Phase 2b trial of interferon-free therapy for hepatitis C virus genotype 1

crVDAC3 alleviates ferroptosis by impeding HSPB1 ubiquitination and confers trastuzumab deruxtecan resistance in HER2-low breast cancer

AIMS

With the wide application of trastuzumab deruxtecan (T-DXd), the survival of HER2-low breast cancer patients is dramatically improved. However, resistance to T-DXd still exists in a subset of patients, and the molecular mechanism remains unclear.

METHODS

An in vivo shRNA lentiviral library functional screening was performed to identify potential circular RNA (crRNA) that mediates T-DXd resistance. RNA pull-down, mass spectrometry, RNA immunoprecipitation, and co-immunoprecipitation assays were conducted to investigate the molecular mechanism. Ferroptosis was detected using C11-BODIPY, Liperfluo, FerroOrange staining, glutathione quantification, malondialdehyde quantification, and transmission electron microscopy. Molecular docking, virtual screening, and patient-derived xenograft (PDX) models were used to validate therapeutic agents.

RESULTS

VDAC3-derived crRNA (crVDAC3) ranked first in functional shRNA library screening. Knockdown of crVDAC3 increased the sensitivity of HER2-low breast cancer cells to T-DXd treatment. Further mechanistic research revealed that crVDAC3 specifically binds to HSPB1 protein and inhibits its ubiquitination degradation, leading to intracellular accumulation and increased levels of HSPB1 protein. Notably, suppression of crVDAC3 dramatically increases excessive ROS levels and labile iron pool accumulation. Inhibition of crVDAC3 induces ferroptosis in breast cancer cells by reducing HSPB1 expression, thereby mediating T-DXd resistance. Through virtual screening and experimental validation, we identified that paritaprevir could effectively bind to crVDAC3 and prevent its interaction with HSPB1 protein, thereby increasing ubiquitination degradation of HSPB1 protein to overcome T-DXd resistance. Finally, we validated the enhanced therapeutic efficacy of T-DXd by paritaprevir in a HER2-low PDX model.

CONCLUSION

This finding reveals the molecular mechanisms underlying T-DXd resistance in HER2-low breast cancer. Our study provides a new strategy to overcome T-DXd resistance by inhibiting the interaction between crVDAC3 and HSPB1 protein.

Enhanced liver fibrosis score as a noninvasive biomarker in hepatitis C virus patients after direct-acting antiviral agents

Background: In more than 90% of chronic viral hepatitis C (HCV) patients treated with direct-acting antiviral agents (DAAs), a sustained viral response (SVR) was observed. Unfortunately, there are subgroups of subjects who display enduring liver fibrosis and are at high risk of developing hepatocellular carcinoma (HCC). Thus, liver fibrosis evaluation during the follow-up of these patients plays a pivotal role. The gold standard to evaluate hepatic fibrosis is liver biopsy, which is an invasive procedure. Imaging techniques and serum biomarkers have been proposed as safer and cheaper procedures.

Objectives: In this study, we evaluated the concordance of transient elastography (TE) with ELF score ( enhanced liver fibrosis) in a cohort of patients with HCV before and after direct-acting antiviral (DAAs) treatment. ELF score has been validated in other chronic liver diseases; the evidence is not available in HCV patients treated with DAAs.

Study design: We prospectively recruited all consecutive HCV patient candidates for DAAs therapy at the University of Naples “Federico II” between April 2015 and July 2016. TE and ELF scores were assessed at baseline, at SVR24, and at SVR48.

Results: One-hundred-nineteen patients were treated with DAAs, and 94.1% of them reached SVR. A total of 55.5% of patients were males with a mean age of 64.7 ± 9.6 years. TE results revealed that 12 patients (10%) had F1-2 mild/moderate fibrosis, and 107 (90%) had F3-4 advanced fibrosis. At baseline, SVR24, and SVR48, the concordance between ELF test and TE was poor: 0.11 (p = 0.086), 0.15 (p = 0.124), and 0.034 (p = 0.002), respectively. However, at SVR24 and SVR48, both methods showed a significant amelioration of liver fibrosis compared to baseline (p < 0.001). In addition, both ELF index and TE were significantly associated with portal hypertension at baseline, but not with varices and ascites.

Conclusions: Our findings suggested that ELF test could predict changes in liver fibrosis, independently of TE. In case of TE unavailability, ELF score could represent an appropriate tool. Notably, in the context of the COVID-19 pandemic, ELF testing should be encouraged to reduce unnecessary access to the hospital and prolonged physical contact.

National Brazilian survey on the outcomes of hepatitis c retreatment in patients non-responders to direct antiviral agents

BACKGROUND AND AIMS

Treatment of hepatitis C with direct antiviral agents (DAA) is associated with almost 95% of sustained virological response. However, some patients need retreatment. In Brazil, it should be done according to the Ministry of Health guidelines, frequently updated to include newly available drugs. This study aimed to conduct a national survey about the characteristics and outcomes of retreatment of hepatitis C in previously non-responders to DAAs.

PATIENTS AND METHODS

Institutions from all over the country were invited to participate in a national registry for retreatment, including information about clinical and epidemiological characteristics of the patients, type and outcomes of retreatment regimens. Only patients previously treated with interferon-free regimens were included.

RESULTS

As previous treatments the distribution was: SOF/DCV (56%), SOF/SIM (22%), 3D (11%), SOF/LED (6%) and SOF/RBV (5%). For retreatment the most frequently used drugs were SOF/GP (46%), SOF/DCV (23%) and SOF/VEL (11%). From 159 patients retreated, 132/159 (83%) had complete information in the registry and among them only seven patients were non-responders (SVR of 94.6%). All retreatments were well tolerated, without any serious adverse events or interruptions.

CONCLUSION

The retreatment of patients previously non-responders to DAAs was associated with high rate of SVR in this sample of Brazilian patients. This finding allows us to conclude that the retreatment options available in the public health system in Brazil are effective and safe and are an important component of the strategy of elimination of hepatitis C in our country.

Main protease inhibitors and drug surface hotspots for the treatment of COVID-19: A drug repurposing and molecular docking approach

Here, drug repurposing and molecular docking were employed to screen approved MPP inhibitors and their derivatives to suggest a specific therapeutic agent for the treatment of COVID-19. The approved MPP inhibitors against HIV and HCV were prioritized, while RNA dependent RNA Polymerase (RdRp) inhibitor remdesivir including Favipiravir, alpha-ketoamide were studied as control groups. The target drug surface hotspot was also investigated through the molecular docking technique. Molecular dynamics was performed to determine the binding stability of docked complexes. Absorption, distribution, metabolism, and excretion analysis was conducted to understand the pharmacokinetics and drug-likeness of the screened MPP inhibitors. The results of the study revealed that Paritaprevir (-10.9 kcal/mol) and its analog (CID 131982844) (-16.3 kcal/mol) showed better binding affinity than the approved MPP inhibitors compared in this study, including remdesivir, Favipiravir, and alpha-ketoamide. A comparative study among the screened putative MPP inhibitors revealed that the amino acids T25, T26, H41, M49, L141, N142, G143, C145, H164, M165, E166, D187, R188, and Q189 are at potentially critical positions for being surface hotspots in the MPP of SARS-CoV-2. The top 5 predicted drugs (Paritaprevir, Glecaprevir, Nelfinavir, and Lopinavir) and the topmost analog showed conformational stability in the active site of the SARS-CoV-2 MP protein. The study also suggested that Paritaprevir and its analog (CID 131982844) might be effective against SARS-CoV-2. The current findings are limited to in silico analysis and lack in vivo efficacy testing; thus, we strongly recommend a quick assessment of Paritaprevir and its analog (CID 131982844) in a clinical trial.

Strategic treatment optimization for HCV (STOPHCV1): a randomised controlled trial of ultrashort duration therapy for chronic hepatitis C

Background: The World Health Organization (WHO) has identified the need for a better understanding of which patients with hepatitis C virus (HCV) can be cured with ultrashort course HCV therapy. Methods: A total of 202 individuals with chronic HCV were randomised to fixed-duration shortened therapy (8 weeks) vs variable-duration ultrashort strategies (VUS1/2). Participants not cured following first-line treatment were retreated with 12 weeks' sofosbuvir/ledipasvir/ribavirin. The primary outcome was sustained virological response 12 weeks (SVR12) after first-line treatment and retreatment. Participants were factorially randomised to receive ribavirin with first-line treatment. Results: All evaluable participants achieved SVR12 overall (197/197, 100% [95% CI 98-100]) demonstrating non-inferiority between fixed-duration and variable-duration strategies (difference 0% [95% CI -3.8%, +3.7%], 4% pre-specified non-inferiority margin). First-line SVR12 was 91% [86%-97%] (92/101) for fixed-duration vs 48% [39%-57%] (47/98) for variable-duration, but was significantly higher for VUS2 (72% [56%-87%] (23/32)) than VUS1 (36% [25%-48%] (24/66)). Overall, first-line SVR12 was 72% [65%-78%] (70/101) without ribavirin and 68% [61%-76%] (69/98) with ribavirin (p=0.48). At treatment failure, the emergence of viral resistance was lower with ribavirin (12% [2%-30%] (3/26)) than without (38% [21%-58%] (11/29), p=0.01). Conclusions: Unsuccessful first-line short-course therapy did not compromise retreatment with sofosbuvir/ledipasvir/ribavirin (100% SVR12). SVR12 rates were significantly increased when ultrashort treatment varied between 4-7 weeks rather than 4-6 weeks. Ribavirin significantly reduced resistance emergence in those failing first-line therapy. ISRCTN Registration: 37915093 (11/04/2016).

