NS5A Inhibitor Ledipasvir Research Articles

Safety and efficacy of sofosbuvir–velpatasvir–voxilaprevir for re-treatment of chronic hepatitis C virus infection in patients with previous direct-acting antiviral treatment failure in Rwanda (SHARED-3): a single-arm trial

Hepatitis C virus (HCV) genotype 4 non-a/d subtypes, which frequently have NS5A resistance-associated substitutions, are highly prevalent in sub-Saharan Africa. These subtypes, particularly genotype 4r, have been associated with higher rates of failure of treatment regimens containing the NS5A inhibitors ledipasvir or daclatasvir, which are the most accessible direct-acting antivirals in low-income countries. Clinical evidence regarding the efficacy of re-treatment options for these subtypes is limited. We aimed to evaluate the safety and efficacy of sofosbuvir-velpatasvir-voxilaprevir for the treatment of adults in Rwanda with chronic HCV infection, predominantly of genotype 4, and a history of direct-acting antiviral treatment failure. In this single-arm prospective trial, we enrolled adults (aged ≥18 years) with a HCV RNA titre of at least 1000 IU/mL, and a documented history of direct-acting antiviral failure. Patients were assessed for eligibility at a single study site after referral from hospitals with HCV treatment programmes throughout Rwanda, and participants for whom sofosbuvir-ledipasvir treatment had failed in the previous SHARED trial were also included. Participants with decompensated liver disease or hepatitis B virus co-infection were excluded. Participants were treated once daily with an oral fixed-dose combination tablet containing sofosbuvir (400 mg), velpatasvir (100 mg), and voxilaprevir (100 mg) for 12 weeks. The primary endpoint was the proportion of participants with a sustained virological response 12 weeks after completion of treatment (SVR12) in the intention-to-treat population. Viral sequencing of NS3, NS5A, and NS5B genes was done at baseline in all participants and at end of follow-up (week 24) in participants with treatment failure. The study is registered with ClinicalTrials.gov (NCT03888729) and is completed. Between Sept 23, 2019, and Jan 10, 2020, 49 individuals were screened and 40 participants were enrolled. 20 (50%) were female, 20 (50%) were male, median age was 63 years (IQR 56-68), and median HCV viral load was 6·2 log10 IU/mL (5·8-6·5) at baseline. The genotype subtypes identified were 4r (18 [45%] participants), 4k (six [15%]), 4b (five [13%]), 4q (four [10%]), 4l (two [5%]), 4a (one [3%]), 4m (one [3%]), and 3h (one [3%]). One (3%) genotype 4 isolate could not be subtyped, and one (3%) isolate was of unknown genotype. All successfully sequenced isolates (33 [83%]) had at least two NS5A resistance-associated substitutions and 25 (63%) had three or more. 39 (98% [95% CI 87-100]) participants had SVR12. Seven (18%) participants had a total of ten grade 3, 4, or 5 adverse events, including three (8%) cases of hypertension, and one (3%) case each of cataract, diabetes, gastrointestinal bleeding, joint pain, low back pain, vaginal cancer, and sudden death. Four of these events were categorised as serious adverse events resulting in hospitalisation. The one sudden death occurred at home from an unknown cause 4 weeks after the completion of treatment. No serious adverse event was determined to be related to the study drug or resulted in treatment discontinuation. A 12 week course of sofosbuvir-velpatasvir-voxilaprevir is safe and efficacious for the re-treatment of individuals infected with HCV genotype 4 non-a/d subtypes with frequent baseline NS5A resistance-associated substitutions, following failure of previous direct-acting antiviral treatment. Improved affordability and access to sofosbuvir-velpatasvir-voxilaprevir in regions with these subtypes is crucial. Gilead Sciences.

Outcomes of Real-World Integrated HCV Microelimination for People Who Inject Drugs: An expansion of the Punjab Model.

