Daclatasvir Research Articles

1016 All-Oral 12-Week Combination Treatment With Daclatasvir (DCV) and Sofosbuvir (SOF) in Treatment-Experienced Patients Infected With HCV Genotype (GT) 3: A Subanalysis of the Ally-3 Phase 3 Study

1016 All-Oral 12-Week Combination Treatment With Daclatasvir (DCV) and Sofosbuvir (SOF) in Treatment-Experienced Patients Infected With HCV Genotype (GT) 3: A Subanalysis of the Ally-3 Phase 3 Study

LP24 : Safety, efficacy and impact on liver function of simeprevir (SMV) in combination with daclatasvir (DCV) or sofosbuvir (SOF) in patients with severe hepatitis C recurrence after liver transplantation (LT): results from compassionate use in europe

LP24 : Safety, efficacy and impact on liver function of simeprevir (SMV) in combination with daclatasvir (DCV) or sofosbuvir (SOF) in patients with severe hepatitis C recurrence after liver transplantation (LT): results from compassionate use in europe

P0791 : Daclatasvir (DCV) combined with sofosbuvir (SOF) or simeprevir (SMV) in liver transplant (LT) recipients with severe recurrent HCV genotype 1 infection

P0791 : Daclatasvir (DCV) combined with sofosbuvir (SOF) or simeprevir (SMV) in liver transplant (LT) recipients with severe recurrent HCV genotype 1 infection

P0782 : All-oral 12-week combination treatment with daclatasvir (DCV) and sofosbuvir (SOF) in treatment-experienced patients infected with HCV genotype (GT) 3: A subanalysis of the ALLY-3 phase 3 study

P0782 : All-oral 12-week combination treatment with daclatasvir (DCV) and sofosbuvir (SOF) in treatment-experienced patients infected with HCV genotype (GT) 3: A subanalysis of the ALLY-3 phase 3 study

LP07 : Simeprevir (SMV) plus daclatasvir (DCV) and sofosbuvir (SOF) in treatment-naïve and -experienced patients with chronic hepatitis C virus genotype 1 or 4 infection and decompensated liver disease: Interim results from the phase II impact study

LP07 : Simeprevir (SMV) plus daclatasvir (DCV) and sofosbuvir (SOF) in treatment-naïve and -experienced patients with chronic hepatitis C virus genotype 1 or 4 infection and decompensated liver disease: Interim results from the phase II impact study

P0888 : Effect of baseline factors on response to the fixed-dose combination of daclatasvir (DCV), asunaprevir (ASV) and beclabuvir (BCV), with or without ribavirin (RBV), in patients with HCV genotype 1 infection and cirrhosis

P0888 : Effect of baseline factors on response to the fixed-dose combination of daclatasvir (DCV), asunaprevir (ASV) and beclabuvir (BCV), with or without ribavirin (RBV), in patients with HCV genotype 1 infection and cirrhosis

Daclatasvir inhibits hepatitis C virus NS5A motility and hyper-accumulation of phosphoinositides

Combinations of direct-acting antivirals (DAAs) against the hepatitis C virus (HCV) have the potential to revolutionize the HCV therapeutic regime. An integral component of DAA combination therapies is HCV NS5A inhibitors. It has previously been proposed that NS5A DAAs inhibit two functions of NS5A: RNA replication and virion assembly. In this study, we characterize the impact of a prototype NS5A DAA, daclatasvir (DCV), on HCV replication compartment formation. DCV impaired HCV replicase localization and NS5A motility. In order to characterize the mechanism behind altered HCV replicase localization, we examined the impact of DCV on the interaction of NS5A with its essential cellular cofactor, phosphatidylinositol-4-kinase III α (PI4KA). We observed that DCV does not inhibit PI4KA directly, nor does it impair early events of the NS5A–PI4KA interaction that can occur when NS5A is expressed alone. NS5A functions that are unaffected by DCV include PI4KA binding, as determined by co-immunoprecipitation, and a basal accumulation of the PI4KA product, PI4P. However, DCV impairs late steps in PI4KA activation that requires NS5A expressed in the context of the HCV polyprotein. These NS5A functions include hyper-stimulation of PI4P levels and appropriate replication compartment formation. The data are most consistent with a model wherein DCV inhibits conformational changes in the NS5A protein or protein complex formations that occur in the context of HCV polyprotein expression and stimulate PI4P hyper-accumulation and replication compartment formation.

