Validated LC/MS method for simultaneous determination of elbasvir and grazoprevir in human plasma.

A sensitive and accurate LC/MS method for the determination of elbasvir (ELB) and grazoprevir (GZP) in human plasma was established using daclatasvir (DCT) as an internal standard. The analytes were separated on a Waters Spherisorb phenyl column (150mm×4.6mm ID, 5µm particle size) maintained at 40°C±2°C. Gradient elution, at a flow rate of 0.8mLmin-1, was used. The mobile phase consists of 90% of acetonitrile mixed to 10% of a 5mM ammonium formate buffer (+0.1% v/v of trimethylamine, pH was adjusted to 3.2 by formic acid) as phase A and 10% of acetonitrile mixed to 90% of the same buffer as phase B. Liquid-liquid extraction with ethyl acetate solvent was used to recuperate compounds from plasma. The method was validated over a concentration range of 2 and 100ng/mL for GZP and between 1 and 50ng/mL for ELB. The intra- and inter-day precision and accuracy of the quality control samples at low, medium, and high concentration levels exhibited relative standard deviations (RSD)<15%, and the accuracy values ranged from 94.2 to 107.8%. The robustness of the method was established using a two-level full factorial design.

High real-world effectiveness of 12-week elbasvir/grazoprevir without resistance testing in the treatment of patients with HCV genotype 1a infection in Norway.

BACKGROUND AND AIMS: The recommended treatment duration of hepatitis C virus (HCV) genotype 1a (GT1a) infection with elbasvir/grazoprevir (EBR/GZR) in the presence of a high baseline viral load and resistance associated substitutions (RAS) is 16 weeks with ribavirin added. The objective of this study was to evaluate the real-world effectiveness of 12 weeks of EBR/GZR without ribavirin and regardless of baseline viral load and RAS testing. METHOD: This retrospective, observational cohort study was performed at five Norwegian hospitals that did not systematically utilize RAS testing. All adult patients with chronic HCV GT1a and compensated liver disease who had received 12 weeks of EBR/GZR without ribavirin and baseline RAS testing, were included. The primary endpoint was sustained virologic response at week 12 (SVR12), or if not available, at week 4 (SVR4). RESULTS: We included 433 patients and attained SVR data on 388. The mean age was 45.7 years (22-73 years). 67.2% were male. HIV co-infection was present in 3.8% (16/424) and cirrhosis in 4% (17/424). The viral load was >800 000 IU/mL in 55.0% (235/427) of patients. Overall SVR was achieved in 97.2% (377/388). SVR was achieved in 98.3% (169/172) of those with viral load ≤800 000 IU/mL and in 96.2% (202/210) of those with viral load >800 000 IU/mL. CONCLUSION: We observed high SVR rates among patients with HCV GT1a infection treated with EBR/GZR for 12 weeks without ribavirin, with no regard to baseline viral load and no RAS testing.

Safety and efficacy of grazoprevir/elbasvir in the treatment of acute hepatitis C in hemodialysis patients.

Treatment of hepatitis C virus (HCV) infection with direct-acting antiviral agents (DAAs) in hemodialysis patients requires extensive consideration. At present, studies regarding DAAs for acute HCV infection in such patients are limited. The present study aims to evaluate the efficacy and safety of grazoprevir (GZR) plus elbasvir (EBR) treatment in acute hepatitis C (AHC) patients undergoing hemodialysis. Patients undergoing hemodialysis who had a nosocomial acute HCV infection were enrolled. All patients received GZR 100 mg/EBR 50 mg once daily for 12 weeks and were followed up for 12 weeks. Serum alanine transaminase (ALT), aspartate aminotransferase (AST), total bilirubin (TBIL), and HCV RNA levels were monitored during treatment and follow-up periods. Sustained virologic response at 12 weeks after treatment cessation and treatment-emergent adverse events (AEs) were assessed. A total of 68 AHC patients were enrolled. All patients were infected with HCV genotype 1b and achieved SVR12. Decreasing ALT, AST, and TBIL were observed over time in the first 4 weeks and became steady thereafter. Forty-eight (70.59%) patients reported at least one AEs. The most common AEs were fatigue, headache, and nausea. Two AHC patients discontinued treatment due to serious but drug-unrelated AEs. In conclusion, GZR/EBR has a high efficacy and safety profile in hemodialysis-dependent patients with genotype 1b AHC.

Drug repositioning to target NSP15 protein on SARS-CoV-2 as possible COVID-19 treatment.