Strategic treatment optimization for HCV (STOPHCV1): a randomised controlled trial of ultrashort duration therapy for chronic hepatitis C

Background: The world health organization (WHO) has identified the need for a better understanding of which patients with hepatitis C virus (HCV) can be cured with ultrashort course HCV therapy. Methods: A total of 202 individuals with chronic HCV were randomised to fixed-duration shortened therapy (8 weeks) vs variable-duration ultrashort strategies (VUS1/2). Participants not cured following first-line treatment were retreated with 12 weeks' sofosbuvir/ledipasvir/ribavirin. The primary outcome was sustained virological response 12 weeks (SVR12) after first-line treatment and retreatment. Participants were factorially randomised to receive ribavirin with first-line treatment. Results: All evaluable participants achieved SVR12 overall (197/197, 100% [95% CI 98-100]) demonstrating non-inferiority between fixed-duration and variable-duration strategies (difference 0% [95% CI -3.8%, +3.7%], 4% pre-specified non-inferiority margin). First-line SVR12 was 91% [86%-97%] (92/101) for fixed-duration vs 48% [39%-57%] (47/98) for variable-duration, but was significantly higher for VUS2 (72% [56%-87%] (23/32)) than VUS1 (36% [25%-48%] (24/66)). Overall, first-line SVR12 was 72% [65%-78%] (70/101) without ribavirin and 68% [61%-76%] (69/98) with ribavirin (p=0.48). At treatment failure, the emergence of viral resistance was lower with ribavirin (12% [2%-30%] (3/26)) than without (38% [21%-58%] (11/29), p=0.01). Conclusions: Unsuccessful first-line short-course therapy did not compromise retreatment with sofosbuvir/ledipasvir/ribavirin (100% SVR12). SVR12 rates were significantly increased when ultrashort treatment varied between 4-7 weeks rather than 4-6 weeks. Ribavirin significantly reduced resistance emergence in those failing first-line therapy. ISRCTN Registration: 37915093 (11/04/2016).

Liver Pathologic Changes After Direct-Acting Antiviral Agent Therapy and Sustained Virologic Response in the Setting of Chronic Hepatitis C Virus Infection

CONTEXT.—

Treatment of chronic viral hepatitis C (HCV) infection with direct-acting antiviral agents (DAAs) results in cure, or sustained viral response (SVR), in more than 90% of patients. However, there are subsets of patients who have persistent liver inflammation and fibrosis and develop hepatocellular carcinoma (HCC) despite achieving SVR. A possible reason for these phenomena may be the presence of virus particles in liver tissue but not blood, otherwise defined as occult infection.

OBJECTIVE.—

To describe liver histologic findings following successful DAA therapy, test HCV RNA by (liver) tissue polymerase chain reaction in treated cases, and identify predictive markers for HCC development in treated cases.

DESIGN.—

A total of 96 identified patients were divided into 4 groups, each differentiated by the presence or absence of SVR and HCC. Groups were compared for several clinicopathologic variables, including degree of inflammation and fibrosis, and the 'directionality' of fibrosis in cirrhotic livers using the novel progressive-indeterminate-regressive scoring system.

RESULTS.—

Overall, we found a significant decrease in inflammation in SVR patients. None of the patients showed regression of their cirrhosis following treatment. No evidence of occult HCV infection was seen in 40 livers tested, including 21 with HCC. The number of patients who developed HCC was similar in the SVR and non-SVR groups, and increased inflammation and fibrosis were associated with HCC development.

CONCLUSIONS.—

Following DAA-SVR there appears to be an overall decrease in inflammation, but the fibrosis tends to persist, at least in the short term (median follow-up of 20.2 months).

Screening for Hepatitis C Virus Infection in Adolescents and Adults: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force

IMPORTANCE

A 2013 review for the US Preventive Services Task Force (USPSTF) of hepatitis C virus (HCV) screening found interferon-based antiviral therapy associated with increased likelihood of sustained virologic response (SVR) and an association between achieving an SVR and improved clinical outcomes. New direct-acting antiviral (DAA) regimens are available.

OBJECTIVE

To update the 2013 review on HCV screening to inform the USPSTF.

DATA SOURCES

Ovid MEDLINE, the Cochrane Central Register of Controlled Trials, and the Cochrane Database of Systematic Reviews through February 2019, with surveillance through September 2019.

STUDY SELECTION

Randomized clinical trials (RCTs) and nonrandomized treatment studies of HCV screening and DAA therapy; cohort studies on screening, antiviral therapy, and the association between an SVR after antiviral therapy and clinical outcomes.

DATA EXTRACTION AND SYNTHESIS

One investigator abstracted data; a second checked accuracy. Two investigators independently rated study quality.

MAIN OUTCOMES AND MEASURES

Mortality, morbidity, quality of life, screening and treatment harms, and screening diagnostic yield.

RESULTS

Eight RCTs of DAA therapy vs placebo or an outdated antiviral regimen, 48 other treatment studies, and 33 cohort studies, with a total of 179 230 participants, were included. No study evaluated effects of HCV screening vs no screening. One new study since the 2013 review (n = 5917) found similar diagnostic yield of risk-based screening (sensitivity, 82%; number needed to screen to identify 1 HCV case, 15) and birth cohort screening (sensitivity, 76%; number needed to screen, 29), assuming perfect implementation. Ten open-label studies (n = 3292) reported small improvements in some quality-of-life and functional outcomes (eg, less than 3 points on the 0 to 100 36-Item Short Form Health Survey physical and mental component summary scales) after DAA treatment compared with before treatment. Two cohort studies (n = 24 686) found inconsistent associations of antiviral therapy vs no therapy with risk of hepatocellular carcinoma. Forty-nine treatment studies (n = 10 181) found DAA regimens associated with pooled SVR rates greater than 95% across genotypes, and low short-term rates of serious adverse events (1.9%) and withdrawal due to adverse events (0.4%). An SVR after antiviral therapy was associated with decreased adjusted risk of all-cause mortality (13 studies, n = 36 986; pooled hazard ratio [HR], 0.40 [95% CI, 0.28-0.56) and hepatocellular carcinoma (20 studies, n = 84 491; pooled HR, 0.29 [95% CI, 0.23 to 0.38]) vs no SVR.

CONCLUSIONS AND RELEVANCE

Direct evidence on the effects of HCV screening on clinical outcomes remains unavailable, but DAA regimens were associated with SVR rates greater than 5% and few short-term harms relative to older antiviral therapies. An SVR after antiviral therapy was associated with improved clinical outcomes compared with no SVR.

Cost-Effectiveness Analysis of Baseline Testing for Resistance-Associated Polymorphisms to Optimize Treatment Outcome in Genotype 1 Noncirrhotic Treatment-Naïve Patients With Chronic Hepatitis C Virus

OBJECTIVES

Direct-acting antivirals containing nonstructural protein 5A (NS5A) inhibitors administered over 8 to 12 weeks are effective in ∼95% of patients with hepatitis C virus. Nevertheless, patients resistant to NS5A inhibitors have lower cure rates over 8 weeks (<85%); for these patients, 12 weeks of treatment produces cure rates greater than 95%. We evaluated the lifetime cost-effectiveness of testing for NS5A resistance at baseline and optimizing treatment duration accordingly in genotype 1 noncirrhotic treatment-naïve patients from the perspective of the UK National Health Service.

METHODS

A decision-analytic model compared (1) standard 12-week treatment (no testing), (2) shortened 8-week treatment (no testing), and (3) baseline testing with 12-/8-week treatment for those with/without NS5A polymorphisms. Patients who failed first-line therapy were retreated for 12 weeks. Model inputs were derived from published studies. Costs, quality-adjusted life-years, and the probability of cost-effectiveness were calculated.

RESULTS

Baseline testing had an incremental net monetary benefit (INMB) of £11 838 versus standard 12 weeks of therapy (no testing) and low probability (31%) of being the most cost-effective, assuming £30 000 willingness to pay. Shortened 8 weeks of treatment (no testing) had an INMB of £12 294 and the highest probability (69%) of being most cost-effective. Scenario analyses showed baseline testing generally had the highest INMB and probability of being most cost-effective if first- and second-line drug prices were low (<£20k).

CONCLUSIONS

Optimizing treatment duration based on NS5A polymorphisms for genotype 1 noncirrhotic treatment-naive patients in the United Kingdom is not cost-effective if the drug costs are high; the strategy is generally most cost-effective when drug prices are low (<£20k).

