Hiroki Ishikawa

Daclatasvir Plus Asunaprevir for Chronic HCV Genotype 1b Infection

All‐oral combinations of direct‐acting antivirals may improve efficacy and safety outcomes for patients with hepatitis C virus (HCV) infection, particularly those who are poor candidates for current interferon/ribavirin‐based regimens. In this open‐label, phase 3 study, 135 interferon‐ineligible/intolerant and 87 nonresponder patients with chronic HCV genotype 1b infection were enrolled at 24 centers in Japan. Patients received daclatasvir 60 mg once daily plus asunaprevir 100 mg twice daily for 24 weeks. The primary endpoint was sustained virologic response 24 weeks after treatment (SVR24). This study is registered with ClinicalTrials.gov (NCT01497834). SVR24 was achieved by 87.4% of interferon‐ineligible/intolerant patients and 80.5% of nonresponder (null and partial) patients; rates were similar in cirrhosis (90.9%) and noncirrhosis (84.0%) patients, and in patients with IL28B CC (84.5%) or non‐CC (84.8%) genotypes. Fourteen patients in each group (12.6%) discontinued dual therapy, mainly due to adverse events or lack of efficacy. Nine nonresponder patients received additional treatment with peginterferon/ribavirin per protocol‐defined criteria. The rate of serious adverse events was low (5.9%) and varied among patients. The most common adverse events were nasopharyngitis, increased alanine aminotransferase (ALT) and aspartate aminotransferase (AST), headache, diarrhea, and pyrexia. Conclusion: Interferon‐free, ribavirin‐free all‐oral therapy with daclatasvir and asunaprevir for 24 weeks is well tolerated and can achieve a high rate of SVR in patients with HCV genotype 1b who were ineligible, intolerant, or had not responded to prior interferon‐based therapy. (Hepatology 2014;59:2083–2091)

Dual therapy with the nonstructural protein 5A inhibitor, daclatasvir, and the nonstructural protein 3 protease inhibitor, asunaprevir, in hepatitis C virus genotype 1b-infected null responders.

Patients with chronic hepatitis C virus (HCV) infection and previous null response to pegylated interferon (Peg‐IFN) and ribavirin (RBV) have limited therapeutic options. HCV genotype 1 is the most common worldwide and the most difficult to treat; genotype 1b is the most common subtype of genotype 1 outside North America. The enhanced antiviral activity achieved by combining two direct‐acting antiviral (DAA) agents may improve clinical outcomes. This open‐label, phase IIa study included 10 patients with chronic HCV genotype 1b infection and previous null response (<2 log10 reduction in HCV RNA after 12 weeks) to Peg‐IFN and RBV. Patients received dual DAA treatment for 24 weeks with the nonstructural protein 5A replication complex inhibitor, daclatasvir (60 mg once‐daily), and the nonstructural protein 3 protease inhibitor, asunaprevir (initially 600 mg twice‐daily, then subsequently reduced to 200 mg twice‐daily). The primary efficacy endpoint was the proportion of patients with sustained virologic response (SVR) at 12 weeks post‐treatment (SVR12). Nine patients completed 24 weeks of treatment; 1 patient discontinued treatment after 2 weeks. In the 9 patients who completed the full course of treatment, HCV RNA was undetectable at week 8 and remained undetectable through the end of treatment; all 9 patients achieved SVR12 and SVR24. HCV RNA also remained undetectable post‐treatment in the patient who discontinued after 2 weeks. There was no viral breakthrough. Diarrhea and headache, generally mild, were the most common adverse events; transaminase elevations were reported in 3 patients, but did not result in discontinuation. Conclusions: Dual therapy with daclatasvir and asunaprevir, without Peg‐IFN and RBV, can achieve high SVR rates in difficult‐to‐treat patients with HCV genotype 1b infection and previous null response to Peg‐IFN and RBV. (HEPATOLOGY 2011)

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

BACKGROUND & AIMSnImproved 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.nnnMETHODSnIn 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).nnnRESULTSnThirty-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).nnnCONCLUSIONSnDual 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.

Characterization of virologic escape in hepatitis C virus genotype 1b patients treated with the direct-acting antivirals daclatasvir and asunaprevir.

