A combination of nirmatrelvir and ombitasvir boosts inhibition of SARS-CoV-2 replication

Antiviral therapeutics are highly effective countermeasures for the treatment of coronavirus disease 2019 (COVID-19). However, development of resistance to antivirals undermines their effectiveness. Combining multiple antivirals during patient treatment has the potential to overcome the evolutionary selective pressure towards antiviral resistance, as well as provide a more robust and efficacious treatment option. The current evidence for effective antiviral combinations to inhibit severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) replication is limited. Here, we demonstrate a combination of nirmatrelvir with ombitasvir, to jointly bring about potent inhibition of SARS-CoV-2 replication. We developed an in vitro 384- well plate cytopathic effect assay for the evaluation of antiviral combinations against Calu-3 cells infected with SARS-CoV-2 and found, that a combination of ombitasvir and nirmatrelvir was synergistic; thereby decreasing the nirmatrelvir IC50 by approx. 16-fold. The increased potency of the nirmatrelvir-ombitasvir combination, over nirmatrelvir alone afforded a greater than 3 log10 reduction in viral titre, which is sufficient to fully prevent the detection of progeny SARS-CoV-2 viral particles at 48 h post infection. The mechanism of this potentiated effect was shown to be, in-part, due to joint inhibition of the 3-chymotrypsin-like protease via a positive allosteric modulation mechanism.

Effectiveness and safety of generic and brand direct acting antivirals for treatment of chronic hepatitis C

BACKGROUND

Direct acting antivirals (DAAs) are a very effective treatment for hepatitis C virus (HCV). However, brand DAAs are expensive. The licensing of cheaper generic DAAs may address this issue, but there is a lack of clinical studies comparing the efficacy of generic vs brand DAA formulations.

AIM

To compare the efficacy and safety of generic against brand DAAs for chronic hepatitis C treatment in Bahrain.

METHODS

This was a retrospective observational study involving 289 patients with chronic HCV infection during 2016 to 2018. There were 149 patients who were treated with brand DAAs, while 140 patients were treated with generic DAAs. Commonly used DAAs were Ombitasvir/Paritaprevir/Ritonavir ± Dasabuvir ± Ribavirin, and Sofosbuvir/Daclatasvir ± Ribavirin. SVR at 12 wk post treatment was the main outcome variable.

RESULTS

Overall, 87 patients (30.1%) had cirrhosis and 68.2% had genotype 1 HCV infection. At 12 wk post treatment, SVR was achieved by 271 (93.8%) of the patients. In patients who were treated with generic medications, 134 (95.7%) achieved SVR at 12 wk post treatment, compared to 137 (91.9%) among those treated with brand medications (P = 0.19). Having cirrhosis [odds ratio (OR): 9.41, 95% confidence interval (CI): 2.47–35.84] and having HCV genotype 3 (OR: 3.56, 95%CI: 1.03–12.38) were significant independent predictors of not achieving SVR. Alanine transaminase, gamma-glutamyl transpeptidase, and total bilirubin levels decreased significantly following therapy with both generic and brand DAAs.

CONCLUSION

Generic and brand DAAs demonstrate comparable effectiveness in the treatment of chronic hepatitis C patients. Both are safe and equally effective in improving biochemical markers of hepatic inflammation.

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.

A SEVERE CASE OF HYPERGLYCEMIA IN A KIDNEY TRANSPLANT RECIPIENT UNDERGOING INTERFERON-FREE THERAPY FOR CHRONIC HEPATITIS C

CONTEXT

Hepatitis C and diabetes represent important health problems globally. The new-onset diabetes after transplantation is a particular entity that appears due to the use of immunosuppression among transplanted patients.

OBJECTIVE

We aim to describe the clinical and biological aspects of severe hyperglycemia in a kidney transplant recipient undergoing Interferon-free therapy for chronic hepatitis C, discussing the interference of different factors with the glucose metabolism.

DESIGN

The occurrence of diabetes in a patient with history of renal transplantation and Interferon-free treated hepatitis C was studied from both clinical and paraclinical points of view.

SUBJECTS AND METHODS

When presenting to the hospital, extensive blood tests were performed on the patient, revealing significant hyperglycemia and an elevated level of blood tacrolimus. Creatinine clearance was calculated. ECG presented T-wave alterations. Intensive insulin protocol was applied, the case being managed in a multidisciplinary approach.

RESULTS

Blood glucose and tacrolimus were slowly normalized, under therapy. The antiviral treatment was continued, with the achievement of sustained virologic response.

