Pharmacokinetics and safety of glecaprevir and pibrentasvir in HCV-negative subjects with hepatic impairment

Cutting-edge pharmacotherapy for hepatitis C virus infection: a comprehensive review

INTRODUCTION

Pharmacotherapy against hepatitis C virus (HCV) infection has tremendously improved since the advent of interferon (IFN)-free direct-acting antivirals (DAAs). Additionally, fixed-dose pangenotypic DAAs, which are safe, potent, easy for use, and can cover a wide spectrum of patients, have been recommended by professional guidelines for DAA-naïve and DAA-experienced patients with HCV.

AREAS COVERED

We review the pharmacokinetics, pharmacodynamics, and potential drug-drug interactions (DDIs) of fixed-dose pangenotypic DAA regimens, including glecaprevir/pibrentasvir (GLE/PIB), sofosbuvir/velpatasvir (SOF/VEL), and sofosbuvir/velpatasvir/voxilaprevir (SOF/VEL/VOX). Additionally, we summarize the efficacy and safety of these regimens in clinical trials as well as real-world studies for treating different populations. Lastly, we discuss unmet medical needs in managing HCV in the era of fixed-dose pangenotypic DAAs.

EXPERT OPINION

Protease inhibitors (PIs), including GLE and VOX, are prone to have more frequent DDIs, compared to the non-structural (NS) 5A and 5B inhibitors. These regimens are generally well tolerated and can be applied to different populations, except for the contraindicated use of PI-containing DAA regimens in decompensated cirrhosis. Using the first-line GLE/PIB and SOF/VEL can eradicate HCV in more than 95% of DAA-naïve patients across different populations. The viral cure usually exceeds 95% when using the rescue SOF/VEL/VOX regimen for prior DAA failures.

Development and validation of a liquid chromatographic-tandem mass spectrometric assay for the quantification of the direct acting antivirals glecaprevir and pibrentasvir in plasma

BACKGROUND

Direct acting antiviral (DAA) therapies are effective in the treatment and management of chronic HCV infections. Glecaprevir (GLE) and pibrentasvir (PIB) are pangenotypic DAAs that are delivered alone or as a fixed-dose oral formulation to treat chronic HCV infections with or without cirrhosis. Sensitive and dynamic bioanalytical assays are needed to understand the pharmacology of GLE and PIB.

METHODS

Drug free K2EDTA plasma was spiked with GLE, PIB, and their internal standards. Drugs were extracted from plasma via protein precipitation, and subsequently quantified using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The method was validated according to regulatory recommendations, and evaluated in remnant plasma samples from individuals prescribed GLE and PIB.

RESULTS

The analytical measuring ranges for GLE and PIB were 0.25-2000 ng/mL and 0.25-1000 ng/mL, respectively. The method showed acceptable accuracy and precision for both DAAs. GLE and PIB in plasma were stable following six freeze thaw cycles and at room temperature for up to 67 h. All analytes were stable in whole blood incubated at room temperature for 24 h, and at 40 °C and 100% humidity for 2 h. Negligible percent matrix effects were observed for PIB and PIB-IS across the measuring range of the assay. Significant ion suppression was observed for GLE, with an average matrix effects of 27.9%. However, relative matrix effects were < 6.3% between drug and internal standard, and deemed acceptable. Assay validation assessments in alternative matrices also met acceptance criteria. Both DAAs were successfully measured in remnant plasma samples from individuals administered GLE and PIB.

CONCLUSIONS

An LC-MS/MS method for GLE and PIB quantification in plasma has been developed and validated. The assay met acceptable performance criteria and may be used in downstream applications to characterize DAA pharmacology for HCV treatment.

Real-world treatment outcome with protease inhibitor direct-acting antiviral in advanced hepatitis C cirrhosis: a REAL-C study

INTRODUCTION

Current guidelines discourage the use of direct-acting antiviral (DAA) containing protease-inhibitor (PI) in advanced HCV cirrhosis. We aimed to compare the real-world tolerability of PI vs. non-PI DAA regimens in this population.

METHODS

We identified advanced cirrhosis patients treated with DAA from the REAL-C registry. The primary outcome was significant worsening or improvement in CPT or MELD scores following DAA treatment.

RESULTS

From the REAL-C registry of 15,837 patients, we included 1077 advanced HCV cirrhosis patients from 27 sites. 42% received PI-based DAA. Compared to non-PI group, the PI group was older, had higher MELD and higher percentage with kidney disease. Inverse probability of treatment weighting (IPTW; matching on age, sex, history of clinical decompensation, MELD, platelet, albumin, Asia site, Asian ethnicity, hypertension, hemoglobin, genotype, liver cancer, ribavirin) was used to balance the two groups. In the IPTW-matched cohorts, the PI and non-PI groups had similar SVR12 (92.9% vs. 90.7%, p = 0.30), similar percentages of significant worsening in CTP or MELD scores at posttreatment week 12 and 24 (23.9% vs. 13.1%, p = 0.07 and 16.5% vs. 14.6%, p = 0.77), and similar frequency of new HCC, decompensating event, and death by posttreatment week 24. In multivariable analysis, PI-based DAA was not associated with significant worsening (adjusted odds ratio = 0.82, 95% CI 0.38-1.77).

