Clinical significance of detectable and quantifiable HCV RNA at the end of treatment with ledipasvir/sofosbuvir in GT1 patients

Does a detectable HCV RNA at the end of DAA therapy herald treatment failure?

BACKGROUND & AIMS

The study aimed to assess the phenomenon of achieving sustained virologic response (SVR) in patients with detectable ribonucleic acid (RNA) of hepatitis C virus (HCV) at the end of treatment (ET) with direct-acting antivirals (DAA), find how this is affected by the type of regimen, and how patients experiencing this differed from non-responders with detectable HCV RNA at the ET.

METHODS

The study included all consecutive patients with detectable HCV RNA at the ET selected from the EpiTer-2 database, a retrospective national multicentre project evaluating antiviral treatment in HCV-infected patients in 2015-2023.

RESULTS

Of the 16106 patients treated with IFN-free regimens with available HCV RNA assessment at the ET and at follow-up 12 weeks after treatment completion (FU), 1253 (7.8%) had detectable HCV RNA at the ET, and 1120 of them (89%) finally achieved SVR. This phenomenon was significantly more frequent in pangenotypic regimens, 10.3% vs. 4.7% in genotype-specific options (p < 0.001), and the highest proportion was documented for glecaprevir/pibrentasvir (13.7%), and velpatasvir/sofosbuvir ± ribavirin (6.9%). Patients ET + FU- treated with these two pangenotypic regimens (n = 668) had less advanced liver disease, were less frequently infected with genotype (GT) 3, and were significantly more likely to be treatment-naïve than 61 non-responders.

CONCLUSIONS

We documented 7.8% rate of patients with detectable HCV RNA at the ET, of whom 89% subsequently achieved SVR, significantly more frequently in the population treated with pangenotypic regimens. Less severe liver disease, more often GT3 infection, and a higher percentage of treatment-naive patients distinguished this group from non-responders.

Real-world experience for the outcomes and costs of treating hepatitis C patients: Results from the German Hepatitis C-Registry (DHC-R)

BACKGROUND & AIMS

With long-term consequences like the development of liver cirrhosis and hepatocellular carcinoma, chronic hepatitis C virus (HCV) infection is associated with a significant health burden. Information on HCV treatment outcomes and costs in routine care is still rare, especially for subgroups. The aim of this study was to analyse the treatment outcomes and costs of subgroups in routine care and to compare them over time with previous analyses.

METHODS

Data were derived from a noninterventional study including a subset of 10298 patients receiving DAAs with genotypes 1 and 3. Sociodemographic, clinical parameters and costs were collected using a web-based data recording system. The total sample was subdivided according to treatment regimen, cirrhosis status as well as present HIV infection and opioid substitution treatment (OST).

RESULTS

95% of all patients achieved SVR. Currently used DAA showed higher SVR-rates and less adverse events (AE) compared to former treatments. Concerning subgroups, cirrhotic patients, HIV-coinfected patients and OST patients showed lower but still high SVR-rates. In comparison, cirrhotic had considerably longer treatment duration and more frequent (serious) AE. Overall, average treatment costs were €48470 and costs per SVR were €51129; for currently used DAAs costs amounted to €30330 and costs per SVR to €31692. After the end of treatment, physical health is similar to the general population in all patients except cirrhotic. Mental health remains far behind in all subgroups, even for currently used DAA.

CONCLUSIONS

Over time, some relevant factors developed positively (SVR-rates, costs, treatment duration, adverse events, health-related quality of life (HRQoL)). Further research on HRQoL, especially on mental health, is necessary to evaluate the differences between subgroups and HRQoL over time and to identify influencing factors.

Meta-analysis: diagnostic accuracy of hepatitis C core antigen detection during therapy with direct-acting antivirals

BACKGROUND

Treatment of hepatitis C virus (HCV) infection with direct-acting antivirals (DAAs) is monitored by assessing plasma HCV-RNA load. However, detection of HCV core antigen (HCVcAg) may be an alternative.

AIM

To evaluate the diagnostic performance of the HCVcAg assay to monitor the efficacy of DAAs in HCV-infected patients METHODS: We performed searches in multiple electronic databases until 6 July 2022, of studies evaluating the HCVcAg detection in plasma or serum compared with the HCV-RNA test (gold standard). We calculated pooled measurement at 2 and 4 weeks of treatment, and at end-of-treatment (EOT), as well as sustained virological response (SVR; 12 weeks after EOT).