SARS-CoV and SARS-CoV-2 belong to the subfamily Coronaviridae and infect humans, they are constituted by four structural proteins: Spike glycoprotein (S), membrane (M), envelope (E) and nucleocapsid (N), and nonstructural proteins, such as Nsp15 protein which is exclusively present on nidoviruses and is absent in other RNA viruses, making it an ideal target in the field of drug design. A virtual screening strategy to search for potential drugs was proposed, using molecular docking to explore a library of approved drugs available in the DrugBank database in order to identify possible NSP15 inhibitors to treat Covid19 disease. We found from the docking analysis that the antiviral drugs: Paritaprevir and Elbasvir, currently both approved for hepatitis C treatment which showed some of the lowest free binding energy values were considered as repositioning drugs to combat SARS-CoV-2. Furthermore, molecular dynamics simulations of the Apo and Holo-Nsp15 systems were performed in order to get insights about the stability of these protein-ligand complexes.

Impact of recent drug use on the efficacy of elbasvir/grazoprevir for HCV-infected people on opioid agonist therapy.

Elbasvir/grazoprevir (EBR/GZR) use in drug users on opiate agonist therapy (OAT) is supported by the C-EDGE Co-STAR trial. SVR rates in this study were within those found in the rest of patients included by the EBR/GZR development programme. In clinical practice, however, efficacy could theoretically be lower. Thus, we aimed at evaluating the SVR rates of EBR/GZR among people who injected drugs (PWID) with and without OAT in clinical practice. Patients starting EBR/GZR included in the HEPAVIR-DAA (NCT02057003), recruiting HIV/HCV-coinfected patients or the GEHEP-MONO (NCT02333292), including HCV-monoinfected individuals, prospective cohorts were analysed. Overall SVR12 (ITT), discontinuations due to adverse effects and drop-outs were evaluated. The same analysis was carried out for PWID with and without OAT. 336 patients had started EBR/GZR and reached the SVR12 evaluation date. 318 [95%, 95% confidence interval (95% CI): 92%-98%] patients achieved SVR12. SVR12 was 97% (95% CI: 93%-99%, n/N = 141/145) among people who never used injecting drugs, 94% (95% CI: 88%-97%, n/N = 117/125) among PWIDs without OAT and 91% (95% CI: 81%-97%, n/N = 60/66) among PWIDs with OAT (p = 0.134). Five (1.5%) patients showed relapses, and two (0.6%) individuals showed viral breakthrough. The SVR12 rate for recent drug users was 69% (n/N = 18/26) compared with 97% (n/N = 276/284) for individuals without recent drug use (in the prior year) (p < 0.001). Among recent drug users, three (12%) showed relapses, and five (19%) were lost-to-follow-up. The SVR rates achieved with EBR/GZR were high in real-world conditions of use. However, PWID with recent drug use reach suboptimal response rates with EBR/GZR.

Cost-Utility of All-Oral Direct-Acting Antiviral Regimens for the Treatment of Genotype 1 Chronic Hepatitis C Virus-Infected Patients in Hong Kong.

BACKGROUND: Direct-acting antivirals (DAAs) are entering the hepatitis C virus (HCV) treatment landscape in Hong Kong, prompting the need for cost-effectiveness evaluations of these interventions to enable optimal use of healthcare resources. AIMS: This study aimed to compare the cost-effectiveness of DAAs to standard-of-care pegylated interferon plus ribavirin (RBV) in treatment-naïve patients without significant liver fibrosis and to compare different DAAs in patients who are treatment-experienced and/or have advanced liver disease. METHODS: A Markov model was constructed to evaluate cost-effectiveness over a lifetime time horizon from the payer perspective. The target population was treatment-naïve and treatment-experienced HCV genotype 1 patients, stratified by degree of liver fibrosis. The model consists of 16 health states encompassing METAVIR fibrosis score (F0-F4), treatment success or failure, decompensated cirrhosis, hepatocellular carcinoma, liver transplant, and liver-related death. The proportions of patients achieving sustained virologic response were obtained from clinical trials. Other inputs were obtained from published and local data. The primary outcome was incremental cost-utility ratio for each DAA versus pegylated interferon + ribavirin and among different DAAs. RESULTS: In treatment-naïve F0-2 HCV patients, all DAAs were cost-effective in genotype 1a and daclatasvir + asunaprevir, elbasvir/grazoprevir, ledipasvir/sofosbuvir, and glecaprevir/pibrentasvir were cost-effective compared to pegylated interferon + ribavirin in genotype 1b. In genotypes 1a and 1b, treatment-experienced patients, and F3-4 patients, elbasvir/grazoprevir was the least costly DAA and economically dominant over most other DAAs. CONCLUSIONS: DAAs can be a cost-effective option for the treatment of genotype 1 HCV patients in Hong Kong, and elbasvir/grazoprevir is cost-effective.