BackgroundThe prevalence of chronic hepatitis C (CHC) in People Who Inject Drugs (PWID) is 8-10% as compared to 3·6% in the general population in Punjab, India. We assessed the real-world efficacy and safety of free-of-charge generic direct-acting antivirals (DAAs), sofosbuvir with an NS5A inhibitor (ledipasvir, daclatasvir or velpatasvir)±ribavirin in the microelimination of CHC in PWID in a public health setting.MethodsAn integrated care team at 25 sites provided algorithm based DAAs treatment to PWID supervised by telemedicine clinics between 18th June 2016 and 31st July 2019. The primary endpoint was sustained virological response at 12 weeks (SVR-12); the secondary endpoints were treatment completion, adherence, safety, and adverse events. ClinicalTrials.gov number: NCT01110447.FindingsWe enrolled 3477 PWID (87·2% men; mean age 33·6±12·5 years; 83·8% rural; 6·8% compensated cirrhosis). While 2280 (65·5%) patients completed treatment, 1978 patients completed 12 weeks of follow up for SVR-12. SVR-12 was achieved in 91·1% of patients per protocol, 49.5% as per intention to treat (ITT) and 90·1% in a modified ITT analysis. Of 546 (15·7%) patients with treatment interruptions, 99 (19·7%) could be traced to test for SVR-12 with a cure rate of 77·8%. There were no major adverse events or consequent treatment discontinuation.InterpretationIntegrated care of PWID with CHC with DAAs is safe and effective. Measures for reducing treatment interruptions will further improve outcomes.FundingThe Government of the state of Punjab, India under the Mukh Mantri Punjab Hepatitis C Relief Fund (MMPHCRF) project, funds the project.

Efficacy of NS5A inhibitors against unusual and potentially difficult-to-treat HCV subtypes commonly found in sub-Saharan Africa and South East Asia

The efficacy of NS5A inhibitors against several less common subtypes of hepatitis C virus (HCV) is poorly characterised. Some subtypes including 3b, 3g, 6u and 6v commonly harbour amino acid residues in NS5A that may confer resistance to direct-acting antivirals (DAAs) in other common subtypes. Data from patients also suggest that 1l and 4r with amino acid substitutions at positions 28-31 and 93 in NS5A are relatively resistant to DAA therapy. In this study, we tested the efficacy of daclatasvir, elbasvir, ledipasvir, pibrentasvir and velpatasvir against these subtypes using the SGR-JFH1 replicon backbone. NS5A inhibitors showed different levels of efficacy with only pibrentasvir effective against all tested subtypes. Daclatasvir and ledipasvir were ineffective against 6u and 6v (half maximal effective concentration [EC50] values of 239-321 nM) while 3b and 3g were only susceptible to pibrentasvir. Analysis of effects of individual mutations indicated that Q30R in 1l increased the EC50 of ledipasvir by 18-fold, conferring intermediate resistance, while those of L31M and Y93H in 4r induced increases in EC50 values of 2,100- and 3,575-fold (high-level resistance). The high ledipasvir EC50 values of 1l with the Q30R substitution, 4r L31M and 4r Y93H may explain the treatment failure in patients who were infected with these viruses and treated with ledipasvir+ sofosbuvir. This study also shows the ineffectiveness of the first generation NS5A inhibitors against 6u and 6v, and confirms the inherent resistance of 3b and 3g to most NS5A inhibitors. Clinical studies to confirm invivo sensitivity to NS5A inhibitors are urgently needed so that rational, effective treatment strategies may be developed for unusual subtypes. Little is known about the efficacy of NS5A inhibitors against some "unusual" hepatitis C virus (HCV) subtypes including 1l, 3b, 3g, 4r, 6u and 6v. In this study, we manufactured HCV replicons which express the NS5A protein from the unusual HCV subtypes 1l, 3b, 3g, 4r, 6u, 6v. We then tested the effect of the NS5A inhibitors daclatasvir, elbasvir, ledipasvir, pibrentasvir and velpatasvir on blocking replication, using these replicons. We show that these replicons are resistant at some level to all NS5A inhibitors other than pibrentasvir.

COMBINED NS5A & NS5B NUCLEOTIDE INHIBITOR THERAPY FOR PATIENTS WITH CHRONIC HEPATITIS C WITH STAGE 5 CHRONIC KIDNEY DISEASE ON HEMODIALYSIS.

Hepatitis C virus (HCV) infection is the most common hepatotropic viral infection affecting the patients on maintenance hemodialysis. Treatment of chronic HCV infection in stage 4 and 5 CKD includes a combination of elbasvir/grazoprevir and glecaprevir/pibrentasvir, which are not available in many countries. Hence, we have conducted this study to look for the safety and efficacy of sofosbuvir combination therapy in this difficult to treat population. We conducted a single-center, prospective, open-label study in which Stage 5 CKD patients on maintenance hemodialysis with HCV infection. Total of 18 patients was included. sofosbuvir with daclatasvir or ledipasvir was used according to genotype for 12 weeks. HCV RNA, genotype, transient elastography (TE) was considered for every patient. HCV RNA was quantified at 4th week, 12th week and 12 weeks post-treatment to look for sustained virologic response (SVR 12). Infection due to genotype 1 was seen in 12 (66.7%) patients followed by genotype 3 in 4 (22.3%) with each patient of genotype 2 and 5. The median value of HCV RNA was 2,35,000 IU/mL. On TE, all had liver stiffness of <9.4 KPa. All patients had HCV RNA of <15 IU/mL at 4th and 12th week of treatment and 12 weeks post-treatment. No significant change in hemoglobin, eGFR and liver stiffness was observed. Full dose sofosbuvir i.e. 400 mg, in combination with NS5A inhibitors daclatasvir or ledipasvir is found to be safe and effective in patients with end stage renal disease, who are on maintenance hemodialysis.