Effects of Upadacitinib Coadministration on the Pharmacokinetics of Sensitive Cytochrome P450 Probe Substrates: A Study With the Modified Cooperstown 5+1 Cocktail

The aim of this study was to characterize the effects of upadacitinib, a Janus kinase 1 inhibitor, on in vivo activity of different cytochrome P450 (CYP) enzymes using a cocktail approach. Healthy subjects (n = 20) received single oral doses of the modified Cooperstown 5+1 cocktail drugs (midazolam [CYP3A], caffeine [CYP1A2], warfarin + vitamin K [CYP2C9], omeprazole [CYP2C19], and dextromethorphan [CYP2D6]) without upadacitinib and on day 11 (midazolam) or 12 (all other probes) of a 15-day regimen of upadacitinib 30 mg once daily (extended-release formulation). Serial blood samples and 12-hour urine samples were collected for assays of the probe substrates and select metabolites. The ratio (90%CI) of area under the plasma concentration-time curve from time 0 to infinity (AUCinf ) central values when the cocktail drugs were administered with upadacitinib relative to when administered alone were 0.74 (0.68-0.80) for midazolam, 1.22 (1.15-1.29) for caffeine, 1.11 (1.07-1.15) for S-warfarin, 1.07 (0.95-1.22) for dextromethorphan, and 0.82 (0.72-0.94) for omeprazole. The ratio (90%CI) was 1.09 (1.00-1.19) for 5-hydroxy-omeprazole to omeprazole AUCinf ratio and 1.17 (0.97-1.41) for dextromethorphan to dextrorphan 12-hour molar urinary ratio. Upadacitinib 30 mg once daily (a dose that is twice the optimal dose in rheumatoid arthritis based on phase 3 results) has a limited effect on CYP3A activity (26% decrease in exposure of midazolam, a sensitive CYP3A substrate) and no relevant effects on CYP1A2, CYP2C9, CYP2C19, or CYP2D6 activity in vivo. No clinically relevant changes in plasma exposures are expected for drugs that are substrates for the evaluated CYP enzymes when coadministered with upadacitinib.

High rate of acute kidney injury in patients with chronic kidney disease and hepatitis C virus genotype 4 treated with direct-acting antiviral agents

BACKGROUND

Direct-acting antivirals (DAAs) have significantly improved the efficacy and safety of treating chronic hepatitis C (CHC), but their effectiveness and safety among patients with chronic kidney disease (CKD) remains poorly understood. Sofosbuvir/daclatasvir regimen is supposed to be used for patients with creatinine clearance more than 30 mL/min, while ombitasvir/paritaprevir/ritonavir regimen is used for patients with creatinine clearance less than 30 mL/min.

AIM

The aim of the study was to assess the safety and efficacy of DAAs among patients with CKD.

METHODS

Eighteen CKD stage 2-3b patients received sofosbuvir for 3 months. In addition, 42 CKD stage-4 patients received ritonavir-boosted paritaprevir plus ombitasvir for 3 months. Finally, ribavirin was added for 30 of them.

RESULTS

The patients'age was 49.2 ± 12 years. Baseline serum creatinine was 3.76 ± 1.67 mg/dL. Fifty patients were HCV genotype 4. A 3-month sustained viral response was achieved in 56 patients and 49 patients achieved a 6-month viral response. There were 11 relapsers. Acute kidney injury (AKI) upon CKD (AKI/CKD) occurred in 28 patients, of which 20 needed hemodialysis. Fifteen/28 recovered from AKI, whereas 13 were maintained on hemodialysis. In multivariate analysis, there were only two independent risk factors for developing AKI/CKD, i.e., being cirrhotic as defined by baseline abdominal ultrasound findings [odds ratio 4.15 (1.33-12.97); p = 0.013] and having had as DAA therapy OMV/PTV/RTV [odds ratio 7.35 (1.84-29.35); p = 0.001].

CONCLUSION

Treatment of HCV among stage 2, 3a, and 3b patients was achieved safely with a sofosbuvir-based regimen. We recommend that stage-4 patients wait until starting hemodialysis or transplantation.

Interferon at the cellular, individual, and population level in hepatitis C virus infection: Its role in the interferon-free treatment era

The advent of powerful direct-acting antiviral agents (DAAs) has revolutionized the treatment of hepatitis C. DAAs cure nearly all patients with short duration, oral treatments. Significant efforts are now underway to optimize DAA-based treatments. We discuss the potential role of interferon in this optimization. Clinical studies present compelling evidence that DAAs perform better in treatment-naive individuals than in individuals who previously failed treatment with interferon, a surprising correlation because interferon and DAAs are thought to act independently. Recent mathematical models explore a mechanistic hypothesis underlying this correlation. The hypothesis invokes the action of interferon at the cellular, individual, and population levels. Strong interferon responses prevent the productive infection of cells, reduce viral replication, and impede the development of resistance to DAAs in infected individuals and improve cure rates elicited by DAAs in treated populations. The models develop descriptions of these processes, integrate them into a comprehensive framework, and capture clinical data quantitatively, providing a successful test of the hypothesis. Individuals with strong endogenous interferon responses thus present a promising subpopulation for reducing DAA treatment durations. This review discusses the conceptual advances made by the models, highlights the new insights they unravel, and examines their applicability to optimize DAA-based treatments.

A Cost-Effectiveness Analysis of Shortened Direct-Acting Antiviral Treatment in Genotype 1 Noncirrhotic Treatment-Naive Patients With Chronic Hepatitis C Virus

BACKGROUND

Direct-acting antivirals are successful in curing hepatitis C virus infection in more than 95% of patients treated for 12 weeks, but they are expensive. Shortened treatment durations, which may have lower cure rates, have been proposed to reduce costs.

OBJECTIVES

To evaluate the lifetime cost-effectiveness of different shortened treatment durations for genotype 1 noncirrhotic treatment-naive patients.

METHODS

Assuming a UK National Health Service perspective, we used a probabilistic decision tree and Markov model to compare 3 unstratified shortened treatment durations (8, 6, and 4 weeks) against a standard 12-week treatment duration. Patients failing shortened first-line treatment were re-treated with a 12-week treatment regimen. Parameter inputs were taken from published studies.

RESULTS

The 8-week treatment duration had an expected incremental net monetary benefit of £7737 (95% confidence interval £3242-£11 819) versus the standard 12-week treatment, per 1000 patients. The 6-week treatment had a positive incremental net monetary benefit, although some uncertainty was observed. The probability that the 8- and 6-week treatments were the most cost-effective was 56% and 25%, respectively, whereas that for the 4-week treatment was 17%. Results were generally robust to sensitivity analyses, including a threshold analysis that showed that the 8-week treatment was the most cost-effective at all drug prices lower than £40 000 per 12-week course.

CONCLUSIONS

Shortening treatments licensed for 12 weeks to 8 weeks is cost-effective in genotype 1 noncirrhotic treatment-naive patients. There was considerable uncertainty in the estimates for 6- and 4-week treatments, with some indication that the 6-week treatment may be cost-effective.

Clinical outcomes after the introduction of direct antiviral agents for patients infected with genotype 1b hepatitis C virus depending on the regimens: A multicenter study in Korea

BACKGROUND

A real-life study is essential outside clinical trials. The aim is to evaluate the clinical outcomes of direct acting agents (DAA) for patients with chronic hepatitis C (CHC) in real practice.

METHODS

We analyzed 590 consecutively enrolled patients with CHC-1b who received DAAs since 2015, when DAAs were introduced in Korea. The patients were checked for resistance-associated variants (RAV) against nonstructural protein 5A inhibitors and then daclatasvir/asunaprevir or sofosbuvir based regimens were chosen.

RESULTS

The frequency of patients with cirrhosis and prior hepatocellular carcinoma (HCC) was 29.2% and 4.7%, respectively. For the RAV test, 10% were positive and in 3.6% the result was "indeterminate." Overall, 518 patients were treated with a 24-week regimen of daclatasvir/asunaprevir, 72 patients (RAV positive 75%) were treated with 12 weeks regimen of ledipasvir/sofosbuvir or daclatasvir/sofosbuvir. The SVR12 was 94.0% in the daclatasvir/asunaprevir, 98.2% in the ledipasvir/sofosbuvir, and 100% in the daclatasvir/sofosbuvir group. A total of 93.3% of SVR12 in the RAV-"indeterminate" patients was not difference 95.0% in the RAV-negative patients. Up to 1 year, de novo HCC occurrence and recurrence developed in 2.6% and 17.8%, respectively. HCC was more frequent in cirrhotic patients than in noncirrhotic patients (P = 0.000). α Fetoprotein (AFP) level at the end of treatment was a predicting factor for de novo HCC.

CONCLUSIONS

Optimizing the choice of DAAs according to RAV test resulted in high SVR among CHC-1b Korean patients. This real practice multicenter cohort study suggests the importance of AFP and HCC surveillance in cirrhotic patients even after successful HCV therapy.

Ombitasvir/paritaprevir/ritonavir + dasabuvir +/- ribavirin in real world hepatitis C patients

BACKGROUND

The hepatitis C virus (HCV) NS5A inhibitor ABT-267 (ombitasvir, OBV), the HCV NS4/4A protease inhibitor ABT-450 (paritaprevir, PTV), the CYP3A inhibitor ritonavir (r) and the non-nucleoside NS5B polymerase inhibitor ABT-333 (dasabuvir, DSV) (OBV/PTV/r + DSV) with or without ribavirin (RBV) is a direct-acting antiviral regimen approved in the United States and other major countries for the treatment of HCV in genotype 1 (GT1) infected patients. Patients with HCV who are considered "hard-to-cure" have generally been excluded from registration trials due to rigorous study inclusion criteria, presence of comorbidities and previous treatment failures.

AIM

To investigate the efficacy of this regimen in HCV G1-infected patients historically excluded from clinical trials.