BACKGROUND & AIMSnDaclatasvir and asunaprevir are NS5A and NS3 protease-targeted antivirals currently under development for treatment of chronic hepatitis C virus infection. Clinical data on baseline and on-treatment correlates of drug resistance and response to these agents are currently limited.nnnMETHODSnHepatitis C virus genotype 1b Japanese patients (prior null responders to PegIFN-α/RBV [n=21] or PegIFN-α/RBV ineligible or intolerant [n=22]) were administered daclatasvir/asunaprevir for 24 weeks during a phase 2a open-label study. Genotypic and phenotypic analyses of NS3 and NS5A substitutions were performed at baseline, after virologic failure, and post-treatment through follow-up week 36.nnnRESULTSnThere were three viral breakthroughs and four relapsers. Baseline NS3 polymorphisms (T54S, Q80L, V170M) at amino acid positions previously associated with low-level resistance (<9-fold) to select NS3 protease inhibitors were detected in four null responders and three ineligibles, but were not associated with virologic failure. Baseline NS5A polymorphisms (L28M, L31M, Y93H) associated with daclatasvir resistance (<25-fold) were detected in five null responders and six ineligibles. All three viral breakthroughs and 2/4 relapsers carried a baseline NS5A-Y93H polymorphism. NS3 and NS5A resistance-associated variants were detected together (NS3-D168A/V, NS5A-L31M/V-Y93H) after virologic failure. Generally, daclatasvir-resistant substitutions persisted through 48weeks post-treatment, whereas asunaprevir-resistant substitutions were no longer detectable. Overall, 5/10 patients with baseline NS5A-Y93H experienced virologic failure, while 5/10 achieved a sustained virologic response.nnnCONCLUSIONSnThe potential association of a pre-existing NS5A-Y93H polymorphism with virologic failure on daclatasvir/asunaprevir combination treatment will be examined in larger studies. The persistence of treatment-emergent daclatasvir- and asunaprevir-resistant substitutions will require assessment in longer-term follow-up studies.

Long-term use of entecavir in nucleoside-naïve Japanese patients with chronic hepatitis B infection.

BACKGROUND & AIMSnTo evaluate the long-term efficacy of entecavir in nucleoside-naïve chronic hepatitis B patients.nnnMETHODSnOne hundred and sixty-seven patients treated with entecavir 0.01mg, 0.1mg or 0.5mg for 24-52weeks in Phase II studies entered rollover study ETV-060 and received entecavir 0.5mg daily. Responses were evaluated among patients with available samples.nnnRESULTSnAfter 96weeks in ETV-060 (120-148weeks total entecavir treatment time), 88% (127/144) of patients had HBV-DNA <400 copies/ml; 90.1% (128/142) had alanine aminotransferase (ALT) 1x the upper limit of normal (ULN) among those with abnormal baseline ALT; and 26% (32/121) achieved HBe seroconversion among those HBeAg(+) at baseline. A subset of 66 patients received entecavir 0.5mg (approved dose) from Phase II baseline: at week 96 in ETV-060, 83% (48/58) had HBV-DNA <400 copies/ml, 88% (52/59) had ALT 1x ULN, and 20% (10/49) achieved HBe seroconversion. Twenty-one out of 66 patients had paired baseline and on-treatment biopsies: 100% (21/21) and 57% (12/21) demonstrated histologic improvement, and improvement in fibrosis, respectively, over 3years. The 3-year cumulative probability of resistance was 3.3% for all patients and 1.7% for the 0.5mg subset.nnnCONCLUSIONSnLong-term entecavir for nucleoside-naïve patients resulted in high rates of virological, biochemical, and histological response, with minimal resistance.