Optimal therapy in genotype 4 chronic hepatitis C: finally cured?

Optimal therapy for patients with hepatitis C virus (HCV) genotype 4 (HCV-4) infection is changing rapidly, and the possibility of a total cure is near. The standard of care has been combination pegylated interferon (PEG-IFN)-ribavirin (RBV), with modest response rates and considerable adverse events. Since the introduction of sofosbuvir (SOF), simeprevir (SIM), and daclatasvir (DCV), the duration of treatment has been significantly shortened and response rates have increased. The recommended treatment for IFN-eligible patients is PEG-IFN/RBV plus SOF, SIM or DCV. In IFN ineligible patients, the optimal regimen is a 24-week course of SOF/RBV, or a 12-week course of SOF-SIM or SOF-DCV with or without RBV. The pipeline for patients with chronic HCV is highly active. IFN-free combinations with paritaprevir-ombitasvir, SOF-ledipasvir, or DCV-asunaprevir (ASV)-beclabuvir (BMS-791325) for 12 weeks or less with close to 100% cure rates will soon become the optimal therapy.

Structural Analysis of Asunaprevir Resistance in HCV NS3/4A Protease

Asunaprevir (ASV), an isoquinoline-based competitive inhibitor targeting the hepatitis C virus (HCV) NS3/4A protease, is very potent in vivo. However, the potency is significantly compromised by the drug resistance mutations R155K and D168A. In this study three crystal structures of ASV and an analogue were determined to analyze the structural basis of drug resistance susceptibility. These structures revealed that ASV makes extensive contacts with Arg155 outside the substrate envelope. Arg155 in turn is stabilized by Asp168, and thus when either residue is mutated, the enzyme’s interaction with ASV’s P2* isoquinoline is disrupted. Adding a P1–P3 macrocycle to ASV enhances the inhibitor’s resistance barrier, likely due to poising the inhibitor to its bound conformation. Macrocyclic inhibitors with P2* extension moieties avoiding interaction with the protease S2 residues including Arg155 must be chosen for future design of more robust protease inhibitors.

Another Effective All-Oral Regimen for HCV Genotype 1 Infection

Initial studies of daclatasvir, an NS5A replication complex inhibitor, plus asunaprevir, an NS3 protease inhibitor, for hepatitis C virus (HCV) infection demonstrated high rates of sustained virologic response (SVR) in genotype 1b infection but not in genotype 1a. Now, results of an industry-funded, phase III trial are available in treatment-naive, treatment-experienced, and interferon-ineligible and/or intolerant patients with HCV genotype 1b infection. …

Single-Dose Pharmacokinetics and Safety of Daclatasvir in Subjects with Renal Function Impairment

Daclatasvir (DCV) is a pangenotypic inhibitor of the HCV NS5A replication complex approved in Japan and Europe for combination treatment of HCV. AI444-063 was an open-label, two-stage, adaptive study assessing DCV pharmacokinetics and safety in HCV-uninfected subjects with renal impairment. Stage 1 included 12 subjects with end-stage renal disease (ESRD) on dialysis and 12 healthy controls (creatinine clearance [CLcr]≥90 ml/min, Cockcroft-Gault) matched by sex, age and weight. All participants received a single DCV 60-mg dose on day 1. DCV plasma levels were measured through day 4. Prespecified criteria for study expansion (ESRD versus control area under the curve extrapolated to infinite time [AUC∞] geometric mean ratio [GMR] upper 90% CI>1.5) were met; therefore, 12 subjects with moderate or severe renal impairment (estimated glomerular filtration rate, 30-59 and 15-29 ml/min/1.73m(2), respectively) were included in stage 2. All 36 participants (30 male, mean age 54 years) completed the study. DCV AUC∞ was higher in ESRD subjects versus controls (GMR 1.264, 90% CI 0.989, 1.616). Compared with normal CLcr (90 ml/min), GMR and 90% CI for unbound DCV AUC∞ at CLcr 60, 30 and 15 ml/min were 1.18 (1.07, 1.30), 1.39 (1.14, 1.70) and 1.51 (1.18, 1.94), respectively. DCV was generally well tolerated in subjects with normal renal function, ESRD, or moderate or severe renal impairment. Observed DCV exposure increases were within the normal range of variability and were not associated with an elevated risk of adverse events. DCV can be administered in subjects with renal impairment, including ESRD, without dose modification. ClinicalTrials.gov NCT01830205.