CONCLUSION

Tolerability and treatment outcomes were not significantly different in advanced HCV cirrhosis treated with PI-based (vs. non-PI) DAA up to CTP-B or MELD score of 15. Safety of PI-based DAA in those with CTP-C or MELD beyond 15 awaits further data.

Protein Abundance of Drug Metabolizing Enzymes in Human Hepatitis C Livers

Hepatic drug metabolizing enzymes (DMEs), whose activity may be affected by liver diseases, are major determinants of drug pharmacokinetics. Hepatitis C liver samples in different functional states, i.e., the Child-Pugh class A (n = 30), B (n = 21) and C (n = 7) were analyzed for protein abundances (LC-MS/MS) and mRNA levels (qRT-PCR) of 9 CYPs and 4 UGTs enzymes. The protein levels of CYP1A1, CYP2B6, CYP2C8, CYP2C9, and CYP2D6 were not affected by the disease. In the Child-Pugh class A livers, a significant up-regulation of UGT1A1 (to 163% of the controls) was observed. The Child-Pugh class B was associated with down-regulation of the protein abundance of CYP2C19 (to 38% of the controls), CYP2E1 (to 54%), CYP3A4 (to 33%), UGT1A3 (to 69%), and UGT2B7 (to 56%). In the Child-Pugh class C livers, CYP1A2 was found to be reduced (to 52%). A significant trend in down-regulation of the protein abundance was documented for CYP1A2, CYP2C9, CYP3A4, CYP2E1, UGT2B7, and UGT2B15. The results of the study demonstrate that DMEs protein abundances in the liver are affected by hepatitis C virus infection and depend on the severity of the disease.

Risk Factors of Glecaprevir/Pibrentasvir-Induced Liver Injury and Efficacy of Ursodeoxycholic Acid

Although glecaprevir/pibrentasvir (GP) therapy is recommended as a first-line treatment for hepatitis C virus (HCV) infection, serious drug-induced liver injury occasionally develops. The present study aimed to elucidate real-world risk factors for GP-induced liver injury and to evaluate the efficacy of add-on ursodeoxycholic acid (UDCA) for liver injury. We analyzed 236 HCV patients who received GP therapy. GP-induced liver injury was defined as any elevation to grade ≥ 1 in total bilirubin (TB), aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), or γ-glutamyl transferase (γ-GT) during treatment without other cause. The frequency of GP-induced liver injury was 61.9% (146/236). Serious elevation to grade ≥ 3 in TB, AST, ALT, ALP, and γ-GT was identified in 3.8% (9/236), 0%, 0%, 0%, and 0.4% (1/209), respectively. Therapy discontinuation and dose reduction were seen in one patient each. Multivariate analysis revealed age and TB as independent risk factors for GP-induced liver injury. In patients with grade ≥ 2 hyperbilirubinemia, TB after onset significantly decreased in the add-on UDCA group but not in the no UDCA group. Careful attention to GP-induced liver injury is warranted for elderly patients with cirrhosis. Add-on UDCA could suppress the aggravation of GP-induced liver injury.

Indirect hyperbilirubinemia and jaundice during chronic hepatitis C in an HIV-infected patient treated with glecaprevir/pibrentasvir (GLE/PIB) and antiretroviral therapy (ART). The first reported case in Italy

Glecaprevir (GLE)/pibrentasvir (PIB) is a pangenotypic direct-acting antiviral regimen approved for treating chronic hepatitis C virus. Primary treatment and re-treatment with GLE/PIB are effective and safe for patients without decompensated liver cirrhosis and chronic hepatitis C in a real-world clinical setting. However, in the context of compensated cirrhosis and concomitant administration of inhibitors of cytochromes, a careful monitoring of liver biomarkers, as well as therapeutic drug monitoring (TDM), may be advisable during GLE/PIB therapy. The GLE / PIB combination is very effective and safe in achieving a sustained virological response, but it can be associated with the development of severe hepatic adverse events, which require virological and serum concentration monitoring of the two drugs to prevent a serious liver damage. The possible onset of hyperbilirubinemia must not necessarily lead to the suspension of therapy, because the phenomenon may be transient. We report what is likely the first known case of severe jaundice after treatment with GLE/PIB in Italy in a patient with compensated chronic hepatitis in the context of HIV disease.