Frequent Antiviral Treatment Failures in Patients Infected With Hepatitis C Virus Genotype 4, Subtype 4r.

Hepatitis C virus (HCV) genotype 4 is highly heterogeneous. HCV subtype 4r has been suggested to be less responsive to direct-acting antiviral (DAA) drug treatment than other genotype 4 subtypes. Among 537 DAA-treated patients who experienced a virological failure (VF) in France between 2015 and 2018, 121 (22.5%) were infected with genotype 4 and 27 of them (22.3%) with subtype 4r; subtype 4r was thus over-represented as compared to its prevalence in the French general population. Population sequencing of the nonstructural protein (NS) 3, NS5A, and NS5B genes was performed in all subtype 4r patients at treatment failure and in 6 at baseline, whereas full-length HCV genome sequencing was performed in two baseline and three treatment failure samples by means of an original shotgun metagenomics method based on deep sequencing. At treatment failure, all subtype 4r patients harbored two to three dominant NS5A resistance-associated substitutions (RASs), including at least L28A/C/I/M/V and L30R. Among 13 patients exposed to sofosbuvir and an NS5A inhibitor (daclatasvir, ledipasvir, or velpatasvir), 5 (38.5%) also harbored NS5B S282C/T RASs at treatment failure. An additional patient harbored S282C/T RASs at treatment failure by deep sequencing. Prevalence of S282C/T RASs at treatment failure was significantly higher in patients infected with genotype 4r than with other genotypes, including other subtypes of genotype 4. Conclusion: The lower rates of sustained virological response in patients infected with subtype 4r are related to the frequent preexistence at treatment baseline and subsequent selection by DAA treatment of both NS5A and NS5B S282 RASs. Our study suggests that these patients should be identified and receive a triple DAA combination regimen as first-line treatment.

Pre-treatment antiviral resistance in Australians with chronic hepatitis C: prevalence of NS3 and NS5A resistance data in the state of New South Wales.

Direct-acting antivirals (DAAs) have revolutionized HCV treatment, but the impact of antiviral resistance at a population level is still not clear. The majority of patients who fail DAA therapy develop resistance-associated substitutions (RASs), which can impact re-treatment. There is potential for resistance prevalence to rise in the community with treatment scale up, due to transmission of resistant virus. Monitoring for increasing antiviral resistance requires a reliable baseline, yet there are few published data on the prevalence of HCV resistance in Australia. The aim of this study was to determine the prevalence of RASs among untreated Australians with HCV genotype-1a infection, to inform ongoing surveillance. A cross-sectional study was performed at a single large university hospital pathology laboratory in Australia. Archived blood samples referred for HCV genotype testing were analysed. All patients were naive to DAAs. The prevalence of RASs in the HCV NS3 and NS5A regions was determined using Sanger based population sequencing. Of 379 samples tested, 34% contained DAA-resistant virus: 24% had resistance to NS3 protease inhibitors, 12% had NS5A inhibitor resistance and 4% of patients had resistance to both drug classes. Clinically relevant RASs conferring resistance against NS5A inhibitors ledipasvir, daclatasvir and elbasvir were detected in 5.8% of samples. This is the largest study of HCV antiviral drug resistance in Australia, which differs from resistance prevalence in the USA. The results provide valuable data on the baseline prevalence of HCV resistance, which can be used in the future to monitor for increasing antiviral resistance.

Drug-Drug Interaction Profile of the Fixed-Dose Combination Tablet Regimen Ledipasvir/Sofosbuvir.