Different interaction profiles of direct-acting anti-hepatitis C virus agents with human organic anion transporting polypeptides.

Simeprevir (SMV), asunaprevir (ASV), daclatasvir (DCV), and sofosbuvir (SFV), which are newly developed direct-acting antiviral agents (DAAs) against hepatitis C virus (HCV) infection, are among the key components of anti-HCV regimens. Preclinical studies have identified inhibitory properties for some of these DAAs against organic anion transporting polypeptide 1B (OATP1B) functions. However, their details remain mostly uncharacterized. Because OATP1B1 and OATP1B3 play determinant roles in the pharmacokinetics of various drugs via their uptake into human hepatocytes, it is plausible that the inhibition of these OATP1Bs by a DAA would create a potential risk of drug-drug interaction, which has been an emerging concern in anti-HCV therapy. Accordingly, in the present study, we intended to clarify the inhibitory characteristics of newly developed DAAs toward OATP1B1 and -1B3 functions. The results of our coincubation inhibition assays have shown that all tested DAAs could inhibit OATP1B1 functions and that SMV, ASV, and DCV (to a lesser extent), but not SFV, exhibited long-lasting preincubation inhibitory effects on OATP1B1 functions. It was also found that the preincubation inhibitory effects of SMV and ASV could augment their coincubation inhibition potency. Furthermore, significant, but differential, inhibitory effects of the DAAs on the OATP1B3 function were identified. To summarize, our results clearly show that the newly developed DAAs are newly identified OATP1B1 and OATP1B3 inhibitors with distinctive interaction properties. It is believed that these inhibition profiles will provide essential information to all concerned parties with respect to the clinical significance of DAA-mediated inhibition of OATP1Bs in anti-HCV therapy.

The crystal structure of NS5A domain 1 from genotype 1a reveals new clues to the mechanism of action for dimeric HCV inhibitors

New direct acting antivirals (DAAs) such as daclatasvir (DCV; BMS-790052), which target NS5A function with picomolar potency, are showing promise in clinical trials. The exact nature of how these compounds have an inhibitory effect on HCV is unknown; however, major resistance mutations appear in the N-terminal region of NS5A that include the amphipathic helix and domain 1. The dimeric symmetry of these compounds suggests that they act on a dimer of NS5A, which is also consistent with the presence of dimers in crystals of NS5A domain 1 from genotype 1b. Genotype 1a HCV is less potently affected by these compounds and resistance mutations have a greater effect than in the 1b genotypes. We have obtained crystals of domain 1 of the important 1a NS5A homologue and intriguingly, our X-ray crystal structure reveals two new dimeric forms of this domain. Furthermore, the high solvent content (75%) makes it ideal for ligand-soaking. Daclatasvir (DCV) shows twofold symmetry suggesting NS5A dimers may be of physiological importance and serve as potential binding sites for DCV. These dimers also allow for new conformations of a NS5A expansive network which could explain its operation on the membranous web. Additionally, sulfates bound in the crystal structure may provide evidence for the previously proposed RNA binding groove, or explain regulation of NS5A domain 2 and 3 function and phosphorylation, by domain 1.

Ultradeep Sequencing Study of Chronic Hepatitis C Virus Genotype 1 Infection in Patients Treated with Daclatasvir, Peginterferon, and Ribavirin

