Preliminary study of two antiviral agents for hepatitis C genotype 1.

BACKGROUND: Patients with chronic hepatitis C virus (HCV) infection who have not had a response to therapy with peginterferon and ribavirin may benefit from the addition of multiple direct-acting antiviral agents to their treatment regimen. METHODS: This open-label, phase 2a study included an exploratory cohort of 21 patients with chronic HCV genotype 1 infection who had not had a response to previous therapy (i.e., had not had ≥2 log(10) decline in HCV RNA after ≥12 weeks of treatment with peginterferon and ribavirin). We randomly assigned patients to receive the NS5A replication complex inhibitor daclatasvir (60 mg once daily) and the NS3 protease inhibitor asunaprevir (600 mg twice daily) alone (group A, 11 patients) or in combination with peginterferon alfa-2a and ribavirin (group B, 10 patients) for 24 weeks. The primary end point was the percentage of patients with a sustained virologic response 12 weeks after the end of the treatment period. RESULTS: A total of 4 patients in group A (36%; 2 of 9 with HCV genotype 1a and 2 of 2 with genotype 1b) had a sustained virologic response at 12 weeks after treatment and also at 24 weeks after treatment.. Six patients (all with HCV genotype 1a) had viral breakthrough while receiving therapy, and resistance mutations to both antiviral agents were found in all cases; 1 patient had a viral response at the end of treatment but had a relapse after the treatment period. All 10 patients in group B had a sustained virologic response at 12 weeks after treatment, and 9 had a sustained virologic response at 24 weeks after treatment. Diarrhea was the most common adverse event in both groups. Six patients had transient elevations of alanine aminotransferase levels to more than 3 times the upper limit of the normal range. CONCLUSIONS: This preliminary study involving patients with HCV genotype 1 infection who had not had a response to prior therapy showed that a sustained virologic response can be achieved with two direct-acting antiviral agents only. In addition, a high rate of sustained virologic response was achieved when the two direct-acting antiviral agents were combined with peginterferon alfa-2a and ribavirin. (Funded by Bristol-Myers Squibb; ClinicalTrials.gov number, NCT01012895.).

Randomized trial of asunaprevir plus peginterferon alfa and ribavirin for previously untreated genotype 1 or 4 chronic hepatitis C.

BACKGROUND & AIMS: Asunaprevir is a selective HCV NS3 protease inhibitor, active against genotypes 1, 4, 5, and 6 in vitro. We evaluated asunaprevir plus peginterferon alfa-2a/ribavirin (PegIFNα/RBV) for genotype 1 and 4 chronic HCV. METHODS: In this phase 2b, double-blind, placebo-controlled study, treatment-naive adults with genotype 1 (n=213) or 4 (n=25) were randomly assigned (3:1) to asunaprevir 200mg or placebo twice daily plus PegIFNα/RBV. Asunaprevir recipients, achieving protocol-defined response (HCV-RNA below quantification limit at week 4 and undetectable at week 10), were rerandomized at week 12 to continue asunaprevir-based triple therapy or receive placebo plus PegIFNα/RBV for weeks 13-24. Patients without protocol-defined response (PDR) and placebo recipients continued PegIFNα/RBV through week 48. Co-primary end points were undetectable HCV-RNA at week 4 and 12 (eRVR) and 24 weeks posttreatment (SVR24). RESULTS: Most patients were male (64.3%), white (83.6%), and had non-CC IL28B genotypes (71.3%). Among genotype 1 patients, eRVR rates (asunaprevir vs. placebo) were 67% (80% CI 62, 72) vs. 6% (80% CI 2, 10); corresponding SVR24 rates were 64% (80% CI 59, 68) vs. 44% (80% CI 36, 53). SVR24 among genotype 4 patients was 89% (asunaprevir) vs. 43% (placebo). Rates of rash and haematologic adverse events were similar between treatment groups. Five asunaprevir-treated patients had grade 4 alanine aminotransferase elevations that resolved following discontinuation (n=4) or with continued dosing (n=1). CONCLUSIONS: Addition of asunaprevir to PegIFNα/RBV in treatment-naive genotype 1- or 4-infected patients improves response rates and is well tolerated, with aminotransferase elevations that were manageable with appropriate monitoring. ClinicalTrials.gov ID: NCT01030432.

Randomized trial of daclatasvir and asunaprevir with or without PegIFN/RBV for hepatitis C virus genotype 1 null responders.

