Real‐world Australian data reflect very high sustained virologic response at 12 weeks with direct acting antiviral therapy for hepatitis C and suggests highly achievable even in those without an end‐of‐treatment response

There are limited real‐world data on the efficacy of direct acting antiviral (DAA) therapy for hepatitis C (HCV) in Australia. In this study, the efficacy of DAA therapy for HCV was compared between cirrhotic and non‐cirrhotic cohorts. Patients without end‐of‐treatment response (EoTR) were observed to ascertain likelihood of achieving sustained virological response at 12 weeks post‐treatment (SVR12). A total of 334 patients with HCV was included. Overall SVR12 was 96.7% with minimal differences in SVR12 between the cirrhosis and non‐cirrhosis groups (95.7 and 97.3%). There were 20 patients (5.99%) that failed to achieve an EoTR of which 80.0% (n = 16) went on to achieve SVR12. These results suggest DAA therapy is effective with high rates of SVR12 even in patients that do not achieve an EoTR.     

Augmentation of hepatitis C virus‐specific immunity and sustained virologic response

Treatment for chronic hepatitis C virus (HCV) infection has rapidly evolved into interferon‐free directly acting antiviral regimens (DAA) that result in high sustained virologic response. DAAs primarily work by suppressing HCV replication and rely less on the immune system than interferon‐based therapies. However, it is unclear whether the immune system recovers with suppression of HCV replication and contributes to HCV clearance with DAA therapy. We previously demonstrated HCV clearance is associated with increased HCV‐specific immunity in CHCV‐GT‐1‐infected patients during treatment with sofosbuvir (SOF)+ribavirin (RBV). Here, we aimed to analyse changes in HCV‐specific immunological responses associated with viral clearance with combination DAA therapy of SOF+ledipasvir (LDV) for 12 weeks in CHCV‐GT1 (N=14) patients who relapsed without augmentation of HCV‐specific immunity during treatment with SOF+RBV. Phenotypic and functional changes within the T‐cell compartment of PBMCs pre‐ and post‐treatment were analysed. Retreatment of relapsers with LDV/SOF resulted in all patients attaining SVR₁₂. Suppression of HCV was associated with a decline in T‐cell exhaustion markers (CD57; Tim3; PD1) along with augmented of HCV‐specific T‐cell IFN‐gamma responses post‐treatment. Addition of LDV to SOF was associated with augmentation of HCV‐specific immunity and SVR in patients who previously failed SOF+RBV therapy without increased immunity. These findings demonstrate a novel effect of DAA in inducing host immune responses to aid HCV clearance and achieve SVR.     

High rate of hepatitis C reinfection following antiviral treatment in the North East England Prisons

To achieve elimination of hepatitis C (HCV), a critical group to prioritise for diagnosis and treatment is the prison population, where HCV prevalence is high. A universal offer of blood‐borne virus testing (UOBBVT) programme and a new treatment pathway were introduced to seven North East England (NEE) Prisons. Our aim was to assess: (a) the proportion of individuals with active HCV commencing direct‐acting antivirals (DAAs); (b) the outcomes following DAA treatment; (3) the reinfection rate following sustained virological response (SVR). Data were collected prospectively on BBVT uptake, HCV positivity, HCV treatment outcomes and reinfection from March 2016 onwards. 8538 individuals had BBV testing. In total, 612 (7.2%) and 374 (4.4%) were HCV antibody positive and HCV RNA positive, respectively. Ultimately, 266 (71%) individuals commenced DAAs. Overall 111 achieved a documented SVR (42%), 17 (6%) failed treatment, 30 (11%) were still on treatment or had not reached 12 weeks post‐treatment at time of analysis, and 108 (41%) were lost to follow‐up. In those with a known outcome (n = 128), 87% achieved SVR. Worryingly, of those who achieved SVR, 21 (19%) were subsequently identified as having been reinfected (median time from SVR to documented reinfection 13 (range 7‐25) months). The reinfection rate was 0.406 cases per person‐year follow‐up. In conclusion, Implementation of a UOBBVT programme and new treatment pathway resulted in increased diagnosis and treatment of HCV in the NEE prison population. However, the high HCV reinfection rate suggests a need to improve harm reduction approaches.     

