3 bands quasispecies. Genotype and viral load presented higher specificity and positive predictive value than did quasispecies. In patients with genotype 1, viral load ≤5 × 10⁵ IU/mL and ≤3 quasispecies were predictive for sustained virologic response. In conclusion, the predictive factors of virologic response are genotype, viral load, and quasispecies. Quasispecies did not improve on the genotype or the viral load as predictors of virologic response.     

Clinical utility of viral load measurements in individuals with chronic hepatitis C infection on antiviral therapy

SUMMARY: Both absolute viral load and log decline in viral load from baseline were found clinically useful in predicting sustained virological response and lack of sustained virological response (non-sustained virological response, NSVR) to treatment. We assessed the clinical utility of hepatitis C virus (HCV) RNA quantitation and changes in viral load using the VERSANT HCV RNA 3.0 Assay (bDNA) in 351 HCV-infected individuals treated with interferon plus ribavirin. We show that viral load decision thresholds provided negative predictive values (NPVs) of >95% at week 4 using a 100 000 IU/mL cut-off and at weeks 8 and 12 using 10 000 IU/mL cut-offs. A 2-log decline from baseline provided NPVs >95% at weeks 8 and 12. Combinations of absolute viral loads and changes in viral load from baseline did not enhance the performance of the decision rules for predicting NSVR. The positive predictive values (PPVs) at weeks 8 and 12 were 59.1 and 67.3%. This study highlights the critical importance of viral quantitation in gauging therapeutic response in patients with chronic HCV infection on antiviral therapy. Early changes in viral load, measured as absolute viral loads or change in viral load from baseline, are highly predictive of NSVR at 8 and 12 weeks. PPVs are modest but these data may provide encouragement to patients who are in the early phases of treatment when side effects are frequent. Additionally, we demonstrated the need for cautious interpretation of stopping rules when the values are at or near the decision thresholds.     

Effectiveness and safety of elbasvir/grazoprevir therapy in patients with chronic HCV infection: Results from the Spanish HEPA‐C real‐world cohort

In randomized controlled trials of patients with chronic HCV infection, elbasvir/grazoprevir (EBR/GZR) demonstrated high cure rates and a good safety profile. This study assessed the effectiveness and safety of EBR/GZR, with and without ribavirin, in a real‐world HCV patient cohort. HEPA‐C is a collaborative, monitored national registry of HCV patients directed by the Spanish Association for the Study of the Liver and the Networked Biomedical Research Centre for Hepatic and Digestive Diseases. Patients entered into HEPA‐C between December 2016 and May 2017, and treated with EBR/GZR with at least end‐of‐treatment response data, were included. Demographic, clinical and virologic data were analysed, and adverse events (AEs) recorded. A total of 804 patients were included in the study. The majority were male (57.9%), with a mean age of 60 (range, 19‐92) years. Genotype (GT) distribution was GT 1, 86.8% (1a, 14.3%; 1b, 72.5%); GT 4, 13.2% and 176 patients (21.9%) were cirrhotic. Overall, among 588 patients with available data, 570 (96.9%) achieved sustained virologic response at 12 weeks post‐treatment (SVR12). SVR12 rates by genotype were GT 1a, 97.7%; GT 1b, 98.6%; and GT 4, 98.1%. No significant differences in SVR12 according to fibrosis stage were observed. Eighty patients experienced an AE, resulting in treatment discontinuation in three. In this large cohort of patients with chronic HCV managed in a real‐world setting in Spain, EBR/GZR achieved high rates of SVR12, comparable to those observed in randomized controlled trials, with a similarly good safety profile.     

Tenofovir versus tenofovir plus entecavir for chronic hepatitis B with lamivudine resistance and entecavir resistance

We compared the viral suppressive efficacy of tenofovir disoproxil fumarate (TDF) mono‐rescue therapy (TDF group) and TDF plus entecavir (ETV) combination‐rescue therapy (TDF + ETV group) in chronic hepatitis B (CHB) patients with lamivudine resistance and entecavir resistance. One hundred and thirty‐three CHB patients with lamivudine and entecavir resistance were investigated. Ninety‐six patients were treated with TDF and 37 with TDF + ETV for at least 6 months. We compared the virologic response rate (HBV DNA level <20 IU/mL) between the two groups and identified the predictive factors of treatment outcome. There were no significant differences between the two groups in demographic characteristics. Up to 24 months [median: 18 (range 6‐24) months], 85.4% and 89.2% of the TDF group and TDF + ETV group, respectively, achieved a virologic response (P=.068). Only the HBV DNA level at baseline was significantly associated with a virologic response in the multivariate analysis. In a subanalysis of patients with HBV DNA levels ≥4 log (IU/mL) at baseline, a higher proportion of patients in the TDF + ETV group than the TDF group achieved a virologic response (92.9% vs 68.3%; P<.001), while 90% of patients with HBV DNA (IU/mL) levels <4 log in all both TDF and TDF + ETV groups achieved a virologic response. TDF mono‐rescue therapy is a reasonable option in patients with lamivudine resistance and entecavir resistance. However, the combination strategy should be considered in patients with high baseline HBV DNA levels.     