Ledipasvir/sofosbuvir (Harvoni®), a fixed-dose combination tablet of an NS5A inhibitor ledipasvir and an NS5B polymerase inhibitor sofosbuvir, is approved for the treatment of chronic hepatitis C virus infection. Ledipasvir/sofosbuvir exhibits a favorable drug-drug interaction profile and can be administered with various medications that may be used by hepatitis C virus-infected patients, including patients with comorbidities, such as co-infection with human immunodeficiency virus or immunosuppression following liver transplantation. Ledipasvir/sofosbuvir is not expected to act as a victim or perpetrator of cytochrome P450- or UDP-glucuronosyltransferase 1A1-mediated drug-drug interactions. With the exception of strong inducers of P-glycoprotein, such as rifampin, ledipasvir/sofosbuvir is not expected to act as a victim of clinically relevant drug-drug interactions. As a perpetrator of pharmacokinetic drug-drug interactions via P-glycoprotein/BCRP, ledipasvir/sofosbuvir should not be used with rosuvastatin and elvitegravir/cobicistat/emtricitabine/tenofovir disoproxil fumarate, whereas its co-administration with amiodarone is not recommended because of a pharmacodynamic interaction. This review summarizes a number of drug interaction studies conducted in support of the clinical development of ledipasvir/sofosbuvir.

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Efficacy of Ledipasvir and Sofosbuvir Treatment of HCV Infection in Patients Coinfected With HBV

There have been reports of reactivation of hepatitis B virus (HBV) infection during treatment of hepatitis C virus (HCV) infection with direct-acting antiviral agents. We performed a prospective study of risks and outcomes of HCV infection treatment with ledipasvir and sofosbuvir in patients with HBV infection. We performed a phase 3b, multicenter, open-label study in Taiwan of 111 patients with HCV infection (61% HCV genotype 1, 39% HCV genotype 2 infection; 62% women, 16% with compensated cirrhosis) along with HBV infection. All but 1 were positive for the hepatitis B surface antigen (HBsAg); 1 patient who was HBsAg-positive at screening was found to be HBsAg-negative at baseline. Overall, 33% of participants had received prior treatment for HCV and 5% had previously been treated for HBV; no patient was on HBV therapy at the start of the study. All patients received a fixed-dose combination of 90 mg of the HCV NS5A inhibitor ledipasvir with 400 mg of the NS5B nucleotide analogue inhibitor sofosbuvir, once daily for 12 weeks. The primary endpoint was sustained virologic response 12 weeks after the end of therapy. All 111 patients (100%) achieved a sustained virologic response. Of the 37 patients with baseline HBV DNA below 20 IU/mL, 31 (84%) had at least 1 episode of quantifiable HBV DNA through posttreatment week 12. Of the 74 patients with baseline HBV DNA levels of 20 IU/mL or more, 39 (53%) had increases of HBV DNA greater than 1 log10 IU/mL through posttreatment week 12. Overall, 5 patients had increased levels of HBV DNA concomitant with a level of alanine aminotransferase >2 times the upper limit of normal through posttreatment week 12. Of these, 3 patients started HBV treatment. In addition, 1 patient with HBV reactivation since week 8 and concomitant alanine aminotransferase elevation >2 times upper limit of normal at posttreatment week 48 started treatment at posttreatment week 53. This patient had clinical signs and symptoms associated with HBV reactivation. The most common adverse events were headache, upper respiratory infection, and fatigue. In a prospective study, the combination of ledipasvir and sofosbuvir for 12 weeks produced a sustained virologic response in 100% of patients with HCV infection who were coinfected with HBV. Most patients had an increase in level of HBV DNA not associated with signs or symptoms. ClinicalTrials.gov no: NCT02613871.

INF-free sofosbuvir-based treatment of post-transplant hepatitis C relapse – a Swedish real life experience

Background: Relapse of hepatitis C virus (HCV) infection after liver transplantation has been universal, and the fibrosis progression faster than in non-transplanted patients. Interferon (IFN)-free treatment with direct antiviral agents (DAA) has improved the treatment outcome dramatically. We here report on the outcome of IFN-free treatment for HCV relapse after liver transplantation in a real life setting in Sweden.Material: In total, 93 patients with a mean age of 60 years (range 32–80) with HCV relapse after liver transplantation were given sofosbuvir-based treatment in combination with a protease inhibitor (simeprevir) or a NS5A inhibitor (daclatasvir or ledipasvir) with or without addition of ribavirin (RBV), or sofosbuvir and RBV only. Treatment was generally given during 24 weeks for advanced fibrosis or cirrhosis cases and 12 weeks for mild fibrosis with fibrosis stage 2 or less. The distribution of genotype 1, 2, 3, 4 in our patients was 58, 7.5, 26.5 and 7.5%, respectively.Results: All recipients reached end-of-treatment response (ETR) with HCV RNA <15 IU/mL. Sustained viral response 12 weeks after treatment cessation (SVR12) was achieved in 91/93 (97.8%) recipients. The SVR12 rates for genotype 1, 2, 3 and 4 were the SVR12 rate were 96, 100, 100 and 100%, respectively (p = .04).Conclusion: It is concluded that IFN-free treatment with DAAs for HCV relapse after liver transplantation is highly effective also in a real life setting and offers cure for most recipients.