BACKGROUND & AIMS: Patients with chronic hepatitis C virus (HCV) infection and prior null response (<2 log HCV RNA decline after ⩾ 12 weeks of PegIFN/RBV) have limited options. We evaluated daclatasvir plus once- or twice-daily asunaprevir in non-cirrhotic genotype 1 null responders. METHODS: In this randomized, phase 2a, open-label, 24-week treatment study, 101 patients received daclatasvir (60 mg) once-daily. In addition, 38 genotype 1b patients received asunaprevir (200mg) twice- (DUAL A1) or once-daily (DUAL A2); 36 genotype 1a and 5 genotype 1b patients received asunaprevir twice- (QUAD B1) or once-daily (QUAD B2) plus PegIFN/RBV; and 18 genotype 1a and 4 genotype 1b patients received asunaprevir twice-daily plus ribavirin (TRIPLE B3). The primary endpoint was undetectable HCV RNA 12 weeks post-treatment (sustained virologic response, SVR12). RESULTS: Across all groups, mean HCV RNA was ⩾ 6 log IU/ml, and 99% of patients had a non-CC IL28B genotype. SVR12 rates were 78% (A1), 65% (A2), 95% (B1), and 95% (B2). In B3, most genotype 1a patients experienced virologic breakthrough. The most common adverse events were headache, diarrhea, and asthenia. Grade 3-4 aminotransferase elevations were infrequent and not treatment-limiting. CONCLUSIONS: In genotype 1 null responders, daclatasvir plus twice-daily asunaprevir DUAL therapy is effective for most genotype 1b patients, and daclatasvir, asunaprevir, and PegIFN/RBV QUAD therapy is effective for nearly all genotype 1a and 1b patients; but neither DUAL nor TRIPLE therapy is effective for genotype 1a patients. Interferon-free regimens including daclatasvir and twice-daily asunaprevir for genotype 1 null responders should be tailored to subtype.

Resistance analysis of hepatitis C virus genotype 1 prior treatment null responders receiving daclatasvir and asunaprevir.

UNLABELLED: In a sentinel cohort, hepatitis C virus (HCV) patients (primarily genotype [GT] 1a) were treated with daclatasvir (NS5A inhibitor) and asunaprevir (NS3 protease inhibitor). Preexistence, emergence, and persistence of resistance variants in patients who failed this treatment are described. HCV-infected null responders received daclatasvir (60 mg once daily) and asunaprevir (600 mg twice daily) alone (Group A, 11 patients) or with peginterferon alfa-2a and ribavirin (Group B, 10 patients) for 24 weeks. Resistance testing was performed on baseline samples and samples with HCV RNA ≥1,000 IU/mL at Week 1 through posttreatment Week 48. Resistance substitution susceptibility to inhibition by asunaprevir and daclatasvir was assessed using HCV replicon assays. In Group A, six GT1a patients experiencing viral breakthrough and one GT1a patient who relapsed had detectable NS5A (Q30E/R, L31V/M, Y93C/N) and NS3 (R155K, D168A/E/V/Y) resistance-associated variants at failure. Two of six viral breakthrough patients achieved SVR48 after treatment intensification with peginterferon alfa-2a and ribavirin. For 2/4 viral breakthrough patients not responding to treatment intensification, NS3 resistance variants changed (D168Y to D168T; R155K to V36M-R155K). At posttreatment Week 48, daclatasvir-resistant variants persisted while asunaprevir-resistant variants were generally replaced by wild-type sequences. The NS3 sequence remained unchanged in the one patient with NS3-R155K at baseline, relapse, and posttreatment Week 48. In Group B, no viral breakthrough was observed. CONCLUSION: The treatment failure of daclatasvir and asunaprevir in HCV GT1a patients was associated with both NS5A and NS3 resistance variants in prior null responders. NS5A resistance variants persisted while NS3 resistance variants generally decayed, suggesting a higher relative fitness of NS5A variants.

Efficacy and safety of daclatasvir plus pegylated-interferon alfa 2a and ribavirin in previously untreated HCV subjects coinfected with HIV and HCV genotype-1: a Phase III, open-label study.