Increased eligibility for treatment of chronic hepatitis C infection with shortened duration of therapy: Implications for access to care and elimination strategies in Canada

BACKGROUND:

All oral, highly effective direct-acting antiviral combinations, such as sofosbuvir-ledipasvir, have recently been licensed in Canada but cost as much as $67,000 for a 12-week course of therapy, representing a major economic barrier to predominately single-payer health care systems such as that found in Ontario. In hepatitis C virus (HCV) genotype 1 noncirrhotic patients with a baseline viral load of <6×10⁶ IU/mL, treatment with sofosbuvir-ledipasvir can be shortened to eight weeks without compromising ≥95% efficacy. The number of HCV-infected patients in Ontario eligible for shortened therapy, and the associated cost savings, are unknown. The authors propose that treating every patient with shortened therapy, regardless of baseline viral load, would lead to significant public cost savings and collateral efficiencies, enabling increased HCV treatment capacity and cure.

METHODS:

The present study designed a three-part model to investigate the cost of cure per patient and cost savings per patient under three eligibility pathways: conservative, permissive and ideal. In the conservative model, every patient is treated for 12 weeks regardless of baseline viral load, whereas in the permissive model, patients with a baseline viral load <6×10⁶ IU/mL are treated for eight weeks. In the ideal model, every patient receives eight weeks of therapy regardless of baseline viral load. Relapsed patients are retreated for 12 weeks. Data obtained from the Ontario Public Health Laboratory were used to validate the model and generate the outcomes.

RESULTS:

In Ontario, 75.34% of HCV genotype 1 patients had a baseline viral load of <6×10⁶ IU/mL and were eligible for shortened therapy. The cost of cure per patient in the ideal model was $47,328.44, representing a 29% reduction in the cost of curative therapy and 3.5 weeks of shortened treatment duration compared with the conservative model. The ideal model generated a cost savings per patient of $3,855.17 (8% reduction in treatment cost) and 0.7 weeks of shorter therapy compared with the permissive model, and was the shortest and most efficient while maintaining a cure rate ≥95%.

CONCLUSIONS:

These results demonstrate that recommendations for a shortened treatment course of eight weeks using all-oral direct-acting antivirals in HCV genotype 1 noncirrhotic patients, regardless of baseline viral load, affords significant public cost savings and, on a population level, offers opportunities for expanded HCV treatment and cure.     

Efficacy and safety of grazoprevir + ribavirin for 12 or 24 weeks in treatment‐naïve patients with hepatitis C virus genotype 1 infection

Grazoprevir (GZR) is a second‐generation hepatitis C virus NS3/4A protease inhibitor. The aim of this study was to evaluate GZR plus ribavirin (RBV) in patients with HCV GT1 infection. Noncirrhotic, IL28B CC patients with HCV genotype 1 infection were randomized to GZR 100 mg once daily and RBV for 12 or 24 weeks. Patients in the 12‐week arm with detectable HCV RNA at treatment week 4 (TW4) had treatment extended to 24 weeks (response‐guided therapy, RGT). The primary endpoint was sustained virologic response (SVR12) at follow‐up week 12 (HCV RNA <25 IU/mL) in the per‐protocol (PP) population (excluding patients with important protocol deviations). Twenty‐six patients were randomized and 22 were included in the PP population. SVR12 was 58.3% (7 of 12) and 90% (9 of 10) in the RGT and 24‐week arms, respectively. Seven PP patients had virologic failure, including one patient in the 24‐week arm who relapsed after follow‐up week 12. All three breakthrough patients had wild‐type (WT) virus at baseline and developed breakthrough at TW6 or TW12 with Y56H, A156T and D168A/N mutations. Of the five relapse patients, four had WT at baseline (at relapse three had WT and one had V55A and D168A), and one had S122A/T at baseline and S122T at relapse. There were no serious adverse events (AEs), discontinuations due to AEs or grade 3/4 elevations in total and/or direct bilirubin. Grazoprevir plus RBV was associated with a rapid and sustained suppression of HCV RNA. These results support further evaluation of grazoprevir‐based regimens (NCT01716156; protocol P039).     