Adjuvant ribavirin and longer direct‐acting antiviral treatment duration improve sustained virological response among hepatitis C patients at risk of treatment failure

The role of ribavirin (RBV) in the era of direct‐acting antivirals (DAA) is not clear, and DAA studies have been largely genotype‐ and regimen‐specific. Using data from the Chronic Hepatitis Cohort Study, we evaluated the role of RBV and increased DAA treatment duration among patients with chronic hepatitis C (HCV) in routine clinical care. We performed multivariable analysis of data from 4133 patients receiving any of the following: sofosbuvir (SOF); daclatasvir + SOF; grazoprevir + elbasvir; paritaprevir/ritonavir + ombitasvir; simeprevir + SOF; and SOF + ledipasvir; SOF + velpatasvir ± voxilaprevir; and glecaprevir + pibrentasvir—all with/ without RBV. Inverse probability treatment weighting was used to adjust for treatment selection bias. Sustained virological response (SVR) was defined by undetectable HCV RNA 12 weeks after end of therapy. The overall SVR rate was 95%. Mean treatment duration was 12 ± 4.5 weeks. The final model included treatment duration and diabetes, as well as the interaction of RBV with previous treatment status (treatment naïve, interferon treatment failure [TF] or previous DAA TF), cirrhosis status, and HCV genotype (GT). Each one‐month increment of treatment duration increased odds of SVR by 99% (aOR = 1.99). Diabetes, previous DAA TF, and decompensated cirrhosis significantly reduced odds of SVR. RBV significantly increased the likelihood of SVR among patients with decompensated cirrhosis (aOR = 5.05), previous DAA treatment failure (aOR = 5.43), and GT3 (aOR = 13.28). Among RBV‐free regimens, patients with GT3 were less likely to achieve SVR than those with GT1 or 2 (aOR 0.07). Diabetes, decompensated cirrhosis, and prior DAA TF independently reduced the likelihood of SVR. Longer treatment duration increased likelihood of SVR. Conclusion: RBV increased likelihood of SVR among patients with GT3, previous DAA TF, or decompensated cirrhosis.     

The impact of SVR from direct‐acting antiviral‐ and interferon‐based treatments for HCV on hepatocellular carcinoma risk

We evaluated the effect of sustained virologic response (SVR) from direct‐acting antiviral (DAA)‐ and interferon‐based treatments on hepatocellular carcinoma (HCC) risk in a large population‐based cohort in Canada. We used data from the BC Hepatitis Testers Cohort, which includes ~1.3 million individuals tested for HCV since 1990, linked with healthcare administrative and registry datasets. Patients were followed from the end of HCV treatment to HCC, death or 31 December 2016. We assessed HCC risk among those who did and did not achieve SVR by treatment type using proportional hazard models. Of 12 776 eligible individuals, 3905 received DAAs while 8871 received interferon‐based treatments, followed for a median of 1.0 [range: 0.6‐2.7] and 7.9 [range: 4.4‐17.1] years, respectively. A total of 3613 and 6575 achieved SVR with DAAs‐ and interferon‐based treatments, respectively. Among DAAs‐treated patients, HCC incidence rate was 6.9 (95%CI: 4.7‐10.1)/1000 person yr (PY) in SVR group (HCC cases: 26) and 38.2 (95%CI: 20.6‐71.0) in the no‐SVR group (HCC cases: 10, P < .001). Among interferon‐treated individuals, HCC incidence rate was 1.8 (95%CI: 1.5‐2.2) in the SVR (HCC cases: 99) and 13.9 (95%CI: 12.3‐15.8) in the no‐SVR group (HCC cases: 239, P < .001). Compared with no‐SVR from interferon, SVR from DAA‐ and interferon‐based treatments resulted in significant reduction in HCC risk (adjusted subdistribution hazard ratio (adjSHR) DAA = 0.30, 95%CI: 0.19‐0.48 and adjSHR interferon = 0.2, 95%CI: 0.16‐0.26). Among those with SVR, treatment with DAAs compared to interferon was not associated with HCC risk (adjSHR = 0.93, 95%CI: 0.51‐1.71). In conclusion, similar to interferon era, DAA‐related SVR is associated with 70% reduction in HCC risk.     

