Pharmacokinetics, Safety, and Tolerability of Glecaprevir and Pibrentasvir in Healthy White, Chinese, and Japanese Adult Subjects

Pharmacokinetics, Tolerability, and Safety of Glecaprevir/Pibrentasvir Co-formulated Bilayer Tablet Following Repeated Administration in Healthy Chinese Adults

Glecaprevir (GLE)/pibrentasvir (PIB) is an all-oral, interferon- and ribavirin-free, pan-genotypic fixed-dose combination regimen approved for the treatment of all major genotypes of hepatitis C virus (HCV) infection in many countries worldwide. To support clinical development in China, an open-label, single-center phase 1 study was conducted to evaluate the pharmacokinetics, safety, and tolerability of GLE/PIB in healthy Chinese adults in Mainland China. Eighteen participants received 3 tablets of coformulated GLE/PIB 100/40 mg once daily (QD) for 7 days. Following GLE/PIB 300 mg/120 mg administration, GLE and PIB reached maximum concentration in 4-5 hours with a terminal elimination half-life of 5.9 and 25 hours, respectively. Both GLE and PIB reached steady state by day 5, with no-to-minimal accumulation (≤17% higher). GLE/PIB exposures in healthy Chinese participants were similar to historical observations across phase 1 studies in healthy Western participants. GLE/PIB was safe and well-tolerated, with most adverse events being mild. These pharmacokinetics and safety data, together with existing global efficacy and safety data in healthy and HCV-infected Western participants, support the use of GLE/PIB 300 mg/120 mg QD in adult Chinese patients with chronic HCV infection.

Mechanisms and Clinical Significance of Pharmacokinetic Drug Interactions Mediated by FDA and EMA-approved Hepatitis C Direct-Acting Antiviral Agents

The treatment of patients infected with the hepatitis C virus (HCV) has been revolutionised by the development of direct-acting antiviral agents (DAAs) that target specific HCV proteins involved in viral replication. The first DAAs were associated with clinical problems such as adverse drug reactions and pharmacokinetic drug-drug interactions (DDIs). Current FDA/EMA-approved treatments are combinations of DAAs that simultaneously target the HCV N5A-protein, the HCV N5B-polymerase and the HCV NS3/4A-protease. Adverse events and DDIs are less likely with these DAA combinations but several DDIs of potential clinical significance remain. Much of the available information on the interaction of DAAs with CYP drug-metabolising enzymes and influx and efflux transporters is contained in regulatory summaries and is focused on DDIs of likely clinical importance. Important DDIs perpetrated by current DAAs include increases in the pharmacokinetic exposure to statins and dabigatran. Some mechanistic information can be deduced. Although the free concentrations of DAAs in serum are very low, a number of these DDIs are likely mediated by the inhibition of systemic influx transporters, especially OATP1B1/1B3. Other DDIs may arise by DAA-mediated inhibition of intestinal efflux transporters, which increases the systemic concentrations of some coadministered drugs. Conversely, DAAs are victims of DDIs mediated by cyclosporin, ketoconazole, omeprazole and HIV antiretroviral drug combinations, especially when boosted by ritonavir and, to a lesser extent, cobicistat. In addition, concurrent administration of inducers, such as rifampicin, carbamazepine and efavirenz, decreases exposure to some DAAs. Drug-drug interactions that increase the accumulation of HCV N3/4A-protease inhibitors like grazoprevir may exacerbate hepatic injury in HCV patients.

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.

Efficacy and Safety of Glecaprevir/Pibrentasvir in Patients with Chronic HCV Infection

Hepatitis C virus (HCV) infection is a major cause of end-stage liver disease, including decompensated cirrhosis and hepatocellular carcinoma. Over 95% of patients with HCV infection have achieved sustained virologic response at 12 weeks under the treatment of several pan-genotypic regimens approved for patients with HCV infection. The glecaprevir/pibrentasvir (G/P) regimen has some features that distinguish it from others and is the only 8-week regimen approved for treatment-naive patients and patients experienced in regimens containing (peg)interferon, ribavirin, and/or sofosbuvir, without an HCV NS3/4A protease inhibitor or NS5A inhibitor (except those with genotype 3). This review aims to summarize the efficacy and safety of G/P in HCV-infected patients from clinic trials and real-world studies, including those who have historically been considered difficult to cure.

