Efficacy and Safety of Glecaprevir/Pibrentasvir for Chronic Hepatitis C Patients: A Systematic Review and Meta-analysis.

Background and Aims: Glecaprevir/pibrentasvir is a pangenotypic regimen recently approved for the treatment of chronic hepatitis C virus (HCV) infection. The objective of the present review was to summarize the findings from clinical trials to understand how patient-related factors influence glecaprevir/pibrentasvir efficacy (sustained virologic response rates at 12 weeks' after treatment [referred to as SVR12]) and safety. Methods: Data from 21 phase III clinical trials were analyzed. Results: The integrated efficacy analysis included 4,817 patients. Findings showed 97.5% of all included patients with chronic HCV achieved SVR12 in the intention-to-treat population. SVR12 rate was >95% across subgroups of interest. The integrated safety analysis included 4,015 patients. Findings showed that 64.1% of patients reported an adverse event, and <0.1% of patients reported a serious adverse event related to glecaprevir/pibrentasvir. Conclusions: These results indicate that the 8- or 12-week glecaprevir/pibrentasvir treatment is effective for patients infected with HCV genotypes 1-6 without or with compensated cirrhosis, with good safety profiles, irrespective of treatment-experience. Glecaprevir/pibrentasvir is a good option for patients with human immunodeficiency virus/HCV coinfection and comorbid HCV and severe renal impairment.

Glecaprevir/pibrentasvir in patients with chronic HCV and recent drug use: An integrated analysis of 7 phase III studies.

BACKGROUND: Injection drug use is the primary mode of transmission for hepatitis C virus (HCV), and treatment guidelines recommend treating HCV-infected people who use drugs; however, concerns about adherence, effectiveness, and reinfection have impeded treatment uptake. METHODS: Data were pooled from seven phase III trials that evaluated the efficacy and safety of 8 or 12 weeks of glecaprevir/pibrentasvir (G/P) in patients chronically infected with HCV genotypes 1-6. Patients had compensated liver disease, with or without cirrhosis, and were HCV treatment-naïve or -experienced with interferon or pegylated interferon ± ribavirin, or sofosbuvir plus ribavirin ± pegylated interferon. Patients were grouped into recent drug users (injection drug use ≤12 months before screening, positive urine drug screen [UDS], and/or drug-related adverse event), former drug users (>12 months before screening and negative UDS), or non-drug users. Assessments included sustained virologic response at 12 weeks posttreatment (SVR12), treatment adherence, and safety. RESULTS: Among 1819 patients, 5%, 34%, and 61% were recent, former, and non-drug users, respectively. Treatment adherence and completion were high (≥96%) regardless of drug use status. SVR12 was achieved by 93% (n/N = 91/98), 97% (n/N = 591/610), and >99% (n/N = 1106/1111) of recent, former, and non-drug users, respectively (intention-to-treat analysis). The overall rates of virologic failure were ≤1.5% across all three subpopulations, with no HCV reinfections among recent drug users. Drug-related serious adverse events and adverse events leading to treatment discontinuation were experienced by ≤1% of patients. CONCLUSIONS: G/P is a well-tolerated and efficacious pangenotypic regimen for chronic HCV-infected people with recent or active drug use.

Resistance Analysis of a 3-Day Monotherapy Study with Glecaprevir or Pibrentasvir in Patients with Chronic Hepatitis C Virus Genotype 1 Infection.

Glecaprevir (an NS3/4A protease inhibitor) and pibrentasvir (an NS5A inhibitor) are potent and pangenotypic hepatitis C virus (HCV) direct-acting antivirals. This report describes the baseline polymorphisms and treatment-emergent substitutions in NS3 or NS5A detected in samples from HCV genotype 1-infected patients receiving 3-day monotherapy of glecaprevir or pibrentasvir, respectively. None of the NS3 polymorphisms detected in the 47 baseline samples collected prior to glecaprevir monotherapy conferred reduced susceptibility to glecaprevir. The NS3 A156T substitution, which conferred resistance to glecaprevir but had low replication efficiency, emerged in one genotype 1a-infected patient among the 35 patients with available post-baseline sequence data. Baseline NS5A polymorphisms were detected in 12 of 40 patients prior to pibrentasvir monotherapy; most polymorphisms were single-position NS5A amino acid substitutions that did not confer resistance to pibrentasvir. Among the 19 patients with available post-baseline NS5A sequence data, 3 had treatment-emergent NS5A substitutions during pibrentasvir monotherapy. All treatment-emergent NS5A substitutions were linked multiple-position, almost exclusively double-position, substitutions that conferred resistance to pibrentasvir. Replicons engineered with these double-position substitutions had low replication efficiency. In conclusion, resistance-conferring substitutions emerged in a small number of genotype 1-infected patients during glecaprevir or pibrentasvir monotherapy; unlike other NS5A inhibitors, pibrentasvir did not select single-position NS5A substitutions during monotherapy.

Glecaprevir/pibrentasvir expands reach while reducing cost and duration of hepatitis C virus therapy.