Prevention of allograft HCV recurrence with peri‐transplant human monoclonal antibody MBL‐HCV1 combined with a single oral direct‐acting antiviral: A proof‐of‐concept study

Patients with active hepatitis C virus (HCV) infection at transplantation experience rapid allograft infection, increased risk of graft failure and accelerated fibrosis. MBL‐HCV1, a neutralizing human monoclonal antibody (mAb) targeting the HCV envelope, was combined with a licensed oral direct‐acting antiviral (DAA) to prevent HCV recurrence post‐transplant in an open‐label exploratory efficacy trial. Eight subjects received MBL‐HCV1 beginning on the day of transplant with telaprevir initiated between days 3 and 7 post‐transplantation. Following FDA approval of sofosbuvir, two subjects received MBL‐HCV1 starting on the day of transplant with sofosbuvir initiated on day 3. Combination treatment was administered for 8‐12 weeks or until the stopping rule for viral rebound was met. The primary endpoint was undetectable HCV RNA at day 56 with exploratory endpoints of sustained virologic response (SVR) at 12 and 24 weeks post‐treatment. Both subjects receiving mAb and sofosbuvir achieved SVR24. Four of eight subjects in the mAb and telaprevir group met the primary endpoint; one subject achieved SVR24 and three subjects relapsed 2‐12 weeks post‐treatment. The other four subjects experienced viral breakthrough. There were no serious adverse events related to study treatment. This proof‐of‐concept study demonstrates that peri‐transplant immunoprophylaxis combined with a single oral direct‐acting antiviral in the immediate post‐transplant period can prevent HCV recurrence.     

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.     

Dynamic changes in innate immune responses during direct‐acting antiviral therapy for HCV infection

The role of the endogenous interferon (IFN) system has been well characterized during IFN‐based therapy for chronic hepatitis C virus (HCV) infection; less is known for direct‐acting antivirals (DAAs). In this phase 3b open‐label study, we assessed changes in IFN‐stimulated genes (ISGs) in non‐cirrhotic treatment‐naïve or pegIFN/RBV‐experienced HCV‐GT1a‐infected patients receiving paritaprevir/ritonavir/ombitasvir + dasabuvir + ribavirin (PrOD + R) for 12 weeks. ISG expression was quantified from peripheral blood mononuclear cells at baseline, treatment weeks (TW)2, TW4, TW8, end of treatment (EOT) and at post‐treatment week 12. Paired sera were used to assess IFN‐α/IFN‐related chemokines/cytokines. Twenty‐five patients were enrolled. Overall sustained virologic response (SVR)12 was 92% (no virologic failure [VF]) and 100% for those completing the study protocol. Two patients were excluded from the ISG analysis due to lack of post‐treatment samples. The majority of ISGs were downregulated at TW2‐TW4 (nadir TW4); however, a relative increase was observed at TW8‐EOT, although levels were lower than baseline. This downregulation was accompanied by increases in IFN‐α/IFN‐related chemokines, a finding not observed with T_H1/2‐related cytokines. Following SVR, ISG expression returned to TW2 levels. In conclusion, PrOD + R for 12 weeks was well‐tolerated with no VF. Our data demonstrate dynamic alterations in innate immune profiles during highly potent IFN‐free DAA therapy. The downregulation of ISG post‐therapy suggests reversal of the “exhausted” ISG phenotype following SVR, and the rise in ISGs and IFN‐α/IFN‐responsive chemokines late during therapy suggests resetting of IFN responsiveness that may be relevant in determining duration of or immunological sequelae from DAA therapy, including HBV reactivation.     

Characterization of changes in intrahepatic immune cell populations during HCV treatment with sofosbuvir and ribavirin

Treatment of chronic hepatitis C virus (HCV) infection with direct‐acting antivirals (DAAs) results in a sustained virologic response (SVR) in most patients. While highly efficacious, ~3%‐5% of patients do not achieve SVR despite having virus that appears susceptible. It is unclear whether host factors contribute to treatment failures, although innate and adaptive immunity may play a role. Previous studies showed that after DAA treatment, the composition of intrahepatic immune cells does not normalize relative to healthy volunteers, even in cases where SVR is achieved. We used paired pre‐ and post‐treatment liver biopsies from 13 patients treated with sofosbuvir and ribavirin, 4 of whom relapsed, to analyse intracellular immune changes during DAA treatment and explore correlations with inflammation and treatment outcome. We performed single marker immunohistochemistry followed by electronic image capture, manual annotation of parenchymal and non‐parenchymal regions, and quantitative image analysis. The predominant cellular change during treatment was a decrease in CD8+ cellular density in both parenchymal and non‐parenchymal regions. CD68+ Kupffer cell density correlated with hepatic inflammation (AST, ALT) pre‐treatment, but did not change during treatment. CD4+ cellular density decreased in non‐parenchymal regions and, intriguingly, was lower pre‐treatment in subjects who eventually relapsed. Other cellular markers (CD56, CD20), as well as markers of apoptosis (TIA‐1) and activated stellate cells, did not change significantly during treatment or differ by treatment outcome. The predominant intrahepatic cellular change during DAA treatment of chronic HCV infection is a reduction in CD8+ cellular density, but this did not correlate with treatment outcome.     