METHODS

Patients were ≥ 18 years old and chronically infected with HCV GT1 (GT1a, GT1b or GT1a/1b). Patients were treatment-naïve or previously failed a regimen including pegylated interferon/RBV +/- telaprevir, boceprevir, or simeprevir. One hundred patients were treated with the study drug regimen, which was administered for 12 or 24 wk +/- RBV according to GT1 subtype and presence/absence of cirrhosis. Patients were evaluated every 4 wk from treatment day 1 and at 4 and 12 wk after end-of-treatment.

RESULTS

Many of the patients studied had comorbidities (44.2% hypertensive, 33.7% obese, 20.2% cirrhotic) and 16% previously failed HCV treatment. Ninety-six patients completed study follow-up and 99% achieved 12-wk sustained virologic response. The majority (88.4%) of patients had undetectable HCV RNA by week 4. The most common adverse events were fatigue (12%), headache (10%), insomnia (9%) and diarrhea (8%); none led to treatment discontinuation. Physical and mental patient reported outcomes scores significantly improved after treatment. Almost all (98%) patients were treatment compliant.

CONCLUSION

In an all-comers HCV GT1 population, 12 or 24-wk of OBV/PTV/r + DSV +/- RBV is highly effective and tolerable and results in better mental and physical health following treatment.

Safety and efficacy of the combination simeprevir-sofosbuvir in HCV genotype 1- and 4-mono-infected patients from the French ANRS CO22 hepather cohort

BACKGROUND

Although real-life results of sofosbuvir/simeprevir have been extensively reported from the United States, data from other geographical areas are limited. In the French observational cohort, ANRS CO22 HEPATHER, 9432 patients were given the new oral antivirals from December 2013 to June 30, 2018. We report the results of sofosbuvir/simeprevir in genotypes 1- and 4-infected patients.

METHODS

Demographics and history of liver disease were collected at entry in the cohort. Clinical, adverse events, and virological data were collected throughout treatment and post-treatment follow-up. The choice of treatment duration or addition of ribavirin was left up to the physician.

RESULTS

Five hundred ninety-nine HCV (467 genotype 1 and 132 genotype 4) mono-infected, naïve for all oral-DAAs regimen patients were given sofosbuvir/simeprevir with (n = 63) or without ribavirin (n = 536) for 12 or 24 weeks; 56% had cirrhosis (4% decompensated) and 71% had prior treatment failure to interferon-based regimen. 7 patients (1.16%) were lost to follow-up. The overall SVR12 rate was 92.6%. The SVR12 was 90% in GT1a, 94.2% in GT1b and 91.6% in GT4 with no significant difference for genotype, treatment duration or ribavirin addition. Severity of liver disease was not associated with a lower SVR12 rate on multivariate analysis but was associated with a higher rate of severe side effects. Early treatment discontinuations were rare; no new safety signals were reported.

CONCLUSION

In this real life, observational, prospective cohort study, the 12-week sofosbuvir/simeprevir+/-ribavirin combination appears to be efficient and safe.

TRIAL REGISTRATION

Trial registration with ClinicalTrials.gov NCT01953458 .

Trends in hepatitis C treatment initiation among HIV/hepatitis C virus-coinfected men engaged in primary care in a multisite community health centre in Maryland: a retrospective cohort study

OBJECTIVES

Little is known about the cascade of hepatitis C care among HIV/hepatitis C virus (HCV)-coinfected patients in community-based clinics. Thus, we analysed our data from the interferon era to understand the barriers to HCV treatment, which may help improve getting patients into treatment in the direct-acting antivirals era.

DESIGN

Retrospective cohort study.

SETTING

Four HIV clinics of a multisite community health centre in the USA.

PARTICIPANTS

1935 HIV-infected men with >1 medical visit to the clinic between 2011 and 2013. Of them, 371 had chronic HCV and were included in the analysis for HCV care continuum during 2003-2014.

OUTCOME MEASURES

HCV treatment initiation was designated as the primary outcome for analysis. Multivariate logistic regression was performed to identify factors associated with HCV treatment initiation.

RESULTS

Among the 371 coinfected men, 57 (15%) initiated HCV treatment. Entering care before 2008 (adjusted OR [aOR, 3.89; 95% CI, 1.95 to 7.78), higher educational attainment (aOR, 3.20; 95% CI, 1.59 to 6.44), HCV genotype 1 versus non-1 (aOR, 0.21; 95% CI, 0.07 to 0.65) and HIV suppression (aOR, 2.13; 95% CI, 1.12 to 4.06) independently predicted treatment initiation. Stratification by entering care before or after 2008 demonstrated that higher educational attainment was the only factor independently associated with treatment uptake in both periods (aOR, 2.79; 95% CI, 1.13 to 6.88 and aOR, 4.10; 95% CI, 1.34 to 12.50, pre- and post-2008, respectively). Additional associated factors in those entering before 2008 included HCV genotype 1 versus non-1 (aOR, 0.09; 95% CI, 0.01 to 0.54) and HIV suppression (aOR, 2.35; 95% CI, 1.04 to 5.33).

CONCLUSIONS

Some traditional barriers predicted HCV treatment initiation in those in care before 2008; however, the patients' level of educational attainment remained an important factor even towards the end of the interferon era. Further studies will need to determine whether educational attainment persists as an important determinant for initiating direct-acting antiviral therapies.

Gastric-acid-mediated drug-drug interactions with direct-acting antiviral medications for hepatitis C virus infection: clinical relevance and mitigation strategies

Drug-drug interactions (DDIs) between direct-acting antiviral (DAA) medications and acid-reducing agents mediated by gastric acid represent an important issue in drug development and treatment, which could lead to impaired bioavailability and subtherapeutic plasma concentrations of DAA drugs and subsequently compromised treatment outcomes. However, identification of clinically relevant drug interactions associated with elevated gastric pH is not well characterized. Here, we present the first comprehensive analysis of the gastric-acid-mediated drug interactions with all novel DAA medications by analyzing and revisiting in vitro data, prospective DDI trials and retrospective assessments based upon Phase II and III studies, aiming toward an in-depth understanding of the clinical implications and mitigation strategies to circumvent such interactions.

Creating demand for long-acting formulations for the treatment and prevention of HIV, tuberculosis, and viral hepatitis

PURPOSE OF REVIEW

Long-acting parenteral drug delivery is an established and widely accepted solution to the problem of poor adherence when daily oral medications are used to treat or prevent chronic medical conditions. Poor adherence to oral formulations remains a major barrier to successfully treating or preventing HIV, tuberculosis (TB), and viral hepatitis. The uptake of long-acting formulations developed for these infections is uncertain, despite their promise. This review addresses the current state of development of long-acting and extended-release approaches to HIV, TB, and viral hepatitis in the context of creating market demand for such products.

RECENT FINDINGS

Two nanoformulated long-acting injectable antiretroviral compounds, cabotegravir and rilpivirine, recently completed Phase 2 clinical trials demonstrating safety, tolerability, and antiretroviral activity, and should be available in high income countries following completion of ongoing Phase 3 trials. Long-acting polymer implants of the antiretroviral nucleosides tenofovir alafenamide and 4'-ethynyl-2-fluoro-2'-deoxyadenosine are being tested in animals and should soon enter human studies; tenofovir alafenamide also has activity against hepatitis B virus. Long-acting versions of several broadly neutralizing monoclonal antibodies are in advanced clinical trials for HIV prevention and treatment. Long-acting formulations for TB are in preclinical development. There is no evidence that comparable formulations for viral hepatitis are being developed at present.

SUMMARY

Long-acting and extended release formulations are promising approaches to the treatment and prevention of common infectious diseases, but their availability is limited at this time. These products hold great promise for the global control of important human infections. Based on experience with other diseases, it is likely that their use will become more widespread if they are cost competitive with generic oral formulations.

Overview of Direct-Acting Antiviral Drugs and Drug Resistance of Hepatitis C Virus

The advent of direct-acting antivirals (DAAs) has brought about a sudden renaissance in the treatment of chronic hepatitis C virus (HCV) infection with SVR rates now routinely >90%. However, due to the error-prone nature of the HCV RNA polymerase, resistance-associated substitutions (RASs) to DAAs may be present at baseline and can result in a significant effect on treatment outcomes and hamper the achievement of sustained virologic response. By further understanding the patterns and nature of these RASs, it is anticipated that the incidence of treatment failure will continue to decrease in frequency with the development of drug regimens with increasing potency, barrier to resistance, and genotypic efficacy. This review summarizes our current knowledge of RASs associated with HCV infection as well as the clinical effect of RASs on treatment with currently available DAA regimens.

Use of Ribavirin for Hepatitis C Treatment in the Modern Direct-acting Antiviral Era

Ribavirin, once a staple of hepatitis C treatment, has significant drawbacks, including treatment-limiting side effects, the requirement for intensive laboratory monitoring, the need for frequent dose adjustments, and teratogenicity. These factors make it difficult to escalate ribavirin-based HCV treatment to most infected patients globally. Most studies have shown comparable response rates between ribavirin-inclusive and ribavirin-sparing regimens in uncomplicated patient populations. However, ribavirin is still used in the management of patients who have failed previous therapy as well as those with decompensated liver disease. In this review, we explore the evidence supporting the use of ribavirin in the current climate of hepatitis C treatment with oral combination direct-acting antiviral agents.