High Sustained Virologic Response to Daclatasvir Plus Asunaprevir in Elderly and Cirrhotic Patients with Hepatitis C Virus Genotype 1b Without Baseline NS5A Polymorphisms

IntroductionOral daclatasvir (DCV; pangenotypic NS5A inhibitor) plus asunaprevir (ASV; NS3 protease inhibitor) is approved in Japan and Korea for treatment of chronic hepatitis C virus (HCV) genotype 1. Response to DCVxa0+xa0ASV is affected by DCV resistance-associated polymorphisms (RAPs) in HCV NS5A. The prevalence and influence of these RAPs on 12-week sustained virologic response (SVR12) to DCVxa0+xa0ASV was evaluated in Asian and non-Asian patients.MethodsData were pooled from 5 national and international studies of patients with HCV genotype 1b (GT-1b) receiving DCVxa0+xa0ASV at their recommended doses. Baseline NS5A RAPs and their effect on SVR12 were assessed overall, in older (≥65xa0years) patients, patients with cirrhosis, and in patients stratified by baseline HCV RNA or prior treatment experience with interferon-based therapy.ResultsBaseline NS5A sequences were available from 988 patients (374 Japanese; 125 Korean/Taiwanese; 489 from non-Asian countries), 979 of whom were assessed for SVR12. Pretreatment NS5A-L31F/I/M/V and/or NS5A-Y93H polymorphisms were present in 18% of Japanese and 12–13% of non-Japanese patients; these RAPs reduced SVR12 by 54.9% overall (93.9% [787/838] SVR12 when absent, 39.0% [55/141] SVR12 when present), with comparable reductions observed in Asians and non-Asians and across all categories of treatment experience, age, and cirrhosis. RAP-associated SVR12 rates declined with increasing baseline HCV RNA (SVR12 with RAPs: 64.7% [11/17] at 5-6 log10 IU/mL, 29.8% [14/47] at 7–8 log10). Without baseline RAPs, very high SVR12 rates (92–100%) were observed in older patients and patients with cirrhosis irrespective of national origin, with similarly high rates observed among treatment-naïve and interferon-experienced patients and those with high baseline HCV RNA.ConclusionsFollowing DCVxa0+xa0ASV treatment, the SVR12 rates in GT-1b patients without baseline NS5A-L31F/I/M/V and/or NS5A-Y93H polymorphisms were very high (approximately 90–100%), irrespective of age, cirrhosis, prior interferon treatment, or baseline HCV RNA.FundingBristol-Myers Squibb.

A randomized trial of daclatasvir with peginterferon alfa-2b and ribavirin for HCV genotype 1 infection.

BACKGROUNDnDaclatasvir-containing regimens have the potential to address limitations of current regimens combining peginterferon alfa and ribavirin with first-generation protease inhibitors for treatment of chronic HCV genotype 1 infection.nnnMETHODSnIn this randomized, double-blind study, 27 Japanese treatment-naive patients received once-daily daclatasvir 10 mg or 60 mg or placebo, each combined with peginterferon alfa-2b/ribavirin; 18 prior null (n=9) or partial (n=9) responders received the same daclatasvir-containing regimens without a placebo arm. Daclatasvir recipients with protocol-defined response (HCV RNA<15 IU/ml at week 4, undetectable at week 12) were treated for 24 weeks; those without protocol-defined response and placebo recipients continued treatment to week 48.nnnRESULTSnSustained virological response 24 weeks post-treatment (SVR24) was achieved by 66.7%, 90.0% and 62.5% of treatment-naive patients in the daclatasvir 10 mg, 60 mg and placebo groups, respectively. Prior non-responders had more frequent virological failure; 22.2% and 33.3% of daclatasvir 10 mg and 60 mg recipients, respectively, achieved SVR24. Adverse events were similar across groups and were typical of peginterferon alfa-2b/ribavirin. Pyrexia, headache, alopecia, decreased appetite and malaise were the most common adverse events; two daclatasvir recipients discontinued due to adverse events.nnnCONCLUSIONSnDaclatasvir 60 mg combined with peginterferon alfa-2b and ribavirin achieved a high rate of SVR24 in treatment-naive patients with HCV genotype 1 infection, with tolerability similar to that of peginterferon alfa-2b/ribavirin alone. However, regimens with greater antiviral potency are needed for prior non-responders.

Randomized comparison of daclatasvir + asunaprevir versus telaprevir + peginterferon/ribavirin in Japanese hepatitis C virus patients

Daclatasvir combined with asunaprevir is the first all‐oral, ribavirin‐free treatment of hepatitis C virus genotype 1b infection in Japan. This study compared the efficacy and safety of daclatasvir plus asunaprevir versus telaprevir plus peginterferon/ribavirin in Japanese treatment‐naive patients infected with hepatitis C virus genotype 1b.