Hepatitis C virus (HCV) treatments have dramatically progressed from poorly tolerated, moderately successful interferon-based therapies to highly effective all-oral interferon-free regimens. While sustained virologic responses have significantly improved with fixed-dose combinations (FDC) of these direct-acting antivirals (DAA), cost remains high and certain populations of patients remain difficult to treat. Glecaprevir (GLE, an NS3/4A protease inhibitor) and pibrentasvir (PIB, NS5A inhibitor) were recently approved as a FDC therapy for HCV, and have expanded reach, reduced cost, and in certain populations, reduced HCV treatment duration. GLE/PIB is effective across all genotypes, and has been shown to be effective in HIV-infected patients, patients with chronic kidney disease, and Child-Pugh A-compensated cirrhosis. GLE/PIB is also effective for a shortened duration of 8 weeks in treatment-naive non-cirrhotic patients.

In Vitro Antiviral Activity and Resistance Profile of the Next-Generation Hepatitis C Virus NS3/4A Protease Inhibitor Glecaprevir.

Glecaprevir (formerly ABT-493) is a novel hepatitis C virus (HCV) NS3/4A protease inhibitor (PI) with pangenotypic activity. It inhibited the enzymatic activity of purified NS3/4A proteases from HCV genotypes 1 to 6 in vitro (half-maximal [50%] inhibitory concentration = 3.5 to 11.3 nM) and the replication of stable HCV subgenomic replicons containing proteases from genotypes 1 to 6 (50% effective concentration [EC50] = 0.21 to 4.6 nM). Glecaprevir had a median EC50 of 0.30 nM (range, 0.05 to 3.8 nM) for HCV replicons containing proteases from 40 samples from patients infected with HCV genotypes 1 to 5. Importantly, glecaprevir was active against the protease from genotype 3, the most-difficult-to-treat HCV genotype, in both enzymatic and replicon assays demonstrating comparable activity against the other HCV genotypes. In drug-resistant colony selection studies, glecaprevir generally selected substitutions at NS3 amino acid position A156 in replicons containing proteases from genotypes 1a, 1b, 2a, 2b, 3a, and 4a and substitutions at position D/Q168 in replicons containing proteases from genotypes 3a, 5a, and 6a. Although the substitutions A156T and A156V in NS3 of genotype 1 reduced susceptibility to glecaprevir, replicons with these substitutions demonstrated a low replication efficiency in vitro Glecaprevir is active against HCV with most of the common NS3 amino acid substitutions that are associated with reduced susceptibility to other currently approved HCV PIs, including those at positions 155 and 168. Combination of glecaprevir with HCV inhibitors with other mechanisms of action resulted in additive or synergistic antiviral activity. In summary, glecaprevir is a next-generation HCV PI with potent pangenotypic activity and a high barrier to the development of resistance.

Glecaprevir and pibrentasvir yield high response rates in patients with HCV genotype 1-6 without cirrhosis.

BACKGROUND & AIMS: Hepatitis C virus (HCV) therapy that is highly efficacious, pangenotypic, with a high barrier to resistance and short treatment duration is desirable. The efficacy and safety of 8- and 12-week treatments with glecaprevir (ABT-493; NS3/4A protease inhibitor) and pibrentasvir (ABT-530; NS5A inhibitor) were evaluated in non-cirrhotic patients with chronic HCV genotype 1-6 infection. METHODS: SURVEYOR-I and SURVEYOR-II were phase II, open-label, multicenter, dose-ranging trials including patients with chronic HCV genotype 1-6 infection who were either previously untreated or treated with pegylated interferon plus ribavirin. Patients received once-daily glecaprevir plus pibrentasvir at varying doses with or without ribavirin for 8 or 12weeks. The primary efficacy endpoint was the percentage of patients with a sustained virologic response at post-treatment week 12 (SVR12). RESULTS: Of the 449 patients who received varying doses of glecaprevir plus pibrentasvir, 25%, 29%, 39%, and 8% had HCV genotype 1, 2, 3, and 4-6 infection, respectively. Twelve-week treatment achieved SVR12 in 97-100%, 96-100%, 83-94%, and 100% in genotypes 1, 2, 3, and 4-6, respectively. Eight-week treatment with 300mg glecaprevir plus 120mg pibrentasvir in genotype 1-, 2-, or 3-infected patients yielded 97-98% SVR12 with no virologic failures. Three (0.7%) patients discontinued treatment due to adverse events; most events were mild (grade 1) in severity. No post-nadir alanine aminotransferase elevations were observed. CONCLUSIONS: Glecaprevir plus pibrentasvir was well tolerated and achieved high sustained virologic response rates in HCV genotypes 1-6-infected patients without cirrhosis following 8- or 12-week treatment durations. LAY SUMMARY: The combination of direct-acting antivirals glecaprevir and pibrentasvir comprise a once-daily, all-oral, pangenotypic treatment for HCV genotype 1-6 infection. This article describes results from two phase II trials investigating a range of doses at treatment durations of 8 or 12weeks in 449 patients without cirrhosis. Efficacy of the optimal dose, as determined by rates of sustained virologic response at post-treatment week 12, ranged from 92%-100%; treatment was well tolerated and significant laboratory abnormalities were rare. CLINICAL TRIAL REGISTRATION: clinicaltrials.gov Identifiers: NCT02243280 and NCT02243293. http://www.clinicaltrials.gov/show/NCT02243280, http://www.clinicaltrials.gov/show/NCT01939197.