CONCLUSIONS

Diabetes mellitus can have many causes, hepatitis C and transplantation both having an impact on glucose metabolism. The association of the three entities should be carefully managed, due to its enhancing effect on morbidity and mortality.

Safety and efficacy of ombitasvir/paritaprevir/ritonavir/dasabuvir plus ribavirin in patients over 65 years with HCV genotype 1 cirrhosis

PURPOSE

To analyse safety and efficacy of treatment based on ombitasvir/paritaprevir/ritonavir/dasabuvir plus ribavirin in the sub-group of GT1 patients older than 65 years.

METHODS

We collected data extracted from the ABACUS compassionate-use nationwide Italian programme, in patients with cirrhosis due to hepatitis C virus (HCV) Genotype-1 (GT1) or 4 and at high risk of decompensation. GT1-HCV-infected patients received once-daily ombitasvir/paritaprevir, with the pharmacokinetic enhancer ritonavir (25/150/100 mg) and twice-daily dasabuvir (250 mg) plus Ribavirin (RBV) (OBV/PTV/r + DSV + RBV) for 12 (GT1b) or 24 (GT1a) weeks. Endpoints were to evaluate safety and efficacy, the latter defined as HCV RNA negative 12 weeks after the end of treatment (SVR12).

RESULTS

Patients who suffered any adverse event (AE) were 74/240 (30.8%); 13/240 (5.4%) discontinued the treatment. A multivariate analysis found albumin < 3.5 g/dL (OR 2.04: 95% CI 1.0-4.2, p < 0.05) and hypertension (OR 4.6: 95% CI 2.3-9.2, p < 0.001) as variables independently associated with AE occurrence. The SVR12 was 95% (228/240). Multivariate analysis identified baseline bilirubin < 2 mg/dL (OR 4.9: 95% CI 1.17-20.71, p = 0.029) as the only variable independently associated with SVR12.

CONCLUSION

Our findings suggest that OBV/PTV/r + DSV + RBV is safe and effective in real-life use in patients with compensated cirrhosis, HCV-GT1 infection, and age over 65.

Potential drug-drug interactions of OMBITASVIR, PARITAPREVIR/ritonavir ± DASABUVIR ± ribavirin in clinical practice

BACKGROUND & AIMS

Drug-drug interactions (DDIs) with ombitasvir/paritaprevir/ritonavir with or without dasabuvir and with or without ribavirin (OBV/PTV/r ± DSV ± RBV) are common in clinical trials. Our aim was to analyze the prevalence and management of potential DDIs and adverse events (AEs) related to DDIs in patients with chronic hepatitis C (CHC) receiving OBV/PTV/r ± DSV ± RBV in clinical practice.

METHODS

177 CHC patients started OBV/PTV/r ± DSV ± RBV in 4 Spanish hospitals and were screened for potential DDIs using the University of Liverpool database. Patients were classified according to the most serious potential DDIs at baseline and AEs during therapy.

RESULTS

At least one potential DDI was found in 110 (62.1%) patients: 100 (56.5%) had at least one manageable potential DDI and 10 (5.6%) at least one contraindicated. Patients with potential DDIs were receiving a higher number of concomitant drugs (4 vs. 2, P < 0.001). Routine medication was modified at baseline due to potential DDIs in 49 (27.7%) patients. During antiviral treatment, 67 (37.9%) patients presented at least one AE. In 9 (4.5%) patients, a DDI was suspected between OBV/PTV/r ± DSV ± RBV and the concomitant drug, requiring antiviral discontinuation in 4 patients.

CONCLUSIONS

Potential DDIs are frequent with OBV/PTV/r ± DSV ± RBV, although a change in baseline medication is made in only one-quarter of patients. More than half of potential DDIs were only followed, and only 5% of patients developed AEs in which the implication of DDIs could not be excluded.

Retreatment Efficacy of Sofosbuvir/Ombitasvir/Paritaprevir/Ritonavir + Ribavirin for Hepatitis C Virus Genotype 4 Patients

BACKGROUND

The current standard of care for patients with chronic hepatitis C virus (HCV) infection is a combination of direct-acting antiviral agents (DAAs). However, rare clinical trials have been reported on the combination regimen of sofosbuvir (SOF) with ombitasvir, paritaprevir, and ritonavir (OBV/PTV/r) plus ribavirin (RBV) for treated patients with HCV genotype 4 (GT4) infection.

AIMS

To clarify the retreatment efficacy and safety of the recent regimen, SOF with OBV/PTV/r + RBV, for chronic HCV GT4-experienced patients who failed treatment with DAA-based regimens.