Efficacy of Elbasvir/Grazoprevir in Early Chronic G1/G4 Hepatitis C infection in HIV/HCV co-infected patients with mild fibrosis.

BACKGROUND: Acute hepatitis C virus (AHC) infection is increasingly common among HIV+ men who have sex with men (MSM). Until 2017, the guidelines recommended therapy with pegylated-interferon plus ribavirin with a mild sustained virological response (SVR). This prompted many patients to reject that treatment, at that time, waiting to be treated with better and safer options with new Direct-Acting-Antivirals (DAA). OBJECTIVES: Assess the efficacy and safety of Elbasvir/Grazoprevir to treat recent chronic hepatitis C infection, genotype 1 or 4, in HIV+ MSM patients. METHODS: Prospective, open-labeled, two center, pilot study. SVR is analyzed for treatment with Elbasvir/Grazoprevir (8 weeks in GT1b or 12 in GT1a or GT4) in patients with a recent chronic HCV infection, defined as HCV infection lasting less than 4 years and mild liver fibrosis (liver stiffness <8kPa). RESULTS: Forty-eight patients were included (May 2017-March 2018): 2 GT1b, 24 GT1a and 22 GT4. HCV-RNA>800000UI in 63% and medium liver stiffness 4.9kPa. The SVR was 98%, one patient failed due to poor adherence. 67% of patients had adverse effects, but only 16% treatment related. The most frequent side effects were gastrointestinal (19%), related with the central nervous system (18%), respiratory (16%) and systemic symptoms (15%). During one year of follow-up post-therapy, 4 AHC and 18 patients with sexually transmitted diseases (STD) were diagnosed. CONCLUSIONS: Treatment with Elbasvir/Grazoprevir in this scenario is highly effective and safe. Patients with risky sexual practices must remain linked to the medical care system to detect new STD and HCV reinfection.

Real-world experience of elbasvir/grazoprevir in Taiwan: This study was focused on liver and renal adverse effects.

Elbasvir/grazoprevir with or without ribavirin has excellent efficacy and safety for the treatment of hepatitis C virus (HCV) genotype 1 and 4 patients. The real-world experience has been reported but the detailed analysis of liver and renal adverse effects is lacking. This study evaluated the real-world experience relating to the effectiveness and liver/renal safety of elbasvir/grazoprevir in HCV genotype 1 patients with compensated liver disease. In the four medical centres of Chang Gung Medical System, 350 HCV genotype 1 patients with compensated liver disease who were treated with elbasvir/grazoprevir were enrolled. Clinical characteristics and laboratory data were collected. The effectiveness (sustained virologic response 12 weeks after end of treatment, SVR12) and safety were assessed. A consecutive series of 350 patients with a mean age of 68.8 ± 10.0 years old were enrolled. The majority were treatment-naïve (72.3%), genotype 1b (97.7%) and advanced fibrosis/cirrhosis (94.3%). Seventy-nine (22.6%) had hepatocellular carcinoma and 23 (6.6%) had coinfection with hepatitis B. The effectiveness of SVR12 was 94.6% (95% CI: 92.2%-97.0%) in the full analysis set and 99.1% (95% CI: 98.1%-100.1%) in the per-protocol set. There were two relapses and one nonresponder. Seven (2.0%) patients had adverse events resulting in premature discontinuation of treatment. Five of them were considered drug-related. One was due to autoimmune hepatitis. Contrary to previous reports, around 49% of ALT elevation was observed after 8 weeks, and in two patients was due to hepatitis B flares. As to the renal function during the course of therapy, a minor deterioration of eGFR was observed in patients with baseline eGFR ≥60 mL/min/1.73 m2 , but not in those with baseline eGFR <60, <60-30 or <30 mL/min/1.73 m2 . In this real-world data, elbasvir/grazoprevir was effective with few liver/renal adverse effects. One patient developed autoimmune hepatitis.

Safety and tolerability of elbasvir/grazoprevir in chronic hepatitis C virus therapy: Integrated analysis from clinical trials.