Glecaprevir-pibrentasvir to treat chronic hepatitis C virus infection in Asia: two multicentre, phase 3 studies- a randomised, double-blind study (VOYAGE-1) and an open-label, single-arm study (VOYAGE-2). Lancet Gastroenterol Hepatol. 2020;5:839-849. [PMID: 32682494 DOI: 10.1016/s2468-1253(20)30086-8]

BACKGROUND

Glecaprevir-pibrentasvir results in high rates of sustained virological response in patients with chronic hepatitis C virus (HCV) genotype 1-6 infection. Data for glecaprevir-pibrentasvir in non-Japanese Asian patients have been minimal. The aim of these studies was to assess the efficacy and safety of glecaprevir-pibrentasvir in treatment-naive and treatment-experienced Asian patients with chronic HCV genotype 1-6 infection without cirrhosis (VOYAGE-1) and with compensated cirrhosis (VOYAGE-2).

METHODS

We did two phase 3 studies in treatment-naive and treatment-experienced patients with chronic HCV genotype 1-6 infection. VOYAGE-1 was a randomised, double-blind, placebo-controlled study that recruited patients without cirrhosis at 47 sites across China, South Korea, and Singapore. Randomisation was 2:1 with a fixed block size of three and stratified by geographical region and HCV genotype. Investigators, study site personnel, the study sponsor, and patients were masked to treatment allocation. VOYAGE-2 was a single-arm, open-label study that recruited patients with compensated cirrhosis at 34 sites across China and South Korea. Glecaprevir (300 mg) and pibrentasvir (120 mg) or placebo (VOYAGE-1, 2:1 ratio), administered as three tablets daily, was given for 8 weeks in patients without cirrhosis and for 12 weeks in those with cirrhosis (and for 16 weeks in treatment-experienced patients with genotype 3). The primary efficacy endpoint was the proportion of patients with a sustained virological response, defined as HCV RNA below the lower limit of quantification 12 weeks after the last dose of glecaprevir-pibrentasvir. We analysed efficacy and safety in all patients who received at least one dose of the study drug. These trials are registered with ClinicalTrials.gov, NCT03222583 (VOYAGE-1) and NCT03235349 (VOYAGE-2); both trials have been completed. This Article reports the results of the primary analysis for each study, undertaken when all patients who received glecaprevir-pibrentasvir (during the double-blind period in VOYAGE-1) had been followed up for 12 weeks following their last dose of study drug. Data from the double-blind period for placebo patients in VOYAGE-1 are also summarised.

FINDINGS

Between Oct 4, 2017, and April 20, 2018, 546 patients with chronic HCV without cirrhosis were randomly assigned to treatment (363 to glecaprevir-pibrentasvir, 183 to placebo) in VOYAGE-1. One patient withdrew consent and did not receive treatment with glecaprevir-pibrentasvir. 352 of 362 patients who received glecaprevir-pibrentasvir achieved SVR12 (97·2% [95% CI 95·5-98·9]). Of 160 patients with compensated cirrhosis who were enrolled in VOYAGE-2 between Sept 29, 2017, and June 14, 2018, 159 of 160 achieved SVR12 (99·4%, 95% CI 98·2-100·0). 20 patients with HCV genotype 3b across both trials received glecaprevir-pibrentasvir; six of these patients were among the 11 patients who did not achieve SVR12. Upper respiratory tract infection was the most common adverse event (35 [10%] of 362 receiving glecaprevir-pibrentasvir and 18 [10%] of 183 receiving placebo in VOYAGE-1; 19 [12%] of 160 in VOYAGE-2). For patients receiving glecaprevir-pibrentasvir, serious adverse events occurred in three (<1%) of 362 patients in VOYAGE-1 and five (3%) of 160 patients in VOYAGE-2. Grade 3-4 adverse events in patients receiving glecaprevir-pibrentasvir occurred in five (1%) of 362 patients in VOYAGE-1 and six (4%) of 160 patients in VOYAGE-2; each type of event was experienced by at most one patient within a study. One patient with cirrhosis discontinued study drug because of an adverse event.

INTERPRETATION

Glecaprevir-pibrentasvir showed high efficacy and an acceptable safety profile in these studies although responses were less common in the few patients with HCV genotype 3b. The results support the use of glecaprevir-pibrentasvir in these Asian populations.

FUNDING

AbbVie.

A Thorough QT Study of the Combination Glecaprevir + Pibrentasvir on Cardiac Repolarization in Healthy Subjects

PURPOSE

Fixed-dose combination glecaprevir (GLE) 300 mg + pibrentasvir (PIB) 120 mg is an orally administered once daily antiviral regimen approved for the treatment of hepatitis C virus (HCV) infection. The objective of this study was to evaluate the potential for cardiac repolarization following GLE + PIB administration in healthy adults.