METHODS

A total of 113 treatment-experienced patients were allocated for the completion of their treatment period. The enrolled patients were treated orally with SOF plus a fixed dose combination of OBV/PTV/r + RBV, which was administered orally based on the patients' tolerability. The primary end point was a sustained virological response (HCV RNA < 15 IU/mL), observed 12 weeks after the end of the treatment (SVR12).

RESULTS

Among all patients, the treatment-experienced patients with SOF plus OBV/PTV/r + RBV had a higher SVR12 rate (97%; 109/113). Further, SVR12 was achieved by 98% (81/83) of non-cirrhotic patients and 93% (28/30) of cirrhotic patients. Additionally, the most common adverse events reported included fatigue, headache, insomnia, nausea, and dyspnea.

CONCLUSIONS

The recent multi-targeted regimen of SOF plus OBV/PTV/r + RBV was well tolerated and achieved excellent SVR rates among retreatment-experienced Egyptian patients with prior DAA treatments failure, thus providing an alternative regimen for the retreatment of difficult-to-cure HCV GT4 patients.

Paritaprevir/Ritonavir/Ombitasvir Plus Dasabuvir Regimen in the Treatment of Genotype 1 Chronic Hepatitis C Infection in Patients with Severe Renal Impairment and End-Stage Renal Disease: a Real-Life Cohort

BACKGROUND/AIMS

Chronic hepatitis C (HCV) virus infection reactivates under immunosuppressive drugs and therefore has a negative impact on long-term survival of kidney transplant recipients. Treatment-induced clearance of hepatitis C virus (HCV) in kidney transplant candidates prevents virus reactivation after transplantation. Paritaprevir/Ritonavir/Ombitasvir with Dasabuvir (PrOD) represents a highly effective treatment regimen for HCV genotype 1 (GT1), also suitable for patients with end-stage renal disease (ESRD). Serious drug-drug interactions may represent a limiting factor of this regimen. The aim of this retrospective study was to evaluate safety, efficacy and drug-drug interactions management associated with PrOD treatment in the Czech real-world cohort.

METHODS

Emphasizing concomitant medication adjustment, we described the treatment course with PrOD regimen in 23 patients (4 with CKD4 and 19 on maintenance haemodialysis) infected with HCV GT1 (21 GT1b, 2 GT1a), 18 males and 5 females with an average age of 53.7 years. Six patients had compensated liver cirrhosis and 3 of them were liver transplant recipients.

RESULTS

All 23 patients completed the 12-week treatment and achieved sustained virological response 12 weeks after the treatment (SVR12 rate 100%). None of the patients presented with a significant decrease in haemoglobin level, white blood cell and platelet count during the treatment period. The most frequent adverse events were nausea, hypotension, diarrhoea, and hyperkalemia. Four patients presented with a serious adverse event unrelated to the antiviral drugs (salmonellosis, non-functional kidney graft rejection, early gastric cancer, renal cyst infection, initiation of haemodialysis). Concomitant medication had to be modified with the treatment initiation in 10 out of 23 (43.5%) patients (calcium channel blockers, ACE inhibitors, statins, diuretics, tacrolimus); four patients required further adjustment of antihypertensive drugs or tacrolimus dosage on-treatment.

CONCLUSION

PrOD regimen demonstrated an excellent efficacy and good tolerability. Both prospective adjustment of concomitant medication and further on-treatment adjustment allowed for a safe treatment course.

Paritaprevir/ritonavir/ombitasvir plus dasabuvir in HIV/HCV-coinfected patients with genotype 1 in real-life practice

Background Data on the efficacy, safety, and concomitant use with other drugs of the combination ritonavir-boosted paritaprevir/ombitasvir plus dasabuvir (PrOD) in HIV/HCV-coinfected patients in real life are limited. The objectives of this study were to analyze these topics in HIV/HCV-coinfected subjects bearing HCV genotype 1 (GT1). Methods One hundred and eighty-two HIV/HCV-coinfected patients with GT1 (87 1a, 71 1b, 23 other) treated with PrOD, plus ribavirin (RBV) in 119 cases, in routine clinical practice were analyzed. The main variable of efficacy was sustained virological response (SVR) 12 weeks after completing therapy in an intention-to-treat (ITT) analysis and that of safety treatment discontinuation because of adverse effects. Factors associated with SVR were analyzed with a modified ITT (mITT) strategy. Results One hundred and seventy-two (94%) patients attained SVR, 3 (2%) experienced a relapse and two (1%) discontinued therapy due to adverse events. The rates of SVR in subjects with GT 1a and 1b by mITT were, respectively, 97% and 98%. Sixty-five (98%) out of 66 patients with cirrhosis and 107 (98%) out of 110 (p = 1) non-cirrhotics achieved SVR. Fifty-five (95%) patients on concomitant darunavir therapy developed SVR vs. 117 (99%) (p = 0.105) of those without DRV. RBV dose was reduced in 13 (11%) patients and permanently discontinued in 2 (2%), with no impact on SVR. Conclusions PrOD is highly effective and well tolerated in HIV/HCV-coinfected patients with GT1 in routine clinical practice. RBV is often required. However, RBV dose reduction or discontinuation is uncommonly needed and do not impair the SVR rate.