Preclinical Characterization of the Novel HCV NS3 Protease Inhibitor GS-9256

GS-9256 is an inhibitor of HCV NS3 protease with a macrocyclic structure and novel phosphinic acid pharmacophore. Key preclinical properties of GS-9256 including in vitro antiviral activity, cross-resistance and pharmacokinetic properties were investigated in non-human species. In genotype (GT) 1b Huh-luc cells with a replicon encoding luciferase, GS-9256 had a mean 50% effective concentration (EC50) value of 20.0 nM, with minimal cytotoxicity. Antiviral activity was similar in a number of additional GT1b and GT1a replicon cell lines. Similar potency was observed in chimeric replicons encoding the NS3 protease of GT1 clinical isolates. GS-9256 was less active in GT2a replicon cells (14.2-fold increase in EC50). Additive to synergistic in vitro antiviral activity was observed when GS-9256 was combined with other agents including interferon-α, ribavirin, NS5B polymerase inhibitors GS-6620 and tegobuvir, as well as the NS5A inhibitor ledipasvir. GS-9256 retained wild-type activity against all tested NS5B and NS5A inhibitor resistance mutations. GS-9256 was metabolically stable in microsomes and hepatocytes of tested species, including rodents, dogs and humans. GS-9256 had high bioavailability in mice (near 100%) and moderate bioavailability in rats (14%), dogs (21%) and monkeys (14%). Elimination half-lives were approximately 2 h in mice, 0.6 h in rats, 5 h in dogs and 4 h in monkey. A study in bile duct-cannulated rats indicated that the major route of elimination is through biliary excretion of unmetabolized GS-9256. GS-9256 showed a favourable preclinical profile supportive of clinical development for the treatment of chronic HCV infection in GT1 patients.

Clinical Pharmacokinetics and Pharmacodynamics of Ledipasvir/Sofosbuvir, a Fixed-Dose Combination Tablet for the Treatment of Hepatitis C

Ledipasvir/sofosbuvir (Harvoni®), a fixed-dose combination tablet of an NS5A inhibitor ledipasvir and an NS5B polymerase inhibitor sofosbuvir, is approved in the US, European Union, Canada, and other regions for the treatment of chronic hepatitis C virus infection in adults. Following absorption, ledipasvir reaches maximum plasma concentrations (T max) 4-4.5h post-dose and is eliminated with a terminal half-life (t 1/2) of 47h. Sofosbuvir undergoes intracellular activation to an active triphosphate GS-461203 (not detected in plasma) and ultimately to GS-331007, a predominant circulating metabolite, which is the primary analyte of interest in clinical pharmacology studies. Sofosbuvir is rapidly absorbed and eliminated from plasma (T max: 0.8-1h; t 1/2: 0.5h). The peak plasma concentrations for GS-331007 are achieved between 3.5 and 4h post-dose; the elimination t 1/2 for GS-331007 is 27h. Ledipasvir/sofosbuvir exhibits a favorable clinical pharmacology profile; it can be administered once daily without regard to food and does not require dose modification in hepatitis C virus-infected patients with any degree of hepatic impairment or mild to moderate renal impairment. The pharmacokinetic profiles of ledipasvir, sofosbuvir, and GS-331007 (predominant circulating metabolite of sofosbuvir) are not significantly affected by demographic variables; pharmacokinetic/pharmacodynamic analyses reveal no exposure-response relationships for efficacy or safety. The review summarizes the clinical pharmacokinetics, pharmacodynamics, and pharmacokinetic/pharmacodynamic analyses for ledipasvir/sofosbuvir.