Real‐world effectiveness of glecaprevir/pibrentasvir and ledipasvir/sofosbuvir for mixed genotype hepatitis C infection: A multicenter pooled analysis in Taiwan

Data on direct‐acting antiviral agent (DAA) treatment for mixed genotype hepatitis C virus (HCV) infection are scant. This study examined the effectiveness of glecaprevir/pibrentasvir (GLE/PIB) and ledipasvir/sofosbuvir (LDV/SOF) for mixed HCV genotype infection in a real‐world setting in Taiwan. We analysed the data from all patients with mixed HCV genotype infections treated with GLE/PIB or LDV/SOF from 2017 to 2019 in three Chang Gung Memorial Hospitals in Taiwan. The primary treatment outcome was sustained virologic response 12 weeks after treatment cessation (SVR12). Adverse events (AEs) were also evaluated. A total of 5190 HCV patients received DAA treatment during this time period. Among them, 116 patients (2.2%) had mixed infections of any 2 or 3 genotypes of 1a, 1b, 2, 3 and 6. Fifty‐four patients received GLE/PIB and 62 received LDV/SOF. SVR12 rates for LDV/SOF vs GLE/PIB therapy were 96.6% (56/58) vs 100% (51/51) by the per‐protocol analysis and 90.3% (56/62) vs 94.4% (51/54) by the evaluable population analysis. Two patients with 1b + 6 and 1b + 2 genotype infections in the LDV/SOF group had relapse. Evaluating the GLE/PIB vs LDV/SOF groups for the most common AEs revealed pruritus (16.7% vs 4.8%), abdominal discomfort (5.6% vs 8%) and fatigue (5.6% vs 4.8%). One patient with AE‐related treatment discontinuation presented with liver decompensation after 4‐week GLE/PIB therapy. DAA‐related significant laboratory abnormalities occurred in two patients with >3× elevated bilirubin level in the GLE/PIB group. GLE/PIB and LDV/SOF are well tolerated and achieve high SVR12 rates for patients with mixed HCV genotype infection.     

Efficacy of generic oral directly acting agents in patients with hepatitis C virus infection

Novel direct‐acting antivirals (DAAs) are now the standard of care for the management of hepatitis C virus (HCV) infection. Branded DAAs are associated with high sustained virological response at 12 weeks post‐completion of therapy (SVR12), but are costly. We aimed to assess the efficacy of generic oral DAAs in a real‐life clinical scenario. Consecutive patients with known HCV infection who were treated with generic‐oral DAA regimens (May 2015 to January 2017) were included. Demographic details, prior therapy and SVR12 were documented. Four hundred and ninety patients (mean age: 38.9 ± 12.7 years) were treated with generic DAAs in the study time period. Their clinical presentations included chronic hepatitis (CHC) in 339 (69.2%) of cases, compensated cirrhosis in 120 (24.48%) cases and decompensated cirrhosis in 31 (6.32%) cases. Genotype 3 was most common (n = 372, 75.9%) followed by genotype 1 (n = 97, 19.8%). Treatment naïve and treatment‐experienced (defined as having previous treatment with peginterferon and ribavirin) were 432 (88.2%) and 58 (11.8%), respectively. Generic DAA treatment regimens included sofosbuvir in combination with ribavirin (n = 175), daclatasvir alone (n = 149), ribavirin and peginterferon (n = 80), ledipasvir alone (n = 43), daclatasvir and ribavirin (n = 37), and ledipasvir and ribavirin (n = 6). Overall SVR12 was 95.9% (470/490) for all treatment regimens. SVR12 for treatment naïve and experienced patients was 97.0% (419/432) and 87.9% (51/58), respectively, P = .005. High SVR12 was observed with various regimens, irrespective of genotype and underlying liver disease status. There were no differences in SVR12 with 12 or 24 weeks therapy. No major adverse event occurred requiring treatment stoppage. Generic oral DAAs are associated with high SVR rates in patients with HCV infection in a real‐life clinical scenario.     