RESULTS

We selected 16 studies from 2016 to 2022, with 3237 patients and 8958 samples. Overall, the diagnostic performance and clinical utility of the HCVcAg assay were poor at week 2 (sensitivity = 0.40, specificity = 0.96, positive likelihood ratio (PLR) = 9.16, negative likelihood ratio (NLR) = 0.63, and area under the summary receiver operating curve (SROC) = 0.57), fair at week 4 (sensitivity = 0.30, specificity = 0.90, PLR = 3.18, NLR = 0.77, and AUC = 0.79), acceptable at EOT (sensitivity = 0.40, specificity =0.98, PLR = 16.54, NLR = 0.62, and AUC = 0.97) and excellent for SVR (sensitivity = 0.94, specificity = 0.99, PLR = 107.54, NLR = 0.06, and AUC = 0.99).

CONCLUSIONS

The HCVcAg assay may be helpful for monitoring the efficacy of HCV treatment with DAAs in HCV-infected patients at EOT and for documenting SVR, but not at weeks 2 and 4 of treatment due to poor diagnostic performance.

Immunological Characteristics of Patients Receiving Ultra-Short Treatment for Chronic Hepatitis C

Reducing the treatment duration for chronic hepatitis C could be an important tool in the effort to reach the elimination goals set by the World Health Organization. The current challenge is to predict the target group who will achieve sustained virological response at week 12 (SVR12) with shorter treatment duration. The aim of this exploratory study was to characterize immune subsets with focus on inhibitory receptors in patients who experienced SVR12 or virological relapse following four weeks treatment with glecaprevir/pibrentasvir with or without ribavirin. A total of 32 patients were included in this study of whom 21 achieved SVR12 and 11 had virological relapse. All available samples at baseline (n = 31) and end of treatment (EOT) (n = 30) were processed for flow cytometric analysis in order to measure the expression of PD-1, 2B4, BY55, CTLA-4, TIM-3 and LAG-3 on 12 distinct T cell subsets. At baseline, patients with SVR12 (n=21) had numerically lower frequencies of inhibitory receptors for 83% (60/72) of the investigated T-cell subtypes. The most significant difference observed between the two groups was a lower frequency of stem cell-like memory T-cells CD4⁺PD1⁺ in the SVR group (p = 0.007). Furthermore, we observed a significant positive correlation between baseline viral load and the expression of PD-1 on the total CD8⁺ T-cells and effector memory T-cells CD4⁺ and CD8⁺ for patients with virological relapse. This study suggests a measurable immunologic phenotype at baseline of patients achieving SVR12 after short treatment compared to patients with virological relapse.

Determining the lower limit of detection required for HCV viral load assay for test of cure following direct-acting antiviral-based treatment regimens: Evidence from a global data set

Achieving global elimination of hepatitis C virus requires a substantial scale-up of testing. Point-of-care HCV viral load assays are available as an alternative to laboratory-based assays to promote access in hard to reach or marginalized populations. The diagnostic performance and lower limit of detection are important attributes of these new assays for both diagnosis and test of cure. Therefore, our objective was to determine an acceptable LLoD for detectable HCV viraemia as a test for cure, 12 weeks post-treatment (SVR12). We assembled a global data set of patients with detectable viraemia at SVR12 from observational databases from 9 countries (Egypt, the United States, United Kingdom, Georgia, Ukraine, Myanmar, Cambodia, Pakistan, Mozambique) and two pharmaceutical-sponsored clinical trial registries. We examined the distribution of HCV viral load at SVR12 and presented the 90th, 95th, 97th and 99th percentiles. We used logistic regression to assess characteristics associated with low-level virological treatment failure (defined as <1000 IU/mL). There were 5973 cases of detectable viraemia at SVR12 from the combined data set. Median detectable HCV RNA at SVR12 was 287,986 IU/mL. The level of detection for the 95th percentile was 227 IU/mL (95% CI 170-276). Females and those with minimal fibrosis were more likely to experience low-level viraemia at SVR12 compared to men (adjusted odds ratio AOR = 1.60 95% confidence interval [CI] 1.30-1.97 and those with cirrhosis (AOR = 1.49 95% CI 1.15-1.93). In conclusion, an assay with a level of detection of 1000 IU/mL or greater may miss a proportion of those with low-level treatment failure.