Direct-acting antiviral treatments for chronic hepatitis C virus (HCV) infection are generally safe; however, understanding the safety profile of each regimen is essential for their continued use. Safety data were pooled from 12 clinical trials of elbasvir/grazoprevir (EBR/GZR) that enrolled adult participants with HCV infection. Pooled analyses are presented for participants receiving EBR/GZR for 12 weeks and those receiving EBR/GZR plus ribavirin (RBV) for 16-18 weeks. Safety data are also presented for participants with comorbidities receiving EBR/GZR for 12 weeks in individual clinical trials (chronic kidney disease [CKD] stage 4/5, inherited blood disorders [IBLD] or receiving opioid agonist therapy [OAT]). Among 1743 participants receiving EBR/GZR for 12 weeks, 1068 (61.3%) reported ≥1 adverse event (AE) and 491 had AEs (28.2%) considered drug-related. The most frequent AEs were headache (10.6%), fatigue (8.7%), nasopharyngitis (5.8%), nausea (5.1%) and diarrhoea (5.0%). Serious AEs were reported by 37 participants (2.1%), and 12 (0.7%) discontinued treatment due to an AE. In populations with CKD 4/5 or IBLD or receiving OAT, safety was similar in participants receiving EBR/GZR for 12 weeks and those receiving placebo. Some AEs occurred at higher frequencies in participants receiving RBV compared with those receiving EBR/GZR alone: fatigue (32.7% vs 8.7%); headache (21.6% vs 10.6%); and nausea (15.8% vs 5.1%). Safety was similar in participants with and those without cirrhosis. Grade 3/4 alanine aminotransferase elevations were reported in 0.7% participants. EBR/GZR is a safe treatment option for individuals with HCV genotype (GT) 1 or GT4 infections, even those with challenging comorbidities such as CKD or IBLD and those receiving OAT.

The efficacy and safety of elbasvir/grazoprevir treatment in HCV genotype 1 patients in Taiwan.

BACKGROUND: Elbasvir/grazoprevir (EBR/GZR) is a new generation, fixed-dose, combination antiviral drug used in chronic hepatitis C virus (HCV) genotype (GT) 1 or 4 infection. Our study evaluates the clinical efficacy and safety of EBR/GZR after its launch in Taiwan. METHODS: This is a retrospective observational study. Patients who had received EBR/GZR for chronic HCV GT 1 between June 2017 and April 2018 were recruited. Patients' age, sex, HCV GT, changes in HCV RNA level before and after treatment, sustained virologic response 12 weeks (SVR12) after the cessation of drug administration, side effects, and interaction effects were used to evaluate the clinical efficacy and safety. RESULTS: A total of 149 patients were recruited. Of them, 145 (97.3%) had HCV GT 1b, and the rest had HCV GT 1a; most of the EBR/GZR-related side effects in this study were mild. Three participants were discontinued because their alanine transaminase levels were elevated to over 10 times the upper limit of normal. The therapeutic effect analyses revealed a rapid virologic response rate of 95.3% and an SVR12 rate of 98%. Subgroup analyses performed using SVR12 as the outcome variable revealed three demographic factors HCV GT 1, hepatocellular carcinoma medical history, and noncirrhosis plus HCV RNA level. CONCLUSIONS: This study confirmed that EBR/GZR is safe and effective for treating patients with HCV GT 1 and exhibited excellent overall clinical efficacy in Taiwan. The therapeutic effects are unrelated to factors such as sex, HCV RNA level before treatment, and history of liver cirrhosis.

Real-world experience with Grazoprevir/Elbasvir in the treatment of previously "difficult to treat" patients infected with hepatitis C virus genotype 1 and 4.