Minor contribution of CYP3A5 to the metabolism of hepatitis C protease inhibitor paritaprevir in vitro

Paritaprevir (PTV) is a non-structural protein 3/4A protease inhibitor developed for the treatment of hepatitis C disease as a fixed dose combination of ombitasvir (OBV) and ritonavir (RTV) with or without dasabuvir. The aim of this study was to evaluate the effects of cytochrome P450 (CYP) 3A5 on in vitro PTV metabolism using human recombinant CYP3A4, CYP3A5 (rCYP3A4, rCYP3A5) and human liver microsomes (HLMs) genotyped as either CYP3A5*1/*1, CYP3A5*1/*3 or CYP3A5*3/*3. The intrinsic clearance (CL_int, V_max/K_m) for the production of a metabolite from PTV in rCYP3A4 was 1.5 times higher than that in rCYP3A5. The PTV metabolism in CYP3A5*1/*1 and CYP3A5*1/*3 HLMs expressing CYP3A5 was comparable to that in CYP3A5*3/*3 HLMs, which lack CYP3A5. CYP3A4 expression level was significantly correlated with PTV disappearance rate and metabolite formation. In contrast, there was no such correlation found for CYP3A5 expression level. This study represents that the major CYP isoform involved in PTV metabolism is CYP3A4, with CYP3A5 having a minor role in PTV metabolism. The findings of the present study may provide foundational information on PTV metabolism, and may further support dosing practices in HCV-infected patients prescribed PTV-based therapy.

Real-world outcomes of unrestricted direct-acting antiviral treatment for hepatitis C in Australia: The South Australian statewide experience

In March 2016, the Australian government offered unrestricted access to direct-acting antiviral (DAA) therapy for chronic hepatitis C virus (HCV) to the entire population. This included prescription by any medical practitioner in consultation with specialists until sufficient experience was attained. We sought to determine the outcomes and experience over the first twelve months for the entire state of South Australia. We performed a prospective, observational study following outcomes of all treatments associated with the state's four main tertiary centres. A total of 1909 subjects initiating DAA therapy were included, representing an estimated 90% of all treatments in the state. Overall, SVR12 was 80.4% in all subjects intended for treatment and 95.7% in those completing treatment and follow-up. 14.2% were lost to follow-up (LTFU) and did not complete SVR12 testing. LTFU was independently associated with community treatment via remote consultation (OR 1.50, 95% CI 1.04-2.18, P = .03), prison-based treatment (OR 2.02, 95% CI 1.08-3.79, P = .03) and younger age (OR 0.98, 95% CI 0.97-0.99, P = .05). Of the 1534 subjects completing treatment and follow-up, decreased likelihood of SVR12 was associated with genotype 2 (OR 0.23, 95% CI 0.07-0.74, P = .01) and genotype 3 (OR 0.23, 95% CI 0.12-0.43, P ≤ .01). A significant decrease in treatment initiation was observed over the twelve-month period in conjunction with a shift from hospital to community-based treatment. Our findings support the high responses observed in clinical trials; however, a significant gap exists in SVR12 in our real-world cohort due to LTFU. A declining treatment initiation rate and shift to community-based treatment highlight the need to explore additional strategies to identify, treat and follow-up remaining patients in order to achieve elimination targets.

Development and clinical validation of the Genedrive point-of-care test for qualitative detection of hepatitis C virus

OBJECTIVE

Recently approved direct acting antivirals provide transformative therapies for chronic hepatitis C virus (HCV) infection. The major clinical challenge remains to identify the undiagnosed patients worldwide, many of whom live in low-income and middle-income countries, where access to nucleic acid testing remains limited. The aim of this study was to develop and validate a point-of-care (PoC) assay for the qualitative detection of HCV RNA.

DESIGN

We developed a PoC assay for the qualitative detection of HCV RNA on the PCR Genedrive instrument. We validated the Genedrive HCV assay through a case-control study comparing results with those obtained with the Abbott RealTime HCV test.

RESULTS

The PoC assay identified all major HCV genotypes, with a limit of detection of 2362 IU/mL (95% CI 1966 to 2788). Using 422 patients chronically infected with HCV and 503 controls negative for anti-HCV and HCV RNA, the Genedrive HCV assay showed 98.6% sensitivity (95% CI 96.9% to 99.5%) and 100% specificity (95% CI 99.3% to 100%) to detect HCV. In addition, melting peak ratiometric analysis demonstrated proof-of-principle for semiquantification of HCV. The test was further validated in a real clinical setting in a resource-limited country.

CONCLUSION

We report a rapid, simple, portable and accurate PoC molecular test for HCV, with sensitivity and specificity that fulfils the recent FIND/WHO Target Product Profile for HCV decentralised testing in low-income and middle-income countries. This Genedrive HCV assay may positively impact the continuum of HCV care from screening to cure by supporting real-time treatment decisions.

TRIAL REGISTRATION NUMBER

NCT02992184 .

Using telehealth to improve access to hepatitis C treatment in the direct-acting antiviral therapy era

Introduction

One-third of the Australian population lives outside major cities and this group has worse health outcomes. Telehealth is becoming an accepted way to improve patient access to specialist healthcare. Over 200,000 Australian’s have hepatitis C virus (HCV) and new treatments are very effective and well tolerated. We aim to demonstrate that HCV treatment utilising telehealth support for care delivery has cure rates similar to onsite care in clinical trials. We also report length of consultation and calculate reductions in travel and carbon output.

Methods

Patient demographic, clinical, and treatment outcome data were collected prospectively from hospital software and analysed retrospectively. This was an audit of all patients treated for HCV in one year from a single tertiary hospital that included telehealth in their care delivery.

Results

Sustained virological response was achieved in 51/52 (98%) patients with completed treatment courses, and 51/58 (88%) of those who had a planned telehealth consultation as part of their management. A median of 634 km of patient travel was saved per telehealth consultation.

Discussion

We found that a telehealth-supported outreach programme for patients in regional Australia with HCV produced similar outcomes to clinical trials. There was a considerable saving in time and cost for the patients and significant environmental benefit through the reduction in carbon footprint associated with travel to distant specialist health services. We conclude that telehealth facilitated outreach is a feasible and effective way to access HCV treatment and cure in regional Australia.

Early development of de novo hepatocellular carcinoma after direct-acting agent therapy: Comparison with pegylated interferon-based therapy in chronic hepatitis C patients

Patients with chronic hepatitis C who achieve a sustained viral response after pegylated interferon therapy have a reduced risk of hepatocellular carcinoma, but the risk after treatment with direct-acting antivirals is unclear. We compared the rates of early development of hepatocellular carcinoma after direct-acting antivirals and after pegylated interferon therapy. We retrospectively analysed 785 patients with chronic hepatitis C who had no history of hepatocellular carcinoma (211 treated with pegylated interferon, 574 with direct-acting antivirals) and were followed up for at least 24 weeks after antiviral treatment. De novo hepatocellular carcinoma developed in 6 of 574 patients receiving direct-acting antivirals and in 1 of 211 patients receiving pegylated interferon. The cumulative incidence of early hepatocellular carcinoma development did not differ between the treatment groups either for the whole cohort (1.05% vs 0.47%, P = .298) or for those patients with Child-Pugh Class A cirrhosis (3.73% vs 2.94%, P = .827). Multivariate analysis indicated that alpha-fetoprotein level >9.5 ng/mL at the time of end-of-treatment response was the only independent risk factor for early development of hepatocellular carcinoma in all patients (P < .0001, hazard ratio 176.174, 95% confidence interval 10.768-2882.473) and in patients treated with direct-acting agents (P < .0001, hazard ratio 128.402, 95% confidence interval 8.417-1958.680). In conclusion, the rate of early development of hepatocellular carcinoma did not differ between patients treated with pegylated interferon and those treated with direct-acting antivirals and was associated with the serum alpha-fetoprotein level at the time of end-of-treatment response.

Hepatitis C virus genotype 3: clinical features, current and emerging viral inhibitors, future challenges

Hepatitis C virus (HCV) represents a global burden on healthcare that affects over 150 million people worldwide. In the past, HCV genotype 3 was considered difficult to treat relative to other genotypes. Genotype 3 has been associated with a higher rate of complications, including fatty liver disease, fibrosis, hepatocellular carcinoma and mortality. However, with the advent of first- and second-generation direct-acting antivirals, genotype 3 can be treated effectively. Additionally, these new drugs are well tolerated by patients and have significantly fewer side effects compared to ribavirin and interferon-based regimens. However, while great strides have been made in overcoming biological barriers, our next challenge lies in overcoming economic and financial obstacles if we are to eradicate HCV genotype 3. Herein, we review the clinical features associated with HCV genotype 3, current and emerging treatment regimens, and challenges associated with treatment.