Ledipasvir-sofosbuvir in patients with hepatitis C virus genotype 5 infection: an open-label, multicentre, single-arm, phase 2 study

Data about the response of hepatitis C virus (HCV) genotype 5 to approved and experimental treatment regimens are scarce. We assessed the efficacy and safety of combination therapy with the NS5A inhibitor ledipasvir and the NS5B polymerase inhibitor sofosbuvir in patients with HCV genotype 5. We did this open-label, multicentre, single-arm, phase 2 trial at five hospitals in France. Eligible patients were at least 18 years old and had chronic infection with HCV genotype 5, with plasma HCV RNA of at least 10,000 IU/mL. We used BLAST analyses of NS5B partial sequences to establish the genotype and subtype at screening. Patients were given a fixed-dose combination tablet of 90 mg ledipasvir and 400 mg sofosbuvir orally once per day for 12 weeks. The primary endpoint was the proportion of patients with a sustained viral response, defined as HCV RNA concentration less than 15 IU/mL at 12 weeks after the end of treatment (SVR12). We analysed efficacy and safety in all patients who received at least one dose of ledipasvir-sofosbuvir. This trial is registered with EudraCT, number 2013-003978-27, and with ClinicalTrials.gov, number NCT02081079. From March 7 to June 10, 2014, we recruited 41 patients, including 21 who were treatment naive and 20 who were treatment experienced. All patients were of white ethnic origins. All 41 patients who started treatment completed the full 12 weeks of treatment and had undetectable HCV RNA at their final treatment visit. In the overall study population, 39 (95%, 95% CI 83-99) of 41 patients achieved SVR12. SVR12 was achieved by 20 (95%, 76-100) of the 21 patients who were treatment naive and 19 (95%, 75-100) of the 20 patients who were treatment experienced. Eight (89%) of nine patients with cirrhosis achieved SVR12, whereas 31 (97%) of the 32 patients without cirrhosis achieved SVR12. The two patients who did not reach SVR12 both had IL28B TT genotype and had viral relapse within 4 weeks of the end of treatment. The most common adverse events were asthenia (16 [39%] patients), headache (11 [27%] patients), and fatigue (four [10%] patients). One patient had a serious adverse event, worsening depression, which we judged to be unrelated to study treatment. The oral regimen of ledipasvir-sofosbuvir is an effective and well-tolerated treatment for patients with HCV genotype 5 infection who are treatment naive or treatment experienced. Gilead Sciences.

Treatment of HCV in Patients who Failed First-Generation PI Therapy: a Review of Current Literature.

The addition of the first direct-acting antiviral agents, the NS3 protease inhibitors boceprevir or telaprevir, to peg interferon and ribavirin was a major advance in the treatment of genotype 1 hepatitis C individuals with sustained virological response (SVR) rates of 63-75%. Those who did not achieve SVR had high rates of resistance-associated variants against NS3 protease domain. Retreatment options for those who have failed first-generation protease inhibitors generally are guided by retreatment with direct-acting antiviral agents from other classes. Phase 2 and phase 3 data have demonstrated that retreatment with 12-24weeks of a NS5B inhibitor (sofosbuvir) in combination with a NS5a inhibitor (daclatasvir or ledipasvir) with or without ribavirin can achieve SVR at high rates comparable to treatment-naive individuals.

Once daily ledipasvir/sofosbuvir fixed-dose combination with ribavirin in patients with inherited bleeding disorders and hepatitis C genotype 1 infection.

People with inherited bleeding disorders have been disproportionally affected by HCV. We assessed the fixed-dose combination of the NS5A inhibitor ledipasvir (LDV) with the NS5B polymerase inhibitor sofosbuvir (SOF) with ribavirin (RBV) in patients with genotype 1 HCV and inherited bleeding disorders. To be eligible, patients had to be over 18years of age and have an inherited bleeding disorder. HCV treatment-naïve and -experienced patients could enrol. All patients received LDV 90mg per SOF 400mg once daily and weight-based RBV in a divided dose for 12weeks. The primary efficacy endpoint was sustained virologic response (SVR), defined as HCV RNA below the limit of detection (15IUmL-1 ) 12weeks after the end of treatment (SVR12). Of the 14 patients enrolled, 8 (57%) had haemophilia A, 3 (21%) had haemophilia B and 2 (14%) had von Willebrand disease, and 1 (7%) had factor XIII deficiency. All 14 patients (100%, 95% CI: 77-100%) achieved SVR12. Treatment was well tolerated: all patients completed therapy, with mostly mild adverse events. No specific safety concerns associated with the patient's underlying bleeding disorders were noted. These results appear to suggest that people with HCV and inherited bleeding disorders can be safely and effectively treated with 12weeks of LDV/SOF plus RBV.