Viral load and clinical manifestations of hepatitis E virus genotype 3 infections

A fraction of plasma donations undergoes hepatitis E virus (HEV) RNA screening since late 2014 in France. The aim of this study was to determine the frequency of HEV RNA as well as the viral load and the evolution of genotype distribution over a 3‐year period (2015‐2017) in asymptomatic blood donors in comparison with symptomatic patients routinely diagnosed. The overall detection rate of HEV RNA in plasma donations was 0.10% during the 3‐year period, with a median viral load of 717 IU/mL (range: <60‐168 000 IU/mL) in the 189 samples found HEV RNA positive. One hundred and twenty samples (64.4%) were successfully HEV genotyped. Most strains were HEV3f (n = 54; 44.3%) and HEV3c (n = 46; 37.7%). The genotype distribution was not different throughout the 3‐year period and we found no association between the genotype and where the blood donors lived (P = 0.96). The HEV genotype distributions in infected blood donors and symptomatic patients were similar. However, the symptomatic patients had a higher viral load (median 282 000 IU/mL; range: <60‐136 000 000 IU/mL; P < 0.01) than the blood donors. Overall, asymptomatic blood donors and patients with symptomatic hepatitis E had similar genotype distributions but the blood donors had lower viral loads.     

Prediction of virologic response in difficult-to-treat chronic hepatitis C patients during high-dose interferon induction therapy

Objective. To determine (i) whether early viral kinetics or other markers during a modified treatment regimen are predictors of treatment outcome and (ii) whether fast responders can be treated for 24 weeks, without compromising the sustained virologic response (SVR) rate. Material and methods. One hundred “difficult-to-treat” chronic hepatitis C patients (46 previous non-responders/relapsers (any genotype), 54 treatment-naive patients genotypes 1 and 4) were treated with triple antiviral induction therapy: amantadine hydrochloride and ribavirin, combined with 6 weeks interferon alfa-2b induction (weeks 1–2: 18 MU/day, weeks 3–4: 9 MU/day, weeks 5–6: 6 MU/day), thereafter combined with weekly peginterferon alfa-2b. Fast responders (≥3 log₁₀ HCV RNA decline at week 4) were randomized to 24 or 48 weeks. Slow responders (<3 log₁₀ HCV RNA decline at week 4) were treated for 48 weeks. Treatment was stopped in patients with detectable HCV RNA at week 24. Results. Thirty-six patients achieved SVR: 28 of 60 fast responders (47%) versus 8 of 32 slow responders (25%, p<0.05). Relapse rates among fast responders treated for 24 or 48 weeks were 27% and 20%, respectively (p=NS). SVR in fast responders was independent of baseline HCV RNA ≥ or <600,000 IU/mL. All treatment-naive patients with HCV RNA <5 IU/mL at week 1 or 2 achieved SVR; all treatment-naive patients with HCV RNA ≥5 IU/mL at week 16 became non-SVR. In previous non-responders/relapsers, the predictive value for SVR was 83% if HCV RNA was <5 IU/mL at week 2; all previous non-responders/relapsers with HCV RNA ≥5 IU/mL at week 8 became non-SVR. Conclusions. With high-dose interferon induction, SVR and non-SVR can be predicted reliably within 16 weeks. Fast responders can be treated for 24 weeks, and SVR is independent of baseline viral load in fast responders.     

Nonstructural protein 5A resistance profile in patients with chronic hepatitis C treated with ledipasvir‐containing regimens without sofosbuvir