BACKGROUND: Daclatasvir (DCV) is a potent, pangenotypic, hepatitis C virus (HCV) non-structural protein 5A inhibitor with low potential for drug interactions with antiretroviral therapy (ART). We evaluated the safety and efficacy of DCV plus peginterferon alfa-2a/ribavirin (PegIFN/RBV) in HIV-1/HCV genotype-1-coinfected patients. METHODS: AI444043 (NCT01471574), an open-label, Phase III, single-arm, response-guided treatment (RGT) study included 301 patients. They received DCV doses of 30, 60 or 90 mg once daily (depending on concomitant ART), plus weight-based RBV (<75 kg, 1000 mg/day; or ≥75 kg, 1200 mg/day), and once-weekly PegIFN 180 µg, for 24 weeks. If required by RGT, PegIFN/RBV without DCV was extended for an additional 24 weeks of therapy. The primary endpoint was the proportion of patients with sustained virologic response at post-treatment Week 12 (SVR12). RESULTS: Overall, 224 (74%) patients achieved SVR12 and the lower bound of the 95% confidence interval was higher than the historic SVR rate with PegIFN/RBV alone (70 vs. 29%). Most common adverse events (AEs) were fatigue, neutropenia, anemia, asthenia and headache. On-treatment serious AEs occurred in 24/301 (8%) patients; 18/301 (6%) discontinued treatment due to AE. CONCLUSIONS: DCV + PegIFN/RBV led to sustained HCV virologic response in the majority of HIV-1-HCV-coinfected patients, regardless of concomitant ART. HIV control was not compromised and no new safety signals were identified. This study supports DCV use in HIV-1-HCV-coinfected patients, while allowing the vast majority of patients to remain on their existing ART regimen.

The pharmacokinetics of daclatasvir and asunaprevir administered in combination in studies in healthy subjects and patients infected with hepatitis C virus.

BACKGROUND AND OBJECTIVES: The combination of direct-acting antiviral agents in patients with chronic hepatitis C virus (HCV) infection has demonstrated clinical benefit; however, evaluation of potential drug-drug interactions is required prior to therapy. METHODS: An open-label study assessed the pharmacokinetics and tolerability of the HCV NS5A replication complex inhibitor daclatasvir and the HCV NS3 protease inhibitor asunaprevir when co-administered in healthy subjects. Daclatasvir 60 mg once daily and asunaprevir 600 mg twice daily were dosed for 7 days alone followed by combination dosing for 14 days at 30 mg once daily and 200 mg twice daily, respectively. Further assessments were provided comparing exposures from the current study with those from studies in HCV-infected patients receiving either the same or higher doses of daclatasvir or asunaprevir administered alone or together. RESULTS: Dose-normalized daclatasvir and asunaprevir morning exposures were comparable with control in healthy subjects, with geometric mean area under the concentration-time curve ratios of 1.202 (90 % CI 1.113-1.298) and 0.868 (90 % CI 0.726-1.038), respectively. In HCV patients daclatasvir and asunaprevir exposures were largely comparable, when administered together or alone. CONCLUSIONS: Additional data support the conclusion that there is no clinically meaningful interaction between daclatasvir and asunaprevir in either healthy subjects or HCV-infected patients, including those also receiving peginterferon-α/ribavirin, and that the combination of daclatasvir 60 mg once daily and asunaprevir 200 mg twice daily is generally well-tolerated.

Randomized study of asunaprevir plus pegylated interferon-α and ribavirin for previously untreated genotype 1 chronic hepatitis C.

BACKGROUND: Asunaprevir is a selective NS3 protease inhibitor with in vitro activity against HCV genotypes 1 and 4. METHODS: In this Phase IIa double-blind study, treatment-naive HCV genotype-1-infected patients in the United States and France were randomly assigned 1:1:1:1 to placebo or asunaprevir 200 mg twice daily, 600 mg twice daily or 600 mg once daily in combination with pegylated interferon (PEG-IFN)-α2a and ribavirin for 48 weeks. The primary efficacy end point was undetectable HCV RNA at weeks 4 and 12 (extended rapid virological response [eRVR]). Other end points included safety and undetectable HCV RNA at 24 weeks post-treatment (24-week sustained virological response [SVR24]). RESULTS: A total of 47 patients were randomized and treated. eRVR was achieved by 75% (9/12), 75% (9/12) and 92% (11/12) of patients in the asunaprevir 200 mg twice-daily, 600 mg twice-daily and 600 mg once-daily groups, respectively, versus 0% (0/11) in the placebo group. Corresponding SVR24 rates were 83% (10/12), 83% (10/12) and 92% (11/12) in the asunaprevir groups and 46% (5/11) in the placebo group. There was no virological breakthrough in any asunaprevir group. Following the 12-week analysis, the 600 mg doses were reduced to 200 mg twice daily because of a greater frequency of transaminase elevations at the 600 mg dose. The most common grade 3-4 laboratory abnormalities were consistent with those reported for PEG-IFN and ribavirin. CONCLUSIONS: Asunaprevir plus PEG-IFN and ribavirin achieved higher response rates than placebo plus PEG-IFN and ribavirin, with a tolerable adverse event profile at the 200 mg twice-daily dose. This dose is being evaluated in the Phase IIb and Phase III studies.