Design, synthesis and identification of silicon-containing HCV NS5A inhibitors with pan-genotype activity

Modification of a HCV NS5A inhibitor, ombitasvir, led to the identification of 10d with improved pan-genotype NS5A inhibition and better pharmacokinetic properties. The key structural changes to ombitasvir include bioisosteric replacement of carbon with silicon atom. Compared with ombitasvir, the activity of anti-HCV genotypes (GT 1 to 6) of 10d is increased to some extent, especially the inhibitory activity against genotype 3a and 6a is increased by more than seven times, and the dog's in vivo pharmacokinetics properties were also superior to ombitasvir. Further drug evaluation showed that 10d was similar to ombitasvir on plasma protein binding and liver distribution profiles, with no cytotoxicity and no inhibitory effect on both CYP 450 and hERG ligand binding. However, permeability assay results indicated that 10d was not the substrate of P-gp or BCRP transporter, which is different from that of ombitasvir. The results of a 14-day repeat-dose toxicity study identified no toxicity with 10d. Our findings in preclinical tests suggest that the silicon-containing compound 10d could be worthy of continued study as a potential drug candidate.

Effect of Hepatitis C Treatment with Ombitasvir/Paritaprevir/R + Dasabuvir on Renal, Cardiovascular and Metabolic Extrahepatic Manifestations: A Post-Hoc Analysis of Phase 3 Clinical Trials

INTRODUCTION

We analyzed phase 3 trial data of ombitasvir/paritaprevir/ritonavir and dasabuvir (3D) ± ribavirin (RBV) in genotype 1 chronic hepatitis C patients to investigate the impact of 3D ± RBV on renal, cardiovascular and metabolic extrahepatic manifestations (EHMs), including persistency 52 weeks post treatment and differential impact by EHM disease severity.

METHODS

Estimated glomerular filtration rate (eGFR), fasting triglyceride and fasting glucose values from clinical trials were used to assess renal, cardiovascular and metabolic EHMs, respectively. Two placebo-controlled trials were used to study the effect of treatment, while the pooled sample of treated patients was used to study the persistency and differential effect of treatment by baseline EHM disease severity, as defined by baseline values of respective EHM biomarkers. Changes in EHM outcomes from baseline were assessed with mixed models adjusting for patient baseline demographic and clinical characteristics.

RESULTS

Treatment with 3D ± RBV resulted in statistically significant declines from baseline of triglycerides and glucose and no statistical change in eGFR. By 52 weeks post treatment patients with elevated triglycerides (-35.3 mg/dl), pre-diabetes (-4.4 mg/dl), diabetes (-34.2 mg/dl) and CKD stage 3 (+1.6 ml/min/1.73 m2) at baseline experienced a statistically significant improvement in their respective EHM values. Patients with CKD stages 2, 4 and 5 experienced no statistically significant change in eGFR from baseline.

CONCLUSION

Treatment with 3D ± RBV resulted in improvement or no worsening of cardiovascular, metabolic and renal EHM markers, especially in patients with severe EHMs at baseline, which persisted until 52 weeks post treatment.

FUNDING

Abbvie Inc.

Safety of the 2D/3D direct-acting antiviral regimen in HCV-induced Child-Pugh A cirrhosis - A pooled analysis

BACKGROUND & AIMS

Chronic hepatitis C virus (HCV)-infected patients with cirrhosis are a high-priority population for treatment. To help inform the benefit-risk profile of the all-oral direct-acting antiviral (DAA) combination regimen of ombitasvir, paritaprevir, and ritonavir, with or without dasabuvir (OBV/PTV/r±DSV) in patients with Child-Pugh A cirrhosis, we undertook a comprehensive review of AbbVie-sponsored clinical trials enrolling patients with Child-Pugh A cirrhosis.