BACKGROUND AND AIM: Grazoprevir/elbasvir (GZR/EBR) was approved for the treatment of chronic hepatitis C virus (HCV) genotype 1 and 4 infected patients with or without compensated liver cirrhosis. The aim of this study was to assess GZR/EBR regimen in the real-world experience, particularly in previously "difficult-to-treat" patients with chronic kidney diseases, human immunodeficiency virus-coinfected, cirrhotics, and treatment-experienced. METHODS: The analysis included patients treated with GZR/EBR selected from 10 152 individuals from the EpiTer-2 database, large national real-world study evaluating antiviral treatment in 22 Polish hepatology centers between 2015 and 2018. Data were completed retrospectively and submitted online. RESULTS: A total of 1615 patients who started GZR/EBR therapy in 2017 and 2018 with a female predominance (54%) and median age of 54 years were analyzed. The majority were infected with GT1b (89%) and treatment naïve (81%). Liver cirrhosis was diagnosed in 19%, and 70% of patients had comorbidities, of which chronic renal disease was present in 7% and HIV-coinfection in 4%. Overall, a sustained virologic response (SVR) was achieved by 95% according to intent-to-treat (ITT) and 98% after exclusion of lost to follow up (modified ITT). No differences were found in cure rate between all included patients and subpopulations previously considered as difficult-to-treat. Majority of patients completed the treatment course as scheduled, adverse events were mostly mild and did not lead to therapy discontinuation. CONCLUSIONS: GZR/EBR treatment carried-out in patients infected with HCV genotype 1 and 4 demonstrated good tolerability and an excellent SVR rate with no effectiveness reduction in so called difficult-to-treat populations.

Elbasvir/grazoprevir treatment in an HCV-infected peritoneal dialysis patient.

Hepatitis C virus (HCV) infection is known to affect long-term patient survivals. Elbasvir/grazoprevir (EBR/GZR) has shown a high cure rate in hemodialysis patients with HCV infection. However, the combination is rarely used in peritoneal dialysis patients. Herein, we report a case of successful treatment with EBR/GZR in a peritoneal dialysis patient with HCV genotype 1 b infection. A 54-year-old woman on peritoneal dialysis（PD）with HCV genotype 1 b infection had been received EBR (100 mg) and GZR (50 mg) once daily for 12 weeks. Hepatitis C virus RNA was undetectable 4 weeks after the treatment. She achieved a sustained virological response at 12 weeks after the end of treatment. Only fatigue was reported as side effect during the treatment. Thus, elbasvir/grazoprevir was effective and safe in this PD patient with HCV genotype 1 b infection.

Limited drug-drug interaction of elbasvir/grazoprevir for chronic hepatitis C.

BACKGROUND/PURPOSE: The assessment of drug-drug interaction (DDI) is important not only for safety but also for maintaining the efficacy of direct acting antivirals in chronic hepatitis C (CHC). This study aims to evaluate DDI before and during elbasvir/grazoprevir (EBR/GZR) treatment. METHODS: CHC patients who treated with EBR/GZR in five hospitals were enrolled. The patients' demographic data, comorbidities, concomitant medications taken before and during EBR/GZR were recorded. DDI was evaluated using a tool from the HEP Drug Interactions (www.hep-druginteractions.org) website. In addition to the evaluation of DDI for EBR/GZR, the virtual DDI of ledipasvir/sofosbuvir (LDV/SOF), sofosbuvir/velpatasvir (SOF/VEL) and glecaprevir/pibrentasvir (GLE/PIB) were evaluated. Degrees of DDI were classified as "do not co-administer", "potential interaction", and "potentially weak interaction". RESULTS: A total of 460 patients were enrolled. At baseline, 80.1% of patients had one or more comorbidities and 72.8% took one or more medications. Cardiovascular diseases (43.9%), gastrointestinal diseases (37.4%), and metabolic diseases (36.7%) were the three most common comorbidities. The prevalence of DDI before EBR/GZR treatment was 12.8% (59 patients). Among the same population, the prevalence of virtual DDI of SOF/VEL, GLE/PIB, and LDV/SOF were 38.5% (179 patients), 48.8% (220 patients), and 57.0% (262 patients), respectively. During EBR/GZR treatment, 167 patients (36.3%) took newly prescribed medications. One patient (0.2%) and seven patients (1/5%) exhibited do-not-co-administer and potential interaction with EBR/GZR, respectively. CONCLUSION: DDI was limited in treatment with EBR/GZR. DDI can occur upon the administering of a new medication during antiviral treatment and attention should be paid to it. TRIAL REGISTRATION NUMBER: NCT03706222.

An Open-Label, Randomized, Active-Controlled Trial of 8 Versus 12 Weeks of Elbasvir/Grazoprevir for Treatment-Naive Patients With Chronic Hepatitis C Genotype 1b Infection and Mild Fibrosis (EGALITE Study): Impact of Baseline Viral Loads and NS5A Resistance-Associated Substitutions.