Gadoxetic acid-enhanced magnetic resonance imaging predicts hyperbilirubinemia induced by glecaprevir during hepatitis C virus treatment

Glecaprevir is a substrate for organic anion-transporting polypeptide (OATP) 1B1/1B3, which transports bilirubin. Hyperbilirubinemia is an adverse event during anti-hepatitis C virus treatment with glecaprevir and pibrentasvir. Gadoxetic acid is also transported by OATP1B1/1B3, and we aimed to evaluate whether gadoxetic acid-enhanced magnetic resonance (MR) imaging was associated with glecaprevir trough concentrations (C_trough). We further determined whether this was predictive of hyperbilirubinemia development in a cohort of 33 patients. The contrast enhancement index (CEI), a measure of hepatic enhancement effect on the hepatobiliary image, was assessed. Glecaprevir C_trough was determined 7 days after administration. Five of the 33 patients (15%) developed Common Terminology Criteria for Adverse Events grade ≥ 2 hyperbilirubinemia. We found a negative relationship between CEI and C_trough (r = − 0.726, p < 0.001). The partial correlation coefficient between CEI and C_trough was − 0.654 (p < 0.001), while excluding the effects of albumin, FIB-4 index, and indirect bilirubin at baseline. The C_trough was significantly higher in patients with hyperbilirubinemia than in those without (p = 0.008). In multivariate analysis, CEI ≤ 1.71 was an independent factor influencing the development of hyperbilirubinemia (p = 0.046). Our findings indicate that gadoxetic acid MR imaging can help predict glecaprevir concentration and development of hyperbilirubinemia.

Viral Hepatitis C Therapy: Pharmacokinetic and Pharmacodynamic Considerations: A 2019 Update

It has been estimated by the World Health Organization (WHO) that over 71 million people were infected with the hepatitis C virus (HCV) in 2015. Since then, a number of highly effective direct-acting antiviral (DAA) regimens have been licensed for the treatment of chronic HCV infection: sofosbuvir/daclatasvir, sofosbuvir/ledipasvir, elbasvir/grazoprevir, sofosbuvir/velpatasvir, glecaprevir/pibrentasvir, and sofosbuvir/velpatasvir/voxilaprevir. With these treatment regimens, almost all chronic HCV-infected patients, even including prior DAA failures, can be treated effectively and safely. It is therefore likely that further development of DAAs will be limited. In this descriptive review we provide an overview of the clinical pharmacokinetic characteristics of currently available DAAs by describing their absorption, distribution, metabolism, and excretion. Potential drug-drug interactions with the DAAs are briefly discussed. Furthermore, we summarize what is known about the pharmacodynamics of the DAAs in terms of efficacy and safety. We briefly discuss the relationship between the pharmacokinetics of the DAAs and efficacy or toxicity in special populations, such as hard to cure patients and patients with liver cirrhosis, liver transplantation, renal impairment, hepatitis B virus or HIV co-infection, bleeding disorders, and children. The aim of this overview is to educate/update prescribers and pharmacists so that they are able to safely and effectively treat HCV-infected patients even in the presence of underlying co-infections or co-morbidities.

A case report of glecaprevir/pibrentasvir-induced severe hyperbilirubinemia in a patient with compensated liver cirrhosis

RATIONALE

Glecaprevir/pibrentasvir, a pan-genotypic and ribavirin-free direct acting antiviral agent regimen, has shown significant efficacy and very few serious complications. However, as the drug metabolizes in the liver, it is not recommended in patients with decompensated liver cirrhosis. Herein, we report the case of a patient with compensated liver cirrhosis who developed severe jaundice after glecaprevir/pibrentasvir medication.

PATIENT CONCERNS

A 77-year-old man diagnosed with chronic hepatitis C-related compensated liver cirrhosis visited hospital due to severe jaundice after 12 weeks of glecaprevir/pibrentasvir medication.

DIAGNOSES

On the laboratory work-up, the total/direct bilirubin level was markedly elevated to 21.56/11.68 from 1.81 mg/dL; the alanine aminotransferase and aspartate aminotransferase levels were within the normal range. We checked the plasma drug concentration level of glecaprevir, and 18,500 ng/mL was detected, which was more than 15 times higher than the drug concentration level verified in normal healthy adults.

INTERVENTIONS

Glecaprevir/pibrentasvir was abruptly stopped and after 6 days, the drug concentration level decreased to 35 ng/mL and the serum total/direct bilirubin decreased to 7.49/4.06 mg/dL.

OUTCOMES

Three months after drug cessation, the serum total bilirubin level normalized to 1.21 mg/dL and HCV RNA was not detected.

LESSONS

We report what is likely the first known case of severe jaundice after medication with glecaprevir/pibrentasvir in a patient with compensated liver cirrhosis. Clinicians should bear potential hyperbilirubinemia in mind when treating chronic hepatitis C with this regimen and should monitor the patient closely during follow-up laboratory exams, especially in elderly cirrhotic patients.