METHODS

Twelve phase II or III clinical trials of the 2-DAA regimen of OBV/PTV/r±ribavirin (RBV) or the 3-DAA regimen of OBV/PTV/r+DSV±RBV that included patients with Child-Pugh A cirrhosis were reviewed; patients who completed treatment by November 16, 2015 were included in a pooled, post hoc safety assessment. The number and percentage of patients with treatment-emergent adverse events (TEAEs), serious TEAEs, and TEAEs consistent with hepatic decompensation were reported.

RESULTS

In 1,066 patients with Child-Pugh A cirrhosis, rates of serious TEAEs and TEAEs leading to study drug discontinuation were 5.3% (95% confidence interval [CI]: 4.1-6.8) and 2.2% (95% CI: 1.4-3.2), respectively. Thirteen patients (1.2%; 95% CI: 0.7-2.1) had a TEAE that was consistent with hepatic decompensation. The most frequent TEAEs consistent with hepatic decompensation were ascites (n=8), esophageal variceal hemorrhage (n=4), and hepatic encephalopathy (n=2).

CONCLUSIONS

This pooled analysis in 1,066 HCV-infected patients with Child-Pugh A cirrhosis confirms the safety of OBV/PTV/r±DSV±RBV in this population. These results support the use of OBV/PTV/r±DSV±RBV in this high-priority population. Lay summary: This pooled safety analysis in 1,066 HCV-infected patients with compensated cirrhosis, receiving treatment with ombitasvir, paritaprevir, and ritonavir with or without dasabuvir, with or without ribavirin, shows that the rate of hepatic decompensation events was similar to previously reported rates in untreated patients.

Effectiveness, safety and clinical outcomes of direct-acting antiviral therapy in HCV genotype 1 infection: Results from a Spanish real-world cohort

BACKGROUND & AIMS

Clinical trials evaluating second-generation direct-acting antiviral agents (DAAs) have shown excellent rates of sustained virologic response (SVR) and good safety profiles in patients with chronic hepatitis C virus (HCV) genotype 1 infection. We aimed to investigate the effectiveness and safety of two oral DAA combination regimens, ombitasvir/paritaprevir/ritonavir plus dasabuvir (OMV/PTV/r+DSV) and ledipasvir/sofosbuvir (LDV/SOF), in a real-world clinical practice.

METHODS

Data from HCV genotype 1 patients treated with either OMV/PTV/r+DSV±ribavirin (RBV) (n=1567) or LDV/SOF±RBV (n=1758) in 35 centers across Spain between April 1, 2015 and February 28, 2016 were recorded in a large national database. Demographic, clinical and virological data were analyzed. Details of serious adverse events (SAEs) were recorded.

RESULTS

The two cohorts were not matched with respect to baseline characteristics and could not be compared directly. The SVR12 rate was 96.8% with OMV/PTVr/DSV±RBV and 95.8% with LDV/SOF±RBV. No significant differences were observed in SVR according to HCV subgenotype (p=0.321 [OMV/PTV/r+DSV±RBV] and p=0.174 [LDV/SOF]) or degree of fibrosis (c0.548 [OMV/PTV/r/DSV±RBV] and p=0.085 [LDV/SOF]). Only baseline albumin level was significantly associated with failure to achieve SVR (p<0.05) on multivariate analysis. Rates of SAEs and SAE-associated treatment discontinuation were 5.4% and 1.7%, in the OMV/PTV/r+DSV subcohort and 5.5% and 1.5% in the LDV/SOF subcohort, respectively. Hepatocellular carcinoma (HCC) recurred in 30% of patients with a complete response to therapy for previous HCC. Incident HCC was reported in 0.93%.

CONCLUSIONS

In this large cohort of patients managed in the real-world setting in Spain, OMV/PTV/r+DSV and LDV/SOF achieved high rates of SVR12, comparable to those observed in randomized controlled trials, with similarly good safety profiles.

LAY SUMMARY

In clinical trials, second-generation direct-acting antiviral agents (DAAs) have been shown to cure over 90% of patients chronically infected with the genotype 1 hepatitis C virus and have been better tolerated than previous treatment regimens. However, patients enrolled in clinical trials do not reflect the real patient population encountered in routine practice. The current study, which includes almost 4,000 patients, demonstrates comparable rates of cure with two increasingly used DAA combinations as those observed in the clinical trial environment, confirming that clinical trial findings with DAAs translate into the real-world setting, where patient populations are more diverse and complex.