Ledipasvir and Sofosbuvir Plus Ribavirin for Treatment of HCV Infection in Patients With Advanced Liver Disease

There are no effective and safe treatments for chronic hepatitis C virus (HCV) infection of patients who have advanced liver disease. In this phase 2, open-label study, we assessed treatment with the NS5A inhibitor ledipasvir, the nucleotide polymerase inhibitor sofosbuvir, and ribavirin in patients infected with HCV genotypes 1 or 4. Cohort A enrolled patients with cirrhosis and moderate or severe hepatic impairment who had not undergone liver transplantation. Cohort B enrolled patients who had undergone liver transplantation: those without cirrhosis; those with cirrhosis and mild, moderate, or severe hepatic impairment; and those with fibrosing cholestatic hepatitis. Patients were assigned randomly (1:1) to receive 12 or 24 weeks of a fixed-dose combination tablet containing ledipasvir and sofosbuvir, once daily, plus ribavirin. The primary end point was sustained virologic response at 12 weeks after the end of treatment (SVR12). We enrolled 337 patients, 332 (99%) with HCV genotype 1 infection and 5 (1%) with HCV genotype 4 infection. In cohort A (nontransplant), SVR12 was achieved by 86%-89% of patients. In cohort B (transplant recipients), SVR12 was achieved by 96%-98% of patients without cirrhosis or with compensated cirrhosis, by 85%-88% of patients with moderate hepatic impairment, by 60%-75% of patients with severe hepatic impairment, and by all 6 patients with fibrosing cholestatic hepatitis. Response rates in the 12-and 24-week groups were similar. Thirteen patients (4%) discontinued the ledipasvir and sofosbuvir combination prematurely because of adverse events; 10 patients died, mainly from complications related to hepatic decompensation. The combination of ledipasvir, sofosbuvir, andribavirin for 12 weeks produced high rates of SVR12 in patients with advanced liver disease, including those with decompensated cirrhosis before and after liver transplantation. ClinTrials.gov: NCT01938430.

The Changing Face of Hepatitis C: Recent Advances on HCV Inhibitors Targeting NS5A

Current treatment for HCV infections consists of approved direct acting antivirals (DAAs), viz. the protease inhibitors (boceprevir, telaprevir, and simeprevir), NS5B polymerase inhibitors (sofosbuvir) and NS5A inhibitor (ledipasvir) in combination with pegylated interferon α and ribavirin). These treatments have made a great improvement in the treatment of chronic HCV infections in recent years, but their adverse side effects, emergence of resistant mutants, high cost, and increased pill burden have limited their clinical use. Recently, with the increasing knowledge in understanding the HCV life cycle, more targets have been recognized. NS5A protein plays a critical role in assembly of infectious HCV particles and offering potential for HCV therapies. Therefore, discovery and development of novel DAAs targeting NS5A with novel mechanisms of action, is of great necessity to improve the quality of existing HCV treatments. In the present review, we discuss recent advances with NS5A inhibitors with potent anti-HCV activity, and the potential for the development of HCV NS5A inhibitors to combat HCV infections.

New era in the treatment of chronic hepatitis C - novel direct acting antivirals

Chronic hepatitis C, without treatment, can cause liver cirrhosis, liver failure and liver cancer. The availability of new oral direct acting antivirals, such as the protease inhibitors simeprevir, asunaprevir and paritaprevir, the NS5A inhibitors daclatasvir, ledipasvir, and ombitasvir, the polymerase inhibitors Sofosbuvir and dasabuvir have resulted an enormous progress in the treatment of chronic hepatitis C, leading to >90% sustained viral response rates. Even the hard-to-treat or previously treatment ineligible patients can be cured with the combination of these drugs. Furthermore the treatment duration is much shorter, and the side effects are minimal. Today, treatment of all hepatitis C virus infected patients is recommended, and the best choices are the interferon-free options. Eradication of hepatitis C virus has become realistic, however, appropriate screening programs are mandatory to achieve this goal.

Ledipasvir and sofosbuvir fixed-dose combination with and without ribavirin for 12 weeks in treatment-naive and previously treated Japanese patients with genotype 1 hepatitis C: an open-label, randomised, phase 3 trial