Breakthroughs in hepatitis C research: from discovery to cure

In the 1970s, an unknown virus was suspected for documented cases of transfusion-associated hepatitis, a phenomenon called non-A, non-B hepatitis. In 1989, the infectious transmissible agent was identified and named hepatitis C virus (HCV) and, soon enough, the first diagnostic HCV antibody test was developed, which led to a dramatic decrease in new infections. Today, HCV infection remains a global health burden and a major cause of liver cirrhosis, hepatocellular carcinoma and liver transplantation. However, tremendous advances have been made over the decades, and HCV became the first curable, chronic viral infection. The introduction of direct antiviral agents revolutionized antiviral treatment, leading to viral eradication in more than 98% of all patients infected with HCV. This Perspective discusses the history of HCV research, which reads like a role model for successful translational research: starting from a clinical observation, specific therapeutic agents were developed, which finally were implemented in national and global elimination programmes.

Spontaneous Clearance After Relapse Following Direct-Acting Antiviral Treatment for Chronic HCV Infection

BACKGROUND & AIMS

Direct-acting antivirals (DAAs) cure most cases of chronic hepatitis C virus (HCV) infection. However, a small percentage of patients relapse with reappearance of viremia after a full course of therapy. Although most who relapse require retreatment, some patients spontaneously clear HCV without additional therapy. We studied patients who relapsed with detectable HCV RNA after a full course of DAA therapy and then spontaneously cleared the HCV infection without retreatment.

METHODS

We performed a case-control study of patients who spontaneously cleared chronic HCV infection following a documented relapse after DAA therapy at the Toronto Centre for Liver Disease, from January 2014 through December 2017. We collected clinical information at baseline, 12 weeks after treatment, and 6 months after relapse and compared data among spontaneous clearers, patients with persistent relapse, and patients who achieved a sustained virologic response to therapy 12 weeks after treatment (SVR12). The strength and breadth of interferon gamma cytokine secretion by HCV-specific T cells from peripheral blood were quantified using the ELISPOT assay.

RESULTS

Of the 1032 individuals with chronic HCV infection who were treated with DAAs, 93 patients had a documented relapse. Of these patients, 12 patients (13%) spontaneously cleared HCV within 6 months after the documented relapse without additional therapy. The spontaneous clearers had low levels of HCV RNA (<4 log IU/mL in 11 of 12) and normal levels of alanine aminotransferase at the time of relapse, much like patients with an SVR12. There was no significant difference between the spontaneous clearance group and the SVR12 group in magnitude and breadth of HCV-specific T cell responses.

CONCLUSIONS

In a case-control study of patients who spontaneously cleared chronic HCV infection following a relapse after DAA therapy, we found that it is important to confirm viremia prior to retreatment after the relapse-particularly for individuals with low levels of HCV RNA and normal or near-normal levels of alanine aminotransferase after treatment.

High Cure Rates for Hepatitis C Virus Genotype 6 in Advanced Liver Fibrosis With 12 Weeks Sofosbuvir and Daclatasvir: The Vietnam SEARCH Study

BACKGROUND

Genotype 6 is the most genetically diverse lineage of hepatitis C virus, and it predominates in Vietnam. It can be treated with sofosbuvir with daclatasvir (SOF/DCV), the least expensive treatment combination globally. In regional guidelines, longer treatment durations of SOF/DCV (24 weeks) are recommended for cirrhotic individuals, compared with other pangenotypic regimens (12 weeks), based on sparse data. Early on-treatment virological response may offer means of reducing length and cost of therapy in patients with liver fibrosis.

METHODS

In this prospective trial in Vietnam, genotype 6-infected adults with advanced liver fibrosis or compensated cirrhosis were treated with SOF/DCV. Day 14 viral load was used to guide duration of therapy: participants with viral load <500 IU/mL at day 14 were treated with 12 weeks of SOF/DCV and those ≥500 IU/mL received 24 weeks. Primary endpoint was sustained virological response (SVR).

RESULTS

Of 41 individuals with advanced fibrosis or compensated cirrhosis who commenced treatment, 51% had genotype 6a and 34% had 6e. The remainder had 6h, 6k, 6l, or 6o. One hundred percent had viral load <500 IU/mL by day 14, meaning that all received 12 weeks of SOF/DCV. One hundred percent achieved SVR12 despite a high frequency of putative NS5A inhibitor resistance-associated substitutions at baseline.