METHODS

This placebo- and active-controlled, randomized, single-dose, 4-period, 4-sequence crossover study enrolled 48 healthy subjects. The doses of GLE 400 mg + PIB 120 mg were selected to provide exposures comparable to those with the doses that are therapeutic in the HCV-infected population, GLE 300 mg + PIB 120 mg. The doses of GLE 600 mg + PIB 240 mg were selected to provide supratherapeutic exposures without exceeding the exposures of the GLE + PIB maximal tolerated doses. Moxifloxacin 400 mg (active control/open label) was used for confirming the sensitivity of the ECG assay in detecting QTc prolongation. Time-matched plasma concentrations and triplicate ECGs were obtained on treatment days -1 and 1. The primary end point was time-matched, placebo-corrected, baseline-adjusted Fridericia-corrected QT interval (ΔΔQTcF). Pharmacokinetic-pharmacodynamic analyses characterized the relationship between GLE and PIB plasma concentrations and ΔΔQTcF using a linear regression model and linear mixed-effects model. Findings from categorical analyses of ECG-interval data were also summarized. Tolerability was evaluated through adverse-events monitoring, physical examination including vital sign measurements, ECGs, and laboratory tests.

FINDINGS

A total of 48 subjects (22 women [46%], 26 men [54%]), were enrolled in the study, and 47 subjects completed all 4 periods. None of the subjects had a change from baseline in QTcF interval of >30 msec or an absolute QTcF interval of >450 msec. Peak ΔΔQTcF values observed at 5 h postdose (T_max) were 2.9 msec (upper 95% confidence limit, 4.9 msec) with the therapeutic dose and 3.1 msec (upper 95% confidence limit, 5.1 msec) with the supratherapeutic dose, with both upper 95% confidence limits well below the 10-msec threshold. Assay sensitivity was confirmed by peak ΔΔQTcF in the positive control (12.8 ms at 2 h postdose). No statistically significant GLE or PIB concentration-dependent effects on ΔΔQTcF were observed. Headache and skin irritation from ECG electrodes were the most commonly reported AEs. No clinically significant vital sign measurements, ECG findings, or laboratory measurements were observed. There were no patterns of T- and U-wave morphologic abnormalities.

IMPLICATIONS

The fixed-dose combination regimen of GLE/PIB does not prolong the QTc interval. ClinicalTrials.gov identifier.

Glecaprevir/pibrentasvir for patients with chronic hepatitis C virus infection: Real-world effectiveness and safety in Taiwan

BACKGROUND & AIMS

Large-scale data regarding the real-world effectiveness and safety of glecaprevir/pibrentasvir (GLE/PIB) for patients with chronic hepatitis C virus (HCV) infection were limited in East Asia. We aimed to evaluate the clinical performance of GLE/PIB in different HCV populations in Taiwan.

METHODS

A total of 658 chronic HCV patients with compensated liver diseases receiving GLE/PIB for 8 (n = 549), 12 (n = 103) or 16 (n = 6) weeks were retrospectively enrolled. The effectiveness was determined by sustained virologic response at off-therapy 12 weeks (SVR₁₂ ). Patient characteristics potentially related to SVR₁₂ and the safety profiles were also assessed.

RESULTS

By evaluable population (EP) and per-protocol (PP) analyses, the overall SVR₁₂ rate was 98.2% (95% confidence interval (CI): 96.8%-99.0%) and 99.4% (95% CI: 98.4%-99.8%). The SVR₁₂ rates were 98.9% (95% CI: 97.6%-99.5%), 94.2% (95% CI: 87.9%-97.3%) and 100% (95% CI: 60.1%-100%) in patients receiving 8, 12 and 16 weeks of treatment respectively. A total of 656 (99.7%) patients completed the scheduled treatment. The SVR₁₂ rates were comparable regardless of baseline characteristics or week 4 viral decline. Twenty (3.0%) patients had serious adverse events (AEs), but none were not related to GLE/PIB. The two most common AEs were pruritus (7.8%) and fatigue (5.5%). Two (0.3%) and no patients had ≥3-fold upper limit of normal (ULN) for total bilirubin and alanine aminotransferase (ALT) levels.

CONCLUSIONS

GLE/PIB for 8-16 weeks is effective and well-tolerated for patients with chronic HCV infection in Taiwan.

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.