Compared with other countries, patients with chronic hepatitis C infection in Japan tend to be older, have more advanced liver disease, and are more likely to have been previously treated for hepatitis C. We aimed to assess the efficacy and safety of an all-oral, fixed-dose combination of the hepatitis C virus NS5A inhibitor ledipasvir and the NS5B nucleotide polymerase inhibitor sofosbuvir with and without ribavirin for 12 weeks in treatment-naive and previously treated Japanese patients with chronic genotype 1 hepatitis C virus infection. In this randomised, open-label study, we enrolled patients from 19 clinical Japanese centres. Patients were randomly assigned (1:1) to receive either ledipasvir (90 mg) and sofosbuvir (400 mg) or ledipasvir, sofosbuvir, and ribavirin (dosed according to the Japanese Copegus product label-ie, patients ≤60 kg received 600 mg daily, patients >60 kg to ≤80 kg received 800 mg daily, and patients >80 kg received 1000 mg daily) orally once daily for 12 weeks. After completion or early discontinuation of treatment, patients were followed up off-treatment for 24 weeks. Eligible patients were at least 20 years of age with chronic genotype 1 hepatitis C virus infection with serum hepatitis C virus RNA concentrations of at least 5 log10 IU/mL, creatinine clearance of at least 1·0 mL/s, and a platelet count of at least 50 × 10(9) per L. An interactive web response system was used to manage patient randomisation and treatment assignment. Randomisation was stratified by the presence or absence of cirrhosis for treatment-naive patients and stratified by presence or absence of cirrhosis and by previous treatment category (relapser or breakthrough, non-responder, or interferon-intolerant) for previously treated patients. Within each strata, patients were sequentially assigned to either treatment with ledipasvir-sofosbuvir or ledipasvir-sofosbuvir plus ribavirin in a 1:1 ratio with block size of 4. The primary endpoint was sustained virological response 12 weeks after completion of treatment (SVR12) assessed in all patients who were randomly assigned and received at least one dose of study drug; safety outcomes were assessed in all patients who received at least one dose of study drug. This trial is registered with ClinicalTrials.gov, number NCT01975675. Between Oct 15, 2013 and Dec 13, 2013, 341 patients were randomly assigned to treatment groups and received at least one dose of study treatment. SVR12 was achieved in all 171 (100%) patients (83 of 83 treatment naive and 88 of 88 treatment experienced) receiving ledipasvir-sofosbuvir (95% CI 98-100) and 167 (98%) of 170 patients (80 of 83 treatment naive and 87 of 87 treatment experienced) receiving ledipasvir-sofosbuvir plus ribavirin (95% CI 95-100). Of the 76 patients with baseline NS5A resistant variants, 75 (99%) achieved SVR12. Two (1·2%) of 170 patients in the ledipasvir-sofosbuvir plus ribavirin group discontinued treatment because of adverse events. The most common adverse events were nasopharyngitis (50 [29·2%] of 171), headache (12 [7·0%] of 171), and malaise (nine [5·3%] of 171) in patients receiving ledipasvir-sofosbuvir; and nasopharyngitis (40 [23·5%] of 170), anaemia (23 [13·5%] of 170), and headache in those receiving ledipasvir-sofosbuvir and ribavirin (15 [8·8%] of 170). Although existing regimens for the treatment of hepatitis C virus are effective for many patients, medical needs remain unmet, particularly in Japan where the population with hepatitis C virus genotype 1 is generally older and treatment-experienced, with advanced liver disease. The efficacy, tolerability, and absence of drug-drug interactions of ledipasvir-sofosbuvir suggest that it could be an important option for treatment of genotype 1 hepatitis C virus in Japanese patients. Gilead Sciences.

Fast hepatitis C virus RNA elimination and NS5A redistribution by NS5A inhibitors studied by a multiplex assay approach.

While earlier therapeutic strategies for the treatment of hepatitis C virus (HCV) infection relied exclusively on interferon (IFN) and ribavirin (RBV), four direct-acting antiviral agents (DAAs) have now been approved, aiming for an interferon-free strategy with a short treatment duration and fewer side effects. To facilitate studies on the mechanism of action (MOA) and efficacy of DAAs, we established a multiplex assay approach, which employs flow cytometry, a Gaussia luciferase reporter system, Western blot analysis, reverse transcription-quantitative PCR (RT-qPCR), a limited dilution assay (50% tissue culture infectious dose [TCID50]), and an image profiling assay that follows the NS5A redistribution in response to drug treatment. We used this approach to compare the relative potency of various DAAs and the kinetics of their antiviral effects as a potential preclinical measure of their potential clinical utility. We evaluated the NS5A inhibitors ledipasvir (LDV) and daclatasvir (DCV), the NS3/4A inhibitor danoprevir (DNV), and the NS5B inhibitor sofosbuvir (SOF). In terms of kinetics, our data demonstrate that the NS5A inhibitor LDV, followed closely by DCV, has the fastest effect on suppression of viral proteins and RNA and on redistribution of NS5A. In terms of MOA, LDV has a more pronounced effect than DCV on the viral replication, assembly, and infectivity of released virus. Our approach can be used to facilitate the study of the biological processes involved in HCV replication and help identify optimal drug combinations.