An evaluation of ledipasvir + sofosbuvir for the treatment of chronic hepatitis C infection

Introduction: Hepatitis C (HCV) is viral disease with a global impact. Over the last 10 years, the treatment of this disease has evolved. Treatment guidelines have evolved to adopt new medications for HCV. These drugs have shown efficacy over 90% throughout the class as well as a better safety profile than the previous recommended pharmacotherapy. Dual-therapy DAAs emerged with FDA approval of Ledipasvir/Sofosbuvir (LDV/SOF) in 2014.Areas Covered: LDV/SOF is a dual-therapy option for chronic HCV patients (>6 months of infection) in select genotypes. This article reviews the studies relevant to the pharmacokinetic/pharmacodynamic properties of these drugs as well as its trials leading to approval.Expert opinion: LDV/SOF is included in the AASLD/IDSA guidelines for the treatment of HCV genotypes 1a and 1b with or without cirrhosis and genotype 4 without cirrhosis with an evidence and recommendation rating of IA. Genotype 4 with cirrhosis and genotypes 5 and 6 carry a Class IIa level B recommendation. The combination is not FDA approved for genotypes 2 and 3. Single-pill regimens, like LDV/SOF, are important to maintain the quality of life of children and other special populations infected with HCV by shortening treatment regimens, avoiding complex pill regimens, and eliminating injection therapies.

Deferred treatment with a fixed-dose combination of sofosbuvir-velpatasvir for chronic hepatitis C virus genotype 1, 2, 4 and 6 infection

Sofosbuvir-velpatasvir is approved for the treatment of chronic hepatitis C virus (HCV) infection. In this single-arm, open-label, phase 3, deferred treatment study, we investigated the efficacy and safety of sofosbuvir-velpatasvir among patients randomized to the placebo group in the ASTRAL-1 study. Patients received sofosbuvir-velpatasvir (400/100 mg) once daily for 12 weeks. The primary efficacy endpoint was the proportion of patients with sustained virologic response 12 weeks after the end of therapy (SVR12). The primary safety endpoint was any adverse events (AEs) leading to the permanent discontinuation of study drug. Overall, 108/111 (97%, 95% confidence interval [CI], 92%-99%) achieved SVR12, and only one patient had virological failure. SVR12 was achieved by 61/63 (97%, 95%CI, 89%-100%) genotype 1 patients, 20/20 (100%; 95%CI, 83%-100%) with genotype 2, 19/19 (100%; 95%CI, 82%-100%) with genotype 4 and 8/9 (89%; 95% CI, 52%-100%) with genotype 6. All (19/19; 95%CI, 82-100) patients with cirrhosis and all (31/31, 95%CI, 89-100) with prior treatment experience achieved SVR12. The safety profile during treatment was similar to that observed in patients receiving placebo treatment. The most common AEs were headache, fatigue and nausea. One patient (1%) discontinued treatment due to an AE of gallbladder carcinoma, which was not considered related to treatment. Of five reported serious AEs, none were considered related to study drug. Sofosbuvir-velpatasvir for 12 weeks was effective and well tolerated among untreated and previously treated patients with HCV genotype 1, 2, 4 or 6 infection, including those with compensated cirrhosis (ClinicalTrials.gov NCT02346721).

Synthesis and biological evaluation of deuterated sofosbuvir analogs as HCV NS5B inhibitors with enhanced pharmacokinetic properties

A series of deuterated sofosbuvir analogs were designed and prepared with the aim of improving their pharmacokinetic properties. The devised synthetic routes allow for site-selective deuterium incorporation with high levels of isotopic purity. As expected, the deuterated analogs (37-44) are as efficacious as sofosbuvir when tested in vitro inhibition of viral replication (replicon) assays. Compared with sofosbuvir, deuterated analog 40 displays improved in vivo pharmacokinetics profiles in rats and dogs in terms of the metabolite and the prodrug. The Cmax and area under the curve (AUC) of 40 in dogs were increased by 3.4- and 2.7-fold, respectively. Due to the enhanced pharmacokinetic properties and the great synthetic advantage of an inexpensive deuterium source (D₂ O) for 40, it was chosen for further investigation.

Daclatasvir/asunaprevir/beclabuvir fixed-dose combination in Japanese patients with HCV genotype 1 infection

BACKGROUND

DCV-TRIO, a fixed-dose combination of daclatasvir (pangenotypic NS5A inhibitor), asunaprevir (NS3/4A protease inhibitor), and beclabuvir (non-nucleoside NS5B inhibitor), has achieved high rates of sustained virologic response at post-treatment Week 12 (SVR12) in phase 3 studies.

METHODS

In this phase 3 study, DCV-TRIO for 12 weeks and daclatasvir plus asunaprevir (DUAL) for 24 weeks were studied in Japanese patients infected with HCV genotype 1 (99 % genotype 1b).

