Virology analysis in HCV genotype 1-infected patients treated with the combination of simeprevir and TMC647055/ritonavir, with and without ribavirin, and JNJ-56914845

Abstract

Background: In study TMC647055HPC2001, a 3-direct-acting-antiviral (DAA) regimen combining NS3/4A protease inhibitor simeprevir (SMV), non-nucleoside NS5B inhibitor TMC647055/ritonavir (RTV) and NS5A inhibitor JNJ-56914845 resulted in high sustained virologic response 12 weeks after actual end of treatment (SVR12) in chronic hepatitis C virus (HCV) genotype 1-infected patients. SVR12 rates were generally lower in the 2-DAA regimen SMV + TMC647055/RTV with or without ribavirin. The objective of this study was to identify and characterise pre-existing and emerging resistance-associated variants (RAVs) in patients enrolled in study TMC647055HPC2001.

Methods: HCV population sequencing analyses were performed on baseline isolates from all patients (n = 90) and post-baseline isolates from patients with virologic failure (n = 22). In addition, deep sequencing and phenotypic analyses were performed on selected baseline and post-baseline isolates.

Results: The majority of patients with virologic failure had emerging RAVs to all study drugs at the time of failure: in all 22 patients SMV RAVs emerged at NS3 positions 80, 155, 156 and/or 168, consistent with the known SMV resistance profile. Emerging TMC647055 RAVs at NS5B position 495 were detected in the majority of patients (16/22), and all 5 patients who failed the 3-DAA regimen had emerging JNJ-56914845 RAVs at NS5A positions 30 and/or 31. While at the end of study emerging SMV and TMC647055 RAVs were no longer observed by population sequencing in 40% (8/20) and 62.5% (10/16) of patients with follow-up data available, respectively, emerging JNJ-56914845 RAVs were still detected in all (5/5) patients.

Conclusions: Virologic failure in the 2- and 3-DAA combinations was, in the majority of patients, associated with the emergence of RAVs to all study drugs. While emerging SMV and TMC647055 RAVs became undetectable during follow-up, JNJ-56914845 RAVs in NS5A were still observed at end of study.

Trial registration number: NCT01724086 (date of registration: September 26, 2012).

Keywords: Genotype 1; Hepatitis C virus; JNJ-56914845; Simeprevir; TMC647055/ritonavir.

Figures

Fig. 1

TMC647055HPC2001 study design. aRibavirin given BID at doses of 1000–1200 mg. bPanel 4 Arm 1 included 1 GT1c- and 1 GT1l-infected patient, based on NS5B-based geno/subtyping. Follow-up therapy with pegIFN + RBV was based on on-treatment response and was initiated only if: week 4 HCV RNA ≥25 IU/mL (Panels 1–3: 36 weeks of follow-up therapy); week 4 HCV RNA <25 IU/mL detectable or HCV RNA confirmed detectable between week 4 and week 11 (Panels 1–2: 12 weeks of follow-up therapy). BID: twice daily; GT: genotype; pegIFN: pegylated interferon; QD: once daily; RBV: ribavirin; RTV: ritonavir; SMV: simeprevir; SVR12: sustained virologic response 12 weeks after actual end of treatment

Fig. 2

Prevalence of NS3 (a), NS5B (b) and NS5A (c) baseline polymorphisms in study TMC647055HPC2001. aFC in EC50 values compared with GT1b wild-type replicon assessed as SDM in a transient replicon assay. bSDM in GT1b replicon backbone. cSDM in GT1a replicon backbone. dSDM data for single Y93C. Baseline NS3 sequencing data were not available for 1 patient (HCV GT1l-infected patient); baseline NS5B and NS5A sequencing data were not available for 2 of the evaluable patients (HCV GT1l-infected patient and HCV GT1c-infected patient). EC50: 50% effective concentration; FC: fold change; GT: genotype; NAP: not applicable; ND: not determined; SDM: site-directed mutant; SMV: simeprevir

Fig. 3

In vitro activity of SMV (a), TMC647055 (b) and JNJ-56914845 (c) against chimeric replicons containing the NS3 protease, NS5B polymerase or NS5A sequences, respectively, from isolates obtained at baseline, time of failure (TOF) and end of study (EOS) or follow-up week 12 (FU W12). Patients with RAVs, as detected by population sequencing in the corresponding plasma samples, are indicated with filled circles; patients without RAVs are indicated with open circles; for three samples at TOF, indicated with an asterisk, the SMV EC50 was above the highest test concentration with a censored FC in EC50 (i.e. >2200); the two isolates with SMV or TMC647055 RAVs detected in the plasma samples at TOF and wild-type sensitivity to SMV and TMC647055, respectively, did not contain these RAVs in the respective sequences included in the chimeric replicons. EC50: 50% effective concentration; EOS: end of study, corresponding to the sample from the last available time point in the study; FC: fold change; FU W12: follow-up week 12, corresponding to the sample obtained at 12 weeks after end of treatment; NAP: not applicable; RAV: resistance-associated variant; SMV: simeprevir; TOF: time of failure, corresponding to the sample obtained at TOF