The Liver Meeting 2016 - American Association for the Study of Liver Diseases, 67th Annual Meeting (November 11-15, 2016 - Boston, Massachusetts, USA)

This year, The Liver Meeting, organized by the American Association for the Study of Liver Diseases, was held at the Hynes Convention Center in Boston, Massachusetts (USA). During the 4-day conference, scientists and researchers from all over the world discussed recent results and advances in the field of hepatology. New research with experimental, as well as investigational, therapeutic candidates was presented in several poster sessions as well as oral presentations. The reports from this meeting provide an overview of some of the most important presentations.

Ultra-performance liquid chromatography tandem mass spectrometry for determination of Direct Acting Antiviral drugs in human liver fine needle aspirates

An ultra-performance liquid chromatography with triple quadrupole mass spectrometry method was developed and validated for the determination of direct acting antiviral drug concentrations in human liver fine needle aspirates. Liver fine needle aspirate (FNA) biopsy samples were homogenized in acetonitrile to stabilize the analytes and precipitate protein. The acetonitrile supernatants were diluted with internal standards and mobile phase. Separation was achieved with a Waters Acquity BEH C18 column (50×2.1mm, 1.7um) with a gradient elution of 0.1% formic acid in water and acetonitrile. The total run time was 4.25min. Detection of analytes was achieved using electrospray ionization (positive mode) and triple quadrupole selected reaction monitoring. Standard curve concentrations ranged from 12.5 to 5000ng/mL for dasabuvir and the m1 metabolite of dasabuvir, 1.25 to 2500ng/mL for ombitasvir and ritonavir, and 5.00 to 5000ng/mL for paritaprevir. The intra- and inter-day accuracy and precision were less than 13.7% in low, medium, and high quality control samples. The validated method was applied to the analysis of a liver fine needle aspirate of a patient undergoing direct acting antiviral therapy for hepatitis C virus.

Simultaneous determination of newly developed antiviral agents in pharmaceutical formulations by HPLC-DAD

Background

Ombitasvir/paritaprevir/ritonavir/dasabuvir (Viekira Pak^®) are the newest medicines approved for use in the treatment of hepatitis C virus (HCV) and are available in tablet form as an oral combination. Specifically, these agents are indicated in the treatment of HCV in patients with genotype 1 infection. Due to the therapeutic importance and increased use of Viekira Pak, proper methods for its determination in bulk and pharmaceutical formulations must be developed.

Results

The present study describes the development and validation of a simple, rapid, selective and economical reverse phase high performance liquid chromatography-diode array detection (HPLC-DAD) method for the simultaneous determination of paritaprevir (PAR), ombitasvir (OMB), dasabuvir(DAS) and ritonavir (RIT) in bulk and pharmaceutical preparations. The proposed method was carried out using an RPC₁₈ column (150 × 4.5 mm, 3.5 μ), with a mobile phase consisting of 10 mM phosphate buffer (pH 7)and acetonitrile (35:65, v/v) at a flow rate of 1 ml/min and a detection wavelength of 254 nm. Sorafenib (SOR) was selected as the internal standard to ensure that the quantitative performance was high. The method was validated based on its specificity, linearity, limit of detection, limit of quantitation, accuracy, precision, robustness and stability. The calibration curves for PAR, DAS, RIT and OMB were linear at 2.5–60, 1.25–30, 1.7–40 and 0.42–10 μg/ml, respectively, and all of the correlation coefficients were >0.999.

Conclusions

The proposed method was successfully applied for the determination of ombitasvir/paritaprevir/ritonavir/dasabuvirin tablets, without interference from the excipient peaks. Hence, the method can be applied for the routine quality control analysis of the studied drugs, either in bulk or dosed forms.Graphical abstract

Exposure-Response Relationship for Ombitasvir and Paritaprevir/Ritonavir in Hepatitis C Virus Subgenotype 1b-Infected Japanese Patients in the Phase 3 Randomized GIFT-I Study

INTRODUCTION

The all-oral 2 direct-acting antiviral (DAA) regimen of ombitasvir/paritaprevir/ritonavir 25/150/100 mg once a day has been evaluated in hepatitis C virus subgenotype 1b-infected Japanese adults in the GIFT-I study. The aim of this analysis was to evaluate potential relationships between DAA exposures and laboratory abnormalities/adverse events of peripheral edema in patients in GIFT-I.

METHODS

The GIFT-I study consisted of a randomized, double-blind, placebo-controlled substudy in patients without cirrhosis and an open-label substudy in patients with compensated cirrhosis. Patients received ombitasvir/paritaprevir/ritonavir for 12 weeks. Exposure-response relationships between individual components of the ombitasvir/paritaprevir/ritonavir regimen and clinical parameters of interest were explored using pharmacokinetic and clinical data from patients in the study. Graphical analyses were performed. For events that occurred in at least 10 patients (total bilirubin elevation ≥grade 2 and peripheral edema ≥grade 1), multivariate logistic regression analyses were used to identify significant relationships between predictor variables (drug exposures) and response variables (probability of adverse events or laboratory abnormalities), with consideration for the effect of potential covariates and baseline status of response variables.