RESULTS

SVR12 rates ≥95 % were achieved in both treatment-naive (N = 152) and interferon-experienced (N = 65) cohorts treated with DCV-TRIO for 12 weeks and were comparable across patient subgroups, including patients aged ≥65 years and those with cirrhosis. DUAL recipients (N = 75) had an SVR12 rate of 87 %. In the absence of baseline resistance-associated polymorphisms at positions NS5A-Y93H or -L31, SVR12 rates were 98 % with DCV-TRIO or DUAL. Among genotype 1b-infected patients with baseline Y93H or L31 polymorphisms, 35/38 (92 %) DCV-TRIO recipients, and 7/16 (44 %) DUAL recipients achieved SVR12. Adverse events, mostly liver related, led to treatment discontinuation in 10 % of DCV-TRIO recipients. In this group, SVR12 was achieved by 3/9 patients who discontinued before Week 4 and by 12/12 patients who completed ≥4 weeks of DCV-TRIO. Treatment-related serious adverse events occurred in 4 and 3 % of DCV-TRIO and DUAL recipients, respectively. Seven patients (9 %) discontinued DUAL due to adverse events. No deaths occurred.

CONCLUSION

SVR12 was achieved by 96 % of Japanese patients with HCV genotype 1 infection after 12 weeks of treatment with the DCV-TRIO regimen. DCV-TRIO and DUAL exhibited comparable safety profiles.

Prevalence of resistant associated variants (RAVs) in the naïve HCV patient candidate for direct acting antiviral (DAA) therapy

BACKGROUND

Viral hepatitis C is an important global health problem that affects about 2.2% of humans. Strategies on the control of this hepatotropic virus focused on chemotherapy and surveillance of emerging HCV drug resistant mutants, respectively. HCV genotype 1 response to therapy is one of major interests. The aim of this research was to study the prevalence of resistant associated variants (RAVs) in the naïve HCV patient candidate for direct acting antiviral (DAA) therapy.

METHODS

A total of 70 HCV confirmed patients which referred to hospitals affiliated to Iran University of Medial Sciences, Tehran, Iran from May 2014 to March 2015 were enrolled in this cross sectional study. After RNA extraction, RFLP-RT-Nested-PCR was performed for HCV genotyping, then some genotypes 1 and 3 strains were used for further amplification of NS5B gene S282T mutation site and purified products were sequenced. Bioinformatics software was used for analysis of sequences.

RESULTS

From a total of 70 HCV patients, 54 were male (mean age (y)±SD 35.1 ± 8.2) and 16 were female (mean age (y)±SD 43.4 ± 10.1); 26 isolates from 1a, 1b and 3a showed that there were no S282T resistant mutants. Moreover, 2 (4.8%) had a synonymous point mutation (C to T). Statistical analysis didn't found any significant correlation between age, sex and genotype variables.

CONCLUSION

Finally, it can be concluded that there were no resistant mutants in our HCV genotypes 1 and 3 infected patients and broader scale of studies are required in this area using larger specimens, genotype groups and stages of treatment.

Ledipasvir-sofosbuvir and sofosbuvir plus ribavirin in patients with chronic hepatitis C and bleeding disorders

INTRODUCTION

Chronic hepatitis C virus (HCV) infection is prevalent among patients with inherited bleeding disorders and is a leading cause of mortality in those with haemophilia.

AIM

We evaluated the efficacy and safety of ledipasvir-sofosbuvir and sofosbuvir plus ribavirin in patients with chronic HCV genotype 1-4 infection and an inherited bleeding disorder.

METHODS

Ledipasvir-sofosbuvir was administered for 12 weeks to patients with genotype 1 or 4 infection and for 12 or 24 weeks to treatment-experienced cirrhotic patients with genotype 1 infection. Patients with genotype 2 and 3 infection received sofosbuvir plus ribavirin for 12 and 24 weeks respectively.

RESULTS

The majority of the 120 treated patients had a severe bleeding disorder (55%); overall, 65% of patients had haemophilia A and 26% of patients had haemophilia B; 22% were HIV coinfected. Sustained virologic response at 12 weeks posttreatment was 99% (98/99) in patients with genotype 1 or 4 infection; 100% (5/5) in treatment-experienced cirrhotic patients with genotype 1 infection; 100% (10/10) in patients with genotype 2 infection; and 83% (5/6) in patients with genotype 3 infection. There were no treatment discontinuations due to adverse events (AEs). The most frequent non-bleeding AEs were fatigue, headache, diarrhoea, nausea and insomnia. Bleeding AEs occurred in 22 patients, of which all but one were considered unrelated to treatment.

CONCLUSION

Treatment with ledipasvir-sofosbuvir for patients with HCV genotype 1 or 4 infection or sofosbuvir plus ribavirin for patients with genotype 2 or 3 infection was highly effective and well tolerated among those with inherited bleeding disorders.

On-treatment HCV RNA as a predictor of sustained virological response in HCV genotype 3-infected patients treated with daclatasvir and sofosbuvir

BACKGROUND AND AIMS

Many currently available direct-acting antiviral (DAA) regimens are less effective against HCV genotype 3 than against other HCV genotypes. The all-oral, pangenotypic DAA combination of daclatasvir (NS5A inhibitor) + sofosbuvir (nucleotide NS5B inhibitor) was studied in genotype 3-infected treatment-naive and -experienced patients (ALLY-3) who achieved rates of sustained virological response at post-treatment Week 12 (SVR12) of 90 and 86% respectively. In this analysis, we assessed whether on-treatment responses to daclatasvir + sofosbuvir in genotype 3-infected patients could predict treatment outcome.