A novel, potent, and orally bioavailable thiazole HCV NS5A inhibitor for the treatment of hepatitis C virus

A medicinal chemistry program based on the small-molecule HCV NS5A inhibitor daclatasvir has led to the discovery of dimeric phenylthiazole compound 8, a novel and potent HCV NS5A inhibitor. The subsequent SAR studies and optimization revealed that the cycloalkyl amide derivatives 27a-29a exhibited superior potency against GT1b with GT1b EC₅₀ values at picomolar concentration. Interestingly, high diastereospecificity for HCV inhibition was observed in this class with the (1R,2S,1'R,2'S) diastereomer displaying the highest GT1b inhibitory activity. The best inhibitor 27a was found to be 3-fold more potent (GT1b EC₅₀ = 0.003 nM) than daclatasvir (GT1b EC₅₀ = 0.009 nM) against GT1b, and no detectable in vitro cytotoxicity was observed (CC₅₀ > 50 μM). Pharmacokinetic studies demonstrated that compound 27a had an excellent pharmacokinetic profiles with a superior oral exposure and desired bioavailability after oral administration in both rats and dogs, and therefore it was selected as a developmental candidate for the treatment of HCV infection.

Glecaprevir/pibrentasvir for the treatment of chronic hepatitis C virus infection

In recent years, management of chronic hepatitis C virus (HCV) infection has been revolutionized by the availability of oral direct-acting antivirals (DAAs), which have significantly better efficacy and safety profiles than interferon-containing regimens. Simple, short-duration DAA therapies will facilitate expansion of HCV treatment to nonspecialist providers, which will be vital to achieve the WHO target of eliminating chronic HCV as a major public health threat by 2030. Coformulated glecaprevir/pibrentasvir is the only 8-week, pan-genotypic, 2-DAA regimen recommended by international guidelines as a first-line regimen in treatment-naive, noncirrhotic HCV genotype 1-6 patients. This review provides a comprehensive summary of the pharmacodynamic and pharmacokinetic parameters, efficacy, safety and place in the HCV treatment paradigm for glecaprevir/pibrentasvir.

An update on the toxicological considerations for protease inhibitors used for hepatitis C infection

INTRODUCTION

Hepatitis C virus protease inhibitors (PIs) are important components of many direct acting antiviral regimens. Many clinical trials and real-world studies have described the safety data for individual PIs. We aimed to review the safety of both the first and second generation PIs in patients with chronic hepatitis C (CHC). Areas covered: The unique pharmacokinetic properties of PIs partly explain their toxicities. Second generation PIs, when used without interferon and ribavirin, are well-tolerated. Use of PIs in renal impaired patients or those on dialysis appears to be safe. Decompensated cirrhosis is a contraindication for PIs use due to increased drug exposure and risk of liver decompensation. Drug-drug interactions are common and should be always monitored; some drugs should not be co-administered with PIs. In patients with co-infected hepatitis B virus, reactivation after DAA (whether PI-containing or not) is a concern. Expert opinion: Second generation PIs are key players in the current DAA era. Post-marketing surveillance is essential to monitor unknown adverse events and drug-drug interactions. Non-PI based DAA should be used in decompensated liver disease. The use of these drugs should also be explored in the paediatric population.

Highlights of the Structure-Activity Relationships of Benzimidazole Linked Pyrrolidines Leading to the Discovery of the Hepatitis C Virus NS5A Inhibitor Pibrentasvir (ABT-530)

Curative interferon and ribavirin sparing treatments for hepatitis C virus (HCV)-infected patients require a combination of mechanistically orthogonal direct acting antivirals. A shared component of these treatments is usually an HCV NS5A inhibitor. First generation FDA approved treatments, including the component NS5A inhibitors, do not exhibit equivalent efficacy against HCV virus genotypes 1-6. In particular, these first generation NS5A inhibitors tend to select for viral drug resistance. Ombitasvir is a first generation HCV NS5A inhibitor included as a key component of Viekira Pak for the treatment of patients with HCV genotype 1 infection. Since the launch of next generation HCV treatments, functional cure for genotype 1-6 HCV infections has been achieved, as well as shortened treatment duration across a wider spectrum of genotypes. In this paper, we show how we have modified the anchor, linker, and end-cap architecture of our NS5A inhibitor design template to discover a next generation NS5A inhibitor pibrentasvir (ABT-530), which exhibits potent inhibition of the replication of wild-type genotype 1-6 HCV replicons, as well as improved activity against replicon variants demonstrating resistance against first generation NS5A inhibitors.

Formulary Drug Reviews: Glecaprevir/Pibrentasvir

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