BACKGROUND: A 12-week grazoprevir/elbasvir regimen is highly effective against hepatitis C virus genotype 1 (HCV-1) infection. The efficacy of an 8-week regimen for treatment-naive HCV-1-infected patients with mild fibrosis has not been determined. METHODS: Treatment-naive HCV-1b-infected patients with mild fibrosis were randomly assigned to receive 8 (n = 41) or 12 (n = 41) weeks of grazoprevir/elbasvir therapy. The primary end point was a sustained virologic response, defined as an HCV RNA level of < 12 IU/mL, at posttreatment week 12 (SVR12). RESULTS: SVR12 was achieved by 87.8% of patients (36 of 41) in the 8-week arm and 100% (41 of 41) in the 8-week arm of the full-analysis population and by 90.0% (36 of 40) and 100% (41 of 41), respectively, in the per-protocol population (all P = .055). In the 8-week arm, a significantly lower SVR12 rate was observed among patients with a high HCV-1b load, defined as ≥1 500 000 IU/mL (79% vs 100%; P = .042), and among those with a baseline Y93H resistance-associated substitution (RAS) frequency of >15% in HCV nonstructural protein 5A (NS5A; 40.0% vs 97.1%; P = .004). Between-group analysis demonstrated that, among patient with a high HCV-1b load and a baseline Y93H RAS frequency of >15%, those in the 8-week arm had a substantially lower SVR12 rate than those in the 12-week arm (40.0% vs 100.0%). All 4 HCV-1b relapses had a Y93H RAS frequency of >99% at posttreatment week 12. CONCLUSIONS: Twelve weeks of grazoprevir/elbasvir therapy is highly effective for treatment-naive patients with mild fibrosis. A truncated, 8-week grazoprevir/elbasvir regimen might be applied for those with low viral loads or without a significant NS5A RAS frequency. CLINICAL TRIALS REGISTRATION: NCT03186365.

Pharmacokinetic Interactions between the Hepatitis C Virus Inhibitors Elbasvir and Grazoprevir and HIV Protease Inhibitors Ritonavir, Atazanavir, Lopinavir, and Darunavir in Healthy Volunteers.

The combination of the hepatitis C virus (HCV) nonstructural protein 5A (NS5A) inhibitor elbasvir and the NS3/4A protease inhibitor grazoprevir is a potent, once-daily therapy indicated for the treatment of chronic HCV infection in individuals coinfected with human immunodeficiency virus (HIV). We explored the pharmacokinetic interactions of elbasvir and grazoprevir with ritonavir and ritonavir-boosted HIV protease inhibitors in three phase 1 trials. Drug-drug interaction trials with healthy participants were conducted to evaluate the effect of ritonavir on the pharmacokinetics of grazoprevir (n = 10) and the potential two-way pharmacokinetic interactions of elbasvir (n = 30) or grazoprevir (n = 39) when coadministered with ritonavir-boosted atazanavir, lopinavir, or darunavir. Coadministration of ritonavir with grazoprevir increased grazoprevir exposure; the geometric mean ratio (GMR) for grazoprevir plus ritonavir versus grazoprevir alone area under the concentration-time curve from 0 to 24 h (AUC0-24) was 1.91 (90% confidence interval [CI]; 1.31 to 2.79). Grazoprevir exposure was markedly increased with coadministration of atazanavir-ritonavir, lopinavir-ritonavir, and darunavir-ritonavir, with GMRs for grazoprevir AUC0-24 of 10.58 (90% CI, 7.78 to 14.39), 12.86 (90% CI, 10.25 to 16.13), and 7.50 (90% CI, 5.92 to 9.51), respectively. Elbasvir exposure was increased with coadministration of atazanavir-ritonavir, lopinavir-ritonavir, and darunavir-ritonavir, with GMRs for elbasvir AUC0-24 of 4.76 (90% CI, 4.07 to 5.56), 3.71 (90% CI, 3.05 to 4.53), and 1.66 (90% CI, 1.35 to 2.05), respectively. Grazoprevir and elbasvir had little effect on atazanavir, lopinavir, and darunavir pharmacokinetics. Coadministration of elbasvir-grazoprevir with atazanavir-ritonavir, lopinavir-ritonavir, or darunavir-ritonavir is contraindicated, owing to an increase in grazoprevir exposure. Therefore, HIV treatment regimens without HIV protease inhibitors should be considered for HCV/HIV-coinfected individuals who are being treated with elbasvir-grazoprevir.

The accuracy of baseline viral load for predicting the efficacy of elbasvir/grazoprevir in participants with hepatitis C virus genotype 1a infection: An integrated analysis.