RESULTS

Data from 321 noncirrhotic and 42 compensated cirrhotic patients were analyzed. There were 14 events of peripheral edema (10 at grade 1 and 4 at grade 2) in patients who received concomitant administration of calcium channel blockers and ombitasvir/paritaprevir/ritonavir. There was no apparent relationship between the incidences of peripheral edema and exposures of paritaprevir, ombitasvir, or ritonavir. There was a shallow relationship between total bilirubin elevation and exposures of paritaprevir which is an inhibitor of bilirubin transporter organic anion-transporting polypeptide 1B. Based on graphical analyses, exposures of paritaprevir, ombitasvir, or ritonavir were weakly associated with hemoglobin decrease, but not associated with post baseline alanine aminotransferase or aspartate aminotransferase elevations.

CONCLUSIONS

In Japanese patients, there were no associations or only shallow relationships between DAA exposures and peripheral edema or laboratory abnormalities. Consequently, therapeutic drug monitoring is not expected to be beneficial in managing patients on the 2-DAA regimen.

TRIAL REGISTRATION

ClinicalTrials.gov identifier, NCT02023099.

FUNDING

AbbVie Inc.

Ombitasvir, paritaprevir, ritonavir, dasabuvir and ribavirin in cirrhosis after complete destruction of hepatocellular carcinoma

We observed a sustained viral response (SVR) of ombitasvir/paritaprevir/ritonavir, dasabuvir and ribavirin therapy, for 12 wk, in two cases with compensated liver cirrhosis and fully destroyed early hepatocellular carcinoma (HCC). Patients were infected with hepatitis C virus (HCV) genotype 1b and were previous null responders/relapsers to interferon-alpha/ribavirin (IFN/RBV). There was a rapid suppression of HCV RNA to undetectable levels within the first two treatment weeks. SVR was achieved even after marked reduction of the RBV dose. The treatment was well tolerated. Both subjects experienced worsening of liver disease during therapy, in different patterns: severe, transient, predominantly direct hyperbilirubinemia without cytolysis (case 1) or progressive increase of aminotransferases (grade 4) without severe hyperbilirubinemia (case 2). Adverse events spontaneously resolved. The patients remained in a good clinical condition without hepatic decompensation. There was no re-occurrence of HCC. This is the first report for treatment of HCV cirrhosis after complete HCC destruction.

Chronic hepatitis C: This and the new era of treatment

Over the last years it has started a real revolution in the treatment of chronic hepatitis C. This occurred for the availability of direct-acting antiviral agents that allow to reach sustained virologic response in approximately 90% of cases. In the near future further progress will be achieved with the use of pan-genotypic drugs with high efficacy but without side effects.

Hepatitis C Virus: Current and Evolving Treatments for Genotype 4

Hepatitis C virus (HCV) is a major cause of chronic liver disease, with more than 170 million infected individuals worldwide. Genotype 4 is the most frequent cause of chronic hepatitis C in the Middle East and sub-Saharan Africa. It has recently spread to southern Europe. The introduction of all-oral, interferon-free regimens that combine direct-acting antivirals (DAAs) has significantly advanced HCV treatment. High efficacy rates, short treatment duration, and favorable adverse event profiles have been demonstrated with multiple regimens, both with and without ribavirin. This review discusses management of patients with HCV genotype 4 chronic hepatitis, in the era of DAAs.

Regimens for Cirrhotic Patients

Therapy for hepatitis C has entered the era of all-oral direct-acting antiviral agents. Sustained response rates are now greater than 90% for all genotypes, although patients with cirrhosis remain the most difficult to treat. There are limited data for patients with cirrhosis and with hepatitis C genotypes 4 and 6 with cirrhosis. Genotype 3 patients with cirrhosis need additional strategies to achieve the sustained virologic response rates seen in genotype 1 patients with cirrhosis. This article outlines the currently available therapies for patients with cirrhosis and hepatitis C across all genotypes, with suggested management strategies.