CONCLUSIONS

Prescribing 12 weeks of SOF/DCV results in excellent cure rates in this population. These data support the removal of costly genotyping in countries where genotype 3 prevalence is <5%, in keeping with World Health Organization guidelines. NS5A resistance-associated mutations in isolation do not affect efficacy of SOF/DCV therapy. Wider evaluation of response-guided therapy is warranted.

Prospective Multicenter Study of Early Antiviral Therapy in Liver and Kidney Transplant Recipients of HCV-Viremic Donors

BACKGROUND AND AIMS

Organs from hepatitis C virus (HCV)-viremic donors have been used in HCV-uninfected recipients (D+/R-), but the optimal treatment approach has not been defined. We evaluated the kinetics of HCV infection following transplant in D+/R- kidney-transplant (KT) and liver-transplant (LT) recipients when a preemptive antiviral strategy was used.

APPROACH AND RESULTS

Six US transplant programs prospectively treated D+/R- primary LT and KT recipients with sofosbuvir-velpastasvir for 12 weeks starting once viremia was confirmed following transplant and the patients were judged to be clinically stable, including estimated glomerular filtration rate >30 mL/min. Primary endpoints were sustained virologic response at 12 weeks following transplant and safety (assessed by proportion of treatment-related adverse and serious adverse events). Of the 24 patients transplanted (13 liver, of whom 2 had prior-treated HCV infection; 11 kidney), 23 became viremic after transplant. The median (interquartile range) time from transplant to start of antiviral therapy was 7.0 (6.0, 12.0) versus 16.5 (9.8, 24.5) days, and the median (interquartile range) HCV-RNA level 3 days after transplant was 6.5 (3.9, 7.1) versus 3.6 (2.9, 4.0) log₁₀  IU/mL in LT versus KT recipients, respectively. By week 4 of treatment, 10 of 13 (77%) LT, but only 2 of 10 (20%) KT, had undetectable HCV RNA (P = 0.01). At the end of treatment, all LT recipients were HCV RNA-undetectable, whereas 3 (30%) of the kidney recipients still had detectable, but not quantifiable, viremia. All achieved sustained virologic response at 12 weeks following transplant (lower 95% confidence interval bound: 85%). Serious adverse events considered possibly related to treatment were antibody-mediated rejection, biliary sclerosis, cardiomyopathy, and graft-versus-host disease, with the latter associated with multiorgan failure, premature treatment discontinuation, and death.

CONCLUSIONS

Despite differing kinetics of early HCV infection in liver versus non-liver recipients, a preemptive antiviral strategy is effective. Vigilance for adverse immunologic events is warranted.

Simplification of Care for Chronic Hepatitis C Virus Infection

In 2016, the World Health Organization (WHO) set a target for eliminating viral hepatitis as a major public health threat by 2030. However, while today's highly effective and well-tolerated pangenotypic direct-acting antiviral regimens have maximized simplification of hepatitis C virus (HCV) treatment, there remain a plethora of barriers to HCV screening, diagnosis, and linkage to care. As of 2017, only 19% of the estimated 71 million individuals living with chronic HCV worldwide were diagnosed and in 2015 to 2016, only 21% of diagnosed individuals had accessed treatment. Simplification and decentralization of the HCV care cascade would bolster patient engagement and support the considerable scale-up needed to achieve WHO targets. Recent developments in HCV screening and diagnosis, together with reduced pretreatment assessment and on-treatment monitoring requirements, can further streamline the care continuum, ensuring patients are linked to care quickly and earlier in the disease course, and minimize clinic visits.

Genome-wide capture sequencing to detect hepatitis C virus at the end of antiviral therapy

Background

Viral relapse is a major concern in hepatitis C virus (HCV) antiviral therapy. Currently, there are no satisfactory methods to predict viral relapse, especially in the era of direct acting antivirals in which the virus often quickly becomes undetectable using PCR-based approaches that focus on a small viral region. Next-generation sequencing (NGS) provides an alternative option for viral detection in a genome-wide manner. However, owing to the overwhelming dominance of human genetic content in clinical specimens, direct detection of HCV by NGS has a low sensitivity and hence viral enrichment is required.