European treatment guidelines for hepatitis C virus (HCV) infection recommend that people with genotype (GT) 1a infection and baseline viral load ≤800 000 IU/mL receive elbasvir/grazoprevir (EBR/GZR) for 12 weeks, and those with baseline viral load >800 000 IU/mL receive EBR/GZR plus ribavirin for 16 weeks. This analysis was conducted to clarify whether baseline viral load can serve as an accurate, sensitive or specific stratification factor for defining EBR/GZR regimens. In this post hoc, integrated analysis, participants with GT1a infection who received EBR 50 mg/GZR 100 mg for 12 weeks were stratified according to baseline viral load. Sustained virologic response at 12 weeks post-treatment was achieved by 95.2% (911/957) of participants and was higher among participants with baseline viral load ≤800 000 IU/mL vs >800 000 IU/mL (98.5% vs 93.9%). The 800 000 IU/mL threshold had a positive predictive value of 98.5%, a negative predictive value of 6.1%, a specificity of 91.3%, a sensitivity of 28.4% and an overall accuracy of 31.5%. A baseline viral load cutpoint of 800 000 IU/mL had high positive predictive value and specificity but poor negative predictive value, sensitivity and accuracy in predicting treatment outcomes in this population. Baseline NS5A resistance-associated substitutions (RASs) were detected in 25% (1/4) of virologic failures with baseline viral load ≤800 000 IU/mL and 59.5% (25/42) of those with baseline viral load >800 000 IU/mL. Overall, these data suggest that, compared with the use of a baseline viral load cutpoint, baseline testing for NS5A RASs enables more individuals to receive the 12-week EBR/GZR regimen without compromising the opportunity for SVR.

Effectiveness and safety of elbasvir/grazoprevir therapy in patients with chronic HCV infection: Results from the Spanish HEPA-C real-world cohort.

In randomized controlled trials of patients with chronic HCV infection, elbasvir/grazoprevir (EBR/GZR) demonstrated high cure rates and a good safety profile. This study assessed the effectiveness and safety of EBR/GZR, with and without ribavirin, in a real-world HCV patient cohort. HEPA-C is a collaborative, monitored national registry of HCV patients directed by the Spanish Association for the Study of the Liver and the Networked Biomedical Research Centre for Hepatic and Digestive Diseases. Patients entered into HEPA-C between December 2016 and May 2017, and treated with EBR/GZR with at least end-of-treatment response data, were included. Demographic, clinical and virologic data were analysed, and adverse events (AEs) recorded. A total of 804 patients were included in the study. The majority were male (57.9%), with a mean age of 60 (range, 19-92) years. Genotype (GT) distribution was GT 1, 86.8% (1a, 14.3%; 1b, 72.5%); GT 4, 13.2% and 176 patients (21.9%) were cirrhotic. Overall, among 588 patients with available data, 570 (96.9%) achieved sustained virologic response at 12 weeks post-treatment (SVR12). SVR12 rates by genotype were GT 1a, 97.7%; GT 1b, 98.6%; and GT 4, 98.1%. No significant differences in SVR12 according to fibrosis stage were observed. Eighty patients experienced an AE, resulting in treatment discontinuation in three. In this large cohort of patients with chronic HCV managed in a real-world setting in Spain, EBR/GZR achieved high rates of SVR12, comparable to those observed in randomized controlled trials, with a similarly good safety profile.

Real-world efficacy of elbasvir and grazoprevir for hepatitis C virus (genotype 1): A nationwide, multicenter study by the Japanese Red Cross Hospital Liver Study Group.

AIM: The present study aimed to determine the real-world efficacy and safety of the non-structural protein (NS)5A inhibitor elbasvir (EBR) combined with the NS3/4A protease inhibitor grazoprevir (GZR) in patients with hepatitis C virus (HCV) genotype 1 (GT1) infection. METHODS: This study retrospectively evaluated the rate of sustained virologic response at 12 weeks post-treatment (SVR12) and the safety of EBR/GZR treatment in 159 men and 194 women with a median age of 72 years, and it assessed factors associated with the SVR12 rate. The attending physicians were responsible for selecting candidate patients for EBR/GZR in this retrospective study. RESULTS: Treatment outcomes for EBR/GZR were good in direct-acting antiviral (DAA)-naïve patients, of whom 99.4% achieved SVR. Of 353 patients, 10 (2.9%) had treatment failure. Of these patients, eight previously underwent DAA therapy, and the remaining two had NS5A-L31/Y93 double mutation. The SVR rate was 50% (8/16 patients) in patients who previously underwent DAA therapy, and 18.2% (2/11 patients) in patients with NS5A-L31/Y93 double mutation. On multivariate logistic regression analysis, NS5A-Y31/Y93 double mutation (odds ratio 356.3; 95% confidence interval, 23.91-16 940; P < 0.0001) was identified as an independent predictor of treatment failure. No serious adverse events were observed with EBR/GZR therapy. CONCLUSIONS: The SVR rate of EBR/GZR would have been 100% in patients without either a history of DAA therapy or double mutation. This combination of drugs could be safely given and is, thus, considered a highly useful first-line treatment for DAA-naïve patients with HCV.