All-oral interferon-free treatments: The end of hepatitis C virus story, the dream and the reality

The year 2014 marked the beginning of the end of the interferon era and the triumph of the all-oral interferon-free regimens for treatment of hepatitis C virus (HCV) infection. These innovative therapies are safe and yield a cure rate of over 90%. The scientific hepatology community is euphoric about the possibility of elimination and even eradication of HCV infection. However, the current high cost of the new all-oral regimens allows access to treatment only for a restricted number of HCV-infected patients. In addition, many other conditions such as modality of access and delivery of care, inadequate knowledge of HCV epidemiology and political commitments to be undertaken, hamper the fulfillment of the dream to eliminate the virus. Since, such conditions are not impossible to overcome, a global urgent effort must be made to allow a widespread access to the new treatments which will permit in the next years to avoid million of HCV-related deaths.

Pharmacokinetics and safety of co-administered paritaprevir plus ritonavir, ombitasvir, and dasabuvir in hepatic impairment

BACKGROUND & AIMS

Paritaprevir, ombitasvir, and dasabuvir are direct-acting antivirals for treatment of chronic hepatitis C virus (HCV) infection. The aim of this study was to characterize the effects of mild, moderate, and severe hepatic impairment on the pharmacokinetics of these drugs.

METHODS

HCV-negative subjects with normal hepatic function (n=7) or mild (Child-Pugh A, n=6), moderate (Child-Pugh B, n=6), or severe (Child-Pugh C, n=5) hepatic impairment received a single-dose of the combination of paritaprevir plus ritonavir (paritaprevir/r, 200/100 mg), ombitasvir (25 mg), and dasabuvir (400 mg). Plasma samples were collected through 144 hours after administration for pharmacokinetic assessments.

RESULTS

Paritaprevir, ombitasvir, dasabuvir, and ritonavir exposures (maximal plasma concentration, C(max), and area under the concentration-time curve, AUC) were minimally affected in subjects with mild or moderate hepatic impairment. Differences in exposures between healthy controls and subjects with mild or moderate hepatic impairment were less than 35%, except for 62% higher paritaprevir AUC in subjects with moderate hepatic impairment. Paritaprevir and dasabuvir AUC were significantly higher in subjects with severe hepatic impairment (950% and 325%, respectively). However, ombitasvir AUC was 54% lower and ritonavir AUC was comparable. Adverse events included eye stye, insomnia, and pain from an infiltrated intravenous line.

CONCLUSIONS

The changes observed in paritaprevir, ritonavir, ombitasvir, and dasabuvir exposures in subjects with mild or moderate hepatic impairment do not necessitate dose adjustment. Subjects with severe hepatic impairment had substantially higher paritaprevir and dasabuvir exposures.

Drug-drug interaction profile of the all-oral anti-hepatitis C virus regimen of paritaprevir/ritonavir, ombitasvir, and dasabuvir

BACKGROUND & AIMS

Paritaprevir (administered with ritonavir, PTV/r), ombitasvir (OBV), and dasabuvir (DSV) are direct-acting antiviral agents (DAAs) for the treatment of chronic hepatitis C virus (HCV) infection. Thirteen studies were conducted to characterize drug-drug interactions for the 3D regimen of OBV, PTV/r, and DSV and various medications in healthy volunteers to inform dosing recommendations in HCV-infected patients.

METHODS

Mechanism-based drug-drug interactions were evaluated for gemfibrozil, ketoconazole, carbamazepine, warfarin, omeprazole, digoxin, pravastatin, and rosuvastatin. Drug-drug interactions with medications commonly used in HCV-infected patients were evaluated for amlodipine, furosemide, alprazolam, zolpidem, duloxetine, escitalopram, methadone, buprenorphine/naloxone, and oral contraceptives. Ratios of geometric means with 90% confidence intervals for maximum plasma concentration (Cmax) and area under the plasma concentration-time curve (AUC) were used to determine the magnitude of interaction.

RESULTS

Coadministration with the 3D regimen of OBV, PTV/r, and DSV resulted in a <2-fold change in mean Cmax and AUC for most medications and the DAAs, indicating minimal to modest interactions. Carbamazepine decreased PTV, ritonavir, and DSV exposures substantially, while gemfibrozil increased DSV exposures substantially. Although coadministration with ethinyl estradiol-containing contraceptives resulted in elevated alanine aminotransferase levels, coadministration with a progestin-only contraceptive did not.

CONCLUSIONS

The majority of medications can be coadministered with the 3D regimen of OBV, PTV/r, and DSV without dose adjustment, or with clinical monitoring or dose adjustment. Although no dose adjustment is necessary for the 3D regimen when coadministered with 17 of the 20 medications, coadministration with gemfibrozil, carbamazepine, or ethinyl estradiol-containing contraceptives is contraindicated.