Methods

Based on template-dependent multiple displacement amplification (tdMDA), an improved method for whole genome amplification (Wang et al., 2017. Biotechniques 63, 21–27), we evaluated two strategies to enhance the sensitivity of NGS-based HCV detection: duplex-specific nuclease (DSN)-mediated depletion of human sequences and HCV probe-based capture sequencing.

Results

In DSN-mediated depletion, human sequences were significantly reduced in the two HCV serum samples tested, 65.3% → 55.6% → 33.7% (#4727) and 68.6% → 56% → 21% (#4970), respectively for no normalization, self- and driver-applied normalization. However, this approach was associated with a loss of HCV sequences perhaps due to its micro-homology with the human genome. In capture sequencing, HCV-mapped sequencing reads occupied 96.8% (#4727) and 22.14% (#4970) in NGS data, equivalent to 1936x and 7380x enrichment, respectively. Capture sequencing was then applied to ten serum samples collected at the end of HCV antiviral therapy. Interestingly, the number of HCV-mapped reads was significantly higher in relapsed patients (n = 5) than those from patients with sustained virological response (SVR) (n = 5), 102.4 ± 72.3 vs. 2.6 ± 0.55, p = 0.014.

Conclusions

Our data provides concept evidence for a highly sensitive HCV detection by capture sequencing. The abundance difference of HCV sequencing reads at the end of HCV antiviral therapy could be applied to predict treatment outcomes.

Reversal of T Cell Exhaustion in Chronic HCV Infection

The long-term consequences of T cell responses’ impairment in chronic HCV infection are not entirely characterized, although they may be essential in the context of the clinical course of infection, re-infection, treatment-mediated viral clearance and vaccine design. Furthermore, it is unclear whether a complete reinvigoration of HCV-specific T cell response may be feasible. In most studies, attempting to reverse the effects of compromised immune response quality by specific blockades of negative immune regulators, a restoration of functional competence of HCV-specific T cells was shown. This implies that HCV-induced immune dysfunction may be reversible. The advent of highly successful, direct-acting antiviral treatment (DAA) for chronic HCV infection instigated investigation whether the treatment-driven elimination of viral antigens restores T cell function. Most of studies demonstrated that DAA treatment may result in at least partial restoration of T cell immune function. They also suggest that a complete restoration comparable to that seen after spontaneous viral clearance may not be attained, pointing out that long-term antigenic stimulation imprints an irreversible change on the T cell compartment. Understanding the mechanisms of HCV-induced immune dysfunction and barriers to immune restoration following viral clearance is of utmost importance to diminish the possible long-term consequences of chronic HCV infection.

Utility of the new cobas HCV test for viral load monitoring during direct-acting antiviral therapy

Background

The COBAS AmpliPrep/COBAS TaqMan assay HCV (CAP/CTM) is widely used in clinical routine for HCV testing. Recently, the new cobas HCV test was established for high throughput testing with minimal operator intervention. As different assays may yield different quantitative/qualitative results that possibly impact treatment decisions, the aim of this study was to externally evaluate the cobas HCV test performance in comparison to CAP/CTM in a clinically relevant setting.

Methods

Serum samples were obtained from 270 patients who received direct acting antiviral therapy with different treatment regimens at two study sites (Hannover and Frankfurt) in 2016. Overall, 1545 samples (baseline, on-treatment and follow-up) were tested in parallel by both assays.

Results

The mean difference between cobas HCV and CAP/CTM for the quantification of HCV RNA was 0.008 log₁₀ IU/ml HCV RNA (95% limits of agreement: -0.02–0.036) showing excellent agreement of both assays. With respect to clinical cut offs (HCV RNA detectable vs. target not detected and HCV RNA above the lower limit of quantification (LLOQ) vs. <LLOQ), discordant results were obtained in 9.5% and 4.6%, respectively; the greatest differences were observed during early stages of antiviral therapy (week 1, week 2 and week 4), but none were statistically significant. Overall percent agreement for SVR between cobas HCV and CAP/CTM at the 15 IU/ml cutoff was 99.2% (95%CI 92.7%-100%).

Conclusion

The performance of the new cobas HCV test was comparable to CAP/CTM in a clinical setting representing a large patient population with HCV GT 1 and 3 treated with DAAs.