Efficacy and safety of elbasvir plus grazoprevir combination therapy in Japanese patients infected with hepatitis C virus genotype 1b.

AIM: Treatment with all-oral direct-acting antiviral agents (DAAs) elbasvir/grazoprevir (EBR/GZR) is associated with high sustained virologic response (SVR). The aim of this study was to evaluate the safety and treatment efficacy of EBR/GZR in hepatitis C virus (HCV)-infected patients. METHODS: This retrospective cohort study included 147 consecutive patients with chronic HCV genotype 1b infection who were treated with EBR (50 mg) plus GZR (100 mg) once daily for 12 weeks. The rates of SVR at 12 weeks after the end of treatment (SVR12) were evaluated based on patient baseline characteristics. Treatment efficacy was analyzed according to background chronic kidney disease (CKD), and retreatment efficacy in patients who failed to respond to previous DAAs. RESULTS: The SVR12 was 94% (138 of 147 patients), based on intention-to-treat analysis. Rates of SVR12 were 97% (131 of 135) and 58% (7 of 12) in cases naïve to DAA treatment and failure to respond to prior DAAs, respectively. The SVR12 rates in patients with CKD stage 4-5 was 100% (8 of 8). All patients (4 of 4 patients) with stage 4-5 and advanced fibrosis (Fibrosis-4 index ≥3.25) also achieved SVR12. Multivariate analysis that included the above variables identified pretreatment with other DAAs as an independent factor that was significantly and independently associated with non-SVR12 (odds ratio, 97.5; P < 0.001). Relapsers of first DAAs, excluding the combination of ledipasvir and sofosbuvir, achieved SVR12. Characteristic novel non-structural protein 5A substitutions were not detected after failure of retreatment with EBR/GZR. CONCLUSION: Treatment with EBR/GZR was highly efficacious with acceptable safety, even in patients with CKD stage 4-5. Retreatment of relapsers to prior DAAs, excluding ledipasvir and sofosbuvir, achieved SVR12.

Efficacy and safety of elbasvir/grazoprevir for Japanese patients with genotype 1b chronic hepatitis C complicated by chronic kidney disease, including those undergoing hemodialysis: A post hoc analysis of a multicenter study.

BACKGROUND AND AIM: This study aimed to evaluate the efficacy and safety of elbasvir/grazoprevir in genotype 1b chronic hepatitis C Japanese patients with chronic kidney disease (CKD), including those undergoing hemodialysis. METHODS: This post hoc analysis of a multicenter, retrospective study included patients who had received elbasvir/grazoprevir. CKD was defined by an estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m2 . The sustained virologic response (SVR) rate and frequency of treatment-emergent adverse events were assessed in patients with CKD. RESULTS: The study population comprised 155 men and 182 women. The median eGFR level at baseline was 69.6 mL/min/1.73 m2 (range, 3.0-128.5 mL/min/1.73 m2 ). Among the 337 patients, 109 (32.3%) had CKD: 72, 14, and 23 (including 20 hemodialysis) had CKD stages 3, 4, and 5, respectively. The SVR rates according to the baseline CKD stages were 98.1% (51/52) in stage 1, 98.3% (173/176) in stage 2, 93.9% (46/49) in stage 3a, 100% (23/23) in stage 3b, 100% (14/14) in stage 4, and 100% (23/23) in stage 5. All 20 patients undergoing hemodialysis achieved SVR. There was no significant decrease from baseline in the median eGFR level throughout the treatment period among the patients with CKD. The incidence of treatment-emergent adverse events was 6.4% (7/109) among the patients with CKD and 9.7% (22/228) among the patients without CKD (not significant, P = 0.323). CONCLUSIONS: The present study demonstrated that elbasvir and grazoprevir are highly effective and safe for genotype 1b chronic hepatitis C Japanese patients with CKD, including those undergoing hemodialysis.