Clinical Pharmacokinetics of Paritaprevir

Paritaprevir is a potent hepatitis C virus (HCV) nonstructural (NS) protein 3/4A protease inhibitor that is used in combination with other direct-acting antivirals (DAAs) for the treatment of chronic HCV infection. Paritaprevir is primarily metabolized by cytochrome P450 (CYP) 3A4 and is administered with a low dose of ritonavir to achieve drug concentrations suitable for once-daily dosing. Coadministration of paritaprevir with ritonavir increases the half-life of single-dose paritaprevir from approximately 3 h to 5-8 h, doubles the time to maximum plasma concentration (T _max) from 2.3 to 4.7 h, and increases exposures 30-fold for maximum observed plasma concentration (C _max), 50-fold for area under the plasma concentration-time curve (AUC), and >300-fold for trough concentration (C ₂₄). Paritaprevir displays highly variable, nonlinear pharmacokinetics, with C _max and AUC increasing in a greater than dose proportional manner when administered with or without ritonavir. In the presence of ritonavir, paritaprevir is excreted mostly unchanged in feces via biliary excretion. Paritaprevir exposures are higher in Japanese subjects compared with Caucasian subjects; however, no dose adjustment is needed for Japanese patients as the higher exposures are safe and well tolerated. The pharmacokinetic characteristics of paritaprevir are similar between healthy subjects and HCV-infected patients, and are not appreciably altered by mild or moderate hepatic impairment or mild, moderate, or severe renal impairment, including those on dialysis. Paritaprevir exposures are increased in patients with severe hepatic impairment. Although the presence of a low dose of ritonavir in paritaprevir-containing regimens increases the likelihood of drug-drug interactions, results from several drug interaction studies demonstrated that paritaprevir-containing regimens can be coadministered with many comedications that are commonly prescribed in HCV-infected patients.

Clinical Pharmacokinetics of Ombitasvir

Ombitasvir is a potent, nonstructural protein 5A inhibitor of the hepatitis C virus (HCV) that is used in combination with other direct-acting antivirals for the treatment of chronic HCV infection. Ombitasvir is predominantly metabolized by amide hydrolysis followed by oxidative metabolism and is a substrate of P-glycoprotein. Ombitasvir displays linear pharmacokinetics with minimal accumulation and is eliminated via metabolism and biliary excretion. A negligible amount of unchanged drug is excreted in urine. Exposures are comparable across Chinese, Japanese, and non-Asian subjects. The pharmacokinetic characteristics of ombitasvir are similar in healthy subjects and HCV-infected patients, and are not appreciably altered by hepatic or renal impairment. Results from several drug interaction studies demonstrated that ombitasvir has a low potential for drug interactions.

Poor response to direct-acting antiviral therapy in HCV-infected elderly population: a real-life cohort study based on GeneXpert® technology

Aim: This study aimed to determine the efficacy of direct-acting antiviral drugs in different ethnicities and elderly population of Pakistan. Methods: We used GeneXpert® technology to quantify HCV RNA and evaluated treatment response in different cohorts that included HCV patients classified on the basis of their age-group and ethnicity. Results: The findings of our study suggest that 76% of nonresponder patients were older than 55 years of age which shows that age is the predictor of treatment outcome of direct-acting antiviral drugs. In addition to this, no differences were observed in overall efficacy by ethnicity. Conclusion: Treatment-regimen sofosbuvir+ribavirin has a limited effect on older patients; therefore, practitioners and healthcare professionals need to reconsider treatment options for elderly populations.

Treatment of Chronic Hepatitis C in Patients Receiving Opioid Agonist Therapy: A Review of Best Practice

Injection drug use is the most common transmission route for hepatitis C. High rates of infection are observed among individuals on opioid agonist therapy. Although people who inject drugs carry the highest burden, few have initiated treatment. We present a comprehensive review of the evidence on the efficacy of HCV medications, drug-drug interactions, and barriers to and models of care. Studies have demonstrated comparable efficacy for individuals who are on opioid agonist therapy compared with those who are not. We propose that a strategy of treatment and cure-as-prevention is imperative in this population to curb the hepatitis C epidemic.

Signal detection on a patient cohort: A disproportionality analysis of the ANRS CO22 HEPATHER cohort to identify associations between direct acting antivirals and adverse events in patients with hepatitis C virus chronic infection

PURPOSE

Our aim was to explore a signal detection method for early identification of potential adverse drug reactions (ADRs) in a patient cohort.

METHODS

ANRS CO22 HEPATHER is a French multicentre prospective observational cohort started in 2012. The cohort includes patients with chronic hepatitis C virus (HCV) infection with reports of all adverse events (AEs) occurring in patients exposed to HCV drugs. We applied a disproportionality method, which calculated a measure of association, the Bayesian information component (IC), for each drug-AE pair. Information components were continuously updated and a positive drug-AE association was detected when the lower limit of an IC 95% credible interval (95% CI) exceeded 0. We illustrate how the method could result in timely detection of photosensitivity reaction with simeprevir use.

RESULTS

By August 28, 2016, 6600 patients with HCV infection had been treated or were undergoing current HCV treatment, and 3464 experienced at least one AE for a total of 12 720 reported AEs. We detected 52 positive drug-AE associations, including 44 that were known ADRs based on the summary of product characteristics. The association between simeprevir and photosensitivity reaction was detected on June 4, 2014. At this date, 68 patients had received simeprevir and 6 photosensitivity reaction (4 during simeprevir treatment) had been reported for an estimated IC of 1.90, 95% CI, 0.20-3.61.

CONCLUSIONS

The disproportionality method can help with early detection of potential ADRs in patient cohorts. Detected associations need to be confirmed by a review of clinical data.

Revisiting policy on chronic HCV treatment under the Thai Universal Health Coverage: An economic evaluation and budget impact analysis

Thailand is encountering challenges to introduce the high-cost sofosbuvir for chronic hepatitis C treatment as part of the Universal Health Care's benefit package. This study was conducted in respond to policy demand from the Thai government to assess the value for money and budget impact of introducing sofosbuvir-based regimens in the tax-based health insurance scheme. The Markov model was constructed to assess costs and benefits of the four treatment options that include: (i) current practice-peginterferon alfa (PEG) and ribavirin (RBV) for 24 weeks in genotype 3 and 48 weeks for other genotypes; (ii) Sofosbuvir plus peginterferon alfa and ribavirin (SOF+PEG-RBV) for 12 weeks; (iii) Sofosbuvir and daclatasvir (SOF+DCV) for 12 weeks; (iv) Sofosbuvir and ledipasvir (SOF+LDV) for 12 weeks for non-3 genotypes and SOF+PEG-RBV for 12 weeks for genotype 3 infection. Given that policy options (ii) and (iii) are for pan-genotypic infection, the cost of genotype testing was applied only for policy options (i) and (iv). Results reveal that all sofosbuvir-based regimens had greater quality adjusted life years (QALY) gains compared with the current treatment, therefore associated with lower lifetime costs and more favourable health outcomes. Additionally, among the three regimens of sofosbuvir, SOF+PEG-RBV for genotype 3 and SOF+LDV for non-3 genotype are the most cost-effective treatment option with the threshold of 160,000 THB per QALY gained. The results of this study had been used in policy discussion which resulted in the recent inclusion of SOF+PEG-RBV for genotype 3 and SOF+LDV for non-3 genotype in the Thailand's benefit package.

Exposure-Safety Response Relationship for Ombitasvir, Paritaprevir/Ritonavir, Dasabuvir, and Ribavirin in Patients with Chronic Hepatitis C Virus Genotype 1 Infection: Analysis of Data from Five Phase II and Six Phase III Studies

BACKGROUND AND OBJECTIVES

All-oral direct-acting antiviral regimens that include combinations of ombitasvir, paritaprevir, ritonavir, and dasabuvir with or without ribavirin were evaluated in hepatitis C virus-infected patients in phase II/III clinical studies. The objective of these analyses was to quantify the relationship between exposures of the components of the regimen and laboratory values and to determine covariates that could influence the relationship.

METHODS

Exposure-safety response relationships between individual components of the direct-acting antiviral regimens and clinically important laboratory values were explored using data from 2998 patients from 11 phase II/III clinical studies. Multivariate logistic regression analyses were used to identify significant relationships between predictor variables and response variables.

RESULTS

No statistically significant associations were observed between ombitasvir, dasabuvir, or ritonavir exposures and maximum post-baseline alanine aminotransferase (ALT) or total bilirubin grade or minimum hemoglobin grade. A two-fold increase in paritaprevir exposure from therapeutic exposure was predicted to increase the probability of experiencing a grade 3 or higher increase in ALT by 0.5% and bilirubin by 1.1%. In the phase II/III clinical studies, ALT and bilirubin increases were reversible with continued dosing or after treatment cessation. Other correlates with adverse events of clinical importance included concomitant ribavirin treatment, sex, race, and presence of cirrhosis, consistent with previous observations.

CONCLUSIONS

Exposure-response analyses from phase II/III studies with the combination direct-acting antiviral regimen indicated no statistically significant relationships with ombitasvir, dasabuvir, or ritonavir exposure, but a statistically significant association was observed between paritaprevir exposure and the probability of experiencing a grade 3 or higher increase in ALT or bilirubin.

Efficacy of Interferon-Free Therapies for Chronic Hepatitis C: A Systematic Review of All Randomized Clinical Trials

BACKGROUND AND OBJECTIVES

Second-generation direct-acting antivirals (DAAs) have recently arisen as more effective and safer treatments for chronic hepatitis C. These drugs can be combined into treatments without interferon (IFN), and are therefore called IFN-free therapies.

OBJECTIVE

The objective of this study systematic review was to evaluate the efficacy of IFN-free therapies for the treatment of chronic hepatitis C, and thus increase the clinical evidence for these therapies.