The study aimed to evaluate the effects of baseline hepatitis C virus (HCV) nonstructural protein 5A (NS5A) resistance‐associated substitutions (RASs) on sustained virologic response to ledipasvir (LDV)‐containing regimens in the absence of sofosbuvir (SOF) in patients with HCV genotype (GT) 1 infection across 6 phase 2 clinical studies. We analysed data from 1103 patients who received either LDV + vedroprevir (NS3 protease inhibitor) + tegobuvir (NS5B inhibitor) ± ribavirin or LDV + ribavirin + pegylated interferon. Population sequencing of HCV NS5A was performed at baseline and at virologic failure from patient plasma samples. Of 1045 patients with available baseline sequences, 747 (67.7%) had GT1a, and 298 (26.9%) had GT1b infection. The overall prevalence of NS5A RASs at baseline was 9.4%; 7.6% (57/747) and 13.8% (41/298) of patients with GT1a and GT1b infection, respectively. The majority of GT1a‐infected patients with NS5A RASs at baseline had a single NS5A RAS (78.9%) at NS5A positions K24R, M28T, Q30H/L, L31M and Y93H/N/C/S. The spectrum of NS5A RASs detected in GT1b patients was much less diverse compared to GT1a patients, with all patients harbouring a single NS5A RAS either L31M or Y93H/C. For patients treated with LDV‐containing regimens in the absence of SOF, the presence of baseline NS5A RASs was associated with low SVR rates. In patients with virologic failure, nearly all had either pre‐existing and/or emergent NS5A RASs: 287/287 (100%) and 40/42 (95.2%) patients with GT1a and GT1b infection, respectively. Three novel NS5A substitutions were identified as emergent NS5A RASs: K26E and S38F in GT1a; and L31I in GT1b. In conclusion, the presence of NS5A RASs at baseline reduced the SVR rate in patients treated with LDV in combination vedroprevir + tegobuvir ± ribavirin or ribavirin + pegylated interferon. Virologic failure was associated with the detection of NS5A RASs in nearly all patients. These results suggest that the resistance barrier may differ depending on HCV drug combination and may be more important than that of the individual DAAs.     

Optimized threshold for serum HCV RNA to predict treatment outcomes in hepatitis C patients receiving peginterferon alfa‐2a/ribavirin

Summary. It is unclear whether the current threshold for ‘high’ hepatitis C virus (HCV) RNA level (800 000 IU/mL) is optimal for predicting sustained virological response (SVR). We retrospectively analysed pretreatment HCV RNA levels and SVR rates in 1529 mono‐infected and 176 HIV–HCV co‐infected patients treated with peginterferon alfa‐2a (40 kD) plus ribavirin. We improved the threshold for differentiating low and high viral load by fitting semiparametric generalized additive logistic regression models to the data and constructing receiver operating characteristics curves. Among HCV genotype 1 mono‐infected patients, the difference in SVR rates between those with low and high baseline HCV RNA levels was 27% (70%vs 43%) when 400 000 IU/mL was used and 16% (59%vs 43%) when 800 000 IU/mL was used. In HIV–HCV genotype 1 co‐infected patients, the difference was 51% (71%vs 20%) when 400 000 IU/mL was used and 43% (61%vs 18%) when 800 000 IU/mL was used. A lower threshold (200 000 IU/mL) was identified for genotype 1 mono‐infected patients with ‘normal’ alanine aminotransferase (ALT) levels. No threshold could be identified in HCV genotype 2 or 3 patients. A threshold HCV RNA level of 400 000 IU/mL is optimal for differentiating high and low probability of SVR in genotype 1‐infected individuals with elevated ALT.     

Factors associated with rapid and early virologic response to peginterferon alfa‐2a/ribavirin treatment in HCV genotype 1 patients representative of the general chronic hepatitis C population

Summary. Rapid virologic response (RVR) and complete early virologic response (cEVR) are associated with sustained virologic response to hepatitis C virus (HCV) therapy. We retrospectively examined baseline and on‐treatment factors associated with RVR (HCV RNA undetectable at week 4) and cEVR (HCV RNA undetectable at week 12, regardless of week 4 response). The analysis comprised 1550 HCV genotype‐1 patients from five clinical trials, including three enriched with difficult‐to‐treat populations, randomized to peginterferon alfa‐2a 180 μg/week plus ribavirin 1000–1200 mg/day. Overall, 15.6% achieved RVR and 54.0% achieved cEVR. Baseline factors predictive of RVR were serum HCV RNA ≤ 400 000 IU/mL (OR: 7.34; P < 0.0001), alanine aminotransferase >3 × ULN (OR: 2.01; P < 0.0001), non‐cirrhotic status (OR: 1.92; P = 0.0087), age ≤ 40 years (OR: 1.56; P = 0.0085), white non‐Latino ethnicity (OR: 1.41; P = 0.0666) and individual study (P < 0.0001). These factors plus body mass index ≤ 27 kg/m² were predictive of cEVR. After adjusting for these factors, mean on‐treatment ribavirin dose >13 mg/kg/day was predictive of RVR (OR: 1.69; P = 0.005) and cEVR (OR: 1.24; P = 0.09), whereas peginterferon alfa‐2a dose reduction was not. Greater decreases in haematologic parameters were observed in patients who achieved cEVR compared with patients who did not. In conclusion, several baseline and on‐treatment factors were associated with RVR and cEVR to peginterferon alfa‐2a plus ribavirin in difficult‐to‐treat HCV genotype‐1 patients, providing important prognostic information on the antiviral response in a patient cohort that is reflective of the general chronic hepatitis C population.