Evolution of HCV associated porphyria cutanea tarda after HCV sustained virologic response by direct acting antivirals

ObjectivesPorphyria cutanea tarda (PCT) is common and usually associated with HCV chronic infection and HFE polymorphisms. Since DAA IFN-free regimens availability, SVR for HCV is nearly a constant and we wonder whether HCV SVR determine PCT evolution.MethodsRetrospective observational study including patients with HCV associated PCT from the Gastroenterology and Infectious Diseases Departments at our Hospital, treated with DAA (Apr/2015–Apr/2017). Clinical variables of PCT were collected at PCT diagnosis, after PCT treatment, before DAA use and after SVR achievement. UROD activity and C282Y/H63D polymorphisms were registered. SPSS 22.0.Results13 HCV-PCT patients included: median age 52.5 years; 4 females; 8 HCV/HIV co-infected (all on undetectable viral load). Classical PCT factors: 12 smoked, 9 alcohol abuse, 6 former IDU. 10 type I PCT and 1 type II PCT. HFE polymorphism: 2 cases with C282Y/H63D; H63D polymorphism in 8. PCT manifestations resolved with PCT treatment in 4 patients, almost completely in 7 patients, 1 patient referred stabilization and one worsened. After DAA treatment all the residual lesions resolved, what always led to specific treatment interruption.ConclusionsOur series of cases of HCV-associated PCT shows that SVR after DAA treatment leads to PCT resolution. Porphyrin levels are not needed after ending PCT specific treatment interruption when there are no residual skin lesions in HCV-associated PCT.     

Safety and efficacy of direct‐acting antivirals for the treatment of chronic hepatitis C in a real‐world population aged 65 years and older

The availability of direct‐acting antiviral agents (DAA) regimens has expanded the pool of patients eligible for treatment. However, data on the virologic response and tolerability of DAAs in elderly patients are lacking. We evaluated the efficacy and safety of DAAs in patients with advanced fibrosis/cirrhosis in real‐life practice with the focus on those aged ≥65 years. Between January and December 2015, all consecutive patients with HCV‐related advanced fibrosis/cirrhosis treated with DAA at eleven tertiary referral centres in Emilia Romagna (Italy) were enrolled. Regimen choice was based on viral genotype and stage of disease, according to guidelines. The primary end point was sustained virologic response 12 weeks after the end of treatment (SVR12). Overall, 282 of 556 (50.7%) patients evaluated were elderly, most of them with cirrhosis. Antiviral therapy was stopped prematurely in four (1.4%) patients. Two patients, both with cirrhosis, died during treatment due to worsening of liver/renal function. SVR12 was achieved by 94.7% and was comparable to that obtained in patients aged <65 (P=.074). Similar data were also reported in subgroup of patients aged ≥75 years. All patients with advanced fibrosis achieved virologic response. SVR12 was 80.8% in Child‐Pugh‐Turcotte (CTP)‐B cirrhosis and 95.4% in CTP‐A (P=.013). According to genotype, the SVR12 was achieved in 172 of 181 (95%) with genotype 1b cirrhosis and in 44 of 48 (91.7%) with genotype 2 cirrhosis. In conclusions, in a real‐world setting, DAAs are safe and effective in elderly patients with HCV‐related advanced fibrosis/cirrhosis, but SVR12 is lower with worsening CTP class.     

Similar recovery of liver function after response to all‐oral HCV therapy in patients with cirrhosis with and without HIV coinfection

Among patients with cirrhosis, recovery of liver function after SVR to all‐oral direct‐acting antivirals (DAA) in HIV/HCV coinfection could be different to that in HCV monoinfection. Because of this, we compared the changes in several markers of liver function between HCV‐monoinfected and HIV/HCV‐coinfected patients with cirrhosis who achieved SVR12 to DAA combinations. In this retrospective cohort study, cirrhotics included in the HEPAVIR‐DAA and GEHEP‐MONO cohorts were selected if they had SVR12 to all‐oral DAAs. Patients treated with atazanavir were excluded. Liver function improvement was defined as Child‐Pugh‐Turcotte (CPT) decrease ≥1 and/or MELD decrease ≥2 between baseline and SVR12. Liver function worsening was defined as a CPT increase ≥1 and/or MELD increase ≥2 and/or decompensations between baseline and SVR12. We included 490 patients, 270 (55%) of them with HIV coinfection. Liver function improved in 50 (56%) HCV‐infected individuals and in 82 (57%) HIV/HCV‐coinfected patients (P = 0.835). Liver function worsened in 33 (15%) HCV‐monoinfected patients and in 33 (13%) HIV/HCV‐coinfected patients (P = 0.370). Factors independently related with liver function improvement were male gender [adjusted OR (AOR) 2.1 (95% confidence interval, 95% CI: 1.03‐4.2), P = 0.040], bilirubin < 1.2 mg/dL (AOR 1.8 [95% CI: 1.004‐3.3], P = 0.49), and INR < 1.3 (AOR 2.4 [95% CI: 1.2‐5.0], P = 0.019) at baseline. After multivariate analysis, albumin < 3.5 g/dL was associated with liver function worsening (AOR 6.1 [95% CI: 3‐12.5], P < 0.001). Liver function worsening and improvement rates after responding to DAA are similar among HCV‐monoinfected and HIV/HCV‐coinfected cirrhotics. Gender, INR, bilirubin, and albumin levels were associated with liver function changes after response to DAAs.     