METHODS

A systematic review was conducted in accordance with Cochrane Collaboration recommendations. A search was performed in six different electronic databases using 'clinical trials', 'hepatitis C' and 'interferon-free' as the main descriptors, and studies that conformed to the inclusion criteria had their data extracted, including study information, baseline characteristics, and efficacy outcomes (sustained virologic response, rapid virologic response, and virologic failure).

RESULTS

Sixty-four randomized clinical trials including 15 different therapies were included in a total of 15,731 patients infected with the hepatitis C virus, mostly with genotype 1, and mainly treated for 12 or 24 weeks. The sustained virologic response rate after 12 weeks of treatment was approximately 89%, while the virologic failure rate was below 5%.

CONCLUSIONS

Second-generation DAAs presented several advantages: virologic response values higher than the average achieved by previous IFN-based therapies, reduced treatment duration, and the possibility of different combinations of therapies to meet patient needs. Thus, IFN-free therapies appear to be valuable alternatives for the treatment of chronic hepatitis C.

Primer on Hepatitis C Virus Resistance to Direct-Acting Antiviral Treatment: A Practical Approach for the Treating Physician

Treatment of hepatitis C virus has been vastly transformed by the arrival of all-oral, interferon-free, direct-acting antiviral regimens. Despite the high rate of success with these agents, a small portion of treated patients fail therapy and the emergence of viral resistance is the most common cause of treatment failure. Given the error-prone hepatitis C virus polymerase, baseline resistance-associated substitutions (RASs) may be present before direct-acting antiviral exposure. Clinicians need to understand the role of baseline RAS testing and the settings and manner in which the treatment regimens need to be customized based on the presence of RASs.

Dose- and Formulation-Dependent Non-Linear Pharmacokinetic Model of Paritaprevir, a Protease Inhibitor for the Treatment of Hepatitis C Virus Infection: Combined Analysis from 12 Phase I Studies

BACKGROUND AND OBJECTIVES

Paritaprevir is a direct-acting antiviral agent that is a component of approved multidrug regimens used in the treatment of hepatitis C virus (HCV) infection. A population pharmacokinetic model for paritaprevir was developed using data from formulation, bioavailability, and drug-drug interaction studies that evaluated the pharmacokinetics of paritaprevir (coadministered with ritonavir to enhance exposure) with or without ombitasvir and/or dasabuvir at different paritaprevir dose levels.

METHODS

A non-linear mixed-effects modeling approach was applied to data from 12 phase I, single- and multiple-dose studies that enrolled a total of 369 healthy volunteers. Age, sex, race, ethnicity, body weight, body surface area, body mass index, and baseline creatinine clearance were evaluated as covariates during model development. In addition, the influences of dose, formulation, and concomitant medications (e.g. ombitasvir and dasabuvir) on paritaprevir bioavailability were included in the model.

RESULTS

A two-compartment model with first-order absorption and elimination optimally described paritaprevir plasma concentration-time data. Paritaprevir bioavailability was formulation- and dose-dependent, and increased supraproportionally. The accumulation of paritaprevir was 1.57-fold on repeated dosing compared with the first dose. Coadministration of dasabuvir increased paritaprevir bioavailability by 59 %; however, ombitasvir coadministration did not affect the pharmacokinetic profile of paritaprevir. No subject-specific covariate influenced the paritaprevir pharmacokinetics. The pharmacokinetic model was robust in bootstrap evaluations and was consistent with observed data based on diagnostic goodness-of-fit plots and visual predictive checks.

CONCLUSION

The complex pharmacokinetics of paritaprevir were well described by the model, which can be used as a basis for clinical trial dosing and further evaluations in patients with HCV.

Drug-Drug Interactions Between the Anti-Hepatitis C Virus 3D Regimen of Ombitasvir, Paritaprevir/Ritonavir, and Dasabuvir and Eight Commonly Used Medications in Healthy Volunteers

Background and Aims

The three direct-acting antiviral regimen of ombitasvir/paritaprevir/ritonavir and dasabuvir (3D regimen) is approved for treatment of hepatitis C virus (HCV) genotype 1 infection. Drug–drug interaction (DDI) studies of the 3D regimen and commonly used medications were conducted in healthy volunteers to provide information on coadministering these medications with or without dose adjustments.

Methods

Three phase I studies evaluated DDIs between the 3D regimen (ombitasvir/paritaprevir/ritonavir 25/150/100 mg once daily + dasabuvir 250 mg twice daily) and hydrocodone bitartrate/acetaminophen (5/300 mg), metformin hydrochloride (500 mg), diazepam (2 mg), cyclobenzaprine hydrochloride (5 mg), carisoprodol (250 mg), or sulfamethoxazole/trimethoprim (SMZ/TMP) (800/160 mg twice daily), all administered orally. DDI magnitude was determined using geometric mean ratios and 90 % confidence intervals for the maximum plasma concentration (C_max) and area under the plasma concentration–time curve (AUC).

Results

Changes in exposures (C_max and AUC geometric mean ratios) of acetaminophen, metformin, sulfamethoxazole, trimethoprim, and diazepam were ≤25 % upon coadministration with the 3D regimen. The C_max and AUC of nordiazepam, an active metabolite of diazepam, increased by 10 % and decreased by 44 %, respectively. Exposures of cyclobenzaprine and carisoprodol decreased by ≤40 and ≤46 %, respectively, whereas exposures of hydrocodone increased up to 90 %. Ombitasvir, paritaprevir, ritonavir, and dasabuvir exposures changed by ≤25 %, except for a 37 % decrease in paritaprevir C_max with metformin and a 33 % increase in dasabuvir AUC with SMZ/TMP.

Conclusions

Acetaminophen, metformin, sulfamethoxazole, and trimethoprim can be coadministered with the 3D regimen without dose adjustment. Higher doses may be needed for diazepam, cyclobenzaprine, and carisoprodol based on clinical monitoring. A 50 % lower dose and/or clinical monitoring should be considered for hydrocodone. No dose adjustment is necessary for the 3D regimen.

Safety and Efficacy of Treatment of Hepatitis C in Kidney Transplant Recipients With Directly Acting Antiviral Agents

BACKGROUND

With the development of all oral, interferon-free directly acting antiviral (DAA) medications, treatment of hepatitis C virus (HCV) infection in renal transplant recipients is possible, but limited data exists on its safety and efficacy.

METHODS

We performed a retrospective cohort analysis of patients transplanted at our center with HCV who have been started on DAAs. Primary endpoints included sustained virologic response as defined as negative viral load at 12 weeks postcompletion of therapy and allograft function.

RESULTS

A total of 31 patients met inclusion criteria. The most commonly used regimen was sofosbuvir and ledipasvir (n = 21). Of the treated patients, 100% had undetectable viral load at the completion of therapy. Of the 31 patients treated, 30 (97%) achieved sustained virologic response. Both graft and patient survivals at most recent follow-up was 100%. There was no significant change in glomerular filtration rate (GFR) before or after therapy (64.2 ± 16.5 mL/min per body surface area before vs. 58.9 ± 17.5 mL/min per body surface area after therapy; P = 0.22); however, 3 patients now have GFR less than 20. A total of 6 (19.3%) of 31 patients had worsening proteinuria during or shortly after therapy. Patients with more than 500 mg/g of proteinuria at the start of treatment were significantly more likely to develop worsening proteinuria than those with less than 500 mg/g of proteinuria at the start of therapy (P < 0.001). Retrospective review of 20 untreated HCV patients did not demonstrate worsening allograft function and proteinuria during a median follow-up time of 1386 days (range, 332-6254).

CONCLUSIONS

Our preliminary data demonstrate that DAAs can be used safely and effectively in patients after kidney transplantation. Patients with proteinuria or lower GFR should be monitored more closely.

Role of ribavirin in interferon-free therapy for the treatment of hepatitisC virus

Interferon-free regimens achieve sustained virologic response (SVR) rates of over 90%, have generally well-tolerated adverse effects and involve 12-week treatment durations for most patients with chronic hepatitis C, including naive or previously treated patients and patients with or without cirrhosis. However, some of the treatment options recommended by the guidelines require the addition of ribavirin (RBV) or extend the duration of treatment to increase efficacy. The use of RBV is a useful tool in those difficult-to-cure patients such as patients with decompensated or genotype-3-infected cirrhosis and those who have not achieved SVR after treatment with direct-acting antivirals (DAA). Overall, adding RBV to the different combinations causes adverse effects related to a decrease in haemoglobin and involves inconveniences such as its dosage, which requires patients to take several tablets twice daily. However, severe anaemia is rare and easily manageable with a dose reduction. In addition, RBV is teratogenic. In practice, because RBV is inexpensive and well tolerated when combined with an interferon-free regimen, it continues to be a useful tool to optimise the results of some HCV treatment regimens. RBV-free regimens eliminate RBV-related adverse effects related, resulting in better tolerability, improving patient adherence and quality of life and reducing the cost of treatment.

Population Pharmacokinetics of Paritaprevir, Ombitasvir, and Ritonavir in Japanese Patients with Hepatitis C Virus Genotype 1b Infection

BACKGROUND AND OBJECTIVE

Hepatitis C virus (HCV) infection is of considerable clinical concern in Japan. We modeled the population pharmacokinetics of an oral interferon-free, direct-acting antiviral agent (DAA) regimen (i.e., the 2D regimen) recently approved for the treatment of chronic HCV genotype 1 infection as a new option for affected Japanese patients.