Direct-acting antivirals (DAAs) are either part of the current standard of care or are in advanced clinical development for the treatment of patients chronically infected with hepatitis C virus (HCV) genotype 1, but concern exists with respect to the patients who fail these regimens with emergent drug-resistant variants. In the present study, ultradeep sequencing was performed to analyze resistance to daclatasvir (DCV), which is a highly selective nonstructural protein 5A (NS5A) inhibitor. Eight patients with HCV genotype 1b, who were either treatment naive or prior nonresponders to pegylated interferon plus ribavirin (Rebetol; Schering-Plough) (PEG-IFN/RBV) therapy, were treated with DCV combined with PEG-IFN alpha-2b (Pegintron; Schering-Plough, Kenilworth, NJ) and RBV. To identify the cause of viral breakthrough, the preexistence and emergence of DCV-resistant variants at NS5A amino acids were analyzed by ultradeep sequencing. Sustained virological response (SVR) was achieved in 6 of 8 patients (75%), with viral breakthrough occurring in the other 2 patients (25%). DCV-resistant variant Y93H preexisted as a minor population at higher frequencies (0.1% to 0.5%) in patients who achieved SVR. In patients with viral breakthrough, DCV-resistant variant mixtures emerged at NS5A-31 over time that persisted posttreatment with Y93H. Although enrichment of DCV-resistant variants was detected, the preexistence of a minor population of the variant did not appear to be associated with virologic response in patients treated with DCV/PEG-IFN/RBV. Ultradeep sequencing results shed light on the complexity of DCV-resistant quasispecies emerging over time, suggesting that multiple resistance pathways are possible within a patient who does not rapidly respond to a DCV-containing regimen. (This study has been registered at ClinicalTrials.gov under registration no. NCT01016912.).

Reply:

We enthusiastically agree with the conclusion of Galmozzi et al. that routine direct sequencing of HCV NS5A before starting daclatasvir (DCV) therapy is unnecessary. It is important to note that whereas E62D was detected as a baseline polymorphism in our study,1 we did not detect linkage of Q30R-E62D at baseline as claimed by Galmozzi et al. In our study, the naturally occurring polymorphisms in the NS5A sequences derived from multiple GT-1a- and -1b-infected patients have no effect on the potency of DCV (Tables 1B, 2B, and 3 of ref. 1). This included the E62D polymorphism in subject P-derived GT-1a NS5A. Therefore, we concluded the following: “This study indicates that the heterogeneity of HCV sequences in infected specimens with no detectable level of previously identified resistant substitutions has a minimal effect on the potency of BMS-790052,…”.1 We also concluded that polymorphisms in the NS5A sequence at baseline can significantly affect which resistance variants emerge. We and others have demonstrated that multiple GT1a NS5A substitutions (Q30E/R, L31M/V, and Y93C/H/N) are selected in vitro and in the clinic with NS5A inhibitors, including DCV.2 In our article, we showed that there are 23 amino acid differences in NS5A derived from the baseline sequence of subject P and the lab strain, H77c. When H77c NS5A was replaced with the corresponding region derived from subject P, the only resistance substitution that emerged with DCV selection was Q30R; other resistance variants previously identified were not detected (Q30E, L31M/V, and Y93C/H/N). Further genetic analysis demonstrated that Q30R-E62D linkage was responsible for the high level of DCV resistance. The conclusion that NS5A baseline polymorphisms affect which resistance variants emerge after selection with DCV was further confirmed in a recent study.3 In summary, our data are in agreement with the recommendation by Galmozzi et al. that routine direct sequencing of HCV NS5A before starting DCV therapy is unnecessary. Jin-Hua Sun M.SC.*, Min Gao PH.D.*, Susan Roberts PH.D.*, Robert Fridell PH.D.*, * Department of Virology, Bristol-Myers Squibb Research and Development, Wallingford, CT.

Combinations of Lambda Interferon with Direct-Acting Antiviral Agents Are Highly Efficient in Suppressing Hepatitis C Virus Replication