IFN‐free therapy is associated with restoration of type I IFN response in HIV‐1 patients with acute HCV infection who achieve SVR

Interferon (IFN)‐free direct‐acting antiviral agents (DAAs) have revolutionized chronic hepatitis C virus (HCV) treatment; early studies suggest excellent efficacy in acute HCV. However, changes in innate immune responses during DAA therapy for acute HCV are unknown. We studied interferon‐stimulated gene (ISG) expression and related cytokines/chemokines in HIV‐infected patients with acute HCV receiving sofosbuvir plus ribavirin (SOF+RBV) as part of the A5327 clinical trial. ISG expression was determined from PBMCs, and circulating cytokines/chemokines were quantified from serum from study participants. The overall sustained virologic response (SVR) was 57%; all treatment failures were due to virologic relapse. Apart from NOS2a, baseline ISG/chemokine/cytokine levels were similar irrespective of treatment outcome. Downregulation of ISGs was observed at treatment week four and end of treatment (EOT), implicating HCV in establishing elevated ISGs early during HCV infection. Levels of many of these ISGs increased at post‐treatment week 12 (PTW12) in relapsers only, coinciding with recurrent HCV RNA. Eleven ISGs were differentially expressed in responders vs relapsers. On‐treatment viral suppression was also associated with a reduction in IP‐10, CXCL11 and MIP‐1β levels. In contrast, circulating IFN‐α levels were significantly higher at EOT and PTW12 in responders vs relapsers. Upregulation of peripheral ISG expression is established early in the course of HCV infection during acute HCV infection, but did not predict subsequent treatment outcome with SOF+RBV. ISGs were downregulated during therapy and increased post‐therapy in relapsers. IFN‐α levels were higher in responders at EOT/PTW12, suggesting that impaired type I IFN production/secretion may contribute to relapse.     

Treatment adherence and support for people who inject drugs taking direct‐acting antiviral therapy for hepatitis C infection

A community‐based public health facility in Sydney, Australia, the Kirketon Road Centre (KRC), provides health care to people who inject drugs (PWID), homeless and other marginalized people. Since March 2016, KRC has provided treatment for chronic hepatitis C virus (HCV) with direct‐acting antivirals (DAAs). We aimed to evaluate treatment adherence amongst clients taking DAAs in a highly marginalized population. All clients who commenced DAA therapy prior to March 2018 at KRC were included in this observational cohort with a subset of clients attending daily or weekly for enhanced adherence support and dosing. Demographic, behavioural, clinical measures and medication dosing were recorded, and adherence was calculated as the proportion of doses taken during the expected treatment duration. Factors associated with adherence were examined using logistic regression. A total of 242 individuals commenced DAA therapy, of whom 79 (32%) received enhanced adherence support. Enhanced support was associated with homelessness, daily injecting, Aboriginality, mental health co‐morbidity and poly‐drug use (all P < .001). Overall adherence was 86%, and 92% of patients missed one or more doses (median 10, IQR 4‐24). At least 90% adherence during planned duration was seen in 38%, but increased to 66% by continuing therapy beyond planned duration. Intention‐to‐treat SVR12 was 68% and 66% in the enhanced adherence support sub‐population, with 29% lost to follow‐up by SVR12 testing. There were only 2 (0.8%) documented virological failures. Per‐protocol SVR12 was 99% and 96% in the enhanced adherence support sub‐population. In conclusion, adherence support may benefit those with multiple markers of marginalization. Extension of therapy beyond planned duration is a pragmatic strategy to enhance completion. Strategies to improve follow‐up, particularly post‐treatment are required.