Virological escape in HCV genotype-1-infected patients receiving daclatasvir plus ribavirin and peginterferon alfa-2a or alfa-2b.

BACKGROUNDnDaclatasvir (DCV; BMS-790052) is a picomolar inhibitor of HCV non-structural protein 5A (NS5A) and has demonstrated efficacy in patients chronically infected with HCV.nnnMETHODSnIn the double-blind, randomized studies AI444021 and AI444022, 71 Japanese patients chronically infected with HCV genotype 1 (predominantly genotype 1b) received DCV (10 mg or 60 mg) plus peginterferon alfa-2b or alfa-2a and ribavirin. Virological failure occurred in 14% (5/36) of treatment-naive patients and 54% (19/35) of prior alfa/ribavirin non-responders. Resistance testing was performed on baseline samples and samples with HCV RNA≥1,000 IU/ml at week 1 through post-treatment week 24.nnnRESULTSnBaseline NS5A resistance-associated polymorphisms had less impact on virological response rates than IL28B genotype. All patients with virological failure had NS5A DCV-resistant variants at the time of failure. The predominant NS5A variants were L31V/M/I plus Y93H; this combination was detected in 100% (5/5) of treatment-naive patients and 74% (14/19) of non-responders with failure. Emergent resistance variants in prior non-responders (four viral breakthroughs, one relapse) were more varied with novel combinations such as L31F-ΔP32 and L28M-R30Q-A92K detected. Significant loss in DCV antiviral activity was generally only seen with ≥ two resistance-associated NS5A substitutions. All DCV-resistant variants were still detected at end of study.nnnCONCLUSIONSnVirological failure in HCV genotype 1b treatment-naive Japanese patients receiving DCV plus alfa-2a/ribavirin or alfa-2b/ribavirin was associated with enrichment of NS5A resistance variants L31V/M-Y93H. In prior non-responders, emergent variants associated with failure also included NS5A-A92K or NS5A-ΔP32. As with L31-Y93 variants, these variants persisted.

Daclatasvir combined with peginterferon alfa-2a and ribavirin in Japanese patients infected with hepatitis C genotype 1.

BACKGROUNDnNew direct-acting antiviral agents are currently being developed to treat chronic HCV. The efficacy and safety of daclatasvir combined with peginterferon alfa-2a (alfa-2a) and ribavirin were assessed in a randomized, double-blind Phase IIa study of Japanese patients with chronic HCV genotype-1 infection.nnnMETHODSnJapanese patients who were treatment-naive (n=25) or prior null (n=12) or partial (n=5) responders received once-daily daclatasvir 10 mg or 60 mg or placebo in combination with alfa-2a and ribavirin. Daclatasvir recipients with a protocol-defined response (HCV RNA<15 IU/ml at week 4 and undetectable at week 12) were treated for 24 weeks; placebo recipients and patients without a protocol-defined response were treated for 48 weeks.nnnRESULTSnSustained virological response at 24 weeks post-treatment (SVR24) was achieved by 89% and 100% of treatment-naive patients receiving daclatasvir 10 mg and 60 mg, respectively, versus 75% in placebo recipients. Virological failure was more frequent in prior non-responder patients, with 50% and 78% achieving SVR24 in daclatasvir 10 mg and 60 mg groups, respectively. Adverse events occurred with similar frequency among treatment groups and were consistent with the adverse event profile of alfa-2a/ribavirin alone. The most commonly reported adverse events included pyrexia, alopecia, anaemia, lymphopenia, neutropenia, pruritus and diarrhoea. Three patients discontinued treatment due to anaemia.nnnCONCLUSIONSnDaclatasvir combined with alfa-2a/ribavirin in treatment-naive patients showed greater efficacy than alfa-2a/ribavirin alone and was generally well tolerated. The 60-mg dose of daclatasvir achieved the highest rates of SVR24 in both treatment-naive and non-responder populations and will be evaluated in a Phase III clinical trial.