The clinical efficacy of a pegylated form of human lambda 1 interferon (IFN-λ1; also referred to herein as lambda) has been demonstrated in patients chronically infected with hepatitis C virus (HCV) representing genotypes 1 through 4. In these proof-of-concept studies, lambda showed an improved safety profile compared to the pegylated form of alpha interferon (referred to herein as alfa). In the study described in this report, an assessment of the in vitro antiviral activity of type III IFNs toward different HCV replicons revealed that the unpegylated recombinant form of IFN-λ1 (rIFN-λ1) exerted the most robust effect, while rIFN-λ3 exhibited greater activity than rIFN-λ2. More importantly, cross-resistance to rIFN-λ1 was not observed in replicon cell lines known to have reduced susceptibility to investigational direct-acting antiviral (DAA) agents targeting the essential HCV nonstructural protein NS3, NS5A, or NS5B. When combined with either rIFN-α, the NS3 protease inhibitor (NS3 PI) asunaprevir (ASV), the NS5A replication complex inhibitor (NS5A RCI) daclatasvir (DCV), or the NS5B polymerase site I inhibitor (NS5B I) BMS-791325, rIFN-λ1 displayed a mixture of additive and synergistic effects. In three-drug combination studies, inclusion of lambda with ASV and DCV also yielded additive to synergistic effects. In line with these observations, it was demonstrated that a regimen that used a combination of rIFN-λ1 with one or two DAAs was superior to an IFN-free regimen in clearing HCV RNA in genotype 1a cell lines representing wild-type and NS3 protease inhibitor-resistant sequences. Overall, these data support further clinical development of lambda as part of alternative combination treatments with DAAs for patients chronically infected with HCV.

Dual oral therapy with daclatasvir and asunaprevir for patients with HCV genotype 1b infection and limited treatment options

Improved therapeutic options for chronic hepatitis C virus (HCV) infection are needed for patients who are poor candidates for treatment with current regimens due to anticipated intolerability or low likelihood of response. In this open-label, phase 2a study of Japanese patients with chronic HCV genotype 1b infection, 21 null responders (<2 log₁₀ HCV RNA reduction after 12 weeks of peginterferon/ribavirin) and 22 patients intolerant to or medically ineligible for peginterferon/ribavirin therapy received dual oral treatment for 24 weeks with the NS5A replication complex inhibitor daclatasvir (DCV) and the NS3 protease inhibitor asunaprevir (ASV). The primary efficacy end point was sustained virologic response at 12 weeks post-treatment (SVR₁₂). Thirty-six of 43 enrolled patients completed 24 weeks of therapy. Serum HCV RNA levels declined rapidly, becoming undetectable in all patients on therapy by week 8. Overall, 76.7% of patients achieved SVR₁₂ and SVR₂₄, including 90.5% of null responders and 63.6% of ineligible/intolerant patients. There were no virologic failures among null responders. Three ineligible/intolerant patients experienced viral breakthrough and four relapsed post-treatment. Diarrhea, nasopharyngitis, headache, and ALT/AST increases, generally mild, were the most common adverse events; three discontinuations before week 24 were due to adverse events that included hyperbilirubinemia and transaminase elevations (two patients). Dual therapy with daclatasvir and asunaprevir, without peginterferon/ribavirin, was well tolerated and achieved high SVR rates in two groups of difficult-to-treat patients with hepatitis C virus genotype 1b infection.

Effect on Hepatitis C Virus Replication of Combinations of Direct-Acting Antivirals, Including NS5A Inhibitor Daclatasvir

Three hepatitis C virus (HCV) inhibitors, asunaprevir (ASV; BMS-650032), daclatasvir (DCV; BMS-790052), and BMS-791325, each targeting a different nonstructural protein of the virus (NS3, NS5A, and NS5B, respectively), have independently demonstrated encouraging preclinical profiles and are currently undergoing clinical evaluation. Since drug-resistant variants have rapidly developed in response to monotherapy with almost all direct-acting antiviral agents (DAAs) for HCV, the need for combination therapies to effectively eradicate the virus from infected patients is clear. These studies demonstrated the additive-synergistic effects on replicon inhibition and clearance of combining NS3 protease or NS5B RNA polymerase inhibitors with the first-in-class, NS5A replication complex inhibitor daclatasvir (DCV) and reveal new resistance pathways for combinations of two small-molecule inhibitors that differ from those that develop during monotherapy. The results suggest that under a specific selective pressure, a balance must be reached in the fitness costs of substitutions in one target gene when substitutions are also present in another target gene. Further synergies and additional novel resistance substitutions were observed during triple-combination treatment relative to dual-drug therapy, indicating that, in combination, HCV inhibitors can exert cross-target influences on resistance development. Enhanced synergies in replicon inhibition and a reduced frequency of resistance together lend strong support to the utility of combinations of DAAs for the treatment of HCV, and the identification of altered resistance profiles during combination treatment provides useful information for monitoring resistance in the clinic.