METHODS

In ALLY-3, treatment-naive and -experienced patients, with or without cirrhosis, were treated with daclatasvir + sofosbuvir for 12 weeks. HCV RNA kinetics and categorical virological responses on treatment were assessed. The proportions of responders and nonresponders by study week, and time to first undetectable HCV RNA, were analysed for utility in predicting treatment outcome.

RESULTS

Overall, HCV RNA levels declined rapidly during Week 1 of treatment in both treatment-naive and -experienced cohorts. Although patients with cirrhosis had a slower initial virological response as measured by the proportion of patients with HCV RNA below the lower limit of quantification at Week 1, responses converged thereafter. Positive and negative predictive values calculated for on-treatment responses were generally comparable with the overall SVR12 rate and were therefore limited indicators of outcome. SVR12 rates were not impacted by time to first undetectable HCV RNA.

CONCLUSIONS

On-treatment responses are not useful predictors of ultimate virological response to the daclatasvir + sofosbuvir regimen.

Sofosbuvir/velpatasvir: A promising combination

Hepatitis C virus (HCV) affects 3% of the world population. It represents the main cause of chronic liver disease and is responsible for extra-hepatic complications, such as type 2 diabetes and cardiovascular diseases. HCV includes 7 genotypes differing in the nucleotide sequence variability, the geographic distribution, the rates of viral clearance, the risk of progression to liver fibrosis and to hepatocellular carcinoma, and the response to therapy. Last years have seen remarkable advances in the field of HCV infection with the approval of direct antiviral agents (DAAs) targeting key viral proteins involved in the HCV replication. Several oral regimens combining DAAs from different families have been developed and these regimens showed increased and sustained virological response rates to above 90% reducing the treatment duration to 12 wk or less. In particular, sofosbuvir, a nucleotide analogue nonstructural (NS)5B polymerase inhibitor, and velpatasvir, a NS5A inhibitor, have been tested in two phase 3 trials, the ASTRAL-2 (against HCV genotype 2) and the ASTRAL-3 (against HCV genotype 3), demonstrating to be effective, safe, and well tolerated in patients who were 18 years of age or older and had at least a 6-mo history of HCV infection with a compensated liver disease.

Defining the possibilities: is short duration treatment of chronic hepatitis C genotype 1 with sofosbuvir-containing regimens likely to be as effective as current regimens?

This review summarizes published data on sofosbuvir-based regimens for patients infected with HCV GT1 with a focus on evaluating the optimal and possible durations of treatment.

METHODS

PubMed and conference abstract books published between 2011-2015 were searched.

RESULTS

HCV treatment has decreased from 24 week regimens to studies done as short as 4 weeks. History of prior treatment or cirrhosis have consistently shown lower SVR12 rates with shorter duration therapies. Low cure rates have been seen in patients within 4 week trials, however, select patients with low fibrosis scores, low HCV VL and HCV GT-1b have moderate cure rates.

CONCLUSION

Most patients will require 12-24 weeks of therapy. Further studies are needed to elucidate the predictors of treatment response to short duration therapies and optimal combination of DAAs.

A randomized, double blind, dose escalation, first time in human study to assess the safety, tolerability, pharmacokinetics, and antiviral activity of single doses of GSK2485852 in chronically infected hepatitis C subjects

This first-time-in-human, randomized, double-blind, placebo-controlled, dose-escalation study assessed the safety, tolerability, pharmacokinetics, and antiviral activity of GSK2485852, a hepatitis C virus (HCV) NS5B inhibitor, in 27 chronically infected HCV genotype-1 subjects. Subjects received GSK2485852 70, 420, and 70 mg with a moderate fat/caloric meal. Safety, pharmacokinetics, antiviral activity, HCV genotype/phenotype, and interleukin 28B genotype were evaluated. A statistically significant reduction in HCV ribonucleic acid (RNA) was observed after a single dose of 420 mg GSK2485852 (-1.33 log10  IU/mL) compared with placebo (-0.09 log10  IU/mL) at 24 hours post-dose. Subjects receiving 70 mg GSK2485852 were exposed to concentrations above the protein-adjusted 90% effective concentration for a short time; none experienced a significant decline in HCV RNA (-0.47 log10  copies/mL). GSK2485852 was readily absorbed; however, the observed geometric mean maximum plasma concentration (Cmax ) and area under the curve (AUC) values were significantly lower than expected due to a higher-than-predicted-oral clearance. Co-administration with food reduced the AUC and Cmax of GSK2485852 by 40% and 70%, respectively. Two metabolites were detected in human blood with one having approximately 50% higher concentrations than those of the parent. GSK2485852 was well-tolerated and exhibited antiviral activity after a single 420 mg dose in HCV subjects.