METHODS

Using data from a phase III clinical trial (GIFT-I) that enrolled Japanese patients with HCV genotype 1b infection, population pharmacokinetic models were developed for the drugs that comprise the 2D regimen: paritaprevir, ombitasvir, and ritonavir. Demographic and clinical covariates with potential to influence 2D pharmacokinetics were evaluated for their effects on drug exposures. Proposed models were assessed using goodness-of-fit plots, visual predictive checks, and bootstrap evaluations.

RESULTS

One-compartment models with first-order absorption and elimination adequately described the population pharmacokinetics of paritaprevir, ombitasvir, and ritonavir. On average, patients with cirrhosis had approximately 95-145 % higher, 19-24 % lower, and 58-68 % higher exposures of paritaprevir, ombitasvir, and ritonavir, respectively. Female patients had 58-81 % higher ombitasvir exposures, whereas patients with mild renal impairment (creatinine clearance 75 mL/min) had 9-14 % higher ombitasvir exposures than did patients with normal renal function (creatinine clearance 105 mL/min). The DAA exposure values were comparable between responders and non-responders.

CONCLUSION

Population pharmacokinetic modeling did not reveal any patient-related or clinical parameters that would require dose adjustment of the 2D regimen when used for the treatment of HCV genotype 1b infection in Japanese patients.

Application of Exposure-Response Analyses to Establish the Pharmacodynamic Similarity of a Once-Daily Regimen to an Approved Twice-Daily Dosing Regimen for the Treatment of HCV Infection

The triple direct-acting antiviral (3-DAA) regimen (two co-formulated tablets of ombitasvir/paritaprevir/ritonavir once daily and one tablet of dasabuvir twice daily) for patients with hepatitis C virus (HCV) genotype 1 infection has been reformulated for once-daily administration containing all three active DAAs (3QD regimen). Two bioequivalence studies compared the 3-DAA and 3QD regimens. In study 1, fed, single-, and multiple-dose crossover comparisons revealed exposures for drug components that were slightly outside the bioequivalence criteria, i.e., 21 to 29% lower dasabuvir C _trough, paritaprevir C _max, and ritonavir C _max. In study 2, fed and fasted single-dose crossover comparisons demonstrated a large impact of food on exposures, confirming the product's labeling requirement for administration only with food, and revealed a lack of bioequivalence under fasting conditions. Exposure-response analyses using efficacy data from phase 2/3 studies of the 3-DAA regimen demonstrated that the lower dasabuvir C _trough for the 3QD regimen (under fed condition) would have minimal impact on sustained virologic response at week 12 post-treatment (SVR₁₂). Thus, the pharmacodynamic similarity between the regimens was established and the analyses provided the basis for regulatory approval of the 3QD regimen to treat patients with chronic HCV genotype 1 infection.

Chronic Hepatitis B, C, and D

Chronic hepatitis B, C, and D virus infections contribute significantly to the morbidity and mortality of immunocompromised individuals. To contextualize discussion of these infections in immunocompromised patients, this paper provides an overview of aspects of infection in normal hosts. It then describes differences in disease, diagnostic testing, and therapeutic management observed in immunocompromised patients.

Clinical efficacy and tolerability of direct-acting antivirals in elderly patients with chronic hepatitis C

BACKGROUND

There is a lack of evidence-based data on aged patients with newer direct-acting antivirals (DAAs) and with shorter duration of treatment regimens involving DAAs with or without ribavirin (RBV) and pegylated interferon (Peg IFN).

PATIENTS AND METHODS

Medical records of 240 patients treated with DAAs with or without Peg IFN and RBV between January 2013 and July 2015 were retrospectively analyzed. Patients were divided into two groups: patients aged 65 years and older (N=84) and patients aged younger than 65 years (N=156). Pretreatment baseline patient characteristics, treatment efficacy, factors affecting sustained virologic response at 12 weeks after treatment, and adverse reactions were compared between the groups.

RESULTS

No statistically significant difference was observed with end of treatment response (98.8 vs. 98%, P=0.667) and sustained virologic response at 12 weeks after treatment (93.1 vs. 94.1%, P=0.767) between patients aged 65 and older and those younger than 65 years of age. Fatigue was the most common adverse event recorded (32.5%), followed by anemia (19.6%), leukopenia (11.7%), thrombocytopenia (10%), skin rash (8.3%), and headache (7.9%). The RBV dose was reduced in eight (8%) patients and four patients discontinued the RBV treatment because of severe anemia. RBV dose reduction or discontinuation did not reach statistical significance (P=0.913). Increased fibrosis, cirrhosis, aspartate aminotransferase, alanine aminotransferase, hemoglobin, and platelet levels seem to affect the sustained virologic response in the elderly. Twelve (6.28%) patients failed to respond to treatment and the failure rate was not significant (P=0.767) between the groups.

CONCLUSION

DAAs with or without IFN and RBV in the standard recommended 12 or 24-week treatment regimens are effective, well tolerated, and may be safely extended to elderly patients infected with chronic hepatitis C.

Therapy with ombitasvir/paritaprevir/ritonavir plus dasabuvir is effective and safe for the treatment of genotypes 1 and 4 hepatitis C virus (HCV) infection in patients with severe renal impairment: A multicentre experience

Limited data are available on direct-acting antivirals for treating hepatitis C virus (HCV) infection in patients with severe renal impairment. The aim of this study was to evaluate the effectiveness and safety of ombitasvir/paritaprevir/ritonavir (OBV/PTV/r) ± dasabuvir (DSV) ± ribavirin (RBV) in patients with stage 4 or 5 chronic kidney disease (CKD) and HCV genotype 1 or 4 infection in real clinical practice, and to investigate pharmacological interactions. This retrospective study included patients treated with OBV/PTV/r+DSV±RBV or OBV/PTV/r+RBV with CKD stage 4 (eGFR: 15-29 mL/min/1.73m2 ) or 5 (eGFR<15 mL/min/1.73m2 or requiring dialysis) and HCV infection by genotypes 1 and 4 between April 2015 and October 2015 in nine Spanish centres. Sustained virological response at 12 weeks (SVR12) was assessed, and clinical and laboratory data, fibrosis stage, adverse events and pharmacological interactions were reported. Forty-six patients were included: 10 (21.7%) had CKD stage 4 and 36 (78.2%) CKD stage 5. Seventeen (36.9%) had cirrhosis. SVR12 rate in the intention-to-treat population was 95.7%. Twenty-one (45.6%) received RBV, which was discontinued in two (9.5%) patients. Anaemia (haemoglobin <10 g/dl) occurred in 12 patients (57.1%) with RBV vs 10 (40.0%) without RBV (P=.246). Renal function remained stable during antiviral therapy. Nine patients (19.5%) experienced serious adverse events unrelated to antiviral therapy. Concomitant medication was discontinued or modified in 41.3% of patients. In conclusion, the effectiveness of OBV/PTV/r±DSV±RBV in patients with CKD 4-5 was similar to that observed in those with normal renal function and was not associated with severe adverse events.

Ombitasvir and paritaprevir boosted with ritonavir and combined with dasabuvir for chronic hepatitis C

Hepatitis C is a leading cause of cirrhosis and hepatocellular carcinoma responsible for almost 700,000 deaths worldwide annually. Until 2014, management of HCV infections was based on interferon alfa containing regimens, with efficacy of 40-70% and a high adverse event rate. Interferon-free therapeutic options improved sustained viral response (SVR) rate to >90% and safety profile to placebo-like levels. Areas covered: This article describes all-oral regimen consisting of three direct acting antivirals (DAA) - ombitasvir (OBV), paritaprevir (PTV) and dasabuvir (DSV), which in clinical practice is boosted with ritonavir (r) and sometimes with ribavirin (RBV). This combination is registered for treatment of patients infected with HCV genotype 1 and 4. We focused on the regimen characteristics, pharmacokinetics, risk of resistance as well as efficacy and safety in clinical trials and real world studies. Expert commentary: Combination of OBV/PTV/r±DSV±RBV provides SVR rate of about 95% and good safety profile even in patients with compensated liver cirrhosis and failure with previous therapy. Currently it should be of particular value in areas with a predominance of genotype 1b infections. Due to the complexity and risk of drug to drug interactions, it will probably be replaced in coming few years with pangenotypic combinations of next generation DAAs.

Discovery and preclinical development of dasabuvir for the treatment of hepatitis C infection

Hepatitis C virus (HCV) is a leading cause of liver-related morbidity and mortality. Positively, the introduction of new directly-acting antivirals (DAAs) have led to dramatic improvements in response rates to antiviral therapy. Furthermore, newer generations of DAAs have demonstrated better safety profiles as well as efficacy than older generations. Current treatment recommendations are based on different combinations of DAAs. Current combination therapies rely on agents that target the different steps of viral replication by using different molecules from various DAAs families. Areas covered: In this review, the authors summarize data from of one of the recently developed NS5B polymerase inhibitors, dasabuvir, formerly known as ABT-333. Herein, the authors discuss the drug discovery data for dasabuvir including data from preclinical, toxicological resistance studies. The authors also review dasabuvir's clinical efficacy across various clinical challenges, in addition to its limitations in clinical practice. Expert opinion: Dasabuvir represents an important medical advance when used as a combination therapy for HCV. Unfortunately, it does present limitations like low genotypic coverage and further research is still required to address some of the lingering issues.